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Sample records for laser applications final

  1. DOE Center of Excellence in Medical Laser Applications. Final report

    SciTech Connect

    Jacques, S.L. )

    1998-01-01

    An engineering network of collaborating medical laser laboratories are developing laser and optical technologies for medical diagnosis and therapy and are translating the engineering into medical centers in Portland, OR, Houston, TX, and Galveston, TX. The Center includes the University of Texas M.D. Anderson Cancer Center, the University of Texas-Austin, Texas A and M University, Rice University, the University Texas Medical Branch-Galveston, Oregon Medical Laser Center (Providence St. Vincent Medical Center, Oregon Health Sciences University, and Oregon Graduate Institute, Portland, OR), and the University of Oregon. Diagnostics include reflectance, fluorescence, Raman IR, laser photoacoustics, optical coherence tomography, and several new video techniques for spectroscopy and imaging. Therapies include photocoagulation therapy, laser welding, pulsed laser ablation, and light-activated chemotherapy of cancer (photodynamic therapy, or PDT). Medical applications reaching the clinic include optical monitoring of hyperbilirubinemia in newborns, fluorescence detection of cervical dysplasia, laser thrombolysis of blood clots in heart attack and brain stroke, photothermal coagulation of benign prostate hyperplasia, and PDT for both veterinary and human cancer. New technologies include laser optoacoustic imaging of breast tumors and hemorrhage in head trauma and brain stroke, quality control monitoring of dosimetry during PDT for esophageal and lung cancer, polarization video reflectometry of skin cancer, laser welding of artificial tissue replacements, and feedback control of laser welding.

  2. DOE Center of Excellence in Medical Laser Applications. Final report, December 1, 1994--November 30, 1997

    SciTech Connect

    Jacques, S.L.

    1998-01-01

    An engineering network of collaborating medical laser laboratories are developing laser and optical technologies for medical diagnosis and therapy and are translating the engineering into medical centers in Portland OR, Houston TX, and Galveston TX. The Center includes the University of Texas M.D. Anderson Cancer Center, the University of Texas-Austin, Texas A and M University, Rice University, the University Texas Medical Branch-Galveston, Oregon Medical Laser Center (Providence St. Vincent Medical Center, Oregon Health Sciences University, and Oregon Graduate Institute, Portland, OR), and the University of Oregon. Diagnostics include reflectance, fluorescence, Raman IR, laser photoacoustics, optical coherence tomography, and several new video techniques for spectroscopy and imaging. Therapies include photocoagulation therapy, laser welding, pulsed laser ablation, and light-activated chemotherapy of cancer (photodynamic therapy, or PDT). Medical applications reaching the clinic include optical monitoring of hyperbilirubinemia in newborns, fluorescence detection of cervical dysplasia, laser thrombolysis of blood clots in heart attack and brain stroke, photothermal coagulant of benign prostate hyperplasia, and PDT for both veterinary and human cancer. New technologies include laser optoacoustic imaging of breast tumors and hemorrhage in head trauma and brain stroke, quality control monitoring of dosimetry during PDT for esophageal and lung cancer, polarization video reflectometry of skin cancer, laser welding of artificial tissue replacements, and feedback control of laser welding.

  3. Growth of garnet crystals for laser applications. Final report, 1 February-31 July 1984

    SciTech Connect

    Khattak, C.P.

    1984-08-01

    The objective of the Phase I effort was to establish feasibility of growth of Gd3Ga5O12(GGG) crystals as a precursor to growth of other garnet crystals, e.g. Gd35c2Ga3O12 (GSGG), for laser applications. Experimental work showed that Ga/sub 2/O/sub 3/ has a high vapor pressure and, therefore, it results in decomposition of GGG prior to meltdown. Introduction of oxygen into the furnace chamber to prevent decomposition was not feasible with existing graphite resistance-heated HEM furnaces. An alternative material in the Al-garnet family, Gd3Sc2Al3O12 (GSAG), was chosen. The higher stability of the melt suggests that low intrinsic defects containing larger crystals of GSAG can be grown as compared to GSGG. This new class of garnet-structured crystals offers potential for high-power, tunable, solid-state laser materials.

  4. Mode locked fiber lasers and their applications. Final report, December 1993-December 1994

    SciTech Connect

    Teegarden, K.J.

    1996-01-01

    This work has resulted in the development of a compact self-starting modelocked erbium fiber laser. The remarkable feature is the elimination of the need for any type of polarization control. Furthermore, all of the components are passive and are contained within the fiber cavity medium itself. This permits an ultra compact modular system that is portable. The laser employs a Fabry-Perot cavity with a fiber grating as one reflector, and a nonlinear multiple quantum well saturable absorber as the other. It operates at low pump power from a LP and produces pico second modelocked pulses with peak powers of over 20 W. When the saturable absorber is sized to a sub-millimeter dimension and micro-assembled on the fiber tip, all need for alignment is removed and the system is completely portable and fairly rugged. The transform limited chirp free characteristics of the ultra short pulses enable soliton propagation effects to minimize pulse broadening that limits the rates/distance in all present systems. These fiber lasers are presently suitable for device diagnostics, but may ultimately prove superior to the laser diode sources presently used in all high rate fiber optic communication and sensor systems.

  5. Laser applications in neurosurgery

    NASA Astrophysics Data System (ADS)

    Cerullo, Leonard J.

    1985-09-01

    beam makes the laser superior to all conventional destructive instruments. 4)|The coagulative properties of certain chromophoric lasers has allowed a new attack on certain vascular tumors and malformations of the brain and spinal cord which had been operated only with trepidation or not at all. Early reports are sobering but encouraging. 5)|Finally, the use of the laser with tissue photosensitization, albeit it in its infancy, offers great promise. This is particularly true in the case of primary brain cancer, where the infiltration of tumorous tissue among normal pathways precludes the classical oncologic surgery practice of resection of a "safe margin". The ability to track and destroy these cells, without affecting adjacent cells, may be the greatest single contribution of the laser to neurosurgery in the future. The present applications of the laser are relatively crude by comparison with what is expected. Endoscopic laser surgery, both vascular and subarachnoid, will diminish morbidity and improve results. From the exotic treatment of aneurysms and arteriovenous malformations of the brain to the mundane care of herniated disks of the spine, it is anticipated that the laser will play an important role. The use of a laser, coupled with computerized imagining devices, will allow increasing precision in arrival to and treatment of deep seated lesions of the brain, brainstem, and spinal cord. The use of different wavelengths, perhaps in the X-ray and ultraviolet spectra, will allow increasing precision with decreasing invasion. Manipulation of wavelength, time, and treatment area will allow subcellular surgery, perhaps in the treatment of personality disorders and movement disorders as well as epilepsy. Tissue welding will allow heightened regenerative and recuperative powers to be exploited. The possibility of laser biostimulation must also be considered. In short, it appears that the future of the laser in neurosurgery is limited only by the imagination of the

  6. Laser Damage Inspection Final Report

    SciTech Connect

    Salmon, J T; Brase, J M; Bliss, E S; Carrano, C J; Kegelmeyer, L M; Miller, M G; Orth, C D; Sacks, R A

    2001-02-26

    and characterization in dark and bright field images. Supporting tasks include the collection of experimental images from a physical model of a representative beamline of a high-power laser and development of a propagation model of the same beamline. This beamline includes multipass amplifiers and spatial filters. While the experimental model and the numerical model used to verify the algorithms presented here are of a specific architecture, the general image processing approach taken here should be applicable to any high-power laser system. Our approach to image processing development has three main components. First, determine the smallest detectable defect. Second, determine the accuracy of the measurement of a defect that is 25% of the critical size. Third, develop and demonstrate a process for inspecting the set of spatial filter optics that would normally be vacuum-loaded in an actual high-power laser system. The method must account for multiple passes and nearly overlapping multiple conjugate planes in the beamline.

  7. Laser applications in phlebology

    NASA Astrophysics Data System (ADS)

    Longo, Leonardo; Mancini, S.; Postiglione, Marco; Postiglione, M. G.

    2001-06-01

    PURPOSE: review of laser used in phlebology METHOD: critical analysis of scientific data taken from the literature and based on 25 years personal experience. RESULTS: we have three groups of laser applications in phlebology: for the diagnosis, as physical therapy and as surgical therapy. DISCUSSION AND CONCLUSION: the laser-doppler studies the microcirculations, the no-surgical therapy shown positive results in the treatment of venous ulcers and for the wound healing. It could be indicate also as antiphlogistic and anti-edema therapy, in superficial thrombophlebitis. The surgical laser is useful for the surgical cleaning of ulcers, for haemorroids, angiomas and telangiectases.

  8. ): laser processing and applications

    NASA Astrophysics Data System (ADS)

    Fricke-Begemann, T.; Meinertz, J.; Weichenhain-Schriever, R.; Ihlemann, J.

    2014-10-01

    Substoichiometric silicon oxide SiOx with x < 2 in form of evaporated or sputtered thin films offers a versatile material basis for laser ablation techniques such as film patterning, laser-induced forward transfer, or laser-induced backside dry etching. Applications in the field of (micro-) optics are favoured strongly by the fact that SiOx can be oxidised to UV-transparent SiO2 by thermal treatment (furnace or laser annealing). On the other hand, with x ≈ 1, SiOx exhibits an absorption coefficient of >105 cm-1 in the deep UV below 250 nm, comparable to strongly absorbing polymers such as polyimide. This enables precise ablation with, e.g., excimer lasers at moderate fluences. For example, UV-transparent diffractive elements or phase masks are made by laser patterning of an appropriate SiOx film and subsequent oxidation to SiO2. Modifications of the basic film ablation process lead to novel surface topographies such as blister or cup arrays with potential non-optical applications, e.g., in micro-/nanofluidics.

  9. Laser diode initiated detonators for space applications

    NASA Technical Reports Server (NTRS)

    Ewick, David W.; Graham, J. A.; Hawley, J. D.

    1993-01-01

    Ensign Bickford Aerospace Company (EBAC) has over ten years of experience in the design and development of laser ordnance systems. Recent efforts have focused on the development of laser diode ordnance systems for space applications. Because the laser initiated detonators contain only insensitive secondary explosives, a high degree of system safety is achieved. Typical performance characteristics of a laser diode initiated detonator are described in this paper, including all-fire level, function time, and output. A finite difference model used at EBAC to predict detonator performance, is described and calculated results are compared to experimental data. Finally, the use of statistically designed experiments to evaluate performance of laser initiated detonators is discussed.

  10. Applications of Ion Laser Systems

    NASA Astrophysics Data System (ADS)

    Fletcher, Peter W.

    1987-04-01

    This paper provides an introduction to the more common applications of ion laser systems. Applications discussed include photocoagulation, flow cytometry, laser disk mastering, laser doppler velocimetry, Raman spectroscopy, holography, laser light shows, large screen projection, fingerprint detection, and applications in printing such as color separation and scanning. All these applications are currently in widespread use. At the end of the paper a short review is provided of developing applications such as cardiovascular surgery and semiconductor processing.

  11. Medical applications of semiconductor lasers

    NASA Astrophysics Data System (ADS)

    Mancha, Sylvia D.; Keipert, Andreas; Prairie, Michael W.

    1994-06-01

    The High Power Semiconductor Laser Technology (HPSLT) program is currently developing, in-house, a belt pack medical laser. This compact semiconductor laser device provides the field paramedic or physician a unique portable laser capability. The pack consists of a completely self-contained laser system that fits inside a belt pack. Several other medical applications being investigated by the HPSLT program include urological applications, photodynamic therapy, and ophthalmic applications.

  12. New laser materials: Final report

    SciTech Connect

    Not Available

    1986-10-01

    In the Interim Report No. 1, it was reported that the fluorescence lifetime (greater than or equal to 750..mu..s) in Nd doped Y(PO/sub 3/)/sub 3/ was longer by a factor of three as compared to YAG. This means potentially three times as much energy storage and consequently more efficient for flashlamp pumping. It also makes diode pumping easier. In addition, since the Y site is octahedrally coordinated, there is a possibility of energy transfer using Cr as the sensitizing element. As suggested by W. Krupke, we decided to explore the trivalent cation metaphosphates systematically. The compounds investigated can be represented by the general formula A(PO/sub 3/)/sub 3/ where A = Y, Lu, In, Sc, GA and Al. The object is to study the fluorescence characteristics of Nd and Cr as well as the effectiveness of energy transfer from Cr to Nd. In addition, we also investigated other possible laser host crystals, notably CaMgSi/sub 2/O/sub 6/ (diopside), LaBO/sub 3/ and La(BO/sub 2/)/sub 3/. Results on these materials will also be discussed.

  13. Novel oral laser applications

    NASA Astrophysics Data System (ADS)

    Yousif, A.; Strassl, M.; Beer, F.; Verhagen, L.; Wittschier, M.; Wintner, E.

    2007-03-01

    In dental hard tissue ablation, ultra-short laser pulses have proven sufficiently their potential for material ablation with negligible collateral damage providing many advantages. The absence of micro-cracks and the possibility to avoid overheating of the pulp during dental cavity preparation may be among the most important issues, the latter opening up an avenue for potential painless treatment. Beside the evident short interaction time of laser radiation with the irradiated tissue, scanning of the ultra-short pulse trains turned out to be crucial for ablating cavities of required quality and shape. Additionally, long-pulsed laser systems have demonstrated successfully their suitability for decontamination purposes. In this paper, an overview of different indications for laser application in dental therapies in both pulse regimes is presented. A special focus is set on the decontamination of dental implants in periimplantitis therapy. Having employed commercially available long pulse systems for dental applications and ultra-short 330 fs pulses, we present first results for temperature development and corresponding ablation thresholds for dental implants, as in the future more gentle implant cleaning by ultra-short laser pulses could become of interest.

  14. FY 2005 Laser Development Final Report

    SciTech Connect

    Phillips, Mark C.; Myers, Tanya L.; Taubman, Matthew S.

    2005-12-01

    The Laser Development Task of Pacific Northwest National Laboratory's (PNNL) Remote Spectroscopy project (PL211I) is focused on the development of novel laser technology for a new generation of standoff and in-situ chemical sensors for detecting the proliferation of nuclear weapons. These lasers will improve the sensitivity, flexibility, or range of active standoff sensors, enable ultra-trace in situ sensors with enhanced selectivity, as well as greatly improve calibration of passive standoff sensors. In particular, laser transmitters with minimal size, weight, and power consumption (SWAP) are needed to meet the requirements for a variety of in situ or short-range stand-off sensors and sensors for small UAVs or other platforms. These laser transmitters need to be rugged and free of requirements for consumables such as liquid nitrogen. Many sensing techniques also require lasers that produce a single narrow wavelength (single longitudinal mode). Lasers that provide high continuous-wave (CW) output power on a single line at operating temperatures accessible with thermoelectric (TE) cooling are therefore essential for sensor applications.

  15. Final Report: Cooling Molecules with Laser Light

    SciTech Connect

    Di Rosa, Michael D.

    2012-05-08

    Certain diatomic molecules are disposed to laser cooling in the way successfully applied to certain atoms and that ushered in a revolution in ultracold atomic physics, an identification first made at Los Alamos and which took root during this program. Despite their manipulation into numerous achievements, atoms are nonetheless mundane denizens of the quantum world. Molecules, on the other hand, with their internal degrees of freedom and rich dynamical interplay, provide considerably more complexity. Two main goals of this program were to demonstrate the feasibility of laser-cooling molecules to the same temperatures as laser-cooled atoms and introduce a means for collecting laser-cooled molecules into dense ensembles, a foundational start of studies and applications of ultracold matter without equivalence in atomic systems.

  16. Laser applications in criminalistics

    NASA Astrophysics Data System (ADS)

    Menzel, E. R.

    1990-10-01

    Lasers find application in numerous areas of criminalistics such as fiber analysis document examination and serology. Their widest use however is in detection of latent finger prints. Several routine procedures for obtaining laserexcited fingerprint fluorescence on a range of surfaces have been devel oped. However many surfaces fluoresce so strongly themselves that they are not amenable to these procedures. Timeresolved luminescence imaging is being investigated to permit detection of fingerprints on such surfaces.

  17. Soft tissue application of lasers.

    PubMed

    Holt, Timothy L; Mann, Fred A

    2002-05-01

    Despite increasing numbers of veterinarians incorporating lasers into their clinical practices, little information has been published about laser clinical applications in soft tissue surgery. This article reviews soft tissue interaction, describes laser equipment and accessories commonly marketed to veterinarians, and discusses clinical applications of the carbon dioxide laser in a systems-based approach. A table of recommended laser tips and settings based on the authors' experiences using a carbon dioxide laser (AccuVet Novapulse LX-20SP, Bothell, WA) is provided. PMID:12064042

  18. Development of portable laser machining system for laser writing applications

    NASA Astrophysics Data System (ADS)

    Hsiao, Wen-Tse; Tseng, Shih-Feng; Chung, Chien-Kai; Chen, Pin-Hung; Chen, Ming-Fei

    2013-03-01

    This study presents a portable laser machining system that consists of a fiber-optic diode laser source with a wavelength of 808 nm, optic/opto-mechanical components, a laser scanning module, and a laser energy control module. The laser beam quality was measured at different operation frequencies during system evaluation. The experimental results of beam profile evaluation indicate that the enlarged collimated beam was the TEM00 mode with a roundness of approximately of 96%. The output laser power level increased as the pulse frequency increased during laser power evaluation. To control the rotating angle of the galvanometric scanning system, the deflective angle was adjusted using a 0.192 voltage to obtain a deflective value of 1mm and the maximum scan field of 100 × 100mm2. The laser source operated at different frequencies, with pulse widths ranging from 530 to 48 μs. Finally, the proposed machine can also be used for black thick paper laser writing applications.

  19. Diode laser applications in urology

    NASA Astrophysics Data System (ADS)

    Sam, Richard C.; Esch, Victor C.

    1995-05-01

    Diode lasers are air-cooled, efficient, compact devices which have the potential of very low cost when produced in quantity. The characteristics of diode lasers are discussed. Their applications in interstitial thermal treatment of the prostate, and laser ablation of prostate tissues, will be presented.

  20. The lasers for TMLR application

    NASA Astrophysics Data System (ADS)

    Panchenko, Vladislav Y.; Berishvili, I. I.; Vasiltsov, Victor V.; Ulyanov, Valerii A.; Egorov, E. N.; Solovjev, Andrey V.; Semenov, A. N.; Tarasov, M. N.; Roshin, M. A.

    2004-06-01

    The paper presents the analysis of the requirements to the laser systems used to cure the ischemic disease of the heart by the method of transmyocardial laser revascularization (TMLR). Among the medical laser systems under discussion (solid-state Nd:YAG, Er:YAG, Ho:YAG, excimer lasers, etc.) the high-power CO2 laser with pulse energy to 40 J is most suited to produce channels in the heart muscle. The paper provides the description and the technical characteristics of medical laser systems of "Perfocor" series, based on high-power waveguide CO2 lasers with pulse energy to 60 J, developed at ILIT RAS. The methods to determine the time of laser radiation penetration through the myocardium/blood boundary have been briefly discussed. The application of the "Perfocor" system in other laser operations on blood-filled organs has also been discussed.

  1. Low-energy x-ray and electron physics and applications to diagnostics development for laser-produced plasma research. Final report, April 30, 1980-April 29, 1981

    SciTech Connect

    Henke, B.L.

    1981-08-01

    This final report describes a collaborative extension of an ongoing research program in low-energy x-ray and electron physics into particular areas of immediate need for the diagnostics of plasmas as involved in laser-produced fusion research. It has been for the continued support for one year of a post-doctoral research associate and for three student research assistants who have been applied to the following specific efforts: (1) the continuation of our research on the absolute characterization of x-ray photocathode systems for the 0.1 to 10 keV photon energy region. The research results were applied collaboratively to the design, construction and calibration of photocathodes for time-resolved detection with the XRD and the streak and framing cameras; (2) the design, construction and absolute calibration of optimized, bolt-on spectrographs for the absolute measurement of laser-produced plasma spectra.

  2. Laser Doppler vibration testing: Final report. [Under difficult conditions

    SciTech Connect

    Assa, A.S.; Mannara, S.R.

    1987-05-01

    This report summarizes work under EPRI project RP1855-2 conducted toward the objective of developing utility applications for a noncontacting laser Doppler vibration (LDV) measurement instrument. As part of the program, a dual beam laser doppler system was designed and fabricated in-house for the measurement of torsional vibrations of shafts. Laboratory tests were performed with this instrument to evaluate various signal processing approaches, and characterize the LDV performance with different laser powers and on several surface roughnesses. A factory test simulating field conditions was conducted on a full-size large steam turbine-generator rotor. The test was successful with the accuracy and linearity of the laser system within 10% of a reference measurement. Following the work on the dual beam system, work was directed toward field test evaluations of a portable reference beam laser doppler vibrometer. A main objective was to see if the LDV could perform satisfactorily under the rigors of a utility environment. Successful vibration measurements were taken on turbine steam leads at 1000/sup 0/F (without requiring unit shutdown), on heat exchanger tubes inside an operating boiler, from a rotating shaft, and from a black carbon collector brush at 500 volts. In the final test at United Illuminating Co., vibration data were obtained without unit shutdown from the generator neutral isophase bus lines with 13,000 amps of current in the line.

  3. Novel fiber lasers and applications

    NASA Astrophysics Data System (ADS)

    Zenteno, Luis A.; Walton, Donnell T.

    2003-07-01

    Glass fiber lasers were invented in the 60's by Elias Snitzer at Americal Optical, soon after the invention of the first solid-state glass laser. However, it was not until the 80's when these waveguide devices were deployed in industrial applications, driven largely by the technological success of the semiconductor laser diode, which provided practical and efficient pumps, and by the advent of low loss rare-earth-doped optical fiber.

  4. Application of lasers in endodontics

    NASA Astrophysics Data System (ADS)

    Ertl, Thomas P.; Benthin, Hartmut; Majaron, Boris; Mueller, Gerhard J.

    1997-12-01

    Root canal treatment is still a problem in dentistry. Very often the conventional treatment fails and several treatment sessions are necessary to save the tooth from root resection or extraction. Application of lasers may help in this situation. Bacteria reduction has been demonstrated both in vitro and clinically and is either based on laser induced thermal effects or by using an ultraviolet light source. Root canal cleansing is possible by Er:YAG/YSGG-Lasers, using the hydrodynamic motion of a fluid filled in the canals. However root canal shaping using lasers is still a problem. Via falsas and fiber breakage are points of research.

  5. High-power laser diodes, laser diode modules, and their applications

    NASA Astrophysics Data System (ADS)

    Daiminger, Franz X.; Dorsch, Friedhelm; Lorenzen, Dirk

    1998-12-01

    High power laser diodes and especially high power laser diode modules made enormous progress in the last few years. Different aspects of high power laser diodes are treated starting from general description of high power laser diodes and their mounting techniques, characterizing the electro- optical behavior of single laser bars and finally presenting beamshaping optics for the collimation of large modules. The later technique allows for symmetrical focal spots in the kilowatt range with a beam quality of about 170 mm*mrad. Different aspects of current applications of high power laser diodes are presented.

  6. Laser scribe optimization study. Final report

    SciTech Connect

    Wannamaker, A.L.

    1996-09-01

    The laser scribe characterization/optimization project was initiated to better understand what factors influence response variables of the laser marking process. The laser marking system is utilized to indelibly identify weapon system components. Many components have limited field life, and traceability to production origin is critical. In many cases, the reliability of the weapon system and the safety of the users can be attributed to individual and subassembly component fabrication processes. Laser beam penetration of the substrate material may affect product function. The design agency for the DOE had requested that Federal Manufacturing and Technologies characterize the laser marking process and implement controls on critical process parameters.

  7. Laser Science and Applications

    NASA Astrophysics Data System (ADS)

    El-Nadi, Lotfia M.; Mansour, Mohy S.

    2010-04-01

    Attosecond high harmonic pulses: generation and characterization / C. H. Nam and K. T. Kim -- High power lasers and interactions / C. Chatwin and R. Young -- Laser accelerators / L. M. El-Nadi ... [et al.] -- Energy levels, oscillator strengths, lifetimes, and gain distributions of S VII, CI VIII, and Ar IX / Wessameldin. S. Abdelaziz and Th. M. El-Sherbini -- The gain distribution according to theoretical level structure and decay dynamics of W[symbol] / H. M. Hamed ... [et al.] -- Raman spectroscopy and low temperature photoluminescence ZnSe[symbol]Te[symbol] ternary alloys / A. Salah ... [et al.] -- Automated polarization-discrimination technique to minimize lidar detected skylight background noise, part I / Y. Y. Hassebo, K. Elsayed and S. Ahmed -- Laser interferometric measurements of the physical properties for He, Ne gases and their mixture / N. M. Abdel-Moniem ... [et al.] -- Analytical studies of laser beam propagation through the atmosphere / M. I. El-Saftawy, A. M. Abd El-Hamed and N. Sh. Kalifa -- Laser techniques in conservation of artworks: problems and breakthroughs / R. Salimbeni and S. Siano -- Technology-aided heritage conservation laser cleaning for buildings / M. S. Nada -- Technology significance in conservation of the built heritage 3D visualization impact / M. S. Nada -- Simulation of optical resonators for Vertical-Cavity Surface-Emitting Lasers (VCSEL) / M. S. Mansour ... [et al.] -- Optical design alternatives: a survey study / A. A. K. Ismail, I. A. S. Ismail and S. H. Ahmed -- Materials for digital optical design; a survey study / A. A. K. Ismail, I. A. S. Ismail and S. H. Ahmed -- Proposed design for optical digital circuits / A. A. K. Ismail, I. A. S. Ismail and S. H. Ahmed -- Photo-induced effect on bacterial cells / M. H. El Batanouny ... [et al.] -- Laser and non-coherent light effect on peripheral blood normal and acute lymphoblastic leukemic cells by using different types of photosensitizers / M. H. El Batanouny ... [et al

  8. Optofluidic lasers and their applications in bioanalysis (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Fan, Xudong

    2016-03-01

    The optofluidic laser is an emerging technology that integrates microfluidics, miniaturized laser cavity, and laser gain medium in liquid. It is unique due to its biocompatibility, thus can be used for unconventional bioanalysis, in which biointeraction or process takes place within the optical cavity mode volume. Rather than using fluorescence, the optofluidic laser based detection employs laser emission, i.e., stimulated emission, as the sensing signal, which takes advantage of optical amplification provided by the laser cavity to achieve much higher sensitivity. In this presentation, I will first introduce the concept of optofluidic laser based bioanalysis. Then I will discuss each of the three components (cavity, gain medium, and fluidics) of the optofluidic laser and describe how to use the optofluidic laser in bioanalysis at the molecular, cellular, and tissue level. Finally, I will discuss future research and application directions.

  9. Final Report - DOE Center for Laser Imaging and Cancer Diagnostics

    SciTech Connect

    Alfano, Robert R.; Koutcher, Jason A.

    2002-10-31

    This Final Report summarizes the significant progress made by the researchers, students and staff of the Center for Laser Imaging and Cancer Diagnostics (CLICD) from January 1998 through May 2002. During this period, the Center supported several projects. Most projects were proposed initially, some were added subsequently as their relevance and importance to the DOE mission became evident. DOE support has been leveraged to obtain continuing funding for some projects. Leveraged funds come from various sources, including NIH, Army, NSF and the Air Force. The goal of the Center was to develop laser-based instruments for use in the detection and diagnosis of major diseases, with an emphasis on detection and diagnosis of various cancers. Each of the supported projects is a collaborative effort between physicists and laser scientists and the City College of New York and noted physicians, surgeons, pathologists, and biologists located at medical centers in the Metropolitan area. The participating institutions were: City College of New York Institute for Ultrafast Lasers and Spectroscopy, Hackensack University Medical Center, Lawrence Livermore National Laboratory, Memorial Sloan Kettering Cancer Center, and New York Eye and Ear Institute. Each of the projects funded by the Center is grouped into one of four research categories: a) Disease Detection, b) Non-Disease Applications, c) New Diagnostic Tools, and, d) Education, Training, Outreach and Dissemination. The progress achieved by the multidisciplinary teams was reported in 51 publications and 32 presentations at major national conferences. Also, one U.S. patent was obtained and six U.S. patent applications have been filed for innovations resulting from the projects sponsored by the Center.

  10. Argon laser application to endodontics

    NASA Astrophysics Data System (ADS)

    Blankenau, Richard J.; Ludlow, Marvin; Anderson, David

    1993-07-01

    The application of laser technology to endodontics has been studied for some time. At the present time several major problems are being investigated: (1) removal of infected tissues, (2) sterilization of canals, (3) obturation of canals, and (4) preservation of the vitality of supporting tissues. This list is not intended to imply other problems do not exist or have been solved, but it is a starting point. This paper reviews some of the literature that relates to laser applications to endodontics and concludes with some of the findings from our investigation.

  11. Semiconductor laser applications in rheumatology

    NASA Astrophysics Data System (ADS)

    Pascu, Mihail-Lucian; Suteanu, S.

    1996-01-01

    Two types of laser diode (LD) based equipment for rheumatology are introduced. The first is a portable device which contains single LD emitting at 890 nm laser pulses (time full width 100 nsec) of reprate tunable within (0.5 - 1.5) kHz; the laser beam average power is 0.7 mW at 1 kHz reprate. The second is computer controlled, contains one HeNe laser and 5 LD allowing 6 modes of patient irradiation (placebo effect evaluation included). HeNe laser works in cw at 632.8 nm; the LD works each as described for the portable equipment. HeNe and LD beams are superposed so that HeNe laser spot in the irradiation plane has a 60 mm diameter and the LD spots covers a 50 mm diameter disc centered on the HeNe laser spot. Clinical applications using the second type of equipment are reported; 1287 patients were treated between October 1991 and October 1994. Female/male ratio was 4:1 and their age distribution was between 18 and 85 years. The average number of exposures was 10 and the mean exposure time was 7 minutes. Studies were made on the treatment of rheumatoid arthritis, seronegative arthritis, degenerative joint diseases, abarticular rheumatism, osteoporosis pain and pains and edema after fractures.

  12. Laser spectroscopy and its applications

    SciTech Connect

    Radziemski, L.J.; Solarz, R.W.; Paisner, J.A.

    1987-01-01

    Laser spectroscopy has applications in diverse fields ranging from combustion studies and trace-sample detection to biological research. At the same time, it has also contributed greatly to the discovery of hundreds of new lasers. This symbiotic relationship has promoted an especially rapid expansion of the field. This book provides a review of the subject. It includes, for example, chapters on laser isotope separation techniques, enabling scientists to compare their relative advantages and drawbacks. This volume also gives numerous tables that summarize important features of lasers, experiments, and parameters for quick reference. In addition, it presents diagrams for visualizing rotational molecular energy levels of high J in order to enhance our understanding of molecular motions and their relationship to molecular energy levels. Offering insights into how experts think this technology will improve, it considers research and development in each topic discussed.

  13. Laser Applications: Implications for Vocational Education.

    ERIC Educational Resources Information Center

    Fraser, Jeannette L.

    Recent and projected advances in and commercial applications of lasers and laser technology were examined in order to assist vocational planners in responding to skill needs that will be created by lasers in the next few years. Until recently, most laser applications were in research and development settings; however, in the last several years…

  14. Statistical fluctuation in lasers. Final technical report

    SciTech Connect

    Roy, R.

    1997-10-17

    The authors have investigated the stability of coupled laser systems and proposed a new scheme for communication using chaotic carrier waves. Such schemes utilize the ability of chaotic lasers to synchronize in both phase and amplitude. Statistical fluctuations of the light emitted by erbium doped fiber lasers at nanosecond time scales have been studied both experimentally and theoretically, and a new model using coupled delay-differential equations has been developed to explain the complex temporal patterns measured. Four wave mixing in optical fibers has been extensively investigated and modifications to standard models developed to explain the observations.

  15. Diode-Laser Phase Conjugation 03-FS-030 Final Report

    SciTech Connect

    Page, R H; Beach, R J; Payne, S A; Holzrichter, J F

    2005-02-14

    Arrays of lasers are often considered when a need exists to increase laser optical output power, for a variety of purposes. Similarly, individual semiconductor laser-diodes, generating 0.01-1.0 W each, are commonly placed in arrays in order to increase total optical power onto targeted objects. Examples of such usage are diode-laser pump arrays for solid-slab heat-capacity lasers, laser arrays for heat-treating materials, and arrays for efficient solid state laser systems. The commercial and defense communities also use such arrays for many applications from laser range-finders, laser designators, to laser machining systems, etc. However, the arraying process does not automatically increase ''focusable'' light on target (i.e., intensity/steradian). For those applications requiring the highest focusability, it is necessary that the collective output beam from arrays of individual lasers be phase-coherent. Under this condition, the individual laser-element optical outputs are ''fused together'' into a larger area, phase coherent (i.e., all wavefronts are ''in step''), high-power combined beam. The process of joining multiple laser beams together to produce a single coherent wave, is in general very difficult and seldom accomplished. Thus joining together many hundreds to thousands of beams from individual laser-diodes, in large arrays, is still an unsolved problem. There are 2 major reasons for this. Firstly, the phase of each output laser beam (i.e. the wave-fronts) from each laser diode often fluctuates within nanosecond time periods, making a control loop with sufficient bandwidth difficult to build. In fact, phase fluctuations (related to laser linewidth) limit the size of an extended system of arrayed diodes because of speed-of-light restrictions on information flow. Secondly, the output power per prior laser diode has been low ( < 1W,) so that the size, expense, and complexity of control systems for correcting a multitude of output phases of the individual

  16. Applications of lasers and electro-optics

    NASA Astrophysics Data System (ADS)

    Tan, B. C.; Low, K. S.; Chen, Y. H.; Ahmad, Harith; Tou, T. Y.

    Supported by the IRPA Programme on Laser Technology and Applications, many types of lasers have been designed, constructed and applied in various areas of science, medicine and industries. Amongst these lasers constructed were high power carbon dioxide lasers, rare gas halide excimer lasers, solid state Neodymium-YAG lasers, nitrogen lasers, flashlamp pumped dye lasers and nitrogen and excimer laser pumped dye lasers. These lasers and the associated electro-optics system, some with computer controlled, are designed and developed for the following areas of applications: (1) industrial applications of high power carbon dioxide lasers for making of i.c. components and other materials processing purposes -- prototype operational systems have been developed; (2) Medical applications of lasers for cancer treatment using the technique of photodynamic therapy -- a new and more effective treatment protocol has been proposed; (3) agricultural applications of lasers in palm oil and palm fruit-fluorescence diagnostic studies -- fruit ripeness signature has been developed and palm oil oxidation level were investigated; (4) development of atmospheric pollution monitoring systems using laser lidar techniques -- laboratory scale systems were developed; and (5) other applications of lasers including laser holographic and interferometric methods for the non destructive testing of materials.

  17. Expanded mode lasers for telecommunications applications

    NASA Astrophysics Data System (ADS)

    Lealman, Ian F.

    This thesis describes the development of a long wavelength (1.55 μm) expanded mode semiconductor laser. The increased spot size of the laser improves both the coupling efficiency to cleaved fibre and fibre alignment tolerances and reduces packaging cost. In this type of device the strength of the waveguide is gradually reduced towards the front facet allowing the mode to adiabatically expand so that the laser mode is better matched in size to that of a cleaved fibre. This can be achieved by either reducing the refractive index of the guide or reducing the amount of material in the core. The structure chosen was a buried heterostructure laser that utilised a twin guide consisting of an upper higher refractive index guide (the active region of the laser) above a weak passive guide. The width of the active region was reduced along part of the device allowing the mode to expand into the weak underlying guide. The guide structure was optimised using a variable grid finite difference mode solver, and the taper length calculated by an approximation to Love's method. Detailed results are presented for the measured light-current characteristic, farfield and coupling loss to cleaved fibre. These coupling losses were compared to the calculated data thus allowing the waveguide design to be optimised. Several iterations in the design of the device were undertaken, with the aim of reducing the coupling loss to cleaved single mode fibre without significantly compromising the laser performance. The final device design had extremely low coupling losses as low as 1.2 dB to cleaved fibre. Finally, the positive impact this device had on passive alignment using a silicon motherboard is examined, and the application this technology to a range of other optoelectronic components is discussed.

  18. Space tug applications. Final report

    SciTech Connect

    1996-01-01

    This article is the final report of the conceptual design efforts for a `space tug`. It includes preliminary efforts, mission analysis, configuration analysis, impact analysis, and conclusions. Of the several concepts evaluated, the nuclear bimodal tug was one of the top candidates, with the two options being the NEBA-1 and NEBA-3 systems. Several potential tug benefits were identified during the mission analysis. The tug enables delivery of large (>3,500 kg) payloads to the outer planets and it increases the GSO delivery capability by 20% relative to current systems. By providing end of life disposal, the tug can be used to extend the life of existing space assets. It can also be used to reboost satellites which were not delivered to their final orbit by the launch system. A specific mission model is the key to validating the tug concept. Once a mission model can be established, mission analysis can be used to determine more precise propellant quantities and burn times. In addition, the specific payloads can be evaluated for mass and volume capability with the launch systems. Results of the economic analysis will be dependent on the total years of operations and the number of missions in the mission model. The mission applications evaluated during this phase drove the need for large propellant quantities and thus did not allow the payloads to step down to smaller and less expensive launch systems.

  19. [Applications of lasers in dental implantology].

    PubMed

    Mu, Yue; Li, Qian; Zhao, Ji-zhi

    2014-10-01

    With the constant progress of laser physics, medical laser technology has been widely applied in clinical practices and basic researches. In this article, we reviewed the relevant articles on the laser applications in dental implantology and concluded that lasers provides promising solutions in the treatment technology of dental implants and in the treatment of soft and hard tissue conditions.

  20. [The application of laser in endodontics].

    PubMed

    He, W X; Liu, N N; Wang, X L; He, X Y

    2016-08-01

    Since laser was introduced in the field of medicine in 1970's, its application range has continuously expanded. The application of laser in endodontics also increased due to its safety and effectiveness in dental treatments. The majority of the laser application researches in dentistry focused on dentin hypersensitivity, removal of carious tissues, tooth preparations, pulp capping or pulpotomy, and root canal treatment. In this article, we reviewed literature on the effects of laser in the treatments of dental and pulp diseases. PMID:27511037

  1. Long pulse chemical laser. Final technical report

    SciTech Connect

    Bardon, R.L.; Breidenthal, R.E.; Buonadonna, V.R.

    1989-02-01

    This report covers the technical effort through February, 1989. This effort was directed towards the technology associated with the development of a large scale, long pulse DF-CO{sub 2} chemical laser. Optics damage studies performed under Task 1 assessed damage thresholds for diamond-turned salt windows. Task 2 is a multi-faceted task involving the use of PHOCL-50 for laser gain measurements, LTI experiments, and detector testing by LANL personnel. To support these latter tests, PHOCL-50 was upgraded with Boeing funding to incorporate a full aperture outcoupler that increased its energy output by over a factor of 3, to a full kilojoule. The PHOCL-50 carbon block calorimeter was also recalibrated and compared with the LANL Scientech meter. Cloud clearing studies under Task 3 initially concentrated on delivering a Boeing built Cloud Simulation Facility to LANL, and currently involves design of a Cold Cloud Simulation Facility. A Boeing IRAD funded theoretical study on cold cloud clearing revealed that ice clouds may be easier to clear then warm clouds. Task 4 involves the theoretical and experimental study of flow system design as related to laser beam quality. Present efforts on this task are concentrating on temperature gradients induced by the gas filling process. General support for the LPCL field effort is listed under Task 5, with heavy emphasis on assuring reliable operation of the Boeing built Large Slide Valve and other device related tests. The modification of the PHOCL-50 system for testing long pulse DF (4{mu}m only) chemical laser operation is being done under Task 6.

  2. Medical laser application: translation into the clinics

    NASA Astrophysics Data System (ADS)

    Sroka, Ronald; Stepp, Herbert; Hennig, Georg; Brittenham, Gary M.; Rühm, Adrian; Lilge, Lothar

    2015-06-01

    Medical laser applications based on widespread research and development is a very dynamic and increasingly popular field from an ecological as well as an economic point of view. Conferences and personal communication are necessary to identify specific requests and potential unmet needs in this multi- and interdisciplinary discipline. Precise gathering of all information on innovative, new, or renewed techniques is necessary to design medical devices for introduction into clinical applications and finally to become established for routine treatment or diagnosis. Five examples of successfully addressed clinical requests are described to show the long-term endurance in developing light-based innovative clinical concepts and devices. Starting from laboratory medicine, a noninvasive approach to detect signals related to iron deficiency is shown. Based upon photosensitization, fluorescence-guided resection had been discovered, opening the door for photodynamic approaches for the treatment of brain cancer. Thermal laser application in the nasal cavity obtained clinical acceptance by the introduction of new laser wavelengths in clinical consciousness. Varicose veins can be treated by innovative endoluminal treatment methods, thus reducing side effects and saving time. Techniques and developments are presented with potential for diagnosis and treatment to improve the clinical situation for the benefit of the patient.

  3. Tailored Ceramics for Laser Applications

    SciTech Connect

    Hollingsworth, Joel

    2007-12-10

    Transparent ceramics match or exceed the performance of single-crystal materials in laser applications, with a more-robust fabrication process. Controlling the distribution of optical dopants in transparent ceramics would allow qualitative improvements in amplifier slab design by allowing gain and loss to be varied within the material. My work aims to achieve a controlled pattern or gradient of dopant prior to sintering, in order to produce tailored ceramics.

  4. Catadioptric Optics for laser Doppler velocimeter applications

    NASA Technical Reports Server (NTRS)

    Dunagan, Stephen E.

    1989-01-01

    In the design of a laser velocimeter system, attention must be given to the performance of the optical elements in their two principal tasks: focusing laser radiation into the probe volume, and collecting the scattered light. For large aperture applications, custom lens design and fabrication costs, long optical path requirements, and chromatic aberration (for two color operation) can be problematic. The adaptation of low cost Schmidt-Cassegrain astronomical telescopes to perform these laser beam manipulation and scattered light collection tasks is examined. A generic telescope design is analyzed using ray tracing and Gaussian beam propagation theory, and a simple modification procedure for converting from infinite to near unity conjugate ratio operation with image quality near the diffraction limit was identified. Modification requirements and performance are predicted for a range of geometries. Finally, a 200-mm-aperture telescope was modified for f/10 operation; performance data for this modified optic for both laser beam focusing and scattered light collection tasks agree well with predictions.

  5. Laser applications in endodontics: an update review.

    PubMed

    Mohammadi, Zahed

    2009-02-01

    The search for new devices and technologies for endodontic procedures always has been challenging. Since the development of the ruby laser by Maiman in 1960 and the application of the laser for endodontics by Weichman in 1971, a variety of potential applications for lasers in endodontics have been proposed. With the development of thinner, more flexible and durable laser fibres, laser applications in endodontics have increased. Since laser devices are still relatively costly, access to them is limited. The purpose of this paper is to summarise laser applications in endodontics, including their use in pulp diagnosis, dentinal hypersensitivity, pulp capping and pulpotomy, sterilisation of root canals, root canal shaping and obturation and apicectomy. The effects of lasers on root canal walls and periodontal tissues are also reviewed. PMID:19323310

  6. Laser ignition application in a space experiment

    NASA Technical Reports Server (NTRS)

    Liou, Larry C.; Culley, Dennis E.

    1993-01-01

    A laser ignition system is proposed for the Combustion Experiment Module on an orbiting spacecraft. The results of a design study are given using the scheduled 'Flame Ball Experiment' as the design guidelines. Three laser ignition mechanisms and wavelengths are evaluated. A prototype laser is chosen and its specifications are given, followed by consideration of the beam optical arrangement, the ignition power requirement, the laser ignition system weight, size, reliability, and laser cooling and power consumption. Electromagnetic interference to the onboard electronics caused by the laser ignition process is discussed. Finally, ground tests are suggested.

  7. Lasers.

    ERIC Educational Resources Information Center

    Schewe, Phillip F.

    1981-01-01

    Examines the nature of laser light. Topics include: (1) production and characteristics of laser light; (2) nine types of lasers; (3) five laser techniques including holography; (4) laser spectroscopy; and (5) laser fusion and other applications. (SK)

  8. Applications of soft x-ray lasers

    SciTech Connect

    Skinner, C.H.

    1993-08-01

    The high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. Imaging of biological specimens using x-ray lasers has been demonstrated by several groups. Other applications to fields such as chemistry, material science, plasma diagnostics, and lithography are beginning to emerge. We review the current status of soft x-ray lasers from the perspective of applications, and present an overview of the applications currently being developed.

  9. Applications analysis of high energy lasers

    NASA Technical Reports Server (NTRS)

    Arno, R. D.; Mackay, J. S.; Nishioka, K.

    1972-01-01

    An analysis and comparison of laser technology with competing technologies were made to determine possible laser applications. The analysis was undertaken as follows: (1) possible applications were listed and categorized; (2) required components were enumerated and the characteristics of these components were extrapolated; (3) complete system characteristics were calculated parametrically for selected applications using the postulated component characteristics; and (4) where possible and appropriate, comparisons were made with competing systems. It was found that any large scale replacement of existing systems and methods by lasers requires many technological advances in laser and associated systems. However, several applications appear feasible, such as low orbit drag make-up, orbit changing, communications, and illumination applications.

  10. FY 2005 Quantum Cascade Laser Alignment System Final Report

    SciTech Connect

    Myers, Tanya L.; Cannon, Bret D.; Wojcik, Michael D.; Broocks, Bryan T.; Stewart, Timothy L.; Hatchell, Brian K.

    2006-01-11

    The Alignment Lasers Task of Pacific Northwest National Laboratory's (PNNL's) Remote Spectroscopy Project (Project PL211I) is a co-funded project between DOE NA-22 and a Classified Client. This project, which began in the second half of FY03, involved building and delivering a Quantum Cascade (QC) Laser Alignment System to be used for testing the pupil alignment of an infrared sensor by measuring the response from four pairs of diametrically opposed QC lasers. PNNL delivered the system in FY04 and provided technical assistance in FY05 culminating into a successful demonstration of the system. This project evolved from the Laser Development Task of PL211I, which is involved in developing novel laser technology to support development of advanced chemical sensors for detecting the proliferation of nuclear weapons. The laser systems are based on quantum cascade (QC) lasers, a new semiconductor source in the infrared. QC lasers can be tailored to emit light throughout the infrared region (3.5 ? 17 ?m) and have high output power and stability. Thus, these lasers provide an infrared source with superb power and spectral stability enabling them to be used for applications such as alignment and calibration in addition to chemical sensing.

  11. Industrial application of high power disk lasers

    NASA Astrophysics Data System (ADS)

    Brockmann, Rüdiger; Havrilla, David

    2008-02-01

    Laser welding has become one of the fastest growing areas for industrial laser applications. The increasing cost effectiveness of the laser process is enabled by the development of new highly efficient laser sources, such as the Disk laser, coupled with decreasing cost per Watt. TRUMPF introduced the Disk laser several years ago, and today it has become the most reliable laser tool on the market. The excellent beam quality and output powers of up to 10 kW enable its application in the automotive industry as well as in the range of thick plate welding, such as heavy construction and ship building. This serves as an overview of the most recent developments on the TRUMPF Disk laser and its industrial applications like cutting, welding, remote welding and hybrid welding, too. The future prospects regarding increased power and even further improved productivity and economics are presented.

  12. Liquid crystals for laser applications

    NASA Astrophysics Data System (ADS)

    Jacobs, S. D.; Marshall, K. L.; Schmid, A.

    1992-10-01

    This article highlights some of the advances made in the use of liquid crystals for laser applications from 1982 through 1992. New materials and new effects were discovered, many new devices were developed, and novel applications for well-understood phenomena were conceived. This was quite an eventful time period. Several new books were published on the broad subject of LC's, and the international scientific community organized a society devoted to encouraging further scientific and educational advancement in the field. Attention was focused on LC's in October of 1991 when the Nobel Prize in Physics was awarded to Pierre-Gilles de Gennes for his pioneering work toward understanding order phenomena in LC's and polymers. This article is divided into four sections. The first section discusses new materials, specifically ferroelectric LC's and LC polymers. The former have opened up the realm of submicrosecond response for LC devices, and the latter have significantly reduced the sensitivity of LC optics to temperature. Some new insights into the optical properties of materials are also mentioned. The second section reviews new developments in passive applications for cholesterics and nematics. Included here are the fabrication of cholesteric laser mirrors and apodizers, the use of LC polymers for notch filters and as optical storage media, and some novel nematic retarder concepts such as the distributed polarization rotator.

  13. Current new applications of laser plasmas

    SciTech Connect

    Hauer, A.A.; Forslund, D.W.; McKinstrie, C.J.; Wark, J.S.; Hargis, P.J. Jr.; Hamil, R.A.; Kindel, J.M.

    1988-09-01

    This report describes several new applications of laser-produced plasmas that have arisen in the last few years. Most of the applications have been an outgrowth of the active research in laser/matter interaction inspired by the pursuit of laser fusion. Unusual characteristics of high-intensity laser/matter interaction, such as intense x-ray and particle emission, were noticed early in the field and are now being employed in a significant variety of applications outside the fusion filed. Applications range from biology to materials science to pulsed-power control and particle accelerators. 92 refs., 23 figs., 4 tabs.

  14. Application of laser in obstetrics and gynecology

    NASA Astrophysics Data System (ADS)

    Ding, Ai-Hua

    1998-11-01

    Mainman developed the first ruby laser in 1960 and after 13 Kaplan successfully reported the use of CO2 laser in the treatment of cervicitis. Soon after, Chinese gynecologists started to use the laser for diagnosis and therapy. It had been proved that more than 30 kinds of gynecological diseases could be treated effectively by laser. The remarkable laser treatment technique partially replaced with conventional methods used in that century. However, the application of laser had shown a broad prospect along with its further investigation.

  15. Laser technology and applications in gynaecology.

    PubMed

    Adelman, M R; Tsai, L J; Tangchitnob, E P; Kahn, B S

    2013-04-01

    The term 'laser' is an acronym for Light Amplification by Stimulated Emission of Radiation. Lasers are commonly described by the emitted wavelength, which determines the colour of the light, as well as the active lasing medium. Currently, over 40 types of lasers have been developed with a wide range of both industrial and medical uses. Gas and solid-state lasers are frequently used in surgical applications, with CO2 and Ar being the most common examples of gas lasers, and the Nd:YAG and KTP:YAG being the most common examples of solid-state lasers. At present, it appears that the CO2, Nd:YAG, and KTP lasers provide alternative methods for achieving similar results, as opposed to superior results, when compared with traditional endoscopic techniques, such as cold-cutting monopolar and bipolar energy. This review focuses on the physics, tissue interaction, safety and applications of commonly used lasers in gynaecological surgery.

  16. Laser micromachining: new developments and applications

    NASA Astrophysics Data System (ADS)

    Rizvi, Nadeem H.; Milne, David K.; Rumsby, Phil T.; Gower, Malcolm C.

    2000-06-01

    Excimer laser micromachining has developed into a mature production method and many industrial applications such as the drilling of ink-jet printer nozzles, production environments. The important concepts of excimer laser micromachining systems are described and the novel methods which have been developed in this area are presented. In particular, techniques for the production of complex, multi- level 3D microstructures are described and examples of such features are used to illustrate the relevant applications. Furthermore, some initial micromachining result from a sub- nanosecond, solid-state fiber laser are presented to highlight the rapidly-growing area of laser micro processing using ultra-short pulse lasers.

  17. The Final Focus Test Beam laser referene system

    SciTech Connect

    Bressler, V.E.; Ruland, R.E.

    1993-05-01

    The original design for the SLAC linac included an alignment reference system with 270 diffraction gratings situated along the 3000 meter linac. These gratings have provided SLAC with a global reference line repeatable to within 200 micro meters. For the Final Focus Test Beam, this laser system has been extended and 13 new diffraction gratings have been installed. Improvements targets and the availability of new instruments allows us to evaluate the performance of the laser reference system at the 510 micro meter level. An explanation of the system and the results of our evaluation are presented.

  18. Power plant material characterization by lasers. Final report

    SciTech Connect

    Not Available

    1993-02-01

    The EPRI Nuclear Division undertook examination of the feasibility of utilizing lasers to perform in situ operations within power plants in 1983. The Nd- Yag laser was of particular interest because flexible fiber optics cabling could be utilized for beam transport; the end effectors could be made small enough to access power plant components remotely. Beam management for welding and metal conditioning in confined spaces; the first issue examined, lead to the application for steam generator repairs that is now in common usage. This report examines the laser beam as a source of information about the material property condition; an application made feasible by advances in fiber and laser technology that were achieved beginning in 1989. This work, examines the prospects for determination of material condition properties within power plants because the laser beam can be utilized for sampling and as a source of optical, thermal, ultrasonic, spectrographic and mensuration data that may be obtained nondestructively. Both application evaluations and feasibility testing is described.

  19. Cascade laser applications: trends and challenges

    NASA Astrophysics Data System (ADS)

    d'Humières, B.; Margoto, Éric; Fazilleau, Yves

    2016-03-01

    When analyses need rapid measurements, cost effective monitoring and miniaturization, tunable semiconductor lasers can be very good sources. Indeed, applications like on-field environmental gas analysis or in-line industrial process control are becoming available thanks to the advantage of tunable semiconductor lasers. Advances in cascade lasers (CL) are revolutionizing Mid-IR spectroscopy with two alternatives: interband cascade lasers (ICL) in the 3-6μm spectrum and quantum cascade lasers (QCL), with more power from 3 to 300μm. The market is getting mature with strong players for driving applications like industry, environment, life science or transports. CL are not the only Mid-IR laser source. In fact, a strong competition is now taking place with other technologies like: OPO, VCSEL, Solid State lasers, Gas, SC Infrared or fiber lasers. In other words, CL have to conquer a share of the Mid-IR application market. Our study is a market analysis of CL technologies and their applications. It shows that improvements of components performance, along with the progress of infrared laser spectroscopy will drive the CL market growth. We compare CL technologies with other Mid-IR sources and estimate their share in each application market.

  20. Safe laser application requires more than laser safety

    NASA Astrophysics Data System (ADS)

    Frevel, A.; Steffensen, B.; Vassie, L.

    1995-02-01

    An overview is presented concerning aspects of laser safety in European industrial laser use. Surveys indicate that there is a large variation in the safety strategies amongst industrial laser users. Some key problem areas are highlighted. Emission of hazardous substances is a major problem for users of laser material processing systems where the majority of the particulate is of a sub-micrometre size, presenting a respiratory hazard. Studies show that in many cases emissions are not frequently monitored in factories and uncertainty exists over the hazards. Operators of laser machines do not receive adequate job training or safety training. The problem is compounded by a plethora of regulations and standards which are difficult to interpret and implement, and inspectors who are not conversant with the technology or the issues. A case is demonstrated for a more integrated approach to laser safety, taking into account the development of laser applications, organizational and personnel development, in addition to environmental and occupational health and safety aspects. It is necessary to achieve a harmonization between these elements in any organization involved in laser technology. This might be achieved through establishing technology transfer centres in laser technology.

  1. Surgical application of lasers. 2nd edition

    SciTech Connect

    Dixon, J.A.

    1987-01-01

    Lasers have been successfully used in several new clinical areas such as cardiovascular, orthopedic, and pulmonary surgery as well as in specialties covered in the first edition including otorhinolaryngology, dermatology and plastic surgery, gastroenterology, and urology. These advances are all discussed in this text. Introductory chapters cover the background of laser surgery, techniques and instrumentation and safety procedures. The remaining chapters cover lasers in specific fields such as endoscopic surgery, gynecology, neurosurgery and many more. The final chapters provide an overview of photodynamic therapy and the future of laser surgery.

  2. Fiber lasers and their applications [Invited].

    PubMed

    Shi, Wei; Fang, Qiang; Zhu, Xiushan; Norwood, R A; Peyghambarian, N

    2014-10-01

    Fiber lasers have seen progressive developments in terms of spectral coverage and linewidth, output power, pulse energy, and ultrashort pulse width since the first demonstration of a glass fiber laser in 1964. Their applications have extended into a variety of fields accordingly. In this paper, the milestones of glass fiber laser development are briefly reviewed and recent advances of high-power continuous wave, Q-switched, mode-locked, and single-frequency fiber lasers in the 1, 1.5, 2, and 3 μm regions and their applications in such areas as industry, medicine, research, defense, and security are addressed in detail.

  3. (CO/sub 2/ TEA laser development). Final report

    SciTech Connect

    Gundersen, M.

    1980-10-01

    The Texas Tech research program has developed a laser system suitable for programs requiring lasers with high spectral brightness. Such applications include high repetition rate, high power process lasers, but the system is also suitable for high resolution spectroscopy. A general technique for obtaining tunable single longitudinal mode (SLM) operation of a CO/sub 2/ TEA laser has been demonstrated using intracavity selective absorbers. Briefly the selective absorber produces SLM operation by shifting the maximal net loop gain from the CO/sub 2/ line center to a transmission peak of the selective absorber. The exact frequency selected is determined by a convolution of the CO/sub 2/ gain curve, transmission characteristics of the selective absorber and the laser cavity modes. The method is of interest because it is simple and inexpensive, suitable for high energy and high repetition rate systems, and has the advantage for certain applications of locking the SLM output to a molecular absorption feature - rather than a temperature or vibration sensitive cavity element.

  4. Laser Scanning Applications in Fluvial Geomorphology

    NASA Astrophysics Data System (ADS)

    Alho, P.

    2014-12-01

    During recent decades, the use of high-resolution laser scanning data in fluvial studies has rapidly increased. Airborne laser scanning (ALS) can be used to extensively map riverine topography. Laser scanning data have great potential to improve the effectiveness of topographical data acquisition and the accuracy and resolution of DTMs (Digital Terrain Models) needed in fluvial geomorphology. Airborne Laser Scanning (ALS) is applicable for mapping areas varying from reach to catchment scale and these data are, therefore, particularly suitable, especially for hydraulic modelling, mapping of flood inundation, and the detection of macro-scale fluvial geomorphology. With Terrestrial Laser Scanning (TLS) a spatial resolution of less than 1 mm and a range accuracy of few millimetres can be achieved. Mobile Laser Scanning (MLS) enables a remarkably faster survey approach compared to the conventional TLS method. One of the newest applications of MLS approaches involves a boat/cart/backpack -based mobile mapping system. This set-up includes laser scanning and imaging from a platform moving along a river course or floodplain and may be used to expand the spatial extent of terrestrial scanning. Detailed DTMs derived from laser scanning data can be used to improve the recognition of fluvial landforms, the geometric data of hydraulic modelling, and the estimation of flood inundation extents and the associated fluvial processes. Fluvial environments also offer challenges for the application of laser scanning techniques. Factors such as vegetation cover, terrain undulation, coarse surface materials and water surfaces may distort a laser scanning survey.

  5. Laser safety aspects for medical applications

    NASA Astrophysics Data System (ADS)

    Gabay, Shimon

    2003-12-01

    Most applications of lasers in medicine are based on the producing of a controlled thermal damage into a preferably tissue location. Laser safety deals with non controlled damage (thermal or other) that could be randomly produced into a non preferable tissue locations. This kind of damage is not allowed and the laser safety material is designed to provide the user with a knowledge and with sufficient safety instructions and means to prevent such damage. Following the laser safety instructions is especially important for the medical applications because in these applications the laser beam is brought in a close proximity to the patient's body and non-desired damage can be easily produced. Most medical lasers are classified as Class 4 laser products, the highest hazard class. Direct laser beam of class 4 is capable to produce skin burns and to ignite flammable materials, and even its scattered beam may produce severe eye damage. The paper presents the nature of the skin and eye damage for different spectral range, and the state of the art rules in preventing such damage. The safety means that should be implemented in, and around, the laser clinique and in the laser surgery room will also be highlighted.

  6. Current status of laser applications in urology

    NASA Astrophysics Data System (ADS)

    Knipper, Ansgar; Thomas, Stephen; Durek, C.; Jocham, Dieter

    1993-05-01

    The overall development of laser use in urology is recessing. The reasons are the refinement of methods of radical surgery and the continuing development of alternative technologies involving electric current. Taking the cost factor into account, are lasers still opportune in medicine? The answer is definitely yes. Cost reduction in medical practice without quality loss is only possible with effective methods of minimally invasive surgery. Continuing investigation of cutting, welding, coagulating and ablating instruments is justified. Competition of lasers to other technologies can only be beneficial to the cause. But where are the highlights of laser applications? The unsurpassed utilization of optical properties of lasers lie in the concept of photodynamic therapies and in optical feedback mechanisms for laser applications. The combination of lasers with three dimensional visualization of the treatment area by ultrasound (TULIP-procedure for benign prostatic hyperplasia) is a novel approach in laser application. The further development of these treatment modalities will reveal the true benefit of laser technology in urological applications.

  7. Pathophysiological aspects of laser application

    NASA Astrophysics Data System (ADS)

    Egorova, Alla B.; Stavitskaya, Ekaterina Y.; Salmin, Vladimir V.; Fedyukovich, Lyudmila V.; Mikhutkina, S. V.; Shapran, M. V.; Ivanov, V. V.; Provorov, Alexander S.

    1996-04-01

    The rapid growth of electrooptics and laser technology has increased the possibility of human exposure to optical radiation and concern about health effects. The much attention has to be focused on the creation of the safety program that assures the safe use of lasers taking into account the possible side effects of laser therapy. In order to investigate the imunotropic effect of lasers the experimental model which was close to the therapeutic modes has been used for IR laser (the wavelength 890 nm) and He-Ne laser (the wavelength 633 nm). The immune system underwent changes testifying about the breaches in the processes of maturation and migration of the lymphoid cells, also the alteration of receptors as a sign of the membrane damaging effect of lasers was seen.

  8. Deformable mirror for high power laser applications

    NASA Astrophysics Data System (ADS)

    Mrň; a, Libor; Sarbort, Martin; Hola, Miroslava

    2015-01-01

    The modern trend in high power laser applications such as welding, cutting and surface hardening lies in the use of solid-state lasers. The output beam of these lasers is characterized by a Gaussian intensity distribution. However, the laser beams with different intensity distributions, e.g. top-hat, are preferable in various applications. In this paper we present a new type of deformable mirror suitable for the corresponding laser beam shaping. The deformation of the mirror is achieved by an underlying array of actuators and a pressurized coolant that also provides the necessary cooling. We describe the results of the surface shape measurement using a 3D scanner for different settings of actuators. Further, we show the achieved intensity distributions measured by a beam profiler for a low power laser beam reflected from the mirror.

