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Sample records for laser alignment system

  1. Nova laser alignment control system

    SciTech Connect

    Van Arsdall, P.J.; Holloway, F.W.; McGuigan, D.L.; Shelton, R.T.

    1984-03-29

    Alignment of the Nova laser requires control of hundreds of optical components in the ten beam paths. Extensive application of computer technology makes daily alignment practical. The control system is designed in a manner which provides both centralized and local manual operator controls integrated with automatic closed loop alignment. Menudriven operator consoles using high resolution color graphics displays overlaid with transport touch panels allow laser personnel to interact efficiently with the computer system. Automatic alignment is accomplished by using image analysis techniques to determine beam references points from video images acquired along the laser chain. A major goal of the design is to contribute substantially to rapid experimental turnaround and consistent alignment results. This paper describes the computer-based control structure and the software methods developed for aligning this large laser system.

  2. Laser beam alignment system

    DOEpatents

    Kasner, William H.; Racki, Daniel J.; Swenson, Clark E.

    1984-01-01

    A plurality of pivotal reflectors direct a high-power laser beam onto a workpiece, and a rotatable reflector is movable to a position wherein it intercepts the beam and deflects a major portion thereof away from its normal path, the remainder of the beam passing to the pivotal reflectors through an aperture in the rotating reflector. A plurality of targets are movable to positions intercepting the path of light traveling to the pivotal reflectors, and a preliminary adjustment of the latter is made by use of a low-power laser beam reflected from the rotating reflector, after which the same targets are used to make a final adjustment of the pivotal reflectors with the portion of the high-power laser beam passed through the rotating reflector.

  3. Vacuum mechatronic laser alignment system on the Nova laser

    SciTech Connect

    Holliday, M.; Wong, K.; Shelton, R.

    1991-11-01

    The experiments conducted on NOVA are done to investigate inertially confined laser fusion reactions. To this end, the ten beams of the laser are aligned to within 30mm. The target chamber employs a vacuum mechatronic based reticle/target positioning system to accomplish this. It is a five degree-of-freedom chamber resident system, known as the Alignment Aids Positioner or AAP. The AAP aids in beam and diagnostic alignment by accurately positioning a reticle at target chamber center to with 7mm. The AAP system increases target positioning and alignment flexibility and accuracy through the use of a computer controlled multi degree-of-freedom stage assembly. This device uses microstepping DC stepper motors with encoders to achieve closed loop control in a 10{sup {minus}6} torr vacuum. The AAP has two positioning regimes to move the alignment reticle and do beam alignment. One is course positioning in the Y-Z plane that moves a high resolution stage assembly to target chamber center. The other regime is high resolution movement in the X,Y,Z and q directions. 5 refs., 9 figs.

  4. 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.

  5. Far-field detection system for laser beams alignment and crystals alignment

    NASA Astrophysics Data System (ADS)

    Liu, D.; Qin, H.; Zhu, B.

    2015-08-01

    Laser beams far-field alignment is very important for the high power laser facility as well as the frequency doubling crystals adjustment. Traditional beams alignment system and crystals alignment system are separated. That means, they use different optical image systems and CCD cameras, which will occupy larger space and use more money. A new farfield detection system of laser beams is presented with a big diffraction grating (37mm*37mm), a set of optical imaging components and a high resolution CCD camera. This detection system, which is fully demonstrated on the National Laser Facility of Israel, can align high power laser facility beams' direction as well as the frequency doubling crystals. The new system occupies small space in the spatial filter through off-axial grating sampling. The experimental results indicate that the average far-field alignment error is less than 5% of spatial filter pinhole diameter, and the average crystals' matching angle error is less than 10urad, which meet the alignment system requirements for beams and crystals.

  6. Relay telescope for high power laser alignment system

    DOEpatents

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2006-09-19

    A laser system includes an optical path having an intracavity relay telescope with a telescope focal point for imaging an output of the gain medium between an image location at or near the gain medium and an image location at or near an output coupler for the laser system. A kinematic mount is provided within a vacuum chamber, and adapted to secure beam baffles near the telescope focal point. An access port on the vacuum chamber is adapted for allowing insertion and removal of the beam baffles. A first baffle formed using an alignment pinhole aperture is used during alignment of the laser system. A second tapered baffle replaces the alignment aperture during operation and acts as a far-field baffle in which off angle beams strike the baffle a grazing angle of incidence, reducing fluence levels at the impact areas.

  7. Alignment and diagnostics on the National Ignition Facility laser system

    SciTech Connect

    Bliss, E S; Boege, S J; Boyd, B; Demaret, R D; Feldman, M; Gates, A J; Holdener, F R; Hollis, J; Knopp, C F; McCarville, T J; Miller-Kamm; Rivera, W E; Salmon, J T; Severyn, J R; Thompson, C E; V J; Wang, D Y; Zacharias, R A

    1999-07-01

    The NIF laser system will be capable of delivering 1.8MJ of 351nm energy in 192 beams. Diagnostics instruments must measure beam energy, power vs. time, wavefront quality, and beam intensity profile to characterize laser performance. Alignment and beam diagnostics are also used to set the laser up for the high power shots and to isolate problems when performance is less than expected. Alignment and beam diagnostics are multiplexed to keep the costs under control. At the front-end the beam is aligned and diagnosed in an input sensor package. The output 1053nm beam is sampled by collecting a 0.1% reflection from an output beam sampler and directing it to the output sensor package (OSP). The OSP also gets samples from final focus lens reflection and samples from the transport spatial filter pinhole plane. The output 351nm energy is measured by a calorimeter collecting the signal from an off-axis diffractive beam-sampler. Detailed information on the focused beam in the high-energy target focal plane region is gathered in the precision diagnostics. This paper describes the design of the alignment and diagnostics on the NIF laser system.

  8. An active alignment method for post launch co-alignment of laser beam combiner systems

    NASA Technical Reports Server (NTRS)

    Yu, A. W.; Green, J. W.; Maynard, W. L.; Minott, P. O.; Krainak, M. A.

    1992-01-01

    A laser transmitter for high bandwidth geosynchronous satellite communications is described. High optical power is achieved by combining semiconductor laser diodes. An active alignment scheme is proposed for achieving the +/- 20 microrad post launch multiple laser angular co-alignment requirement.

  9. Alignment and focusing device for a multibeam laser system

    SciTech Connect

    Sweatt, W.C.

    1980-01-01

    Large inertial confinement fusion laser systems have many beams focusing on a small target. The Antares system is a 24-beam CO/sub 2/ pulse laser. To produce uniform illumination, the 24 beams must be individually focused on (or near) the target's surface in a symmetric pattern. To assess the quality of a given beam, we will locate a Smartt (point diffraction) interferometer at the desired focal point and illuminate it with an alignment laser. The resulting fringe pattern shows defocus, lateral misalignment, and beam aberrations; all of which can be minimized by tilting and translating the focusing mirror and the preceding flat mirror. The device described in this paper will remotely translate the Smartt interferometer to any position in the target space and point it in any direction using a two-axis gimbal. The fringes produced by the interferometer are relayed out of the target vacuum shell to a vidicon by a train or prisms. We are designing four separate snap-in heads to mount on the gimbal; two of which are Smartt interferometers (for 10.6 ..mu..m and 633 nm) and two for pinholes, should we wish to put an alignment beam backwards through the system.

  10. NIF pointing and centering systems and target alignment using a 351 nm laser source

    SciTech Connect

    Boege, S.J.; Bliss, E.S.; Chocol, C.J.; Holdener, F.R.; Miller, J.L.; Toeppen, J.S.; Vann, C.S.; Zacharias, R.A.