  9. Fiber optic applications for laser polarized targets

    SciTech Connect

    Cummings, W.J.; Kowalczyk, R.S.

    1997-10-01

    For the past two years, the laser polarized target group at Argonne has been used multi-mode fiber optic patch cords for a variety of applications. In this paper, the authors describe the design for transporting high power laser beams with optical fibers currently in use at IUCF.

  10. Research on laser damage of final optics assembly on high-power laser facility

    NASA Astrophysics Data System (ADS)

    Zhao, Dongfeng; Wu, Rong; Lin, Zunqi; Zhu, Jianqiang; Wang, Li

    2014-10-01

    In order to improve laser damage resistance of the Final Optics Assembly (FOA), simulation analysis have been done for 1ω, 2ω and 3ω laser beam considering ghost images to the 4th order. The panels of ground glass scatter ghost laser around the FOA walls and the panels of architectural glass absorb the 1th order energy. The appearance of smoothing fused silica surface defect and the effect of wiping off etching contamination are researched on HF-based etching processes under ultrasonic. Now, 18 shots were executed using 310x310mm laser with 3ns pulse width. During the experiment, the third harmonic laser terminal output energy is 1500J~3500J, and the maximum laser energy flux is about 4J/cm2. This presentation addresses the optical configuration of the FOA, the simulation analysis of ghost, the way of ground glasses absorbing energy and the result of laser damage resistance of fused silica on HF-based etching processes under ultrasonic.

  11. Physics and applications of laser diode chaos

    NASA Astrophysics Data System (ADS)

    Sciamanna, M.; Shore, K. A.

    2015-03-01

    This Review Article provides an overview of chaos in laser diodes by surveying experimental achievements in the area and explaining the theory behind the phenomenon. The fundamental physics underpinning laser diode chaos and also the opportunities for harnessing it for potential applications are discussed. The availability and ease of operation of laser diodes, in a wide range of configurations, make them a convenient testbed for exploring basic aspects of nonlinear and chaotic dynamics. It also makes them attractive for practical tasks, such as chaos-based secure communications and random number generation. Avenues for future research and development of chaotic laser diodes are also identified.

  12. Alkali metal vapors - Laser spectroscopy and applications

    NASA Technical Reports Server (NTRS)

    Stwalley, W. C.; Koch, M. E.

    1980-01-01

    The paper examines the rapidly expanding use of lasers for spectroscopic studies of alkali metal vapors. Since the alkali metals (lithium, sodium, potassium, rubidium and cesium) are theoretically simple ('visible hydrogen'), readily ionized, and strongly interacting with laser light, they represent ideal systems for quantitative understanding of microscopic interconversion mechanisms between photon (e.g., solar or laser), chemical, electrical and thermal energy. The possible implications of such understanding for a wide variety of practical applications (sodium lamps, thermionic converters, magnetohydrodynamic devices, new lasers, 'lithium waterfall' inertial confinement fusion reactors, etc.) are also discussed.

  13. Industrial applications of laser neutron source

    NASA Astrophysics Data System (ADS)

    Nakai, S.; Mima, K.; Kato, Y.; Tanaka, K.; Ikeda, Y.; Azechi, H.; Miyanaga, K.; Nakai, M.; Perlado, M.; Gonzalez Arrabal, R.

    2010-08-01

    The industrial applications of the intense neutron source have been widely explored because of the unique features of the neutron-matter interaction. Usually, intense neutron sources are assembled with fission reactors or high energy ion accelerators. The big size and high cost of these systems are the bottle neck to promote the industrial applications of intense neutrons. In this paper, we propose the compact laser driven neutron source for the industrial application. As the first step of our project for the versatile applications of laser driven neutron source, Li-neutron and/or Li-proton interactions have been investigated for the application to the development of Li battery.

  14. Medical applications of ultra-short pulse lasers

    SciTech Connect

    Kim, B M; Marion, J E

    1999-06-08

    The medical applications for ultra short pulse lasers (USPLs) and their associated commercial potential are reviewed. Short pulse lasers offer the surgeon the possibility of precision cutting or disruption of tissue with virtually no thermal or mechanical damage to the surrounding areas. Therefore the USPL offers potential improvement to numerous existing medical procedures. Secondly, when USPLs are combined with advanced tissue diagnostics, there are possibilities for tissue-selective precision ablation that may allow for new surgeries that cannot at present be performed. Here we briefly review the advantages of short pulse lasers, examine the potential markets both from an investment community perspective, and from the view. of the technology provider. Finally nominal performance and cost requirements for the lasers, delivery systems and diagnostics and the present state of development will be addressed.

  15. Laser-based nanoengineering of surface topographies for biomedical applications

    NASA Astrophysics Data System (ADS)

    Schlie, Sabrina; Fadeeva, Elena; Koroleva, Anastasia; Ovsianikov, Aleksandr; Koch, Jürgen; Ngezahayo, Anaclet; Chichkov, Boris. N.

    2011-04-01

    In this study femtosecond laser systems were used for nanoengineering of special surface topographies in silicon and titanium. Besides the control of feature sizes, we demonstrated that laser structuring caused changes in material wettability due to a reduced surface contact area. These laser-engineered topographies were tested for their capability to control cellular behavior of human fibroblasts, SH-SY5Y neuroblastoma cells, and MG-63 osteoblasts. We found that fibroblasts reduced cell growth on the structures, while the other cell types proliferated at the same rate. These findings make laser-surface structuring very attractive for biomedical applications. Finally, to explain the results the correlation between topography and the biophysics of cellular adhesion, which is the key step of selective cell control, is discussed.

  16. Laser power beaming for satellite applications

    SciTech Connect

    Friedman, H.W.

    1993-09-22

    A serious consideration of laser power beaming for satellite applications appears to have grown out of a NASA mission analysis for transmitting power to lunar bases during the two week dark period. System analyses showed that laser power beaming to the moon in conjunction with efficient, large area solar cell collection panels, were an attractive alternative to other schemes such as battery storage and nuclear generators, largely because of the high space transportation costs. The primary difficulty with this scheme is the need for very high average power visible lasers. One system study indicated that lasers in excess of 10 MW at a wavelength of approximately 850 nm were required. Although such lasers systems have received much attention for military applications, their realization is still a long term goal.

  17. Lasers and their therapeutic application in chiropractic

    PubMed Central

    Fitz-Ritson, Don

    2001-01-01

    The purpose of this paper is to review some of the applications of laser therapy and its reported effects on tissue healing, pain relief and other effects. Several musculoskeletal and low back pain studies are highlighted to show the efficacy of laser therapy and its' applicability as an adjunct to chiropractic treatment. Information is also presented which highlights the necessary information the clinician should be aware of in order to develop specific protocols for musculoskeletal pathologies. The parameters, which are now available on lasers, include power, frequency, duty cycle and cadence. When these are manipulated, different effects are achieved on tissues, which may enhance chiropractic treatment. Imagesp34-a

  18. Soft x-ray laser microscope. Final report

    SciTech Connect

    Suckewer, P.I.

    1990-10-01

    The program consisted of two phases (Phase I and Phase II). The goal of the Phase I (first year program) was to design and construct the Soft X-ray Laser Contact Microscope. Such microscope was constructed and adapted to PPL`s 18.2nm soft X-ray Laser (SXL), which in turn was modified and prepared for microscopy experiments. Investigation of the photoresist response to 18.2nm laser radiation and transmissivity of 0.1m thick silicion-nitride (Si{sub 3}N{sub 4}) windows were important initial works. The goal of the first year of Phase II was to construct X-ray contact microscope in combination with existing optical phase microscope, already used by biologists. In the second year of Phase II study of dehydrated Horeseshoe Crab and Hela cancer cells were performed with COXRALM. Also during Phase II, the Imaging X-Ray Laser Microscope (IXRALM) was designed and constructed. This paper describes the development of each of the microscopes and their application for research.

  19. Military applications of the laser weapons in the future battlefield

    NASA Astrophysics Data System (ADS)

    Celik, Hasan; Adana, Saban; Yahsi, Erhan

    2013-05-01

    Contemporary operating environment requires a wide range of tools to respond to a myriad of regular and irregular threats. Accordingly, conventional weapons do not suffice in some cases. As technology improves exponentially, the dominance of conventional weapons is slowly fading away by the advances in laser technology. This study first outlines the characteristics of laser weapons, then provides the military applications of them in land, maritime, air and space domains and finally exhibits implications for battlefield functions. This study concludes that any country that is seeking primacy in military terms must allocate extra time and resources to obtain this emerging technology. Since it seems that there are not adequate studies about the military applications and operational concepts of the laser weapons, this study tries to increase awareness about their potential advantages.

  20. Laser-induced breakdown spectroscopy expands into industrial applications

    NASA Astrophysics Data System (ADS)

    Noll, Reinhard; Fricke-Begemann, Cord; Brunk, Markus; Connemann, Sven; Meinhardt, Christoph; Scharun, Michael; Sturm, Volker; Makowe, Joachim; Gehlen, Christoph

    This paper presents R&D activities in the field of laser-induced breakdown spectroscopy for industrial applications and shows novel LIBS systems running in routine operation for inline process control tasks. Starting with a comparison of the typical characteristics of LIBS with XRF and spark-discharge optical emission spectrometry, the principal structure of LIBS machines embedded for inline process monitoring will be presented. A systematic requirement analysis for LIBS systems following Ishikawa's scheme was worked out. Stability issues are studied for laser sources and Paschen-Runge spectrometers as key components for industrial LIBS systems. Examples of industrial applications range from handheld LIBS systems using a fiber laser source, via a set of LIBS machines for inline process control tasks, such as scrap analysis, coal analysis, liquid slag analysis and finally monitoring of drill dust.

  1. Advanced tunable laser source for DoD applications

    SciTech Connect

    Cockroft, N.; Early, J.; Johnson, C.; Lester, C.; Quick, C.; Shimada, T.; Tiee, J.

    1996-06-01

    This is a final report of a two year project at the Los Alamos National Laboratory (LANL). The project sought to develop a new solid- state laser transmitter that can be tuned over an exceptionally broad spectral range and integrated with LIDAR remote sensing systems for applications in species specific chemical sensing. Activities have included non-linear frequency conversion of tunable chromium doped LiSAF laser radiation to the ultraviolet and infrared spectral regions. This system is capable of the detection of chemical species previously unapproachable, as well as an improvement in detection sensitivity of 1-2 orders of magnitude for species currently studied.

  2. Laser application for hypertrophic rhinitis

    NASA Astrophysics Data System (ADS)

    Inouye, Tetsuzo; Tanabe, Tetsuya; Nakanoboh, Manabu; Ogura, Masami

    1995-05-01

    The CO2 and KTP/532 lasers have been used in the treatment of an allergic and hypertrophic rhinitis for the past several years. As we know, the laser enables a surgeon to perform the operation with minimum hemorrhage and minimized pain, during and after the procedure. Additionally many of these operations can be performed under local anesthesia instead of general anesthesia, on an outpatient basis. The laser is used to irradiate the mucous membranes of the inferior turbinates. Vaporization and cutting is easily done. Post operative management of the local operated area is easy. The advantages of laser surgery over regular surgical techniques are supreme for intranasal operations when performed under local anesthesia.

  3. Biomedical applications of laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Svanberg, Sune

    1999-07-01

    Very soon after the invention of the laser, the use of the thermal effects of the radiation was introduced. Such techniques have been refined and the laser is now routinely used for treatment in many specialities. Photodynamic therapy (PDT) is a non-thermal modality employing the combination of a tumor-seeking agent and activating laser light. During the last 15 years laser spectroscopic techniques have also been developed providing powerful means for non-intrusive medical diagnostics of tissue in real time. At the beginning only few groups were involved in exploratory work, but successively the field has developed now to occupy a large number of research teams, which meet at large specialized conferences. We will here consider three aspects of laser diagnostics: fluorescence, Raman and near-IR, and elastic scattering spectroscopy, and we will also briefly discuss PDT. The activity in the field is very extensive, and rather than trying to give a full overview, illustrations from work performed at the Lund University Medical Laser Center will be given.

  4. Science and Math Applications. Final Report.

    ERIC Educational Resources Information Center

    Lauver, Lori A.

    This document includes a final report and curriculum guide from a project to develop a Science and Math Applications curriculum that related science and math to everyday life and promoted confidence in adult basic education students in their science and math skills. The report describes how the curriculum used traditional teaching methods to teach…

  5. Applications of laser annealing and laser-induced diffusion to photovoltaic conversion

    SciTech Connect

    Lowndes, D.H.; Young, R.T.; Wood, R.F.

    1981-01-01

    Over the past several years it has been demonstrated that a variety of techniques involving pulsed laser irradiation of both single crystal and polycrystalline silicon by pulsed lasers can result in the reproducible achievement of high efficiency silicon solar cells. Pulsed laser annealing (PLA) after an ion implantation (II) step results in melting (for a time of order 100 nsec) and essentially defect-free liquid phase epitaxial regrowth within approx. 0.5 ..mu..m of the surface. Complete electrical activation of a number of dopant ions, at concentrations exceeding ordinary solubility limits, has been demonstrated and crystalline (polycrystalline) silicon solar cell efficiencies of 16.6% (12.5%) have been obtained. Other p-n junction and solar cell fabrication techniques have been demonstrated. Pulsed laser processing has also been demonstrated to have several other unique and beneficial advantages in polycrystalline silicon substrates. For example, grain boundaries do not exist during laser melting, while dopant diffusion is taking place; the short melt durations involved further limit dopant diffusion; precipitates present after conventional high temperature dopant diffusion can be removed; and, certain types of electrically active grain boundaries can be made inactive by pulsed laser irradiation. Finally, grain growth in fine-grained polycrystalline silicon films, via pulsed laser melting and recrystallization, has been demonstrated. Because little is known about the application of similar pulsed laser processing techniques to compound semiconductors, particularly in connection with the formation of shallow p-n junctions, research has been devoted to studies of pulsed laser processing of GaAs and compound semiconductor solar cell fabrication techniques that are compatible with the use of pulsed lasers. Progress is reported. (WHK)

  6. Laser applications in pediatric airway surgery

    NASA Astrophysics Data System (ADS)

    Karamzadeh, Amir M.; Ahuja, Gurpreet S.; Nguyen, John D.; Crumley, Roger

    2003-06-01

    The smaller anatomy and limited access to instrumentation pose a challenge to the pediatric airway surgeon. The enhanced precision and ability to photocoagulate tissue while operating with the laser enhances the surgeon"s ability to successfully treat unique pediatric conditions such subglottic hemangiomas, congenital cysts, respiratory papillomatosis, and laryngeal or tracheal stenosis. Due to its shallow tissue penetration and thermal effect, the carbon dioxide (CO2) laser is generally considered the laser of choice for pediatric airway applications. The potential for increased scarring and damage to underlying tissue caused by the greater penetration depth and thermal effect of the Nd:YAG and KTP lasers preclude their use in this population. In this review, we will describe the specific advantages of using lasers in airway surgery, the current technology and where the current technology is deficient.

  7. Metal Vapour Lasers: Physics, Engineering and Applications

    NASA Astrophysics Data System (ADS)

    Little, Christopher E.

    1999-03-01

    Metal Vapour Lasers Christopher E. Little University of St Andrews, St Andrews, Scotland Since the first successful demonstration of a metal vapour laser (MVL) in 1962, this class of laser has become widely used in a broad range of fields including precision materials processing, isotope separation and medicine. The MVLs that are used today have a range of impressive characteristics that are not readily available using other technologies. In particular, the combination of high average output powers, pulse recurrence frequencies and beam quality available from green/yellow Cu vapour lasers (CVLs) and Cu bromide lasers, coupled with the high-quality, multiwatt ultraviolet (265-289 nm) radiation that can be produced using simple nonlinear optical techniques, means that Cu lasers will continue to be important for many years. Metal Vapour Lasers covers all the most commercially important and scientifically interesting pulsed and continuous wave (CW) gas-discharge MVLs, and includes device histories, operating characteristics, engineering, kinetics, commercial exploitation and applications. Short descriptions of gas discharges and excitation techniques make this volume self-consistent. A comprehensive bibliography is also provided. The greater part of this book is devoted to CVLs and their variants, including new sealed-off, high-power 'kinetically enhanced' CVLs and Cu bromide lasers. However, many other self-terminating MVLs are also discussed, including the red AuVL, green/infrared MnVL and infrared BaVL. Pulsed, high-gain, high average power lasers in the UV/violet (373.7, 430.5 nm) spectral regions are represented by Sr¯+ and Ca¯+ discharge-afterglow recombination lasers. The most commercially successful of the MVLs - the CW, UV/blue cataphoretic He-Cd¯+ ion laser - is described. Hollow cathode lasers are represented in two guises: 'white light' (blue/green/red) He-Cd¯+ ion lasers and UV/infrared Ne/He-Cu¯+ ion lasers. This unique volume is an

  8. Space Applications Industrial Laser System (SAILS)

    NASA Technical Reports Server (NTRS)

    Mccay, T. D.; Bible, J. B.; Mueller, R. E.

    1993-01-01

    A program is underway to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. This workstation, called Space Applications Industrial Laser System (SAILS), will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use in constructing the Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1996, will be constructed as three modules using standard Get-Away-Special (GAS) canisters. The first module holds the laser head and cooling system, while the second contains a high peak power electrical supply. The third module houses the materials processing workstation and the command and data acquisition subsystems. The laser head and workstation cansisters are linked by a fiber-optic cable to transmit the laser light. The team assembled to carry out this project includes Lumonics Industrial Products (laser), Tennessee Technological University (structural analysis and fabrication), Auburn University Center for Space Power (electrical engineering), University of Waterloo (low-g laser process consulting), and CSTAR/UTSI (data acquisition, control, software, integration, experiment design). This report describes the SAILS program and highlights recent activities undertaken at CSTAR.

  9. Supercontinuum fiber lasers: new developments and applications

    NASA Astrophysics Data System (ADS)

    Devine, Adam; Hooper, Lucy; Clowes, John

    2016-05-01

    In this talk we give an overview of recent advances in the development of high power supercontinuum fiber lasers with powers exceeding 50W and spectral brightness of tens of mW/nm. We also discuss the fundamental limitations of power scaling and spectral broadening and review the existing and emerging applications of this unique light source which combines the broadband properties of a light bulb with the spatial properties of a laser.

  10. Advanced photoinjector laser and microwave technologies. Final report

    SciTech Connect

    Hartemann, F.V.; Luhmann, N.C. Jr.; Talley, W.K.

    1997-01-01

    An overview of the design parameters of the compact, high gradient, high luminosity X-band (8.568 GHz) photoinjector facility currently being developed as a collaborative effort between LLNL and UC Davis, is followed by a more detailed description of each of its major subsystems : X-band rf gun, GHz repetition rate synchronously modelocked AlGaAs quantum well laser oscillator, and 8-pass Ti: Al{sub 2}O{sub 3} chirped pulse laser amplifier. The photoinjector uses a high quantum efficiency ({approx}5%) Cs{sub 2}Te photocathode, and will be capable of producing high charge (> 1 nC), relativistic (5 MeV), ultrashort (< 1 ps) electron bunches at 2.142 GHz repetition rate in burst mode (100 photoelectron bunches). Design studies indicate that a normalized rms transverse emittance {epsilon}{sub n} = 0.75 {pi} mm-mrad is possible at 0.1 nC charge, while 2.5 {pi} mm-mrad can be obtained at 1 nC. A complete status report of our progress in the development and implementation of the design discussed herein is then given, together with initial experimental data concerning the performance of the 15 MW SLAC X-band klystron amplifier. Finally, the phase noise and jitter characteristics of the laser and rf systems of the high gradient X-band photoinjector have been measured experimentally. In this case, the laser oscillator is a self-modelocked Titanium:Sapphire system operating at the 108th subharmonic of the rf gun. The X-band signal is produced from the laser by a phase-locked dielectric resonance oscillator, and amplified by a pulsed TWT. A comparison between the TWT phase noise and the fields excited in the rf gun demonstrates the filtering effect of the high Q cavity resonant structure, thus indicating that the rf gun can be used as a master oscillator, and could be energized by either a magnetron or a cross-field amplifier.

  11. Solar Pumped Lasers and Their Applications

    NASA Technical Reports Server (NTRS)

    Lee, Ja H.

    1991-01-01

    Since 1980, NASA has been pursuing high power solar lasers as part of the space power beaming program. Materials in liquid, solid, and gas phases have been evaluated against the requirements for solar pumping. Two basic characteristics of solar insolation, namely its diffuse irradiance and 5800 K blackbody-like spectrum, impose rather stringent requirements for laser excitation. However, meeting these requirements is not insurmountable as solar thermal energy technology has progressed today, and taking advantage of solar pumping lasers is becoming increasingly attractive. The high density photons of concentrated solar energy have been used for mainly electric power generation and thermal processing of materials by the DOE Solar Thermal Technologies Program. However, the photons can interact with materials through many other direct kinetic paths, and applications of the concentrated photons could be extended to processes requiring photolysis, photosynthesis, and photoexcitation. The use of solar pumped lasers on Earth seems constrained by economics and sociopolitics. Therefore, prospective applications may be limited to those that require use of quantum effects and coherency of the laser in order to generate extremely high value products and services when conventional and inexpensive means are ineffective or impossible. The new applications already proposed for concentrated solar photons, such as destruction of hazardous waste, production of renewable fuel, production of fertilizer, and air/water pollution controls, may benefit from the use of inexpensive solar pumped laser matched with the photochemical kinetics of these processes.

  12. Solar pumped lasers and their applications

    NASA Astrophysics Data System (ADS)

    Lee, Ja H.

    Since 1980, NASA has been pursuing high power solar lasers as part of the space power beaming program. Materials in liquid, solid, and gas phases have been evaluated against the requirements for solar pumping. Two basic characteristics of solar insolation, namely its diffuse irradiance and 5800 K blackbody-like spectrum, impose rather stringent requirements for laser excitation. However, meeting these requirements is not insurmountable as solar thermal energy technology has progressed today, and taking advantage of solar pumping lasers is becoming increasingly attractive. The high density photons of concentrated solar energy have been used for mainly electric power generation and thermal processing of materials by the DOE Solar Thermal Technologies Program. However, the photons can interact with materials through many other direct kinetic paths, and applications of the concentrated photons could be extended to processes requiring photolysis, photosynthesis, and photoexcitation. The use of solar pumped lasers on Earth seems constrained by economics and sociopolitics. Therefore, prospective applications may be limited to those that require use of quantum effects and coherency of the laser in order to generate extremely high value products and services when conventional and inexpensive means are ineffective or impossible. The new applications already proposed for concentrated solar photons, such as destruction of hazardous waste, production of renewable fuel, production of fertilizer, and air/water pollution controls, may benefit from the use of inexpensive solar pumped laser matched with the photochemical kinetics of these processes.

  13. Biomedical applications of laser photoionization

    NASA Astrophysics Data System (ADS)

    Xiong, Xiaoxiong; Moore, Larry J.; Fassett, John R.; O'Haver, Thomas C.

    1991-07-01

    Trace elements are important for many essential metabolic functions. Zinc is a structural/functional component in more than 200 enzymes active in the biochemistry of cell division and tissue growth, neurology and endocrine control. Calcium is involved in intracellular control mechanisms and in skeletal bone building and resorption processes related to osteoporosis. Sensitive and selective laser photoionization is being developed to understand mechanisms in smaller samples and biological units approaching the cellular domain. Zinc has an ionization potential of 9.4 eV, or 75766.8 cm-1. Several processes are being explored, including two-photon resonant, three- photon ionization utilizing sequential UV transitions, e.g., 4s2 1S0 yields 4s4p 3P1 and 4s4p 3P1 yields 4s5d 3D1. Preliminary zinc stable isotope ratio data obtained by thermal atomization and laser photoionization agree with accepted values within 2 to 5%, except for anomalous 67Zn. Photoionization of calcium is being studied for isotope enrichment and ratio measurement using narrow and medium bandwidth lasers. Several ionization pathways, e.g., 4s2 1S0 - 2hv1 yields 4s10s - hv2 yields Ca+ (4s2S), are being investigated for isotopically selective ionization. Auto-ionization pathways are explored for greater efficiency in isotopic analysis. All studies have utilized a Nd:YAG- pumped laser system with one or two frequency-doubled tunable dye lasers coupled either to a magnetic sector or time-of-flight mass spectrometer.

  14. Laser displacement meter application for milling diagnostics

    NASA Astrophysics Data System (ADS)

    Ryabov, Oleg; Mori, Kazuo; Kasashima, Nagayoshi

    1998-09-01

    This paper presents the application of a laser displacement meter for direct multi-purpose sensing of milling tool conditions. Using a laser displacement meter, a laser beam is projected onto the cutting tool and subsequently reflected. The intensity as well as the angle of the reflected beam are measured. The signals are interpreted for identification of tool geometry, tool whirling, or vibration. Signal processing and analysis depend on the application. A prototype system has been developed to demonstrate the feasibility of various applications, namely (1) tool setting evaluation, (2) in-process measurement of milling cutter geometry and detection of tool failure, (3) continuous monitoring of milling cutter deterioration, (4) detection and measurement of chatter in milling, (5) measurement of milling tool bending and (6) thermal expansion.

  15. Novel atmospheric extinction measurement techniques for aerospace laser system applications

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark

    2013-01-01

    Novel techniques for laser beam atmospheric extinction measurements, suitable for manned and unmanned aerospace vehicle applications, are presented in this paper. Extinction measurements are essential to support the engineering development and the operational employment of a variety of aerospace electro-optical sensor systems, allowing calculation of the range performance attainable with such systems in current and likely future applications. Such applications include ranging, weaponry, Earth remote sensing and possible planetary exploration missions performed by satellites and unmanned flight vehicles. Unlike traditional LIDAR methods, the proposed techniques are based on measurements of the laser energy (intensity and spatial distribution) incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Various laser sources can be employed with wavelengths from the visible to the far infrared portions of the spectrum, allowing for data correlation and extended sensitivity. Errors affecting measurements performed using the proposed methods are discussed in the paper and algorithms are proposed that allow a direct determination of the atmospheric transmittance and spatial characteristics of the laser spot. These algorithms take into account a variety of linear and non-linear propagation effects. Finally, results are presented relative to some experimental activities performed to validate the proposed techniques. Particularly, data are presented relative to both ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm. This includes ground tests performed with 10 Hz and 20 kHz PRF NIR laser systems in a large variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft.

  16. Review of laser-driven ion sources and their applications.

    PubMed

    Daido, Hiroyuki; Nishiuchi, Mamiko; Pirozhkov, Alexander S

    2012-05-01

    scientific, industrial and medical applications of laser-driven proton or ion sources, some of which have already been established, while the others are yet to be demonstrated. In most applications, the laser-driven ion sources are complementary to the conventional accelerators, exhibiting significantly different properties. Finally, we summarize the paper.

  17. Optical resonator and laser applications

    NASA Technical Reports Server (NTRS)

    Taghavi-Larigani, Shervin (Inventor); Vanzyl, Jakob J. (Inventor); Yariv, Amnon (Inventor)

    2006-01-01

    The invention discloses a semi-ring Fabry-Perot (SRFP) optical resonator structure comprising a medium including an edge forming a reflective facet and a waveguide within the medium, the waveguide having opposing ends formed by the reflective facet. The performance of the SRFP resonator can be further enhanced by including a Mach-Zehnder interferometer in the waveguide on one side of the gain medium. The optical resonator can be employed in a variety of optical devices. Laser structures using at least one SRFP resonator are disclosed where the resonators are disposed on opposite sides of a gain medium. Other laser structures employing one or more resonators on one side of a gain region are also disclosed.

  18. Laser application in tracheobronchial tumors

    NASA Astrophysics Data System (ADS)

    Rau, B. Krishna; Krishna, Sharon

    2004-09-01

    Ninety three patients with obstructing tracheobronchial tumors were treated with Neodymium: Yttrium - Aluminum - Garnet (Nd:YAG) laser photocoagulation over a period of six years. There were sixty seven Males and 26 Females with a mean age of 44.3 years (range 6- 79 years). 21 benign and 72 malignant lesions were treated with a total 212 sessions of laser photocoagulation (mean 2.4 sessions). The anatomical distribution of lesions were as follows; larynx 9 (three benign and 6 malignant) trachea 39 (27 benign and 12 malignant) left main bronchus 27 (14 malignant) right main bronchus 24 (14 malignant) and vocal cords - 9 (three malignant). There were 21 patients with squamous cell carcinoma, two adenocarcinomas, one adenoid cystic carcinoma, 7 cases of locally infiltrating tumors from thyroid and esophagus, 6 cases of carcinoid tumor and 16 benign lesions. Twenty one patients had a tracheostomy tube in place when treatment was started. Eighteen of the 21 patients with tracheostomy were weaned off the tube in a mean of 5.5 days from the start of treatment. Lumen was restored in 31 (79.4%) patients. In the other eight (20.6%), lumen was achieved, but not sustained. Complications included bleeding in three cases which were managed conservatively, two cases of pneumothorax, and four cases of bronchospasm. There were six deaths during the follow up but none attributable to the procedure. Laser photocoagulation offered effective treatment in the majority of patients with obstructing tracheobronchial tumors, with acceptable morbidity.

  19. Scanning laser ophthalmoscopy. Clinical applications.

    PubMed

    Mainster, M A; Timberlake, G T; Webb, R H; Hughes, G W

    1982-07-01

    The scanning laser ophthalmoscope (SLO) provides a high-quality television image of the retina using less than 1/1000 of the light required for conventional indirect ophthalmoscopy. The SLO employs a new ophthalmoscopic principle in which a dim laser beam scans across the fundus, and light is collected only from one retinal point at a time. Since the instrument is highly light efficient, illumination levels are comfortable for the patient, and fluorescein angiography can be performed with one tenth of the usual fluorescein dose. Since a continuous, large depth of field view is displayed on the SLO screen and stored on video tape, repeated dynamic inspection of the vitreous, retina and vitreoretinal interface is afforded. In addition, any graphical material that can be displayed on a microcomputer monitor (such as text of video games) can also be impressed on the retinal pattern formed by the sweeping laser beam. The graphical material is thus observed directly by the patient and on the patient's retina by the clinician. Since the exact retinal locus of each point in the graphical material is viewed directly, it is possible to perform perimetry directly on the retina, to measure acuity at arbitrary retinal loci, to study how patients with macular disease use residual functional retina for reading, and to perform distortometry with a retinal (Amsler-type) grid.

  20. Electro-Optical Laser Technology. Curriculum Utilization. Final Report.

    ERIC Educational Resources Information Center

    Nawn, John H.

    This report describes a program to prepare students for employment as laser technicians and laser operators and to ensure that they have the necessary skills required by the industry. The objectives are to prepare a curriculum and syllabus for an associate degree program in Electro-Optical Laser Technology. The 2-year Electro-Optical Laser program…

  1. Eco-efficiency of laser welding applications

    NASA Astrophysics Data System (ADS)

    Kaierle, Stefan; Dahmen, Martin; Güdükkurt, Okan

    2011-05-01

    As widely known laser materials processing has some advantages regarding local heat input and controllability. In many fields applications were developed which are not accessible for conventional thermal processing. In other fields laser-supported manufacturing techniques are a valuable alternative. On the one hand laser techniques enable increased processing speed and less post-processing, leading to an increased productivity. On the other hand low efficiencies in the energy conversion seem to be a major drawback and apparently limit the range of applications. In the frame of conventional processing schemes laser beam welding requires a high utilization in order to run economically. Main advantages lie in the reduced consumption of material and the reduced efforts in post processing. Because of the locally concentrated heat input process emissions are lower which reduces energy and material consumption in the auxiliary chain. To make full use of the often-conjured flexibility a multitude of manufacturing schemes had been developed and adapted. In order to appraise the versatility of laser driven processing techniques a cost and benefit analysis based on a life-cycle approach is conducted including both, economics and ecology. Eco-efficiency is rated by a variation of the BASF method. Taking into account the reduced consumption of consumables, reduced effort for preparation and post-processing, and focusing on specific application ranges a positive environmental impact can be proven.

  2. Applications for Energy Recovering Free Electron Lasers

    SciTech Connect

    George Neil

    2007-08-01

    The availability of high-power, high-brilliance sources of tunable photons from energy-recovered Free Electron Lasers is opening up whole new fields of application of accelerators in industry. This talk will review some of the ideas that are already being put into production, and some of the newer ideas that are still under development.

  3. New Medical Applications Of Metal Vapor Lasers

    NASA Astrophysics Data System (ADS)

    Anderson, Robert S.; McIntosh, Alexander I.

    1989-06-01

    The first medical application for metal vapor lasers has been granted marketing approval by the FDA. This represents a major milestone for this technology. Metalaser Technologies recently received this approval for its Vasculase unit in the treatment of vascular lesions such as port wine stains, facial telangiectasia and strawberry hemangiomas.

  4. Advances in laser diodes for pyrotechnic applications

    NASA Technical Reports Server (NTRS)

    Craig, Richard R.

    1993-01-01

    Background information concerning the use of laser diodes in pyrotechnic applications is provided in viewgraph form. The following topics are discussed: damage limits, temperature stability, fiber coupling issues, and small (100 micron) and large (400 micron) fiber results. The discussions concerning fiber results concentrate on the areas of package geometry and electro-optical properties.

  5. LDRD Final Report: Adaptive Methods for Laser Plasma Simulation

    SciTech Connect

    Dorr, M R; Garaizar, F X; Hittinger, J A

    2003-01-29

    effective means of achieving adequate resolution in the crossing region while avoiding the expense of using the same fine grid everywhere, including the region between the beams where no LPI occurs. We applied ALPS to a suite of problems modeling crossed beam experiments performed on the Omega laser at the University of Rochester. Our simulations contributed to the theoretical interpretation of these experiments, which was recently published in Physical Review Letters [4]. This project has advanced the Laboratory's computational capabilities in the area of AMR algorithms and their application to LPI problems. The knowledge gained and software developed will contribute to the computational tools available for use in the design and interpretation of experiments to be performed at the National Ignition Facility (NIF) in support of Laboratory missions in stockpile stewardship, energy research and high energy density science.

  6. Laser weld jig. [Patent application

    DOEpatents

    Van Blarigan, P.; Haupt, D.L.

    1980-12-05

    A system is provided for welding a workpiece along a predetermined weld line that may be of irregular shape, which includes the step of forming a lip on the workpiece to extend parallel to the weld line, and moving the workpiece by engaging the lip between a pair of rotatable members. Rotation of one of the members at a constant speed, causes the workpiece to move so that all points on the weld line sequentially pass a fixed point in space at a constant speed, so that a laser welding beam can be directed at that fixed point to form a weld along the weld line. The workpiece can include a reusable jig forming the lip, and with the jig constructed to detachably hold parts to be welded at a position wherein the weld line of the parts extends parallel to the lip on the jig.

  7. Urological applications of the holmium laser

    NASA Astrophysics Data System (ADS)

    Beaghler, Marc A.; Poon, Michael W.; Ruckle, Herbert C.; Stewart, Steven C.; Weil, Dane

    1998-07-01

    While the role of endoscopy was initially diagnostic, the advent of improved endoscopes and working instruments have increased its therapeutic applications. One of the most recent advances is the holmium laser. It has a broad range of urological applications due to its ability to fragment all urinary calculi and its soft tissue effects. This laser is based on laser energy delivered in a pulsatile fashion at 2100 nm. The purpose of this study is to report our experience with the holmium laser. A retrospective study of patients undergoing endourological procedures with the holmium laser was performed. One hundred and forty patients underwent 157 procedures. The holmium laser was used for the treatment of urinary calculi in 122 patients. Stone location included 61 renal, 64 ureteral, and 17 bladder stones. Renal stone burden was 17 mm (range 3-50), ureteral stone size averaged 10 mm (range 3 - 35), and mean bladder stone size was 31 mm (range 10 - 60). Other uses included treatment of transitional cell carcinoma of the renal pelvis, ureter, and bladder, incision of ureteral strictures, ureterocele, and prostate, and ablation of renal hemangiomas. Intraoperative and post operative complications were noted. Follow-up for calculi consisted of a plain film of the abdomen at one week and an ultrasound or intravenous pyelogram at six to eight weeks post procedure. No ureteral perforations or strictures occurred. The Holmium laser was capable of fragmenting all urinary calculi in this study. No complications were directly attributable to the Holmium laser. In our initial experience, the Holmium laser is safe and effective in the treatment of urinary pathology. It is the most effective lithotrite available and is able to incise and coagulate soft tissue as well. This combination allows the urologist to treat a variety of urinary pathology using a single modality. Its main limitation is the ability to access lower pole lesions in the upper urinary tract due to the fiber

  8. High power gas laser - Applications and future developments

    NASA Technical Reports Server (NTRS)

    Hertzberg, A.

    1977-01-01

    Fast flow can be used to create the population inversion required for lasing action, or can be used to improve laser operation, for example by the removal of waste heat. It is pointed out that at the present time all lasers which are capable of continuous high-average power employ flow as an indispensable aspect of operation. High power laser systems are discussed, taking into account the gasdynamic laser, the HF supersonic diffusion laser, and electric discharge lasers. Aerodynamics and high power lasers are considered, giving attention to flow effects in high-power gas lasers, aerodynamic windows and beam manipulation, and the Venus machine. Applications of high-power laser technology reported are related to laser material working, the employment of the laser in controlled fusion machines, laser isotope separation and photochemistry, and laser power transmission.

  9. High power CO lasers and their application potential

    NASA Astrophysics Data System (ADS)

    Maisenhaelder, F.

    1989-06-01

    Industrial applications of high-power CO lasers are examined. The characteristics specific to CO lasers are briefly reviewed, and applications where the CO laser seems to promise wavelength-related advantages over other lasers are examined. Experimentally demonstrated applications in the drilling and cutting of metals, isotope separation and photochemistry, and laser medicine are addressed, Developments in the high power range in Japan, Soviet Union, and Germany are described, and a comparison is made between high power CO and CO2 gas lasers for civil applications.

  10. Laser induced fluorescence technique for environmental applications

    NASA Astrophysics Data System (ADS)

    Utkin, Andrei B.; Felizardo, Rui; Gameiro, Carla; Matos, Ana R.; Cartaxana, Paulo

    2014-08-01

    We discuss the development of laser induced fluorescence sensors and their application in the evaluation of water pollution and physiological status of higher plants and algae. The sensors were built on the basis of reliable and robust solid-state Nd:YAG lasers. They demonstrated good efficiency in: i) detecting and characterizing oil spills and dissolved organic matter; ii) evaluating the impact of stress on higher plants (cork oak, maritime pine, and genetically modified Arabidopsis); iii) tracking biomass changes in intertidal microphytobenthos; and iv) mapping macroalgal communities in the Tagus Estuary.

  11. 15 CFR 301.7 - Final disposition of an application.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AND APPARATUS FOR EDUCATIONAL AND SCIENTIFIC INSTITUTIONS § 301.7 Final disposition of an application. (a) Disposition of an application shall be final when 20 days have elapsed after publication of...

  12. 15 CFR 301.7 - Final disposition of an application.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... (a) Disposition of an application shall be final when 20 days have elapsed after publication of the... of the application. (c) An instrument, the duty-free entry of which has been finally denied, may...

  13. Advances in solid state laser technology for space and medical applications

    NASA Technical Reports Server (NTRS)

    Byvik, C. E.; Buoncristiani, A. M.

    1988-01-01

    Recent developments in laser technology and their potential for medical applications are discussed. Gas discharge lasers, dye lasers, excimer lasers, Nd:YAG lasers, HF and DF lasers, and other commonly used lasers are briefly addressed. Emerging laser technology is examined, including diode-pumped lasers and other solid state lasers.

  14. Ultrafast laser pulses for medical applications

    NASA Astrophysics Data System (ADS)

    Lubatschowski, Holger; Heisterkamp, Alexander; Will, Fabian; Serbin, Jesper; Bauer, Thorsten; Fallnich, Carsten; Welling, Herbert; Mueller, Wiebke; Schwab, Burkard; Singh, Ajoy I.; Ertmer, Wolfgang

    2002-04-01

    Ultrafast lasers have become a promising tool for micromachining and extremely precise ablation of all kinds of materials. Due to the low energy threshold, thermal and mechanical side effects are limited to the bu micrometers range. The neglection of side effects enables the use of ultrashort laser pulses in a broad field of medical applications. Moreover, the interaction process based on nonlinear absorption offers the opportunity to process transparent tissue three dimensionally inside the bulk. We demonstrate the feasibility of surgical procedures in different fields of medical interest: in ophthalmology intrastromal cutting and preparing of cornael flaps for refractive surgery in living animals is presented. Besides, the very low mechanical side effects enables the use of fs- laser in otoralyngology to treat ocecular bones. Moreover, the precise cutting quality can be used in fields of cardiovascular surgery for the treatment of arteriosklerosis as well as in dentistry to remove caries from dental hard tissue.

  15. Lasers '86; Proceedings of the Ninth International Conference on Lasers and Applications, Orlando, FL, Nov. 3-7, 1986

    SciTech Connect

    Mcmillan, R.W.

    1987-01-01

    Laser physics, technology, and applications are examined in reviews and reports. Topics addressed include VUV and X-ray lasers, vibrational energy transfer and kinetics, medical applications, ultrashort lasers and spectroscopy, surface and material interactions, lasers in atmospheric physics, and fiber-optic systems. Consideration is given to alexandrite lasers, four-wave mixing and nonlinear optics, chemical lasers, semiconductor lasers, photothermal and photoacoustic spectroscopy, dye lasers, optical phase conjugation and SBS, excimer lasers, SDI laser applications, remote-sensing with lasers, FELs, and applications in chemistry. Diagrams, drawings, graphs, and photographs are provided.

  16. Laser applications to atmospheric sciences: A bibliography

    NASA Technical Reports Server (NTRS)

    Harris, F. S., Jr.

    1975-01-01

    A bibliography is given of 1460 references of the applications of lasers to atmospheric sciences. The subjects covered include: aerosols; clouds; the distribution and motion of atmospheric natural and man-made constituents; winds; temperature; turbulence; scintillation; elastic, Raman and resonance scattering; fluorescence; absorption and transmission; the application of the Doppler effect and visibility. Instrumentation, in particular lidar, is included, also data handling, and interpretation of the data for meteorological processes. Communications, geodesy and rangefinding are not included as distinct areas. The application to the atmosphere is covered, but not the ocean or its surface.

  17. Semiconductor Lasers and Their Application in Optical Fiber Communication.

    ERIC Educational Resources Information Center

    Agrawal, Govind P.

    1985-01-01

    Working principles and operating characteristics of the extremely compact and highly efficient semiconductor lasers are explained. Topics include: the p-n junction; Fabry-Perot cavity; heterostructure semiconductor lasers; materials; emission characteristics; and single-frequency semiconductor lasers. Applications for semiconductor lasers include…

  18. Modeling Laser Effects on the Final Optics in Simulated IFE Environments

    SciTech Connect

    Nasr Ghoniem

    2004-08-14

    When laser light interacts with a material's surface, photons rapidly heat the electronic system, resulting in very fast energy transfer to the underlying atomic crystal structure. The intense rate of energy deposition in the shallow sub-surface layer creates atomic defects, which alter the optical characteristics of the surface itself. In addition, the small fraction of energy absorbed in the mirror leads to its global deformation by thermal and gravity loads (especially for large surface area mirrors). The aim of this research was to model the deformation of mirror surfaces at multiple length and time scales for applications in advanced Inertial Fusion Energy (IFE) systems. The goal is to control micro- and macro-deformations by material system and structural design. A parallel experimental program at UCSD has been set up to validate the modeling efforts. The main objective of the research program was to develop computer models and simulations for Laser-Induced Damage (LID) in reflective and transmissive final optical elements in IFE laser-based systems. A range of materials and material concepts were investigated and verified by experiments at UCSD. Four different classes of materials were considered: (1) High-reflectivity FCC metals (e.g. Cu, Au, Ag, and Al), (2) BCC metals (e.g. Mo, Ta and W), (3) Advanced material concepts (e.g. functionally graded material systems, amorphous coatings, and layered structures), and (4) Transmissive dielectrics (e.g. fused SiO2). In this report, we give a summary of the three-year project, followed by details in three areas: (1) Characterization of laser-induced damage; (2) Theory development for LIDT; and (3) Design of IFE reflective laser mirrors.

  19. Laser scanners: from industrial to biomedical applications

    NASA Astrophysics Data System (ADS)

    Duma, Virgil-Florin

    2013-11-01

    We present a brief overview of our contributions in the field of laser scanning technologies, applied for a variety of applications, from industrial, dimensional measurements to high-end biomedical imaging, such as Optical Coherence Tomography (OCT). Polygon Mirror (PM) scanners are presented, as applied from optical micrometers to laser sources scanned in frequency for Swept Sources (SSs) OCT. Galvanometer-based scanners (GSs) are approached to determine the optimal scanning function in order to obtain the highest possible duty cycle. We demonstrated that this optimal scanning function is linear plus parabolic, and not linear plus sinusoidal, as it has been previously considered in the literature. Risley prisms (rotational double wedges) scanners are pointed out, with our exact approach to determine and simulate their scan patterns in order to optimize their use in several types of applications, including OCT. A discussion on the perspectives of scanning in biomedical imaging, with a focus on OCT concludes the study.

  20. LaserHybrid welding for industrial applications

    NASA Astrophysics Data System (ADS)

    Staufer, H.

    2007-05-01

    In view of the demands made by the end users in the field of application of vehicle construction for an ever-higher product quality and improved performance, continuous innovations are considered to be absolutely decisive for being successful. This especially applies to the welding technology, and therefore the goal is to develop new, better and more powerful welding processes. In joining technology the high welding speed on the one and the good gap bridging ability on the other hand play a significant part. However, both features cannot be achieved by conventional laser welding processes. Therefore, a hybrid process is being. It is no doubt that the laser beam welding and the MIG welding have been established in the welding technology for very long, and that both processes allow a wide field of application in the joining technology. New possibilities and synergetic effects, however, are based on the combination of both processes.

  1. Femtosecond laser application in biotechnology and medicine

    NASA Astrophysics Data System (ADS)

    Koenig, Karsten

    2004-10-01

    Near-infrared (NIR) 80 MHz nanojoule femtosecond laser pulses of low sub-nanojoule and nJ pulse energies in combination with focusing optics of high numerical aperture can be used as versatile multiphoton tools in nanobiotechnology and nano/micro-medicine. Novel diagnostic applications include gene imaging by multiphoton multicolor FISH (MM-FISH) and high-resolution multiphoton tomography of skin as well as tissue engineered cardiovascular structures based on two-photon autofluorescence excitation and second harmonic generation (SHG) of endogenous biomolecules. Using high-intense (1011 - 1012 W/cm2) 80 MHz femtosecond laser beams, non-invasive targeted transfection of mammalian cells with DNA can be realized by creation of highly localized membrane perforations. Nanosurgery can be performed by optical knocking out of intracellular and intratissue structures. Potential applications include gene and cancer therapy, eye and brain surgery as well as optical engineering of single DNA molecules as key elements in bionanotechnology.

  2. Laser beamed power: Satellite demonstration applications

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Westerlund, Larry H.

    1992-01-01

    It is possible to use a ground-based laser to beam light to the solar arrays of orbiting satellites, to a level sufficient to provide all or some of the operating power required. Near-term applications of this technology for providing supplemental power to existing satellites are discussed. Two missions with significant commercial pay-off are supplementing solar power for radiation-degraded arrays and providing satellite power during eclipse for satellites with failed batteries.

  3. Resonant laser ablation: mechanisms and applications

    SciTech Connect

    Anderson, J.E.; Allen, T.M.; Garrett, A.W.; Gill, C.G.; Hemberger, P.H.; Kelly, P.B.; Nogar, N.S.

    1996-10-01

    We report on aspects of resonant laser ablation (RLA) behavior for a number of sample types: metals, alloys, thin films, zeolites and soil. The versatility of RLA is demonstrated, with results on a variety of samples and in several mass spectrometers. In addition, the application to depth profiling of thin films is described; absolute removal rates and detection limits are also displayed. A discussion of possible mechanisms for low-power ablation is presented.

  4. Applications for reactor-pumped lasers

    NASA Astrophysics Data System (ADS)

    Lipinski, R. J.; McArthur, D. A.

    Nuclear reactor-pumped lasers (RPL's) have been developed in the US by the Department of Energy for over two decades, with the primary research occurring at Sandia National Laboratories and Idaho National Engineering Laboratory. The US program has experimentally demonstrated reactor-pumped lasing in various mixtures of xenon, argon, neon, and helium at wavelengths of 585, 703, 725, 1,271, 1,733, 1,792, 2,032, 2,630, 2,650, and 3,370 nm with intrinsic efficiency as high as 2.5%. The major strengths of a reactor-pumped laser are continuous high-power operation, modular construction, self-contained power, compact size, and a variety of wavelengths (from visible to infrared). These characteristics suggest numerous applications not easily accessible to other laser types. The continuous high power of an RPL opens many potential manufacturing applications such as deep-penetration welding and cutting of thick structures, wide-area hardening of metal surfaces by heat treatment or cladding application, wide-area vapor deposition of ceramics onto metal surfaces, production of sub-micron sized particles for manufacturing of ceramics, and 3-D ceramic lithography. In addition, a ground-based RPL could beam its power to space for such activities as illuminating geosynchronous communication satellites in the earth's shadow to extend their lives, beaming power to orbital transfer vehicles, removing space debris, and providing power (from earth) to a lunar base during the long lunar night.

  5. High-power copper vapour lasers and applications

    SciTech Connect

    Chang, J.J.; Warner, B.E.; Boley, C.D.; Dragon, E.P.

    1995-08-01

    Expanded applications of copper vapor lasers has prompted increased demand for higher power and better beam quality. This paper reports recent progress in laser power scaling, MOPA operation, beam quality improvement, and applications in precision laser machining. Issues such as gas heating, radial delay, discharge instability, and window heating will also be discussed.

  6. Current applications of lasers in heart disease

    NASA Astrophysics Data System (ADS)

    Lee, Garrett; Chan, Ming C.; Mason, Dean T.

    1993-03-01

    Although the laser has been in existence for abut 30 years, its application in heart disease has only been examined in the past decade. Much attention has been given its exciting potential in treating coronary artery disease. Transmitted through a catheter comprised of one or more thin optical fibers which can be threaded nonsurgically into the coronary artery, the laser can ablate atherosclerotic plaque that obstructs the artery and diminishes blood flow to the myocardium. In clinical studies, the laser can treat some obstructive lesions that are not suitable for balloon angioplasty (i.e., long and diffuse lesions, very tight stenoses, ostial lesions, calcified lesions). In patients who failed balloon angioplasty due to severe dissection or abrupt closure, the laser may seal up the dissections and restore antegrade blood flow. In addition, the laser may have other applications and treatment modalities that are still under investigation. It may ablate ectopic ventricular foci, or terminate supraventricular tachyrhythmia by destroying the heart's abnormal conduction pathways. It can cut the hypertrophied septum that is associated with left ventricular outflow tract obstruction, or create a channel in the atrial septum as a palliative procedure in newborns with transposition of the great vessels. It may provide a wider orifice for blood flow within the heart in infants with pulmonary outflow obstruction and in adults with aortic valvular stenosis. It is also capable of fusing small thin-walled blood vessels together. Further, a more intriguing possibility is its use to bore several tiny channels in the myocardium to allow oxygenated blood from within the ventricular chamber to perfuse the ischemic heart tissue.

  7. Application of Low level Lasers in Dentistry (Endodontic)

    PubMed Central

    Asnaashari, Mohammad; Safavi, Nassimeh

    2013-01-01

    Low level lasers, cold or soft lasers: These lasers do not produce thermal effects on tissues and induce photoreactions in cells through light stimulation which is called photobiostimulation. Power of these lasers is usually under 250mW. The main point differentiating low level lasers and high power ones is the activation of photochemical reactions without heat formation. The most important factor to achieve this light characteristic in lasers is not their power, but their power density for each surfa ceunit (i.e cm2). Density lower than 670mW/cm2, can induce the stimulatory effects of low level lasers without thermal effects. Low level lasers (therapeutic) used today as treatment adjunctive devices in medicine and dentistry. Numerous studies have been performed on the applications of low level lasers in patient pain reduction. Mechanisms of pain reduction with therapeutic lasers and their application are expressed, and the studies realized in this field are presented. PMID:25606308

  8. Laser Disc Technology: A Visual Approach to Reading. Final Report.

    ERIC Educational Resources Information Center

    TIU Adult Education and Job Training Center, Lewistown, PA.

    A project developed a planned course of study using laser disc software to enhance social studies, science, and literature and the arts in Adult Basic Education (ABE)/General Educational Development (GED) reading classes. During the first part of the project, laser disc software was reviewed to ascertain what material was compatible with the…

  9. Laser applications in science education (LASE) games

    NASA Astrophysics Data System (ADS)

    Zafran, Robert

    1995-10-01

    Students love games using games? While racing the clock and other team, two to five member student teams are learning about laser applications, fiber optic principles, basic optics principles, interference filters, and other electro-optics phenomena. Three laser light, 'game oriented' activities, Mirrors, The Right Image, and Light Links, have proven to be a subtle and common-sense way to teaching students electro-optics technology principles by the direct experience of controlling a laser light beam, connecting fiber optics bundles, and manipulating combinations of convex and concave lenses. In the LASE Game Mirrors, student teams learn about reflection and the angles and locations involved in precisely directing a laser light to a targeted area. In Light Links, students experience the difficulty and the necessity of an 'absolute' match in the precise coupling necessary in the connection of multiple fiber optics bundles. Using the lens set from the Optical Society or America's Optics Discovery Kit, students are individually challenged to use various combinations of lenses to 'produce' The Right Image. Using these student centered activities, LASE Games has proven itself as an effective vehicle to teach students optically associated phenomena and simultaneously assist them to learn that team work is an essential ingredient in the completion of almost any multifaceted task.

  10. Technology and applications of ultrafast fiber lasers

    NASA Astrophysics Data System (ADS)

    Lang, Marion; Hellerer, Thomas; Stuhler, Juergen

    2011-11-01

    We briefly review the key technology of modern fiber based femtosecond laser sources summarizing advantages and disadvantages of different mode-locking solutions. A description of possible extensions of a FemtoFiber-type modelocked Er-doped fiber laser oscillator (1560 nm) reveals the flexibility with respect to wavelength coverage (488 nm .. 2200 nm) and pulse duration (10 fs .. 10 ps). The resulting FemtoFiber family and its versions for instrument integration allow one to use these state-of-the-art light sources in many important applications, e.g. THz spectroscopy and microscopy. We show that, depending on the fiber laser model and the THz emitter, THz radiation can be produced with 4-10 THz bandwidth and detected with up to 60 dB signal-to-noise ratio (SNR). Electronically controlled optical scanning (ECOPS) - a unique method for fast, precise and comfortable sampling of the THz pulse or other pump-probe experiments - is described and recommended for efficient data acquisition. As examples for modern microscopy with ultrafast fiber lasers we present results of two-photon fluorescence, coherent microscopy techniques (SHG/THG/CARS) and fluorescence lifetime imaging (FLIM).

  11. Technology and applications of ultrafast fiber lasers

    NASA Astrophysics Data System (ADS)

    Lang, Marion; Hellerer, Thomas; Stuhler, Juergen

    2012-03-01

    We briefly review the key technology of modern fiber based femtosecond laser sources summarizing advantages and disadvantages of different mode-locking solutions. A description of possible extensions of a FemtoFiber-type modelocked Er-doped fiber laser oscillator (1560 nm) reveals the flexibility with respect to wavelength coverage (488 nm .. 2200 nm) and pulse duration (10 fs .. 10 ps). The resulting FemtoFiber family and its versions for instrument integration allow one to use these state-of-the-art light sources in many important applications, e.g. THz spectroscopy and microscopy. We show that, depending on the fiber laser model and the THz emitter, THz radiation can be produced with 4-10 THz bandwidth and detected with up to 60 dB signal-to-noise ratio (SNR). Electronically controlled optical scanning (ECOPS) - a unique method for fast, precise and comfortable sampling of the THz pulse or other pump-probe experiments - is described and recommended for efficient data acquisition. As examples for modern microscopy with ultrafast fiber lasers we present results of two-photon fluorescence, coherent microscopy techniques (SHG/THG/CARS) and fluorescence lifetime imaging (FLIM).

  12. ARPA solid state laser and nonlinear materials program. Final report

    SciTech Connect

    Moulton, P.F.

    1994-06-01

    The Research Division of Schwartz Electro-Optics, as part of the ARPA Solid State Laser and Nonlinear Materials Program, conducted a three-year study Erbium-Laser-Based Infrared Sources. The aim of the study was to improve the understanding of semiconductor-laser-pumped, infrared (IR) solid state lasers based on the trivalent rare-earth ion erbium (Er) doped into a variety of host crystals. The initial program plan emphasized operation of erbium-doped materials on the 2.8-3.0 micrometers laser transition. Pulsed, Q-switched sources using that transition, when employed as a pump source for parametric oscillators, can provide tunable mid-IR energy. The dynamics of erbium lasers are more complex than conventional neodymium (Nd)-doped lasers and they intended to use pump-probe techniques to measure the level and temporal behavior of gain in various materials. To do so they constructed a number of different cw Er-doped lasers as probe sources and employed the Cr:LiSAF(LiSrAlF6) laser as a pulsed pump source that would simulate pulsed diode arrays. The authors identified the 970-nm wavelength pump band of Er as the most efficient and were able to make use of recently developed cw and pulsed InGaAs strained-quantum-well diode lasers in the effort. At the conclusion of the program they demonstrated the first pulsed diode bar pumping of the most promising materials for pulsed operation, the oxide garnets YSGG and GGG and the fluoride BaY2F8.

  13. Ultrafast pulse lasers jump to macro applications

    NASA Astrophysics Data System (ADS)

    Griebel, Martin; Lutze, Walter; Scheller, Torsten

    2016-03-01

    Ultrafast Lasers have been proven for several micro applications, e.g. stent cutting, for many years. Within its development of applications Jenoptik has started to use ultrafast lasers in macro applications in the automotive industry. The JenLas D2.fs-lasers with power output control via AOM is an ideal tool for closed loop controlled material processing. Jenoptik enhanced his well established sensor controlled laser weakening process for airbag covers to a new level. The patented process enables new materials using this kind of technology. One of the most sensitive cover materials is genuine leather. As a natural product it is extremely inhomogeneous and sensitive for any type of thermal load. The combination of femtosecond pulse ablation and closed loop control by multiple sensor array opens the door to a new quality level of defined weakening. Due to the fact, that the beam is directed by scanning equipment the process can be split in multiple cycles additionally reducing the local energy input. The development used the 5W model as well as the latest 10W release of JenLas D2.fs and achieved amazing processing speeds which directly fulfilled the requirements of the automotive industry. Having in mind that the average cycle time of automotive processes is about 60s, trials had been done of processing weakening lines in genuine leather of 1.2mm thickness. Parameters had been about 15 cycles with 300mm/s respectively resulting in an average speed of 20mm/s and a cycle time even below 60s. First samples had already given into functional and aging tests and passed successfully.

  14. High Power Fiber Lasers and Applications to Manufacturing

    NASA Astrophysics Data System (ADS)

    Richardson, Martin; McComb, Timothy; Sudesh, Vikas

    2008-09-01

    We summarize recent developments in high power fiber laser technologies and discuss future trends, particularly in their current and future use in manufacturing technologies. We will also describe our current research programs in fiber laser development, ultra-fast and new lasers, and will mention the expectations in these areas for the new Townes Laser Institute. It will focus on new core laser technologies and their applications in medical technologies, advanced manufacturing technologies and defense applications. We will describe a program on large mode area fiber development that includes results with the new gain-guiding approach, as well as high power infra-red fiber lasers. We will review the opportunities for high power fiber lasers in various manufacturing technologies and illustrate this with applications we are pursuing in the areas of femtosecond laser applications, advanced lithographies, and mid-IR technologies.

  15. Spaceborne laser development for future remote sensing applications

    NASA Astrophysics Data System (ADS)

    Stephen, Mark A.; Yu, Anthony W.; Krainak, Michael A.; Abshire, James B.; Harding, David J.; Riris, Haris; Li, Steven X.; Chen, Jeffrey; Numata, Kenji; Wu, Stewart; Camp, Jordan

    2011-09-01

    At NASA's Goddard Space Flight Center, we are developing the next generation laser transmitters for future remote sensing applications including a micropulse altimeter for ice-sheet monitoring, laser spectroscopic measurements and high resolution mapping of the Earth's surface as well as potential missions to other planets for trace gas measurement and mapping. In this paper we will present an overview of the spaceborne laser programs and offer insights into future spaceborne lasers for remote sensing applications.

  16. Tunable infrared laser sources and applications

    NASA Astrophysics Data System (ADS)

    Libatique, Nathaniel Joseph C.

    Fiber lasers are emerging as attractive alternative technologies for wavelength-selectable WDM sources because of a number of reasons which include: (1) their direct compatibility with the fiber-optic transmission medium, (2) the excellent amplifying properties of rare-earth doped fibers and the rapidly continuing progress in novel fiber gain media (i.e. L-Band, S-band, and Raman fiber amplifiers), (3) the potential for order-of-magnitude power scalability via the use of double-clad geometries, (4) the maturity and robustness of the laser diode pumps used, and (5) the ready availability of fiber-based components and fiber-pigtailed devices (i.e. fused couplers, Bragg gratings, polarization controllers, etalons). The tunable laser applications of interest to this work have two distinct performance requirements, the need for either continuous tunability (the ability to tune the lasing emission through a continuous range of wavelengths) or discrete tunability (the ability to switch the lasing emission to an arbitrarily-fixed set of wavelengths). The latter class of "push-button" switchability to pre-set wavelength channels is especially critical for WDM optical communications. In this Thesis, I will discuss experimental achievements and key issues related to the design and demonstration of these two classes of tunable lasers, with a special emphasis on channel-selectable sources for optical communications. In particular I will discuss: (1) Novel FBG-based rapidly wavelength-selectable WDM sources, the scaling of such FBG-string-based tunable sources to intermediate channel counts, and the demonstration of single frequency tunable WDM sources based on line-narrowed tunable FBGs. (2) The first demonstration of a potentially all-fiber wavelength-selectable WDM laser source based on a fiber Sagnac loop filter. (3) Wavelength-selectable WDM laser sources based on the novel use of a current-tunable (semiconductor Fabry-Perot) grid filter. (4) The first demonstration of a

  17. Future scientific applications for high-energy lasers

    SciTech Connect

    Lee, R.W.

    1994-08-01

    This report discusses future applications for high-energy lasers in the areas of astrophysics and space physics; hydrodynamics; material properties; plasma physics; radiation sources; and radiative properties.

  18. Application of high power lasers to space power and propulsion

    NASA Technical Reports Server (NTRS)

    Nored, D. L.

    1976-01-01

    The transmission of laser power over long distances for applications such as direct conversion to propulsive thrust or electrical power is considered. Factors discussed include: problems inherent in transmitting, propagating, and receiving the laser beam over long ranges; high efficiency, closed-cycle, continuous wave operation; advancement of CO2 laser technology; and compatibility with photovoltaic power conversion devices.

  19. Application of Laser Ablation Processing in Electric Power System Industries

    NASA Astrophysics Data System (ADS)

    Konagai, Chikara; Sano, Yuji; Nittoh, Koichi; Kuwako, Akira

    The present status of laser ablation processing applied in electric power system industries is reviewed. High average power LD-pumped Nd:YAG lasers with Q-switch have been developed and currently introduced into various applications. Optical fiber based laser beam delivery systems for Q-switched pulse laser are also being developed these years. Based on such laser and beam delivery technology, laser ablation processes are gradually introduced in maintenance of nuclear power plant, thermal power plant and electrical power distribution system. Cost effectiveness, robustness and reliability of the process is highly required for wide utilization in these fields.

  20. Computer Mediated Laser Videodisc Art Retrieval System. Final Report.

    ERIC Educational Resources Information Center

    Kempers, Bert A.

    If laser videodiscs are to become an important facet of computer-mediated education, cost-effective and time-effective methods of production must be found. Media Design Associates systematically investigated six ways to inexpensively transfer artwork to videodiscs. With each methodology, 204 pieces of varied artwork from the Biological Sciences…

  1. Development of a Curriculum in Laser Technology. Final Report.

    ERIC Educational Resources Information Center

    Wasserman, William J.

    A Seattle Central Community College project visited existing programs, surveyed need, and developed a curriculum for a future program in Laser-Electro-Optics (LEO) Technology. To establish contacts and view successful programs, project staff made visits to LEO technology programs at San Jose City College and Texas State Technical Institute, Center…

  2. Microgravity Spray Cooling Research for High Powered Laser Applications

    NASA Technical Reports Server (NTRS)

    Zivich, Chad P.

    2004-01-01

    An extremely powerful laser is being developed at Goddard Space Flight Center for use on a satellite. This laser has several potential applications. One application is to use it for upper atmosphere weather research. In this case, the laser would reflect off aerosols in the upper atmosphere and bounce back to the satellite, where the aerosol velocities could be calculated and thus the upper atmosphere weather patterns could be monitored. A second application would be for the US. Air Force, which wants to use the laser strategically as a weapon for satellite defense. The Air Force fears that in the coming years as more and more nations gain limited space capabilities that American satellites may become targets, and the laser could protect the satellites. Regardless of the ultimate application, however, a critical step along the way to putting the laser in space is finding a way to efficiently cool it. While operating the laser becomes very hot and must be cooled to prevent overheating. On earth, this is accomplished by simply running cool tap water over the laser to keep it cool. But on a satellite, this is too inefficient. This would require too much water mass to be practical. Instead, we are investigating spray cooling as a means to cool the laser in microgravity. Spray cooling requires much less volume of fluid, and thus could be suitable for use on a satellite. We have inherited a 2.2 second Drop Tower rig to conduct our research with. In our experiments, water is pressurized with a compressed air tank and sprayed through a nozzle onto our test plate. We can vary the pressure applied to the water and the temperature of the plate before an experiment trial. The whole process takes place in simulated microgravity in the 2.2 second Drop Tower, and a high speed video camera records the spray as it hits the plate. We have made much progress in the past few weeks on these experiments. The rig originally did not have the capability to heat the test plate, but I did

  3. Laser Ignition Technology for Bi-Propellant Rocket Engine Applications

    NASA Technical Reports Server (NTRS)

    Thomas, Matt; Bossard, John; Early, Jim; Trinh, Huu; Dennis, Jay; Turner, James (Technical Monitor)

    2001-01-01

    This viewgraph presentation gives an overview of laser ignition technology for bipropellant rocket engines applications. The objectives of this project include: (1) the selection test chambers and flows; (2) definition of the laser ignition setup; (3) pulse format optimization; (4) fiber optic coupled laser ignition system analysis; and (5) chamber integration issues definition. The testing concludes that rocket combustion chamber laser ignition is imminent. Support technologies (multiplexing, window durability/cleaning, and fiber optic durability) are feasible.

  4. High-power laser applications in Nippon Steel Corporation

    NASA Astrophysics Data System (ADS)

    Minamida, Katsuhiro

    2000-02-01

    The laser, which was invented in 1960, has been developed using various substances of solids, liquids, gases and semiconductors as laser active media. Applications of laser utilizing the coherent properties of laser light and the high power density light abound in many industries and in heavy industries respectively. The full-scale use of lasers in the steel industry began nearly 23 years ago with their applications as controllable light sources. Its contribution to the increase in efficiency and quality of the steel making process has been important and brought us the saving of the energy, the resource and the labor. Laser applications in the steel making process generally require high input energy, so it is essential to consider the interaction between the laser beam and the irradiated material. In particular, the reflectivity of the laser beam on the surface of material and the quantity of the laser-induced plasma are critical parameters for high efficient processes with low energy losses. We have developed plenty of new laser systems for the steel making process with their considerations in mind. A review of the following high-power-laser applications is given in the present paper: (1) Use of plasma as a secondary heat source in CO2 laser welding for connecting steel sheets of various grades. (2) Laser-assisted electric resistance welding of pipes. (3) New type all-laser-welded honeycomb panels for high-speed transport. (4) Laser flying welder for continuous hot rolling mill using two 45 kW CO2 lasers.

  5. Potential applications of the erbium:YAG laser in endourology.

    PubMed

    Fried, N M

    2001-11-01

    The holmium:YAG laser has become the laser of choice in endourology because of its multiple applications in the fragmentation of kidney stones, incision of strictures, and coagulation of tumors. This paper describes the potential use of a new laser, the erbium:YAG laser, for applications in endourology. Recent studies suggest that the Er:YAG laser may be superior to the Ho:YAG laser for precise ablation of strictures with minimal peripheral thermal damage and for more efficient laser lithotripsy. The Er:YAG laser cuts urethral and ureteral tissues more precisely than does the Ho:YAG laser, leaving a residual peripheral thermal damage zone of 30 +/- 10 microm compared with 290 +/- 30 microm for the Ho:YAG laser. This result may be important in the treatment of strictures, where residual thermal damage may induce scarring and result in stricture recurrence. The Er:YAG laser may represent an alternative to the cold knife and Ho:YAG laser in applications where minimal mechanical and thermal insult to tissue is required.

  6. Development of an application set for intraoperative and percutaneous laser-induced interstitial thermotherapy (LITT)

    NASA Astrophysics Data System (ADS)

    Roggan, Andre; Albrecht, Dirk; Berlien, Hans-Peter; Beuthan, Juergen; Germer, Christoph-Thomas; Koch, H.; Wodrich, Werner R.; Mueller, Gerhard J.

    1994-12-01

    A variable application-set was developed to enable a safe and effective LITT treatment. The set consists of various laser applicators, a protecting catheter and an introducing equipment. The laser applicator was developed with different radiation patterns to match the topological conditions of the diseased area. For MRI-controlled LITT treatments a special marker is mounted at the distal end of the glass fiber which facilitates its localization. To increase the patient's safety a special protecting catheter was designed which is temperature stable up to 250 degree(s)C and transparent for NIR-radiation. The catheter can be placed into the diseased area using the introducing equipment which consists of modified parts of standard interventional radiology equipment. The laser applicator is finally guided through the protecting catheter so that there is no direct contact between applicator and tissue. The system can be used both for intraoperative and for percutaneous treatments.

  7. Laser wakefield accelerator based light sources: potential applications and requirements

    SciTech Connect

    Albert, F.; Thomas, A. G.; Mangles, S. P.D.; Banerjee, S.; Corde, S.; Flacco, A.; Litos, M.; Neely, D.; Viera, J.; Najmudin, Z.; Bingham, R.; Joshi, C.; Katsouleas, T.

    2015-01-15

    In this article we review the prospects of laser wakefield accelerators as next generation light sources for applications. This work arose as a result of discussions held at the 2013 Laser Plasma Accelerators Workshop. X-ray phase contrast imaging, X-ray absorption spectroscopy, and nuclear resonance fluorescence are highlighted as potential applications for laser-plasma based light sources. We discuss ongoing and future efforts to improve the properties of radiation from plasma betatron emission and Compton scattering using laser wakefield accelerators for these specific applications.

  8. Wide spectrum antireflective coating for laser fusion systems. Final report

    SciTech Connect

    Yoldas, B.E; Partlow, D.P.; Smith, H.D.; Mattox, D.M.

    1984-01-13

    A method of depositing a laser damage resistant, wide-spectrum antireflective coating on fused silica has been developed. This work was sponsored under a subcontract with the University of California, with technical direction from the Lawrence Livermore National Laboratory. The coating is applied from a specific silanol polymer solution and converted to a porous SiO/sub 2/ film. The pore size of the film is first reduced by a heat treatment to prevent uv scattering. Then gradation of the pore volume is achieved by a mild etching to a sufficient depth to prevent a smoother index transition from air to the substrate glass. The resulting antireflectivity covers the entire transmission range of silica and may be extended to a wavelength as short as 250 nm. Laser damage thresholds as high as 9 j/cm/sup 2/ have been demonstrated on processed samples.

  9. Monitoring interfacial dynamics by pulsed laser techniques. Final report

    SciTech Connect

    Richmond, G.

    1995-12-31

    The research is aimed at understanding the structural, electronic, and reactive properties of semiconductors in solutions. Focus is on Si and GaAs surfaces because they are used in photovoltaic devices, etc. The pulsed laser techniques used included surface second harmonic generation in Si and laser induced photoluminescence in GaAs. SHG can measure space charge effects in the semiconductor under various conditions, ie, immersed in electrolyte, in presence of oxide overlayers, and under UHV conditions. The Si studies demonstrated the sensitivity of the phase of the SH response to space charge effects. With GaAs, time-correlated single photon counting methods were used in the picosecond time regime to examine the recombination luminescence following above band gap excitation (surface trapping velocities).

  10. Particle sizing experiments with the laser Doppler velocimeter: Final report

    SciTech Connect

    Giel, T.V. Jr.; Son, J.Y.

    1988-06-01

    Measurement techniques for in-situ simultaneous measurements of particle size distributions and particle velocities using the dual beam laser Doppler velocimeter (LV) were analytically and experimentally investigated. This investigation examined the different signal characteristics of the LV for determination of particle size and particle velocity, simultaneously. The different size related signal components were evaluated not only singularly but also as simultaneous measurements to determine which characteristic, or combination of characteristics, provided the best measure of particle size. The evaluation concentrated on the 0.5 to 5 ..mu..m particle size range, in which the LV light scattering characteristics are complex often non-monotonic functions of the particle size as well as functions of index of refraction, the laser light wavelength, laser intensity and polarization, and the location and response characteristics of the detector. Different components of the LV signal were considered, but analysis concentrated on Doppler phase, visibility and scatter-intensity because they show the greatest promise. These signals characteristics were initially defined analytically for numerous optical configurations over the 0.5 to 5 ..mu..m diameter range with 0.1 ..mu..m segmentation, for refractive index values from 1.0 to 3.0 with absorptive (imaginary) components varied form 0 to 1.0. Collector orientation and effective f/No., as well as fringe spacing, beam polarization and wavelength, were varied in this analytical evaluation. 18 refs., 42 figs., 5 tabs.

  11. Electron acceleration by laser fields in a gas. Final report

    SciTech Connect

    Fontana, J.R.

    1997-08-01

    The purpose of the project is an investigation of topics related to the high-energy acceleration of electrons by means of suitably shaped laser beams in an inert gaseous medium. By slowing down the phase velocity of the fields by its index of refraction, the gas allows a cumulative interaction with the electrons resulting in net acceleration and also focusing. The objectives of the work reported here were twofold: (1) to participate as a consultant in the design and analysis of demonstration experiments performed at the Brookhaven National Laboratory by STI Optronics, a Belleview, WA company, under a separate DOE funded contract; (2) to perform further analytic and design work on the laser acceleration scheme originally proposed and explore a possible extension of the method to acceleration in vacuum using the same field configuration and analogous interaction process as with a gas. This report thus comprises an account of both activities. Section 2 is an overview of the various laser acceleration methods that have been proposed, in order to provide a framework to the work reported. Section 3 contains a list of meetings attended by the Principal Investigator to present his work and interact with research community colleagues and STI staff, and a list of publications containing work he co-authored or was acknowledged for. Section 4 summarizes the work performed by STI to which he contributed. Section 5 consists of the technical reports the Principal Investigator wrote describing his independent theoretical work elaborating and extending the scope of the original project.

  12. Workshop on scientific and industrial applications of free electron lasers

    SciTech Connect

    Difilippo, F.C. ); Perez, R.B. Tennessee Univ., Knoxville, TN )

    1990-05-01

    A Workshop on Scientific and Industrial Applications of Free Electron Lasers was organized to address potential uses of a Free Electron Laser in the infrared wavelength region. A total of 13 speakers from national laboratories, universities, and the industry gave seminars to an average audience of 30 persons during June 12 and 13, 1989. The areas covered were: Free Electron Laser Technology, Chemistry and Surface Science, Atomic and Molecular Physics, Condensed Matter, and Biomedical Applications, Optical Damage, and Optoelectronics.

  13. Tenth Biennial Coherent Laser Radar Technology and Applications Conference

    NASA Technical Reports Server (NTRS)

    Kavaya, Michael J. (Compiler)

    1999-01-01

    The tenth conference on coherent laser radar technology and applications is the latest in a series beginning in 1980 which provides a forum for exchange of information on recent events current status, and future directions of coherent laser radar (or lidar or lader) technology and applications. This conference emphasizes the latest advancement in the coherent laser radar field, including theory, modeling, components, systems, instrumentation, measurements, calibration, data processing techniques, operational uses, and comparisons with other remote sensing technologies.

  14. Latest developments of ultrafast fiber laser and its material applications

    NASA Astrophysics Data System (ADS)

    Cho, G. C.; Liu, B.; Shah, L.; Liu, Z.; Che, Y.; Xu, J.

    2009-02-01

    We address recent fiber-based femtosecond laser technology. Specifically, fiber-chirped pulse amplifier is discussed for the enabling the concept of real-world applications. We review recent selected material applications demonstrating advantages of ultrafast dynamics of highly repetitive pulse train in nanoparticle generation in pulsed-laser deposition and reliable Si wafer singulation.

  15. Application of repumping laser in optical switching

    NASA Astrophysics Data System (ADS)

    Ray, Ayan; Ali, Md. Sabir; Chakrabarti, Alok

    2014-08-01

    The application of electromagnetically induced transparency (EIT) in high speed optical switching has remained as a key topic in research related to all optical switching. Demonstration of optical switching through EIT realized under ladder (Ξ) level coupling has been reported earlier. Due to narrow linewidth (ГEIT) and low coherent dephasing rate (γ) the EIT needs to be prepared only once to demonstrate such switching action. However, in a Ξ system the EIT is accompanied with double resonance optical pumping (DROP) signal, which is limited by spontaneous decay (Г) rates. It has been shown by our group that the simultaneous presence of DROP-EIT combination paves the way for executing a kind of slow-fast switching action. However the focus always remain on improving the modulation depth in such type of coherence assisted switch. Here we report a possible way to improve modulation depth by using an additional (named 'repumping' after convention used in laser cooling experiments) laser in the Ξ system. The 5S1/2→5P3/2→5D5/2 level coupling scheme of 87Rb atom is used in the current experiment.

  16. Reliability of Semiconductor Laser Packaging in Space Applications

    NASA Technical Reports Server (NTRS)

    Gontijo, Ivair; Qiu, Yueming; Shapiro, Andrew A.

    2008-01-01

    A typical set up used to perform lifetime tests of packaged, fiber pigtailed semiconductor lasers is described, as well as tests performed on a set of four pump lasers. It was found that two lasers failed after 3200, and 6100 hours under device specified bias conditions at elevated temperatures. Failure analysis of the lasers indicates imperfections and carbon contamination of the laser metallization, possibly from improperly cleaned photo resist. SEM imaging of the front facet of one of the lasers, although of poor quality due to the optical fiber charging effects, shows evidence of catastrophic damage at the facet. More stringent manufacturing controls with 100% visual inspection of laser chips are needed to prevent imperfect lasers from proceeding to packaging and ending up in space applications, where failure can result in the loss of a space flight mission.

  17. Laser recrystallization of compound semiconductor films. Final report

    SciTech Connect

    Chu, T.L.; Chu, S.C.; Jiang, C.L.; Lin, S.C.; Stokes, E.D.; Yu, J.M.

    1985-01-01

    Considerable efforts have recently been directed to the research and development of thin polycrystallins film photovoltaic devices from direct gap semiconductors with the objective of producing low cost photovoltaic systems. The conversion efficiencies of thin film devices, in most cases, are considerably lower than those of corresponding single crystalline devices due to the grain boundary effects. Extensive investigations thus far have not developed effective techniques to eliminate the grain boundary effects. The objective of this program is to determine the feasibility of using laser recrystallization for the passivation and reduction of grain boundaries in thin semiconductor films. The recrystallization of thin films of cadmium telluride, gallium arsenide, indium phosphide, and zinc phosphide using a pulsed (5 kHz) Nd:YAG laser has been investigated by scanning a laser beam over the specimen surface with successive overlapping scan lines. At a fixed scan rate, the optimum energy density for the recrystallization of the compound semiconductor films was determined. Electron microprobe analysis and electrical characteristics of Schottky barriers indicated the decomposition of these films during recrystallization. The relative extent of decomposition is related to the dissociation pressure of the semiconductor at its melting point. For example, the dissociation pressure of gallium arsenide is considerably lower than that of indium phosphide. The chemical and structural damages in recrystallized gallium arsenide films can be removed by annealing in an arsine atmosphere while those in recrystallized indium phosphide films cannot. Although the recrystallized films are not directly useful for device purposes, homoepitaxial films of compound semiconductors, such as cadium telluride, deposited on recrystallized films have produced photovoltaic devices with improved characteristics.

  18. Biophysics applications of free-electron lasers

    NASA Astrophysics Data System (ADS)

    Austin, Robert H.

    1993-07-01

    There has been a significant financial effort poured into the technology of the Free Electron Laser (FEL) over the last 15 years or so. Much of that money was spent in the hopes that the FEL would be a key element in the Strategic Defense Initiative, but a small fraction of money was allocated for the Medical FEL program. The Medical FELs program was aimed at exploring how the unique capabilities of the FEL could be utilized in medical applications. Part of the Medical FEl effort has been in clinical applications, but some of the effort has also been put into exploring applications of the FEL for fundamental biological physics. It is the purpose of this brief text to outline some of the fundamental biophysics I have done, and some plans we have for the future. Since the FEL is (still) considered to be an avant garde device, the reader should not be surprised to find that much of the work proposed here is also rather radical and avant garde.

  19. Medical Applications of Laser Induced Breakdown Spectroscopy

    NASA Astrophysics Data System (ADS)

    Pathak, A. K.; Rai, N. K.; Singh, Ankita; Rai, A. K.; Rai, Pradeep K.; Rai, Pramod K.

    2014-11-01

    Sedentary lifestyle of human beings has resulted in various diseases and in turn we require a potential tool that can be used to address various issues related to human health. Laser Induced Breakdown Spectroscopy (LIBS) is one such potential optical analytical tool that has become quite popular because of its distinctive features that include applicability to any type/phase of samples with almost no sample preparation. Several reports are available that discusses the capabilities of LIBS, suitable for various applications in different branches of science which cannot be addressed by traditional analytical methods but only few reports are available for the medical applications of LIBS. In the present work, LIBS has been implemented to understand the role of various elements in the formation of gallstones (formed under the empyema and mucocele state of gallbladder) samples along with patient history that were collected from Purvancal region of Uttar Pradesh, India. The occurrence statistics of gallstones under the present study reveal higher occurrence of gallstones in female patients. The gallstone occurrence was found more prevalent for those male patients who were having the habit of either tobacco chewing, smoking or drinking alcohols. This work further reports in-situ LIBS study of deciduous tooth and in-vivo LIBS study of human nail.

  20. CHRONICLE: International forum on advanced high-power lasers and applications (AHPLA '99)

    NASA Astrophysics Data System (ADS)

    Afanas'ev, Yurii V.; Zavestovskaya, I. N.; Zvorykin, V. D.; Ionin, Andrei A.; Senatsky, Yu V.; Starodub, Aleksandr N.

    2000-05-01

    A review of reports made on the International Forum on Advanced High-Power Lasers and Applications, which was held at the beginning of November 1999 in Osaka (Japan), is presented. Five conferences were held during the forum on High-Power Laser Ablation, High-Power Lasers in Energy Engineering, High-Power Lasers in Civil Engineering and Architecture, High-Power Lasers in Manufacturing, and Advanced High-Power Lasers. The following trends in the field of high-power lasers and their applications were presented: laser fusion, laser applications in space, laser-triggered lightning, laser ablation of materials by short and ultrashort pulses, application of high-power lasers in manufacturing, application of high-power lasers in mining, laser decommissioning and decontamination of nuclear reactors, high-power solid-state and gas lasers, x-ray and free-electron lasers. One can find complete information on the forum in SPIE, vols. 3885-3889.

  1. Applications of absorption spectroscopy using quantum cascade lasers.

    PubMed

    Zhang, Lizhu; Tian, Guang; Li, Jingsong; Yu, Benli

    2014-01-01

    Infrared laser absorption spectroscopy (LAS) is a promising modern technique for sensing trace gases with high sensitivity, selectivity, and high time resolution. Mid-infrared quantum cascade lasers, operating in a pulsed or continuous wave mode, have potential as spectroscopic sources because of their narrow linewidths, single mode operation, tunability, high output power, reliability, low power consumption, and compactness. This paper reviews some important developments in modern laser absorption spectroscopy based on the use of quantum cascade laser (QCL) sources. Among the various laser spectroscopic methods, this review is focused on selected absorption spectroscopy applications of QCLs, with particular emphasis on molecular spectroscopy, industrial process control, combustion diagnostics, and medical breath analysis.

  2. Applications of Absorption Spectroscopy Using Quantum Cascade Lasers.

    PubMed

    2014-10-01

    Infrared laser absorption spectroscopy (LAS) is a promising modern technique for sensing trace gases with high sensitivity, selectivity, and high time resolution. Mid-infrared quantum cascade lasers, operating in a pulsed or continuous wave mode, have potential as spectroscopic sources because of their narrow linewidths, single mode operation, tunability, high output power, reliability, low power consumption, and compactness. This paper reviews some important developments in modern laser absorption spectroscopy based on the use of quantum cascade laser (QCL) sources. Among the various laser spectroscopic methods, this review is focused on selected absorption spectroscopy applications of QCLs, with particular emphasis on molecular spectroscopy, industrial process control, combustion diagnostics, and medical breath analysis.

  3. Applications of laser precisely processing technology in solar cells

    NASA Astrophysics Data System (ADS)

    Wang, Hong-Jie; Cheng, Hua; Xie, Kang-Wen; Lu, Fu-Yun; Du, Yong-Chao

    2007-09-01

    According to the design method of laser resonator cavity, we optimized the primary parameters of resonator and utilized LD arrays symmetrically pumping manner to implementing output of the high-brightness laser in our laser cutter, then which was applied to precisely cutting the conductive film of CuInSe2 solar cells, the buried contact silicon solar cells’ electrode groove, and perforating in wafer which is used to the emitter wrap through silicon solar cells. Laser processing precision was less than 40 μ m, the results have met solar cell’s fabrication technology, and made finally the buried cells’ conversion efficiency be improved from 18% to 21%.

  4. Regulatory applications of sediment criteria. Final report

    SciTech Connect

    Not Available

    1987-06-23

    The report briefly describes the development of sediment criteria, discusses their utility and appropriate regulatory applications, and recommends steps to enhance the acceptance of sediment criteria by the regulatory and regulated communities.

  5. Laser application in otology for hearing restoration

    NASA Astrophysics Data System (ADS)

    Lombardo, Igino

    1994-09-01

    Prior to the development of the stapes replacement prosthesis in the early 1950s, loss of hearing due to otosclerosis remained an untreatable disease. Today, loss of hearing due to otosclerosis can be restored in the majority of cases to near normal levels. Since 1980 the laser has played a major and important role in otosclerosis surgery. This paper explores the use of lasers for hearing restoration and compares the results of laser surgery to non-laser surgery.

  6. Laser Wakefield Acceleration Driven by a CO2 Laser (STELLA-LW) - Final Report

    SciTech Connect

    Kimura, Wayne D

    2008-06-27

    The original goals of the Staged Electron Laser Acceleration – Laser Wakefield (STELLA-LW) program were to investigate two new methods for laser wakefield acceleration (LWFA). In pseudo-resonant LWFA (PR-LWFA), a laser pulse experiences nonlinear pulse steepening while traveling through the plasma. This steepening allows the laser pulse to generate wakefields even though the laser pulse length is too long for resonant LWFA to occur. For the conditions of this program, PR-LWFA requires a minimum laser peak power of 3 TW and a low plasma density (10^16 cm^-3). Seeded self-modulated LWFA (seeded SM-LWFA) combines LWFA with plasma wakefield acceleration (PWFA). An ultrashort (~100 fs) electron beam bunch acts as a seed in a plasma to form a wakefield via PWFA. This wakefield is subsequently amplified by the laser pulse through a self-modulated LWFA process. At least 1 TW laser power and, for a ~100-fs bunch, a plasma density ~10^17 cm^-3 are required. STELLA-LW was located on Beamline #1 at the Brookhaven National Laboratory (BNL) Accelerator Test Facility (ATF). The ATF TW CO2 laser served as the driving laser beam for both methods. For PR-LWFA, a single bunch was to probe the wakefield produced by the laser beam. For seeded SM-LWFA, the ATF linac would produce two bunches, where the first would be the seed and the second would be the witness. A chicane would compress the first bunch to enable it to generate wakefields via PWFA. The plasma source was a short-length, gas-filled capillary discharge with the laser beam tightly focused in the center of the capillary, i.e., no laser guiding was used, in order to obtain the needed laser intensity. During the course of the program, several major changes had to be made. First, the ATF could not complete the upgrade of the CO2 laser to the 3 TW peak power needed for the PR-LWFA experiment. Therefore, the PR-LWFA experiment had to be abandoned leaving only the seeded SM-LWFA experiment. Second, the ATF discovered that the

  7. Ultra-intense Laser Applications to the Industries at GPI

    SciTech Connect

    Kitagawa, Yoneyoshi; Mori, Yoshitaka; Ootsuka, Shuji; Makino, Takahiro; Ohta, Mari; Suzuki, Tetsuya; Kuwabara, Hajime

    2009-01-22

    The laser accelerator provides us not only ultra high field, but also extremely short pulse radiation sources, the laser-produced X-rays. Using a 1.2 TW table-top Ti:sap laser, we are pursuing the activities for the industrial application. First we proposed a new injection acceleration scheme using the ultra short beat-wave accelerator for the economical radiation source. Then we proposed two applications both on the backward see-through vision of distant objects using the laser X-rays, and on the X-ray illumination on Aspergillus awamori spores, which is 100 times effective of the current X-ray tube cases.

  8. Development and clinical application of excimer laser corneal shaping

    NASA Astrophysics Data System (ADS)

    Homolka, Peter; Biowski, R.; Husinsky, Wolfgang; Blaas, C.; Simader, Ch.; Baumgartner, I. Gosch; Kaminski, Stefan; Grabner, G.

    1998-06-01

    Excimer Laser Corneal Shaping using an 193 nm Excimer Laser (ArF) provides a possibility for the fabrication of corneal transplants of various forms for various clinical applications such as (epi-)keratoplasty. Another area of application envisioned is the production of 'living contact lenses' for epikeratophakia. A device for lathing and perforating corneal donor tissue with a scanning laser beam is presented. A new ablation algorithm (Optimized Scanning Laser Ablation) was recently developed and increased the quality of lenticules and donor buttons considerably.

  9. High-power lasers for directed-energy applications.

    PubMed

    Sprangle, Phillip; Hafizi, Bahman; Ting, Antonio; Fischer, Richard

    2015-11-01

    In this article, we review and discuss the research programs at the Naval Research Laboratory (NRL) on high-power lasers for directed-energy (DE) applications in the atmosphere. Physical processes affecting propagation include absorption/scattering, turbulence, and thermal blooming. The power levels needed for DE applications require combining a number of lasers. In atmospheric turbulence, there is a maximum intensity that can be placed on a target that is independent of the initial beam spot size and laser beam quality. By combining a number of kW-class fiber lasers, scientists at the NRL have successfully demonstrated high-power laser propagation in a turbulent atmosphere and wireless recharging. In the NRL experiments, four incoherently combined fiber lasers having a total power of 5 kW were propagated to a target 3.2 km away. These successful high-power experiments in a realistic atmosphere formed the basis of the Navy's Laser Weapon System. We compare the propagation characteristics of coherently and incoherently combined beams without adaptive optics. There is little difference in the energy on target between coherently and incoherently combined laser beams for multi-km propagation ranges and moderate to high levels of turbulence. Unlike incoherent combining, coherent combining places severe constraints on the individual lasers. These include the requirement of narrow power spectral linewidths in order to have long coherence times as well as polarization alignment of all the lasers. These requirements are extremely difficult for high-power lasers. PMID:26560609

  10. High-power lasers for directed-energy applications.

    PubMed

    Sprangle, Phillip; Hafizi, Bahman; Ting, Antonio; Fischer, Richard

    2015-11-01

    In this article, we review and discuss the research programs at the Naval Research Laboratory (NRL) on high-power lasers for directed-energy (DE) applications in the atmosphere. Physical processes affecting propagation include absorption/scattering, turbulence, and thermal blooming. The power levels needed for DE applications require combining a number of lasers. In atmospheric turbulence, there is a maximum intensity that can be placed on a target that is independent of the initial beam spot size and laser beam quality. By combining a number of kW-class fiber lasers, scientists at the NRL have successfully demonstrated high-power laser propagation in a turbulent atmosphere and wireless recharging. In the NRL experiments, four incoherently combined fiber lasers having a total power of 5 kW were propagated to a target 3.2 km away. These successful high-power experiments in a realistic atmosphere formed the basis of the Navy's Laser Weapon System. We compare the propagation characteristics of coherently and incoherently combined beams without adaptive optics. There is little difference in the energy on target between coherently and incoherently combined laser beams for multi-km propagation ranges and moderate to high levels of turbulence. Unlike incoherent combining, coherent combining places severe constraints on the individual lasers. These include the requirement of narrow power spectral linewidths in order to have long coherence times as well as polarization alignment of all the lasers. These requirements are extremely difficult for high-power lasers.

  11. Laser scattering from long scalelength plasmas on Omega. Final report

    SciTech Connect

    Drake, R.P.; Seka, W.; Craxton, R.S.; Bauer, B.S.

    1998-12-31

    In this project, the authors accomplished the tasks called for in the revised statement of work associated with this grant. Specifically, they accomplished: (1) active participation in the design of long-scalelength plasmas for Omega and in experiments to characterize these plasmas; (2) development of software that permits the rapid evaluation of laser-scattering diagnostic possibilities involving the standard parametric instabilities. It must be able to account for all 60 beams in Omega in addition to a probe beam and variable detector locations; and (3) design, purchase of components for, and assembly of instrumentation to make such measurements, providing for long-term versatility in the type of measurement. The project background and these accomplishments are discussed.

  12. Laser fusion driven breeder design study. Final report

    SciTech Connect

    Berwald, D.H.; Massey, J.V.

    1980-12-01

    The results of the Laser Fusion Breeder Design Study are given. This information primarily relates to the conceptual design of an inertial confinement fusion (ICF) breeder reactor (or fusion-fission hybrid) based upon the HYLIFE liquid metal wall protection concept developed at Lawrence Livermore National Laboratory. The blanket design for this breeder is optimized to both reduce fissions and maximize the production of fissile fuel for subsequent use in conventional light water reactors (LWRs). When the suppressed fission blanket is compared with its fast fission counterparts, a minimal fission rate in the blanket results in a unique reactor safety advantage for this concept with respect to reduced radioactive inventory and reduced fission product decay afterheat in the event of a loss-of-coolant-accident.

  13. Future prospects in dermatologic applications of lasers, nanotechnology, and other new technologies.

    PubMed

    Boixeda, P; Feltes, F; Santiago, J L; Paoli, J

    2015-04-01

    We review novel technologies with diagnostic and therapeutic applications in dermatology. Among the diagnostic techniques that promise to become part of dermatologic practice in the future are optical coherence tomography, multiphoton laser scanning microscopy, Raman spectroscopy, thermography, and 7-T magnetic resonance imaging. Advances in therapy include novel light-based treatments, such as those applying lasers to new targets and in new wavelengths. Devices for home therapy are also appearing. We comment on the therapeutic uses of plasma, ultrasound, radiofrequency energy, total reflection amplification of spontaneous emission of radiation, light stimulation, and transepidermal drug delivery. Finally, we mention some basic developments in nanotechnology with prospects for future application in dermatology.

  14. CO2 laser devices and applications; Proceedings of the Seminar, Washington, DC, April 10, 11, 1980

    NASA Astrophysics Data System (ADS)

    Hartwick, T. S.

    1980-01-01

    Studies contained in this volume provide an overview of the recent advances in CO2 lasers and CO2 laser systems and their commercial and military applications. Papers are presented on the development of a flyable CO2 laser beacon, a frequency-stabilized hybrid CO2 lasers, compact CO2 lasers, and pulsed CO2 lasers. Other papers include: carbon dioxide lasers in rangefinding, scanning laser Doppler anemometry system, wide-bandwidth CO2 laser photomixers, infrared fiber optics for CO2 laser applications, and industrial applications of far-infrared lasers.

  15. Laser polishing of niobium for SRF applications

    SciTech Connect

    Zhao, Liang; Klopf, J. Michael; Reece, Charles E.; Kelley, Michael

    2013-09-01

    Smooth interior surfaces are desired for niobium SRF cavities, now obtained by buffered chemical polish (BCP) and/or electropolish (EP). Laser polishing is a potential alternative, having advantages of speed, freedom from chemistry and in-process inspection. Here we show that laser polishing can produce smooth topography with Power Spectral Density (PSD) measurements similar to that obtained by EP. We studied the influence of the laser power density and laser beam raster rate on the surface topography. These two factors need to be combined carefully to smooth the surface without damaging it. Computational modeling was used to simulate the surface temperature and explain the mechanism of laser polishing.

  16. Applications of Adaptive Optics Scanning Laser Ophthalmoscopy

    PubMed Central

    Roorda, Austin

    2010-01-01

    Adaptive optics (AO) describes a set of tools to correct or control aberrations in any optical system. In the eye, AO allows for precise control of the ocular aberrations. If used to correct aberrations over a large pupil, for example, cellular level resolution in retinal images can be achieved. AO systems have been demonstrated for advanced ophthalmoscopy as well as for testing and/or improving vision. In fact, AO can be integrated to any ophthalmic instrument where the optics of the eye is involved, with a scope of applications ranging from phoropters to optical coherence tomography systems. In this paper, I discuss the applications and advantages of using AO in a specific system, the adaptive optics scanning laser ophthalmoscope, or AOSLO. Since the Borish award was, in part, awarded to me because of this effort, I felt it appropriate to select this as the topic for this paper. Furthermore, users of AOSLO continue to appreciate the benefits of the technology, some of which were not anticipated at the time of development, and so it is time to revisit this topic and summarize them in a single paper. PMID:20160657

  17. Application of laser microbeam in biopharmacy

    NASA Astrophysics Data System (ADS)

    Zhao, Yansheng; Wang, Ming; Wang, Luyan; Li, Taiming; Wu, Junmin; Xu, Lei; Zhu, Xi

    1999-09-01

    Laser microbeam system consists of a third harmonic generation Nd:YAG laser and an inverted biological microscope. It is the first time that laser microbeam is applied in immobilized cell to produce midecamycin (MDM). After laser irradiation, the penetrance of immobilized granule greatly increased, probably through the microchannel made by laser. The results showed that the MDM productivity was increased greatly and the half-life of immobilized mycelia prolonged over three times as long as that of the control. In another experiment, plasmid pS65T (including green fluorescent protein genes) and plasmid pUH-10 (including Amp resistant gene) were successfully introduced into E. coli by laser microbeam. The results show that laser microbeam has a bright perspective on biopharmacy.

  18. Laser anemometry techniques for turbine applications

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.; Oberle, Lawrence G.

    1987-01-01

    Laser anemometry offers a nonintrusive means for obtaining flow field information. Current research at NASA Lewis Research Center is focused on instrumenting a warm turbine facility with a laser anemometer system. In an effort to determine the laser anemometer system best qualified for the warm turbine environment, the performance of a conventional laser fringe anemometer and a two spot time of flight system were compared with a new, modified time of flight system, called a Four Spot laser anemometer. The comparison measurements were made in highly turbulent flows near walls. The Four Spot anemometer uses elliptical spots to increase the flow acceptance angle to be comparable to that of a Laser Fringe Anemometer. Also, the Four Spot uses an optical code that vastly simplifies the pulse detection processor. The results of the comparison measurements will exemplify which laser anemometer system is best suited to the hostile environment typically encountered in warm rotating turbomachinery.

  19. Laser applications in machining slab materials

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoping

    1990-10-01

    Since the invention of the laser back in 1960, laser technology has been extensively applied in many fields of science and technology. These has been a history of nearly two decades of using lasers as an energy source in machining materials, such as cutting, welding, ruling and boring, among other operations. With the development of flexible automation in production, the advantages of laser machining have has grown more and more obvious. The combination of laser technology and computer science further promotes the enhancement and upgrading of laser machining and related equipment. At present, many countries are building high quality laser equipment for machining slab materials, such as the Coherent and Spectra Physics corporations in the United States, the Trumpf Corporation in West Germany, the Amada Corporation in Japan, and the Bystronic Corporation in Switzerland, among other companies.

  20. Application of laser Doppler velocimeter to chemical vapor laser system

    NASA Technical Reports Server (NTRS)

    Gartrell, Luther R.; Hunter, William W., Jr.; Lee, Ja H.; Fletcher, Mark T.; Tabibi, Bagher M.

    1993-01-01

    A laser Doppler velocimeter (LDV) system was used to measure iodide vapor flow fields inside two different-sized tubes. Typical velocity profiles across the laser tubes were obtained with an estimated +/-1 percent bias and +/-0.3 to 0.5 percent random uncertainty in the mean values and +/-2.5 percent random uncertainty in the turbulence-intensity values. Centerline velocities and turbulence intensities for various longitudinal locations ranged from 13 to 17.5 m/sec and 6 to 20 percent, respectively. In view of these findings, the effects of turbulence should be considered for flow field modeling. The LDV system provided calibration data for pressure and mass flow systems used routinely to monitor the research laser gas flow velocity.

  1. The NASA high power carbon dioxide laser: A versatile tool for laser applications

    NASA Technical Reports Server (NTRS)

    Lancashire, R. B.; Alger, D. L.; Manista, E. J.; Slaby, J. G.; Dunning, J. W.; Stubbs, R. M.

    1976-01-01

    A closed-cycle, continuous wave, carbon dioxide high power laser has been designed and fabricated to support research for the identification and evaluation of possible high power laser applications. The device is designed to generate up to 70 kW of laser power in annular shape beams from 1 to 9 cm in diameter. Electric discharge, either self sustained or electron beam sustained, is used for excitation. This laser facility provides a versatile tool on which research can be performed to advance the state-of-the-art technology of high power CO2 lasers in such areas as electric excitation, laser chemistry, and quality of output beams. The facility provides a well defined, continuous wave beam for various application experiments, such as propulsion, power conversion, and materials processing.

  2. Properties and Applications of Laser Generated X-Ray Sources

    SciTech Connect

    Smith, R F; Key, M H

    2002-02-25

    The rapid development of laser technology and related progress in research using lasers is shifting the boundaries where laser based sources are preferred over other light sources particularly in the XUV and x-ray spectral region. Laser based sources have exceptional capability for short pulse and high brightness and with improvements in high repetition rate pulsed operation, such sources are also becoming more interesting for their average power capability. This study presents an evaluation of the current capabilities and near term future potential of laser based light sources and summarizes, for the purpose of comparison, the characteristics and near term prospects of sources based on synchrotron radiation and free electron lasers. Conclusions are drawn on areas where the development of laser based sources is most promising and competitive in terms of applications potential.

  3. Injection seeded single mode alexandrite ring laser for lidar applications

    NASA Technical Reports Server (NTRS)

    Lee, H. Sang; Notari, Anthony

    1992-01-01

    Along with many spectroscopic applications, atmospheric lidar measurements require a tunable, narrow band laser with a very high degree of spectral purity. A standing wave pulsed alexandrite laser tuned by injection seeding with an AlGaAs laser diode has demonstrated high stability. The standing wave cavity, however, poses several difficulties in light of the single mode operation and efficient seeding beam into the cavity. In order to overcome these problems and to operate the high power alexandrite laser in a single axial mode with a high spectral purity, a new ring laser system is being developed. The design features of the ring laser and some measurements of the laser characteristics are presented.

  4. Clinical application of erbium:YAG laser in periodontology.

    PubMed

    Ishikawa, Isao; Aoki, Akira; Takasaki, Aristeo Atsushi

    2008-01-01

    Various lasers have been introduced for the treatment of oral diseases and their applications in dental clinics have become a topic of much interest among practitioners. Technological advances and improvements have increased the choices of the available laser systems for oral use. Among them, a recently developed erbium-doped:yttrium aluminum garnet (Er:YAG) laser system possesses suitable characteristics for oral soft and hard tissue ablation. Due to its high absorption in water, an effective ablation with a very thin surface interaction occurs on the irradiated tissues without any major thermal damage to the irradiated and surrounding tissues. In the field of periodontics, the application of Er:YAG laser for periodontal hard tissue has begun with studies from Japanese and German researchers. Several in vitro and clinical studies have already demonstrated an effective application of the Er:YAG laser for calculus removal and decontamination of the diseased root surface in periodontal non-surgical and surgical procedures. However, further studies are required to better understand the various effects of Er:YAG laser irradiation on biological tissues for its safe and effective application during periodontal and implant therapy. Randomized controlled clinical trials and more basic studies have to be encouraged and performed to confirm the status of Er:YAG laser treatment as an adjunct or alternative to conventional mechanical periodontal therapy. In this paper, the advantages and current clinical applications of this laser in periodontics and implant dentistry are summarized based on current scientific evidence.

  5. Diagnostic and therapeutic applications of diode lasers and solid state lasers in medicine. Progress report

    SciTech Connect

    Jacques, S.L.; Welch, A.J.; Motamedi, M.; Rastegar, S.; Tittel, F.; Esterowitz, L.

    1993-05-01

    The Texas Medical Center in Houston and the nearby UT Medical Branch at Galveston together constitute a major center of medical research activities. Laser applications in medicine are under development with the engineering assistance of the collaborating engineering enters at Rice University, UT-Austin, Texas A&M Univ. In addition, this collective is collaborating with the naval Research Laboratory, where new developments in laser design are underway, in order to transfer promising new laser technology rapidly into the medical environment.

  6. Diagnostic and therapeutic applications of diode lasers and solid state lasers in medicine

    NASA Astrophysics Data System (ADS)

    Jacques, S. L.; Welch, A. J.; Motamedi, M.; Rastegar, S.

    1992-05-01

    The Texas Medical Center in Houston and the nearby UT Medical Branch at Galveston together constitute a major center of medical research activities. Laser applications in medicine are under development with the engineering assistance of the colloborating engineering centers at Rice University, UT-Austin, and Texas A&M Univ. In addition, this collective is collaborating with the Naval Research Laboratory, where new developments in laser design are underway, in order to transfer promising new laser technology rapidly into the medical environment.

  7. Diagnostic and therapeutic applications of diode lasers and solid state lasers in medicine

    SciTech Connect

    Jacques, S.L. . Cancer Center); Welch, A.J. ); Motamedi, M. . Medical Branch); Rastegar, S. ); Tittel, F. ); Esterowitz, L. )

    1992-05-01

    The Texas Medical Center in Houston and the nearby UT Medical Branch at Galveston together constitute a major center of medical research activities. Laser applications in medicine are under development with the engineering assistance of the colloborating engineering centers at Rice University, UT-Austin, and Texas A M Univ. In addition, this collective is collaborating with the Naval Research Laboratory, where new developments in laser design are underway, in order to transfer promising new laser technology rapidly into the medical environment.

  8. Diagnostic and therapeutic applications of diode lasers and solid state lasers in medicine. Progress report

    SciTech Connect

    Jacques, S.L.; Welch, A.J.; Motamedi, M.; Rastegar, S.; Tittel, F.; Esterowitz, L.

    1992-05-01

    The Texas Medical Center in Houston and the nearby UT Medical Branch at Galveston together constitute a major center of medical research activities. Laser applications in medicine are under development with the engineering assistance of the colloborating engineering centers at Rice University, UT-Austin, and Texas A&M Univ. In addition, this collective is collaborating with the Naval Research Laboratory, where new developments in laser design are underway, in order to transfer promising new laser technology rapidly into the medical environment.

  9. Current status of clinical laser applications in periodontal therapy.

    PubMed

    Aoki, Akira; Mizutani, Koji; Takasaki, Aristeo Atsushi; Sasaki, Katia Miyuki; Nagai, Shigeyuki; Schwarz, Frank; Yoshida, Itaru; Eguro, Toru; Zeredo, Jorge Luis; Izumi, Yuichi

    2008-01-01

    Periodontal disease is a chronic inflammatory disorder caused by bacterial infection. Laser treatment demonstrates specific characteristics that may be valuable in managing periodontal disease. In addition, lasers reduce stress and uncomfortable conditions for patients during and after treatment compared to other conventional tools. This article reviews the literature to describe the current clinical applications of lasers for gingival tissue management-including esthetic treatment, non-surgical and surgical periodontal pocket therapy, osseous surgery, and implant therapy.

  10. High Power Laser Diode Arrays for 2-Micron Solid State Coherent Lidars Applications

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Meadows, Byron; Kavaya, Michael J.; Singh, Upendra; Sudesh, Vikas; Baker, Nathaniel

    2003-01-01

    Laser diode arrays are critical components of any diode-pumped solid state laser systems, constraining their performance and reliability. Laser diode arrays (LDAs) are used as the pump source for energizing the solid state lasing media to generate an intense coherent laser beam with a high spatial and spectral quality. The solid state laser design and the characteristics of its lasing materials define the operating wavelength, pulse duration, and power of the laser diodes. The pump requirements for high pulse energy 2-micron solid state lasers are substantially different from those of more widely used 1-micron lasers and in many aspects more challenging [1]. Furthermore, the reliability and lifetime demanded by many coherent lidar applications, such as global wind profiling from space and long-range clear air turbulence detection from aircraft, are beyond the capability of currently available LDAs. In addition to the need for more reliable LDAs with longer lifetime, further improvement in the operational parameters of high power quasi-cw LDAs, such as electrical efficiency, brightness, and duty cycle, are also necessary for developing cost-effective 2-micron coherent lidar systems for applications that impose stringent size, heat dissipation, and power constraints. Global wind sounding from space is one of such applications, which is the main driver for this work as part of NASA s Laser Risk Reduction Program. This paper discusses the current state of the 792 nm LDA technology and the technology areas being pursued toward improving their performance. The design and development of a unique characterization facility for addressing the specific issues associated with the LDAs for pumping 2-micron coherent lidar transmitters and identifying areas of technological improvement will be described. Finally, the results of measurements to date on various standard laser diode packages, as well as custom-designed packages with potentially longer lifetime, will be reported.

  11. Analytical application of femtosecond laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Melikechi, Noureddine; Markushin, Yuri

    2015-05-01

    We report on significant advantages provided by femtosecond laser-induced breakdown spectroscopy (LIBS) for analytical applications in fields as diverse as protein characterization and material science. We compare the results of a femto- and nanosecond-laser-induced breakdown spectroscopy analysis of dual-elemental pellets in terms of the shot-to-shot variations of the neutral/ionic emission line intensities. This study is complemented by a numerical model based on two-dimensional random close packing of disks in an enclosed geometry. In addition, we show that LIBS can be used to obtain quantitative identification of the hydrogen composition of bio-macromolecules in a heavy water solution. Finally, we show that simultaneous multi-elemental particle assay analysis combined with LIBS can significantly improve macromolecule detectability up to near single molecule per particle efficiency. Research was supported by grants from the National Science Foundation Centers of Research Excellence in Science and Technology (0630388), National Aeronautics and Space Administration (NX09AU90A). Our gratitude to Dr. D. Connolly, Fox Chase Cancer Center.

  12. Development of cryotribological theories & application to cryogenic devices. Final report

    SciTech Connect

    Iwasa, Yukikazu

    2001-03-12

    This is the final report of a research program on low-temperature friction and wear, primarily focused on development of cryotribological theories and application to cryogenic devices, particularly superconducting magnets.

  13. Diode Lasers used in Plastic Welding and Selective Laser Soldering - Applications and Products

    NASA Astrophysics Data System (ADS)

    Reinl, S.

    Aside from conventional welding methods, laser welding of plastics has established itself as a proven bonding method. The component-conserving and clean process offers numerous advantages and enables welding of sensitive assemblies in automotive, electronic, medical, human care, food packaging and consumer electronics markets. Diode lasers are established since years within plastic welding applications. Also, soft soldering using laser radiation is becoming more and more significant in the field of direct diode laser applications. Fast power controllability combined with a contactless temperature measurement to minimize thermal damage make the diode laser an ideal tool for this application. These advantages come in to full effect when soldering of increasingly small parts in temperature sensitive environments is necessary.

  14. Industrial Applications of High Power CO2 Lasers - System Descriptions

    NASA Astrophysics Data System (ADS)

    Gukelberger, Armin

    1986-10-01

    The laser as a cutting tool for sheet metal cutting has beenl well accepted in industry for many years. Several hundreds of units are used for contour cutting of small and medium-sized series on plane metal sheets up to 6 mm thick. Within the last three years, cutting systems have been expanded in three ways: thicker material up to 12 mm can now be cut by using higher powered lasers (1500 W); with the introduction of flying optic systems which cover sheet dimensions up to 4 m x 3 m, the cutting of larger sized metal sheets is possible. In addition, the use of five or six axis systems allows cutting of three-dimensional plastic and metal material. Besides laser cutting, the acceptance of systems for laser welding applications is increa sing. Several systems have been running in production for a couple of years and laser wel ding will probably become the fastest growing market in laser material processing within the next five years. The laser technology is regarded as a beneficial tool for welding, whenever low heat input and, consequently, low heat distortion is requested. To day's main welding application areas are: components of car engines and transmissions, window spacer and stainless steel tube welding, and also car body welding with laser robots or five axis gantry type systems. The output power of CO2-lasers for welding applications is between 1 and 5 kw in most cases.

  15. Scientific applications of frequency-stabilized laser technology in space

    NASA Technical Reports Server (NTRS)

    Schumaker, Bonny L.

    1990-01-01

    A synoptic investigation of the uses of frequency-stabilized lasers for scientific applications in space is presented. It begins by summarizing properties of lasers, characterizing their frequency stability, and describing limitations and techniques to achieve certain levels of frequency stability. Limits to precision set by laser frequency stability for various kinds of measurements are investigated and compared with other sources of error. These other sources include photon-counting statistics, scattered laser light, fluctuations in laser power, and intensity distribution across the beam, propagation effects, mechanical and thermal noise, and radiation pressure. Methods are explored to improve the sensitivity of laser-based interferometric and range-rate measurements. Several specific types of science experiments that rely on highly precise measurements made with lasers are analyzed, and anticipated errors and overall performance are discussed. Qualitative descriptions are given of a number of other possible science applications involving frequency-stabilized lasers and related laser technology in space. These applications will warrant more careful analysis as technology develops.

  16. [Laser applications in medicine and surgery (author's transl)].

    PubMed

    Miro, L

    After an analysis of the complex interweaving reactions of laser on biological materials, the laser applications in medicine and surgery are reviewed by the author. In ophthalmology its use is regular but not yet optimal. In otological applications the first results are good. In dermatology favorable results are obtained but the absence of special device had stopped his development. In surgery and endoscopy the best wave length must be chosen in reference to their hemostatic action and cutting, nevertheless in gastroscopy and bronchoscopy the laser seems to bring new therapeutic solutions. In odontology the pulsed lasers are dangerous for therapy but the holographic technique is a fertile research area. The author conclude to the necessary development of researches on the fundamental problems set by the biomedical applications of lasers.

  17. [Use of the thermal laser effect of laser irradiation for cardiovascular applications exemplified by the Nd:YAG laser].

    PubMed

    Ischinger, T; Coppenrath, K; Weber, H; Enders, S; Unsöld, E; Hessel, S

    1989-11-01

    Techniques of percutaneous transluminal application of laser energy for vessel recanalization have been used clinically since 1983. The commonly used Nd:YAG and argon lasers achieve ablation of atherosclerotic plaques by thermal action (vaporization). In order to reduce undesirable thermal damage in the neighborhood of the target tissue and to avoid vessel perforation, optimal irradiation parameters, modified (atraumatic) fiber tips (hot tips, sapphires), and steerable catheter systems needed to be implemented. Favorable results from peripheral application have encouraged use in the coronary circulation. More recently, coagulative tissue effects of circumferential irradiation of the vessel wall during balloon dilatation have been used for stabilization of acute and late results after mechanical balloon angioplasty. Enhancement of the differential light absorption of atherosclerotic plaque by use of biological dyes may further improve selective intravascular laser application. Intraoperative ECG-guided laser coagulation of arrhythmogenic areas of myocardium is a method for treatment of malignant arrhythmias. Transluminal non-operative application of myocardial laser photocoagulation has now been tested experimentally and shown to be safe and effective. There was no arrhythmogenicity or thermal damage of coronary arteries associated with this method. Innovative techniques such as nanosecond pulsed excimer lasers (athermal action) and development of "intelligent" lasers--which are equipped with spectroscopy-guided feedback systems for plaque recognition--have opened new perspectives and will further improve safety and efficacy of clinical laser application. However, according to current experience, the thermally acting Nd:YAG laser is an effective and versatile mode of laser therapy for selected cardiovascular indications. PMID:2532812

  18. [Use of the thermal laser effect of laser irradiation for cardiovascular applications exemplified by the Nd:YAG laser].

    PubMed

    Ischinger, T; Coppenrath, K; Weber, H; Enders, S; Unsöld, E; Hessel, S

    1989-11-01

    Techniques of percutaneous transluminal application of laser energy for vessel recanalization have been used clinically since 1983. The commonly used Nd:YAG and argon lasers achieve ablation of atherosclerotic plaques by thermal action (vaporization). In order to reduce undesirable thermal damage in the neighborhood of the target tissue and to avoid vessel perforation, optimal irradiation parameters, modified (atraumatic) fiber tips (hot tips, sapphires), and steerable catheter systems needed to be implemented. Favorable results from peripheral application have encouraged use in the coronary circulation. More recently, coagulative tissue effects of circumferential irradiation of the vessel wall during balloon dilatation have been used for stabilization of acute and late results after mechanical balloon angioplasty. Enhancement of the differential light absorption of atherosclerotic plaque by use of biological dyes may further improve selective intravascular laser application. Intraoperative ECG-guided laser coagulation of arrhythmogenic areas of myocardium is a method for treatment of malignant arrhythmias. Transluminal non-operative application of myocardial laser photocoagulation has now been tested experimentally and shown to be safe and effective. There was no arrhythmogenicity or thermal damage of coronary arteries associated with this method. Innovative techniques such as nanosecond pulsed excimer lasers (athermal action) and development of "intelligent" lasers--which are equipped with spectroscopy-guided feedback systems for plaque recognition--have opened new perspectives and will further improve safety and efficacy of clinical laser application. However, according to current experience, the thermally acting Nd:YAG laser is an effective and versatile mode of laser therapy for selected cardiovascular indications.

  19. Trends in high power laser applications in civil engineering

    NASA Astrophysics Data System (ADS)

    Wignarajah, Sivakumaran; Sugimoto, Kenji; Nagai, Kaori

    2005-03-01

    This paper reviews the research and development efforts made on the use of lasers for material processing in the civil engineering industry. Initial investigations regarding the possibility of using lasers in civil engineering were made in the 1960s and '70s, the target being rock excavation. At that time however, the laser powers available were too small for any practical application utilization. In the 1980's, the technology of laser surface cleaning of historically important structures was developed in Europe. In the early 1990s, techniques of laser surface modification, including glazing and coloring of concrete, roughening of granite stones, carbonization of wood were pursued, mainly in Japan. In the latter part of the decade, techniques of laser decontamination of concrete surfaces in nuclear facilities were developed in many countries, and field tests were caried out in Japan. The rapid advances in development of diode lasers and YAG lasers with high power outputs and efficiencies since the late 1990's have led to a revival of worldwide interest in the use of lasers for material processing in civil engineering. The authors believe that, in the next 10 years or so, the advent of compact high power lasers is likely to lead to increased use of lasers of material processing in the field of civil engineering.

  20. Solid state dye laser for medical applications

    NASA Astrophysics Data System (ADS)

    Aldag, Henry R.

    1994-06-01

    The development of solid state dye lasers could lead to a major breakthrough in the cost and compactness of a medical device. Advantages include: elimination of the flow system for the gain medium; ease with which to implement wavelength agility or the replacement of a degraded rod or sheet; and toxicity and flammability become a non-issue. Dye lasers have played a role in cardiology, dermatology, and urology. Of these cardiology is of interest to Palomar. The Palomar Model 3010 flashlamp-pumped dye laser medical device was used during phase 1 FDA clinical trials to break-up blood clots that cause heart attacks, a process known as coronary laser thrombolysis. It is the objective of this research and development effort to produce solid matrix lasers that will replace liquid dye lasers in these medical specialties.

  1. 76 FR 81518 - Notice of Issuance of Final Determination Concerning Laser-Based Multi-Function Office Machines

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-28

    ... SECURITY U.S. Customs and Border Protection Notice of Issuance of Final Determination Concerning Laser... laser-based multi-function office machines. Based upon the facts presented, CBP has concluded in the... of the laser-based multi-function office machine, and it is at their assembly and programming...

  2. Holmium laser applications of the prostate.

    PubMed

    Lerner, Lori B; Tyson, Mark D

    2009-11-01

    The high-powered holmium laser is an excellent tool for the surgical treatment of benign prostatic hyperplasia. This article discusses the background of holmium use in the prostate and describes the surgical techniques of holmium laser ablation of the prostate and holmium laser enucleation of the prostate. Operative challenges are reviewed with suggestions as to how to avoid these problems or deal with them when they arise. Surgical outcomes and a thorough literature review are both presented.

  3. Laser Material Processing for Microengineering Applications

    NASA Technical Reports Server (NTRS)

    Helvajian, H.

    1995-01-01

    The processing of materials via laser irradiation is presented in a brief survey. Various techniques currently used in laser processing are outlined and the significance to the development of space qualified microinstrumentation are identified. In general the laser processing technique permits the transferring of patterns (i.e. lithography), machining (i.e. with nanometer precision), material deposition (e.g., metals, dielectrics), the removal of contaminants/debris/passivation layers and the ability to provide process control through spectroscopy.

  4. Laser Printing for a Variety of Library Applications.

    ERIC Educational Resources Information Center

    Kelly, Glen J.

    1988-01-01

    Summarizes the current status of laser printers in terms of cost, hardware and software requirements, measurement and operational considerations, ease of use, and maintenance. The cost effectiveness of laser printing in libraries for applications such as spine labels, purchase orders, and reports, is explored. (9 notes with references) (CLB)

  5. Ophthalmic applications of ultrashort pulsed lasers

    NASA Astrophysics Data System (ADS)

    Juhasz, Tibor; Spooner, Greg; Sacks, Zachary S.; Suarez, Carlos G.; Raksi, Ferenc; Zadoyan, Ruben; Sarayba, Melvin; Kurtz, Ronald M.

    2004-06-01

    Ultrashort laser pulses can be used to create high precision incision in transparent and translucent tissue with minimal damage to adjacent tissue. These performance characteristics meet important surgical requirements in ophthalmology, where femtosecond laser flap creation is becoming a widely used refractive surgery procedure. We summarize clinical findings with femtosecond laser flaps as well as early experiments with other corneal surgical procedures such as corneal transplants. We also review laser-tissue interaction studies in the human sclera and their consequences for the treatment of glaucoma.

  6. Applications of the chemical oxygen-iodine laser

    NASA Astrophysics Data System (ADS)

    Latham, W. Pete; Kendrick, Kip R.; Quillen, Brian

    2000-01-01

    The Chemical Oxygen-Iodine Laser (COIL) has been developed at the Air Force Research Laboratory for military applications. For example, the COIL is to be use as the laser device for the ABL. A high power laser is useful for applications that require the delivery of a substantial amount of energy to a very small focused laser spot. The COIL is a member of the class of high power lasers that are also useful for industrial applications, including the materials processing task of high speed cutting and drilling. COIL technology has received considerable interest over the last several years due to its short, fiber- deliverable wavelength, scalability to very high powers, and demonstrated nearly diffraction-limited optical quality. These unique abilities make it an ideal candidate for nuclear reactor decommissioning and nuclear warhead dismantlement. Japanese researchers envision using a COIL for disaster cleanup and survivor rescue. It is also being studied by the oil and gas industry for well drilling. Any commercial or industrial application that requires very rapid, precise, and noninvasive cutting or drilling, could be readily accomplished with a COIL. Because of the substantial power levels available with a COIL, the laser could also be used for broad area applications such as paint stripping. This paper includes a collection of experiments accomplished at the Air Force Research Laboratory Chemical Laser Facility, including metal cutting, hole drilling, high power fiber optic transmission, and rock crushing.

  7. Review of soft x-ray lasers and their applications

    SciTech Connect

    Skinner, C.H.

    1991-03-01

    The emerging technology of soft x-ray lasers is in a transition phase between the first laboratory demonstrations of gain and the acceptance of soft x-ray lasers as practical tools for novel applications. Current research is focused on several fronts. The operational wavelength range has been extended to the water window'', important for applications in the life sciences. Gain has also been generated with substantially simpler technology (such as a 6J laser) and this augurs well for the commercially availability in the near future of soft x-ray lasers for a variety of applications. Advanced soft x-ray laser concepts are being developed from investigations into ultra-high intensity laser/matter interactions. The first paper a brief historical perspective of x-ray microscopy and holography have begun. In this paper a brief historical perspective of x-ray laser development will be followed by a review of recent advances in recombination, collisional and photo-pumped systems and applications. A summary of current gain-length performance achieved in laboratories worldwide is presented. Near term prospects for applications to novel fields are discussed. 81 refs., 9 figs., 1 tab.