    1996-10-01

    The operational requirements of the National Ignition Facility (NIF) place tight constraints upon its alignment system. In general, the alignment system must establish and maintain the correct relationships between beam position, beam angle, laser component clear apertures, and the target. At the target, this includes adjustment of beam focus to obtain the correct spot size. This must be accomplished for all beamlines in a time consistent with planned shot rates and yet, in the front end and main laser, beam control functions cannot be initiated until the amplifiers have sufficiently cooled so as to minimize dynamic thermal distortions during and after alignment and wavefront optimization. The scope of the task dictates an automated system that implements parallel processes. We describe reticle choices and other alignment references, insertion of alignment beams, principles of operation of the Chamber Center Reference System 2048 and Target Alignment Sensor, and the anticipated alignment sequence that will occur between shots.

  11. Metrology system for inter-alignment of lasers, telescopes, and mechanical datum

    NASA Astrophysics Data System (ADS)

    Aharon, Oren; Vishnia, Itai

    2015-10-01

    In modern scientific and industrial laser applications, inter-alignment of multiple optical devices is frequently a basic requirement to meet a certain specification and performance. However, the designed optical system combining mechanical elements, lasers and optical sights in various wavelengths frequently deviates from specified goals due to real life imperfections and effects. These may include mechanical tolerances, optical distortion, heating, laser cavity misalignment, overall instabilities, and non-linear effects. In order to deliver accurately and produce intricate optical systems, a carefully designed method for inter-alignment is required completing and updating the already existing methods. Thus, we designed and upgraded the performance of electronic autocollimator and combined it with innovative mechanical manipulation of optical invariants such as a Lateral Transfer Hollow Periscope to greatly improve and expand inter-alignment procedures. Depending on the combination of optical sights, laser types, and mechanical requirements, an appropriate method will be analyzed. For example, several layouts will be analyzed such as high power CO2 laser cavity alignment and laser delivery system mechanical rollers alignment. By completing the presented gear in this article other instruments such as Align Meter, Lateral Hollow Periscope (LTHPTM), Lateral Hollow Retroreflector ( LTHRTM) are available for applications such as alignment of articulated beam delivery systems.

  12. Far-field detection system for laser beam and crystal alignment

    NASA Astrophysics Data System (ADS)

    Zhang, Jiachen; Liu, Daizhong; Zhu, Baoqiang; Tang, Shunxing; Gao, Yanqi

    2016-03-01

    Laser beam far-field alignment as well as frequency-doubling and frequency-tripling crystal adjustment is very important for high-power laser facility. Separate systems for beam and crystal alignment are generally used while the proposed approach by off-axial grating sampling share common optics for these two functions, reducing both space and cost requirements. This detection system has been demonstrated on the National Laser Facility of Israel. The experimental results indicate that the average far-field alignment error is <5% of the spatial filter pinhole diameter, average autocollimation angle error of crystals is <10 μrad, and average frequency-tripling conversion efficiency is 69.3%, which meet the alignment system requirements on the beam direction and crystals.

  13. Using Stars to Align a Steered Laser System for Cosmic Ray Simulation

    NASA Astrophysics Data System (ADS)

    Krantz, Harry; Wiencke, Lawrence

    2016-03-01

    Ultra high energy cosmic rays (UHECRs) are the highest energy cosmic particles with kinetic energy above 1018eV . UHECRs are detected from the air shower of secondary particles and UV florescence that results from interaction with the atmosphere. A high power UV laser beam can be used to simulate the optical signature of a UHCER air shower. The Global Light System (GLS) is a planned network of ground-based light sources including lasers to support the planned space-based Extreme Universe Space Observatory (EUSO). A portable prototype GLS laser station has been constructed at the Colorado School of Mines. Currently the laser system uses reference targets on the ground but stars can be used to better align the beam by providing a complete hemisphere of targets. In this work, a CCD camera is used to capture images of known stars through the steering head optics. The images are analyzed to find the steering head coordinates of the target star. The true coordinates of the star are calculated from the location and time of observation. A universal adjustment for the steering head is determined from the differences between the two pairs of coordinates across multiple stars. This laser system prototype will also be used for preflight tests of the ESUO Super Pressure Balloon mission.

  14. Laser beam alignment apparatus and method

    DOEpatents

    Gruhn, Charles R.; Hammond, Robert B.

    1981-01-01

    The disclosure relates to an apparatus and method for laser beam alignment. Thermoelectric properties of a disc in a laser beam path are used to provide an indication of beam alignment and/or automatic laser alignment.

  15. Laser beam alignment apparatus and method

    DOEpatents

    Gruhn, C.R.; Hammond, R.B.

    The disclosure related to an apparatus and method for laser beam alignment. Thermoelectric properties of a disc in a laser beam path are used to provide an indication of beam alignment and/or automatic laser alignment.

  16. Laser-Beam-Alignment Controller

    NASA Technical Reports Server (NTRS)

    Krasowski, M. J.; Dickens, D. E.

    1995-01-01

    In laser-beam-alignment controller, images from video camera compared to reference patterns by fuzzy-logic pattern comparator. Results processed by fuzzy-logic microcontroller, which sends control signals to motor driver adjusting lens and pinhole in spatial filter.

  17. Novel planar laser encoder system for two-dimensional positioning with ultrahigh head-to-scale alignment tolerance

    NASA Astrophysics Data System (ADS)

    Wu, Chyan-Chyi; Chang, Calvin C.; Kao, Ching-Fen; Peng, Gwo-Sheng

    2003-11-01

    Laser encoders overcome the fundamental resolution limit of geometrical optical encoders by cleverly converting the diffraction limit to phase coded information so as to facilitate nanometer displacement measurement. As positioning information is coded within the optical wavefront of laser encoders, interferometry principles must be adopted in the design of the laser encoders. This effect has posed a very strong alignment tolerance among various components of the whole laser encoder, which in turn imposes a serious user adaptation bottleneck. Out of all alignment tolerances, the head-to-scale alignment tolerance represents the most important hindrance for wider ap-plications. This paper presents a novel laser planar encoder, which serves as a two-dimensional position detection apparatus for precision machine applications and can provide a measuring resolution less than 1 nm. Improving the IBM laser optical encoder design by taking into consideration manufacturing tolerance of various optical components, an innovative two-dimensional laser encoder with ultra high head-to-scale tolerance is presented. It was identified that this newly proposed laser encoder design could avoid the effect of differences in polarization diffraction efficiencies for the 2-D grating scale used. Optimizing the system performance by cleverly designing the profile of the 2-D grating scale was also detailed. The effect of non-uniform temperature field within the head-to-scale range that can yield a nonzero initial phase so as to decrease the system measurement accuracy was analyzed. In addition, misalignment of the polarizers located in front the photodiodes were identified to be the main cause for imperfect Lissajous circles, which may lower the measuring resolution when traditional arctangent algorithm was adopted for circular polarization interferometers. The resolution of the newly developed laser planar encoder was verified by experiments and was found to agree well with the theoretical

  18. Neural-network-directed alignment of optical systems using the laser-beam spatial filter as an example

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.; Krasowski, Michael J.; Weiland, Kenneth E.

    1993-01-01

    This report describes an effort at NASA Lewis Research Center to use artificial neural networks to automate the alignment and control of optical measurement systems. Specifically, it addresses the use of commercially available neural network software and hardware to direct alignments of the common laser-beam-smoothing spatial filter. The report presents a general approach for designing alignment records and combining these into training sets to teach optical alignment functions to neural networks and discusses the use of these training sets to train several types of neural networks. Neural network configurations used include the adaptive resonance network, the back-propagation-trained network, and the counter-propagation network. This work shows that neural networks can be used to produce robust sequencers. These sequencers can learn by example to execute the step-by-step procedures of optical alignment and also can learn adaptively to correct for environmentally induced misalignment. The long-range objective is to use neural networks to automate the alignment and operation of optical measurement systems in remote, harsh, or dangerous aerospace environments. This work also shows that when neural networks are trained by a human operator, training sets should be recorded, training should be executed, and testing should be done in a manner that does not depend on intellectual judgments of the human operator.

  19. Antares beam-alignment-system performance

    SciTech Connect

    Appert, Q.D.; Bender, S.C.