  8. Final LDRD report : science-based solutions to achieve high-performance deep-UV laser diodes.

    SciTech Connect

    Armstrong, Andrew M.; Miller, Mary A.; Crawford, Mary Hagerott; Alessi, Leonard J.; Smith, Michael L.; Henry, Tanya A.; Westlake, Karl R.; Cross, Karen Charlene; Allerman, Andrew Alan; Lee, Stephen Roger

    2011-12-01

    We present the results of a three year LDRD project that has focused on overcoming major materials roadblocks to achieving AlGaN-based deep-UV laser diodes. We describe our growth approach to achieving AlGaN templates with greater than ten times reduction of threading dislocations which resulted in greater than seven times enhancement of AlGaN quantum well photoluminescence and 15 times increase in electroluminescence from LED test structures. We describe the application of deep-level optical spectroscopy to AlGaN epilayers to quantify deep level energies and densities and further correlate defect properties with AlGaN luminescence efficiency. We further review our development of p-type short period superlattice structures as an approach to mitigate the high acceptor activation energies in AlGaN alloys. Finally, we describe our laser diode fabrication process, highlighting the development of highly vertical and smooth etched laser facets, as well as characterization of resulting laser heterostructures.

  9. Application of Laser in Oral Surgery

    PubMed Central

    Asnaashari, Mohammad; Zadsirjan, Saeede

    2014-01-01

    In this review collected from the literature on usage of laser in oral minor surgery based on a Medline search in the time period between the years: 2008 and 2013, the most current evidence on laser-assisted oral minor surgery is going to be surveyed. PMID:25653807

  10. Laser radar for spacecraft guidance applications

    NASA Technical Reports Server (NTRS)

    Liebe, C. C.; Abramovici, A.; Bartman, R. K.; Bunker, R. L.; Chapsky, J.; Chu, C. C.; Clouse, D.; Dillon, J. W.; Hausmann, B.; Hemmati, H.; Kornfeld, R. P.; Kwa, C.; Mobasser, S.; Newell, M.; Padgett, C.; Roberts, W. T.; Spiers, G.; Warfield, Z.; Wright, M.

    2003-01-01

    A flight qualified laser radar called LAMP (LAser MaPper) is under development at JPL. LAMP is a guidance and control sensor that can form 3 dimensional images of its field of regard. This paper describes the detailed design of the LAMP sensor.

  11. Imaging systems for biomedical applications. Final report

    SciTech Connect

    Radparvar, M.

    1995-06-06

    Many of the activities of the human body manifest themselves by the presence of a very weak magnetic field outside the body, a field that is so weak that an ultra-sensitive magnetic sensor is needed for specific biomagnetic measurements. Superconducting QUantum Interference Devices (SQUIDs) are extremely sensitive detectors of magnetic flux and have been used extensively to detect the human magnetocardiogram, and magnetoencephalogram. and other biomagnetic signals. In order to utilize a SQUID as a magnetometer, its transfer characteristics should be linearized. This linearization requires extensive peripheral electronics, thus limiting the number of SQUID magnetometer channels in a practical system. The proposed digital SQUID integrates the processing circuitry on the same cryogenic chip as the SQUID magnetometer and eliminates the sophisticated peripheral electronics. Such a system is compact and cost effective, and requires minimal support electronics. Under a DOE-sponsored SBIR program, we designed, simulated, laid out, fabricated, evaluated, and demonstrated a digital SQUID magnetometer. This report summarizes the accomplishments under this program and clearly demonstrates that all of the tasks proposed in the phase II application were successfully completed with confirmed experimental results.

  12. Repetitively pulsed Cr:LiSAF laser for lidar applications

    SciTech Connect

    Shimada, Tsutomu; Early, J.W.; Lester, C.S.; Cockroft, N.J.

    1994-03-01

    A Cr:LiSAF laser has been successfully operated at time averaged powers up to 11 W and at pulse repetition rates to 12 Hz. During Q-switch operation, output energy as high as 450 mJ (32 ns FWHM) was obtained. Finally, line narrowed Q-switched pulses (< 0.1 nm) from the Cr:LiSAF laser were successfully used as a tunable light source for lidar to measure atmospheric water content.

  13. Theoretical investigations of the processes of laser interaction with ocular tissues for laser applications in ophthalmology

    NASA Astrophysics Data System (ADS)

    Pustovalov, V. K.; Jean, B.

    2006-08-01

    Theoretical investigations and the results of computer modeling of the optical, thermophysical, and thermochemical processes during laser interaction with ocular tissues are reviewed in this paper. Physical-mathematical models and results of numerical simulation of the processes are presented. The computer modeling was applied for investigations of laser heating and coagulation of ocular tissues for treatment of retina diseases and intraocular tumors, cyclophotocoagulation of the ciliary body for treatment of glaucoma, and laser thermal keratoplasty of the cornea. The influence of radiation parameters on the selectivity of laser coagulation of laminated ocular tissues is considered. The results obtained are of essential interest for laser applications in ophthalmology and can be used for investigation of heating and coagulation of tissues in different fields of laser medicine.

  14. Scientific applications for high-energy lasers

    SciTech Connect

    Lee, R.W.

    1994-03-01

    The convergence of numerous factors makes the time ripe for the development of a community of researchers to use the high-energy laser for scientific investigations. This document attempts to outline the steps necessary to access high-energy laser systems and create a realistic plan to implement usage. Since an academic/scientific user community does not exist in the USA to any viable extent, we include information on present capabilities at the Nova laser. This will briefly cover laser performance and diagnostics and a sampling of some current experimental projects. Further, to make the future possibilities clearer, we will describe the proposed next- generation high-energy laser, named for its inertial fusion confinement (ICF) goal, the multi-megaJoule, 500-teraWatt National Facility, or NIF.

  15. Advanced laser diodes for sensing applications

    SciTech Connect

    VAWTER,GREGORY A.; MAR,ALAN; CHOW,WENG W.; ALLERMAN,ANDREW A.

    2000-01-01

    The authors have developed diode lasers for short pulse duration and high peak pulse power in the 0.01--100.0 m pulsewidth regime. A primary goal of the program was producing up to 10 W while maintaining good far-field beam quality and ease of manufacturability for low cost. High peak power, 17 W, picosecond pulses have been achieved by gain switching of flared geometry waveguide lasers and amplifiers. Such high powers area world record for this type of diode laser. The light emission pattern from diode lasers is of critical importance for sensing systems such as range finding and chemical detection. They have developed a new integrated optical beam transformer producing rib-waveguide diode lasers with a symmetric, low divergence, output beam and increased upper power limits for irreversible facet damage.

  16. Femtosecond lasers in ophthalmology: clinical applications in anterior segment surgery

    NASA Astrophysics Data System (ADS)

    Juhasz, Tibor; Nagy, Zoltan; Sarayba, Melvin; Kurtz, Ronald M.

    2010-02-01

    The human eye is a favored target for laser surgery due to its accessibility via the optically transparent ocular tissue. Femtosecond lasers with confined tissue effects and minimized collateral tissue damage are primary candidates for high precision intraocular surgery. The advent of compact diode-pumped femtosecond lasers, coupled with computer controlled beam delivery devices, enabled the development of high precision femtosecond laser for ophthalmic surgery. In this article, anterior segment femtosecond laser applications currently in clinical practice and investigation are reviewed. Corneal procedures evolved first and remain dominant due to easy targeting referenced from a contact surface, such as applanation lenses placed on the eye. Adding a high precision imaging technique, such as optical coherence tomography (OCT), can enable accurate targeting of tissue beyond the cornea, such as the crystalline lens. Initial clinical results of femtosecond laser cataract surgery are discussed in detail in the latter portion part of the article.

  17. [Application of laser rays in surgery (author's transl)].

    PubMed

    Günter, H; Härb, H; Korab, W; Kyrle, P

    1979-01-01

    Some years will have to pass, until there will be evidence, if the application of laser beam in surgery of breastcancer, melanomas or basaliomas will be justified and whether it will be possible or not to interrupt or reduce intraoperative tumor cellspread. As an increasing number of surgeons have started to use laser rays in these cases of illness, results of laser surgery and those of tradional methods could be compared in a couple of years. Possibly other indications for the use of laser than those we have worked out will be outlined in general surgery. Surgeons working with laser beam may discredit the method by putting the indication not rigorusly enough. Greatest care should be taken by everybody who starts working with laser rays. Collaboration with a technician is recommended.

  18. AlGaAs laser diode FM spectrum: Phased array antenna application

    NASA Astrophysics Data System (ADS)

    Chamberland, Martin; Tetu, Michel

    Preliminary results are presented on the use of an AlGaAs laser diode to generate microwave signals suitable for application with phased array antennas. The relative intensity noise (RIN) was measured under various operating conditions to give an indication of the frequency response limitation of the laser diode. The frequency response to intensity modulation was also measured directly at microwave frequencies. Finally, the FM spectrum was observed using a heterodyne technique and compared with an empirical model. The spectrum of intensity fluctuations shows a peak near the relaxation oscillation frequency. This is a good indication of the cutoff frequency for direct current modulation of the laser diode. The behavior of the modulated laser diode is well characterized by the simultaneous intensity and frequency modulation taking into account a phase difference between the two.

  19. Spaceflight laser development for future remote sensing applications

    NASA Astrophysics Data System (ADS)

    Yu, Anthony W.; Krainak, Michael A.; Stephen, Mark A.; Abshire, James B.; Harding, David J.; Riris, Haris; Li, Steven X.; Chen, Jeffrey R.; Allan, Graham R.; Numata, Kenji; Wu, Stewart T.; Camp, Jordan B.

    2011-11-01

    At NASA's Goddard Space Flight Center we are developing next generation laser transmitters for future spaceflight, remote instruments including a micropulse altimeter for ice-sheet and sea ice monitoring, laser spectroscopic measurements of atmospheric CO2 and an imaging lidar for high resolution mapping of the Earth's surface. These laser transmitters also have applicability to potential missions to other solar-system bodies for trace gas measurements and surface mapping. In this paper we review NASA spaceflight laser transmitters used to acquire measurements in orbit around Mars, Mercury, Earth and the Moon. We then present an overview of our current spaceflight laser programs and describe their intended uses for remote sensing science and exploration applications.

  20. Clinical dental application of Er:YAG laser for Class V cavity preparation.

    PubMed

    Matsumoto, K; Nakamura, Y; Mazeki, K; Kimura, Y

    1996-06-01

    Following the development of the ruby laser by Maiman in 1960, the Nd:YAG laser, the CO2 laser, the semiconductor laser, the He-Ne laser, excimer lasers, the argon laser, and finally the Er:YAG laser capable of cutting hard tissue easily were developed and have come to be applied clinically. In the present study, the Er:YAG laser emitting at a wavelength of 2.94 microns developed by Luxar was used for the clinical preparation of class V cavities. Parameters of 8 Hz and approx. 250 mJ/pulse maximum output were used for irradiation. Sixty teeth of 40 patients were used in this clinical study. The Er:YAG laser used in this study was found to be a system suitable for clinical application. No adverse reaction was observed in any of the cases. Class V cavity preparation was performed without inducing any pain in 48/60 cases (80%). All of the 12 cases that complained of mild or severe intraoperative pain had previously complained of cervical dentin hypersensibility during the preoperative examination. Cavity preparation was completed with this laser system in 58/60 cases (91.7%). No treatment-related clinical problems were observed during the follow-up period of approx. 30 days after cavity preparation and resin filling. Cavity preparation took between approx. 10 sec and 3 min and was related more or less to cavity size and depth. Overall clinical evaluation showed no safety problem with very good rating in 49 cases (81.7%). PMID:9484088

  1. Laser-Induced Underwater Plasma And Its Spectroscopic Applications

    SciTech Connect

    Lazic, Violeta

    2008-09-23

    Applications of Laser Induced Breakdown Spectroscopy (LIBS) for analysis of immersed solid and soft materials, and for liquid impurities are described. A method for improving the LIBS signal underwater and for obtaining quantitative analyses in presence of strong shot-to-shot variations of the plasma properties is proposed. Dynamic of the gas bubble formed by the laser pulse is also discussed, together with its importance in Double-Pulse (DP) laser excitation. Results of the studies relative to an application of multi-pulse sequence and its effects on the plasma and gas bubble formation are also presented.

  2. Enabling laser applications in microelectronics manufacturing

    NASA Astrophysics Data System (ADS)

    Delmdahl, Ralph; Brune, Jan; Fechner, Burkhard; Senczuk, Rolf

    2016-02-01

    In this experimental study, we report on high-pulse-energy excimer laser drilling into high-performance build-up films which are pivotal in microelectronics manufacturing. Build-up materials ABF-GX13 from Ajinomoto as well as ZS-100 from Zeon Corporation are evaluated with respect to their viability for economic excimer laser-based micro-via formation. Excimer laser mask imaging projection at laser wavelengths of 193, 248 and 308 nm is employed to generate matrices of smaller micro-vias with different diameters and via pitches. High drilling quality is achievable for all excimer laser wavelengths with the fastest ablation rates measured in the case of 248 and 308 nm wavelengths. The presence of glass fillers in build-up films as in the ABF-GX13 material poses some limitations to the minimum achievable via diameter. However, surprisingly good drilling results are obtainable as long as the filler dimensions are well below the diameter of the micro-vias. Sidewall angles of vias are controllable by adjusting the laser energy density and pulse number. In this work, the structuring capabilities of excimer lasers in build-up films as to taper angle variations, attainable via diameters, edge-stop behavior and ablation rates will be elucidated.

  3. Silicon PV module customization using laser technology for new BIPV applications

    NASA Astrophysics Data System (ADS)

    García-Ballesteros, Juan José; Lauzurica, Sara; Morales, Miguel; del Caño, Teodosio; Valencia, Daniel; Casado, Leonardo; Balenzategui, José Lorenzo; Molpeceres, Carlos

    2014-10-01

    It is well known that lasers have helped to increase efficiency and to reduce production costs in the photovoltaic (PV) sector in the last two decades, appearing in most cases as the ideal tool to solve some of the critical bottlenecks of production both in thin film (TF) and crystalline silicon (c-Si) technologies. The accumulated experience in these fields has brought as a consequence the possibility of using laser technology to produce new Building Integrated Photovoltaics (BIPV) products with a high degree of customization. However, to produce efficiently these personalized products it is necessary the development of optimized laser processes able to transform standard products in customized items oriented to the BIPV market. In particular, the production of semitransparencies and/or freeform geometries in TF a-Si modules and standard c-Si modules is an application of great interest in this market. In this work we present results of customization of both TF a-Si modules and standard monocrystalline (m-Si) and policrystalline silicon (pc-Si) modules using laser ablation and laser cutting processes. A discussion about the laser processes parameterization to guarantee the functionality of the device is included. Finally some examples of final devices are presented with a full discussion of the process approach used in their fabrication.

  4. Aero-optics overview. [laser applications

    NASA Technical Reports Server (NTRS)

    Gilbert, K. G.

    1980-01-01

    Various aero-optical phenomena are discussed with reference to their effect on airborne high energy lasers. Major emphasis is placed on: compressibility effects induced in the surrounding flow field; viscous effects which manifests themselves as aircraft boundary layers or shear layers; inviscid flow fields surrounding the aircraft due to airflow around protuberance such as laser turret assemblies; and shocks, established whenever local flow exceeds Mach one. The significant physical parameters affecting the interaction of a laser beam with a turbulent boundary layer are also described.

  5. Laser enhanced microwave plasma isotope separation. Final report, September 30, 1992--September 29, 1995

    SciTech Connect

    Brake, M.L.; Gilgenbach, R.M.

    1996-06-01

    The experimental research was to focus on laser excitation of a low abundance isotope and then ionize and separate the isotope of low abundance using a microwave/ECR discharge at 2.45 GHz. A small compact electron cyclotron resonance ion source, which uses permanent magnets, was constructed during this project. The dye laser was purchased and later an excimer laser had to also be purchased because it turned out that the dye laser could not be pumped by our copper laser. It was intended that the dye laser be tuned to a wavelength of 670.8 nm, which would excite {sup 6}Li which would then be preferentially ionized by the ECR source and collected with a charged grid. The degree of enrichment was to be determined using thermal ionization mass spectrometry. The final objective of this project was to assess the feasibility of this system to large-scale production of stable isotopes. However the funding of this project was interrupted and we were not able to achieve all of our goals.

  6. Analytical methods of laser spectroscopy for biomedical applications

    NASA Astrophysics Data System (ADS)

    Martyshkin, Dmitri V.

    Different aspects of the application of laser spectroscopy in biomedical research have been considered. A growing demand for molecular sensing techniques in biomedical and environmental research has led the introduction of existing spectroscopic techniques, as well as development of new methods. The applications of laser-induced fluorescence, Raman scattering, cavity ring-down spectroscopy, and laser-induced breakdown spectroscopy for the monitoring of superoxide dismutase (SOD) and hemoglobin levels, the study of the characteristics of light-curing dental restorative materials, and the environmental monitoring of levels of toxic metal ion is presented. The development of new solid-state tunable laser sources based on color center crystals for these applications is presented as well.

  7. Possible application of laser isotope separation

    NASA Technical Reports Server (NTRS)

    Delionback, L. M.

    1975-01-01

    The laser isotope separation process is described and its special economic features discussed. These features are its low cost electric power operation, capital investment costs, and the costs of process materials.

  8. [The application of laser rays in gastroenterology].

    PubMed

    Platteborse, R

    1990-01-01

    After reminding the difference between the surface electro-coagulation-section and the photo-coagulation "at distance" by Laser-ray, the author underlines that the most interesting indications of the Laser-ray introduced into the digestive endoscopes are the destruction of esophageal and colonic tumors for inoperable patients or patients with operative risks. The palliative destructions avoid mutilating operations which won't increase the survival time of the patients. PMID:1701104

  9. Applications of microlens-conditioned laser diode arrays

    SciTech Connect

    Beach, R.J.; Emanuel, M.A.; Freitas, B.L.

    1995-01-01

    The ability to condition the radiance of laser diodes using shaped-fiber cylindrical-microlens technology has dramatically increased the number of applications that can be practically engaged by diode laser arrays. Lawrence Livermore National Laboratory (LLNL) has actively pursued optical efficiency and engineering improvements in this technology in an effort to supply large radiance-conditioned laser diode array sources for its own internal programs. This effort has centered on the development of a modular integrated laser diode packaging technology with the goal of enabling the simple and flexible construction of high average power, high density, two-dimensional arrays with integrated cylindrical microlenses. Within LLNL, the principal applications of microlens-conditioned laser diode arrays are as high intensity pump sources for diode pumped solid state lasers (DPSSLs). A simple end-pumping architecture has been developed and demonstrated that allows the radiation from microlens-conditioned, two-dimensional diode array apertures to be efficiently delivered to the end of rod lasers. To date, pump powers as high as 2.5 kW have been delivered to 3 mm diameter laser rods. Such high power levels are critical for pumping solid state lasers in which the terminal laser level is a Stark level lying in the ground state manifold. Previously, such systems have often required operation of the solid state gain medium at low temperature to freeze out the terminal laser Stark level population. The authors recently developed high intensity pump sources overcome this difficulty by effectively pumping to much higher inversion levels, allowing efficient operation at or near room temperature. Because the end-pumping technology is scalable in absolute power, the number of rare-earth ions and transitions that can be effectively accessed for use in practical DPSSL systems has grown tremendously.

  10. A High Energy 2-microns Laser for Multiple Lidar Applications

    NASA Technical Reports Server (NTRS)

    Yu, Jirong; Singh, Upendra N.; Barnes, James C.; Barnes, Norman P.; Petros, Mulugeta

    2000-01-01

    Solid-state 2-microns laser has been receiving considerable interest because of its eye-safe property and efficient diode pump operation, It has potential for multiple lidar applications to detect water vapor. carbon dioxide and winds. In this paper, we describe a 2-microns double pulsed Ho:Tm:YLF laser and end-pumped amplifier system. A comprehensive theoretical model has been developed to aid the design and optimization of the laser performance. In a single Q-switched pulse operation the residual energy stored in the Tm atoms will be wasted. However, in a double pulses operation mode, the residual energy stored in the Tm atoms will repopulate the Ho atoms that were depleted by the extraction of the first Q-switched pulse. Thus. the Tin sensitized Ho:YLF laser provides a unique advantage in applications that require double pulse operation, such as Differential Absorption Lidar (DIAL). A total output energy of 146 mJ per pulse pair under Q-switch operation is achieved with as high as 4.8% optical to optical efficiency. Compared to a single pulse laser, 70% higher laser efficiency is realized. To obtain high energy while maintaining the high beam quality, a master-oscillator-power-amplifier 2-microns system is designed. We developed an end-pumped Ho:Tm:YLF disk amplifier. This amplifier uses two diode arrays as pump source. A non-imaging lens duct is used to couple the radiation from the laser diode arrays to the laser disk. Preliminary result shows that the efficiency of this laser can be as high as 3%, a factor of three increases over side-pump configuration. This high energy, highly efficient and high beam quality laser is a promising candidate for use in an efficient, multiple lidar applications.

  11. Applications and mechanisms of laser tissue welding in 1995: review

    NASA Astrophysics Data System (ADS)

    Godlewski, Guilhem; Prudhomme, Michel; Tang, Jing

    1996-01-01

    For several years laser tissue welding has appeared as a new alternative technique for tissue repair instead of manual sutures. It has been evaluated in different experimental models including blood vessels, skin, nerve, intestine, bile ducts, vas and fallopian tube. Different types of lasers with different sets of parameters have been used: carbon dioxide laser, Nd:YAG laser, argon and KTP laser and diode laser. Recent trends in tissue fusion promote near infrared lasers at low irradiance with intraoperative enhancement of light absorption by specific chromophores. As far as microvascular reconstruction is concerned, successful clinical applications are currently published. Although the molecular mechanism involved in welding is not completely understood, the tissular fusion is considered as a thermal phenomena. In laser assisted microvascular anastomosis, the best experimental model, the ultrastructural examination of arteries anastomosed with Nd:YAG, argon or diode laser revealed interdigitation of collagen fibers which appeared swollen, with modified striation and organized in irregular network. The mechanism of welding involving the formation of non covalent bands between collagen strands, is generally induced by a temperature of 60 - 63 degrees Celsius well adapted to collagen denaturation.

  12. Application of reactor-pumped lasers to power beaming

    SciTech Connect

    Repetti, T.E.

    1991-10-01

    Power beaming is the concept of centralized power generation and distribution to remote users via energy beams such as microwaves or laser beams. The power beaming community is presently performing technical evaluations of available lasers as part of the design process for developing terrestrial and space-based power beaming systems. This report describes the suitability of employing a nuclear reactor-pumped laser in a power beaming system. Although there are several technical issues to be resolved, the power beaming community currently believes that the AlGaAs solid-state laser is the primary candidate for power beaming because that laser meets the many design criteria for such a system and integrates well with the GaAs photodiode receiver array. After reviewing the history and physics of reactor-pumped lasers, the advantages of these lasers for power beaming are discussed, along with several technical issues which are currently facing reactor-pumped laser research. The overriding conclusion is that reactor-pumped laser technology is not presently developed to the point of being technially or economically competitive with more mature solid-state technologies for application to power beaming. 58 refs.

  13. Laser production and heating of plasma for MHD application

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.

    1988-01-01

    Experiments have been made on the production and heating of plasmas by the absorption of laser radiation. These experiments were performed to ascertain the feasibility of using laser-produced or laser-heated plasmas as the input for a magnetohydrodynamic (MHD) generator. Such a system would have a broad application as a laser-to-electricity energy converter for space power transmission. Experiments with a 100-J-pulsed CO2 laser were conducted to investigate the breakdown of argon gas by a high-intensity laser beam, the parameters (electron density and temperature) of the plasma produced, and the formation and propagation of laser-supported detonation (LSD) waves. Experiments were also carried out using a 1-J-pulsed CO2 laser to heat the plasma produced in a shock tube. The shock-tube hydrogen plasma reached electron densities of approximately 10 to the 17th/cu cm and electron temperatures of approximately 1 eV. Absorption of the CO2 laser beam by the plasma was measured, and up to approximately 100 percent absorption was observed. Measurements with a small MHD generator showed that the energy extraction efficiency could be very large with values up to 56 percent being measured.

  14. The NASA high-power carbon dioxide laser - A versatile tool for laser applications

    NASA Technical Reports Server (NTRS)

    Lancashire, R. B.; Alger, D. L.; Manista, E. J.; Slaby, J. G.; Dunning, J. W.; Stubbs, R. M.

    1977-01-01

    The NASA Lewis Research Center has designed and fabricated a closed-cycle, continuous wave (CW), carbon dioxide (CO2) high-power laser to support research for the identification and evaluation of possible high-power laser applications. The device is designed to generate up to 70 kW of laser power in annular-shape beams from 1 to 9 cm in diameter. Electric discharge, either self-sustained or electron-beam-sustained, is used for excitation. This laser facility can be used in two ways. First, it provides a versatile tool on which research can be performed to advance the state-of-the-art technology of high-power CO2 lasers in such areas as electric excitation, laser chemistry, and quality of output beams, all of which are important whether the laser application is government or industry oriented. Second, the facility provides a well-defined, continuous wave beam for various application experiments, such as propulsion, power conversion, and materials processing.

  15. Random lasers for lab-on-chip applications

    NASA Astrophysics Data System (ADS)

    Giehl, J. M.; Butzbach, F.; Jorge, K. C.; Alvarado, M. A.; Carreño, M. N. P.; Alayo, M. I.; Wetter, N. U.

    2016-04-01

    Random lasers are laser sources in which the feedback is provided by scattering instead of reflection and which, for this reason, do not require surfaces with optical finish such as mirrors. The investigation of such lasing action in a large variety of disordered materials is a subject of high interest with very important applications such as threedimensional and speckle-free imaging, detection of cancer tissue and photonic coding and encryption. However, potential applications require optimization of random laser performance especially with respect to optical efficiency and directionality or brightness. This work demonstrates such an optimization procedure with the goal of achieving a random laser with sufficient efficiency and brightness in order to be used in practical applications. Two random lasers are demonstrated, one solid and on liquid, that fulfil directionality and efficiency requirements. The first one consists of a neodymium doped powder laser with a record slope efficiency of 1.6%. The second one is a liquid random laser injected into a HC-ARROW waveguide which uses a microchannel connected to a much larger reservoir in order to achieve the necessary directionality. Both devices can be produced by low cost fabricating technologies and easily integrated into next-generation, lab-on-chip devices used for in-situ determination of infectious tropical diseases, which is the main goal of this project.

  16. Laser materials processing applications at Lawrence Livermore National Laboratory

    SciTech Connect

    Hargrove, R.S.; Dragon, E.P.; Hackel, R.P.; Kautz, D.D.; Warner, B.E.

    1993-02-25

    High power and high radiance laser technologies developed at Lawrence Livermore National Laboratory (LLNL) such as copper-vapor lasers, solid-state slab lasers, dye lasers, harmonic wavelength conversion of these lasers, and fiber optic delivery systems show great promise for material processing tasks. Evaluation of models suggests significant potential for tenfold increases in welding, cutting, and drilling performance, as well as capability for applications in emerging technologies such as micromachining, surface treatment, and stereolithography. The goals of this program are to develop low-cost, reliable and maintainable industrial laser systems. Chains of copper lasers currently operate at more than 1.5 kW output and achieve mean time between failures of more than 1,000 hours. The beam quality of copper vapor lasers is approximately three times the diffraction limit. Dye lasers have near diffraction limited beam quality at greater than 1.0 kW. diode laser pumped, Nd:YAG slab lasers are also being developed at LLNL. Current designs achieve powers of greater than 1.0 kW and projected beam quality is in the two to five times diffraction limited range. Results from cutting and drilling studies in titanium and stainless steel alloys show that cuts and holes with extremely fine features can be made with dye and copper-vapor lasers. High radiance beams produce low distortion and small heat-affected zones. The authors have accomplished very high aspect ratio holes in drilling tests (> 60:1) and features with micron scale (5-50 {mu}m) sizes. Other, traditionally more difficult, materials such as copper, aluminum and ceramics will soon be studied in detail.

  17. Progress of laser fusion in the last 40 years and expected prosperous applications

    NASA Astrophysics Data System (ADS)

    Yamanaka, C.

    2008-05-01

    Inertial confinement fusion has remarkably developed in the last 40 years. In the 21st century, we can expect fusion energy for civilian use. We had performed two types of fusion experiments: High Temperature Demonstration and High Density Demonstration. The former experiment attained a neutron yield 1013 using the LHART target driven by the GEKKO XII laser. The latter achieved the 1000 times normal density using the random phased laser beams which realized the Edward Teller proposal of IQEC 1972. Now, the FIREX project to explore fast ignition is going on. The heating process of energetic electrons as well as ions is a key issue of the fast ignition. Investigation on the extreme condition of plasma in high density and high temperature which are introduced by the PW laser give us a new field of nuclear science. On the way to the final fusion goal, we can expect various fruits in the field of high power laser applications, such as laser-induced nuclear reaction, EUV light source for lithography, nuclear transmutation, laser astrophysics, medical application of particle beam and so on.

  18. The development of novel Ytterbium fiber lasers and their applications

    NASA Astrophysics Data System (ADS)

    Nie, Bai

    The aim of my Ph.D. research is to push the fundamental limits holding back the development of novel Yb fiber lasers with high pulse energy and short pulse duration. The purpose of developing these lasers is to use them for important applications such as multiphoton microscopy and laser-induced breakdown spectroscopy. My first project was to develop a short-pulse high-energy ultrafast fiber laser for multiphoton microscopy. To achieve high multiphoton efficiency and depth resolved tissue imaging, ultrashort pulse duration and high pulse energy are required. In order to achieve this, an all-normal dispersion cavity design was adopted. Output performances of the built lasers were investigated by varying several cavity parameters, such as pump laser power, fiber length and intra-cavity spectral filter bandwidth. It was found that the length of the fiber preceding the gain fiber is critical to the laser performance. Generally, the shorter the fiber is, the broader the output spectrum is. The more interesting parameter is the intra-cavity spectral filter bandwidth. Counter intuitively, laser cavities using narrower bandwidth spectral filters generated much broader spectra. It was also found that fiber lasers with very narrow spectral filters produced laser pulses with parabolic profile, which are referred to as self-similar pulses or similaritons. This type of pulse can avoid wave-breaking and is an optimal approach to generate pulses with high pulse energy and ultrashort pulse duration. With a 3nm intra-cavity spectral filter, output pulses with about 20 nJ pulse energy were produced and compressed to about 41 fs full-width-at-half-maximum (FWHM) pulse duration. Due to the loss in the compression device, the peak power of the compressed pulses is about 250 kW. It was the highest peak power generated from a fiber oscillator when this work was published. This laser was used for multiphoton microscopy on living tissues like Drosophila larva and fruit fly wings. Several

  19. Medical Applications Of CO2 Laser Fiber Optics

    NASA Astrophysics Data System (ADS)

    McCord, R. C.

    1981-07-01

    In 1978, Hughes Laboratories reported development of fiber optics that were capable of transmitting CO2 laser energy. These fibers are now being tested for medical applications. Wide ranging medical investigation with CO2 lasers has occurred during the twelve years since the first observations of laser hemostasis. Specialists in ophthalmology, neurosurgery, urology, gynecology, otolaryngology, maxillo-facial/plastic surgery, dermatology, and oncology among others, have explored its use. In principle, all these specialists use CO2 laser radiation at 10.6 microns to thermally destroy diseased tissues. As such, CO2 lasers compare and compete with electrosurgical devices. The fundamental difference between these modalities lies in how they generate heat in treated tissue.

  20. Optimized laser application in dermatology using infrared thermography

    NASA Astrophysics Data System (ADS)

    Thomas, Roderick A.; Donne, Kelvin E.; Clement, Marc; Kiernan, Michael N.

    2002-03-01

    Infrared thermography can be used to optimize the application of lasers in dermatology with particular reference to the treatment of certain skin disorders such as vascular lesions and depilation. The efficacy of treatment is dependent upon a number of factors including: Optimization and correct selection of laser parameters such as wavelength and spot size. Human factors, such as laser operator skill, patient's skin type and anatomical location. By observing the thermal effects of laser irradiation on the skins surface during treatment results in improved efficacy and minimizes the possible threshold to skin damage, reducing the possibility of burning and scarring. This is of particular significance for example, in the control of purpura for the treatment of vascular lesions. The optimization is validated with reference to a computer model that predicts various skin temperatures based on two different laser spot sizes.

  1. Applications of absorption spectroscopy using quantum cascade lasers.

    PubMed

    Zhang, Lizhu; Tian, Guang; Li, Jingsong; Yu, Benli

    2014-01-01

    Infrared laser absorption spectroscopy (LAS) is a promising modern technique for sensing trace gases with high sensitivity, selectivity, and high time resolution. Mid-infrared quantum cascade lasers, operating in a pulsed or continuous wave mode, have potential as spectroscopic sources because of their narrow linewidths, single mode operation, tunability, high output power, reliability, low power consumption, and compactness. This paper reviews some important developments in modern laser absorption spectroscopy based on the use of quantum cascade laser (QCL) sources. Among the various laser spectroscopic methods, this review is focused on selected absorption spectroscopy applications of QCLs, with particular emphasis on molecular spectroscopy, industrial process control, combustion diagnostics, and medical breath analysis. PMID:25239063

  2. [Application of laser rays in surgery (author's transl)].

    PubMed

    Günter, H; Korab, W; Kyrle, P

    1978-09-01

    Some years will have to pass, until there will be evidence, if application of leaser beam in surgery of Breastcancer, Melanomas or Basaliomas was justified and whether it is possible or not to interrupt or reduce intraoperative tumor cellspread. As an increasing number of surgeons have started to use laser rays in these illnesses, result of laser surgery and those of traditional methods could be compared in a couple of years. Possibly other indications will be outlined in general surgery for the use of laser beside those we have been working out. It may happen that surgeons working with laser beam might bring the method into discredit putting indication not rigorous enough. I should like to remind everybody who starts working with laser rays, to do so with greatest possible care. Collaboration with a technician is recommended. Periodic he should control the machine and handle arising technical problems.

  3. Laser-Induced Breakdown Spectroscopy (LIBS): specific applications

    NASA Astrophysics Data System (ADS)

    Trtica, M. S.; Savovic, J.; Stoiljkovic, M.; Kuzmanovic, M.; Momcilovic, M.; Ciganovic, J.; Zivkovic, S.

    2015-12-01

    A short overview of Laser Induced Breakdown Spectroscopy (LIBS) with emphasis on the new trends is presented. Nowadays, due to unique features of this technique, LIBS has found applications in a great variety of fields. Achievements in the application of LIBS in nuclear area, for hazardous materials detection and in geology were considered. Also, some results recently obtained at VINCA Institute, with LIBS system based on transversely excited atmospheric (TEA) CO2 laser, are presented. Future investigations of LIBS will be oriented toward further improvement of the analytical performance of this technique, as well as on finding new application fields.

  4. Optofluidic Bio-Lasers: Concept and Applications

    PubMed Central

    Fan, Xudong; Yun, Seok-Hyun

    2014-01-01

    An optofluidic bio-laser integrates biological materials into the gain medium while forming an optical cavity in the fluidic environment, either on a microfluidic chip or within a biological system. The laser emission has characteristics fundamentally different from conventional fluorescence emission. It can be highly sensitive to a specific molecular change in the gain medium as the light-matter interaction is amplified by the resonance in the cavity. The enhanced sensitivity can be used to probe and quantify the underlying biochemical and biological processes in vitro in a microfluidic device, in situ in a cell (cytosol), or in vivo in a live organism. Here we describe the principle of the optofluidic bio-laser, review its recent progress and provide an outlook of this emerging technology. PMID:24481219

  5. Applications of the 308-nm excimer laser in dermatology

    NASA Astrophysics Data System (ADS)

    Farkas, A.; Kemeny, L.

    2006-05-01

    Excimer lasers contain a mixture of a noble inert gas and a halogen, which form excited dimers only in the activated state. High-energy current is used to produce these dimers, which have a very short lifetime, and after their fast dissociation they release the excitation energy through ultraviolet photons. The application of these lasers proved to be successful in medicine, including the field of ophthalmology, cardiology, angiology, dentistry, orthopaedics, and, in recent years, dermatology. For medical purposes, the 193-nm argon fluoride, the 248-nm krypton fluoride, the 351-nm xenon fluoride, and the 308-nm xenon chloride lasers are used. Recently, the 308-nm xenon chloride laser has gained much attention as a very effective treatment modality in dermatological disorders. It was successfully utilized in psoriasis; later, it proved to be useful in handling other lightsensitive skin disorders and even in the treatment of allergic rhinitis. This review summarizes the possible applications of this promising tool in dermatology.

  6. Nuclear-driven flashlamp pumping of the atomic iodine laser. Final report

    SciTech Connect

    Miley, G.H.

    1992-03-01

    This report is a study of the atomic iodine laser pumped with nuclear- excited XeBr fluorescence. Preliminary experiments, conducted in the TRIGA reactor investigated the fluorescence of the excimer XeBr under nuclear pumping with {sup 10}B and {sup 3}He, for use as a flashlamp gas to stimulate the laser. These measurements included a determination of the fluorescence efficiency (light emitted in the wavelength region of interest, divided by energy deposited in the gas) of XeBr under nuclear pumping, with varying excimer mixtures. Maximum fluorescence efficiencies were approximately 1%. In order to better understand XeBr under nuclear excitation, a kinetics model of the system was prepared. The model generated the time-dependant concentrations of 20 reaction species for three pulse sizes, a TRIGA pulse, a fast burst reactor pulse, and an e-beam pulse. The modeling results predicted fluorescence efficiencies significantly higher (peak efficiencies of approximately 10%) than recorded in the fluorescence experiments. The cause of this discrepancy was not fully determined. A ray tracing computer model was also prepared to evaluate the efficiency with which nuclear-induced fluorescence generated in one cavity of a laser could be coupled into another cavity containing an iodine lasant. Finally, an experimental laser cell was constructed to verify that nuclear-induced XeBr fluorescence could be used to stimulate a laser. Lasing was achieved at 1.31 micron in the TRIGA using C{sub 3}F{sub 7}I, a common iodine lasant. Peak laser powers were approximately 20 mW. Measured flashlamp pump powers at threshold agreed well with literature values, as did lasant pressure dependency on laser operation.

  7. Facet joint laser radiation: tissue effects of a new clinical laser application

    NASA Astrophysics Data System (ADS)

    Werkmann, Klaus; Thal, Dietmar R.

    1996-01-01

    Chronic unilateral and bilateral back pain with pseudoradicular symptoms, is a common clinical syndrome, which in many cases can be related to the facet joint syndrome. The pain is caused by mechanical affection of synovial and capsular nerve terminals. Therefore, current therapeutical attempts including physical therapy, intra-articular injection of local anesthetics and steroids and thermocoagulation of the facet joint with a thermocoagulator, are performed. We confirmed laser coagulation of the facet joint. Porcine cadaveric spines were treated immediately after death by intra-articular facet joint laser radiation. With the pulsed Nd:YAG laser (1064 nm) altogether 600 J were applied in three different places 4 mm apart at the top of the facet joint. The results showed that facet joint laser radiation leads to a small (about 1 - 2 mm diameter) lesion restricted to the facet joint cavity and its synovia. Histologically, we found a central carbonization zone and necrosis, including almost the whole cartilage and approximately 0.2 mm of the adjacent bone. These changes are similar to Nd:Yag-laser applications in other skeletal regions. It is suggested that these changes may lead to facet joint denervation by coagulation of the synovial nerve terminals. Cicatration of the laser lesion might cause ankylosis of this joint. In sum, facet joint laser radiation could be an alternative therapeutical tool for lower back pain of the facet joint syndrome type. Therefore, future clinical application of this technique seems to be very promising.

  8. Temporal Characterization of a Picosecond Laser-Pumped X-ray Laser (for Applications)

    SciTech Connect

    Dunn, J; Nilsen, J; Shepherd, R; Shlyaptsev, V; Booth, R; Smith, R; Hunter, J

    2003-11-25

    Compact soft x-ray laser sources are now used routinely for various applications primarily because of their high repetition rate, high photon fluence and short pulse duration characteristics. For some of these applications, for example interferometry of high density laser-produced plasmas, longer optical drive pulses, 6-13 ps (FWHM), have been implemented to maximize the x-ray output and coherence. It is therefore important to know the x-ray laser pulse length, shape and repeatability for these specific experiments as a baseline measurement but also to better understand the temporal behavior as a function of the pumping conditions in general. We report a detailed temporal characterization of the picosecond-driven 14.7 nm Ni-like Pd ion x-ray laser on the Compact Multipulse Terawatt (COMET) laser at LLNL using an ultrafast x-ray streak camera measurement of a horizontal slice of the near-field x-ray laser pattern. This is measured as a function of the chirped pulse amplification pumping laser conditions, including varying the pump pulse from 0.5-27 ps (FWHM), varying the plasma column length as well as investigating traveling wave (TW) and non-TW irradiation conditions.

  9. Industrial multibeam lasers and their technological applications

    NASA Astrophysics Data System (ADS)

    Bukhanova, I. F.; Zhuravel, V. M.; Divinsky, V. V.

    1994-04-01

    A variety of industrial technological laser systems with 1.5, 2.5 - 3.5, 8 - 10 kW power have been developed around the multibeam diffusion-cooled CO2 lasers. A number of technological processes of parts hardening and reconditioning (sleeves made in cast iron, cylinder of diesel locomotive engines, crankshafts and camshafts of tractor engines, parts of car and tractor running gears, rings of drilling bearings, lead screws, machine guides), that employ the LTS have been developed and introduced at various industries.

  10. Catadioptric optics for laser Doppler velocimeter applications

    NASA Technical Reports Server (NTRS)

    Dunagan, Stephen E.

    1989-01-01

    This paper examines the adaptation of low-cost Schmidt-Cassegrain astronomical telescopes to perform the laser-beam-focusing and scattered-light collection tasks associated with dual-beam laser Doppler velocimetry. A generic telescope design is analyzed using ray-tracing methods and Gaussian beam-propagation theory. A straightforward modification procedure to convert from infinite to near unity conjugate-ratio operation with very low residual aberration is identified and tested with a 200-mm-aperture telescope modified for f/10 operation. Performance data for this modified telescope configuration are near the diffraction limit and agree well with predictions.

  11. Innovative lasers for uranium isotope separation. Final report, September 1, 1989--April 1, 1993

    SciTech Connect

    Brake, M.L.; Gilgenbach, R.M.

    1993-07-01

    Copper vapor laser have important applications to uranium atomic vapor laser isotope separation (AVLIS). We have investigated two innovative methods of exciting/pumping copper vapor lasers which have the potential to improve the efficiency and scaling of large laser systems used in uranium isotope separation. Experimental research has focused on the laser discharge kinetics of (1) microwave, and (2) electron beam excitation/pumping of large-volume copper vapor lasers. Microwave resonant cavity produced copper vapor plasmas at 2.45 GHz, have been investigated in three separate experimental configurations. The first examined the application of CW (0-500W) power and was found to be an excellent method for producing an atomic copper vapor from copper chloride. The second used a pulsed (5kW, 0.5--5 kHz) signal superimposed on the CW signal to attempt to produce vaporization, dissociation and excitation to the laser states. Enhanced emission of the optical radiation was observed but power densities were found to be too low to achieve lasing. In a third experiment we attempted to increase the applied power by using a high power magnetron to produce 100 kW of pulsed power. Unfortunately, difficulties with the magnetron power supply were encountered leaving inconclusive results. Detailed modeling of the electromagnetics of the system were found to match the diagnostics results well. An electron beam pumped copper vapor system (350 kV, 1.0 kA, 300 ns) was investigated in three separate copper chloride heating systems, external chamber, externally heated chamber and an internally heated chamber. Since atomic copper spectral lines were not observed, it is assumed that a single pulse accelerator is not capable of both dissociating the copper chloride and exciting atomic copper and a repetitively pulsed electron beam generator is needed.

  12. Laser induced breakdown spectroscopy application in joint European torus

    NASA Astrophysics Data System (ADS)

    Semerok, A.; L'Hermite, D.; Weulersse, J.-M.; Lacour, J.-L.; Cheymol, G.; Kempenaars, M.; Bekris, N.; Grisolia, C.

    2016-09-01

    The results on the first successful application of Laser Induced Breakdown Spectroscopy (LIBS) for remote in situ diagnostics of plasma facing components (a deposited layer on a divertor tile) in Joint European Torus (JET) are presented. The studies were performed with an available JET EDGE LIDAR laser system. For in-depth analysis of deposited layers on JET divertor tiles, a number of laser shots were applied onto the same divertor place without laser beam displacement. The spectral lines of D, CII and impurity elements (CrI, BeII, …) were identified in a wide spectral range (400-670 nm). With the increase in a number of laser shots applied onto the same divertor place, we observed consecutive changes in spectral line intensities of deuterium, carbon, and impurities with the appearance of spectral lines of tungsten substrate (WI). In-depth analysis of deposited layers on JET divertor tiles was made on the basis of the spectral line behaviour in reference to the applied laser shots. The possibility of surface cartography with laser beam displacement on the tile surface was demonstrated as well. Based on the results obtained, we may conclude that LIBS method is applicable for in situ remote analysis of deposited layers of JET plasma facing components.

  13. Advances in 193 nm excimer lasers for mass spectrometry applications

    NASA Astrophysics Data System (ADS)

    Delmdahl, Ralph; Esser, Hans-Gerd; Bonati, Guido

    2016-03-01

    Ongoing progress in mass analysis applications such as laser ablation inductively coupled mass spectrometry of solid samples and ultraviolet photoionization mediated sequencing of peptides and proteins is to a large extent driven by ultrashort wavelength excimer lasers at 193 nm. This paper will introduce the latest improvements achieved in the development of compact high repetition rate excimer lasers and elaborate on the impact on mass spectrometry instrumentation. Various performance and lifetime measurements obtained in a long-term endurance test over the course of 18 months will be shown and discussed in view of the laser source requirements of different mass spectrometry tasks. These sampling type applications are served by excimer lasers delivering pulsed 193 nm output of several mJ as well as fast repetition rates which are already approaching one Kilohertz. In order to open up the pathway from the laboratory to broader market industrial use, sufficient component lifetimes and long-term stable performance behavior have to be ensured. The obtained long-term results which will be presented are based on diverse 193 nm excimer laser tube improvements aiming at e.g. optimizing the gas flow dynamics and have extended the operational life the laser tube for the first time over several billion pulses even under high duty-cycle conditions.

  14. Novel diode laser-based sensors for gas sensing applications

    NASA Technical Reports Server (NTRS)

    Tittel, F. K.; Lancaster, D. G.; Richter, D.

    2000-01-01

    The development of compact spectroscopic gas sensors and their applications to environmental sensing will be described. These sensors employ mid-infrared difference-frequency generation (DFG) in periodically poled lithium niobate (PPLN) crystals pumped by two single-frequency solid state lasers such as diode lasers, diode-pumped solid state, and fiber lasers. Ultrasensitive, highly selective, and real-time measurements of several important atmospheric trace gases, including carbon monoxide, nitrous oxide, carbon dioxide, formaldehyde [correction of formaldehye], and methane, have been demonstrated.

  15. Application of G criterion in metal vapor ion laser

    NASA Astrophysics Data System (ADS)

    Gang, Chen; Bailiang, Pan; Yi, Jin; Kun, Chen; Zhixin, Yao

    2003-09-01

    Application of G criterion to efficient operation of pulsed discharge-excited R-M transition metal vapor laser was successfully extended to univalent ionic lasing medium from neutral atomic lasing medium on the basis of analyzing the simulation results of 1.09 μm Sr + lasing process. All of the known 17 R-M transition laser lines of univalent ions follow the G criterion except one, to which an interpretation is given. Furthermore, we suggest that only 69 lines among 212 possible R-M transition laser lines predicted by S.V. Markova, which satisfy the G criterion, should be explored first.

  16. Indium phosphide solar cells for laser power beaming applications

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, Geoffrey A.

    1992-01-01

    Lasers can be used to transmit power to photovoltaic cells. Solar cell efficiencies are enhanced significantly under monochromatic light, and therefore a laser beam of proper wavelength could be a very effective source of illumination for a solar array operating at very high efficiencies. This work reviews the modeling studies made on indium phosphide solar cells for such an application. These cells are known to be very radiation resistant and have a potential for high efficiency. Effects of cell series resistance, laser intensity, and temperature on cell performance have been discussed.

  17. Biological applications of ultraviolet free-electron lasers

    SciTech Connect

    Sutherland, J.C.

    1997-10-01

    This review examines the possibilities for biological research using the three ultraviolet free-electron lasers that are nearing operational status in the US. The projected operating characteristics of major interest in biological research of the free-electron lasers at Brookhaven National Laboratory, the Thomas Jefferson National Accelerator Facility, and Duke University are presented. Experimental applications in the areas of far- and vacuum ultraviolet photophysics and photochemistry, structural biology, environmental photobiology, and medical research are discussed and the prospects for advances in these areas, based upon the characteristics of the new ultraviolet free-electron lasers, are evaluated.

  18. Tailoring Laser Propulsion for Future Applications in Space

    SciTech Connect

    Eckel, Hans-Albert; Scharring, Stefan

    2010-10-08

    Pulsed laser propulsion may turn out as a low cost alternative for the transportation of small payloads in future. In recent years DLR investigated this technology with the goal of cheaply launching small satellites into low earth orbit (LEO) with payload masses on the order of 5 to 10 kg. Since the required high power pulsed laser sources are yet not at the horizon, DLR focused on new applications based on available laser technology. Space-borne, i.e. in weightlessness, there exist a wide range of missions requiring small thrusters that can be propelled by laser power. This covers space logistic and sample return missions as well as position keeping and attitude control of satellites.First, a report on the proof of concept of a remote controlled laser rocket with a thrust vector steering device integrated in a parabolic nozzle will be given. Second, the road from the previous ground-based flight experiments in earth's gravity using a 100-J class laser to flight experiments with a parabolic thruster in an artificial 2D-zero gravity on an air cushion table employing a 1-J class laser and, with even less energy, new investigations in the field of laser micro propulsion will be reviewed.

  19. Power blue and green laser diodes and their applications

    NASA Astrophysics Data System (ADS)

    Hager, Thomas; Strauß, Uwe; Eichler, Christoph; Vierheilig, Clemens; Tautz, Sönke; Brüderl, Georg; Stojetz, Bernhard; Wurm, Teresa; Avramescu, Adrian; Somers, André; Ristic, Jelena; Gerhard, Sven; Lell, Alfred; Morgott, Stefan; Mehl, Oliver

    2013-03-01

    InGaN based green laser diodes with output powers up to 50mW are now well established for variety of applications ranging from leveling to special lighting effects and mobile projection of 12lm brightness. In future the highest market potential for visible single mode profile lasers might be laser projection of 20lm. Therefore direct green single-mode laser diodes with higher power are required. We found that self heating was the limiting factor for higher current operation. We present power-current characteristics of improved R and D samples with up to 200mW in cw-operation. An optical output power of 100mW is reached at 215mA, a current level which is suitable for long term operation. Blue InGaN laser diodes are also the ideal source for phosphor based generation of green light sources of high luminance. We present a light engine based on LARP (Laser Activated Remote Phosphor) which can be used in business projectors of several thousand lumens on screen. We discuss the advantages of a laser based systems in comparison with LED light engines. LARP requires highly efficient blue power laser diodes with output power above 1W. Future market penetration of LARP will require lower costs. Therefore we studied new designs for higher powers levels. R and D chips with power-current characteristics up to 4W in continuous wave operation on C-mount at 25°C are presented.

  20. Laser cleaning of metal surfaces: physical processes and applications

    NASA Astrophysics Data System (ADS)

    Veiko, V. P.; Mutin, T. J.; Smirnov, V. N.; Shakhno, E. A.; Batishche, S. A.

    2008-01-01

    Physical processes occurring by laser cleaning of metal surfaces from soiling particles, coatings and near-surface oxide or corroded layer are considered. Unconventional methods of laser cleaning which promote increasing the quality and effectiveness of cleaning and solving of the problem of soiling substance gathering are proposed. Applications of these methods in a number of novel fields, such as pinholes cleaning, coatings removal, radioactive contaminated layers removal, cleaning of objects of historic and cultural heritage are considered.

  1. Laser Induced Breakdown Spectroscopy:. AN Application on Multilayered Archeological Ceramics

    NASA Astrophysics Data System (ADS)

    Ponterio, R.; Trusso, S.; Vasi, C.; Aragona, S.; Mavilia, L.

    2004-10-01

    In this work we show an example of application of Laser Induced Breakdown Spectroscopy (LIBS) in combination with another laser-based technique: Raman micro-spectroscopy for the identification of pigments and glaze on pottery found archaeological excavations in Amendolea castle site (south of Italy in Calabrian peninsula); the objects belong to medieval period. The spectral data indicates the qualitative elemental composition of the examined materials and, in addition, give us useful information on the stratigraphy of the paint layers.

  2. Nonlinear wideband optical filters for laser protection applications

    NASA Astrophysics Data System (ADS)

    Donval, Ariela; Golding, Karin; Nevo, Doron; Fisher, Tali; Lipman, Ofir; Oron, Moshe

    2012-02-01

    With the development of more powerful lasers for applications, optical limiters and blockers are required for providing human eye and optical sensors protection. We report on passive optical power control devices based on a range of photonic nanostructures, including mainly nanostructures for spatial field localization to enhance optical nonlinearities. We present the two main optical power control mechanisms: blocking and limiting, as well as their corresponding nanoscale phenomena. We propose a dynamic protection to cameras, sensors and the human eye from laser threats.

  3. Diffraction Gratings for High-Intensity Laser Applications

    SciTech Connect

    Britten, J

    2008-01-23

    The scattering of light into wavelength-dependent discrete directions (orders) by a device exhibiting a periodic modulation of a physical attribute on a spatial scale similar to the wavelength of light has been the subject of study for over 200 years. Such a device is called a diffraction grating. Practical applications of diffraction gratings, mainly for spectroscopy, have been around for over 100 years. The importance of diffraction gratings in spectroscopy for the measurement of myriad properties of matter can hardly be overestimated. Since the advent of coherent light sources (lasers) in the 1960's, applications of diffraction gratings in spectroscopy have further exploded. Lasers have opened a vast application space for gratings, and apace, gratings have enabled entirely new classes of laser systems. Excellent reviews of the history, fundamental properties, applications and manufacturing techniques of diffraction gratings up to the time of their publication can be found in the books by Hutley (1) and more recently Loewen and Popov (2). The limited scope of this chapter can hardly do justice to such a comprehensive subject, so the focus here will be narrowly limited to characteristics required for gratings suitable for high-power laser applications, and methods to fabricate them. A particular area of emphasis will be on maximally-efficient large-aperture gratings for short-pulse laser generation.

  4. Final report: Compiled MPI. Cost-Effective Exascale Application Development

    SciTech Connect

    Gropp, William Douglas

    2015-12-21

    This is the final report on Compiled MPI: Cost-Effective Exascale Application Development, and summarizes the results under this project. The project investigated runtime enviroments that improve the performance of MPI (Message-Passing Interface) programs; work at Illinois in the last period of this project looked at optimizing data access optimizations expressed with MPI datatypes.

  5. Space Applications of Industrial Laser Systems (SAILS)

    NASA Technical Reports Server (NTRS)

    Mueller, Robert E.; McCay, T. Dwayne; McCay, Mary Helen; Bible, Brice

    1992-01-01

    A program is under way to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. The system will be capable of cutting and welding steel, aluminum and Inconel alloys of the type planned for use on the Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1995, will be constructed as two modules to fit into standard Get Away Special (GAS) canisters. The first can holds the laser and its power supply, to be constructed by our industrial partner, Lumonics Industrial Processing Division. The second canister has the materials processing workstation and the command and data acquisition subsystems. These components will be provided by groups at UTSI and the University of Waterloo. The cans are linked by a fiber-optic cable which transmits the beam from the laser head to the workstation.

  6. Space Applications of Industrial Laser Systems (SAILS)

    NASA Technical Reports Server (NTRS)

    Mueller, Robert E.; McCay, T. Dwayne; McCay, Mary Helen; Bible, Brice

    1995-01-01

    A program is under way to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. The system will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use on Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1995, will be constructed as two modules to fit into the standard Get Away Special (GAS) canisters. The first can holds the laser and its power supply, to be constructed by our industrial partner, Lumonics Industrial Processing Division. The second canister has the materials processing workstation and the command and data acquisition subsystems. These components will be provided by groups at the University of Tennessee Space Institute (UTSI) and the University of Waterloo. The cans are linked by a fiber-optic cable which transmits the beam from the laser head to the workstation.

  7. Dye system for dye laser applications

    SciTech Connect

    Hammond, P.R.

    1991-05-21

    This patent describes a dye of the DCM family, (2-methyl-6-(2-(1,2,3,4-tetrahydro-1-methyl-6-quinolinyl)ethenyl)-4H-pyran-4-ylidene)-propanedinitrile, dissolved in 2-phenoxyethanol, is non-mutagenic, stable and efficient, particularly in a pumped continuous wave laser system.

  8. Dye system for dye laser applications

    DOEpatents

    Hammond, Peter R.

    1991-01-01

    A dye of the DCM family, [2-methyl-6-[2-(1,2,3,4-tetrahydro-1-methyl-6-quinolinyl)ethenyl]-4H-pyran -4-ylidene]-propanedinitrile, dissolved in 2-phenoxyethanol, is non-mutagenic, stable and efficient, particularly in a pumped continuous wave laser system.

  9. Laser mass spectrometry for DNA fingerprinting for forensic applications

    SciTech Connect

    Chen, C.H.; Tang, K.; Taranenko, N.I.; Allman, S.L.; Chang, L.Y.

    1994-12-31

    The application of DNA fingerprinting has become very broad in forensic analysis, patient identification, diagnostic medicine, and wildlife poaching, since every individual`s DNA structure is identical within all tissues of their body. DNA fingerprinting was initiated by the use of restriction fragment length polymorphisms (RFLP). In 1987, Nakamura et al. found that a variable number of tandem repeats (VNTR) often occurred in the alleles. The probability of different individuals having the same number of tandem repeats in several different alleles is very low. Thus, the identification of VNTR from genomic DNA became a very reliable method for identification of individuals. DNA fingerprinting is a reliable tool for forensic analysis. In DNA fingerprinting, knowledge of the sequence of tandem repeats and restriction endonuclease sites can provide the basis for identification. The major steps for conventional DNA fingerprinting include (1) specimen processing (2) amplification of selected DNA segments by PCR, and (3) gel electrophoresis to do the final DNA analysis. In this work we propose to use laser desorption mass spectrometry for fast DNA fingerprinting. The process and advantages are discussed.

  10. High-power diode lasers and their direct industrial applications

    NASA Astrophysics Data System (ADS)

    Loosen, Peter; Treusch, Hans-Georg; Haas, C. R.; Gardenier, U.; Weck, Manfred; Sinnhoff, V.; Kasperowski, S.; vor dem Esche, R.

    1995-04-01

    The paper summarizes activities of the two Fraunhofer-Institutes ILT and IPT concerning the development of high-power laser-diode stacks and their direct industrial applications. With microchannel coolers in copper technology and ultra-precision machined micro-optics a stack of 330 - 400 W total power with a maximum intensity of the focused beam of 2 104 W/cm2 has been built and tested in first applications. By further improvements of the lens-fabrication and -alignment technology as well as increase of the number of stacked diodes an output power in the kW-range and intensities up to about 105 W/cm2 shall be achieved in the near future. Applications of such laser sources in surface technology, in the processing of plastics, in laser-assisted machining and in brazing are discussed.

  11. Applications of laser wakefield accelerator-based light sources

    NASA Astrophysics Data System (ADS)

    Albert, Félicie; Thomas, Alec G. R.

    2016-11-01

    Laser-wakefield accelerators (LWFAs) were proposed more than three decades ago, and while they promise to deliver compact, high energy particle accelerators, they will also provide the scientific community with novel light sources. In a LWFA, where an intense laser pulse focused onto a plasma forms an electromagnetic wave in its wake, electrons can be trapped and are now routinely accelerated to GeV energies. From terahertz radiation to gamma-rays, this article reviews light sources from relativistic electrons produced by LWFAs, and discusses their potential applications. Betatron motion, Compton scattering and undulators respectively produce x-rays or gamma-rays by oscillating relativistic electrons in the wakefield behind the laser pulse, a counter-propagating laser field, or a magnetic undulator. Other LWFA-based light sources include bremsstrahlung and terahertz radiation. We first evaluate the performance of each of these light sources, and compare them with more conventional approaches, including radio frequency accelerators or other laser-driven sources. We have then identified applications, which we discuss in details, in a broad range of fields: medical and biological applications, military, defense and industrial applications, and condensed matter and high energy density science.

  12. LDRD Final Report for''Tactical Laser Weapons for Defense'' SI (Tracking Code 01-SI-011)

    SciTech Connect

    Beach, R; Zapata, L

    2002-01-30

    The focus of this project was a convincing demonstration of two new technological approaches to high beam quality; high average power solid-state laser systems that would be of interest for tactical laser weapon applications. Two pathways had been identified to such systems that built on existing thin disk and fiber laser technologies. This SI was used as seed funding to further develop and vet these ideas. Significantly, the LLNL specific enhancements to these proposed technology paths were specifically addressed for devising systems scaleable to the 100 kW average power level. In the course of performing this work we have established an intellectual property base that protects and distinguishes us from other competitive approaches to the same end.

  13. A NASA high-power space-based laser research and applications program

    NASA Technical Reports Server (NTRS)

    Deyoung, R. J.; Walberg, G. D.; Conway, E. J.; Jones, L. W.

    1983-01-01

    Applications of high power lasers are discussed which might fulfill the needs of NASA missions, and the technology characteristics of laser research programs are outlined. The status of the NASA programs or lasers, laser receivers, and laser propulsion is discussed, and recommendations are presented for a proposed expanded NASA program in these areas. Program elements that are critical are discussed in detail.

  14. A laser application to nuclear astrophysics

    SciTech Connect

    Barbui, M.; Hagel, K.; Schmidt, K.; Zheng, H.; Burch, R.; Barbarino, M.; Natowitz, J. B.; Bang, W.; Dyer, G.; Quevedo, H. J.; Gaul, E.; Bernstein, A. C.; Donovan, M.; Bonasera, A.; Kimura, S.; Mazzocco, M.; Consoli, F.; De Angelis, R.; Andreoli, P.; Ditmire, T.

    2014-05-09

    In the last decade, the availability in high-intensity laser beams capable of producing plasmas with ion energies large enough to induce nuclear reactions has opened new research paths in nuclear physics. We studied the reactions {sup 3}He(d,p){sup 4}He and d(d,n){sup 3}He at temperatures of few keV in a plasma, generated by the interaction of intense ultrafast laser pulses with molecular deuterium or deuterated-methane clusters mixed with {sup 3}He atoms. The yield of 14.7 MeV protons from the {sup 3}He(d,p){sup 4}He reaction was used to extract the astrophysical S factor. Results of the experiment performed at the Center for High Energy Density Science at The University of Texas at Austin will be presented.

  15. Laser Application in Prevention of Demineralization in Orthodontic Treatment

    PubMed Central

    Sadr Haghighi, Hooman; Skandarinejad, Mahsa; Abdollahi, Amir Ardalan

    2013-01-01

    One common negative side effect of orthodontic treatment with fixed appliances is the development of incipient caries lesions around brackets, particularly in patients with poor oral hygiene. Different methods have been used to prevent demineralization such as fluoride therapy and application of sealant to prevent caries. The recent effort to improve the resistance against the demineralization is by the application of different types of lasers. The purpose of this review article is discussing the effects of laser in prevention of demineralization in orthodontic patients. PMID:25606317

  16. Final optics protection in laser inertial fusion with cryogenic liquid droplets

    SciTech Connect

    Moir, R W

    2000-08-31

    A burst of x rays and vaporized debris from high yield targets can damage the final optics in laser inertial fusion energy (IFE) power plants and in laboratory experimental facilities such as the National Ignition Facility (NIF) or Laser MegaJoule (LMJ). Noble gases such as Xe or Kr have been proposed to protect final optics from target-produced x rays and debris. Some problems with the use of such ambient gas fills are the large amount of gas involved, heat transfer to a cryogenic target, potential resonant reradiation of x rays absorbed, and a nonuniform index of refraction due to turbulence interfering with the focusing of laser light. Also the fast igniter laser intensity may be too great for propagation through an ambient gas. We propose to provide the gas in the form of many small closely spaced liquid droplets injected in front of the optics. In the case of NIF, the droplets would be injected only when needed just before a high yield shot. The laser light that is absorbed will cause evaporation of the liquid and spreading of this gas. The liquid droplets intercept only {approx}5% of the laser light allowing {approx}95% to pass through to the target. The light absorbed in the NIF example (assumed to be 50% of the intercepted light, whose intensity is 3.6 x 10{sup 9} W/cm{sup 2}) would cause the xenon droplets to evaporate and spread uniformly such that the x rays from 10 eV to 2 keV are appreciably attenuated when they arrive 40 to 70 ns later at the optical surface. X rays above 3 keV and below 10 eV are not attenuated very much but their intensities are rapidly falling off in this range anyway. Typical droplet sizes are {approx}10 {micro}m radius with a spacing of {approx}0.4 mm. The gas would also protect vaporized target debris from condensing on the optics due to the 0.2 mg/cm{sup 2} of xenon (5 x 10{sup 17} cm{sup -2} or 8 Torr-cm for l-e-folding of 1 keV x-rays). These droplets might be produced with technology similar to ink jet technology and photo

  17. Ground-to-orbit laser propulsion: Advanced applications

    NASA Technical Reports Server (NTRS)

    Kare, Jordin T.

    1990-01-01

    Laser propulsion uses a large fixed laser to supply energy to heat an inert propellant in a rocket thruster. Such a system has two potential advantages: extreme simplicity of the thruster, and potentially high performance, particularly high exhaust velocity. By taking advantage of the simplicity of the thruster, it should be possible to launch small (10 to 1000 kg) payloads to orbit using roughly 1 MW of average laser power per kg of payload. The incremental cost of such launches would be of an order of $200/kg for the smallest systems, decreasing to essentially the cost of electricity to run the laser (a few times $10/kg) for larger systems. Although the individual payload size would be smaller, a laser launch system would be inherently high-volume, with the capacity to launch tens of thousands of payloads per year. Also, with high exhaust velocity, a laser launch system could launch payloads to high velocities - geosynchronous transfer, Earth escape, or beyond - at a relatively small premium over launches to LEO. The status of pulsed laser propulsion is briefly reviewed including proposals for advanced vehicles. Several applications appropriate to the early part of the next century and perhaps valuable well into the next millennium are discussed qualitatively: space habitat supply, deep space mission supply, nuclear waste disposal, and manned vehicle launching.

  18. Ground-to-orbit laser propulsion: Advanced applications

    SciTech Connect

    Kare, J.T.

    1990-01-01

    Laser propulsion uses a large fixed laser to supply energy to heat an inert propellant in a rocket thruster. Such a system has two potential advantages: extreme simplicity of the thruster, and potentially high performance -- particularly high exhaust velocity. By taking advantage of the simplicity of the thruster, it should be possible to launch small (10--1000 kg) payloads to orbit using roughly 1 MW of average laser power per kg of payload. The incremental cost of such launches would be of order $200/kg for the smallest systems, decreasing to essentially the cost of electricity to run the laser (a few times $10/kg) for large systems. Although the individual payload size would be small, a laser launch system would be inherently high-volume, with the capacity to launch tens of thousands of payloads per year. Also, with high exhaust velocity, a laser launch system could launch payloads to high velocities -- geosynchronous transfer, Earth escape, or beyond -- at a relatively small premium over launches to LEO. In this paper, we briefly review the status of pulsed laser propulsion, including proposals for advanced vehicles. We then discuss qualitatively several unique applications appropriate to the early part of the next century, and perhaps valuable well into the next millenium: space habitat supply, deep space mission supply, nuclear waste disposal, and manned vehicle launching.

  19. Clinical application of CO2 laser in periodontal treatment

    NASA Astrophysics Data System (ADS)

    Hayase, Yasuhiro

    1994-09-01

    CO2 lasers in particular are expected to have many dental applications because the CO2 laser beam exhibits strong tissue transpirative actions, such as instant coagulation, carbonization, and vaporization, and because its wavelength at 10.6 micrometers is fully absorbed by water so that the ability to make precise incisions with a high degree of safety is excellent, without damaging the deep tissues. However, clinical application of the CO2 laser has been slowed since a fiber which can conduct the laser beam to the oral cavity has only recently developed. This new fiber is an extremely flexible fiber with a minimum bending radius of 20 mm and utilizes pulse wave modes that have improved the handling characteristics in the mouth, and this has enabled us to apply the CO2 laser to a variety of periodontal conditions. The aim of this study was to evaluate the effectiveness of CO2 lasers for the early treatment of inflammation and pain relief of acute periodontitis, curettage of periodontal pockets, healing after excision of gingiva, and early improvement of gingivitis.

  20. Application of laser in conservation and restoration of historical building

    NASA Astrophysics Data System (ADS)

    Detalle, Vincent; Duch"ne, Stephanie; Verges Belmin, Veronique; Vallet, Jean Marc; Bodnar, Jean Luc

    2011-02-01

    Cultural Heritage has many analytical and treatment needs both in the field of conservation than in restoration. The laser therefore found a ready-made place in this area. We find first the different application of laser cleaning. The LRMH was the initiative of creating the first field prototype used in the field for cleaning stone in particular. A tour of the Cathedral of France to test this method had been achieved in the early 90s. Then, many have phenomenological and physical studies were conducted to understand the mechanisms involved during the cleaning action. In analytical technology, LIBS (Laser Induced Breakdown Spectroscopy) is used for in situ identification of pigments, salts, metals or other materials. This laser technique present a lot of advantages: portability, analysis of light elements, stratigraphic analysis capability ...The LRMH was the first laboratory depending from a ministry of culture to get the technology and to apply it systematically in situ (Saint-Savin sur Gartemps abbey...). In addition, more recently, a methodology for converting pigments by continuous laser was developed in the laboratory, thus extending the scope of the use of laser. We review these techniques and their application based on studies that occur in our laboratory.

  1. Application of laser in conservation and restoration of historical building

    NASA Astrophysics Data System (ADS)

    Detalle, Vincent; Duchêne, Stephanie; Verges Belmin, Veronique; Vallet, Jean Marc; Bodnar, Jean Luc

    2010-07-01

    Cultural Heritage has many analytical and treatment needs both in the field of conservation than in restoration. The laser therefore found a ready-made place in this area. We find first the different application of laser cleaning. The LRMH was the initiative of creating the first field prototype used in the field for cleaning stone in particular. A tour of the Cathedral of France to test this method had been achieved in the early 90s. Then, many have phenomenological and physical studies were conducted to understand the mechanisms involved during the cleaning action. In analytical technology, LIBS (Laser Induced Breakdown Spectroscopy) is used for in situ identification of pigments, salts, metals or other materials. This laser technique present a lot of advantages: portability, analysis of light elements, stratigraphic analysis capability ...The LRMH was the first laboratory depending from a ministry of culture to get the technology and to apply it systematically in situ (Saint-Savin sur Gartemps abbey...). In addition, more recently, a methodology for converting pigments by continuous laser was developed in the laboratory, thus extending the scope of the use of laser. We review these techniques and their application based on studies that occur in our laboratory.

  2. Status and future prospects of laser fusion and high power laser applications

    NASA Astrophysics Data System (ADS)

    Mima, Kunioki

    2010-08-01

    In Asia, there are many institutes for the R&D of high power laser science and applications. They are 5 major institutes in Japan, 4 major institutes in China, 2 institutes in Korea, and 3 institutes in India. The recent achievements and future prospects of those institutes will be over viewed. In the laser fusion research, the FIREX-I project in Japan has been progressing. The 10kJ short pulse LFEX laser has completed and started the experiments with a single beam. About 1kJ pulse energy will be injected into a cone target. The experimental results of the FIREX experiments will be presented. As the target design for the experiments, a new target, namely, a double cone target was proposed, in which the high energy electrons are well confined and the heating efficiency is significantly improved. Together with the fusion experiments, Osaka University has carried out laboratory astrophysics experiments on photo ionizing plasmas to observe a unique X-ray spectrum from non-LTE plasmas. In 2008, Osaka university has started a new Photon research center in relation with the new program: Consortium for Photon Science and Technology: C-PhoST, in which ultra intense laser plasmas research and related education will be carried out for 10 years. At APRI, JAEA, the fundamental science on the relativistic laser plasmas and the applications of laser particle acceleration has been developed. The application of laser ion acceleration has been investigated on the beam cancer therapy since 2007. In China, The high power glass laser: Shenguan-II and a peta watt beam have been operated to work on radiation hydro dynamics at SIOFM Shanghai. The laser material and optics are developed at SIOFM and LFRC. The IAPCM and the IOP continued the studies on radiation hydrodynamics and on relativistic laser plasmas interactions. At LFRC in China, the construction of Shenguan III glass laser of 200kJ in blue has progressed and will be completed in 2012. Together with the Korean program, I will

  3. Design Of High Power CO2 TEA Lasers And Applications

    NASA Astrophysics Data System (ADS)

    Von Bergmann, H. M.

    2008-09-01

    There are a number of key technologies involved in the successful design and construction of high power, Carbon Dioxide TEA lasers (Transverse Excitation Atmospheric). These include uniform field electrodes, excitation circuit design including high voltage switching, discharge preionisation and for high repetition, high power applications fast transverse gas flow and the management of acoustic waves. This paper provides a summary of the design aspects of high repetition rate, high average power CO2 TEA lasers. Experimental data measured on high power CO2 TEA laser systems delivering average outputs of several kW and kHz repetition rates will be reported showing the detrimental effect of acoustic waves on laser performance and the improvement that can be achieved through effective acoustic damping measures.

  4. Tunable solid state laser system for dermatology applications

    NASA Astrophysics Data System (ADS)

    Azar, Zion; Bank, Alexander; Donskoy, Dmitri M.; Nechitailo, Vladimir S.

    1994-12-01

    The Q-switched Nd:YAG laser is the most recent in a series of pulsed laser systems for plastic surgery. The 532 nm wavelength has been shown to be absorbed by a variety of chromophores. These include tattoo pigments, oxygenated hemoglobin and melanin-containing epidermal cells. A simple multi-line solid state laser module pumped by double-frequency Q- switched YAG laser is presented. This solid state multi-line module enables tuning of the wavelength in the yellow spectral range to 560 nm or to 580 nm for dermatology applications. Conversion efficiency in excess of 70% was achieved at 10 Hz pulse repetition frequency and output energy per pulse of approximately 200 mJ.

  5. Laser desorption mass spectrometry for biomolecule detection and its applications

    NASA Astrophysics Data System (ADS)

    Winston Chen, C. H.; Sammartano, L. J.; Isola, N. R.; Allman, S. L.

    2001-08-01

    During the past few years, we developed and used laser desorption mass spectrometry for biomolecule detections. Matrix-assisted laser desorption/ionization (MALDI) was successfully used to detect DNA fragments with the size larger than 3000 base pairs. It was also successfully used to sequence DNA with both enzymatic and chemical degradation methods to produce DNA ladders. We also developed MALDI with fragmentation for direct DNA sequencing for short DNA probes. Since laser desorption mass spectrometry for DNA detection has the advantages of fast speed and no need of labeling, it has a great potential for molecular diagnosis for disease and person identification by DNA fingerprinting. We applied laser desorption mass spectrometry to succeed in the diagnosis of cystic fibrosis and several other nerve degenerative diseases such as Huntington's disease. We also succeeded in demonstrating DNA typing for forensic applications.

  6. Atypical Applications for Gas-coupled Laser Acoustic Detection

    NASA Astrophysics Data System (ADS)

    Caron, J. N.; Kunapareddy, P.

    2014-06-01

    Gas-coupled laser acoustic detection (GCLAD) was primarily developed to sense laser-generated ultrasound in composite materials. In a typical setup, a laser beam is directed parallel to the material surface. Radiated ultrasound waves deflect or displace the probe beam resulting from changes in the air's index of refraction. A position-sensitive photodetector senses the beam movement, and produces a signal proportional to the ultrasound wave. In this paper, we discuss three applications of GCLAD that take advantage of the unique detection characteristics. Directivity patterns of ultrasound amplitude in water demonstrate the use of GCLAD as a directional hydrophone. We also demonstrate the sensing of waveforms from a gelatin. The gelatin mimics ultrasound propagation through skin tissues. Lastly, we show how GCLAD can be used as a line receiver for continuous laser generation of ultrasound. CLGU may enable ultrasound scanning at rates that are orders of magnitude faster than current methods.

  7. A qualitative and quantitative laser-based computer-aided flow visualization method. M.S. Thesis, 1992 Final Report

    NASA Technical Reports Server (NTRS)

    Canacci, Victor A.; Braun, M. Jack

    1994-01-01

    The experimental approach presented here offers a nonintrusive, qualitative and quantitative evaluation of full field flow patterns applicable in various geometries in a variety of fluids. This Full Flow Field Tracking (FFFT) Particle Image Velocimetry (PIV) technique, by means of particle tracers illuminated by a laser light sheet, offers an alternative to Laser Doppler Velocimetry (LDV), and intrusive systems such as Hot Wire/Film Anemometry. The method makes obtainable the flow patterns, and allows quantitative determination of the velocities, accelerations, and mass flows of an entire flow field. The method uses a computer based digitizing system attached through an imaging board to a low luminosity camera. A customized optical train allows the system to become a long distance microscope (LDM), allowing magnifications of areas of interest ranging up to 100 times. Presented in addition to the method itself, are studies in which the flow patterns and velocities were observed and evaluated in three distinct geometries, with three different working fluids. The first study involved pressure and flow analysis of a brush seal in oil. The next application involved studying the velocity and flow patterns in a cowl lip cooling passage of an air breathing aircraft engine using water as the working fluid. Finally, the method was extended to a study in air to examine the flows in a staggered pin arrangement located on one side of a branched duct.

  8. Laser Wakefield Acceleration: Structural and Dynamic Studies. Final Technical Report ER40954

    SciTech Connect

    Downer, Michael C.

    2014-04-30

    Particle accelerators enable scientists to study the fundamental structure of the universe, but have become the largest and most expensive of scientific instruments. In this project, we advanced the science and technology of laser-plasma accelerators, which are thousands of times smaller and less expensive than their conventional counterparts. In a laser-plasma accelerator, a powerful laser pulse exerts light pressure on an ionized gas, or plasma, thereby driving an electron density wave, which resembles the wake behind a boat. Electrostatic fields within this plasma wake reach tens of billions of volts per meter, fields far stronger than ordinary non-plasma matter (such as the matter that a conventional accelerator is made of) can withstand. Under the right conditions, stray electrons from the surrounding plasma become trapped within these “wake-fields”, surf them, and acquire energy much faster than is possible in a conventional accelerator. Laser-plasma accelerators thus might herald a new generation of compact, low-cost accelerators for future particle physics, x-ray and medical research. In this project, we made two major advances in the science of laser-plasma accelerators. The first of these was to accelerate electrons beyond 1 gigaelectronvolt (1 GeV) for the first time. In experimental results reported in Nature Communications in 2013, about 1 billion electrons were captured from a tenuous plasma (about 1/100 of atmosphere density) and accelerated to 2 GeV within about one inch, while maintaining less than 5% energy spread, and spreading out less than ½ milliradian (i.e. ½ millimeter per meter of travel). Low energy spread and high beam collimation are important for applications of accelerators as coherent x-ray sources or particle colliders. This advance was made possible by exploiting unique properties of the Texas Petawatt Laser, a powerful laser at the University of Texas at Austin that produces pulses of 150 femtoseconds (1 femtosecond is 10

  9. NEET-AMM Final Technical Report on Laser Direct Manufacturing (LDM) for Nuclear Power Components

    SciTech Connect

    Anderson, Scott; Baca, Georgina; O'Connor, Michael

    2015-12-31

    Final technical report summarizes the program progress and technical accomplishments of the Laser Direct Manufacturing (LDM) for Nuclear Power Components project. A series of experiments varying build process parameters (scan speed and laser power) were conducted at the outset to establish the optimal build conditions for each of the alloys. Fabrication was completed in collaboration with Quad City Manufacturing Laboratory (QCML). The density of all sample specimens was measured and compared to literature values. Optimal build process conditions giving fabricated part densities close to literature values were chosen for making mechanical test coupons. Test coupons whose principal axis is on the x-y plane (perpendicular to build direction) and on the z plane (parallel to build direction) were built and tested as part of the experimental build matrix to understand the impact of the anisotropic nature of the process.. Investigations are described 316L SS, Inconel 600, 718 and 800 and oxide dispersion strengthed 316L SS (Yttria) alloys.

  10. Laser-powered MHD generators for space application

    NASA Technical Reports Server (NTRS)

    Jalufka, N. W.

    1986-01-01

    Magnetohydrodynamic (MHD) energy conversion systems of the pulsed laser-supported detonation (LSD) wave, plasma MHD, and liquid-metal MHD (LMMHD) types are assessed for their potential as space-based laser-to-electrical power converters. These systems offer several advantages as energy converters relative to the present chemical, nuclear, and solar devices, including high conversion efficiency, simple design, high-temperature operation, high power density, and high reliability. Of these systems, the Brayton cycle liquid-metal MHD system appears to be the most attractive. The LMMHD technology base is well established for terrestrial applications, particularly with regard to the generator, mixer, and other system components. However, further research is required to extend this technology base to space applications and to establish the technology required to couple the laser energy into the system most efficiently. Continued research on each of the three system types is recommended.

  11. Abstracts of the 5th International Conference on Lasers and their Applications

    NASA Astrophysics Data System (ADS)

    Results were presented in the fields of laser physics and laser applications including the development of laser light sources, laser frequencies in the UV and VUV spectral regions using anti-Stokes Raman scattering, nonlinear optical effects for the formation of ultrashort optical pulses, laser spectroscopy, collisionless multiphoton excitation processes using molecular beams, selective generation of free radicals by laser, laser applications in medicine, plasma diagnostics analyzing X-ray spectra for studying laser fusion problems, coherence properties in phase-sampling interferometric techniques, and fundamental problems in quantum physics and nonlinear processes.

  12. The Application of Specific Point Energy Analysis to Laser Cutting with 1 μm Laser Radiation

    NASA Astrophysics Data System (ADS)

    Hashemzadeh, M.; Suder, W.; Williams, S.; Powell, J.; Kaplan, A. F. H.; Voisey, K. T.

    Specific point energy (SPE) is a concept that has been successfully used in laser welding where SPE and power density determine penetration depth. This type of analysis allows the welding characteristics of different laser systems to be directly compared. This paper investigates if the SPE concept can usefully be applied to laser cutting. In order to provide data for the analysis laser cutting of various thicknesses of mild steel with a 2 kW fibre laser was carried out over a wide range of parameter combinations. It was found that the SPE concept is applicable to laser cutting within the range of parameters investigated here.

  13. Mid - infrared solid state lasers for spectroscopic applications

    NASA Astrophysics Data System (ADS)

    Terekhov, Yuri

    This work is devoted to study of novel high power middle-infrared (Mid-IR) laser sources enabling development of portable platform for sensing of organic molecules with the use of recently discovered Quartz Enhanced Photo Acoustic Spectroscopy (QEPAS). The ability to detect small concentrations is beneficial to monitor atmosphere pollution as well for biomedical applications such as analysis of human breath to detect earlier stages of cancer or virus activities. A QEPAS technique using a quartz tuning fork (QTF) as a detector enables a strong enhancement of measured signal when pump laser is modulated with a frequency coinciding with a natural frequency of a QTF. It is known that the detectability of acousto-optics based sensors is proportional to the square root of the laser intensity used for detection of analyte. That is the reason why commercially available semiconductor Mid-IR lasers having small output power limit sensitivity of modern QEPAS based sensors. The lack of high power broadly tunable lasers operating with a modulation frequency of quartz forks (~ 32.768 kHz) is the major motivation of this study. Commercially available Mid-IR (2-3.3 microm), single frequency, continuous wave (CW) fiber pumped lasers based on transition metal doped chalcogenides (e.g. Cr:ZnSe) prove to be efficient laser sources for organic molecules detection. However, their direct modulation is limited to several kHz, and cannot be directly used in combination with QEPAS. Hence, one objective of this work is to study and develop fiber laser pumped Ho:YAG (Er:YAG)/Cr:ZnSe tandem laser system/s. Ho (Holmium) and/or Er (Erbium) ions having long radiation lifetime (~ 10 ms) can effectively accumulate population inversion under CW fiber laser excitation. Utilization of acousto-optic (AO) modulators in the cavity of Ho:YAG (Er:YAG) laser will enable effective Q-Switching with repetition rate easily reaching the resonance frequency of a QTF. It is expected that utilization of Ho:YAG (Er

  14. New developments in ophthalmic applications of ultrafast lasers

    NASA Astrophysics Data System (ADS)

    Spooner, Greg J. R.; Juhasz, Tibor; Ratkay-Traub, Imola; Djotyan, Gagik P.; Horvath, Christopher; Sacks, Zachary S.; Marre, Gabrielle; Miller, Doug L.; Williams, A. R.; Kurtz, Ron M.

    2000-05-01

    The eye is potentially an ideal target for high precision surgical procedures utilizing ultrafast lasers. We present progress on corneal applications now being tested in humans and proof of concept ex vivo demonstrations of new applications in the sclera and lens. Two corneal refractive procedures were tested in partially sighted human eyes: creation of corneal flaps prior to excimer ablation (Femto- LASIK) and creation of corneal channels and entry cuts for placement of intracorneal ring segments (Femto-ICRS). For both procedures, results were comparable to standard treatments, with the potential for improved safety, accuracy and reproducibility. For scleral applications, we evaluated the potential of femtosecond laser glaucoma surgery by demonstrating resections in ex vivo human sclera using dehydrating agents to induce tissue transparency. For lens applications, we demonstrate in an ex vivo model the use of photodisruptively-nucleated ultrasonic cavitation for local and non-invasive tissue interaction.

  15. Application of laser radar to autonomous spacecraft landing

    NASA Technical Reports Server (NTRS)

    Gleichman, Kurt; Tchoryk, Peter, Jr.; Sampson, Robert E.

    1991-01-01

    This paper discusses the scenario of an autonomous landing like that required for the Mars Rover Sample Return Mission. An application of laser radar for conducting autonomous hazard detection and avoidance is discussed. A trade-study is performed to identify operational and implementation constraints as well as the state of the art in component technology.

  16. Overview on new diode lasers for defense applications

    NASA Astrophysics Data System (ADS)

    Neukum, Joerg

    2012-11-01

    Diode lasers have a broad wavelength range, from the visible to beyond 2.2μm. This allows for various applications in the defense sector, ranging from classic pumping of DPSSL in range finders or target designators, up to pumping directed energy weapons in the 50+ kW range. Also direct diode applications for illumination above 1.55μm, or direct IR countermeasures are of interest. Here an overview is given on some new wavelengths and applications which are recently under discussion. In this overview the following aspects are reviewed: • High Power CW pumps at 808 / 880 / 940nm • Pumps for DPAL - Diode Pumped Alkali Lasers • High Power Diode Lasers in the range < 1.0 μm • Scalable Mini-Bar concept for high brightness fiber coupled modules • The Light Weight Fiber Coupled module based on the Mini-Bar concept Overall, High Power Diode Lasers offer many ways to be used in new applications in the defense market.

  17. High efficiency solar cells for laser power beaming applications

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, G. A.

    1995-01-01

    Understanding solar cell response to pulsed laser outputs is important for the evaluation of power beaming applications. The time response of high efficiency GaAs and silicon solar cells to a 25 nS monochromatic pulse input is described. The PC-1D computer code is used to analyze the cell current during and after the pulse for various conditions.

  18. Multiple-Zone Diffractive Optic Element for Laser Ranging Applications

    NASA Technical Reports Server (NTRS)

    Ramos-Izquierdo, Luis A.

    2011-01-01

    A diffractive optic element (DOE) can be used as a beam splitter to generate multiple laser beams from a single input laser beam. This technology has been recently used in LRO s Lunar Orbiter Laser Altimeter (LOLA) instrument to generate five laser beams that measure the lunar topography from a 50-km nominal mapping orbit (see figure). An extension of this approach is to use a multiple-zone DOE to allow a laser altimeter instrument to operate over a wider range of distances. In particular, a multiple-zone DOE could be used for applications that require both mapping and landing on a planetary body. In this case, the laser altimeter operating range would need to extend from several hundred kilometers down to a few meters. The innovator was recently involved in an investigation how to modify the LOLA instrument for the OSIRIS asteroid mapping and sample return mission. One approach is to replace the DOE in the LOLA laser beam expander assembly with a multiple-zone DOE that would allow for the simultaneous illumination of the asteroid with mapping and landing laser beams. The proposed OSIRIS multiple-zone DOE would generate the same LOLA five-beam output pattern for high-altitude topographic mapping, but would simultaneously generate a wide divergence angle beam using a small portion of the total laser energy for the approach and landing portion of the mission. Only a few percent of the total laser energy is required for approach and landing operations as the return signal increases as the inverse square of the ranging height. A wide divergence beam could be implemented by making the center of the DOE a diffractive or refractive negative lens. The beam energy and beam divergence characteristics of a multiple-zone DOE could be easily tailored to meet the requirements of other missions that require laser ranging data. Current single-zone DOE lithographic manufacturing techniques could also be used to fabricate a multiple-zone DOE by masking the different DOE zones during

  19. Application and the key technology on high power fiber-optic laser in laser weapon

    NASA Astrophysics Data System (ADS)

    Qu, Zhou; Li, Qiushi; Meng, Haihong; Sui, Xin; Zhang, Hongtao; Zhai, Xuhua

    2014-12-01

    The soft-killing laser weapon plays an important role in photoelectric defense technology. It can be used for photoelectric detection, search, blinding of photoelectric sensor and other devices on fire control and guidance devices, therefore it draws more and more attentions by many scholars. High power fiber-optic laser has many virtues such as small volume, simple structure, nimble handling, high efficiency, qualified light beam, easy thermal management, leading to blinding. Consequently, it may be used as the key device of soft-killing laser weapon. The present study introduced the development of high power fiber-optic laser and its main features. Meanwhile the key technology of large mode area (LMA) optical fiber design, the beam combination technology, double-clad fiber technology and pumping optical coupling technology was stated. The present study is aimed to design high doping LMA fiber, ensure single mode output by increasing core diameter and decrease NA. By means of reducing the spontaneous emission particle absorbed by fiber core and Increasing the power density in the optical fiber, the threshold power of nonlinear effect can increase, and the power of single fiber will be improved. Meantime, high power will be obtained by the beam combination technology. Application prospect of high power fiber laser in photoelectric defense technology was also set forth. Lastly, the present study explored the advantages of high power fiber laser in photoelectric defense technology.

  20. Review of selective laser melting: Materials and applications

    NASA Astrophysics Data System (ADS)

    Yap, C. Y.; Chua, C. K.; Dong, Z. L.; Liu, Z. H.; Zhang, D. Q.; Loh, L. E.; Sing, S. L.

    2015-12-01

    Selective Laser Melting (SLM) is a particular rapid prototyping, 3D printing, or Additive Manufacturing (AM) technique designed to use high power-density laser to melt and fuse metallic powders. A component is built by selectively melting and fusing powders within and between layers. The SLM technique is also commonly known as direct selective laser sintering, LaserCusing, and direct metal laser sintering, and this technique has been proven to produce near net-shape parts up to 99.9% relative density. This enables the process to build near full density functional parts and has viable economic benefits. Recent developments of fibre optics and high-power laser have also enabled SLM to process different metallic materials, such as copper, aluminium, and tungsten. Similarly, this has also opened up research opportunities in SLM of ceramic and composite materials. The review presents the SLM process and some of the common physical phenomena associated with this AM technology. It then focuses on the following areas: (a) applications of SLM materials and (b) mechanical properties of SLM parts achieved in research publications. The review is not meant to put a ceiling on the capabilities of the SLM process but to enable readers to have an overview on the material properties achieved by the SLM process so far. Trends in research of SLM are also elaborated in the last section.

  1. Review of selective laser melting: Materials and applications

    SciTech Connect

    Yap, C. Y.; Chua, C. K. Liu, Z. H. Zhang, D. Q. Loh, L. E. Sing, S. L.; Dong, Z. L.

    2015-12-15

    Selective Laser Melting (SLM) is a particular rapid prototyping, 3D printing, or Additive Manufacturing (AM) technique designed to use high power-density laser to melt and fuse metallic powders. A component is built by selectively melting and fusing powders within and between layers. The SLM technique is also commonly known as direct selective laser sintering, LaserCusing, and direct metal laser sintering, and this technique has been proven to produce near net-shape parts up to 99.9% relative density. This enables the process to build near full density functional parts and has viable economic benefits. Recent developments of fibre optics and high-power laser have also enabled SLM to process different metallic materials, such as copper, aluminium, and tungsten. Similarly, this has also opened up research opportunities in SLM of ceramic and composite materials. The review presents the SLM process and some of the common physical phenomena associated with this AM technology. It then focuses on the following areas: (a) applications of SLM materials and (b) mechanical properties of SLM parts achieved in research publications. The review is not meant to put a ceiling on the capabilities of the SLM process but to enable readers to have an overview on the material properties achieved by the SLM process so far. Trends in research of SLM are also elaborated in the last section.

  2. Applications of laser direct-write for embedding microelectronics

    NASA Astrophysics Data System (ADS)

    Piqué, Alberto; Charipar, Nicholas A.; Kim, Heungsoo; Auyeung, Ray C. Y.; Mathews, Scott A.

    2007-03-01

    The use of direct-write techniques might revolutionize the way microelectronic devices such as interconnects, passives, IC's, antennas, sensors and power sources are designed and fabricated. The Naval Research Laboratory has developed a laser-based microfabrication process for direct-writing the materials and components required for the assembly and interconnection of the above devices. This laser direct-write (LDW) technique is capable of operating in subtractive, additive, and transfer mode. In subtractive mode, the system operates as a laser micromachining workstation capable of achieving precise depth and surface roughness control. In additive mode, the system utilizes a laser-forward transfer process for the deposition of metals, oxides, polymers and composites under ambient conditions onto virtually any type of surface, thus functioning as a laser printer for patterns of electronic materials. Furthermore, in transfer mode, the system is capable of transferring individual devices, such as semiconductor bare die or surface mount devices, inside a trench or recess in a substrate, thus performing the same function of the pick-and-place machines used in circuit board manufacture. The use of this technique is ideally suited for the rapid prototyping of embedded microelectronic components and systems while allowing the overall circuit design and layout to be easily modified or adapted to any specific application or form factor. This paper describes the laser direct-write process as applied to the forward transfer of microelectronic devices.

  3. Laser ablative cutting of ceramics for electronics applications

    SciTech Connect

    Warner, B. E., LLNL

    1996-03-01

    Pulsed, high-beam quality lasers offer unique materials processing characteristics. In processing metals, copper vapor and pulsed Nd:YAG lasers have produced micron-scale cuts and holes with submicron heat-affected zones. Since the cost of laser photons is high and average material removal rates can be slow with ablation, high value-added applications are necessary to justify processing costs. Ceramics present a special challenge for manufacturing because of their high hardness, relatively low thermal conductivity, and brittle nature. Surface damage typically limits the strength of a ceramic part to a small fraction of its bulk strength. This work investigates the use of copper vapor and pulsed diode-pumped Nd:YAG lasers to cut precision features in ceramic substrates. Variations in laser wavelength and power, processing speed, ceramic type, and assist gas were investigated with the goal of producing <100-{mu}m wide by 600-{mu}m deep cuts through silicon-carbide and alumina/titanium-carbide substrates for potential use in electronics. Silicon-carbide bars 250-{mu}m wide by 600-{mu}m high by 2.5-cm long were laser cut from substrates without fracture.

  4. Low Energy Laser Biostimulation: New Prospects For Medical Applications

    NASA Astrophysics Data System (ADS)

    Castel, John C.; Abergel, R. Patrick; Willner, Robert E.; Baumann, James G.

    1987-03-01

    The therapeutic benefits of light-energy is not a new concept to the modern world. Documented applications from ancient times tell of the therapeutic effects of ordinary sun-light to treat such common ailments as painful body joints, wounds, compound fractures and tetanus. The discovery of laser light in the 1960's, opened up new prospects for the medical use of light. Laser light differs from other forms of electromagnetic spectrum in that a single wavelength rather than a spectrum of wavelengths is emitted. Since the early 1970's, low-energy laser radiation has been reported to enhance wound healing rates, reduce edema, and relieve musculoskeletal pain. There is no detectable thermal effect of this laser on the tissue being treated. The effects are considered to occur as a result of photochemical, non thermal effects of the laser beam. Photons are absorbed by the tissue being treated and, in turn, produce positive therapeutic effects such as reduction of pain and edema. Pre-clinical and clinical evaluations are, presently, underway to document the safety and efficacy of low energy laser therapy, which represents a significant advance in the non-invasive treatment of pain.

  5. Aspects of laser optics qualification for space applications

    NASA Astrophysics Data System (ADS)

    Riede, Wolfgang; Allenspacher, Paul; Schröder, Helmut; Mahnke, Peter; Paunescu, Gabriela; Wernham, Denny

    2009-10-01

    As a consequence of the ongoing interest for deployment of laser systems into space, suitable optical components have to be developed and must be extensively space qualified to ensure reliable, continuous, and autonomous operation. The exposure to space environment can adversely affect the longevity of optics, mainly coatings, and lead to system degradation. An increased operational risk is due to the air-vacuum effect, which can strongly reduce the laser damage resistance of optical coatings. For this purpose, a vacuum laser damage test bench has been developed and is operated at DLR. In extensive test campaigns, all damage-prone optics of the ALADIN laser system (being the laser source of the upcoming ESA ADM Aeolus mission) were tested under operative conditions at the fundamental and at the harmonic wavelengths of Nd:YAG. Further operational risks are due directly to operation under high vacuum. In the past, several space-based laser missions have suffered from anomalous performance loss or even failure after short operation times. This degradation is due to selective contamination of laser-exposed optical surfaces fed by outgassing constituents. These volatile components are omnipresent in vacuum vessels. Various organic and inorganic species were tested at our facilities for their criticality on deposit built-up. Finally, active optical components like Q-switch crystals or frequency converter crystals can also suffer from bulk absorption induced by high-energy radiation (gray tracking) and dehydration. To analyze these effects, an ultrahigh vacuum phase matching unit was set up to test various combinations of SHG and THG frequency converters.

  6. Laser heating of dielectric particles for medical and biological applications

    PubMed Central

    Tribelsky, Michael I.

    2016-01-01

    We consider the general problem of laser pulse heating of a spherical dielectric particle embedded in a liquid. The discussed range of the problem parameters is typical for medical and biological applications. We focus on the case, when the heat diffusivity in the particle is of the same order of magnitude as that in the fluid. We perform quantitative analysis of the heat transfer equation based on interplay of four characteristic scales of the problem, namely the particle radius, the characteristic depth of light absorption in the material of the particle and the two heat diffusion lengths: in the particle and in the embedding liquid. A new quantitative characteristic of the laser action, that is the cooling time, describing the temporal scale of the cooling down of the particle after the laser pulse is over, is introduced and discussed. Simple analytical formulas for the temperature rise in the center of the particle and at its surface as well as for the cooling time are obtained. We show that at the appropriate choice of the problem parameters the cooling time may be by many orders of magnitude larger the laser pulse duration. It makes possible to minimize the undesirable damage of healthy tissues owing to the finite size of the laser beam and scattering of the laser radiation, simultaneously keeping the total hyperthermia period large enough to kill the pathogenic cells. An example of application of the developed approach to optimization of the therapeutic effect at the laser heating of particles for cancer therapy is presented. PMID:27446706

  7. Laser heating of dielectric particles for medical and biological applications.

    PubMed

    Tribelsky, Michael I; Fukumoto, Yasuhide

    2016-07-01

    We consider the general problem of laser pulse heating of a spherical dielectric particle embedded in a liquid. The discussed range of the problem parameters is typical for medical and biological applications. We focus on the case, when the heat diffusivity in the particle is of the same order of magnitude as that in the fluid. We perform quantitative analysis of the heat transfer equation based on interplay of four characteristic scales of the problem, namely the particle radius, the characteristic depth of light absorption in the material of the particle and the two heat diffusion lengths: in the particle and in the embedding liquid. A new quantitative characteristic of the laser action, that is the cooling time, describing the temporal scale of the cooling down of the particle after the laser pulse is over, is introduced and discussed. Simple analytical formulas for the temperature rise in the center of the particle and at its surface as well as for the cooling time are obtained. We show that at the appropriate choice of the problem parameters the cooling time may be by many orders of magnitude larger the laser pulse duration. It makes possible to minimize the undesirable damage of healthy tissues owing to the finite size of the laser beam and scattering of the laser radiation, simultaneously keeping the total hyperthermia period large enough to kill the pathogenic cells. An example of application of the developed approach to optimization of the therapeutic effect at the laser heating of particles for cancer therapy is presented. PMID:27446706

  8. Ultra-narrow gap laser welding of BeAl alloys. Final report

    SciTech Connect

    Milewski, J.O.; Sklar, E.

    1998-11-01

    The original scope of the project was to develop a method to enhance the laser welding of BeAl alloys by the use of weld joint designs based on the principals of non-imaging optics. The projected three year program focused on the development of geometric optical models which predict the trapping of laser energy within the weld joint and experimental validation of these models. The first year was fully funded, meeting all expectations and deliverables for the demonstration of the method for aluminum only. The second year funding levels did not allow any work to be done at Los Alamos. OptiCAD continued with model development with a change in scope to model the laser welding requirements of ongoing weapons related programs which could provide data for model validation. The project ended at the end of FY97 without funding a third year and never reaching the goal of welding beryllium, as a result. Despite the poor funding situation, original quality process research was accomplished and reported as described in the three technical reports of Appendix A. Solid technical contribution, directly applicable to weapons programs is evidenced by the inclusion of an optically designed laser weld joint being specified on a LANL drawing of an aluminum subassembly.

  9. Satellite laser ranging and its applications

    NASA Technical Reports Server (NTRS)

    Tapley, B. D.; Schutz, B. E.; Eanes, R. J.

    1985-01-01

    Satellite laser ranging (SLR) provides an important capability for precise orbit determination and for geophysical parameter estimation to support a number of contemporary geodynamic and oceanographic investigations. The precision of the SLR measurement has improved from the early meter-level systems to the current capabilities of a few centimeters for the best systems. The accuracy of the orbits and geophysical parameter recovery have shown an associated improvement. Polar motion with accuracies of 2 mas, station coordinates better than 10 cm, and interstation baseline rates indicative of tectonic motion are determined routinely with the current set of global SLR data. This discussion reviews the SLR measurement, analysis approach, and some of the recent results derived from the current SLR data set.

  10. Solid state laser applications in photovoltaics manufacturing

    NASA Astrophysics Data System (ADS)

    Dunsky, Corey; Colville, Finlay

    2008-02-01

    Photovoltaic energy conversion devices are on a rapidly accelerating growth path driven by increasing government and societal pressure to use renewable energy as part of an overall strategy to address global warming attributed to greenhouse gas emissions. Initially supported in several countries by generous tax subsidies, solar cell manufacturers are relentlessly pushing the performance/cost ratio of these devices in a quest to reach true cost parity with grid electricity. Clearly this eventual goal will result in further acceleration in the overall market growth. Silicon wafer based solar cells are currently the mainstay of solar end-user installations with a cost up to three times grid electricity. But next-generation technology in the form of thin-film devices promises streamlined, high-volume manufacturing and greatly reduced silicon consumption, resulting in dramatically lower per unit fabrication costs. Notwithstanding the modest conversion efficiency of thin-film devices compared to wafered silicon products (around 6-10% versus 15-20%), this cost reduction is driving existing and start-up solar manufacturers to switch to thin-film production. A key aspect of these devices is patterning large panels to create a monolithic array of series-interconnected cells to form a low current, high voltage module. This patterning is accomplished in three critical scribing processes called P1, P2, and P3. Lasers are the technology of choice for these processes, delivering the desired combination of high throughput and narrow, clean scribes. This paper examines these processes and discusses the optimization of industrial lasers to meet their specific needs.

  11. Laser sampling system for an inductively-coupled atomic emission spectrometer. Final report

    SciTech Connect

    1998-02-15

    A laser sampling system was attached to a Perkin Elmer Optima 3000 inductively-coupled plasma, atomic emission spectrometer that was already installed and operating in the Chemistry and Geochemistry Department at the Colorado School of Mines. The use of the spectrometer has been highly successful. Graduate students and faculty from at least four different departments across the CSM campus have used the instrument. The final report to NSF is appended to this final report. Appendices are included which summarize several projects utilizing this instrument: acquisition of an inductively-coupled plasma atomic emission spectrometer for the geochemistry program; hydrogen damage susceptibility assessment for high strength steel weldments through advanced hydrogen content analysis, 1996 and 1997 annual reports; and methods for determination of hydrogen distribution in high strength steel welds.

  12. Laser applications and system considerations in ocular imaging

    PubMed Central

    Elsner, Ann E.; Muller, Matthew S.

    2009-01-01

    We review laser applications for primarily in vivo ocular imaging techniques, describing their constraints based on biological tissue properties, safety, and the performance of the imaging system. We discuss the need for cost effective sources with practical wavelength tuning capabilities for spectral studies. Techniques to probe the pathological changes of layers beneath the highly scattering retina and diagnose the onset of various eye diseases are described. The recent development of several optical coherence tomography based systems for functional ocular imaging is reviewed, as well as linear and nonlinear ocular imaging techniques performed with ultrafast lasers, emphasizing recent source developments and methods to enhance imaging contrast. PMID:21052482

  13. Application of in vivo laser scanning microscope in dermatology

    NASA Astrophysics Data System (ADS)

    Lademann, Juergen; Richter, H.; Otberg, N.; Lawrenz, F.; Blume-Peytavi, U.; Sterry, W.

    2003-10-01

    The state of the art of in-vivo and in-vitro penetration measurements of topically applied substances is described. Only optical techniques represent online measuring methods based on the absorption or scattering properties of the topically applied substances. Laser scanning microscopy (LSM) has become a promising method for investigations in dermatology and skin physiology, after it was possible to analyze the skin surface on any body side in-vivo. In the present paper the application of a dermatological laser scanning microscope for penetration and distribution measurements of topically applied substances is described. The intercellular and follicular penetration pathways were studied.

  14. In vitro and in vivo studies on laser-activated gold nanorods for applications in photothermal therapies

    NASA Astrophysics Data System (ADS)

    Pini, Roberto; Ratto, Fulvio; Matteini, Paolo; Centi, Sonia; Rossi, Francesca

    2010-04-01

    We review our experimental studies on near infrared laser-activated gold nanoparticles in the direct welding of connective tissues. In particular, we discuss the use of gold nanorods excited by diode laser radiation at 810 nm to mediate functional photothermal effects and weld eye's lens capsules and arteries. The preparation of biopolymeric matrices including gold nanorods is described as well, together with preliminary tests for their application in the closure of wounds in vessels and tendons. Finally we mention future perspectives on the use of these nanoparticles for applications in the therapy of cancer.

  15. Ex vivo laser lipolysis assisted with radially diffusing optical applicator

    NASA Astrophysics Data System (ADS)

    Hwang, Jieun; Hau, Nguyen Trung; Park, Sung Yeon; Rhee, Yun-Hee; Ahn, Jin-Chul; Kang, Hyun Wook

    2016-05-01

    Laser-assisted lipolysis has been implemented to reduce body fat in light of thermal interactions with adipose tissue. However, using a flat fiber with high irradiance often needs rapid cannula movements and even undesirable thermal injury due to direct tissue contact. The aim of the current study was to explore the feasibility of a radially diffusing optical applicator to liquefy the adipose tissue for effective laser lipolysis. The proposed diffuser was evaluated with a flat fiber in terms of temperature elevation and tissue liquefaction after laser lipolysis with a 980-nm wavelength. Given the same power (20 W), the diffusing applicator generated a 30% slower temperature increase with a 25% lower maximum temperature (84±3.2°C in 1 min p<0.001) in the tissue, compared with the flat fiber. Under the equivalent temperature development, the diffuser induced up to fivefold larger area of the adipose liquefaction due to radial light emission than the flat fiber. Ex vivo tissue tests for 5-min irradiation demonstrated that the diffuser (1.24±0.15 g) liquefied 66% more adipose tissue than the flat fiber (0.75±0.05 g). The proposed diffusing applicator can be a feasible therapeutic device for laser lipolysis due to low temperature development and wide coverage of thermal treatment.

  16. Ex vivo laser lipolysis assisted with radially diffusing optical applicator

    NASA Astrophysics Data System (ADS)

    Hwang, Jieun; Hau, Nguyen Trung; Park, Sung Yeon; Rhee, Yun-Hee; Ahn, Jin-Chul; Kang, Hyun Wook

    2016-05-01

    Laser-assisted lipolysis has been implemented to reduce body fat in light of thermal interactions with adipose tissue. However, using a flat fiber with high irradiance often needs rapid cannula movements and even undesirable thermal injury due to direct tissue contact. The aim of the current study was to explore the feasibility of a radially diffusing optical applicator to liquefy the adipose tissue for effective laser lipolysis. The proposed diffuser was evaluated with a flat fiber in terms of temperature elevation and tissue liquefaction after laser lipolysis with a 980-nm wavelength. Given the same power (20 W), the diffusing applicator generated a 30% slower temperature increase with a 25% lower maximum temperature (84±3.2°C in 1 min p<0.001) in the tissue, compared with the flat fiber. Under the equivalent temperature development, the diffuser induced up to fivefold larger area of the adipose liquefaction due to radial light emission than the flat fiber. Ex vivo tissue tests for 5-min irradiation demonstrated that the diffuser (1.24±0.15 g) liquefied 66% more adipose tissue than the flat fiber (0.75±0.05 g). The proposed diffusing applicator can be a feasible therapeutic device for laser lipolysis due to low temperature development and wide coverage of thermal treatment.

  17. Blue laser diode (LD) and light emitting diode (LED) applications

    NASA Astrophysics Data System (ADS)

    Bergh, Arpad A.

    2004-09-01

    The family of blue LEDs, edge emitting and surface emitting lasers, enable a number of applications. Blue lasers are used in digital applications such as optical storage in high density DVDs. The resolution of the spot size and hence the storage density is diffraction limited and is inversely proportional to the square of the wavelength of the laser. Other applications include printing, optical scanners, and high-resolution photo-lithography.As light emitters, blue LEDs are used for signaling and in direct view large area emissive displays. They are also making inroads into signage and LCD back-lighting, mobile platforms, and decorative accent lighting in curtains, furniture, etc.Blue LEDs produce white light either with phosphor wavelength converters or in combination with red and green LEDs. The full potential of LED light sources will require three devices to enable complete control over color and intensity.Sensing and medical/bio applications have a major impact on home security, on monitoring the environment, and on health care. New emerging diagnostic and therapeutic applications will improve the quality and reduce the cost of health care.

  18. Design definition of the Laser Atmospheric Wind Sounder (LAWS), phase 2. Volume 2: Final report

    NASA Technical Reports Server (NTRS)

    Wilson, D. J.

    1992-01-01

    Lockheed personnel, along with team member subcontractors and consultants, have performed a preliminary design for the LAWS Instrument. Breadboarding and testing of a LAWS class laser have also been performed. These efforts have demonstrated that LAWS is a feasible Instrument and can be developed with existing state-of-the-art technology. Only a commitment to fund the instrument development and deployment is required to place LAWS in orbit and obtain the anticipated science and operational forecasting benefits. The LAWS Science Team was selected in 1988-89 as were the competing LAWS phase 1/2 contractor teams. The LAWS Science Team developed requirements for the LAWS Instrument, and the NASA/LAWS project office defined launch vehicle and platform design constraints. From these requirements and constraints, the lockheed team developed LAWS Instrument concepts and configurations. A system designed to meet these requirements and constraints is outlined. The LAWS primary subsystem and interfaces - laser, optical, and receiver/processor - required to assemble a lidar are identified. Also identified are the support subsystems required for the lidar to function from space: structures and mechanical, thermal, electrical, and command and data management. The Lockheed team has developed a preliminary design of a LAWS Instrument System consisting of these subsystems and interfaces which will meet the requirements and objectives of the Science Team. This final report provides a summary of the systems engineering analyses and trades of the LAWS. Summaries of the configuration, preliminary designs of the subsystems, testing recommendations, and performance analysis are presented. Environmental considerations associated with deployment of LAWS are discussed. Finally, the successful LAWS laser breadboard effort is discussed along with the requirements and test results.

  19. Evaluation of Laser Stabilization and Imaging Systems for LCLS-II - Final Paper

    SciTech Connect

    Barry, Matthew

    2015-08-20

    By combining the top performing commercial laser beam stabilization system with the most ideal optical imaging configuration, the beamline for the Linear Accelerator Coherent Light Source II (LCLS-II) will deliver the highest quality and most stable beam to the cathode. To determine the optimal combination, LCLS-II beamline conditions were replicated and the systems tested with a He-Ne laser. The Guidestar-II and MRC active laser beam stabilization systems were evaluated for their ideal positioning and stability. Both a two and four lens optical imaging configuration was then evaluated for beam imaging quality, magnification properties, and natural stability. In their best performances when tested over fifteen hours, Guidestar-II kept the beam stable over approximately 70-110um while the MRC system kept it stable over approximately 90-100um. During short periods of time, Guidestar-II kept the beam stable between 10-20um, but was more susceptible to drift over time, while the MRC system maintained the beam between 30-50um with less overall drift. The best optical imaging configuration proved to be a four lens system that images to the iris located in the cathode room and from there, imaged to the cathode. The magnification from the iris to the cathode was 2:1, within an acceptable tolerance to the expected 2.1:1 magnification. The two lens configuration was slightly more stable in small periods of time (less than 10 minutes) without the assistance of a stability system, approximately 55um compared to approximately 70um, but the four lens configurations beam image had a significantly flatter intensity distribution compared to the two lens configuration which had a Gaussian distribution. A final test still needs to be run with both stability systems running at the same time through the four lens system. With this data, the optimal laser beam stabilization system can be determined for the beamline of LCLS-II.

  20. Monocrystalline CVD-diamond optics for high-power laser applications

    NASA Astrophysics Data System (ADS)

    Holly, C.; Traub, M.; Hoffmann, D.; Widmann, C.; Brink, D.; Nebel, C.; Gotthardt, T.; Sözbir, M. C.; Wenzel, C.

    2016-03-01

    The potential of diamond as an optical material for high-power laser applications in the wavelength regime from the visible spectrum (VIS) to the near infrared (NIR) is investigated. Single-crystal diamonds with lateral dimensions up to 7×7mm2 are grown with microwave plasma assisted chemical vapor deposition (MPACVD) in parallel with up to 60 substrates and are further processed to spherical optics for beam guidance and shaping. The synthetic diamonds offer superior thermal, mechanical and optical properties, including low birefringence, scattering and absorption, also around 1 μm wavelength. We present dielectric (AR and HR) coated single-crystal diamond optics which are tested under high laser power in the multi-kW regime. The thermally induced focal shift of the diamond substrates is compared to the focal shift of a standard collimating and focusing unit for laser cutting made of fused silica optics. Due to the high thermal conductivity and low absorption of the diamond substrates compared to the fused silica optics no additional focal shift caused by a thermally induced refractive index change in the diamond is observed in our experiments. We present experimental results regarding the performance of the diamond substrates with and without dielectric coatings under high power and the influences of growth induced birefringence on the optical quality. Finally, we discuss the potential of the presented diamond lenses for high-power applications in the field of laser materials processing.

  1. Scaling of solid state lasers for satellite power beaming applications

    SciTech Connect

    Friedman, H.W.; Albrecht, G.F.; Beach, R.J.

    1994-01-01

    The power requirements for a satellite power beaming laser system depend upon the diameter of the beam director, the performance of the adaptive optics system, and the mission requirements. For an 8 meter beam director and overall Strehl ratio of 50%, a 30 kW laser at 850 nm can deliver an equivalent solar flux to a satellite at geostationary orbit. Advances in Diode Pumped Solid State Lasers (DPSSL) have brought these small, efficient and reliable devices to high average power and they should be considered for satellite power beaming applications. Two solid state systems are described: a diode pumped Alexandrite and diode pumped Thulium doped YAG. Both can deliver high average power at 850 nm in a single aperture.

  2. Scaling of solid state lasers for satellite power beaming applications

    SciTech Connect

    Friedman, H.; Albrecht, G.; Beach, R.

    1994-12-31

    The power requirements for a satellite power beaming laser system depend upon the diameter of the beam director, the performance of the adaptive optics system, and the mission requirements. For an 8 meter beam director and overall Strehl ratio of 50%, a 30 kW laser at 850 nm can deliver an equivalent solar flux to a satellite at geostationary orbit. Advances in Diode Pumped Solid State Lasers (DPSSL) have brought these small, efficient and reliable devices to high average power and they should be considered for satellite power beaming applications. Two solid state systems are described: a diode pumped Alexandrite and diode pumped Thulium doped YAG. Both can deliver high average power at 850 nm in a single aperture.

  3. Novel applications of femtosecond laser in missile countermeasures

    NASA Astrophysics Data System (ADS)

    Marquis, E.; Pocholle, J. P.

    2005-11-01

    Femtosecond lasers have been widely used in laboratories for years and are now suitable for industrial applications and new military ones. Due to their very short pulse duration, they have the capability to generate intense electric fields and plasmas in targeted materials. We present here a novel scheme of missile counter-measure that is using such an intense laser source to disrupt the operation of IR guidance systems. Classical lasers for missile defense are based on thermal effects on the target whereas photons are used as the kill vehicle [1,2]. In femtosecond countermeasure, the average power is quite low, but the very intense field creates ionization effects than can damage sensitive optics and also plasma that can be used as active decoys against IR homing electronics. As the recent systems are compact and portable, an airport protection scheme is proposed to eliminate manpads threats in the vicinity of a civilian airport.

  4. Laser-induced stress transients: applications for molecular delivery

    NASA Astrophysics Data System (ADS)

    Flotte, Thomas J.; Lee, Shun; Zhang, Hong; McAuliffe, Daniel J.; Douki, Tina; Doukas, Apostolos G.

    1995-05-01

    Lasers can be used to enhance the delivery of a number of molecules. Other investigators have demonstrated local release of molecules from liposomes following laser irradiation, microbeam disruption of the cell membrane to increase cell transport, microbeam ablation of the zona pellucida surrounding the ovum to increase the chances of fertilization, and increased transcutaneous transport following ablation of the stratum corneum. Our experiments have shown that laser-induced stress transients can be utilized as a vector for intracellular delivery of molecules that may or may not normally cross the cell membrane. These two conditions have been tested with Photofrin and DNA. This technology may have applications in cell and molecular biology, cancer therapy, gene therapy, and others.

  5. Medical and biological applications for ultrafast laser pulses

    NASA Astrophysics Data System (ADS)

    Lubatschowski, Holger; Heisterkamp, Alexander; Will, Fabian; Singh, Ajoy I.; Serbin, Jesper; Ostendorf, Andreas; Kermani, Omid; Heermann, R.; Welling, Herbert; Ertmer, Wolfgang

    2003-02-01

    Due to the low energy threshold of photodisruption with fs laser pulses, thermal and mechanical side effects are limited to the sub μm range. The neglection of side effects enables the use of ultrashort laser pulses in a broad field of medical applications. Moreover, the interaction process based on nonlinear absorption offers the opportunity to process transparent tissue three dimensionally inside the bulk. We demonstrate the feasibility of surgical procedures in different fields of medical interest: In ophthalmology intrastromal cutting and preparing of corneal flaps for refractive surgery in living animals is presented. Besides, the very low mechanical side effects enables the use of fs-laser in otoralyngology to treat ocecular bones. Moreover, the precise cutting quality can be used in fields of cardiovascular surgery for the treatment of arteriosclerosis as well as in dentistry to remove caries from dental hard tissue.

  6. Laser flare-cell photometry: methodology and clinical applications.

    PubMed

    Ladas, John G; Wheeler, Noel C; Morhun, Patrick J; Rimmer, Steven O; Holland, Gary N

    2005-01-01

    Diagnosis and management of intraocular inflammation involves the assessment of cells and protein levels ("flare") in the aqueous humor. These factors are difficult to quantify precisely on clinical examination alone. Laser flare-cell photometry provides an automated technique to quantify these factors objectively, and it has been used in a variety of research and clinical situations to assess anterior segment inflammation. Any new technique requires evaluation to determine accuracy and reproducibility of measured values, and initial applications require critical appraisal to assess the value of the technique. Both in vitro and in vivo studies of laser flare-cell photometry have been performed to determine its validity and utility as a research and clinical tool. This article reviews published studies that describe the technique of laser flare-cell photometry; it provides new in vitro data that supplements information on the capabilities of this technique and factors that influence photometry results, and it reviews representative publications that have used laser flare-cell photometry for study of specific disease entities. This information can help clinicians and researchers to become familiar with the strengths and limitations of laser flare-cell photometry, to identify appropriate future uses for this technique, and to use it and interpret its results appropriately. Laser flare-cell photometry offers an opportunity to improve upon current techniques of inflammation assessment and should not be considered simply an objective surrogate for clinical grading of cells and flare at the slit-lamp biomicroscope. Its research applications and utility for monitoring patients with uveitis have not yet been fully explored.

  7. New Applications of Lasers in Photobiology and Photochemistry

    NASA Astrophysics Data System (ADS)

    Badr, Y.; Kareim, M. A.

    2005-03-01

    Photonics spectra and optical medical diagnostic field for examination of biological tissues generally and human body specially cover many spectroscopic and laser technologies based on NIR spectroscopy, fluorescence and Raman spectroscopy, Optical coherent tomography (OCT), Confocal microscopy, Opto-acoustic tomography, photon correlation spectroscopy and imaging, and Speckle monitoring of biological flows. The recent achievements in light scattering and coherent light effects in tissues, and in the design of novel lasers and fiber optic techniques for examination of biological tissues are the real motive and the attracting factor for many labs to consider the mentioned above techniques. Our lab, as it contains most of these facilities, started to use these technologies since 1997 in several applications: 1. Applying a suitable setup for introducing exogenous DNA of pAB (with bar/ Gus gene) into cells of embryonic collie of Egyptian wheat based on 193 and 608 nm, 6 ns Excimer laser pulses introducing a modified procedure of Laser-Mediated gene transfer in Egyptian wheat Tridum Aestivum. 2. Applying laser technologies in early identification of abnormal tissues spectroscopically 3. We considered several types of tissues starting with breast cancer, which was subjected to intensive spectroscopic studies using NIR, MIR, FIR, Raman spectroscopy as well as photo-acoustic spectroscopy and imaging studies. Cell carcinoma was considered using Raman spectroscopy and a clear distinction between normal tissue before and after introduction of cell cancer as well as after treating of the tissues using PDT. 4. The application of 193 nm Excimer laser pulse to study photolysis of Acetone using time resolved spectroscopy. A locally designed setup was used to study the effect of delay time (1μs, 2μs, …., 10μs,….,50μs) on the CO and CH3 radicals resulting from the photolysis.

  8. Centimeter-scale MEMS scanning mirrors for high power laser application

    NASA Astrophysics Data System (ADS)

    Senger, F.; Hofmann, U.; v. Wantoch, T.; Mallas, C.; Janes, J.; Benecke, W.; Herwig, Patrick; Gawlitza, P.; Ortega-Delgado, M.; Grune, C.; Hannweber, J.; Wetzig, A.

    2015-02-01

    A higher achievable scan speed and the capability to integrate two scan axes in a very compact device are fundamental advantages of MEMS scanning mirrors over conventional galvanometric scanners. There is a growing demand for biaxial high speed scanning systems complementing the rapid progress of high power lasers for enabling the development of new high throughput manufacturing processes. This paper presents concept, design, fabrication and test of biaxial large aperture MEMS scanning mirrors (LAMM) with aperture sizes up to 20 mm for use in high-power laser applications. To keep static and dynamic deformation of the mirror acceptably low all MEMS mirrors exhibit full substrate thickness of 725 μm. The LAMM-scanners are being vacuum packaged on wafer-level based on a stack of 4 wafers. Scanners with aperture sizes up to 12 mm are designed as a 4-DOF-oscillator with amplitude magnification applying electrostatic actuation for driving a motor-frame. As an example a 7-mm-scanner is presented that achieves an optical scan angle of 32 degrees at 3.2 kHz. LAMM-scanners with apertures sizes of 20 mm are designed as passive high-Q-resonators to be externally excited by low-cost electromagnetic or piezoelectric drives. Multi-layer dielectric coatings with a reflectivity higher than 99.9 % have enabled to apply cw-laser power loads of more than 600 W without damaging the MEMS mirror. Finally, a new excitation concept for resonant scanners is presented providing advantageous shaping of intensity profiles of projected laser patterns without modulating the laser. This is of interest in lighting applications such as automotive laser headlights.