    1983-01-01

    The beam alignment system for the 24-beam-sector Antares CO/sub 2/ fusion laser automatically aligns more than 200 optical elements. A visible-wavelength alignment technique is employed which uses a telescope/TV system to view point-light sources appropriately located down the beamline. The centroids of the light spots are determined by a video tracker, which generates error signals used by the computer control system to move appropriate mirrors in a closed-loop system. Final touch-up alignment is accomplished by projecting a CO/sub 2/ alignment laser beam through the system and sensing its position at the target location. The techniques and control algorithms employed have resulted in alignment accuracies exceeding design requirements. By employing video processing to determine the centroids of diffraction images and by averaging over multiple TV frames, we achieve alignment accuracies better than 0.1 times system diffraction limits in the presence of air turbulence.

  20. Magnetic alignment and the Poisson alignment reference system

    NASA Astrophysics Data System (ADS)

    Griffith, L. V.; Schenz, R. F.; Sommargren, G. E.

    1990-08-01

    Three distinct metrological operations are necessary to align a free-electron laser (FEL): the magnetic axis must be located, a straight line reference (SLR) must be generated, and the magnetic axis must be related to the SLR. This article begins with a review of the motivation for developing an alignment system that will assure better than 100-μm accuracy in the alignment of the magnetic axis throughout an FEL. The 100-μm accuracy is an error circle about an ideal axis for 300 m or more. The article describes techniques for identifying the magnetic axes of solenoids, quadrupoles, and wiggler poles. Propagation of a laser beam is described to the extent of revealing sources of nonlinearity in the beam. Development of a straight-line reference based on the Poisson line, a diffraction effect, is described in detail. Spheres in a large-diameter laser beam create Poisson lines and thus provide a necessary mechanism for gauging between the magnetic axis and the SLR. Procedures for installing FEL components and calibrating alignment fiducials to the magnetic axes of the components are also described. The Poisson alignment reference system should be accurate to 25 μm over 300 m, which is believed to be a factor-of-4 improvement over earlier techniques. An error budget shows that only 25% of the total budgeted tolerance is used for the alignment reference system, so the remaining tolerances should fall within the allowable range for FEL alignment.

  1. Magnetic axis alignment and the Poisson alignment reference system

    NASA Astrophysics Data System (ADS)

    Griffith, Lee V.; Schenz, Richard F.; Sommargren, Gary E.

    1989-01-01

    Three distinct metrological operations are necessary to align a free-electron laser (FEL): the magnetic axis must be located, a straight line reference (SLR) must be generated, and the magnetic axis must be related to the SLR. This paper begins with a review of the motivation for developing an alignment system that will assure better than 100 micrometer accuracy in the alignment of the magnetic axis throughout an FEL. The paper describes techniques for identifying the magnetic axis of solenoids, quadrupoles, and wiggler poles. Propagation of a laser beam is described to the extent of revealing sources of nonlinearity in the beam. Development and use of the Poisson line, a diffraction effect, is described in detail. Spheres in a large-diameter laser beam create Poisson lines and thus provide a necessary mechanism for gauging between the magnetic axis and the SLR. Procedures for installing FEL components and calibrating alignment fiducials to the magnetic axes of the components are also described. An error budget shows that the Poisson alignment reference system will make it possible to meet the alignment tolerances for an FEL.

  2. Segment alignment control system

    NASA Technical Reports Server (NTRS)

    Aubrun, JEAN-N.; Lorell, Ken R.

    1988-01-01

    The segmented primary mirror for the LDR will require a special segment alignment control system to precisely control the orientation of each of the segments so that the resulting composite reflector behaves like a monolith. The W.M. Keck Ten Meter Telescope will utilize a primary mirror made up of 36 actively controlled segments. Thus the primary mirror and its segment alignment control system are directly analogous to the LDR. The problems of controlling the segments in the face of disturbances and control/structures interaction, as analyzed for the TMT, are virtually identical to those for the LDR. The two systems are briefly compared.

  3. Alignment microscope for rotating laser scanner

    NASA Technical Reports Server (NTRS)

    Maciel, A., Jr.; Beck, J. C.

    1972-01-01

    Microscopic assembly for alignment of rotary laser focuses on small film area along scan line at oblique angle. Suitable choice of angle and location of optical components project laser beam line as X coordinate reticle. Coordination with horizontal recticle line included microscope facilitates Y coordinate position indexing.

  4. Automatic alignment of double optical paths in excimer laser amplifier

    NASA Astrophysics Data System (ADS)

    Wang, Dahui; Zhao, Xueqing; Hua, Hengqi; Zhang, Yongsheng; Hu, Yun; Yi, Aiping; Zhao, Jun

    2013-05-01

    A kind of beam automatic alignment method used for double paths amplification in the electron pumped excimer laser system is demonstrated. In this way, the beams from the amplifiers can be transferred along the designated direction and accordingly irradiate on the target with high stabilization and accuracy. However, owing to nonexistence of natural alignment references in excimer laser amplifiers, two cross-hairs structure is used to align the beams. Here, one crosshair put into the input beam is regarded as the near-field reference while the other put into output beam is regarded as the far-field reference. The two cross-hairs are transmitted onto Charge Coupled Devices (CCD) by image-relaying structures separately. The errors between intersection points of two cross-talk images and centroid coordinates of actual beam are recorded automatically and sent to closed loop feedback control mechanism. Negative feedback keeps running until preset accuracy is reached. On the basis of above-mentioned design, the alignment optical path is built and the software is compiled, whereafter the experiment of double paths automatic alignment in electron pumped excimer laser amplifier is carried through. Meanwhile, the related influencing factors and the alignment precision are analyzed. Experimental results indicate that the alignment system can achieve the aiming direction of automatic aligning beams in short time. The analysis shows that the accuracy of alignment system is 0.63μrad and the beam maximum restoration error is 13.75μm. Furthermore, the bigger distance between the two cross-hairs, the higher precision of the system is. Therefore, the automatic alignment system has been used in angular multiplexing excimer Main Oscillation Power Amplification (MOPA) system and can satisfy the requirement of beam alignment precision on the whole.

  5. Initial alignment method for free space optics laser beam

    NASA Astrophysics Data System (ADS)

    Shimada, Yuta; Tashiro, Yuki; Izumi, Kiyotaka; Yoshida, Koichi; Tsujimura, Takeshi

    2016-08-01

    The authors have newly proposed and constructed an active free space optics transmission system. It is equipped with a motor driven laser emitting mechanism and positioning photodiodes, and it transmits a collimated thin laser beam and accurately steers the laser beam direction. It is necessary to introduce the laser beam within sensible range of the receiver in advance of laser beam tracking control. This paper studies an estimation method of laser reaching point for initial laser beam alignment. Distributed photodiodes detect laser luminescence at respective position, and the optical axis of laser beam is analytically presumed based on the Gaussian beam optics. Computer simulation evaluates the accuracy of the proposed estimation methods, and results disclose that the methods help us to guide the laser beam to a distant receiver.

  6. Laser Safety: A Laser Alignment Practical Training Course

    SciTech Connect

    Woods, Michael; Edstrom, Steve; /SLAC

    2011-01-26

    SLAC National Accelerator Laboratory has developed a Laser Alignment Practical Training Course as one of its core laser safety classes. The course is taught to small groups of up to three students and takes 1-3 hours to complete. This practical course is not a substitute for site-specific On-the-Job Training; it does, however, provide a good introduction in core laser safety practices that can be broadly applied. Alignment and diagnostic tasks are performed with low power lasers. Students learn safe alignment and diagnostic techniques and how to avoid common mistakes that might lead to an accident. The class is taught by laser supervisors, enabling them to assess the skill level of new laser personnel and determine the subsequent level of supervision needed. The course has six alignment tasks. For each task, discussion points are given for the instructor to review with the students. The optics setup includes different wavelength lasers, a beam expander, mirrors, irises, a periscope, a beam-splitting polarizer and a diffraction grating. Diagnostic tools include viewing cards, an IR viewer and a ccd camera. Laser eyewear is available to block some laser wavelengths in the setup.