  9. Application of Laser Based Ultrasound for NDE of Damage in Thick Stitched Composites

    NASA Technical Reports Server (NTRS)

    Anastasi, Robert F.; Friedman, Adam D.; Hinders, Mark K.; Madaras, Eric I.

    1997-01-01

    As design engineers implement new composite systems such as thick, load bearing composite structures, they must have certifiable confidence in structure s durability and worthiness. This confidence builds from understanding the structural response and failure characteristics of simple components loaded in testing machines to tests on full scale sections. Nondestructive evaluation is an important element which can provide quantitative information on the damage initiation, propagation, and final failure modes for the composite structural components. Although ultrasound is generally accepted as a test method, the use of conventional ultrasound for in-situ monitoring of damage during tests of large structures is not practical. The use of lasers to both generate and detect ultrasound extends the application of ultrasound to in- situ sensing of damage in a deformed structure remotely and in a non-contact manner. The goal of the present research is to utilize this technology to monitor damage progression during testing. The present paper describes the application of laser based ultrasound to quantify damage in thick stitched composite structural elements to demonstrate the method. This method involves using a Q-switched laser to generate a rapid, local linear thermal strain on the surface of the structure. This local strain causes the generation of ultrasonic waves into the material. A second laser used with a Fabry-Perot interferometer detects the surface deflections. The use of fiber optics provides for eye safety and a convenient method of delivering the laser over long distances to the specimens. The material for these structural elements is composed of several stacks of composite material assembled together by stitching through the laminate thickness that ranging from 0.5 to 0.8 inches. The specimens used for these nondestructive evaluation studies had either impact damage or skin/stiffener interlaminar failure. Although little or no visible surface damage existed

  10. Laser-launched flyer plate and confined laser ablation for shock wave loading: validation and applications.

    PubMed

    Paisley, Dennis L; Luo, Sheng-Nian; Greenfield, Scott R; Koskelo, Aaron C

    2008-02-01

    We present validation and some applications of two laser-driven shock wave loading techniques: laser-launched flyer plate and confined laser ablation. We characterize the flyer plate during flight and the dynamically loaded target with temporally and spatially resolved diagnostics. With transient imaging displacement interferometry, we demonstrate that the planarity (bow and tilt) of the loading induced by a spatially shaped laser pulse is within 2-7 mrad (with an average of 4+/-1 mrad), similar to that in conventional techniques including gas gun loading. Plasma heating of target is negligible, in particular, when a plasma shield is adopted. For flyer plate loading, supported shock waves can be achieved. Temporal shaping of the drive pulse in confined laser ablation allows for flexible loading, e.g., quasi-isentropic, Taylor-wave, and off-Hugoniot loading. These techniques can be utilized to investigate such dynamic responses of materials as Hugoniot elastic limit, plasticity, spall, shock roughness, equation of state, phase transition, and metallurgical characteristics of shock-recovered samples.

  11. Advances in laser-based isotope ratio measurements: selected applications

    NASA Astrophysics Data System (ADS)

    Kerstel, E.; Gianfrani, L.

    2008-09-01

    Small molecules exhibit characteristic ro-vibrational transitions in the near- and mid-infrared spectral regions, which are strongly influenced by isotopic substitution. This gift of nature has made it possible to use laser spectroscopy for the accurate analysis of the isotopic composition of gaseous samples. Nowadays, laser spectroscopy is clearly recognized as a valid alternative to isotope ratio mass spectrometry. Laser-based instruments are leaving the research laboratory stage and are being used by a growing number of isotope researchers for significant advances in their own field of research. In this review article, we discuss the current status and new frontiers of research on high-sensitivity and high-precision laser spectroscopy for isotope ratio analyses. Although many of our comments will be generally applicable to laser isotope ratio analyses in molecules of environmental importance, this paper concerns itself primarily with water and carbon dioxide, two molecules that were studied extensively in our respective laboratories. A complete coverage of the field is practically not feasible in the space constraints of this issue, and in any case doomed to fail, considering the large body of work that has appeared ever since the review by Kerstel in 2004 ( Handbook of Stable Isotope Analytical Techniques, Chapt. 34, pp. 759-787).

  12. Ho-doped fiber for high energy laser applications

    NASA Astrophysics Data System (ADS)

    Friebele, E. Joseph; Askins, Charles G.; Peele, John R.; Wright, Barbara Marcheschi; Condon, Nicholas J.; O'Connor, Shawn; Brown, Christopher G.; Bowman, Steven R.

    2014-03-01

    Ho-doped fiber lasers are of interest for high energy laser applications because they operate in the eye safer wavelength range and in a window of high atmospheric transmission. Because they can be resonantly pumped for low quantum defect operation, thermal management issues are anticipated to be tractable. A key issue that must be addressed in order to achieve high efficiency and minimize thermal issues is parasitic absorption in the fiber itself. Hydroxyl contamination arising from the process for making the Ho-doped fiber core is the principal offender due to a combination band of Si-O and O-H vibrations that absorbs at 2.2 μm in the Ho3+ emission wavelength region. We report significant progress in lowering the OH content to 0.16 ppm, which we believe is a record level. Fiber experiments using a 1.94 μm thulium fiber laser to resonantly clad pump a triple clad Ho-doped core fiber have shown a slope efficiency of 62%, which we also believe is a record for a cladding-pumped laser. Although pump-power limited, the results of these studies demonstrate the feasibility of power scaling Ho-doped fiber lasers well above the currently-reported 400-W level.1

  13. Types of Lasers and Their Applications in Pediatric Dentistry

    PubMed Central

    Nazemisalman, Bahareh; Farsadeghi, Mahya; Sokhansanj, Mehdi

    2015-01-01

    Laser technology has been recently introduced into the dental field with the idea to replace drilling. Having a less painful first dental experience by the use of modern instruments like laser can be an efficient preventive and therapeutic strategy in pediatric dentistry. Pedodontists need to learn the new less invasive technologies and adopt them in their routine practice. This study aimed to review the available types of lasers and their applications in pediatric dentistry. An electronic search was carried out in IranMedex, InterScience, Scopus, Science Direct, PubMed, ProQuest, Medline and Google Scholar databases to find relevant articles published from 2000 to 2014. Relevant textbooks were reviewed as well. Laser can be used as a suitable alternative to many conventional diagnostic and therapeutic dental procedures. It is especially efficient for caries detection and removal, pulp therapy, lowering the risk of infection, inflammation and swelling and reducing bleeding. On the other hand, due to minimal invasion, laser treatment is well tolerated by children. Improved patient cooperation leads to higher satisfaction of the parents, dentists and the children themselves. PMID:26464775

  14. Metal Photocathodes for Free Electron Laser Applications

    NASA Astrophysics Data System (ADS)

    Greaves, Corin Michael Ricardo

    Synchrotron x-ray radiation sources have revolutionized many areas of science from elucidating the atomic structure of proteins to understanding the electronic structure of complex materials such as the cuprate superconductors. In a Free Electron Laser (FEL), the main difference to the synchrotron radiation mechanism is that the light field acts on the electron beam, over a long distance in an undulator, and causes electron bunching at the optical wavelength. Electrons in different parts of the electron bunch are therefore correlated, and so emit coherently, with a brightness that scales as the square of the number of electrons. In order to lase, the electron beam in a FEL must have a transverse geometric emittance less than the wavelength of the light to be produced. For the generation of x-ray wavelengths, this is one of the most difficult challenges in the design and construction of a FEL. The geometric emittance can be "compressed" by acceleration to very high energy, but with the penalty of very large physical size and very large cost. The motivation for this work was provided by the desire to investigate the fundamental origin of the emittance of an electron beam as it is born at a photocathode. If this initial, or "thermal" emittance can be reduced, the energy, scale and cost of accelerators potentially would be reduced. As the LCLS used copper as its photocathode, this material was the one studied in this work. Copper was used in the LCLS as it represented a "robust" material that could stand the very high accelerating gradients used in the photoinjector of the FEL. Metals are also prompt photoemitters, and so can be used to produce very short electron bunches. This can be a useful property for creation of extremely short FEL pulses, and also for creation of beams that are allowed to expand under space charge forces, but in a way that results in linear fields, allowing subsequent recompression. An ideal photocathode for FEL photoinjector should have high

  15. Laser acceleration of low emittance, high energy ions and applications

    NASA Astrophysics Data System (ADS)

    Fuchs, Julien; Audebert, Patrick; Borghesi, Marco; Pépin, Henri; Willi, Oswald

    2009-03-01

    Laser-accelerated ion sources have exceptional properties, i.e. high brightness and high spectral cut-off (56 MeV at present), high directionality and laminarity (at least 100-fold better than conventional accelerators beams), short burst duration (ps). Thanks to these properties, these sources open new opportunities for applications. Among these, we have already explored their use for proton radiography of fields in plasmas and for warm dense matter generation. These sources could also stimulate development of compact ion accelerators or be used for medical applications. To extend the range of applications, ion energy and conversion efficiency must however be increased. Two strategies for doing so using present-day lasers have been successfully explored in LULI experiments. In view of applications, it is also essential to control (i.e. collimate and energy select) these beams. For this purpose, we have developed an ultra-fast laser-triggered micro-lens providing tuneable control of the beam divergence as well as energy selection. To cite this article: J. Fuchs et al., C. R. Physique 10 (2009).

  16. Laser beacon adaptive optics for power beaming applications

    SciTech Connect

    Fugate, R.Q.

    1994-12-31

    This paper discusses the laser beam control system requirements for power beaming applications. Power beaming applications include electric and thermal engine propulsion for orbit transfer, station changing, and recharging batteries. Beam control includes satellite acquisition, high accuracy tracking, higher order atmospheric compensation using adaptive optics, and precision point-ahead. Beam control may also include local laser beam clean-up with a low order adaptive optics system. This paper also presents results of tracking and higher-order correction experiments on astronomical objects. The results were obtained with a laser beacon adaptive optics system at Phillips Laboratory`s Starfire Optical Range near Albuquerque, NM. At a wavelength of 0.85 {mu}m, the author has achieved Strehl ratios of {approximately}0.50 using laser beacons and {approximately}0.65 using natural stars for exposures longer than one minute on objects of {approximately}8{sup th} magnitude. The resulting point spread function has a full width half maximum (FWHM) of 0.13 arcsec.

  17. Geoscience Laser Altimeter System (GLAS): Final Test Report of DM LHP TV Testing. Revised

    NASA Technical Reports Server (NTRS)

    Baker, Charles

    2000-01-01

    The Demonstration Model (DM) Loop Heat Pipe (LHP) was tested at Goddard Space Flight Center (GSFC) during September and October, 1999. The LHP system was placed in the Dynavac 36 in. chamber in Building 4. The test lasted for about 6 weeks. The LHP was built, designed, and manufactured at Dynatherm Corporation, Inc. In Hunt Valley, MD according to GSFC specifications. The purpose of the test was to evaluate the performance of a propylene LHP for the Geoscience Laser Altimetry System (GLAS) instrument application.

  18. Applications of Light Amplification by Stimulated Emission of Radiation (Lasers) for Restorative Dentistry.

    PubMed

    Najeeb, Shariq; Khurshid, Zohaib; Zafar, Muhammad Sohail; Ajlal, Syed

    2016-01-01

    Light amplification by stimulated emission of radiation (laser) has been used widely in a range of biomedical and dental applications in recent years. In the field of restorative dentistry, various kinds of lasers have been developed for diagnostic (e.g. caries detection) and operative applications (e.g. tooth ablation, cavity preparation, restorations, bleaching). The main benefits for laser applications are patient comfort, pain relief and better results for specific applications. Major concerns for using dental lasers frequently are high cost, need for specialized training and sensitivity of the technique, thereby compromising its usefulness particularly in developing countries. The main aim of this paper is to evaluate and summarize the applications of lasers in restorative dentistry, including a comparison of the applications of lasers for major restorative dental procedures and conventional clinical approaches. A remarkable increase in the use of lasers for dental application is expected in the near future. PMID:26642047

  19. Laser assisted die bending: a new application of high power diode lasers

    NASA Astrophysics Data System (ADS)

    Schuöcker, D.; Schumi, T.; Spitzer, O.; Bammer, F.; Schuöcker, G.; Sperrer, G.

    2015-02-01

    Nowadays high power lasers are mainly used for cutting of sheet metals, for welding, hardening and rapid prototyping. In the forming of sheet metals as bending or deep drawing lasers are not used. Nevertheless a few years ago a new application of high power lasers has been invented, where bending of materials that break at room temperature becomes possible by heating them along the bending edge with high power lasers thus allowing their treatment without cracks and rupture. For this purpose a large number of diode lasers are arranged in the bottom tool of a bending machine (a V-shaped die) which heat up the initially flat sheet metal during the bending process what is performed by pressing it into the die with a knife shaped upper tool where due to the laser heating the material is softened and thus cracks are avoided. For the technical realization of the new process of laser assisted die bending, modules equipped with numerous laser diodes and a total beam power of 2,5 kW are used. The light emitted by these modules enters a tool with a length of 15cm and is deflected towards the workpiece. By using ten of these modules with adjacent dies and by integrating those in a bending press a bending edge of sheet metals with a length of 1500mm can be realized. Such a bending press with laser assistance also needs energization with a power of practically 50kW, a respective water flow, a heat exchanger system and also a control for all functions of this system. Special measures have also been developed to avoid radiating of those tools that are not covered by a workpiece in the case of bending edges shorter than the full length of the bending tools whereas individual short circuiting of diode modules can be performed. Specific measures to ensure a safe operation without any harm to the operational person have been realized. Exploitation of the bending process has been carried out for titanium, where material thicknesses up to 3mm have been bent successfully.

  20. Applications of laser-induced gratings to spectroscopy and dynamics

    SciTech Connect

    Rohlfing, E.A.

    1993-12-01

    This program has traditionally emphasized two principal areas of research. The first is the spectroscopic characterization of large-amplitude motion on the ground-state potential surface of small, transient molecules. The second is the reactivity of carbonaceous clusters and its relevance to soot and fullerene formation in combustion. Motivated initially by the desire to find improved methods of obtaining stimulated emission pumping (SEP) spectra of transients, most of our recent work has centered on the use of laser-induced gratings or resonant four-wave mixing in free-jet expansions. These techniques show great promise for several chemical applications, including molecular spectroscopy and photodissociation dynamics. The author describes recent applications of two-color laser-induced grating spectroscopy (LIGS) to obtain background-free SEP spectra of transients and double resonance spectra of nonfluorescing species, and the use of photofragment transient gratings to probe photodissociation dynamics.

  1. Application of a laser trap as a viscometer

    NASA Astrophysics Data System (ADS)

    Cooper, James; Solomon, Rance; Elrod, Samuel; Barnes, Taylor; Crawford, Cameron; Farone, Anthony; Farone, Mary; Erenso, Daniel

    2013-06-01

    A laser tweezer (LT) along with advanced imaging techniques has been widely applied to manipulate and study living as well as nonliving microscopic objects. In this study we present yet another novel application of LTs for a precise measurement of the viscosities of fluids in a micro-volume flow. We have demonstrated this novel application by measuring the viscosity of a fetal bovine serum (FBS) using a LT constructed from a single intensity gradient laser trap. By calibrating the LT using dielectric silica micro-beads in a fluid with a known viscosity, specifically water, and by suspending same size of silica beads in the FBS and trapping with the same trap, we have determined the viscosity of the FBS at different temperatures. We have used the relationship between the trapping and Stoke's drag force for a constant drag speed to determine the viscosity. We have also analyzed the viscosities determined in comparison with corresponding viscosities measured using an Ostwald viscometer.

  2. Study of pseudo noise CW diode laser for ranging applications

    NASA Technical Reports Server (NTRS)

    Lee, Hyo S.; Ramaswami, Ravi

    1992-01-01

    A new Pseudo Random Noise (PN) modulated CW diode laser radar system is being developed for real time ranging of targets at both close and large distances (greater than 10 KM) to satisy a wide range of applications: from robotics to future space applications. Results from computer modeling and statistical analysis, along with some preliminary data obtained from a prototype system, are presented. The received signal is averaged for a short time to recover the target response function. It is found that even with uncooperative targets, based on the design parameters used (200-mW laser and 20-cm receiver), accurate ranging is possible up to about 15 KM, beyond which signal to noise ratio (SNR) becomes too small for real time analog detection.

  3. Recent advances in phosphate laser glasses for high power applications

    SciTech Connect

    Campbell, J.H.

    1996-05-14

    Recent advances in Nd-doped phosphate laser glasses for high-peak-power and high-average-power applications are reviewed. Compositional studies have progressed to the point that glasses can be tailored to have specific properties for specific applications. Non-radiative relaxation effects can be accurately modeled and empirical expressions have been developed to evaluate both intrinsic (structural) and extrinsic (contamination induced) relaxation effects. Losses due to surface scattering and bulk glass absorption have been carefully measured and can be accurately predicted. Improvements in processing have lead to high damage threshold (e.g. Pt inclusion free) and high thermal shock resistant glasses with improved edge claddings. High optical quality pieces up to 79 x 45 x 4cm{sup 3} have been made and methods for continuous melting laser glass are under development.

  4. Novel oral applications of ultra-short laser pulses

    NASA Astrophysics Data System (ADS)

    Wieger, V.; Wernisch, J.; Wintner, E.

    2007-02-01

    In the past decades, many efforts have been made to replace mechanical tools in oral applications by various laser systems. The reasons therefore are manifold: i) Friction causes high temperatures damaging adjacent tissue. ii) Smear layers and rough surfaces are produced. iii) Size and shape of traditional tools are often unsuitable for geometrically complicated incisions and for minimum invasive treatment. iv) Mechanical damage of the remaining tissue occurs. v) Online diagnosis for feedback is not available. Different laser systems in the µs and sub-&mrgs-pulse regime, among them Erbium lasers, have been tested in the hope to overcome the mentioned drawbacks and, to some extent, they represent the current state of the art with respect to commercial and hence practical application. In the present work the applicability of scanned ultrashort pulse lasers (USPLs) for biological hard tissue as well as dental restoration material removal was tested. It is shown that cavities with features superior to mechanically treated or Erbium laser ablated cavities can be generated if appropriate scan algorithms and optimum laser parameters are matched. Smooth cavity rims, no microcracks, melting or carbonisation and precise geometry are the advantages of scanned USLP ablation. For bone treatment better healing conditions are expected as the natural structure remains unaffected by the preparation procedure. The novelty of this work is represented by a comprehensive compilation of various experimental results intended to assess the performance of USPLs. In this context, various pulse durations in the picosecond and femtosecond regime were applied to dental and bone tissue as well as dental restoration materials which is considered to be indispensable for a complete assessment. Parameters like ablation rates describing the efficiency of the ablation process, and ablation thresholds were determined - some of them for the first time - and compared to the corresponding Erbium

  5. Characterization of holmium fibers with various concentrations for fiber laser applications around 2.1 μm

    NASA Astrophysics Data System (ADS)

    Aubrecht, Jan; Peterka, Pavel; Honzatko, Pavel; Baravets, Yauhen; Jelinek, Michal; Kubecek, Vaclav; Pawliszewska, Maria; Sotor, Jaroslaw; Sobon, Grzegorz; Abramski, Krzysztof M.; Kasik, Ivan

    2016-04-01

    In this work, we present experimental results of characterization of the developed holmium-doped silica-based optical fibers with holmium ions concentrations in the range from 1000 to 10000 ppm. The fibers were fabricated by the modified chemical vapor deposition and solution doping method. They were characterized in terms of their spectral attenuation, refractive index profile, and especially performance in fiber laser. Simultaneously, two different fiber laser setups were tested. In the first one, holmium-doped fiber in Fabry-Perot configuration was pumping by in house developed thulium-doped fiber laser in ring arrangement. In the second one, bulk-optic pump-coupling configuration, consisted of a commercially available thulium fiber laser emitting at 1940 nm and system of lenses and mirrors was used. We have focused on comparison of laser output powers, slope efficiencies, and laser thresholds for individual holmiumdoped fiber in these different laser arrangements. Finally, the application of the developed fiber in subpicosecond fiber laser with graphene-based saturable absorber for mode-locking operation was investigated.

  6. Laser produced plasma diagnostics by cavity ringdown spectroscopy and applications

    SciTech Connect

    Milosevic, S.

    2012-05-25

    Laser-produced plasmas have many applications for which detailed characterization of the plume is requested. Cavity ring-down spectroscopy is a versatile absorption method which provides data on the plume and its surroundings, with spatial and temporal resolution. The measured absorption line shapes contain information about angular and velocity distributions within the plume. In various plasmas we have observed molecules or metastable atoms which were not present in the emission spectra.

  7. High power fiber delivery for laser ignition applications.

    PubMed

    Yalin, Azer P

    2013-11-01

    The present contribution provides a concise review of high power fiber delivery research for laser ignition applications. The fiber delivery requirements are discussed in terms of exit energy, intensity, and beam quality. Past research using hollow core fibers, solid step-index fibers, and photonic crystal and bandgap fibers is summarized. Recent demonstrations of spark delivery using large clad step-index fibers and Kagome photonic bandgap fibers are highlighted.

  8. Development of long wavelength single longitudinal (SLM) injection laser diodes. Final technical report, November 1979-December 1980

    SciTech Connect

    Speer, F.D.; Stockton, T.E.

    1980-12-30

    Development of Long Wavelength Single Longitudinal (SLM) Injection Laser Diodes emitting in the 1.3 micron region, utilizing a buried heterojunction BH structure is described. This final report describes efforts directed toward the development and optimization of these type devices and, in particular, concentrates on the following points: (1) Optimization of the double heterojunction DH structure; (2) Process development connected with the fabrication of buried heterojunction BH laser structures; (3) Modification BH laser structure and fabrication technique to optimize severe melt back; (4) Modification of the regrowth LPE technique to resolve melt back and the optimization of the N-P reverse bias junctions; and (5) Device performance.

  9. Infrared glass fiber cables for CO laser medical applications

    NASA Astrophysics Data System (ADS)

    Arai, Tsunenori; Mizuno, Kyoichi; Sensaki, Koji; Kikuchi, Makoto; Watanabe, Tamishige; Utsumi, Atsushi; Takeuchi, Kiyoshi; Akai, Yoshiro

    1993-05-01

    We developed the medical fiber cables which were designed for CO laser therapy, i.e., angioplasty and endoscopic therapy. As-S chalcogenide glass fibers were used for CO laser delivery. A 230 micrometers core-diameter fiber was used for the angioplasty laser cable. The outer diameter of this cable was 600 micrometers . The total length and insertion length of the angioplasty laser cable were 2.5 m and 1.0 m, respectively. Typically, 2.0 W of fiber output was used in the animal experiment in vivo for the ablation of the model plaque which consisted of human atheromatous aorta wall. The transmission of the angioplasty laser cable was approximately 35%, because the reflection loss occurred at both ends of the fiber and window. Meanwhile, the core diameter of the energy delivery fiber for the endoscopic therapy was 450 micrometers . The outer diameter of this cable was 1.7 mm. Approximately 4.5 W of fiber output was used for clinical treatment of pneumothorax through a pneumoscope. Both types of the cables had the ultra-thin thermocouples for temperature monitoring at the tip of the cables. This temperature monitoring was extremely useful to prevent the thermal destruction of the fiber tip. Moreover, the As-S glass fibers were completely sealed by the CaF2 windows and outer tubes. Therefore, these cables were considered to have sufficient safety properties for medical applications. These laser cables were successfully used for the in vivo animal experiments and/or actual clinical therapies.

  10. Ultra-stable clock laser system development towards space applications

    NASA Astrophysics Data System (ADS)

    Świerad, Dariusz; Häfner, Sebastian; Vogt, Stefan; Venon, Bertrand; Holleville, David; Bize, Sébastien; Kulosa, André; Bode, Sebastian; Singh, Yeshpal; Bongs, Kai; Rasel, Ernst Maria; Lodewyck, Jérôme; Le Targat, Rodolphe; Lisdat, Christian; Sterr, Uwe

    2016-09-01

    The increasing performance of optical lattice clocks has made them attractive for scientific applications in space and thus has pushed the development of their components including the interrogation lasers of the clock transitions towards being suitable for space, which amongst others requires making them more power efficient, radiation hardened, smaller, lighter as well as more mechanically stable. Here we present the development towards a space-compatible interrogation laser system for a strontium lattice clock constructed within the Space Optical Clock (SOC2) project where we have concentrated on mechanical rigidity and size. The laser reaches a fractional frequency instability of 7.9 × 10‑16 at 300 ms averaging time. The laser system uses a single extended cavity diode laser that gives enough power for interrogating the atoms, frequency comparison by a frequency comb and diagnostics. It includes fibre link stabilisation to the atomic package and to the comb. The optics module containing the laser has dimensions 60 × 45 × 8 cm3 and the ultra-stable reference cavity used for frequency stabilisation with its vacuum system takes 30 × 30 × 30 cm3. The acceleration sensitivities in three orthogonal directions of the cavity are 3.6 × 10‑10/g, 5.8 × 10‑10/g and 3.1 × 10‑10/g, where g ≈ 9.8 m/s2 is the standard gravitational acceleration.

  11. Proposal of a defense application for a chemical oxygen laser

    NASA Astrophysics Data System (ADS)

    Takehisa, K.

    2015-05-01

    Defense application for a chemical oxygen laser (COL) is explained. Although a COL has not yet been successful in lasing, the oscillator was estimated to produce a giant pulse with the full width at half maximum (FWHM) of ~0.05ms which makes the damage threshold for the mirrors several-order higher than that for a typical solid-state laser with a ~10ns pulse width. Therefore it has a potential to produce MJ class output considering the simple scalability of being a chemical laser. Since within 0.05ms a supersonic aircraft can move only a few centimeters which is roughly equal to the spot size of the focused beam at ~10km away using a large-diameter focusing mirror, a COL has a potential to make a damage to an enemy aircraft by a single shot without beam tracking. But since the extracted beam can propagate up to a few kilometers due to the absorption in the air, it may be suitable to use in space. While a chemical oxygen-iodine laser (COIL) can give a pulsed output with a width of ~2 ms using a high-pressure singlet oxygen generator (SOG). Therefore a pulsed COIL may also not require beam tracking if a target aircraft is approaching. Another advantage for these pulsed high-energy lasers (HELs) is that, in case of propagating in cloud or fog, much less energy is required for a laser for aerosol vaporization (LAV) than that of a LAV for a CW HEL. Considerations to use a COL as a directed energy weapon (DEW) in a point defense system are shown.

  12. Ultra-stable clock laser system development towards space applications

    PubMed Central

    Świerad, Dariusz; Häfner, Sebastian; Vogt, Stefan; Venon, Bertrand; Holleville, David; Bize, Sébastien; Kulosa, André; Bode, Sebastian; Singh, Yeshpal; Bongs, Kai; Rasel, Ernst Maria; Lodewyck, Jérôme; Le Targat, Rodolphe; Lisdat, Christian; Sterr, Uwe

    2016-01-01

    The increasing performance of optical lattice clocks has made them attractive for scientific applications in space and thus has pushed the development of their components including the interrogation lasers of the clock transitions towards being suitable for space, which amongst others requires making them more power efficient, radiation hardened, smaller, lighter as well as more mechanically stable. Here we present the development towards a space-compatible interrogation laser system for a strontium lattice clock constructed within the Space Optical Clock (SOC2) project where we have concentrated on mechanical rigidity and size. The laser reaches a fractional frequency instability of 7.9 × 10−16 at 300 ms averaging time. The laser system uses a single extended cavity diode laser that gives enough power for interrogating the atoms, frequency comparison by a frequency comb and diagnostics. It includes fibre link stabilisation to the atomic package and to the comb. The optics module containing the laser has dimensions 60 × 45 × 8 cm3; and the ultra-stable reference cavity used for frequency stabilisation with its vacuum system takes 30 × 30 × 30 cm3. The acceleration sensitivities in three orthogonal directions of the cavity are 3.6 × 10−10/g, 5.8 × 10−10/g and 3.1 × 10−10/g, where g ≈ 9.8 m/s2 is the standard gravitational acceleration. PMID:27667640

  13. Laser Propulsion - Quo Vadis

    SciTech Connect

    Bohn, Willy L.

    2008-04-28

    First, an introductory overview of the different types of laser propulsion techniques will be given and illustrated by some historical examples. Second, laser devices available for basic experiments will be reviewed ranging from low power lasers sources to inertial confinement laser facilities. Subsequently, a status of work will show the impasse in which the laser propulsion community is currently engaged. Revisiting the basic relations leads to new avenues in ablative and direct laser propulsion for ground based and space based applications. Hereby, special attention will be devoted to the impact of emerging ultra-short pulse lasers on the coupling coefficient and specific impulse. In particular, laser sources and laser propulsion techniques will be tested in microgravity environment. A novel approach to debris removal will be discussed with respect to the Satellite Laser Ranging (SRL) facilities. Finally, some non technical issues will be raised aimed at the future prospects of laser propulsion in the international community.

  14. Compact atomic clocks and stabilised laser for space applications

    NASA Astrophysics Data System (ADS)

    Mileti, Gaetano; Affolderbach, Christoph; Matthey-de-l'Endroit, Renaud

    2016-07-01

    We present our developments towards next generation compact vapour-cell based atomic frequency standards using a tunable laser diode instead of a traditional discharge lamp. The realisation of two types of Rubidium clocks addressing specific applications is in progress: high performance frequency standards for demanding applications such as satellite navigation, and chip-scale atomic clocks, allowing further miniaturisation of the system. The stabilised laser source constitutes the main technological novelty of these new standards, allowing a more efficient preparation and interrogation of the atoms and hence an improvement of the clock performances. However, before this key component may be employed in a commercial and ultimately in a space-qualified instrument, further studies are necessary to demonstrate their suitability, in particular concerning their reliability and long-term operation. The talk will present our preliminary investigations on this subject. The stabilised laser diode technology developed for our atomic clocks has several other applications on ground and in space. We will conclude our talk by illustrating this for the example of a recently completed ESA project on a 1.6 microns wavelength reference for a future space-borne Lidar. This source is based on a Rubidium vapour cell providing the necessary stability and accuracy, while a second harmonic generator and a compact optical comb generated from an electro-optic modulator allow to transfer these properties from the Rubidium wavelength (780nm) to the desired spectral range.

  15. Fossil fuel characterization using laser desorption mass spectrometry: Applications and limitations

    SciTech Connect

    Hunt, J.E.; Winans, R.E.

    1995-08-01

    Laser desorption mass spectroscopy (LDMS) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI) are applicable to the high molecular weight compounds in fossil fuels which resist intact ionization. LD or MALDI of coals and extracts do not show reproducible ion intensity over mass 2000. This paper describes the scope and limitations of LD and MALD in time-of-flight mass spectrometers applied to high molecular weight molecules such as proteins and polymers. Coal was also analyzed. It is concluded that the sample preparation step is perhaps the most important part in MALDI. Observed high mass ions in coal may be from contaminant proteins. Optimal matrices must be found. Finally, the mass spectrum is senstive to number average molecular weight; a low value, however, does not preclude presence of high molecular weight species.

  16. Laser Isotope Enrichment for Medical and Industrial Applications

    SciTech Connect

    Leonard Bond

    2006-07-01

    Laser Isotope Enrichment for Medical and Industrial Applications by Jeff Eerkens (University of Missouri), Jay Kunze (Idaho State University), and Leonard Bond (Idaho National Laboratory) The principal isotope enrichment business in the world is the enrichment of uranium for commercial power reactor fuels. However, there are a number of other needs for separated isotopes. Some examples are: 1) Pure isotopic targets for irradiation to produce medical radioisotopes. 2) Pure isotopes for semiconductors. 3) Low neutron capture isotopes for various uses in nuclear reactors. 4) Isotopes for industrial tracer/identification applications. Examples of interest to medicine are targets to produce radio-isotopes such as S-33, Mo-98, Mo-100, W-186, Sn-112; while for MRI diagnostics, the non-radioactive Xe-129 isotope is wanted. For super-semiconductor applications some desired industrial isotopes are Si-28, Ga-69, Ge-74, Se-80, Te-128, etc. An example of a low cross section isotope for use in reactors is Zn-68 as a corrosion inhibitor material in nuclear reactor primary systems. Neutron activation of Ar isotopes is of interest in industrial tracer and diagnostic applications (e.g. oil-logging). . In the past few years there has been a sufficient supply of isotopes in common demand, because of huge Russian stockpiles produced with old electromagnetic and centrifuge separators previously used for uranium enrichment. Production of specialized isotopes in the USA has been largely accomplished using old ”calutrons” (electromagnetic separators) at Oak Ridge National Laboratory. These methods of separating isotopes are rather energy inefficient. Use of lasers for isotope separation has been considered for many decades. None of the proposed methods have attained sufficient proof of principal status to be economically attractive to pursue commercially. Some of the authors have succeeded in separating sulfur isotopes using a rather new and different method, known as condensation

  17. Application of ring lasers to determine the directions to the poles of Earth's rotation

    SciTech Connect

    Golyaev, Yu D; Kolbas, Yu Yu

    2012-10-31

    Application of a ring laser to determine the directions to the poles of Earth's rotation is considered. The maximum accuracy of determining the directions is calculated, physical and technical mechanisms that limit the accuracy are analysed, and the instrumental errors are estimated by the example of ring He - Ne lasers with Zeeman biasing. (laser applications and other topics in quantum electronics)

  18. High Final Energy of Low-Level Gallium Arsenide Laser Therapy Enhances Skeletal Muscle Recovery without a Positive Effect on Collagen Remodeling.

    PubMed

    de Freitas, Carlos Eduardo Assumpção; Bertaglia, Raquel Santilone; Vechetti Júnior, Ivan José; Mareco, Edson Assunção; Salomão, Rondinelle Artur Simões; de Paula, Tassiana Gutierrez; Nai, Gisele Alborghetti; Carvalho, Robson Francisco; Pacagnelli, Francis Lopes; Dal-Pai-Silva, Maeli

    2015-01-01

    The aim of this study was to evaluate the effects of a Gallium Arsenide (GaAs) laser, using a high final energy of 4.8 J, during muscle regeneration after cryoinjury. Thirty Wistar rats were divided into three groups: Control (C, n = 10); Injured (I, n = 10) and Injured and laser treated (Injured/LLLT, n = 10). The cryoinjury was induced in the central region of the tibialis anterior muscle (TA). The applications of the laser (904 nm, 50 mW average power) were initiated 24 h after injury, at energy density of 69 J cm(-1) for 48 s, for 5 days, to two points of the lesion. Twenty-four hours after the final application, the TA muscle was removed and frozen in liquid nitrogen to assess the general muscle morphology and the gene expression of TNF-α, TGF-β, MyoD, and Myogenin. The Injured/LLLT group presented a higher number of regenerating fibers and fewer degenerating fibers (P < 0.05) without changes in the collagen remodeling. In addition, the Injured/LLLT group presented a significant decrease in the expression of TNF-α and myogenin compared to the injured group (P < 0.05). The results suggest that the GaAs laser, using a high final energy after cryoinjury, promotes muscle recovery without changing the collagen remodeling in the muscle extracellular matrix.

  19. Applications of laser diagnostics in energy conservation research

    SciTech Connect

    Hutchinson, R.A.

    1985-02-01

    During the past decade, intensive research and development has demonstrated the feasibility, checked the accuracy, and extended the sensitivity of laser diagnostics for combustion systems. Combinations of diagnostics can now provide in-situ, time-, and space-resolved measurements of temperature, velocity, and species concentration. Although these tools are powerful, they also can be exceedingly difficult to use, and their application remains largely in the hands of specialized instrument developers rather than problem-oriented researchers. This report outlines a variety of applications for existing diagnostics that may interest both instrument developers and researchers in particular fields.

  20. Grazing incidence liquid metal mirrors (GILMM) for radiation hardened final optics for laser inertial fusion energy power plants

    SciTech Connect

    Moir, R W

    1999-06-30

    A thin film of liquid metal is suggested as a grazing incident liquid metal mirror (GILMM) for robust final optics of a laser inertial fusion energy (IFE) power plant. The amount of laser light the mirror can withstand, called the damage limit, of a sodium film 85{sup o} from normal is calculated to be 57 J/cm{sup 2} normal to the beam for a 20 ns pulse and 1.3 J/cm{sup 2} for a 10 ps pulse of 0.35 {micro}m light (2 m{sup 2} and 90 m{sup 2} of mirror area per 100 kJ of laser energy at 20 ns and 10 ps, respectively). Feasibility relies on keep the liquid surface flat to the required accuracy by a combination of polished substrate, adaptive (deformable) optics, surface tension and low Reynolds number, laminar flow in the film. The film's substrate must be polished to {+-} 0.015 pm. Then surface tension keeps the surface smooth over short distances (<10 mm) and low Reynolds number laminar flow keeps the surface smooth by keeping the film thickness constant to less than + 0.01 w over long distance >10 mm. Adaptive optics techniques keep. the substrate flat to within {+-} 0.06 pm over 100 mm distance and {+-}0.6 {micro}m over 1000 mm distances. The mirror can stand the x-ray pulse when located 30 m away from the microexplosions of nominal yield of 400 MJ (50 MJ of X rays) when Li is used but for higher atomic number liquids like Na there may be too high a temperature rise forcing use of other x-ray attenuation methods such as attenuation by xenon gas. The cumulative damage from neutrons causing warpage of the liquid film's substrate can be compensated by adaptive optics techniques giving the mirrors long life, perhaps 30 years. The GILMM should be applicable to both direct and indirect drive and pulse lengths appropriate to slow compression ({approx}20 ns) or fast ignition ({approx}10 ps). For direct drive laser beams near the poles (70{sup o}, where 90{sup o} is vertical), stable thin films become more challenging. Proof of concept experiments are needed to verify the

  1. Application and Network-Cognizant Proxies - Final Report

    SciTech Connect

    Antonio Ortega; Daniel C. Lee

    2003-03-24

    OAK B264 Application and Network-Cognizant Proxies - Final Report. Current networks show increasing heterogeneity both in terms of their bandwidths/delays and the applications they are required to support. This is a trend that is likely to intensify in the future, as real-time services, such as video, become more widely available and networking access over wireless links becomes more widespread. For this reason they propose that application-specific proxies, intermediate network nodes that broker the interactions between server and client, will become an increasingly important network element. These proxies will allow adaptation to changes in network characteristics without requiring a direct intervention of either server or client. Moreover, it will be possible to locate these proxies strategically at those points where a mismatch occurs between subdomains (for example, a proxy could be placed so as to act as a bridge between a reliable network domain and an unreliable one). This design philosophy favors scalability in the sense that the basic network infrastructure can remain unchanged while new functionality can be added to proxies, as required by the applications. While proxies can perform numerous generic functions, such as caching or security, they concentrate here on media-specific, and in particular video-specific, tasks. The goal of this project was to demonstrate that application- and network-specific knowledge at a proxy can improve overall performance especially under changing network conditions. They summarize below the work performed to address these issues. Particular effort was spent in studying caching techniques and on video classification to enable DiffServ delivery. other work included analysis of traffic characteristics, optimized media scheduling, coding techniques based on multiple description coding, and use of proxies to reduce computation costs. This work covered much of what was originally proposed but with a necessarily reduced scope.

  2. Experimental grounds for YAG:Er laser application to dentistry

    NASA Astrophysics Data System (ADS)

    Bol'shakov, E. N.; Dolgikh, Robert A.; Zazulevskaya, Lidiya Y.; Zubov, Boris V.; Lobachyov, V. A.; Murina, T. M.; Prokhorov, Alexander M.

    1990-09-01

    Stornatologic service is most popular of all kinds of medical aid, since up to 90% of people suffer from caries, parodontosis holds the second place after such a widespread disease as cardiovascular pathology. The treatment of the tooth hard tissue, intervention into pulp and parodontium using conventional methods are accompanied with painfulness and unpleasant sensation. A lack of efficient methods of anesthesia and pulp devitalization, a high percentage of complica tions after pulpitis treatment made it necessary to search for new methods of treatment which exclude these negative aspects. Application of laser radiation may be one of the ways in resolving this problem. Such attempts have been made repeatedly with the development of laser technology.'3 However, not all of them turned out to be successful. The greatest difficulties occurred on surgical intervention into hard tooth tissue. The best results have been so far attained when using pulsed CO2 laser operated at the wavelength A =1O.61um. For instance, at pulse width 1O1us and frequency 10-20 Hz, the tooth channel drilling was efficient at energy density in pulse P . 10 JIcm2. 4'5 The electron-microscopic investigations have proved the tooth microstructure to be preserved for this laser operation mode. The traces of graphitization were observed only in the vicinity of the lateral walls of the channel.

  3. Application of lasers and pulsed power to coating removal

    NASA Astrophysics Data System (ADS)

    Young, Chris M.; Moeny, William M.; Curry, Randy D.; McDonald, Ken; Bosma, John T.

    1995-03-01

    Lasers and other pulsed power systems are uniquely suited for removal of coatings from a wide variety of substrates. Coatings which can be removed by these systems include paint, adhesives, epoxies, dips, rust, scale, and bird droppings. Suitable substrates include wood, metal, cloth, stone, ceramic, plastics, and even skin. These systems have the advantage over chemical stripping or mechanical abrasion in that the substrate is left virtually unharmed and in many cases the residue is reduced to a form that is more easily disposed of without toxic byproducts or expensive refurbishment. Furthermore, laser and other pulsed power based systems can be operated using only local containment without the need for special operator protective gear or complete enclosure of the substrate structure. Additional advantages are gained in these systems because they typically combine multiple removal mechanisms for greater effectiveness. For example, pulsed lasers create rapid heating of the coating. This rapid heating can result in chemical breakdown of the coating, thermomechanical stress induced dislocation, shock wave agitation, and physical ablation. This paper presents some of the latest research findings on coating removal using these systems. A comparative survey of the system technology, effectiveness, cost, and application is presented. Also presented is a survey of the commercial potential for the systems. Systems which are presented include lasers (CW, pulsed, Infrared, UV, etc.), flashlamps, electro-cathodic debonders, electron beams, and glow discharges.

  4. A new compact laser source for portable LIBS applications

    NASA Astrophysics Data System (ADS)

    Goujon, J.; Musset, O.; Giakoumaki, A.; Pinon, V.; Anglos, D.; Georgiou, E.

    2008-02-01

    We present LIBS experimental results that demonstrate the use of a newly compact, versatile pulsed laser source in material analysis in view of research aiming at the development of portable LIBS instrumentation. LIBS qualitative analyses were performed on various samples and objects, and spectra were recorded in gated and non-gated modes. The latter is important because of advantages arising from size and cost reduction when using simple, compact spectrograph-CCD detection systems over the standard ICCD-based configurations. The new Nd 3+:YAG laser source exhibited very reliable performance in terms of laser pulse repeatability, autonomy and interface. Indeed, it can deliver a 45 mJ for 4.5 ns pulse and work at 1 Hz. Having the ability to work in double-pulse mode, it provided versatility in the measurements leading to increased LIBS signal intensities, improved the signal noise ratio and stabilized spectra. The first test results are encouraging and demonstrate that this new laser is suitable for integration in compact, portable and low cost LIBS sensors with a wide spectrum of materials analysis applications.

  5. Three-dimensional laser window formation for industrial application

    NASA Technical Reports Server (NTRS)

    Verhoff, Vincent G.; Kowalski, David

    1993-01-01

    The NASA Lewis Research Center has developed and implemented a unique process for forming flawless three-dimensional, compound-curvature laser windows to extreme accuracies. These windows represent an integral component of specialized nonintrusive laser data acquisition systems that are used in a variety of compressor and turbine research testing facilities. These windows are molded to the flow surface profile of turbine and compressor casings and are required to withstand extremely high pressures and temperatures. This method of glass formation could also be used to form compound-curvature mirrors that would require little polishing and for a variety of industrial applications, including research view ports for testing devices and view ports for factory machines with compound-curvature casings. Currently, sodium-alumino-silicate glass is recommended for three-dimensional laser windows because of its high strength due to chemical strengthening and its optical clarity. This paper discusses the main aspects of three-dimensional laser window formation. It focuses on the unique methodology and the peculiarities that are associated with the formation of these windows.

  6. Diffusing fiber tips for high-power medical laser applications

    NASA Astrophysics Data System (ADS)

    Schmitz, Christoph H.; Spaniol, Stefan B.; Abraham, Volkhard; Ashraf, Naim; Neuberger, Wolfgang; Ertmer, Wolfgang

    1995-01-01

    For most applications in laser medicine suitable delivery systems are required. We developed fiber optic based diffusing tips especially for photodynamic therapy (PDT) and laser induced thermotherapy (LITT). To realize an adequate emitting cylindrical diffuser the fiber core was abraded by a precision cutter. Hence, the use of scattering media such as TiO2-doped polymers is avoided. Because the diffuser size is mainly determined by the manipulated fiber and a surrounding glass capillary, one can realize small diameters ((phi) approximately equals 3 mm). The laser light is distributed mainly by surface scattering and total reflection at the fiber air boundary. Because the use of absorbing media is avoided, it is possible to apply high laser power as necessary in LITT and pulsed PDT. We produced diffusing tips with lengths of several centimeters and typical diameters of 3 mm. By controlling the fiber-shaping process, a homogeneous intensity profile or even special designs can be achieved. The control is done by either on-line camera surveillance or calculated predictions. A delivery system especially for the photodynamical treatment of female cervix dysplasia has been designed.

  7. Novel Applications of Laser Doppler Vibration Measurements to Medical Imaging

    NASA Astrophysics Data System (ADS)

    Tabatabai, Habib; Oliver, David E.; Rohrbaugh, John W.; Papadopoulos, Christopher

    2013-06-01

    Laser Doppler Vibrometry (LDV) has been widely used in engineering applications involving non-contact vibration and sound measurements. This technique has also been used in some biomedical applications including hearing research. The detectable frequencies are in the range of near-DC to 1 GHz or higher. This paper reviews applications of LDV in biomedical engineering and proposes new medical imaging applications based on measuring surface vibrations of tissues and organs. Tests were conducted on human skin using single point and scanning laser vibrometers. These tests suggest that skin vibrations due to the forcing excitation from the heart can be used in imaging of blood flow. The results of these tests illustrate the potential of such vibration measurements in a variety of diagnostic medical imaging applications including blood flow/restrictions, real-time monitoring of blood pressure variations, wound healing, muscle movements, etc. The fact that the measurements can be conducted remotely (non-contact) is an important benefit that adds to the promise of this approach.

  8. Development of techniques required for the application of a laser to three dimensional visual sensing

    NASA Technical Reports Server (NTRS)

    Ryan, Arthur M.; Gerhardt, Lester A.

    1991-01-01

    The ongoing vision research at the Center for Intelligent Robotic Systems for Space Exploration (CIRSSE) is directed toward identifying and addressing the relevant issues involved in applying visual sensing to space assembly tasks. A considerable amount of effort has been devoted to passive sensing techniques such as using multiple cameras to identify objects in a scene. To compliment the capabilities of the passive visual system in the CIRSSE robotics testbed, research is being conducted in active sensing techniques. This report is description of the research associated with the testbed's laser scanner and its application as an active sensing device. The report is comprised of five major topics. First is a brief description of the CIRSSE visual system and a summary of the active sensing research that has been conducted up to this point. Second, some of the methods currently used to calibrate CIRSSE's laser scanner are described as well as an appraisal of the effectiveness of these methods. Third, is a discussion of how the laser scanner can be employed in concert with a camera to provide a three dimensional point estimation capability. Fourth, there is a description of methods that can be used to detect the presence of the laser beam in a cluttered camera image. Finally, there is a summary of the current state of this research and a description of research planned for the future.

  9. Surface-assisted laser desorption ionization mass spectrometry techniques for application in forensics.

    PubMed

    Guinan, Taryn; Kirkbride, Paul; Pigou, Paul E; Ronci, Maurizio; Kobus, Hilton; Voelcker, Nicolas H

    2015-01-01

    Matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS) is an excellent analytical technique for the rapid and sensitive analysis of macromolecules (>700 Da), such as peptides, proteins, nucleic acids, and synthetic polymers. However, the detection of smaller organic molecules with masses below 700 Da using MALDI-MS is challenging due to the appearance of matrix adducts and matrix fragment peaks in the same spectral range. Recently, nanostructured substrates have been developed that facilitate matrix-free laser desorption ionization (LDI), contributing to an emerging analytical paradigm referred to as surface-assisted laser desorption ionization (SALDI) MS. Since SALDI enables the detection of small organic molecules, it is rapidly growing in popularity, including in the field of forensics. At the same time, SALDI also holds significant potential as a high throughput analytical tool in roadside, work place and athlete drug testing. In this review, we discuss recent advances in SALDI techniques such as desorption ionization on porous silicon (DIOS), nano-initiator mass spectrometry (NIMS) and nano assisted laser desorption ionization (NALDI™) and compare their strengths and weaknesses with particular focus on forensic applications. These include the detection of illicit drug molecules and their metabolites in biological matrices and small molecule detection from forensic samples including banknotes and fingerprints. Finally, the review highlights recent advances in mass spectrometry imaging (MSI) using SALDI techniques.

  10. Aerodynamic distortion propagation calculation in application of high-speed target detection by laser

    NASA Astrophysics Data System (ADS)

    Zheng, Yonghui; Sun, Huayan; Zhao, Yanzhong; Chen, Jianbiao

    2015-10-01

    Active laser detection technique has a broad application prospect in antimissile and air defense, however the aerodynamic flow field around the planes and missiles cause serious distortion effect on the detecting laser beams. There are many computational fluid dynamics(CFD) codes that can predict the air density distribution and also the density fluctuations of the flow field, it's necessary for physical optics to be used to predict the distortion properties after propagation through the complex process. Aiming at the physical process of laser propagation in "Cat-eye" lenses and aerodynamic flow field for twice, distortion propagation calculation method is researched in this paper. In the minds of dividing the whole process into two parts, and tread the aero-optical optical path difference as a phase distortion, the incidence and reflection process are calculated using Collins formula and angular spectrum diffraction theory respectively. In addition, turbulent performance of the aerodynamic flow field is estimated according to the electromagnetic propagation theory through a random medium, the rms optical path difference and Strehl ratio of the turbulent optical distortion are obtained. Finally, Computational fluid mechanics and aero-optical distortion properties of the detecting laser beams are calculated with the hemisphere-on-cylinder turret as an example, calculation results are showed and analysed.

  11. Performance analysis and characterization of the Lumonics Inc. HyperDYE-300 laser-pumped dye laser. Final technical report

    SciTech Connect

    Taylor, T.S.; Davenport, W.E.; Ehrlich, J.J.

    1990-07-11

    The laser analyzed in this research, the Lumonics, Inc. HyperDYE-300 laser pumped dye laser, was procured via the FSTC D650 Program and was characterized in order to support the technology development of that program. The dye laser was pumped with a Neodymium:YAG q-switched laser and it utilized Rhodamine-6G in methanol. It was found to be tunable from about 545 nm to 590 nm and produced a maximum ouput energy of 56 percent of the pump beam energy. The analysis involved the measuring of optimum dye/solvent concentration, output energy versus tunability, optical efficiency versus tunability, temporal and spatial profiles, beam divergence, linewidth, and amplified spontaneous emission versus laser emission.

  12. ELIMED, future hadrontherapy applications of laser-accelerated beams

    NASA Astrophysics Data System (ADS)

    Cirrone, Giuseppe A. P.; Carpinelli, Massimo; Cuttone, Giacomo; Gammino, Santo; Bijan Jia, S.; Korn, Georg; Maggiore, Mario; Manti, Lorenzo; Margarone, Daniele; Prokupek, Jan; Renis, Marcella; Romano, Francesco; Schillaci, Francesco; Tomasello, Barbara; Torrisi, Lorenzo; Tramontana, Antonella; Velyhan, Andriy

    2013-12-01

    Laser-ion acceleration has recently gained a great interest as an alternative to conventional and more expensive acceleration techniques. These ion beams have desirable qualities such as small source size, high luminosity and small emittance to be used in different fields as Nuclear Physics, Medical Physics, etc. This is very promising specially for the future perspective of a new concept of hadrontherapy based on laser-based devices could be developed, replacing traditional accelerating machines. Before delivering laser-driven beams for treatments they have to be handled, cleaned from unwanted particles and characterized in order to have the clinical requirements. In fact ion energy spectra have exponential trend, almost 100% energy spread and a wide angular divergence which is the biggest issue in the beam transport and, hence, in a wider use of this technology. In order to demonstrate the clinical applicability of laser-driven beams new collaboration between ELI-Beamlines project researchers from Prague (Cz) and a INFN-LNS group from Catania (I) has been already launched and scientists from different countries have already express their will in joining the project. This cooperation has been named ELIMED (MEDical application at ELIBeamlines) and will take place inside the ELI-Beamlines infrastructure located in Prague. This work describes the schedule of the ELIMED project and the design of the energy selector which will be realized at INFN-LNS. The device is an important part of the whole transport beam line which will be realised in order to make the ion beams suitable for medical applications.

  13. Final Report. Center for Scalable Application Development Software

    SciTech Connect

    Mellor-Crummey, John

    2014-10-26

    The Center for Scalable Application Development Software (CScADS) was established as a part- nership between Rice University, Argonne National Laboratory, University of California Berkeley, University of Tennessee – Knoxville, and University of Wisconsin – Madison. CScADS pursued an integrated set of activities with the aim of increasing the productivity of DOE computational scientists by catalyzing the development of systems software, libraries, compilers, and tools for leadership computing platforms. Principal Center activities were workshops to engage the research community in the challenges of leadership computing, research and development of open-source software, and work with computational scientists to help them develop codes for leadership computing platforms. This final report summarizes CScADS activities at Rice University in these areas.

  14. Direct Laser Cladding , Current Status and Future Scope of Application

    NASA Astrophysics Data System (ADS)

    Weisheit, A.; Gasser, A.; Backes, G.; Jambor, T.; Pirch, N.; Wissenbach, K.

    During the last decades Direct Laser Cladding has become an established technique in many industrial fields for applying wear and corrosion protection layers on metallic surfaces as well as for the repair of high value-added components. The most important application fields are die and tool making, turbine components for aero engines and power generation, machine components such as axes and gears, and oil drilling components. Continuous wave (CW) lasers with a power up to 18 kW are used on automated machines with three or more axes, enabling 3D cladding . The outstanding feature of DLC is the high precision which leads to a minimum heat input into the work piece and a very low distortion. Due to the high cooling rates a fine grained microstructure is achieved during solidification. A new development in laser cladding is micro cladding in a size range below 50 \\upmum especially for electronic and medical applications. Furthermore, additive manufacturing is coming again into focus as a clean and resource-efficient method to manufacture and modify functional prototypes as well as unique and small lot parts.

  15. A linewidth-narrowed and frequency-stabilized dye laser for application in laser cooling of molecules.

    PubMed

    Dai, D P; Xia, Y; Yin, Y N; Yang, X X; Fang, Y F; Li, X J; Yin, J P

    2014-11-17

    We demonstrate a robust and versatile solution for locking the continuous-wave dye laser for applications in laser cooling of molecules which need linewidth-narrowed and frequency-stabilized lasers. The dye laser is first stabilized with respect to a reference cavity by Pound-Drever-Hall (PDH) technique which results in a single frequency with the linewidth 200 kHz and short-term stabilization, by stabilizing the length of the reference cavity to a stabilized helium-neon laser we simultaneously transfer the ± 2 MHz absolute frequency stability of the helium-neon laser to the dye laser with long-term stabilization. This allows the dye laser to be frequency chirped with the maximum 60 GHz scan range while its frequency remains locked. It also offers the advantages of locking at arbitrary dye laser frequencies, having a larger locking capture range and frequency scanning range to be implemented via software. This laser has been developed for the purpose of laser cooling a molecular magnesium fluoride beam.

  16. A linewidth-narrowed and frequency-stabilized dye laser for application in laser cooling of molecules.

    PubMed

    Dai, D P; Xia, Y; Yin, Y N; Yang, X X; Fang, Y F; Li, X J; Yin, J P

    2014-11-17

    We demonstrate a robust and versatile solution for locking the continuous-wave dye laser for applications in laser cooling of molecules which need linewidth-narrowed and frequency-stabilized lasers. The dye laser is first stabilized with respect to a reference cavity by Pound-Drever-Hall (PDH) technique which results in a single frequency with the linewidth 200 kHz and short-term stabilization, by stabilizing the length of the reference cavity to a stabilized helium-neon laser we simultaneously transfer the ± 2 MHz absolute frequency stability of the helium-neon laser to the dye laser with long-term stabilization. This allows the dye laser to be frequency chirped with the maximum 60 GHz scan range while its frequency remains locked. It also offers the advantages of locking at arbitrary dye laser frequencies, having a larger locking capture range and frequency scanning range to be implemented via software. This laser has been developed for the purpose of laser cooling a molecular magnesium fluoride beam. PMID:25402105

  17. A handheld laser-induced fluorescence detector for multiple applications.

    PubMed

    Fang, Xiao-Xia; Li, Han-Yang; Fang, Pan; Pan, Jian-Zhang; Fang, Qun

    2016-04-01

    In this paper, we present a compact handheld laser-induced fluorescence (LIF) detector based on a 450 nm laser diode and quasi-confocal optical configuration with a total size of 9.1 × 6.2 × 4.1 cm(3). Since there are few reports on the use of 450 nm laser diode in LIF detection, especially in miniaturized LIF detector, we systematically investigated various optical arrangements suitable for the requirements of 450 nm laser diode and system miniaturization, including focusing lens, filter combination, and pinhole, as well as Raman effect of water at 450 nm excitation wavelength. As the result, the handheld LIF detector integrates the light source (450 nm laser diode), optical circuit module (including a 450 nm band-pass filter, a dichroic mirror, a collimating lens, a 525 nm band-pass filter, and a 1.0mm aperture), optical detector (miniaturized photomultiplier tube), as well as electronic module (including signal recording, processing and displaying units). This detector is capable of working independently with a cost of ca. $2000 for the whole instrument. The detection limit of the instrument for sodium fluorescein solution is 0.42 nM (S/N=3). The broad applicability of the present system was demonstrated in capillary electrophoresis separation of fluorescein isothiocyanate (FITC) labeled amino acids and in flow cytometry of tumor cells as an on-line LIF detector, as well as in droplet array chip analysis as a LIF scanner. We expect such a compact LIF detector could be applied in flow analysis systems as an on-line detector, and in field analysis and biosensor analysis as a portable universal LIF detector. PMID:26838391

  18. Application of Doppler and transit laser anemometry in small turbomachines

    NASA Astrophysics Data System (ADS)

    Elder, R. L.; Forster, C. P.; Gill, M. E.

    1986-11-01

    The selection laser anemometry systems and their application to the particularly hostile environment found in small high speed rotating turbomachines are discussed. There are several different laser anemometry systems which are used in turbomachinery studies and when selecting a system to carry out specific duties it is necessary to have some prior knowledge of the flows to be measured, the spacial resolution required and any limitations on optical access. The optical access will often determine the spatial resolution possible and the quality of the scattered signal will generally determine the type of signal processor which can be used. The criteria used for the selection of systems at Cranfield are discussed. The arrangements in use include both the Doppler and transit systems each of which are found to have unique and very distinct advantages.

  19. High-brightness, fiber-coupled pump modules in fiber laser applications

    NASA Astrophysics Data System (ADS)

    Hemenway, Marty; Urbanek, Wolfram; Hoener, Kylan; Kennedy, Keith W.; Bao, Ling; Dawson, David; Cragerud, Emily S.; Balsley, David; Burkholder, Gary; Reynolds, Mitch; Price, Kirk; Haden, Jim; Kanskar, Manoj; Kliner, Dahv A.

    2014-03-01

    High-power, high-brightness, fiber-coupled pump modules enable high-performance industrial fiber lasers with simple system architectures, multi-kW output powers, excellent beam quality, unsurpassed reliability, and low initial and operating costs. We report commercially available (element™), single-emitter-based, 9xx nm pump sources with powers up to 130 W in a 105 μm fiber and 250 W in a 200 μm fiber. This combination of high power and high brightness translates into improved fiber laser performance, e.g., simultaneously achieving high nonlinear thresholds and excellent beam quality at kW power levels. Wavelength-stabilized, 976 nm versions of these pumps are available for applications requiring minimization of the gain-fiber length (e.g., generation of high-peak-power pulses). Recent prototypes have achieved output powers up to 300 W in a 200 μm fiber. Extensive environmental and life testing at both the chip and module level under accelerated and real-world operating conditions have demonstrated extremely high reliability, with innovative designs having eliminated package-induced-failure mechanisms. Finally, we report integrated Pump Modules that provide < 1.6 kW of fiber-coupled power conveniently formatted for fiber-laser pumping or direct-diode applications; these 19" rack-mountable, 2U units combine the outputs of up to 14 elements™ using fused-fiber combiners, and they include high-efficiency diode drivers and safety sensors.

  20. First application of laser welding in clinical transplantation of the cornea

    NASA Astrophysics Data System (ADS)

    Pini, Roberto; Menabuoni, Luca; Starnotti, Lorenzo

    2001-05-01

    After a 4-year-long pre-clinical experimentation carried out at first on enucleated eyes and then on animal models, we applied a new procedure of laser welding of the cornea on voluntary patients. The welding technique is based on controlled irradiation of the cornea by diode laser radiation (805 nm) operating at low power (60-90 mW) in association with a photoenhancing chromophore applied locally. The welding effect is very effective and selective, because it takes place only in the cut where chromophore is present, while the contiguous tissue remains completely untouched. In the clinical phase, this technique was firstly tested in corneal cuts of increasing length on 25 patients subjected to facoemulsification of the cataract, by both sclero-corneal and corneal tunnels, and to extracapsular cataract extraction by sclero-corneal and corneal cuts. As previously confirmed by histological analysis performed on animal samples, we observed in humans too an early and effective healing process, with a sensible reduction of the post-operatory astigmatism. Based on these positive results, we finally arrived at the first application of diode laser- assisted corneal welding to penetrating keratoplasty (corneal transplantation), where this technique has been employed as far as now in 3 cases to substitute the application of the continuous suture.