  7. Sensitive Technique For Detecting Alignment Of Seed Laser

    NASA Technical Reports Server (NTRS)

    Barnes, Norman P.

    1994-01-01

    Frequency response near resonance measured. Improved technique for detection and quantification of alignment of injection-seeding laser with associated power-oscillator laser proposed. Particularly useful in indicating alignment at spectral purity greater than 98 percent because it becomes more sensitive as perfect alignment approached. In addition, implemented relatively easily, without turning on power-oscillator laser.

  8. Broadband laser polarization control with aligned carbon nanotubes.

    PubMed

    Yang, He; Fu, Bo; Li, Diao; Tian, Ying; Chen, Ya; Mattila, Marco; Yong, Zhenzhong; Li, Ru; Hassanien, Abdou; Yang, Changxi; Tittonen, Ilkka; Ren, Zhaoyu; Bai, Jintao; Li, Qingwen; Kauppinen, Esko I; Lipsanen, Harri; Sun, Zhipei

    2015-07-01

    We introduce a simple approach to fabricate an aligned carbon nanotube (ACNT) device for broadband polarization control in fiber laser systems. The ACNT device was fabricated by pulling from as-fabricated vertically-aligned carbon nanotube arrays. Their anisotropic properties are confirmed with various microscopy techniques. The device was then integrated into fiber laser systems (at two technologically important wavelengths of 1 and 1.5 μm) for polarization control. We obtained a linearly-polarized light output with the maximum extinction ratio of ∼12 dB. The output polarization direction could be fully controlled by the ACNT alignment direction in both lasers. To the best of our knowledge, this is the first time that the ACNT device is applied to polarization control in laser systems. Our results exhibit that the ACNT device is a simple, low-cost, and broadband polarizer to control laser polarization dynamics, for various photonic applications (such as material processing, polarization diversity detection in communications etc.), where linear polarization control is necessary. PMID:26060940

  9. Accurate Alignment of Plasma Channels Based on Laser Centroid Oscillations

    SciTech Connect

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

    2011-03-23

    A technique has been developed to accurately align a laser beam through a plasma channel by minimizing the shift in laser centroid and angle at the channel outptut. If only the shift in centroid or angle is measured, then accurate alignment is provided by minimizing laser centroid motion at the channel exit as the channel properties are scanned. The improvement in alignment accuracy provided by this technique is important for minimizing electron beam pointing errors in laser plasma accelerators.

  10. Technique for precise alignment of small diameter lasers

    SciTech Connect

    McCarthy, A.E.

    1980-01-01

    This report describes one technique used to obtain precise alignment of small diameter lasers. This procedure may be useful in the alignment of other lasers, but is especially valuable when aligning lasers that have a small diameter active medium and/or a curved mirror at one end of the laser cavity. The technique described in this report uses a He-Ne laser at one end of the laser being aligned and an autocollimator at the opposite end. These instruments are used to generate and observe the diffraction pattern and interference fringes caused by the limiting aperture of the lasing medium and the end mirrors of the cavity, respectively. These patterns and fringes are used both to establish a common optical axis between the active volume of the laser being aligned and the aligning instruments, and to set the end mirrors of the cavity normal to this axis.

  11. Well-pump alignment system

    DOEpatents

    Drumheller, Douglas S.

    1998-01-01

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping.

  12. SSC dipole magnet measurement and alignment using laser technology

    SciTech Connect

    Lipski, A.; Carson, J.A.; Robotham, W.F.

    1990-06-01

    Advancing into the prototype production stage of the SSC dipole magnets has introduced the need for a reliable, readily available, accurate alignment measuring system which gives results in real time. Components and subassemblies such as the cold mass and vacuum vessel are being measured for various geometric conditions such as straightness and twist. Variations from nominal dimensions are also being recorded so they can be compensated for during the final assembly process. Precision laser alignment takes specific advantages of the greatest accuracy. When combined with an optically produced perpendicular plane, this results in a system of geometric references of unparalleled accuracy. This paper describes the geometric requirements for SSC dipole magnet components, sub and final assemblies as well as the use of laser technology for surveying as part of the assembly process.

  13. Construction alignment sensor feasibility demonstrations (laser measurement)

    NASA Technical Reports Server (NTRS)

    Anderson, R. H.

    1980-01-01

    The design theory and trade-offs involved in the selection of laser heterodyne sensors for use in active control of spacecraft structures are discussed. These sensors include a HeNe distance measuring system for structures requiring accuracies to .1 mm, a CO2 distance measuring system for measuring unambiuously down to .01 microns, and vibration sensors based on both HeNe and CO2 lasers.

  14. Well-pump alignment system

    DOEpatents

    Drumheller, D.S.

    1998-10-20

    An improved well-pump for geothermal wells, an alignment system for a well-pump, and to a method for aligning a rotor and stator within a well-pump are disclosed, wherein the well-pump has a whistle assembly formed at a bottom portion thereof, such that variations in the frequency of the whistle, indicating misalignment, may be monitored during pumping. 6 figs.

  15. Space Mirror Alignment System

    NASA Technical Reports Server (NTRS)

    Jau, Bruno M.; McKinney, Colin; Smythe, Robert F.; Palmer, Dean L.

    2011-01-01

    An optical alignment mirror mechanism (AMM) has been developed with angular positioning accuracy of +/-0.2 arcsec. This requires the mirror s linear positioning actuators to have positioning resolutions of +/-112 nm to enable the mirror to meet the angular tip/tilt accuracy requirement. Demonstrated capabilities are 0.1 arc-sec angular mirror positioning accuracy, which translates into linear positioning resolutions at the actuator of 50 nm. The mechanism consists of a structure with sets of cross-directional flexures that enable the mirror s tip and tilt motion, a mirror with its kinematic mount, and two linear actuators. An actuator comprises a brushless DC motor, a linear ball screw, and a piezoelectric brake that holds the mirror s position while the unit is unpowered. An interferometric linear position sensor senses the actuator s position. The AMMs were developed for an Astrometric Beam Combiner (ABC) optical bench, which is part of an interferometer development. Custom electronics were also developed to accommodate the presence of multiple AMMs within the ABC and provide a compact, all-in-one solution to power and control the AMMs.

  16. Low-level laser therapy and invisible removal aligners.

    PubMed

    Caccianiga, G; Crestale, C; Cozzani, M; Piras, A; Mutinelli, S; Lo Giudice, A; Cordasco, G

    2016-01-01

    It seems that Low Level Laser Therapy (LLLT) stimulates orthodontic tooth movements, increasing the alveolar bone turnover. The aim of this study is to evaluate how LLLT can influence the orthodontic treatment with invisible removal aligner. A sample of 21 subjects was divided into two groups, a laser group (10 patients) and a control group (11 patients). All subjects were instructed to wear each aligner 12 hours a day for 2 weeks. Laser external bio-stimulation was given in the laser group every second week. The laser group successfully finished the treatment, while at 3rd – 5th aligner the control group did not finish the treatment. Laser treatment seemed to be better than treatment without laser. LLLT combined with aligners is able to favour, in 12 hours, the same tooth movement obtained by wearing the aligner 22 hours a day, according to the traditional protocol. This aspect could be useful for those patients who prefer not to use the aligners during the day. LLLT makes invisible removal aligner treatment more comfortable also because during the day the patients have to wear the aligners less hours than the treatment without laser. PMID:27469556

  17. Alignment and micro-inspection system

    SciTech Connect

    Chau, H; Hodgin, R L; Moua, K

    1998-09-15

    A video microscope system has been designed and installed in the C-tank, a 3-g, high-explosive firing chamber in HEAF (High Explosives Applications Facility in LLNL). This microscope system helps a great deal, not only for precision alignment of the laser beam on the minute target for the Fabry-Perot velocimeter, but also for in situ inspection of the target before and after the experiment. In addition, the video information can also be stored in the PC computer as database documentati

  18. Global Alignment System for Large Genomic Sequencing

    2002-03-01

    AVID is a global alignment system tailored for the alignment of large genomic sequences up to megabases in length. Features include the possibility of one sequence being in draft form, fast alignment, robustness and accuracy. The method is an anchor based alignment using maximal matches derived from suffix trees.