  1. Laser-activated remote phosphor light engine for projection applications

    NASA Astrophysics Data System (ADS)

    Daniels, Martin; Mehl, Oliver; Hartwig, Ulrich

    2015-09-01

    Recent developments in blue emitting laser diodes enable attractive solutions in projection applications using phosphors for efficient light conversion with very high luminance levels. Various commercially available projectors incorporating this technology have entered the market in the past years. While luminous flux levels are still comparable to lamp-based systems, lifetime expectations of classical lamp systems are exceeded by far. OSRAM GmbH has been exploring this technology for several years and has introduced the PHASER® brand name (Phosphor + laser). State-of-the-art is a rotating phosphor wheel excited by blue laser diodes to deliver the necessary primary colors, either sequentially for single-imager projection engines, or simultaneously for 3-panel systems. The PHASER® technology enables flux and luminance scaling, which allows for smaller imagers and therefore cost-efficient projection solutions. The resulting overall efficiency and ANSI lumen specification at the projection screen of these systems is significantly determined by the target color gamut and the light transmission efficiency of the projection system. With increasing power and flux level demand, thermal issues, especially phosphor conversion related, dominate the opto-mechanical system design requirements. These flux levels are a great challenge for all components of an SSL-projection system (SSL:solid-state lighting). OSRAḾs PHASER® light engine platform is constantly expanded towards higher luminous flux levels as well as higher luminance levels for various applications. Recent experiments employ blue laser pump powers of multiple 100 Watts to excite various phosphors resulting in luminous flux levels of more than 40 klm.

  2. [Laser Raman Spectroscopy and Its Application in Gas Hydrate Studies].

    PubMed

    Fu, Juan; Wu, Neng-you; Lu, Hai-long; Wu, Dai-dai; Su, Qiu-cheng

    2015-11-01

    Gas hydrates are important potential energy resources. Microstructural characterization of gas hydrate can provide information to study the mechanism of gas hydrate formation and to support the exploitation and application of gas hydrate technology. This article systemly introduces the basic principle of laser Raman spectroscopy and summarizes its application in gas hydrate studies. Based on Raman results, not only can the information about gas composition and structural type be deduced, but also the occupancies of large and small cages and even hydration number can be calculated from the relative intensities of Raman peaks. By using the in-situ analytical technology, laser Raman specstropy can be applied to characterize the formation and decomposition processes of gas hydrate at microscale, for example the enclathration and leaving of gas molecules into/from its cages, to monitor the changes in gas concentration and gas solubility during hydrate formation and decomposition, and to identify phase changes in the study system. Laser Raman in-situ analytical technology has also been used in determination of hydrate structure and understanding its changing process under the conditions of ultra high pressure. Deep-sea in-situ Raman spectrometer can be employed for the in-situ analysis of the structures of natural gas hydrate and their formation environment. Raman imaging technology can be applied to specify the characteristics of crystallization and gas distribution over hydrate surface. With the development of laser Raman technology and its combination with other instruments, it will become more powerful and play a more significant role in the microscopic study of gas hydrate. PMID:26978895

  3. Experimental and computer modeling studies of isotopically selective two-step laser photodissociation of small molecules. Final report

    SciTech Connect

    Zittel, P.F.

    1992-03-25

    The approach to laser isotope separation taken in this study is based on isotopically selective, two-step, laser photodissociation of small molecules. A primary goal of this study is the measurement of fundamental molecular processes which control the two-step, photodissociative isotope enrichment process. This objective has led to experimental measurements of uv photodissociation cross sections for vibrationally excited states of several small molecules, including the first cross section reported for any neutral molecule in a specific, excited vibrational state. A second goal of this study has been the laboratory demonstration of isotope enrichment for isotopes of practical interest and for processes with a potential for larger scale production. Where possible, efforts have focussed on the separation of middle isotopes, such as {sup 17}O and {sup 33}S, which are expensive and difficult to separate using other techniques. Considerable success has been achieved in demonstrating the enrichment of isotopes of bromine, carbon, oxygen and a third goal of this study has been the application of computer modeling to the two-step enrichment process. Experimental measurements define as many as possible of the critical photophysical and chemical parameters required by an ab initio computer model of the enrichment process. Progress toward these goals has been documented in detail in a variety of journal articles and technical reports. It is not the objective of this final report to discuss each aspect of the work done under this contract/grant in detail. A general overview of the program, touches briefly on each of the problems addressed by the study and provides references to more detailed discussions. 19 refs.

  4. Unique applications for artificial neural networks. Phase 1. Final report

    SciTech Connect

    Not Available

    1991-08-08

    The investigation concerns the application of modular neural networks, working synergistically with genetic search, to provide a powerful means of intelligently controlling heuristic mathematical algorithms for large-scale vehicle routing and scheduling problems. The design lends itself naturally to parallel computing on loosely coupled networks of computers, and to implementation on parallel architectures such as MIMD machines. Extensive developmental work, coding and computational testing was carried on generic vehicle routing problems. The results are consistently superior to known alternatives, and provide strong motivation to extend the approach into more complex problem domains and military applications. The basic approach was also applied to routing problems with time constraints, a significant complication of considerable practical importance. Results of this problem are also consistently good, and there is potential to further investigate the use of the approach in this domain. Finally, very preliminary results are available for applying the methodology to routing and mission planning for remote autonomous military vehicles, such as Tomahawk cruise missiles or other smart weapons systems. In summary, the high performance achieved suggests that the multiparadigm approaches that utilize methods from artificial intelligence in conjunction with powerful and proven methods from mathematical combinatorial optimization can build upon the strengths of each constituent, and achieve performance that none of the methods can obtain in isolation.

  5. Case studies of industrial applications of high-power diode laser in Finland

    NASA Astrophysics Data System (ADS)

    Hovikorpi, Jari; Jansson, Anssi; Salminen, Antti

    2003-06-01

    The high power diode laser is a new industrial tool. It has several advantages and disadvantages compared to the conventional industrially used CO2 and Nd:YAG laser. The most promising areas of application of diode laser have been considered to be thin sheet welding and hardening. Quite a few feasibility studies of the use of diode laser have been carried out in Finland. So far there has been some application in which diode laser is the most suitable laser. Typically, the HPDL is integrated to an industrial robot. The welding of stainless steel housing, car door lock and catalytic converters are typical examples of applications in which diode laser has technological as well as economical advantages over the conventional laser and welding techniques. The welding of these products requires good control over the heat input, short through put time and low investment. The weld cross-section of a diode laser weld is, because of conduction limited welding process, more suitable for these applications than the keyhole welding. Hardening of a large gear wheel presents also a good example of an application in which the diode laser makes it possible to economically produce structures that have not earlier been possible. Hardening requires a special form of heat delivery in order to ensure evenly hardened zone and acceptable quality. The application was performed with two high power diode lasers. The case studies of these four applications are presented and discussed in details in this paper.

  6. Final Report on NASA Portable Laser Coating Removal Systems Field Demonstrations and Testing

    NASA Technical Reports Server (NTRS)

    Rothgeb, Matthew J; McLaughlin, Russell L.

    2008-01-01

    Processes currently used throughout the National Aeronautics and Space Administration (NASA) to remove corrosion and coatings from structures, ground service equipment, small parts and flight components result in waste streams consisting of toxic chemicals, spent media blast materials, and waste water. When chemicals are used in these processes they are typically high in volatile organic compounds (VOC) and are considered hazardous air pollutants (HAP). When blast media is used, the volume of hazardous waste generated is increased significantly. Many of the coatings historically used within NASA contain toxic metals such as hexavalent chromium, and lead. These materials are highly regulated and restrictions on worker exposure continue to increase. Most recently the Occupational Safety and Health Administration (OSHA) reduced the permissible exposure limit (PEL) for hexavalent chromium (CrVI) from 52 to 5 micrograms per cubic meter of air as an 8-hour time-weighted average. Hexavalent chromium is found in numerous pretreatment and primer coatings used within the Space Shuttle Program. In response to the need to continue to protect assets within the agency and the growing concern over these new regulations, NASA is researching different ways to continue the required maintenance of both facility and flight equipment in a safe, efficient, and environmentally preferable manner. The use of laser energy to prepare surfaces for a variety of processes, such as corrosion and coating removal, weld preparation, and non destructive evaluation (NDE) is a relatively new application of the technology that has been proven to be environmentally preferable and in many cases less labor intensive than currently used removal methods. The novel process eliminates VOCs and blast media and captures the removed coatings with an integrated vacuum system. This means that the only waste generated are the coatings that are removed, resulting in an overall cleaner process. The development of a

  7. Novel MRI Applications of Laser-Polarized Noble Gases

    NASA Astrophysics Data System (ADS)

    Mair, R. W.; Walsworth, R. L.

    2002-04-01

    Gas-phase NMR has great potential as a probe for a variety of interesting physical and biomedical problems that are not amenable to study by water or similar liquid. However, NMR of gases was largely neglected due to the low signal obtained from the thermally-polarized gases with very low sample density. The advent of optical pumping techniques for enhancing the polarization of the noble gases 3He and 129Xe has bought new life to this field, especially in medical imaging where 3He lung inhalation imaging is approaching a clinical application. However, there are numerous applications in materials science that also benefit from the use of these gases. We review primarily non-medical applications of laser-polarized noble gases for both NMR imaging and spectroscopy, and highlight progress with examples from our laboratory including high-resolution imaging at mT applied field strength and velocity imaging of convective flow. Porous media microstucture has been probed with both thermal and laser-polarized xenon, as xenon is an ideal probe due to low surface interaction with the grains of the porous media.

  8. Simple laser vision sensor calibration for surface profiling applications

    NASA Astrophysics Data System (ADS)

    Abu-Nabah, Bassam A.; ElSoussi, Adnane O.; Al Alami, Abed ElRahman K.

    2016-09-01

    Due to the relatively large structures in the Oil and Gas industry, original equipment manufacturers (OEMs) have been implementing custom-designed laser vision sensor (LVS) surface profiling systems as part of quality control in their manufacturing processes. The rough manufacturing environment and the continuous movement and misalignment of these custom-designed tools adversely affect the accuracy of laser-based vision surface profiling applications. Accordingly, Oil and Gas businesses have been raising the demand from the OEMs to implement practical and robust LVS calibration techniques prior to running any visual inspections. This effort introduces an LVS calibration technique representing a simplified version of two known calibration techniques, which are commonly implemented to obtain a calibrated LVS system for surface profiling applications. Both calibration techniques are implemented virtually and experimentally to scan simulated and three-dimensional (3D) printed features of known profiles, respectively. Scanned data is transformed from the camera frame to points in the world coordinate system and compared with the input profiles to validate the introduced calibration technique capability against the more complex approach and preliminarily assess the measurement technique for weld profiling applications. Moreover, the sensitivity to stand-off distances is analyzed to illustrate the practicality of the presented technique.

  9. Materials Development and Evaluation of Selective Laser Sintering Manufacturing Applications

    SciTech Connect

    Smith, Peter F.; Mitchell, Russell R.

    1997-01-15

    This report summarizes the FY96 accomplishments for CRADA No. LA95C10254, "Materials Development and Evaluation of Laser Sintering Manufacturing Applications". To research the potential for processing additional materials using DTM Corporations Selective Laser Sintering rapid prototyping technology and evaluate the capability for rapid manufacturing applications, the following materials were processed experimentally using the Sinterstation 2000 platform; Linear Low Density Polyethylene thermoplastic; Polypropylene thermoplastic; Polysulfone thermoplastic; Polymethylpentene (TPX) thermoplastic; Carbon microsphere filled nylon 11; "APO-BMI" Apocure bismaleimide thermoset polyimide glass m.icrosphere filled and carbon microsphere filled formulations; and 900-24 physical properties mock for plastic bonded TATB high explosive These materials have been successfully processed to a "proof of concept" level or better (with the exception of No. 7). While none of these materials have been introduced as a standard product as of this date, the potential to do so is viable. Present status of materials processing efforts is presented in Section A 2.0. Some recent efforts in manufacturing applications is discussed in Section A 4.0.

  10. Medical research and multidisciplinary applications with laser-accelerated beams: the ELIMED netwotk at ELI-Beamlines

    NASA Astrophysics Data System (ADS)

    Tramontana, A.; Anzalone, A.; Candiano, G.; Carpinelli, M.; Cirrone, G. A. P.; Cuttone, G.; Korn, G.; Licciardello, T.; Maggiore, M.; Manti, L.; Margarone, D.; Musumarra, A.; Perozziello, F.; Pisciotta, P.; Raffaele, L.; Romano, F.; Romano, F. P.; Stancampiano, C.; Schillaci, F.; Scuderi, V.; Torrisi, L.; Tudisco, S.

    2014-04-01

    Laser accelerated proton beams represent nowadays an attractive alternative to the conventional ones and they have been proposed in different research fields. In particular, the interest has been focused in the possibility of replacing conventional accelerating machines with laser-based accelerators in order to develop a new concept of hadrontherapy facilities, which could result more compact and less expensive. With this background the ELIMED (ELIMED: ELI-Beamlines MEDical applications) research project has been launched by LNS-INFN researchers (Laboratori Nazionali del Sud-Istituto Nazionale di Fisica Nucleare, Catania, IT) and ASCR-FZU researchers (Academy of Sciences of the Czech Republic-Fyzikální ústar, Prague, Cz), within the pan-European ELI-Beamlines facility framework. Its main purposes are the demonstration of future applications in hadrontherapy of optically accelerated protons and the realization of a laser-accelerated ion transport beamline for multidisciplinary applications. Several challenges, starting from laser-target interaction and beam transport development, up to dosimetric and radiobiological issues, need to be overcome in order to reach the final goals. The design and the realization of a preliminary beam handling and dosimetric system and of an advanced spectrometer for high energy (multi-MeV) laser-accelerated ion beams will be shortly presented in this work.

  11. Application of laser velocimetry to aircraft wake-vortex measurements

    NASA Technical Reports Server (NTRS)

    Ciffone, D. L.; Orloff, K. L.

    1977-01-01

    The theory and use of a laser velocimeter that makes simultaneous measurements of vertical and longitudinal velocities while rapidly scanning a flow field laterally are described, and its direct application to trailing wake-vortex research is discussed. Pertinent measurements of aircraft wake-vortex velocity distributions obtained in a wind tunnel and water towing tank are presented. The utility of the velocimeter to quantitatively assess differences in wake velocity distributions due to wake dissipating devices and span loading changes on the wake-generating model is also demonstrated.

  12. News applications in authentication and traceability using ultrafast laser marking

    NASA Astrophysics Data System (ADS)

    Dusser, B.; Sagan, Z.; Foucou, A.; Jourlin, M.; Audouard, E.

    2009-02-01

    This work presents a new method for ultra-fast laser marking using nano-structures as well as a suitable method of reading. These nano-structures, called ripples, are an irregular grating with a controllable orientation. It is possible to observe these ripples and theirs orientations with differents acquisitions systems. The one we chose to use is a scanner. It is possible to have an ripples' orientation matching one of the colors in the image acquisition. This feature allows us to consider new applications for marking and new types of identifying code.

  13. Center of Excellence for Laser Applications in Medicine, Microlaser Microscope

    SciTech Connect

    Webb, R. H.

    2003-01-17

    The Center of Excellence for Laser Applications in Medicine at the Schepens Eye Research Institute (SERI) is a Center for: A core group of researchers who support each other and their various projects for real-time medical imaging and diagnostics in contiguous space at SERI. Clinical collaborators who participate in the core research at SERI, MEEI, and local ophthalmology practices, and at associated sites around the world. Industrial partners who transfer our technology to commercial products that will reach clinical usage everywhere. Students, post-doctoral associates and medical fellows who work with us and learn how to practice real-time medical imaging and diagnostics.

  14. External cavity quantum cascade lasers for spectroscopic applications

    NASA Astrophysics Data System (ADS)

    Tsai, Tracy

    Mid-infrared spectroscopy is a powerful tool in monitoring trace gases for applications in atmospheric science, industrial processes, and homeland security. However, although current mid-infrared spectrometers (i.e. Fourier Transform Spectrometers or FTS) have a wide spectral range for multi-species and/or broadband molecular detection, they are too large with slow scan rates for practical use in high resolution spectroscopic applications. Quantum cascade lasers (QCLs) are compact, powerful, and efficient mid-infrared sources that can be quantum engineered with broadband gain profiles. Placed inside a diffraction grating based external cavity arrangement, they can easily provide >100 cm -1 frequency range with a spectral resolution limited by the laser linewidth (˜10-3 cm-1). Therefore, the external cavity quantum cascade laser (EC-QCL) provides both high spectral resolution and a wide frequency range. This thesis describes the study and development of EC-QCLs for spectroscopic applications. A new active wavelength method is presented to simplify the spectrometer system by allowing for reliable operation of the EC-QCL without additional wavelength diagnostic equipment. Typically, such equipment must be added to the spectrometer, because the grating equation is inaccurate in describing the EC-QCL output wavelength due to spectral misalignment of other wavelength-selective resonances in the EC-QCL. The active wavelength locking method automatically controls the EC-QCL wavelength, which improves the accuracy of the grating equation to 0.06 cm-1 and offers an ultimate 3σ precision of 0.042 cm-1. For industrial spectroscopic sensing applications in which scan rates must be on the order of kilohertz so that the turbulent gas system can be approximated as a quasi-stable one, a fast-wavelength-scanning folded EC-QCL design capable of 1 kHz scan rate is presented. Two modes of operation have been studied: 1) low resolution pulsed mode and 2) high resolution continuous

  15. Ultrafast laser inscribed fiber Bragg gratings for sensing applications

    NASA Astrophysics Data System (ADS)

    Mihailov, Stephen J.

    2016-05-01

    Because of their small size, passive nature, immunity to electromagnetic interference, and capability to directly measure physical parameters such as temperature and strain, fiber Bragg grating sensors have developed beyond a laboratory curiosity and are becoming a mainstream sensing technology. Recently, high temperature stable gratings based on femtosecond infrared laser-material processing have shown promise for use in extreme environments such as high temperature, pressure or ionizing radiation. Such gratings are ideally suited for energy production applications where there is a requirement for advanced energy system instrumentation and controls that are operable in harsh environments. This tutorial paper will present a review of some of the more recent developments.

  16. Laser applications present and future: Prospects for significant occupational safety and health impact

    NASA Astrophysics Data System (ADS)

    Smith, J. P.

    1982-06-01

    Applications of lasers are growing in a number of areas; some applications are relatively widespread with developed industrial laser processes while others are considered purely research and development applications with little industrial use at the present time. In this brief writeup an attempt will be made to examine present and future areas of laser use and assess how they may impact on occupational safety and health in either a positive or negative way.

  17. Robust remote-pumping sodium laser for advanced LIDAR and guide star applications

    NASA Astrophysics Data System (ADS)

    Ernstberger, Bernhard; Enderlein, Martin; Friedenauer, Axel; Schwerdt, Robin; Wei, Daoping; Karpov, Vladimir; Leisching, Patrick; Clements, Wallace R. L.; Kaenders, Wilhelm G.

    2015-10-01

    The performance of large ground-based optical telescopes is limited due to wavefront distortions induced by atmospheric turbulence. Adaptive optics systems using natural guide stars with sufficient brightness provide a practical way for correcting the wavefront errors by means of deformable mirrors. Unfortunately, the sky coverage of bright stars is poor and therefore the concept of laser guide stars was invented, creating an artificial star by exciting resonance fluorescence from the mesospheric sodium layer about 90 km above the earth's surface. Until now, mainly dye lasers or sumfrequency mixing of solid state lasers were used to generate laser guide stars. However, these kinds of lasers require a stationary laser clean room for operation and are extremely demanding in maintenance. Under a development contract with the European Southern Observatory (ESO) and W. M. Keck Observatory (WMKO), TOPTICA Photonics AG and its partner MPB Communications have finalized the development of a next-generation sodium guide star laser system which is available now as a commercial off-the-shelf product. The laser is based on a narrow-band diode laser, Raman fiber amplifier (RFA) technology and resonant second-harmonic generation (SHG), thus highly reliable and simple to operate and maintain. It emits > 22 W of narrow-linewidth (≈ 5 MHz) continuous-wave radiation at sodium resonance and includes a re-pumping scheme for boosting sodium return flux. Due to the SHG resonator acting as spatial mode filter and polarizer, the output is diffraction-limited with RMS wavefront error < λ/25. Apart from this unique optical design, a major effort has been dedicated to integrating all optical components into a ruggedized system, providing a maximum of convenience and reliability for telescope operators. The new remote-pumping architecture allows for a large spatial separation between the main part of the laser and the compact laser head. Together with a cooling-water flow of less than 5 l

  18. A versatile interaction chamber for laser-based spectroscopic applications, with the emphasis on Laser-Induced Breakdown Spectroscopy

    NASA Astrophysics Data System (ADS)

    Novotný, J.; Brada, M.; Petrilak, M.; Prochazka, D.; Novotný, K.; Hrdička, A.; Kaiser, J.

    2014-11-01

    The technical note describes the interaction chamber developed particularly for the laser spectroscopy technique applications, such as Laser-Induced Breakdown Spectroscopy (LIBS), Raman Spectroscopy and Laser-Induced Fluorescence. The chamber was designed in order to provide advanced possibilities for the research in mentioned fields and to facilitate routine research procedures. Parameters and the main benefits of the chamber are described, such as the built-in module for automatic 2D chemical mapping and the possibility to set different ambient gas conditions (pressure value and gas type). Together with the chamber description, selected LIBS application examples benefiting from chamber properties are described.

  19. Gas and metal vapor lasers and applications; Proceedings of the Meeting, Los Angeles, CA, Jan. 22, 23, 1991

    NASA Astrophysics Data System (ADS)

    Kim, Jin J.; Tittel, Frank K.

    Various papers on gas and metal vapor lasers and applications are presented. Individual topics addressed include: high-power copper vapor laser development, modified off-axis unstable resonator for copper vapor laser, industrial applications of metal vapor lasers, newly developed excitation circuit for kHz pulsed lasers, copper vapor laser precision processing, development of solid state pulse power supply for copper vapor laser, multiple spectral structure of the 578.2-nm line for copper vapor laser, adsorption of bromine in CuBr laser, processing of polytetrafluoroethylene with high-power VUV laser radiation, characterization of a subpicosecond XeF(C - A) excimer laser, X-ray preionization for high-repetition-rate discharge excimer lasers. Also discussed are: investigation of microwave-pumped excimer and rare-gas laser transitions, influence of gas composition of XeCl laser performance, output power stabilization of a XeCl excimer laser by HCl gas injection, excimer laser machining of optical fiber taps, diagnostics of a compact UV-preionized XeCl laser with BCl3 halogen donor, blackbody-pumped CO32 lasers using Gaussian and waveguide cavities, chemical problems of high-power sealed-off CO lasers, laser action of Xe and Ne pumped by electron beam, process monitoring during CO2 laser cutting, double-pulsed TEA CO2 laser, superhigh-gain gas laser, high-power ns-pulse iodine laser provided with SBS mirror. (No individual items are abstracted in this volume)

  20. Laser ultrasonic probe for industrial or high-temperature applications

    NASA Astrophysics Data System (ADS)

    Hopko, Sandra Nowland

    1998-12-01

    Ultrasonic nondestructive testing is typically used for location and sizing of internal and surface defects or for measuring material properties. Traditional techniques use contacting transducers, which are difficult to implement for on-line quality control or high temperature applications. Because laser ultrasonic (LU) systems are non-contacting, they can be used for testing moving specimens or for operation in hazardous environments. One of the most promising applications for LU inspection systems is high temperature testing. Fundamental LU research was performed to investigate the effects of specimen temperature on the generation and propagation of ultrasound. Results include ambient and elevated temperature measurements of on-epicenter sound pressures and directivity patterns. Numerical modeling for refraction through a temperature gradient is also included. In order to enhance bulk wave generation, a phased array was designed and constructed using optical fiber bundles. Because the fibers are fragile, a fiber containment ring was developed. The phased array can be used with a focusing objective to obtain a variety of beam steering angles. Depending on the application, the system can be calibrated to use either thermoelastic or ablative sources. This work includes the first implementation of an ablative phased array. Results include theoretical analysis of ablative phased arrays and experimentally obtained directivity patterns for thermoelastic, transition and ablation sources. LU inspection systems using optical fiber delivery are highly versatile. Introduction of a distal-end, focusing objective into the optical fiber delivery system increases the allowable working distance between the optical fiber(s) and test specimen. The focusing objective permits strong generation, using material ablation as the generating mechanism. This work includes the design and testing of two focusing objectives. Results include experimentally obtained directivity patterns

  1. Diode-Pumped Alkali Atom Lasers 03-LW-024 Final Report

    SciTech Connect

    Page, R H; Beach, R J

    2005-02-16

    The recent work at LLNL on alkali-atom lasers has been remarkably successful and productive. Three main phases (so far) can be identified. First, the concept and demonstration of red lasers using (Ti:sapphire pumping) took place; during this time, Rubidium and Cesium resonance-line lasers were tested, and theoretical models were developed and shown to describe experimental results very reliably. Work done during this first phase has been well documented, and the models from that period are still in use for their predictions and for designing power-scaled lasers. [1 - 3] Second, attempts were made to produce a blue alkali-vapor laser using sequentially-resonant two-step pumping (again, using Ti:sapphire lasers.) Although a blue laser did not result, the physical limitations of our approach are now better-defined. Third, diode-pumped operation of a red laser (Rubidium) was attempted, and we eventually succeeded in demonstrating the world's first diode-pumped gas laser. [4] Because we have a defensible concept for producing an efficient, compact, lightweight, power-scaled laser (tens of kW,) we are in a position to secure outside funding, and would like to find a sponsor. For descriptions of work done during the ''first phase,'' see References [1 - 3] ''Phase two'' work is briefly described in the section ''Blue laser,'' and ''phase three'' work is presented in the section entitled ''Diode-pumped red laser.''

  2. Qualification and Selection of Flight Diode Lasers for Space Applications

    NASA Technical Reports Server (NTRS)

    Liebe, Carl C.; Dillon, Robert P.; Gontijo, Ivair; Forouhar, Siamak; Shapiro, Andrew A.; Cooper, Mark S.; Meras, Patrick L.

    2010-01-01

    The reliability and lifetime of laser diodes is critical to space missions. The Nuclear Spectroscopic Telescope Array (NuSTAR) mission includes a metrology system that is based upon laser diodes. An operational test facility has been developed to qualify and select, by mission standards, laser diodes that will survive the intended space environment and mission lifetime. The facility is situated in an electrostatic discharge (ESD) certified clean-room and consist of an enclosed temperature-controlled stage that can accommodate up to 20 laser diodes. The facility is designed to characterize a single laser diode, in addition to conducting laser lifetime testing on up to 20 laser diodes simultaneously. A standard laser current driver is used to drive a single laser diode. Laser diode current, voltage, power, and wavelength are measured for each laser diode, and a method of selecting the most adequate laser diodes for space deployment is implemented. The method consists of creating histograms of laser threshold currents, powers at a designated current, and wavelengths at designated power. From these histograms, the laser diodes that illustrate a performance that is outside the normal are rejected and the remaining lasers are considered spaceborne candidates. To perform laser lifetime testing, the facility is equipped with 20 custom laser drivers that were designed and built by California Institute of Technology specifically to drive NuSTAR metrology lasers. The laser drivers can be operated in constant-current mode or alternating-current mode. Situated inside the enclosure, in front of the laser diodes, are 20 power-meter heads to record laser power throughout the duration of lifetime testing. Prior to connecting a laser diode to the current source for characterization and lifetime testing, a background program is initiated to collect current, voltage, and resistance. This backstage data collection enables the operational test facility to have full laser diode

  3. Single frequency and wavelength stabilized near infrared laser source for water vapor DIAL remote sensing application

    NASA Astrophysics Data System (ADS)

    Chuang, Ti; Walters, Brooke; Shuman, Tim; Losee, Andrew; Schum, Tom; Puffenberger, Kent; Burnham, Ralph

    2015-02-01

    Fibertek has demonstrated a single frequency, wavelength stabilized near infrared laser transmitter for NASA airborne water vapor DIAL application. The application required a single-frequency laser transmitter operating at 935 nm near infrared (NIR) region of the water vapor absorption spectrum, capable of being wavelength seeded and locked to a reference laser source and being tuned at least 100 pm across the water absorption spectrum for DIAL on/off measurements. Fibertek is building a laser transmitter system based on the demonstrated results. The laser system will be deployed in a high altitude aircraft (ER-2 or UAV) to autonomously perform remote, long duration and high altitude water vapor measurements.

  4. Applications of laser lithography on oxide film to titanium micromachining

    NASA Astrophysics Data System (ADS)

    Chauvy, P.-F.; Hoffmann, P.; Landolt, D.

    2003-03-01

    Due to its good biocompatibility titanium is widely used for dental and orthopaedics implants and for biomedical microsystems. For these applications one needs specific micromachining methods. A new four-step method for electrochemical micromachining of titanium is presented here, which implies anodic oxidation, Excimer laser sensitising irradiation, anodic dissolution, and ultrasonic cleaning. The method is applied to the fabrication of two 3D model structures, surface structuring of a cylinder and machining of a complex two-level architecture. The absence of debris and of a heat affected zone as well as the resulting surface smoothness are the main advantages of the process. Ways to improve the still limited processing speed are discussed with regards to potential applications.

  5. Compact laser vibrometer for industrial and medical applications

    NASA Astrophysics Data System (ADS)

    Lewin, Andrew C.

    1998-06-01

    Laser interferometric vibrometers are now well known and accepted as sensitive, accurate, high bandwidth and linear measurement system. For many applications the internal complexity and resultant size of the interferometric sensor head limits the widespread use. This paper describes the performance and principle of operation of a new miniaturized interferometric sensor head which retains the important characteristics of the previously mentioned systems, but embodied in a robust compact housing no larger thana typical torchlight. Velocity resolution in the acoustic range has been found to be up to 50 nanometers/sec in a 10 Hz RBW. The size of this new sensor head allows it to be mounted on balanced microscope assemblies or within machinery, and the waterproof design allows disinfectant cleaning in clinical applications or operation in industrial environments.

  6. Laser reconditioning of crankshafts: From lab to application

    NASA Astrophysics Data System (ADS)

    Koehler, H.; Partes, K.; Seefeld, T.; Vollertsen, F.

    In marine diesel engines, damaged crankshafts are common and expensive defects. Worn surfaces of main bearings and crankpin journals often require a complete replacement of these components. This paper presents the development of a repair procedure on its way to application. As an alternative to the method of grinding the accordant surfaces and using matched bearing shells, a rebuild to the original diameter is the goal of this investigation. This paper describes the development of a controlled diode laser cladding process in the lab and the characterization of flat specimens particularly by metallographic analysis and hardness testing. In preparation of the industrial application, previously ground crankpin journals of crankshafts could successfully be cladded with identical parameters as found on flat specimens in the lab. The claddings show a high quality in terms of connection to the base material and dilution. In hardness tests steep gradients from heat affected zone to unaffected base material could be measured.

  7. Applications of a single-longitudinal-mode alexandrite laser for diagnostics of parameters of combustion interest

    NASA Astrophysics Data System (ADS)

    Li, Z. S.; Afzelius, M.; Zetterberg, J.; Aldén, M.

    2004-10-01

    We report on the applications of a single-longitudinal-mode (SLM) pulsed alexandrite laser system for diagnostics of parameters of flow/combustion interest. The laser system is characterized by its narrow linewidth, high peak power, and broad tunablity. The absolute frequency of the laser output was monitored by a wavelength diagnostic system, which included a high-resolution confocal etalon and a molecular iodine laser-induced fluorescence (LIF) detection system. Different nonlinear frequency conversion schemes were used to cover a large frequency range from the infrared to the deep UV. The versatility of the laser system for flow/combustion diagnostics is demonstrated in three applications, namely filtered Rayleigh scattering, high-resolution Doppler-free two-photon LIF of CO, and infrared LIF and polarization spectroscopy of CO2. The potential impacts of using this SLM laser system in laser flow/combustion diagnostic applications are discussed.

  8. Development of ytterbium-doped oxyfluoride glasses for laser cooling applications

    PubMed Central

    Krishnaiah, Kummara Venkata; Soares de Lima Filho, Elton; Ledemi, Yannick; Nemova, Galina; Messaddeq, Younes; Kashyap, Raman

    2016-01-01

    Oxyfluoride glasses doped with 2, 5, 8, 12, 16 and 20 mol% of ytterbium (Yb3+) ions have been prepared by the conventional melt-quenching technique. Their optical, thermal and thermo-mechanical properties were characterized. Luminescence intensity at 1020 nm under laser excitation at 920 nm decreases with increasing Yb3+ concentration, suggesting a decrease in the photoluminescence quantum yield (PLQY). The PLQY of the samples was measured with an integrating sphere using an absolute method. The highest PLQY was found to be 0.99(11) for the 2 mol% Yb3+: glass and decreases with increasing Yb3+ concentration. The mean fluorescence wavelength and background absorption of the samples were also evaluated. Upconversion luminescence under 975 nm laser excitation was observed and attributed to the presence of Tm3+ and Er3+ ions which exist as impurity traces with YbF3 starting powder. Decay curves for the Yb3+: 2F5/2 → 2F7/2 transition exhibit single exponential behavior for all the samples, although lifetime decrease was observed for the excited level of Yb3+ with increasing Yb3+ concentration. Also observed are an increase in the PLQY and a slight decrease in lifetime with increasing the pump power. Finally, the potential of these oxyfluoride glasses with high PLQY and low background absorption for laser cooling applications is discussed. PMID:26915817

  9. Laser microdissection and its application to analyze gene expression in arbuscular mycorrhizal symbiosis.

    PubMed

    Gomez, S Karen; Harrison, Maria J

    2009-05-01

    Phosphorus is essential for plant growth, and in many soils phosphorus availability limits crop production. Most plants in natural ecosystems obtain phosphorus via a symbiotic partnership with arbuscular mycorrhizal (AM) fungi. While the significance of these associations is apparent, their molecular basis is poorly understood. Consequently, the potential to harness the mycorrhizal symbiosis to improve phosphorus nutrition in agriculture is not realized. Transcript profiling has recently been used to investigate gene expression changes that accompany development of the AM symbiosis. While these approaches have enabled the identification of AM-symbiosis-associated genes, they have generally involved the use of RNA from whole mycorrhizal roots. Laser microdissection techniques allow the dissection and capture of individual cells from a tissue. RNA can then be isolated from these samples and cell-type specific gene expression information can be obtained. This technology has been applied to obtain cells from plants and more recently to study plant-microbe interactions. The latter techniques, particularly those developed for root-microbe interactions, are of relevance to plant-parasitic weed research. Here, laser microdissection, its use in plant biology and in particular plant-microbe interactions are discussed. An overview of the AM symbiosis is then provided, with a focus on recent advances in understanding development of the arbuscule-cortical cell interface. Finally, the recent applications of laser microdissection for analyses of AM symbiosis are discussed.

  10. Development of ytterbium-doped oxyfluoride glasses for laser cooling applications.

    PubMed

    Krishnaiah, Kummara Venkata; de Lima Filho, Elton Soares; Ledemi, Yannick; Nemova, Galina; Messaddeq, Younes; Kashyap, Raman

    2016-01-01

    Oxyfluoride glasses doped with 2, 5, 8, 12, 16 and 20 mol% of ytterbium (Yb(3+)) ions have been prepared by the conventional melt-quenching technique. Their optical, thermal and thermo-mechanical properties were characterized. Luminescence intensity at 1020 nm under laser excitation at 920 nm decreases with increasing Yb(3+) concentration, suggesting a decrease in the photoluminescence quantum yield (PLQY). The PLQY of the samples was measured with an integrating sphere using an absolute method. The highest PLQY was found to be 0.99(11) for the 2 mol% Yb(3+): glass and decreases with increasing Yb(3+) concentration. The mean fluorescence wavelength and background absorption of the samples were also evaluated. Upconversion luminescence under 975 nm laser excitation was observed and attributed to the presence of Tm(3+) and Er(3+) ions which exist as impurity traces with YbF3 starting powder. Decay curves for the Yb(3+): (2)F5/2 → (2)F7/2 transition exhibit single exponential behavior for all the samples, although lifetime decrease was observed for the excited level of Yb(3+) with increasing Yb(3+) concentration. Also observed are an increase in the PLQY and a slight decrease in lifetime with increasing the pump power. Finally, the potential of these oxyfluoride glasses with high PLQY and low background absorption for laser cooling applications is discussed. PMID:26915817

  11. Simulation of Laser Cooling and Trapping in Engineering Applications

    NASA Technical Reports Server (NTRS)

    Ramirez-Serrano, Jaime; Kohel, James; Thompson, Robert; Yu, Nan; Lunblad, Nathan

    2005-01-01

    An advanced computer code is undergoing development for numerically simulating laser cooling and trapping of large numbers of atoms. The code is expected to be useful in practical engineering applications and to contribute to understanding of the roles that light, atomic collisions, background pressure, and numbers of particles play in experiments using laser-cooled and -trapped atoms. The code is based on semiclassical theories of the forces exerted on atoms by magnetic and optical fields. Whereas computer codes developed previously for the same purpose account for only a few physical mechanisms, this code incorporates many more physical mechanisms (including atomic collisions, sub-Doppler cooling mechanisms, Stark and Zeeman energy shifts, gravitation, and evanescent-wave phenomena) that affect laser-matter interactions and the cooling of atoms to submillikelvin temperatures. Moreover, whereas the prior codes can simulate the interactions of at most a few atoms with a resonant light field, the number of atoms that can be included in a simulation by the present code is limited only by computer memory. Hence, the present code represents more nearly completely the complex physics involved when using laser-cooled and -trapped atoms in engineering applications. Another advantage that the code incorporates is the possibility to analyze the interaction between cold atoms of different atomic number. Some properties that cold atoms of different atomic species have, like cross sections and the particular excited states they can occupy when interacting with each other and light fields, play important roles not yet completely understood in the new experiments that are under way in laboratories worldwide to form ultracold molecules. Other research efforts use cold atoms as holders of quantum information, and more recent developments in cavity quantum electrodynamics also use ultracold atoms to explore and expand new information-technology ideas. These experiments give a hint

  12. Final Report on Portable Laser Coating Removal Systems Field Demonstrations and Testing

    NASA Technical Reports Server (NTRS)

    Rothgeb, Matthew J.; McLaughlin, Russell L.

    2008-01-01

    to evaluate the best performers on processes and coatings specific to the agency. Laser systems used during this project were all of a similar design, most of which had integrated vacuum systems in order to collect materials removed from substrate surfaces during operation. Due to the fact that the technology lends itself to a bide variety of processes, several site demonstrations were organized in order to allow for greater evaluation of the laser systems across NASA. The project consisted of an introductory demonstration and a more in-depth evaluation at Wright-Patterson Air Force Base. Additionally, field demonstrations occurred at Glenn Research Center and Kennedy Space Center. During these demonstrations several NASA specific applications were evaluated, including the removal of coatings within Orbiter tile cavities and Teflon from Space Shuttle Main Engine gaskets, removal of heavy grease from Solid Rocket Booster components and the removal of coatings on weld lines for Shuttle and general ground service equipment for non destructive evaluation (NDE). In addition, several general industry applications such as corrosion removal, structural coating removal, weld-line preparation and surface cleaning were evaluated. This included removal of coatings and corrosion from surfaces containing lead-based coatings and applications similar to launch-structure maintenance and Crawler maintenance. During the project lifecycle, an attempt was made to answer process specific concerns and questions as they arose. Some of these initially unexpected questions concerned the effects lasers might have on substrates used on flight equipment including strength, surface re-melting, substrate temperature and corrosion resistance effects. Additionally a concern was PPE required for operating such a system including eye, breathing and hearing protection. Most of these questions although not initially planned, were fully explored as a part of this project. Generally the results from tesng

  13. Laser noise measurement techniques and applications of femtosecond encoding in the frequency domain

    NASA Astrophysics Data System (ADS)

    Scott, Ryan Patrick

    This dissertation investigates mode-locked laser noise measurement techniques, the concept and measurement of a laser's noise transfer function, and then two applications of spectral encoding of optical pulses. The one application is optical code division multiple access (O-CDMA) and the other is optical arbitrary waveform generation (OAWG). The relationship between source stability, encoding, and overall system performance in O-CDMA is also discussed. Techniques for making sensitive and high-dynamic-range measurements of laser amplitude and envelope phase noise (timing jitter) in the frequency domain at the shot-noise limit are described. The short term stability of a Kerr-lens modelocked (KLM) Ti:sapphire laser is shown to be close to that of the precision crystal oscillators used in its characterization. The amplitude and envelope phase noise of a KLM Ti:sapphire laser are shown to depend directly on the pump laser amplitude stability. The sensitivity of this process is described by a noise transfer function (NTF) which represents the magnitude of the amplitude-to-amplitude modulation and amplitude-to-phase modulation conversion gain of the pump-induced amplitude and phase noise, respectively. A spectral phase-encoded time-spreading (SPECTS) O-CDMA testbed is described. The testbed employs a fiber-pigtailed, bulk-optics arrangement that utilizes a two-dimensional spatial light phase modulator for encoding multiple channels. The time-gated SPECTS O-CDMA receiver is composed of a nonlinear optical loop mirror (NOLM) and a nonlinear thresholder Experimentally measured performance is compared to numerical simulations. Finally, an optical frequency comb with 20-GHz spacing is shaped by an integrated silica arrayed-waveguide grating (AWG) pair to produce optical waveforms with high fidelity. Characterization of both the intensity and phase of the crafted opitical fields is accomplished with cross-correlation frequency-resolved optical gating (XFROG) which has been

  14. Development of laser induced breakdown spectroscopy instrumentatin for safeguards applications

    SciTech Connect

    Barefield Il, James E; Clegg, Samuel M; Le, Loan A; Lopez, Leon N

    2010-01-01

    In September 2006, a Technical Meeting on Application of Laser Spectrometry Techniques in IAEA Safeguards was held at IAEA headquarters (HQ). One of the principal recommendations from this meeting was the need to 'pursue the development of novel complementary access instrumentation based on laser induced breakdown spectroscopy (LIBS) for the detection of gaseous and solid signatures and indicators of nuclear fuel cycle processes and associated materials.' Pursuant to this recommendation the Department of Safeguards (SG) under the Division of Technical Support (SGTS) convened the Experts and Users Advisory Meeting on Laser Induced Breakdown Spectroscopy (LIBS) for Safeguards Applications. This meeting was held at IAEA HQ from July 7-11,2008 and hosted by the Novel Technologies Unit (NTU). The meeting was attended by 12 LIBS experts from the Czech Republic, the European Commission, France, the Republic of Korea, the United States of America, Germany, the United Kingdom of Great Britain, Canada, and Northern Ireland. After a presentation of the needs of the IAEA inspectors, the LIBS experts were in agreement that needs as presented could be partially or fully fulfilled using LIBS instrumentation. The needs of the IAEA inspectors were grouped in the following broad categories: (1) Improvements to in-field measurements/environmental sampling; (2) Monitoring status of activity in a Hot Cell; (3) Verifying status of activity at a declared facility via process monitoring; and (4) Need for pre-screening of environmental samples before analysis. Under the Department of Energy/National Nuclear Security Administration (DOE/NNSA) Next Generation Safeguards Initiative (NGSI) Los Alamos National Laboratory is exploring three potential applications of LIBS for international safeguards. As part of this work, we are developing: (1) a user-friendly man-portable LIBS system to characterize samples across a wide range of elements in the periodic table from hydrogen up to heavy elements

  15. Nanotube Films and Their Application For Mode-Locked Lasers

    NASA Astrophysics Data System (ADS)

    Rozhin, Alex G.; Ferrar, A. C.

    2009-03-01

    Carbon nanotubes (CNTs) exhibit strong saturable absorption, i.e. they become transparent under sufficiently intense light. This has great potential for applications in photonics. By tuning the nanotube diameter it is easy to tune the saturable absorption in a broad optical range of interest for telecommunications, medicine and military applications. The performance of CNTs based saturable absorbers depends on concentration, bundle size, and transparency of the matrix where CNTs are dispersed. CNT saturable absorbers can be produced by cheap wet chemistry and can be easily integrated into polymer photonic systems. Here, we review the fabrication and characterization of saturable absorber based on CNT-polymer optical composites [1,2,3]. We use strong ultrasonication to obtain CNT solutions. Such solutions with different nanotube bundle sizes are then studied by photoluminescence excitation spectroscopy [4]. We find that exciton energy transfer between semiconducting CNTs is an efficient carrier relaxation channel in the bundles [4]. This fingerprints and quantifies the presence of small bundles and allows us to optimize the solutions used for composites preparation. We demonstrate picosecond pulse generation in a nanotube mode-locked waveguide laser [5], as well as 125 fs generation in an erbium doped fiber laser. We also report a novel SWNT- polycarbonate polymer composite, with a absorption maximum at 1550 nm and a bandwidth of about 300 nm [6]. This has strong saturable absorption with saturation intensity of 7 MW/cm^2. We demonstrate the first SWNT-mode-locked widely tunable fibre ring laser [7]. This is achieved through the control of amplification at the specific transitions of the Er^3+ gain medium by placing a band-pass filter in a laser cavity [7]. [1] A. G. Rozhin et al. Phys. Stat. Sol. (b) 243, 3551 (2006). [2] V. Scardaci et al. Physica E 37, 115 (2007) [3] T. Hasan et al. J. Phys. Chem C 111, 12549 (2007) [4] P. H. Tan et al. Phys. Rev. Lett. 99

  16. Development of an Innovative Laser-Assisted Coating Process for Extending Lifetime of Metal Casting Dies. Final Report

    SciTech Connect

    Madhav Rao Gonvindaraju

    1999-10-18

    Die casting dies used in the metal casting industry fail due to thermal fatigue cracking accompanied by the presence of residual tensile stresses, corrosion, erosion and wear of die surfaces. This phase 1 SBIR Final Report summarize Karta Technologies research involving the development of an innovative laser coating technology for metal casting dies. The process involves depositing complex protective coatings of nanocrystalline powders of TiC followed by a laser shot peening. The results indicate a significant improvement in corrosion and erosion resistance in molten aluminum for H13 die casting die steels. The laser-coated samples also showed improved surface finish, a homogeneous and uniform coating mircrostructure. The technology developed in this research can have a significant impact on the casting industry by saving the material costs involved in replacing dies, reducing downtime and improving the quality.

  17. Fabrication of transparent ceramic laser media for high energy laser applications

    NASA Astrophysics Data System (ADS)

    Serivalsatit, Karn

    nanopowders with average particle size 40 and 60 nm, respectively. Transparent sesquioxide ceramics were successfully fabricated by vacuum sintering compacts of nanopowders at high temperature. These ceramics had relatively large grain sizes, ranging from tens to hundreds of micrometers, due to significant grain growth at the final stage of sintering. These large-grained ceramics tend to not offer significant enhancements to strength or thermal shock resistance that smaller grain-sized transparent ceramics afford. Sub-micrometer-grained highly transparent sesquioxide ceramics were fabricated using a two-step sintering process followed by hot isostatic pressing (HIP). This process yielded full densification of the sesquioxide ceramics with drastically reduced grain growth. These sub-micrometer-grained ceramics exhibited a transparency equivalent to that of single crystals in the near-infrared spectral. The microhardness and fracture toughness of transparent ceramics fabricated by this method were found to exceed those of transparent ceramics fabricated by conventional sintering. The single-crystal-like transmittance of the sub-micrometer-grained yttria ceramics in the visible and IR region with high mechanical properties is an important advancement for the use of these materials in more extreme environments, including high power laser systems where reduction of scattering and thermal shock resistance are critical.

  18. Red vertical cavity surface emitting lasers (VCSELs) for consumer applications

    NASA Astrophysics Data System (ADS)

    Duggan, Geoffrey; Barrow, David A.; Calvert, Tim; Maute, Markus; Hung, Vincent; McGarvey, Brian; Lambkin, John D.; Wipiejewski, Torsten

    2008-02-01

    There are many potential applications of visible, red (650nm - 690nm) vertical cavity surface emitting lasers (VCSELs) including high speed (Gb) communications using plastic optical fiber (POF), laser mouse sensors, metrology, position sensing. Uncertainty regarding the reliability of red VCSELs has long been perceived as the most significant roadblock to their commercialization. In this paper we will present data on red VCSELs optimized for performance and reliability that will allow exploitation of this class of VCSEL in a wide range of high volume consumer, communication and medical applications. VCSELs operating at ~665nm have been fabricated on 4" GaAs substrates using MOCVD as the growth process and using standard VCSEL processing technology. The active region is AlGaInP-based and the DBR mirrors are made from AlGaAs. Threshold currents are typically less than 2mA, the devices operate up to >60C and the light output is polarized in a stable, linear characteristic over all normal operating conditions. The 3dB modulation bandwidth of the devices is in excess of 3GHz and we have demonstrated the operation of a transceiver module operating at 1.25Gb/s over both SI-POF and GI-POF. Ageing experiments carried out using a matrix of current and temperature stress conditions allows us to estimate that the time to failure of 1% of devices (TT1%F) is over 200,000h for reasonable use conditions - making these red VCSELs ready for commercial exploitation in a variety of consumer-type applications. Experiments using appropriate pulsed driving conditions have resulted in operation of 665nm VCSELs at a temperature of 85°C whilst still offering powers useable for eye-safe free space and POF communications.

  19. Fluid mechanics of fusion lasers. Final report, September 11, 1978-June 5, 1980

    SciTech Connect

    Shwartz, J; Kulkarny, V A; Ausherman, D A; Legner, H H; Sturtevant, B

    1980-01-01

    Flow loop components required to operate continuous-flow, repetitively-pulsed CO/sub 2/ and KrF laser drivers for ICF were identified and their performance requirements were specified. It was found that the laser flow loops can have a major effect on the laser beam quality and overall efficiency. The pressure wave suppressor was identified as the most critical flow loop component. The performance of vented side-wall suppressors was evaluated both analytically and experimentally and found capable of meeting the performance requirements of the CO/sub 2/ and KrF fusion lasers. All other laser flow loop components are essentially similar to those used in conventional, low speed wind tunnels and are therefore well characterized and can be readily incorporated into fusion laser flow systems designs.

  20. Research of loss detection of optic path for laser ignition application

    NASA Astrophysics Data System (ADS)

    Liu, Jia; Liu, Haina; Jin, Jinjun; He, Zhexi; Wang, Xuefeng; Wang, Junlong

    2016-01-01

    We present some different kinds of the loss detection technologies of optic path for laser ignition application according to the recommend of reliability and security of the laser ignition system, such as single wavelength and dual wavelength. The factors of loss detection technology are discussed. The difficulty and uptrend of the laser ignition system are pointed out in this paper. The correlation research will be focused on the reliability of optic parts, applicability of environment and special fiber in the future.

  1. Mid-wave/long-wave infrared lasers and their sensing applications

    NASA Astrophysics Data System (ADS)

    Law, K. K.; Shori, R.; Miller, J. K.; Sharma, S.

    2011-06-01

    Many advances have been made recently in both solid-state and semiconductor based mid-wave infrared (MWIR) and long-wave infrared (LWIR) laser technologies, and there is an ever growing demand for these laser sources for Naval, DOD and homeland security applications. We will present various current and future programs and efforts at Naval Air Warfare Center Weapons Division (NAWCWD) on the development of high-power, broadly tunable MWIR/LWIR lasers for sensing applications.

  2. Injection-locked composite lasers for mm-wave modulation : LDRD 117819 final report.

    SciTech Connect

    Wendt, Joel Robert; Vawter, Gregory Allen; Raring, James; Tauke-Pedretti, Anna; Alford, Charles Fred; Skogen, Erik J.; Chow, Weng Wah; Cajas, Florante G.; Overberg, Mark E.; Torres, David L.; Peake, Gregory Merwin

    2010-09-01

    This report summarizes a 3-year LDRD program at Sandia National Laboratories exploring mutual injection locking of composite-cavity lasers for enhanced modulation responses. The program focused on developing a fundamental understanding of the frequency enhancement previously demonstrated for optically injection locked lasers. This was then applied to the development of a theoretical description of strongly coupled laser microsystems. This understanding was validated experimentally with a novel 'photonic lab bench on a chip'.

  3. Laser diagnostic experiments on KrF laser ablation plasma-plume dynamics relevant to manufacturing applications*

    NASA Astrophysics Data System (ADS)

    Gilgenbach, R. M.; Ching, C. H.; Lash, J. S.; Lindley, R. A.

    1994-05-01

    A brief review is given of the potential applications of laser ablation in the automotive and electronics manufacturing industries. Experiments are presented on KrF laser ablation of three materials relevant to manufacturing applications: aluminum metal vs aluminum-nitride (AlN) and alumina (Al2O3) ceramics. Plasma and neutral-atom diagnostic data are presented from resonant-holographic-interferometry, dye-laser-resonance-absorption photography, and HeNe laser deflection. Data show that plasma electron densities in excess of 1018 cm-3 exist in the ablation of AlN, with lower densities in Al and Al2O3. Aluminum neutral and ion expansion velocities are in the range of cm/μs. Ambipolar electric fields are estimated to be 5-50 V/cm.

  4. Direct solar-pumped iodine laser amplifier. Final report, 1 March 1984-28 February 1990

    SciTech Connect

    Han, K.S.; Hwang, I.H.

    1990-03-01

    The optimum conditions of a solar pumped iodine laser are found in this research for the case of a continuous wave operation and a pulsed operation. The optimum product of the pressure(p) inside the laser tube and the tube diameter(d) was pd=40 approx. 50 torr-cm on the contrary to the case of a high intensity flashlamp pumped iodine laser where the optimum value of the product is known to be pd=150 torr-cm. The pressure-diameter product is less than 1/3 of that of the high power iodine laser. During the research period, various laser materials were also studied for solar pumping. Among the laser materials, Nd:YAG is found to have the lowest laser threshold pumping intensity of about 200 solar constant. The Rhodamine 6G was also tested as the solar pumped laser material. The threshold pumping power was measured to be about 20,000 solar constant. The amplification experiment for a continuously pumped iodine laser amplifier was performed using Vortek solar simulator and the amplification factors were measured for single pass amplification and triple pass amplification of the 15 cm long amplifier tube. The amplification of 5 was obtained for the triple pass amplification.

  5. LASER BIOLOGY AND MEDICINE: Application of tunable diode lasers for a highly sensitive analysis of gaseous biomarkers in exhaled air

    NASA Astrophysics Data System (ADS)

    Stepanov, E. V.; Milyaev, Varerii A.

    2002-11-01

    The application of tunable diode lasers for a highly sensitive analysis of gaseous biomarkers in exhaled air in biomedical diagnostics is discussed. The principle of operation and the design of a laser analyser for studying the composition of exhaled air are described. The results of detection of gaseous biomarkers in exhaled air, including clinical studies, which demonstrate the diagnostic possibilities of the method, are presented.

  6. Laser surgery in dermatology with application of superthin optical fiber by contact and noncontact method

    NASA Astrophysics Data System (ADS)

    Garipova, A.; Denissov, I. A.; Solodovnikov, Vladimir; Digilova, I.

    1999-06-01

    At present nobody doubts the advantages of minor laser surgery over the conventional one.Bloodless manipulations, ablation, minor injury to the tissues while using laser equipment ensures its wide application in such fields as dermatology and cosmetology, especially since the semiconductor lasers because available at the technological market. No doubt CO2 and solid laser are still playing an important role, however, their imperfect fiber optic qualities limit their use in these field,s where advantages of diode lasers with flexible and fine quartz-polymeric optical fiber are obvious. The elaboration of new diode surgical lasers made it possible to invent new surgical equipment for solving many medical problems in the optimal way. Application of contact and noncontact laser methods in dermatology, gynecological plastic surgery and otolaryngology is discussed. A combined use of these methods demonstrates a positive effect on therapy results and healing time.

  7. Development and applications of laser-induced incandescence

    NASA Technical Reports Server (NTRS)

    Vanderwal, Randy L.; Dietrich, Daniel L.; Zhou, Zhiquang; Choi, Mun Y.

    1995-01-01

    Several NASA-funded investigations focus on soot processes and radiative influences of soot in diffusion flames given their simplicity, practical significance, and potential for theoretical modeling. Among the physical parameters characterizing soot, soot volume fraction, f(sub v), a function of particle size and number density, is often of chief practical interest in these investigations, as this is the geometrical property that directly impacts radiative characteristics and the temperature field of the flame and is basic to understanding soot growth and oxidation processes. Diffusion flames, however, present a number of challenges to the determination of f(sub v) via traditional extinction measurements. Laser-induced incandescence (LII) possesses several advantages compared to line-of-sight extinction techniques for determination of f(sub v). Since LII is not a line-of-sight technique, similar to fluorescence, it possesses geometric versatility allowing spatially resolved measurements of f(sub v) in real time in nonaxisymmetric systems without using deconvolution techniques. The spatial resolution of LII is determined by the detector and imaging magnification used. Neither absorption by polycyclic aromatic hydrocarbons (PAH's) nor scattering contributes to the signal. Temporal capabilities are limited only by the laser pulse and camera gate duration, with measurements having been demonstrated with 10 ns resolution. Because of these advantages, LII should be applicable to a variety of combustion processes involving both homogeneous and heterogeneous phases. Our work has focussed on characterization of the technique as well as exploration of its capabilities and is briefly described.

  8. Polymer based whispering gallery mode laser for biosensing applications

    NASA Astrophysics Data System (ADS)

    François, Alexandre; Riesen, Nicolas; Ji, Hong; Afshar V., Shahraam; Monro, Tanya M.

    2015-01-01

    Whispering gallery mode lasers are of interest for a wide range of applications and especially biological sensing, exploiting the dependence of the resonance wavelengths on the surrounding refractive index. Upon lasing, the Q factors of the resonances are greatly improved, enabling measurements of wavelength shifts with increased accuracy. A way forward to improve the performance of the refractive index sensing mechanism is to reduce the size of the optical resonator, as the refractive index sensitivity is inversely proportional to the resonator dimensions. However, as the lasing threshold is believed to depend on the Q factor among other parameters, and the reduction of the microresonator size results in lower Q, this poses additional challenges for reaching the lasing threshold. In this letter, we demonstrate lasing in 10 μm diameter dye doped polystyrene microspheres in aqueous solution, the smallest polystyrene microsphere lasers ever reported in these conditions. We also investigate the dependence of the lasing threshold on the Q factor by changing the refractive index surrounding the sphere, highlighting a much stronger dependency than initially reported.

  9. Applications of laser in ischemic heart disease in China

    NASA Astrophysics Data System (ADS)

    Chen, Mingzhe; Zhang, Yongzhen

    1999-09-01

    Current data demonstrate that laser coronary angioplasty is most useful in complex lesions not well suited for percutaneous transluminal coronary angioplasty (PTCA). It is not `stand-alone' procedure, and should be considered an adjunct to PTCA or stenting. To date, there are not data supporting reduction of restenosis. Direct myocardial revascularization (DMR), either transmyocardial revascularization (TMR) or percutaneous (catheter-based) myocardial revascularization (PMR), uses laser to create channels between ischemic myocardium and left ventricular cavity. Candidates include patients with chronic, severe, refractory angina and those unable to undergo angioplasty or bypass surgery because conduits or acceptable target vessels are lacking. Although the mechanisms of action of DMR have not yet been clearly elucidated, but several theories have been proposed, including channel patency, angiogenesis, and denervation. TMR, typically requiring open thoracotomy, is effective for improving myocardial perfusion and reducing angina. Pilot studies demonstrate that clinical application of PMR is feasible and safe and effective for decreasing angina. Late sequelae also remain to be determined. An ongoing randomized clinical trial is comparing PMR with conventional medical therapy in patients with severe, refractory angina and disease unamenable to angioplasty or bypass surgery.

  10. a Light-Weight Laser Scanner for Uav Applications

    NASA Astrophysics Data System (ADS)

    Tommaselli, A. M. G.; Torres, F. M.

    2016-06-01

    Unmanned Aerial Vehicles (UAV) have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP) as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

  11. Laser-induced breakdown spectroscopy in industrial and security applications

    SciTech Connect

    Bol'shakov, Alexander A.; Yoo, Jong H.; Liu Chunyi; Plumer, John R.; Russo, Richard E.

    2010-05-01

    Laser-induced breakdown spectroscopy (LIBS) offers rapid, localized chemical analysis of solid or liquid materials with high spatial resolution in lateral and depth profiling, without the need for sample preparation. Principal component analysis and partial least squares algorithms were applied to identify a variety of complex organic and inorganic samples. This work illustrates how LIBS analyzers can answer a multitude of real-world needs for rapid analysis, such as determination of lead in paint and children's toys, analysis of electronic and solder materials, quality control of fiberglass panels, discrimination of coffee beans from different vendors, and identification of generic versus brand-name drugs. Lateral and depth profiling was performed on children's toys and paint layers. Traditional one-element calibration or multivariate chemometric procedures were applied for elemental quantification, from single laser shot determination of metal traces at {approx}10 {mu}g/g to determination of halogens at 90 {mu}g/g using 50-shot spectral accumulation. The effectiveness of LIBS for security applications was demonstrated in the field by testing the 50-m standoff LIBS rasterizing detector.

  12. Development of laser-plasma diagnostics using ultrafast atomic-scale dynamics. 96-ERD-046 final report

    SciTech Connect

    Bolton, P.R.; Kulander, K.C.; Boreham, B.W.

    1997-03-01

    Ultrashort laser pulse systems allow examination of intense, ultrafast laser-plasma interactions. More specifically, intense laser irradiation can induce short xuv/x-ray bursts from the surface of condensed phase targets. Ultrafast xuv/x-ray detection is needed to understand laser-plasma interactions in this dynamic regime. Support of the Stockpile Stewardship and Management Program requires this critical understanding. Our effort here has been to extend understanding of atomic-scale dynamics in such environments with the goal of developing next generation ultrafast xuv/x-ray diagnostics where the sensors will be the atoms and ions themselves and the time resolution will approach that of the induced atomic transitions ({approx} a few femtoseconds). Pivotal contributions to the rapidly developing field of highly nonperturbative interactions of ultrashort pulse lasers with atoms/ions have been made at this laboratory. In the visible/infrared wavelength regions the temporal and spectral content of ultrashort laser pulses are now reliably monitored within a single pulse using frequency resolved optical gating (FROG) which is based on rapid nonlinear optical processes such as the Kerr effect. New applications of this basic concept are still being developed. Corresponding detection for the xuv/x-ray wavelengths does not exist and is urgently needed in many laboratory programs. The FROG technique cannot be applied in the xuv/x-ray region. Current x-ray streak camera technology is limited to {approx}0.5 picosecond resolution.