  19. Corrective optics space telescope axial replacement alignment system

    NASA Astrophysics Data System (ADS)

    Slusher, Robert B.; Satter, Michael J.; Kaplan, Michael L.; Martella, Mark A.; Freymiller, Ed D.; Buzzetta, Victor

    1993-10-01

    To facilitate the accurate placement and alignment of the corrective optics space telescope axial replacement (COSTAR) structure, mechanisms, and optics, the COSTAR Alignment System (CAS) has been designed and assembled. It consists of a 20-foot optical bench, support structures for holding and aligning the COSTAR instrument at various stages of assembly, a focal plane target fixture (FPTF) providing an accurate reference to the as-built Hubble Space Telescope (HST) focal plane, two alignment translation stages with interchangeable alignment telescopes and alignment lasers, and a Zygo Mark IV interferometer with a reference sphere custom designed to allow accurate double-pass operation of the COSTAR correction optics. The system is used to align the fixed optical bench (FOB), the track, the deployable optical bench (DOB), the mechanisms, and the optics to ensure that the correction mirrors are all located in the required positions and orientations on-orbit after deployment. In this paper, the layout of the CAS is presented and the various alignment operations are listed along with the relevant alignment requirements. In addition, calibration of the necessary support structure elements and alignment aids is described, including the two-axis translation stages, the latch positions, the FPTF, and the COSTAR-mounted alignment cubes.

  20. Laser Systems

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Tunable diode lasers are employed as radiation sources in high resolution infrared spectroscopy to determine spectral characteristics of gaseous compounds. With other laser systems, they are produced by Spectra-Physics, and used to monitor chemical processes, monitor production of quantity halogen lamps, etc. The Laser Analytics Division of Spectra-Physics credits the system's reliability to a program funded by Langley in the 1970s. Company no longer U.S.-owned. 5/22/97

  1. Strongly aligned gas-phase molecules at free-electron lasers

    DOE PAGES

    Kierspel, Thomas; Wiese, Joss; Mullins, Terry; Robinson, Joseph; Aquila, Andy; Barty, Anton; Bean, Richard; Boll, Rebecca; Boutet, Sebastien; Bucksbaum, Philip; et al

    2015-09-16

    Here, we demonstrate a novel experimental implementation to strongly align molecules at full repetition rates of free-electron lasers. We utilized the available in-house laser system at the coherent x-ray imaging beamline at the linac coherent light source. Chirped laser pulses, i.e., the direct output from the regenerative amplifier of the Ti:Sa chirped pulse amplification laser system, were used to strongly align 2, 5-diiodothiophene molecules in a molecular beam. The alignment laser pulses had pulse energies of a few mJ and a pulse duration of 94 ps. A degree of alignment ofmore » $$\\langle {\\mathrm{cos}}^{2}{\\theta }_{2{\\rm{D}}}\\rangle =0.85$$ was measured, limited by the intrinsic temperature of the molecular beam rather than by the available laser system. With the general availability of synchronized chirped-pulse-amplified near-infrared laser systems at short-wavelength laser facilities, our approach allows for the universal preparation of molecules tightly fixed in space for experiments with x-ray pulses.« less

  2. Strongly aligned gas-phase molecules at free-electron lasers

    SciTech Connect

    Kierspel, Thomas; Wiese, Joss; Mullins, Terry; Robinson, Joseph; Aquila, Andy; Barty, Anton; Bean, Richard; Boll, Rebecca; Boutet, Sebastien; Bucksbaum, Philip; Chapman, Henry N.; Christensen, Lauge; Fry, Alan; Hunter, Mark; Koglin, Jason E.; Liang, Mengning; Mariani, Valerio; Morgan, Andrew; Natan, Adi; Petrovic, Vladimir; Rolles, Daniel; Rudenko, Artem; Schnorr, Kirsten; Stapelfeldt, Henrik; Stern, Stephan; Thogersen, Jan; Yoon, Chun Hong; Wang, Fenglin; Trippel, Sebastian; Kupper, Jochen

    2015-09-16

    Here, we demonstrate a novel experimental implementation to strongly align molecules at full repetition rates of free-electron lasers. We utilized the available in-house laser system at the coherent x-ray imaging beamline at the linac coherent light source. Chirped laser pulses, i.e., the direct output from the regenerative amplifier of the Ti:Sa chirped pulse amplification laser system, were used to strongly align 2, 5-diiodothiophene molecules in a molecular beam. The alignment laser pulses had pulse energies of a few mJ and a pulse duration of 94 ps. A degree of alignment of $\\langle {\\mathrm{cos}}^{2}{\\theta }_{2{\\rm{D}}}\\rangle =0.85$ was measured, limited by the intrinsic temperature of the molecular beam rather than by the available laser system. With the general availability of synchronized chirped-pulse-amplified near-infrared laser systems at short-wavelength laser facilities, our approach allows for the universal preparation of molecules tightly fixed in space for experiments with x-ray pulses.

  3. Strongly aligned gas-phase molecules at free-electron lasers

    NASA Astrophysics Data System (ADS)

    Kierspel, Thomas; Wiese, Joss; Mullins, Terry; Robinson, Joseph; Aquila, Andy; Barty, Anton; Bean, Richard; Boll, Rebecca; Boutet, Sébastien; Bucksbaum, Philip; Chapman, Henry N.; Christensen, Lauge; Fry, Alan; Hunter, Mark; Koglin, Jason E.; Liang, Mengning; Mariani, Valerio; Morgan, Andrew; Natan, Adi; Petrovic, Vladimir; Rolles, Daniel; Rudenko, Artem; Schnorr, Kirsten; Stapelfeldt, Henrik; Stern, Stephan; Thøgersen, Jan; Yoon, Chun Hong; Wang, Fenglin; Trippel, Sebastian; Küpper, Jochen

    2015-10-01

    We demonstrate a novel experimental implementation to strongly align molecules at full repetition rates of free-electron lasers. We utilized the available in-house laser system at the coherent x-ray imaging beamline at the linac coherent light source. Chirped laser pulses, i.e., the direct output from the regenerative amplifier of the Ti:Sa chirped pulse amplification laser system, were used to strongly align 2, 5-diiodothiophene molecules in a molecular beam. The alignment laser pulses had pulse energies of a few mJ and a pulse duration of 94 ps. A degree of alignment of < {{cos}}2{θ }2{{D}}> =0.85 was measured, limited by the intrinsic temperature of the molecular beam rather than by the available laser system. With the general availability of synchronized chirped-pulse-amplified near-infrared laser systems at short-wavelength laser facilities, our approach allows for the universal preparation of molecules tightly fixed in space for experiments with x-ray pulses.

  4. Hybrid Online Mobile Laser Scanner Calibration Through Image Alignment by Mutual Information

    NASA Astrophysics Data System (ADS)

    Miled, Mourad; Soheilian, Bahman; Habets, Emmanuel; Vallet, Bruno

    2016-06-01

    This paper proposes an hybrid online calibration method for a laser scanner mounted on a mobile platform also equipped with an imaging system. The method relies on finding the calibration parameters that best align the acquired points cloud to the images. The quality of this intermodal alignment is measured by Mutual information between image luminance and points reflectance. The main advantage and motivation is ensuring pixel accurate alignment of images and point clouds acquired simultaneously, but it is also much more flexible than traditional laser calibration methods.

  5. Optical Device for Converting a Laser Beam into Two Co-aligned but Oppositely Directed Beams

    NASA Technical Reports Server (NTRS)

    Jennings, Donald

    2013-01-01

    Optical systems consisting of a series of optical elements require alignment from the input end to the output end. The optical elements can be mirrors, lenses, sources, detectors, or other devices. Complex optical systems are often difficult to align from end-to-end because the alignment beam must be inserted at one end in order for the beam to traverse the entire optical path to the other end. The ends of the optical train may not be easily accessible to the alignment beam. Typically, when a series of optical elements is to be aligned, an alignment laser beam is inserted into the optical path with a pick-off mirror at one end of the series of elements. But it may be impossible to insert the beam at an end-point. It can be difficult to locate the pick-off mirror at the desired position because there is not enough space, there is no mounting surface, or the location is occupied by a source, detector, or other component. Alternatively, the laser beam might be inserted at an intermediate location (not at an end-point) and sent, first in one direction and then the other, to the opposite ends of the optical system for alignment. However, in this case, alignment must be performed in two directions and extra effort is required to co-align the two beams to make them parallel and coincident, i.e., to follow the same path as an end-to-end beam. An optical device has been developed that accepts a laser beam as input and produces two co-aligned, but counter-propagating beams. In contrast to a conventional alignment laser placed at one end of the optical path, this invention can be placed at a convenient position within the optical train and aligned to send its two beams simultaneously along precisely opposite paths that, taken together, trace out exactly the same path as the conventional alignment laser. This invention allows the user the freedom to choose locations within the optical train for placement of the alignment beam. It is also self-aligned by design and requires

  6. Synthetic approach to designing optical alignment systems.

    PubMed

    Whang, A J; Gallagher, N C

    1988-08-15

    The objective of this study is twofold: to design reticle patterns with desirable alignment properties; to build an automatic alignment system using these patterns. We design such reticle patterns via a synthetic approach; the resultant patterns, so-called pseudonoise arrays, are binary and their autocorrelation functions are bilevel. Both properties are desirable in optical alignment. Besides, these arrays have attractive signal-to-noise ratio performance when employed in alignment. We implement the pseudonoise array as a 2-D cross-grating structure of which the grating period is much less than the wavelength of impinging light used for alignment. The short grating period feature, together with the use of polarized light, enables us to perform essentially 2-D optical alignment in one dimension. This alignment separability allows us to build a system that performs alignment automatically according to a simple 1-D algorithm. PMID:20539412

  7. Alignment performance of a 0.6-NA 364-nm laser direct writer

    NASA Astrophysics Data System (ADS)

    Bohan, Michael J.

    1990-06-01

    Alignment performance data is presented on a high resolution laser scanning lithography system. The alignment system is a through-the-lens on-axis design which features multiple optical paths such as bright-field and dark-field illumination and high and low magnification legs. Total system overlay is better than 0. 10 tm. 1. DW ALIGNMENT REQUIREMENTS Translating design data into patterned photoresist on wafers typically requires two lithographic steps. First data is transferred to a mask or reticle using either a laser scanning tool such as the ATEQ CORE-2500 or an e-beam system. Next the patterned mask or reticle is projected onto a wafer coated with resist. Throughout this paper I shall refer to systems which use two lithographic steps to transfer a pattern as Indirect Writers (1W). This is in contrast to Direct Writers (DW). As the name implies a DW patterns a wafer without the need for creation of a mask or reticle. 1W alignment systems must accurately register a wafer pattern to a reticle pattern. The most straightforward technique is to directly reference the reticle to the wafer through the projection lens. This approach eliminates baseline problems. 1W alignment systems require high precision. However since they have a reticle to reference (either directly or indirectly) absolute accuracy is not required. Measurements (alignments) are concerned only with the relative offset of the projected reticle image to a pattern on the wafer. The alignment system

  8. Computational studies of the x-ray scattering properties of laser aligned stilbene

    SciTech Connect

    Debnarova, Andrea; Techert, Simone; Schmatz, Stefan

    2011-02-07

    The enhancement of the x-ray scattering signal from partially aligned molecular samples is investigated. The alignment properties of the studied molecular system are modeled based on the method of laser alignment. With the advances in the area of laser alignment of molecules, the application of this sample manipulation technique promises a great potential for x-ray scattering measurements. Preferential alignment of molecules in an otherwise amorphous sample leads to constructive interference and thus increases the scattering intensity. This enhances the structural information encoded in the scattering images and enables improved resolution in studies of reaction dynamics, as in this work is shown for the example of the photo-isomerization of stilbene. We demonstrate that the scattering signal is strongly influenced by the alignment axis. Even the most basic one-dimensional alignment offers significant improvement compared to the structural information provided by a randomly oriented sample. Although the signal is sensitive to the uncertainty in the alignment angle, it offers encouraging results even at realistic alignment uncertainties.

  9. Alignments between galaxies, satellite systems and haloes

    NASA Astrophysics Data System (ADS)

    Shao, Shi; Cautun, Marius; Frenk, Carlos S.; Gao, Liang; Crain, Robert A.; Schaller, Matthieu; Schaye, Joop; Theuns, Tom

    2016-08-01

    The spatial distribution of the satellite populations of the Milky Way and Andromeda are puzzling in that they are nearly perpendicular to the discs of their central galaxies. To understand the origin of such configurations we study the alignment of the central galaxy, satellite system and dark matter halo in the largest of the `Evolution and Assembly of GaLaxies and their Environments' (EAGLE) simulation. We find that centrals and their satellite systems tend to be well aligned with their haloes, with a median misalignment angle of 33° in both cases. While the centrals are better aligned with the inner 10 kpc halo, the satellite systems are better aligned with the entire halo indicating that satellites preferentially trace the outer halo. The central-satellite alignment is weak (median misalignment angle of 52°) and we find that around 20 per cent of systems have a misalignment angle larger than 78°, which is the value for the Milky Way. The central-satellite alignment is a consequence of the tendency of both components to align with the dark matter halo. As a consequence, when the central is parallel to the satellite system, it also tends to be parallel to the halo. In contrast, if the central is perpendicular to the satellite system, as in the case of the Milky Way and Andromeda, then the central-halo alignment is much weaker. Dispersion-dominated (spheroidal) centrals have a stronger alignment with both their halo and their satellites than rotation-dominated (disc) centrals. We also found that the halo, the central galaxy and the satellite system tend to be aligned with the surrounding large-scale distribution of matter, with the halo being the better aligned of the three.

  10. Automated interferometric alignment system for paraboloidal mirrors

    DOEpatents

    Maxey, L.C.

    1993-09-28

    A method is described for a systematic method of interpreting interference fringes obtained by using a corner cube retroreflector as an alignment aid when aligning a paraboloid to a spherical wavefront. This is applicable to any general case where such alignment is required, but is specifically applicable in the case of aligning an autocollimating test using a diverging beam wavefront. In addition, the method provides information which can be systematically interpreted such that independent information about pitch, yaw and focus errors can be obtained. Thus, the system lends itself readily to automation. Finally, although the method is developed specifically for paraboloids, it can be seen to be applicable to a variety of other aspheric optics when applied in combination with a wavefront corrector that produces a wavefront which, when reflected from the correctly aligned aspheric surface will produce a collimated wavefront like that obtained from the paraboloid when it is correctly aligned to a spherical wavefront. 14 figures.

  11. Design progress for the National Ignition Facility laser alignment and beam diagnostics

    SciTech Connect

    Thomas, S W; Bliss, E S; Boege, S J; Boyd, R D; Bronisz, L; Bruker, J; C W Lauman, McCarville, T J; Chocol, C; Davis, D T; Demaret, R D; Feldman, M; Gates, A J; Holdener, F R; Hollis, J; Knopp, C F; Kyker, R; Miller, J L; Miller-Kamm, V J; Rivera, W E; Salmon, J T; Severyn, J R; Sheem, S K; Sheridan, T; Thompson, D Y; Wang, M F; Witaker, D; Yoeman, M F; Zacharias, R A

    1998-09-09

    Earlier papers have described approaches to NIF alignment and laser diagnostics tasks. 1,2,3 Now, detailed design of alignment and diagnostic systems for the National Ignition Facility (NIF) laser is in its last year. Specifications are more detailed, additional analyses have been completed, Pro-E models have been developed, and prototypes of specific items have been built. In this paper we update top level concepts, illustrate specific areas of progress, and show design implementations as represented by prototype hardware. The alignment light source network has been fully defined. It utilizes an optimized number of lasers combined with fiber optic distribution to provide the chain alignment beams, system centering references, final spatial filter pinhole references, target alignment beams, and wavefront reference beams. The input and output sensors are being prototyped. They are located respectively in the front end just before beam injection into the full aperture chain and at the transport spatial filter, where the full energy infrared beam leaves the laser. The modularity of the input sensor is improved, and each output sensor mechanical package now incorporates instrumentation for four beams. Additional prototype hardware has been tested for function, and lifetime tests are underway. We report some initial results.