  13. Laser-induced thermal bubbles for microfluidic applications.

    PubMed

    Zhang, Kai; Jian, Aoqun; Zhang, Xuming; Wang, Yu; Li, Zhaohui; Tam, Hwa-Yaw

    2011-04-01

    We present a unique bubble generation technique in microfluidic chips using continuous-wave laser-induced heat and demonstrate its application by creating micro-valves and micro-pumps. In this work, efficient generation of thermal bubbles of controllable sizes has been achieved using different geometries of chromium pads immersed in various types of fluid. Effective blocking of microfluidic channels (cross-section 500 × 40 μm(2)) and direct pumping of fluid at a flow rate of 7.2-28.8 μl h(-1) with selectable direction have also been demonstrated. A particular advantage of this technique is that it allows the generation of bubbles at almost any location in the microchannel and thus enables microfluidic control at any point of interest. It can be readily integrated into lab-on-a-chip systems to improve functionality.

  14. [Objective evaluation the application of femtosecond laser in cataract surgery].

    PubMed

    Liu, Y Z

    2016-02-01

    Femtosecond laser-assisted cataract surgery (FLACS) is a novel technology and the biggest revolution in the field of cataract in the latest several years. However, increasing large-scale population randomized controlled trials (RCT) have demonstrated that FLACS does not provide significant advantages over conventional phacoemulsification cataract surgery (CPCS) for common cataract patients. Furthermore, the cost and space requirement of the femtosecond equipment are another two limitations for the universal application of FSL in cataract surgery. However, FLACS may be beneficial for complex cataract situations, such as lens dislocation, zonular laxity, traumatic cataract, low preoperative endothelial cell values, and significant corneal astigmatism. With the progress of science and technology, FLACS can be expected to achieve integration with phacoemulsification systems, and equipment costs can be reduced, making it more widely used in clinical practice in the future. PMID:26906700

  15. Design investigation of solar powered lasers for space applications

    NASA Technical Reports Server (NTRS)

    Taussig, R.; Bruzzone, C.; Quimby, D.; Nelson, L.; Christiansen, W.; Neice, S.; Cassady, P.; Pindroh, A.

    1979-01-01

    The feasibility of solar powered lasers for continuous operation in space power transmission was investigated. Laser power transmission in space over distances of 10 to 100 thousand kilometers appears possible. A variety of lasers was considered, including solar-powered GDLs and EDLs, and solar-pumped lasers. An indirect solar-pumped laser was investigated which uses a solar-heated black body cavity to pump the lasant. Efficiencies in the range of 10 to 20 percent are projected for these indirect optically pumped lasers.

  16. Laser quality single crystal specimens. Final report, 27 September-30 November 1980

    SciTech Connect

    Pollak, T.

    1980-12-15

    Research and development on the crystalline laser host, YLF (LiYF4), was completed during this program. The study involved crystal growth and sample fabrication of rare earth doped YLF. These materials were then evaluated at NRL. A total of 16 laser samples, eight different compositions, were processed during this contract period.

  17. Geoscience Laser Altimeter System (GLAS) Final Test Report of DM LHP TV Testing

    NASA Technical Reports Server (NTRS)

    Baker, Charles

    2000-01-01

    Two loop heat pipes (LHPs) are to be used for thermal control of the Geoscience Laser Altimeter System (GLAS), planned for flight in 2001. One LHP will be used to transport 100 W from a laser to the radiator, the other will transport 210 W from electronic boxes to the radiator. In order to verify the LHP design for the GLAS application, an LHP Development Model has been fabricated, and ambient and thermal vacuum tested. Two aluminum blocks of 15 kg and 30 kg, respectively, were attached to the LHP to simulate the thermal masses connected to the heat sources. A 20 W starter heater was installed on the evaporator to aid the loop startup. A new concept to thermally couple the vapor and liquid line was also incorporated in the LHP design. Such a thermal coupling would reduce the power requirement on the compensation chamber in order to maintain the loop set point temperature. To avoid freezing of the liquid in the condenser during cold cases, propylene was selected as the working fluid. The LHP was tested under reflux mode and with adverse elevation. Tests conducted included start-up, power cycle, steady state and transient operation during hot and cold cases, and heater power requirements for the set point temperature control of the LHP. Test results showed very successful operation of the LHP under all conditions. The 20 W starter heater proved necessary in order to start the loop when a large thermal mass was attached to the evaporator. The thermal coupling between the liquid line and the vapor line significantly reduced the heater power required for loop temperature control, which was less than 5 watts in all cases, including a cold radiator. The test also demonstrated successful operation with a propylene working fluid, with successful startups with condenser temperatures as low as 100 C. Furthermore, the test demonstrated accurate control of the loop operating temperature within +/- 0.2 C, and a successful shutdown of the loop during the survival mode of

  18. Laser fusion research: Generation of suprathermal particles, laser radiation harmonics, and d. c. magnetic fields. Final report

    SciTech Connect

    Stefan, V.

    1989-11-01

    Understanding of processes connected with generation of suprathermal particles, harmonics and magnetic fields has a crucial importance in establishing of diagnostic methods for laser-plasma coupling and overall understanding of the interaction physics. This work is an attempt to provide a comprehensive review of the field, covering theoretical, experimental and simulation aspects of the subject. Within each section, material is organized into three categories: (a) general background giving general formulation of the problem as well as its general solution, (b) historical survey, including present status with comments on needed future developments, and (c) simulation and experimental results. All theoretical results are given in a relatively simple form in order to be convenient for analysis of experimental data and for evaluation of their significance as a foundation for new diagnostic methods of laser plasmas.

  19. Lasers, their development, and applications at M. I. T. Lincoln Laboratory

    SciTech Connect

    Rediker, R.H.; Melngailis, I.; Mooradian, A.

    1984-01-01

    A historical account of the work on lasers at MIT Lincoln Laboratory is presented. Highlighted are the efforts that led to the coinvention of the semiconductor laser and the Laboratory's later role in establishing the feasibility of GaInAsP/InP semiconductor lasers for use in fiber telecommunications at 1.3-1.5 ..mu..m wavelengths. Descriptions of other important developments include tunable lead-salt semiconductor and solid-state lasers for spectroscopy and LIDAR applications, respectively, as well as ultrastable CO/sub 2/ lasers for coherent infrared radar.

  20. Lasers, their development, and applications at M.I.T. Lincoln Laboratory

    NASA Technical Reports Server (NTRS)

    Rediker, R. H.; Melngailis, I.; Mooradian, A.

    1984-01-01

    A historical account of the work on lasers at MIT Lincoln Laboratory is presented. Highlighted are the efforts that led to the coinvention of the semiconductor laser and the Laboratory's later role in establishing the feasibility of GaInAsP/InP semiconductor lasers for use in fiber telecommunications at 1.3-1.5 micron wavelengths. Descriptions of other important developments include tunable lead-salt semiconductor and solid-state lasers for spectroscopy and LIDAR applications, respectively, as well as ultrastable CO2 lasers for coherent infrared radar.

  1. Polygon Scanner System for Ultra Short Pulsed Laser Micro-Machining Applications

    NASA Astrophysics Data System (ADS)

    De Loor, R.

    Ultra short pulsed lasers have gained acceptance in micro-machining applications and many processes have been developed in the lab. Transferring the technology to the manufacturing floor started few years ago as soon as relatively high average power (> 5W) lasers became available. Now that high repetition rates and average powers of 50 Watt and more are reaching the market, the commercially available galvo based laser scanners systems limit the efficient use of this expensive laser power. We present a novel polygon based scanner system incorporating laser and scanner synchronization enabling writing speeds of 50 m/sec and higher.

  2. Laser-induced magnetic fields in ICF capsules, Final Report, DE-FG02-08ER85128, Phase 1

    SciTech Connect

    Lindman, Erick L

    2009-11-05

    Laser-induced magnetic fields in ICF capsules Final Report, DE-FG02-08ER85128, Phase 1 E. L. LINDMAN, Otowi Technical Services, Los Alamos, NM. The performance of an inertial-confinement-fusion (ICF) capsule can be improved by inserting a magnetic field into it before compressing it [Kirkpatrick, et al., Fusion Technol. 27, 205 (1995)]. To obtain standoff in an ICF power generator, a method of inserting the field without the use of low-inductance leads attached to the capsule is desired. A mechanism for generating such a field using a laser was discovered in Japan [Sakagami, et al., Phys. Rev. Lett. 42, 839 (1979), Kolodner and Yablonovitch, Phys. Rev. Lett. 43, 1402 (1979)] and studied at Los Alamos in the 1980s [M. A. Yates, et al., Phys. Rev. Lett. 49, 1702 (1982); Forslund and Brackbill, Phys. Rev. Lett. 48, 1614 (1982)]. In this mechanism, a p-polarized laser beam strikes a solid target producing hot electrons that are accelerated away from the target surface by resonant absorption. An electric field is created that returns the hot electrons to the target. But, they do not return to the target along the same trajectory on which they left. The resulting current produces a toroidal magnetic field that was observed to spread over a region outside the hot spot with a radius of a millimeter. No experimental measurements of the magnetic field strength were performed. Estimates from computer simulation suggest that field strengths in the range of 1 to 10 Mega gauss (100 to 1000 Tesla) were obtained outside of the laser spot. To use this mechanism to insert a magnetic field into an ICF capsule, the capsule must be redesigned. In one approach, a central conductor is added, a toroidal gap is cut in the outer wall and the DT fuel is frozen on the inner surface of the capsule. The capsule is dropped into the reaction chamber and struck first with the laser that generates the magnetic field. The laser hot spot is positioned at the center of the toroidal gap. As the

  3. Application of laser-based profilometry to tubing in power generating utilities

    NASA Astrophysics Data System (ADS)

    Doyle, James L.

    1995-05-01

    Over the past several years lasers have been employed in an ever widening number of applications in an incredibly diverse set of markets. In the area of nondestructive testing, however, laser-based systems have only recently made inroads into the commercial markets. About ten years ago QUEST Integrated, Inc., began working with the U.S. Navy to adapt the principal of laser triangulation to solve a serious maintenance related problem. The internal surfaces of marine boiler tubes were experiencing pitting and corrosion which had resulted in catastrophic shipboard failures. At that time, conventional visual methods only allowed operators to inspect the first eighteen inches of the tube using a rigid borescope. If any pits were located, a mechanical stylus mechanism was used to obtain an approximate depth measurement of the pit. The condition of the balance of the tube was then extrapolated based on this extremely limited amount of information. Often the worst pitting was found in the bends of the tube, which could not be inspected by the visual method. Finally, a catastrophic boiler failure on an aircraft carrier resulted in the initiation of a search by the U.S. Navy for a better solution. Quest was contracted to develop an articulated probe which could negotiate the full length of a boiler tube with multiple bends, and generate a complete digital map of the inside surface. A key requirement of this probe would be rapid and quantitative measurement of internal features such as ID pits and corrosion. In 1987 QUEST delivered the first laser- optic tube inspection system to the U.S. Navy for use in marine boiler tubes. The Laser Optic Tube Inspection System (LOTISTM) was immediately put to use and paid for itself many times over in reduced maintenance costs. Over the next six years several generations of LOTIS were developed for the U.S. Navy, each one providing more capabilities, improved inspection speeds, and more user friendly operator interface. Today, LOTIS is

  4. Spectroscopic investigation of materials for frequency-agile laser systems. Final report, 15 January 1982-14 January 1985

    SciTech Connect

    Powell, R.C.

    1985-01-01

    This research involves the use of laser-spectroscopy techniques such as four-wave mixing, multiphoton absorption, time-resolved site-selection spectroscopy, and holography to characterize dynamical optical processes such as energy transfer, exciton migration, radiation-less relaxation, and the photorefractive effect. In addition, a significant effort was spent in the synthesis and characterization of new types of materials for tunable laser applications. The materials investigated include alexandrite, titanium-doped sapphire, lithium niobate, neodymium pentaphosphate, rhodium-doped rubidium calcium fluoride, manganese silicate, and neodymium-doped garnet crystals and glasses.

  5. Laser rods with undoped, flanged end-caps for end-pumped laser applications

    DOEpatents

    Meissner, Helmuth E.; Beach, Raymond J.; Bibeau, Camille; Sutton, Steven B.; Mitchell, Scott; Bass, Isaac; Honea, Eric

    1999-01-01

    A method and apparatus for achieving improved performance in a solid state laser is provided. A flanged, at least partially undoped end-cap is attached to at least one end of a laserable medium. Preferably flanged, undoped end-caps are attached to both ends of the laserable medium. Due to the low scatter requirements for the interface between the end-caps and the laser rod, a non-adhesive method of bonding is utilized such as optical contacting combined with a subsequent heat treatment of the optically contacted composite. The non-bonded end surfaces of the flanged end-caps are coated with laser cavity coatings appropriate for the lasing wavelength of the laser rod. A cooling jacket, sealably coupled to the flanged end-caps, surrounds the entire length of the laserable medium. Radiation from a pump source is focussed by a lens duct and passed through at least one flanged end-cap into the laser rod.

  6. Electrochemical impedance spectroscopy and laser photoselectivity with gold nanoparticles for food applications

    NASA Astrophysics Data System (ADS)

    Chee, Grace

    With consistently higher and stricter standards for food quality and safety, it is becoming increasingly necessary to be able to quickly and easily determine certain properties of products in order to keep up with and maintain these standards. This master’s thesis is presented in three chapters. First, an overview of the theoretical background, current applications, and new technologies related to taking physiochemical property measurements of food, and various treatment methods used for food safety purposes. In the second chapter, electrochemical impedance spectroscopy (EIS) is used to find the dielectric (DE) constants and other physiochemical properties of potatoes in order to make quick adjustments to improve the microwave processing technique used for potato chipping. Finally, the third chapter introduces the use of a carbon dioxide laser system in conjunction with a two-ZnSe lens beam expander and functionalized gold nanoparticles to specifically target and kill E. coli in food samples.

  7. Applications of lasers to the solution of environmental problems

    SciTech Connect

    Allen, L.; Pang, H.-M.; Edelson, M.C.

    1995-12-31

    This presentation will focus on current work in the Ames Laboratory where laser ablation is being used for both analytical sampling and metal surface cleaning. Examples will be presented demonstrating the utility of optical spectroscopy for monitoring laser ablation processes.

  8. 38 CFR 11.128 - Veteran dies without having filed application for final settlement.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2012-07-01 2012-07-01 false Veteran dies without... Amended (pub. L. 120, 68th Cong.) § 11.128 Veteran dies without having filed application for final settlement. If the veteran dies without having filed application for final settlement under the...

  9. 38 CFR 11.128 - Veteran dies without having filed application for final settlement.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2013-07-01 2013-07-01 false Veteran dies without... Amended (pub. L. 120, 68th Cong.) § 11.128 Veteran dies without having filed application for final settlement. If the veteran dies without having filed application for final settlement under the...

  10. 38 CFR 11.128 - Veteran dies without having filed application for final settlement.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2010-07-01 2010-07-01 false Veteran dies without... Amended (pub. L. 120, 68th Cong.) § 11.128 Veteran dies without having filed application for final settlement. If the veteran dies without having filed application for final settlement under the...

  11. 38 CFR 11.128 - Veteran dies without having filed application for final settlement.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2011-07-01 2011-07-01 false Veteran dies without... Amended (pub. L. 120, 68th Cong.) § 11.128 Veteran dies without having filed application for final settlement. If the veteran dies without having filed application for final settlement under the...

  12. 38 CFR 11.128 - Veteran dies without having filed application for final settlement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 1 2014-07-01 2014-07-01 false Veteran dies without... Amended (pub. L. 120, 68th Cong.) § 11.128 Veteran dies without having filed application for final settlement. If the veteran dies without having filed application for final settlement under the...

  13. Application of copper vapour lasers for controlling activity of uranium isotopes

    SciTech Connect

    Barmina, E V; Sukhov, I A; Lepekhin, N M; Priseko, Yu S; Filippov, V G; Simakin, Aleksandr V; Shafeev, Georgii A

    2013-06-30

    Beryllium nanoparticles are generated upon ablation of a beryllium target in water by a copper vapour laser. The average size of single crystalline nanoparticles is 12 nm. Ablation of a beryllium target in aqueous solutions of uranyl chloride leads to a significant (up to 50 %) decrease in the gamma activity of radionuclides of the uranium-238 and uranium-235 series. Data on the recovery of the gamma activity of these nuclides to new steady-state values after laser irradiation are obtained. The possibility of application of copper vapour lasers for radioactive waste deactivation is discussed. (laser applications and other topics in quantum electronics)

  14. Final Scientific and Technical Report - Practical Fiber Delivered Laser Ignition Systems for Vehicles

    SciTech Connect

    Yalin, Azer

    2014-03-30

    Research has characterized advanced kagome fiber optics for their use in laser ignition systems. In comparison to past fibers used in laser ignition, these fibers have the important advantage of being relatively bend-insensitivity, so that they can be bent and coiled without degradation of output energy or beam quality. The results are very promising for practical systems. For pulse durations of ~12 ns, the fibers could deliver >~10 mJ pulses before damage onset. A study of pulse duration showed that by using longer pulse duration (~20 – 30 ns), it is possible to carry even higher pulse energy (by factor of ~2-3) which also provides future opportunities to implement longer duration sources. Beam quality measurements showed nearly single-mode output from the kagome fibers (i.e. M2 close to 1) which is the optimum possible value and, combined with their high pulse energy, shows the suitability of the fibers for laser ignition. Research has also demonstrated laser ignition of an engine including reliable (100%) ignition of a single-cylinder gasoline engine using the laser ignition system with bent and coiled kagome fiber. The COV of IMEP was <2% which is favorable for stable engine operation. These research results, along with the continued reduction in cost of laser sources, support our commercial development of practical laser ignition systems.

  15. Final Report: Laser-Material Interactions Relevant to Analytic Spectroscopy of Wide Band Gap Materials

    SciTech Connect

    Dickinson, J. T.

    2014-04-05

    We summarize our studies aimed at developing an understanding of the underlying physics and chemistry in terms of laser materials interactions relevant to laser-based sampling and chemical analysis of wide bandgap materials. This work focused on the determination of mechanisms for the emission of electrons, ions, atoms, and molecules from laser irradiation of surfaces. We determined the important role of defects on these emissions, the thermal, chemical, and physical interactions responsible for matrix effects and mass-dependent transport/detection. This work supported development of new techniques and technology for the determination of trace elements contained such as nuclear waste materials.

  16. Noncritically phase-matched fourth-harmonic generation of Nd:glass lasers and design of final optics assembly.

    PubMed

    Jiang, Xiuqing; Ji, Lailin; Liu, Dong; Tang, Shunxing; Zhu, Baoqiang; Lin, Zunqi

    2016-05-20

    The noncritically phase-matched (NCPM) fourth-harmonic generation (FHG) with partially deuterated dihydrogen phosphate (KD*P) crystal at an Nd:glass laser radiation wavelength of 1053.1 nm has been confirmed. NCPM FHG has been achieved in 70% and 65% deuterated KD*P crystal at the temperature of 17.7°C and 29.3°C, respectively. The angular acceptance of 70% and 65% deuterated KD*P crystals fixed at their NCPM temperature were measured, which were 53 and 55 mrad, respectively. The application of the NCPM FHG in a high-power laser facility for inertial confinement fusion is also discussed. Based on the theoretical analysis, the NCPM KD*P can be placed after the focus lens; thus, the laser-induced damage of a fused-silica lens at ultraviolet can be avoided. PMID:27411142

  17. Organization of the topical meeting on tunable solid-state lasers. Held in North Falmouth, Massachusetts on May 1-3 1989. Final report, 30 August 1988-30 August 1989

    SciTech Connect

    Not Available

    1989-08-30

    Progress and interest in solid-state lasers generally, and in tunable solid state-lasers specifically, continues to expand. Applications of these lasers include spectroscopy, remote sensing, ranging and imaging, and medicine. New solid-state materials are providing lasers with higher output power, broader tunability, and more-efficient pumping schemes. The quantum electronics and crystal-chemistry properties of these new materials are leading to enhanced laser performance. At the meeting, sessions were held on sapphire, novel laser schemes, Cr lasers, forsterite and excited-state absorption, solid-state lasers for specialized applications, alexandrite lasers, Cr-related issues, diode pumped lasers, nonlinear frequency conversion, 1.3-micrometer Nd lasers, infrared lasers and energy transfer, 2-micrometer lasers, rare earth laser materials, and Er lasers.

  18. Application systems for intracorporeal laser-induced shockwave lithotripsy using the Nd:YAG Q-switched laser.

    PubMed

    Frank, F; Eichenlaub, M; Hessel, S; Wondrazek, F

    1990-10-01

    For laser-induced shockwave lithotripsy, the electromagnetic energy of a laser light pulse is converted intracorporeally into the acoustic energy of a shockwave. The lithotriptor is based on a specially developed, Q-switched Nd:YAG laser whose high power light pulses (70 mJ, 25 nsec) are coupled into a flexible quartz fiber with a core diameter of 600 mum. Using focusing elements, energy densities higher than 6 x 10 5 J m -2 can be achieved, resulting in an optical breakdown in water followed by a shockwave. As a result of different absorption mechanisms, the breakdown threshold can be decreased by placing a metallic target into the laser beam. The different shockwave formations of such optomechanical transducers have been measured. First clinical applications have been performed.

  19. A scalable high-energy diode-pumped solid state laser for laser-plasma interaction science and applications

    NASA Astrophysics Data System (ADS)

    De Vido, M.; Ertel, K.; Mason, P. D.; Banerjee, S.; Phillips, P. J.; Butcher, T. J.; Smith, J. M.; Shaikh, W.; Hernandez-Gomes, C.; Greenhalgh, R. J. S.; Collier, J. L.

    2016-05-01

    Laser systems efficiently generating nanosecond pules at kJ energy levels and at multi-Hz repetition rates are required in order to translate laser-plasma interactions into practical applications. We have developed a scalable, actively-cooled diode-pumped solid state laser amplifier design based on a multi-slab ceramic Yb:YAG architecture called DiPOLE (Diode-Pumped Optical Laser for Experiments) capable of meeting such requirements. We demonstrated 10.8 J, 10 Hz operation at 1030 nm using a scaled-down prototype, reaching an optical-to-optical efficiency of 22.5%. Preliminary results from a larger scale version, delivering 100 J pulse energy at 10 Hz, are also presented.

  20. Programmable phase plate for tool modification in laser machining applications

    DOEpatents

    Thompson Jr., Charles A.; Kartz, Michael W.; Brase, James M.; Pennington, Deanna; Perry, Michael D.

    2004-04-06

    A system for laser machining includes a laser source for propagating a laser beam toward a target location, and a spatial light modulator having individual controllable elements capable of modifying a phase profile of the laser beam to produce a corresponding irradiance pattern on the target location. The system also includes a controller operably connected to the spatial light modulator for controlling the individual controllable elements. By controlling the individual controllable elements, the phase profile of the laser beam may be modified into a desired phase profile so as to produce a corresponding desired irradiance pattern on the target location capable of performing a machining operation on the target location.

  1. High power laser and materials investigation. Final report, 31 July 1978-28 October 1979

    SciTech Connect

    Chicklis, E.P.; Folweiler, R.C.; Pollak, T.M.; Baer, J.

    1980-06-01

    This is a combined study of resonant pumped solid state lasers as fusion drivers, and the development of crystalline optical materials suitable for propagation of the high peak powers associated with laser fusion research. During this period of study the concept of rare gas halide lasers was first demonstrated by the lasing of Tm:YLF at 453 nm pumped by the 353 nm energy of XeF. Excited stata densities of 5 x 10/sup 18/ cm/sup -3/ have been attained and spectroscopic measurements show that up to 60% of the pump energy can be converted into useful stored energy. Alternative lasers and pumping schemes are also discussed. In all cases the potential RGH/SS systems are evaluated in respect to internal efficiency and heat loading.

  2. New therapeutic modalities of retinal laser injury. Final report, 1 Mar 89-1 Mar 92

    SciTech Connect

    Lam, T.T.; Tso, M.O.

    1992-03-31

    Efficacies of three different regimens of high dose of methylprednisolone (MP) treatment on laser-induced non-hemorrhage retinal injury and tissue plasminogen activator (t-PA) in sub-retinal hemorrhage laser injury were evaluated in a sub-human primate model and a rat model respectively. Clinical, histopathological, and morphometric criteria were employed for evaluating the efficacy of MP. High dose and prolonged treatment (4 days) was the most effective regimen while high dose for 8 hours showed limited effect in non-hemorrhagic retinal injury. Intravitreal t-PA showed no apparent beneficial effect in sub-retinal hemorrhage after laser injury. Hence, patients with laser retinal injury may benefit from high dose MP treatment for an appropriate period of time.

  3. An application of laser-plasma acceleration: towards a free-electron laser amplification

    NASA Astrophysics Data System (ADS)

    Couprie, M. E.; Labat, M.; Evain, C.; Marteau, F.; Briquez, F.; Khojoyan, M.; Benabderrahmane, C.; Chapuis, L.; Hubert, N.; Bourassin-Bouchet, C.; El Ajjouri, M.; Bouvet, F.; Dietrich, Y.; Valléau, M.; Sharma, G.; Yang, W.; Marcouillé, O.; Vétéran, J.; Berteaud, P.; El Ajjouri, T.; Cassinari, L.; Thaury, C.; Lambert, G.; Andriyash, I.; Malka, V.; Davoine, X.; Tordeux, M. A.; Miron, C.; Zerbib, D.; Tavakoli, K.; Marlats, J. L.; Tilmont, M.; Rommeluère, P.; Duval, J. P.; N'Guyen, M. H.; Rouqier, A.; Vanderbergue, M.; Herbeaux, C.; Sebdouai, M.; Lestrade, A.; Leclercq, N.; Dennetière, D.; Thomasset, M.; Polack, F.; Bielawski, S.; Szwaj, C.; Loulergue, A.

    2016-03-01

    The laser-plasma accelerator (LPA) presently provides electron beams with a typical current of a few kA, a bunch length of a few fs, energy in the few hundred MeV to several GeV range, a divergence of typically 1 mrad, an energy spread of the order of 1%, and a normalized emittance of the order of π.mm.mrad. One of the first applications could be to use these beams for the production of radiation: undulator emission has been observed but the rather large energy spread (1%) and divergence (1 mrad) prevent straightforward free-electron laser (FEL) amplification. An adequate beam manipulation through the transport to the undulator is then required. The key concept proposed here relies on an innovative electron beam longitudinal and transverse manipulation in the transport towards an undulator: a ‘demixing’ chicane sorts the electrons according to their energy and reduces the spread from 1% to one slice of a few ‰ and the effective transverse size is maintained constant along the undulator (supermatching) by a proper synchronization of the electron beam focusing with the progress of the optical wave. A test experiment for the demonstration of FEL amplification with an LPA is under preparation. Electron beam transport follows different steps with strong focusing with permanent magnet quadrupoles of variable strength, a demixing chicane with conventional dipoles, and a second set of quadrupoles for further focusing in the undulator. The FEL simulations and the progress of the preparation of the experiment are presented.

  4. Lightweight solar array blanket tooling, laser welding and cover process technology. Final Report

    SciTech Connect

    Dillard, P.A.

    1983-01-01

    A two phase technology investigation was performed to demonstrate effective methods for integrating 50 micrometer thin solar cells into ultralightweight module designs. During the first phase, innovative tooling was developed which allows lightweight blankets to be fabricated in a manufacturing environment with acceptable yields. During the second phase, the tooling was improved and the feasibility of laser processing of lightweight arrays was confirmed. The development of the cell/interconnect registration tool and interconnect bonding by laser welding is described.

  5. Rare gas halide lasers for fusion. Final technical report, 1 March 1979-29 February 1980

    SciTech Connect

    Duzy, C; Hsia, J; Hyman, H; Jacob, J; Klimek, D; Parks, J; Trainor, D

    1980-04-01

    In an effort to reliably extend the understanding of KrF* lasers, we collected specific, detailed experimental data and carried out theoretical calculations to explore and document those issues we identified as likely to be important in the short pulse operating regime. These included the effects of: (1) fuel burnup, (2) electron quenching, (3) gain/absorption at high current densities, (4) photoionization, (5) accessibility of the lying levels of KrF by laser flux, (6) temperature on fluorescence efficiency.

  6. Review of laser filter materials. Final report, October 1987-September 1988

    SciTech Connect

    Welch, J.A.

    1989-09-26

    This report presents a discussion of laser eye-protection filtering materials. Four classes of filters are evaluated for immediate and future filtering capabilities. Salient features required for near-term multi-wavelength filtering are discussed in general, and the effectiveness of several filter materials as laser protection is assessed. Spectral illuminances for the most promising eye-protection filters are computed for representative day- and night-lighting conditions to approximate visual acuity.

  7. Studies on laser peening of spring steel for automotive applications

    NASA Astrophysics Data System (ADS)

    Ganesh, P.; Sundar, R.; Kumar, H.; Kaul, R.; Ranganathan, K.; Hedaoo, P.; Tiwari, Pragya; Kukreja, L. M.; Oak, S. M.; Dasari, S.; Raghavendra, G.

    2012-05-01

    Present experimental laser shock peening study on SAE 9260 spring steel, performed with an in-house developed 2.5 J/7 ns pulsed Nd:YAG laser, aimed to evaluate laser shock peening process as a possible alternative to existing shot peening practice for enhancing fatigue life of leaf springs. In the investigated range of process parameters, laser shock peening yielded largely comparable magnitude of surface compressive stress and shallower compressed surface layer than those achieved with existing shot peening practice. In contrast to considerably rougher shot peened surface with numerous defects, laser shock peening produced largely unaltered surface finish without peening-induced defects. With respect to shot peening, laser shock peening brought about significant increase in fatigue life. Improved fatigue performance of laser shock peened specimens is attributed to their better surface finish without peening-induced surface defects, which were potential fatigue crack nucleation sites in shot peened specimens.

  8. Optical and laser spectroscopic diagnostics for energy applications

    NASA Astrophysics Data System (ADS)

    Tripathi, Markandey Mani

    The continuing need for greater energy security and energy independence has motivated researchers to develop new energy technologies for better energy resource management and efficient energy usage. The focus of this dissertation is the development of optical (spectroscopic) sensing methodologies for various fuels, and energy applications. A fiber-optic NIR sensing methodology was developed for predicting water content in bio-oil. The feasibility of using the designed near infrared (NIR) system for estimating water content in bio-oil was tested by applying multivariate analysis to NIR spectral data. The calibration results demonstrated that the spectral information can successfully predict the bio-oil water content (from 16% to 36%). The effect of ultraviolet (UV) light on the chemical stability of bio-oil was studied by employing laser-induced fluorescence (LIF) spectroscopy. To simulate the UV light exposure, a laser in the UV region (325 nm) was employed for bio-oil excitation. The LIF, as a signature of chemical change, was recorded from bio-oil. From this study, it was concluded that phenols present in the bio-oil show chemical instability, when exposed to UV light. A laser-induced breakdown spectroscopy (LIBS)-based optical sensor was designed, developed, and tested for detection of four important trace impurities in rocket fuel (hydrogen). The sensor can simultaneously measure the concentrations of nitrogen, argon, oxygen, and helium in hydrogen from storage tanks and supply lines. The sensor had estimated lower detection limits of 80 ppm for nitrogen, 97 ppm for argon, 10 ppm for oxygen, and 25 ppm for helium. A chemiluminescence-based spectroscopic diagnostics were performed to measure equivalence ratios in methane-air premixed flames. A partial least-squares regression (PLS-R)-based multivariate sensing methodology was investigated. It was found that the equivalence ratios predicted with the PLS-R-based multivariate calibration model matched with the

  9. Application of laser radiation in decoration and marking of ceramic products

    NASA Astrophysics Data System (ADS)

    Chmielewska, D.; Gebel, R.; Szamałek, K.; Olszyna, A.; Marczak, J.; Sarzyński, A.; Strzelec, M.

    2013-01-01

    In cooperation with the Institute of Optoelectronics MUT, the Institute of Ceramics and Building Materials conducts work on laser decoration of ceramic products. Two methods are under development: laser activation and laser sintering. The activation method is based on change of color of specially prepared ceramic material due only to illumination by laser beam. Laser sintering is a deposition welding process in which a layer of ceramic powder is deposited on the substrate material, and the two ceramic materials are fused through the application of laser beam, in turn creating any desired color pattern. The paper describes the influence of some physical phenomena on the progress of the laser process as well as sample experimental results.

  10. CO2 lasers and applications; Proceedings of the Meeting, Los Angeles, CA, Jan. 17, 18, 1989

    NASA Astrophysics Data System (ADS)

    Evans, James D.; Locke, Edward V.

    Recent advances in CO2 laser technology are discussed in reviews and reports. Topics examined include gain and power predictions, the discharge and output characteristics of a CW CO2 laser with auxiliary glow-dc discharge, wave-optics codes for the design and diagnostics of CO2 optical systems, military applications of CO2 waveguide lasers, and chirp measurements on a 10-J pulsed CO2 oscillator. Consideration is given to CO2 laser gain and energy extraction using C-12 and C-13 isotopes, laser-beam command guidance, gas-jet effects on laser cutting, and a galvanometric scanner for rapid tuning of CO2 lasers. Diagrams, drawings, graphs, and photographs are provided.

  11. Watt-level red-emitting diode lasers and modules for display applications

    NASA Astrophysics Data System (ADS)

    Paschke, Katrin; Blume, Gunnar; Feise, David; Pohl, Johannes; Sumpf, Bernd

    2016-02-01

    Red-emitting lasers for display applications require high output powers and a high visibility. We demonstrate diode lasers and modules in the red spectral range based on AlGaInP with optical output powers up to 1 W and a nearly diffraction limited beam. These high-luminance light sources based on tapered lasers are well suited for laser TVs and projectors for virtual reality simulators based on the flying spot technology. Additionally, we developed diode lasers with internal distributed Bragg reflector (DBR) surface gratings. These DBR tapered lasers and master-oscillator power-amplifiers based on DBR ridge-waveguide lasers and tapered amplifiers feature high power, single mode emission with coherence lengths up to several meters, which are suitable for the next-generation 3D displays based on holography.

  12. Laser flash effects on chromatic discrimination in monkeys. Final report, April 1986-June 1987

    SciTech Connect

    Schmeisser, E.T.

    1987-10-01

    Detecting a camouflaged target in a visually noisy background depends on the ability of the observer to discriminate the target from the surrounding terrain. Visible laser irradiation at less than damage levels can act as a masking source by compromising or reducing the observer's ability to resolve differences in the visual scene. Previous research has examined this concept by investigating laser flash effects on: acuity (size discrimination); tracking (motion discrimination); visual sensitivity (color); and contrast sensitivity functions (luminance contrast). In all cases, flashes from continuous-wave (CW) sources have proven more effective visually than pulsed (Q-switched) sources, when compared on peak-energy criteria (i.e., MPE), even though Q-switched lasers induce damage at lower energy doses. Additionally, the inherent safety of ultra-short laser pulses has been questioned. Past animal research has shown that, on the measures of acuity, sensitivity, tracking, and contrast detection, the animals recover to baseline if the exposure has remained below the MPE. The one measure that has not been investigated is color discrimination. The major conclusions from this investigation are: (a) red and green colored laser flashes shift the color balance transiently in the visual system, and yellow flashes do so to a lesser extent; thus targets may change both hue and brightness after an observer receives colored flashes; and (b) Q-switched lasers, at non-lesioning levels, when equated for time-averaged perceptual brightness, have comparable effects to flashes with longer time courses.

  13. Ultrafast Laser-Based Spectroscopy and Sensing: Applications in LIBS, CARS, and THz Spectroscopy

    PubMed Central

    Leahy-Hoppa, Megan R.; Miragliotta, Joseph; Osiander, Robert; Burnett, Jennifer; Dikmelik, Yamac; McEnnis, Caroline; Spicer, James B.

    2010-01-01

    Ultrafast pulsed lasers find application in a range of spectroscopy and sensing techniques including laser induced breakdown spectroscopy (LIBS), coherent Raman spectroscopy, and terahertz (THz) spectroscopy. Whether based on absorption or emission processes, the characteristics of these techniques are heavily influenced by the use of ultrafast pulses in the signal generation process. Depending on the energy of the pulses used, the essential laser interaction process can primarily involve lattice vibrations, molecular rotations, or a combination of excited states produced by laser heating. While some of these techniques are currently confined to sensing at close ranges, others can be implemented for remote spectroscopic sensing owing principally to the laser pulse duration. We present a review of ultrafast laser-based spectroscopy techniques and discuss the use of these techniques to current and potential chemical and environmental sensing applications. PMID:22399883

  14. Space Solar Power Technology Demonstration for Lunar Polar Applications: Laser-Photovoltaic Wireless Power Transmission

    NASA Technical Reports Server (NTRS)

    Henley, M. W.; Fikes, J. C.; Howell, J.; Mankins, J. C.; Howell, Joe T. (Technical Monitor)

    2002-01-01

    Space Solar Power technology offers unique benefits for near-term NASA space science missions, which can mature this technology for other future applications. "Laser-Photo-Voltaic Wireless Power Transmission" (Laser-PV WPT) is a technology that uses a laser to beam power to a photovoltaic receiver, which converts the laser's light into electricity. Future Laser-PV WPT systems may beam power from Earth to satellites or large Space Solar Power satellites may beam power to Earth, perhaps supplementing terrestrial solar photo-voltaic receivers. In a near-term scientific mission to the moon, Laser-PV WPT can enable robotic operations in permanently shadowed lunar polar craters, which may contain ice. Ground-based technology demonstrations are proceeding, to mature the technology for this initial application, in the moon's polar regions.

  15. 7th International Symposium on Applications of Laser Techniques to Fluid Mechanics, volume 1

    NASA Astrophysics Data System (ADS)

    1994-07-01

    The proceedings volumes 1 and 2 comprise the papers that were accepted for presentation at the Seventh International Symposium on Applications of Laser Techniques to Fluid Mechanics held at The Calouste Gulbenkian Foundation in Lisbon, during the period of July 11 to 14, 1994. The prime objective of this Seventh Symposium is to provide a forum for the presentation of the most advanced research on laser techniques for flow measurements, and reveal significant results to fluid mechanics. The applications of laser techniques to scientific and engineering fluid flow research is emphasized, but contributions to the theory and practice of laser methods are also considered where they facilitate new improved fluid mechanics research. Attention is focused on laser-Doppler anemometry, particle sizing and other methods for the measurement of velocity and scalars such as particle image velocimetry and laser induced fluorescence.

  16. 7th International Symposium on Applications of Laser Techniques to Fluid Mechanics, volume 2

    NASA Astrophysics Data System (ADS)

    1994-07-01

    The proceedings volumes 1 and 2 comprise the papers that were accepted for presentation at the Seventh International Symposium on Applications of Laser Techniques to Fluid Mechanics held at The Calouste Gulbenkian Foundation in Lisbon, during the period of July 11 to 14, 1994. The prime objective of this Seventh Symposium is to provide a forum for the presentation of the most advanced research on laser techniques for flow measurements, and reveal significant results to fluid mechanics. The applications of laser techniques to scientific and engineering fluid flow research is emphasized, but contributions to the theory and practice of laser methods are also considered where they facilitate new improved fluid mechanic research. Attention is focused on laser-Doppler anemometry, particle sizing and other methods for the measurement of velocity and scalars such as particle image velocimetry and laser induced fluorescence.

  17. Overview of laser applications: the state of the art and the future trend

    NASA Astrophysics Data System (ADS)

    Phipps, Claude R.

    2003-02-01

    The range and maturity of commercially useful laser applications are illustrated by selected examples. Macroscopic applications (commercialized or potentially so in the near future) include cutting, machining and welding metals, cutting fabrics, shock hardening of steels, nitrogenization of iron, and laser drilling through rock. Microscopic applications include drilling micro-holes for cooling of jet engine turbine blades, thin film growth, precision machining of structures inside transparent materials and inertially-confined deuterium-tritium fusion. To be commercially useful, these applications take advantage of the special properties of laser light, such as monochromaticity, high brightness, high pulse energy or intensity, wavelength range from soft xray to far infrared and pulse duration from femtoseconds to CW. This talk will be divided into three sections: (a) summary of the theory of laser-materials interactions with examples from published laser impulse production studies, (b) macroscopic applications, (c) microscopic applications and (d) exotic and futuristic applications, including a diode-laser-driven μN thruster for micro- and nano-satellites, and proposals to use lasers to clean hundreds of thousands of small but hazardous space debris from near-Earth space and to launch 5kg payloads into near-Earth orbit.

  18. Development of Trivalent Ytterbium Doped Fluorapatites for Diode-Pumped Laser Applications

    SciTech Connect

    Bayramian, A.J.

    2000-06-21

    One of the major motivators of this work is the Mercury Project, which is a 1 kW scalable diode-pumped solid-state laser system under development at Lawrence Livermore National Laboratory (LLNL). Major goals include 100 J pulses, 10% wallplug efficiency, 10 Hz repetition rate, and a 5 times diffraction limited beam. To achieve these goals the Mercury laser incorporates ytterbium doped Sr{sub 5}(PO{sub 4}){sub 3}F (S-FAP) as the amplifier gain medium. The primary focus of this thesis is a full understanding of the properties of this material which are necessary for proper design and modeling of the system. Ytterbium doped fluorapatites, which were previously investigated at LLNL, were found to be ideal candidate materials for a high power amplifier systems providing high absorption and emission cross sections, long radiative lifetimes, and high efficiency. A family of barium substituted S-FAP crystals were grown in an effort to modify the pump and emission bandwidths for application to broadband diode pumping and short pulse generation. Crystals of Yb{sup 3+}:Sr{sub 5-x}Ba{sub x}(PO{sub 4}){sub 3}F where x < 1 showed homogeneous lines offering 8.4 nm (1.8 times enhancement) of absorption bandwidth and 6.9 nm (1.4 times enhancement) of emission bandwidth. The gain saturation fluence of Yb:S-FAP was measured to be 3.2 J/cm{sup 2} using a pump-probe experiment where the probe laser was a high intensity Q-switched master oscillator power amplifier system. The extraction data was successfully fit to a homogeneous extraction model. The crystal quality of Czochralski grown Yb:S-FAP crystals, which have been plagued by many defects such as cracking, cloudiness, bubble core, slip dislocations, and anomalous absorption, was investigated interferometrically and quantified by means of Power Spectral Density (PSD) plots. The very best crystals grown to date were found to have adequate crystal quality for use in the Mercury laser system. In addition to phase distortions which are

  19. Laser induced micro-photoluminescence of marble and application to authenticity testing of ancient objects

    NASA Astrophysics Data System (ADS)

    Polikreti, K.; Christofides, C.

    2008-02-01

    For the last 70 years, the authenticity of disputable marble objects has been tested by using a black light lamp. According to empirical observations “fresh marbles are purple while ancient ones are blue under the lamp”. This discrimination lacks scientific basis but is very popular because sculptured stone dating is impossible. This work aims to test the reliability of the “UV method” by studying the laser excited photoluminescence (PL) of marble surfaces. An argon ion laser beam was focused through a microscope objective onto the sample, offering a PL spatial resolution of 3 μm. Newly-cut marbles show an intense emission at 610 nm ascribed to Mn2+ and a less intense one at 390 nm. Excavated surfaces show the 610 nm emission and a broadband (380-530 nm) one. Similar broadband emissions due to humic (HAs) and fulvic acids (FAs) are typical in soil PL spectra and were observed in the spectra of samples taken from the soil surrounding the excavated surfaces. Additionally, electron paramagnetic resonance (EPR) spectra of excavated surfaces show a peak at g=2.0045, typical in calcite doped with humic acids. We presume that the 380-550 nm emission originates from HA and FA salts existing in the infiltrated soil or the recrystallised calcite developed in marble patinas. Finally, the application of the “UV method” on twelve ancient and modern surfaces proved that the technique is only partly reliable and should be used together with other analytical techniques.

  20. Application of Novel CO2 Laser-Suction Device.

    PubMed

    Straus, David; Moftakhar, Roham; Fink, Yoel; Patel, Deval; Byrne, Richard W

    2013-12-01

    Background Development of the flexible CO2 fiber has presented new opportunities for the use of precision laser cutting in cranial procedures. The efficacy of the CO2 scalpel is further enhanced by combining it with a fluid removal suction capability. Objectives We report our experience with a novel CO2 laser-suction device. Methods The novel laser-suction device was designed in conjunction with OmniGuide Inc. (Cambridge, Massachusetts, USA). We performed a case review of its use in firm tumors that were resistant to resection by bipolar, suction, and ultrasonic aspirator. Results The laser-suction device was applied in three tumors where resection with ultrasonic aspiration failed. Tumor resection using the laser-suction device was successful in all three cases. There were no complications related to the laser-suction device. There were no instances of intraoperative device malfunction. Discussion The CO2 laser combined with suction is a useful instrument for resection of firm tumors that prove to be resistant to ultrasonic aspiration. We also find it to be useful in settings where precise tissue incisions are desired with minimal manipulation. In our experience, the surgical efficiency of the CO2 laser is improved by the laser-suction device. This device allows the surgeon to utilize a suction device and laser in a single hand and enables concurrent use of bipolar electrocautery without repeated instrument changes.

  1. Laser applications to chemical analysis: an introduction by the feature editors

    NASA Astrophysics Data System (ADS)

    Jeffries, Jay B.; Ramsey, J. Michael; Lucht, Robert P.

    1995-06-01

    This issue of Applied Optics features papers on the application of laser technology to chemical analysis. Many of the contributions, although not all, result from papers presented at the Fourth OSA Topical Meeting on Laser Applications to Chemical Analysis, which was held at Jackson Hole, Wyoming, March, 1994. This successful meeting, with nearly one hundred participants, continued the tradition of earlier LACA meetings to focus on the optical science of laser-based measurements of temperature and trace chemical assays in a wide variety of practical applications.

  2. Industrial fiber beam delivery system for ultrafast lasers: applications and recent advances

    NASA Astrophysics Data System (ADS)

    Eilzer, Sebastian; Funck, Max C.; Wedel, Björn

    2016-03-01

    Fiber based laser beam delivery is the method of choice for high power laser applications whenever great flexibility is required. For cw-lasers fiber beam delivery has long been established but has recently also become available for ultrafast lasers. Using micro-structured hollow core fibers that guide the laser beam mostly inside a hollow core, nonlinear effects and catastrophic damage that arise in conventional glass fibers can be avoided. Today, ultrafast pulses with several 100 μJ and hundreds of MW can be transmitted in quasi single mode fashion. In addition, the technology opens new possibilities for beam delivery systems as the pulse propagation inside the fiber can be altered on purpose. For example to shorten the pulse duration of picosecond lasers down into the femtosecond regime. We present a modular fiber beam delivery system for micromachining applications with industrial pico- and femtosecond lasers that is flexibly integrated into existing applications. Micro-structured hollow core fibers inside the sealed laser light cable efficiently guide high-power laser pulses over distances of several meters with excellent beam quality, while power, pulse duration and polarization are maintained. Robust and stable beam transport during dynamic operation as in robot or gantry systems will be discussed together with optional pulse compression.

  3. Development of trivalent ytterbium doped fluorapatites for diode-pumped laser applications

    NASA Astrophysics Data System (ADS)

    Bayramian, Andrew James

    2000-11-01

    A major motivator of this work is the Mercury Project, a one kilowatt diode-pumped solid-state laser system under development at Lawrence Livermore National Laboratory (LLNL), which incorporates ytterbium doped strontium fluorapatite, Sr5(PO4)3F (S-FAP), as the amplifier gain medium. The primary focus of this thesis is a full understanding of the properties of this material, which is necessary for proper design and modeling of the system. Ytterbium-doped fluorapatites were investigated at LLNL prior to this work and found to be ideal candidate materials for high-power amplifier systems providing high absorption and emission cross sections, long radiative lifetimes, and high efficiency. A family of barium substituted S-FAP crystals was grown in an effort to modify the pump and emission bandwidths for application to broadband diode pumping and short pulse generation. Crystals of Yb 3+:Srs5-xBax(PO4) 3F where x < 1 showed homogeneous lines offering 8.4 nm (1.8X enhancement) of absorption bandwidth and 6.9 nm (1.4X enhancement) of emission bandwidth. The gain saturation fluence of Yb:S-FAP was measured to be 3.2 J/cm 2 with homogeneous extraction using a pump-probe experiment where the probe laser was a high intensity Q-switched master oscillator power amplifier system. The crystal quality of Czochralski grown Yb:S-FAP boules, which is effected by defects such as cracking, cloudiness, bubble core, slip dislocations, and anomalous absorption, was investigated interferometrically and quantified by means of Power Spectral Density (PSD) plots. Stimulated Raman Scattering (SRS) losses were evaluated by first measuring the SRS gain coefficient to be 1.3 cm/GW, then modeling the losses in the Mercury amplifier system. Countermeasures including the addition of bandwidth to the extraction beam and wedging of amplifier surfaces are shown to reduce the SRS losses allowing efficient laser gain extraction at higher intensities. Finally, an efficient Q-switched Yb:S-FAP oscillator

  4. Activity of retinal ganglion cells following intense, nanosecond laser flashes. Final report, 1983-1986

    SciTech Connect

    Glickman, R.D.

    1989-01-01

    The effects of intense, but nonlesion-producing, laser exposures of 20-ns duration were determined on the light responses and spontaneous activity of retinal ganglion cells recorded in situ from the rhesus monkey. (Following a single, 20-ns exposure centered on its receptive field, a ganglion cell produced an 'afterdischarge' of maintained action potentials). The duration of the afterdischarge depended on the diameter of the laser beam on the retina and on the beam's intensity. Laser exposures subtending 0.5 to 2.0 deg, and delivering 45 to 60% of the maximum permissible exposure, elicited afterdischarges that lasted up to 80 s. When the beam diameter was decreased to 0.25 deg, the afterdischarge was reduced to 30 s, and to less than 5 s with the 0.12-deg beam. Light sensitivity after the laser exposure recovered rapidly during the first 10 s and then more slowly, but exponentially, until it reached the preflash level. Color-opponent ganglion cells exhibited a phenomenon called 'response-reversal' after the laser exposure, presumably due to selective adaptation of a mid-wavelength cone-input. Because a 20-ns exposure, regardless of intensity, is likely to photoregenerate more than half of the available visual pigment, the effects of ganglion cell response described here are not likely to be due solely to pigment bleaching.

  5. Coagulative and ablative characteristics of a novel diode laser system (1470nm) for endonasal applications

    NASA Astrophysics Data System (ADS)

    Betz, C. S.; Havel, M.; Janda, P.; Leunig, A.; Sroka, R.

    2008-02-01

    Introduction: Being practical, efficient and inexpensive, fibre guided diode laser systems are preferable over others for endonasal applications. A new medical 1470 nm diode laser system is expected to offer good ablative and coagulative tissue effects. Methods: The new 1470 nm diode laser system was compared to a conventional 940 nm system with regards to laser tissue effects (ablation, coagulation, carbonization zones) in an ex vivo setup using fresh liver and muscle tissue. The laser fibres were fixed to a computer controlled stepper motor, and the light was applied using comparable power settings and a reproducible procedure under constant conditions. Clinical efficacy and postoperative morbidity was evaluated in two groups of 10 patients undergoing laser coagulation therapy of hyperplastic nasal turbinates. Results: In the experimental setup, the 1470 nm laser diode system proved to be more efficient in inducing tissue effects with an energy factor of 2-3 for highly perfused hepatic tissue to 30 for muscular tissue. In the clinical case series, the higher efficacy of the 1470 nm diode laser system led to reduced energy settings as compared to the conventional system with comparable clinical results. Postoperative crusting was less pronounced in the 1470 nm laser group. Conclusion: The 1470 nm diode laser system offers a highly efficient alternative to conventional diode laser systems for the coagulation of hyperplastic nasal turbinates. According to the experimental results it can be furthermore expected that it disposes of an excellent surgical potential with regards to its cutting abilities.

  6. Laser lithotripsy: a review of 20 years of research and clinical applications.

    PubMed

    Dretler, S P

    1988-01-01

    Four new technologies have transformed the treatment of urinary calculi: electrohydraulic lithotripsy, ultrasonic lithotripsy, extracorporeal shock wave lithotripsy, and laser lithotripsy. Initial attempts to ablate urinary calculi by continuous wave CO2, ruby, and Nd-YAG lasers failed because of excess thermal injury and inability to pass the laser energy via a flexible fiber. Basic laboratory studies then demonstrated that short pulsed laser energy absorbed by the calculus resulted in fragmentation. The parameters that produced optimal urinary calculus fragmentation were found using the flashlamp pumped tunable dye laser, with the following parameters: wavelength: 504 nm; pulse duration: 1 microsec; fiber: 250 micro silica-coated quartz; repetition: 5-20 Hz. Use of pulsed dye laser caused no tissue damage. The mechanism of fragmentation is light absorption, plasma development, and repetitive acoustic shock wave action with resultant fragmentation. The techniques for application of laser to calculi have been successful, and new, miniature instruments have been developed. Laser lithotripsy is a successful method for fragmenting ureteral calculi. The small caliber of the laser fiber makes this method useful for treating calculi in narrow, tortuous ureters; impacted calculi; distal calculi in ureters that cannot be dilated, via the percutaneous route for stones in calyces or impacted in the upper ureter. Investigations are continuing to optimize fragmentation of harder calculi and to use laser fragmentation within the kidney. Laser lithotripsy may also be used to fragment biliary calculi.

  7. Topical laser application enhances enamel fluoride uptake and tribological properties.

    PubMed

    Jeng, Y-R; Lin, T-T; Huang, J-S; Peng, S-R; Shieh, D-B

    2013-07-01

    Topical fluoride treatment prevents dental caries. However, the resulting calcium-fluoride-like deposits are soft and have poor wear resistance; therefore, frequent treatment is required. Lasers quickly heat surfaces and can be made portable and suitable for oral remedies. We examined the morphology, nanohardness, elastic modulus, nanowear, and fluoride uptake of fluoride-treated enamel followed by CO2 laser irradiation for 5 and 10 sec, respectively. We found that laser treatments significantly increased the mechanical properties of the calcium-fluoride-like deposits. The wear resistance of the calcium-fluoride-like deposits improved about 34% after laser irradiation for 5 sec and about 40% following irradiation for 10 sec. We also found that laser treatments increased fluoride uptake by at least 23%. Overall, laser treatment significantly improved fluoride incorporation into dental tissue and the wear resistance of the protective calcium-fluoride layer.

  8. LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Optical velocimeter based on a semiconductor laser

    NASA Astrophysics Data System (ADS)

    Belousov, P. Ya; Dubnishchev, Yu N.; Meledin, V. G.

    1988-03-01

    It is shown that optical velocimeters using diffraction beam splitters are not critically sensitive to the stability of the emission wavelength of a semiconductor laser. A functional scheme of a semiconductor laser source with systems for stabilization of the temperature and pump current is described. The technical characteristics are given of a semiconductor-laser velocimeter for the determination of the velocity and length of rolling stock.

  9. Understanding lasers

    SciTech Connect

    Gibilisco, S.

    1989-01-01

    Covering all different types of laser applications-Gibilisco offers an overview of this fascinating phenomenon of light. Here he describes what lasers are and how they work and examines in detail the different kinds of lasers in use today. Topics of particular interest include: the way lasers work; the different kinds of lasers; infrared, ultraviolet and x-ray lasers; use of lasers in industry and manufacturing; use of lasers for long-distance communications; fiberoptic communications; the way laser shows work; the reality of Star Wars; lasers in surgical and medical applications; and holography and the future of laser technology.

  10. Application of unstable resonators for copper-vapor lasers

    SciTech Connect

    Liang Baogen; Yin Xianhua

    1987-07-01

    An analysis is made of the possibility of using unstable resonators in reducing the divergence of radiation from a high-gain, short inversion lifetime copper vapor laser. The output laser beam characteristics of telescopic resonators are compared with those of plane-concave resonators. It is shown that to obtain an output beam with low divergence in such a laser, unstable resonators must be used.

  11. Diode pumped alkali vapor lasers for high power applications

    NASA Astrophysics Data System (ADS)

    Zweiback, J.; Krupke, B.; Komashko, A.

    2008-02-01

    General Atomics has been engaged in the development of diode pumped alkali vapor lasers. We have been examining the design space looking for designs that are both efficient and easily scalable to high powers. Computationally, we have looked at the effect of pump bandwidth on laser performance. We have also looked at different lasing species. We have used an alexandrite laser to study the relative merits of different designs. We report on the results of our experimental and computational studies.

  12. Potential biomedical application of the Los Alamos infrared free-electron laser: DNA spectroscopy

    NASA Astrophysics Data System (ADS)

    Lumpkin, A. H.; Trewhella, J.; Garcia, A. E.

    Recently, the Los Alamos Free-Electron Laser has demonstrated optical output at wavelengths from 9 to 45 microns. Potential application of such a laser are proposed for the study of vibrational modes predicted in different conformations of DNA and in DNA complexed with drugs and/or proteins that regulate replication and/or transcription.

  13. Applications using a Picosecond 14.7 nm X-Ray Laser

    SciTech Connect

    Dunn, J; Smith, R F; Nilsen, J; Shlyaptsev, V N; Filevich, J; Rocca, J J; Marconi, M C

    2001-09-21

    We report recent application experiments on the LLNL COMET tabletop facility using the picosecond, 14.7 nm Ni-like Pd x-ray laser. This work includes measurements of a laser-produced plasma density profile with a diffraction grating interferometer.

  14. Application of laser velocimetry to unsteady flows in large scale high speed tunnels

    NASA Technical Reports Server (NTRS)

    Owen, F. K.

    1983-01-01

    Flowfield measurements obtained in several large scale, high speed facilities are presented. Sampling bias and seeding problems are addressed and solutions are outlined. The laser velocimeter systems and data reduction procedures which were used in the experiments are also described. The work demonstrated the potential of the laser velocimeter for applications in other than closely controlled, smallscale laboratory situations.

  15. Birefringence of solid-state laser media: broadband tuning discontinuities and application to laser line narrowing

    SciTech Connect

    Krasinski, J.S.; Band, Y.B.; Chin, T.; Heller, D.F.; Morris, R.C.; Papanestor, P.

    1989-04-15

    Spectral consequences that result from using birefringent media with broadband gain inside of laser cavities containing polarizing elements are described. We show that the laser intensity is modulated as a function of the output frequency unless the cavity elements are carefully aligned so that their polarization axis coincides with a principal optical axis of the gain medium. Analysis of the tuning characteristics of a birefringent polarization-dependent gain medium is exploited to provide a simple method for line narrowing the laser output. By introduction of an intracavity birefringent compensator the narrow-band output can be continuously tuned. Experimental results for alexandrite lasers are presented.

  16. Induced Current Characteristics Due to Laser Induced Plasma and Its Application to Laser Processing Monitoring

    SciTech Connect

    Madjid, Syahrun Nur; Idris, Nasrullah; Kurniawan, Koo Hendrik

    2011-03-30

    In laser processing, suitable conditions for laser and gas play important role in ensuring a high quality of processing. To determine suitable conditions, we employed the electromagnetic phenomena associated with laser plasma generation. An electrode circuit was utilised to detect induced current due to the fast electrons propelled from the material during laser material processing. The characteristics of induced current were examined by changing parameters such as supplied voltage, laser pulse energy, number of laser shots, and type of ambient gas. These characteristics were compared with the optical emission characteristics. It was shown that the induced current technique proposed in this study is much more sensitive than the optical method in monitoring laser processing, that is to determine the precise focusing condition, and to accurately determine the moment of completion of laser beam penetration. In this study it was also shown that the induced current technique induced by CW CO{sub 2} laser can be applied in industrial material processing for monitoring the penetration completion in a stainless steel plate drilling process.

  17. Laser-based ion sources for medical applications

    NASA Astrophysics Data System (ADS)

    Bychenkov, V. Yu.; Brantov, A. V.

    2015-10-01

    Interaction of relativistic short laser pulses with thin foils is studied by using 3D PIC simulations in the context of ICAN's "dream laser". It is shown that such a laser will make it possible to accelerate protons and deuterons to multi-MeV energies with a current density of 100 A/cm2. The laser-triggered hadron beams may trigger nuclear reactions of interest for nuclear medicine and pharmacy. As an example, the yields C-11 for PET, of Tc-99m for SPECT, and neutrons for therapy have been analyzed.

  18. Laser photovoltaic power system synergy for SEI applications

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Hickman, J. M.

    1991-01-01

    Solar arrays can provide reliable space power, but do not operate when there is no solar energy. Photovoltaic arrays can also convert laser energy with high efficiency. One proposal to reduce the required mass of energy storage required is to illuminate the photovoltaic arrays by a ground laser system. It is proposed to locate large lasers on cloud-free sites at one or more ground locations, and use large lenses or mirrors with adaptive optical correction to reduce the beam spread due to diffraction or atmospheric turbulence. During the eclipse periods or lunar night, the lasers illuminate the solar arrays to a level sufficient to provide operating power.

  19. Basics of Lasers: History, Physics, and Clinical Applications.

    PubMed

    Franck, Philipp; Henderson, Peter W; Rothaus, Kenneth O

    2016-07-01

    Lasers are increasingly used by plastic surgeons to address issues such as wrinkles and textural changes, skin laxity, hyperpigmentation, vascularity, and excess fat accumulation. A fundamental understanding of the underlying science and physics of laser technology is important for the safe and efficacious use of laser in medical settings. The purpose of this article was to give clinicians with limited exposure to lasers a basic understanding of the underlying science. In that manner, they can confidently make appropriate decisions as to the best device to use on a patient (or the best device to purchase for a practice).

  20. Evaluation of laser welding techniques for hydrogen transmission. Final report, September 1977-November 1979

    SciTech Connect

    Mucci, J

    1980-05-01

    This program was established to determine the feasibility of laser beam welding as a fabrication method for hydrogen transmission and is a precursor in the effort to systematically provide the technological base necessary for large-scale, economic pipeline transmission of fuel for a hydrogen energy system. The study contributes to the technology base by establishing the effect of conventional weld processes and laser beam welding on the mechanical properties of two classes of steels in an air and high pressure gaseous hydrogen environment. Screening evaluation of the tensile, low-cycle fatigue and fracture toughness properties and metallurgical analyses provide the basis for concluding that laser beam welding of AISI 304L stainless steel and ASTM A106B carbon steel can produce weldments of comparable quality to those produced by gas-tungsten arc and electron beam welding and is at least equally compatible with 13.8 MPa (2000 psig) gaseous hydrogen environment.