  12. Counterintuitive alignment of H2(+) in intense femtosecond laser fields.

    PubMed

    Frasinski, L J; Plumridge, J; Posthumus, J H; Codling, K; Taday, P F; Divall, E J; Langley, A J

    2001-03-19

    The multiphoton ionization of H2 has been studied using laser pulses of 266 nm wavelength, 250 fs duration, and 5x10(13) W/cm(2) peak intensity. Dissociation of H2(+) via one-photon absorption proceeds through two channels with markedly different proton angular distributions. The lower-energy channel (2.6 eV kinetic energy release) is produced in the bond softening mechanism, which generates parallel alignment. The higher-energy channel (3.5 eV) originates from population trapping in a light-induced bound state, where bond hardening generates orthogonal, counterintuitive alignment.

  13. Alignment performance monitoring for ASML systems

    NASA Astrophysics Data System (ADS)

    Chung, Woong-Jae; Temchenko, Vlad; Hauck, Tarja; Schmidt, Sebastian

    2006-03-01

    In today's semiconductor industry downscaling of the IC design puts a stringent requirement on pattern overlay control. Tighter overlay requirements lead to exceedingly higher rework rates, meaning additional costs to manufacturing. Better alignment control became a target of engineering efforts to decrease rework rate for high-end technologies. Overlay performance is influenced by known parameters such as "Shift, Scaling, Rotation, etc", and unknown parameters defined as "Process Induced Variation", which are difficult to control by means of a process automation system. In reality, this process-induced variation leads to a strong wafer to wafer, or lot to lot variation, which are not easy to detect in the mass-production environment which uses sampling overlay measurements for only several wafers in a lot. An engineering task of finding and correcting a root cause for Process Induced Variations of overlay performance will be greatly simplified if the unknown parameters could be tracked for each wafer. This paper introduces an alignment performance monitoring method based on analysis of automatically generated "AWE" files for ASML scanner systems. Because "AWE" files include alignment results for each aligned wafer, it is possible to use them for monitoring, controlling and correcting the causes of "process induced" overlay performance without requiring extra measurement time. Since "AWE" files include alignment information for different alignment marks, it is also possible to select and optimize the best alignment recipe for each alignment strategy. Several case studies provided in our paper will demonstrate how AWE file analysis can be used to assist engineer in interpreting pattern alignment data. Since implementing our alignment data monitoring method, we were able to achieve significant improvement of alignment and overlay performance without additional overlay measurement time. We also noticed that the rework rate coming from alignment went down and

  14. Partial Automated Alignment and Integration System

    NASA Technical Reports Server (NTRS)

    Kelley, Gary Wayne (Inventor)

    2014-01-01

    The present invention is a Partial Automated Alignment and Integration System (PAAIS) used to automate the alignment and integration of space vehicle components. A PAAIS includes ground support apparatuses, a track assembly with a plurality of energy-emitting components and an energy-receiving component containing a plurality of energy-receiving surfaces. Communication components and processors allow communication and feedback through PAAIS.

  15. Automated interferometric alignment system for paraboloidal mirrors

    DOEpatents

    Maxey, L. Curtis

    1993-01-01

    A method is described for a systematic method of interpreting interference fringes obtained by using a corner cube retroreflector as an alignment aid when aigning a paraboloid to a spherical wavefront. This is applicable to any general case where such alignment is required, but is specifically applicable in the case of aligning an autocollimating test using a diverging beam wavefront. In addition, the method provides information which can be systematically interpreted such that independent information about pitch, yaw and focus errors can be obtained. Thus, the system lends itself readily to automation. Finally, although the method is developed specifically for paraboloids, it can be seen to be applicable to a variety of other aspheric optics when applied in combination with a wavefront corrector that produces a wavefront which, when reflected from the correctly aligned aspheric surface will produce a collimated wavefront like that obtained from the paraboloid when it is correctly aligned to a spherical wavefront.

  16. Heterodyne laser spectroscopy system

    DOEpatents

    Wyeth, Richard W.; Paisner, Jeffrey A.; Story, Thomas

    1989-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency and the like, and provides spectral analysis of a laser beam.

  17. Heterodyne laser spectroscopy system

    DOEpatents

    Wyeth, Richard W.; Paisner, Jeffrey A.; Story, Thomas

    1990-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency, and provides spectral analysis of a laser beam.

  18. Automatic laser beam alignment using blob detection for an environment monitoring spectroscopy

    NASA Astrophysics Data System (ADS)

    Khidir, Jarjees; Chen, Youhua; Anderson, Gary

    2013-05-01

    This paper describes a fully automated system to align an infra-red laser beam with a small retro-reflector over a wide range of distances. The component development and test were especially used for an open-path spectrometer gas detection system. Using blob detection under OpenCV library, an automatic alignment algorithm was designed to achieve fast and accurate target detection in a complex background environment. Test results are presented to show that the proposed algorithm has been successfully applied to various target distances and environment conditions.

  19. Smart and precise alignment of optical systems

    NASA Astrophysics Data System (ADS)

    Langehanenberg, Patrik; Heinisch, Josef; Stickler, Daniel

    2013-09-01

    For the assembly of any kind of optical systems the precise centration of every single element is of particular importance. Classically the precise alignment of optical components is based on the precise centering of all components to an external axis (usually a high-precision rotary spindle axis). Main drawback of this timeconsuming process is that it is significantly sensitive to misalignments of the reference (e.g. the housing) axis. In order to facilitate process in this contribution we present a novel alignment strategy for the TRIOPTICS OptiCentric® instrument family that directly aligns two elements with respect to each other by measuring the first element's axis and using this axis as alignment reference without the detour of considering an external reference. According to the optical design any axis in the system can be chosen as target axis. In case of the alignment to a barrel this axis is measured by using a distance sensor (e.g., the classically used dial indicator). Instead of fine alignment the obtained data is used for the calculation of its orientation within the setup. Alternatively, the axis of an optical element (single lens or group of lenses) whose orientation is measured with the standard OptiCentric MultiLens concept can be used as a reference. In the instrument's software the decentering of the adjusting element to the calculated axis is displayed in realtime and indicated by a target mark that can be used for the manual alignment. In addition, the obtained information can also be applied for active and fully automated alignment of lens assemblies with the help of motorized actuators.

  20. Compact laser amplifier system

    DOEpatents

    Carr, R.B.

    1974-02-26

    A compact laser amplifier system is described in which a plurality of face-pumped annular disks, aligned along a common axis, independently radially amplify a stimulating light pulse. Partially reflective or lasing means, coaxially positioned at the center of each annualar disk, radially deflects a stimulating light directed down the common axis uniformly into each disk for amplification, such that the light is amplified by the disks in a parallel manner. Circumferential reflecting means coaxially disposed around each disk directs amplified light emission, either toward a common point or in a common direction. (Official Gazette)

  1. Pupil Alignment Measuring Technique and Alignment Reference for Instruments or Optical Systems

    NASA Technical Reports Server (NTRS)

    Hagopian, John G.

    2010-01-01

    A technique was created to measure the pupil alignment of instruments in situ by measuring calibrated pupil alignment references (PARs) in instruments. The PAR can also be measured using an alignment telescope or an imaging system. PAR allows the verification of the science instrument (SI) pupil alignment at the integrated science instrument module (ISIM) level of assembly at ambient and cryogenic operating temperature. This will allow verification of the ISIM+SI alignment, and provide feedback to realign the SI if necessary.

  2. Angular Alignment Testing of Laser Mirror Mounts Under Temperature Cycling

    NASA Technical Reports Server (NTRS)

    Bullock, K. T.; DeYoung, R. J.; Sandford, S. P.

    1997-01-01

    A number of commercial and custom-built laser mirror mounts were tested for angular alignment sensitivity during temperature cycling from room temperature (20 C) to 40 C. A Nd:YAG laser beam was reflected off a mirror that was held by the mount under test and was directed to a position-sensitive detector. Horizontal and vertical movement of the reflected beam was recorded, and the angular movement, as a function of temperature (coefficient of thermal tilt (CTT)) was calculated from these data. In addition, the amount of hysteresis in the movement after cycling from room temperature to 40 C and back was determined. All commercial mounts showed greater angular movement than the simpler National Aeronautics and Space Administration Lidar Atmospheric Sensing Experiment (NASA LASE) custom mirror mounts.

  3. Photoelectron diffraction from laser-aligned molecules with X-ray free-electron laser pulses

    PubMed Central

    Nakajima, Kyo; Teramoto, Takahiro; Akagi, Hiroshi; Fujikawa, Takashi; Majima, Takuya; Minemoto, Shinichirou; Ogawa, Kanade; Sakai, Hirofumi; Togashi, Tadashi; Tono, Kensuke; Tsuru, Shota; Wada, Ken; Yabashi, Makina; Yagishita, Akira

    2015-01-01

    We report on the measurement of deep inner-shell 2p X-ray photoelectron diffraction (XPD) patterns from laser-aligned I2 molecules using X-ray free-electron laser (XFEL) pulses. The XPD patterns of the I2 molecules, aligned parallel to the polarization vector of the XFEL, were well matched with our theoretical calculations. Further, we propose a criterion for applying our molecular-structure-determination methodology to the experimental XPD data. In turn, we have demonstrated that this approach is a significant step toward the time-resolved imaging of molecular structures. PMID:26369428

  4. Iterative alignment of reflector segments using a laser tracker

    NASA Astrophysics Data System (ADS)

    Cabrera Cuevas, Lizeth; Lucero Alvarez, Maribel; Leon-Huerta, Andrea; Hernandez Rios, Emilio; Hernandez Lázaro, Josefina; Tzile Torres, Carlos; Castro Santos, David; Gale, David M.; Wilson, Grant; Narayanan, Gopal; Smith, David R.

    2013-04-01

    The Large Millimeter Telescope (LMT) is a 50m diameter millimetre-wave radio telescope situated on the summit of Sierra Negra, Puebla, at an altitude of 4600 meters. The reflector surface of the LMT currently employs84 segments arranged in three annular rings. Each segment is comprised of 8 precision composite subpanels located on five threaded adjusters. During the current primary surface refurbishment, individual segments are aligned in the telescope basement using a laser tracker. This allows increased spatial resolution in shorter timescales, resulting in the opportunity for improved logistics and increased alignment precision. To perform segment alignment an iterative process is carried out whereby the surface is measured and subpanel deformations are corrected with the goal of 40 microns RMS. In practice we have been able to achieve RMS errors of almost 20 microns, with 35 microns typical. The number of iterations varies from around ten to over 20, depending mainly on the behaviour of the mechanical adjusters that support the individual subpanels. Cross marks scribed on the reflector surface are used as fiducials, because their positions on the paraboloid are well known. Measurement data is processed using a robust curve fitting algorithm which provides a map of the surface showing the subpanel deviations. From this map the required subpanel adjuster movements are calculated allowing surface improvement in a stepwise manner.

  5. Active alignment/contact verification system

    DOEpatents

    Greenbaum, William M.

    2000-01-01

    A system involving an active (i.e. electrical) technique for the verification of: 1) close tolerance mechanical alignment between two component, and 2) electrical contact between mating through an elastomeric interface. For example, the two components may be an alumina carrier and a printed circuit board, two mating parts that are extremely small, high density parts and require alignment within a fraction of a mil, as well as a specified interface point of engagement between the parts. The system comprises pairs of conductive structures defined in the surfaces layers of the alumina carrier and the printed circuit board, for example. The first pair of conductive structures relate to item (1) above and permit alignment verification between mating parts. The second pair of conductive structures relate to item (2) above and permit verification of electrical contact between mating parts.

  6. Laser beam monitoring system

    DOEpatents

    Weil, Bradley S.; Wetherington, Jr., Grady R.

    1985-01-01

    Laser beam monitoring systems include laser-transparent plates set at an angle to the laser beam passing therethrough and light sensor for detecting light reflected from an object on which the laser beam impinges.

  7. Propagation and stability characteristics of a 500-m-long laser-based fiducial line for high-precision alignment of long-distance linear accelerators.

    PubMed

    Suwada, Tsuyoshi; Satoh, Masanori; Telada, Souichi; Minoshima, Kaoru

    2013-09-01

    A laser-based alignment system with a He-Ne laser has been newly developed in order to precisely align accelerator units at the KEKB injector linac. The laser beam was first implemented as a 500-m-long fiducial straight line for alignment measurements. We experimentally investigated the propagation and stability characteristics of the laser beam passing through laser pipes in vacuum. The pointing stability at the last fiducial point was successfully obtained with the transverse displacements of ±40 μm level in one standard deviation by applying a feedback control. This pointing stability corresponds to an angle of ±0.08 μrad. This report contains a detailed description of the experimental investigation for the propagation and stability characteristics of the laser beam in the laser-based alignment system for long-distance linear accelerators.

  8. Propagation and stability characteristics of a 500-m-long laser-based fiducial line for high-precision alignment of long-distance linear accelerators

    SciTech Connect

    Suwada, Tsuyoshi; Satoh, Masanori; Telada, Souichi; Minoshima, Kaoru

    2013-09-15

    A laser-based alignment system with a He-Ne laser has been newly developed in order to precisely align accelerator units at the KEKB injector linac. The laser beam was first implemented as a 500-m-long fiducial straight line for alignment measurements. We experimentally investigated the propagation and stability characteristics of the laser beam passing through laser pipes in vacuum. The pointing stability at the last fiducial point was successfully obtained with the transverse displacements of ±40 μm level in one standard deviation by applying a feedback control. This pointing stability corresponds to an angle of ±0.08 μrad. This report contains a detailed description of the experimental investigation for the propagation and stability characteristics of the laser beam in the laser-based alignment system for long-distance linear accelerators.

  9. Assembly and alignment of infrared refractive system

    NASA Astrophysics Data System (ADS)

    Yang, Lin; Lin, Jian-chun; Wang, Ya-jing; Chen, Fan-sheng

    2013-09-01

    Optical systems for scientific instrumentation frequently include lens or mirrors with critical mechanical requirements. Position issues of those components are inextricably bound to the efficiency of the instrument. The position referring to the lens system mainly means spacer and rotation of all elements concerned. Instrument could not be completed without the accuracy assembly even the previous design was top one. The alignment of infrared optical system always is a tough thing due to the IR material being opaque to visible light which hardly effect on the imaging ability of the system. In this paper a large-aperture IR refractive system was described in details and the alignment of this system was presented. The brief work describes the assembly and integration of the camera barrel in lab. First of all, all the mechanical elements must be manufactured with high accuracy requirements to meet alignment tolerances and minimum errors mostly could be ignored. The rotations relative to the optical axis were hardy restricted by the space between barrel and cells. The lens vertex displacements were determined through high accuracy titanium alloy spacer. So the actual shape data of the optical lenses were obtained by coordinate measuring machining (CMM) to calculate the real space between lenses after alignment1 done. All the measured results were critical for instruction of the practical assemble. Based on the properties and tolerances of the system, the camera barrel includes sets of six lenses with their respective supports and cells which are composed of two parts: the flied lens group and the relay lenses group. The first one was aligned by the geometry centering used CMM. And the relay lenses were integrated one by one after centered individually with a classical centering instrument. Then the two separate components were assembled under the monitor of the CMM with micron precision. Three parameters on the opti-mechanical elements which include decenter, tilt and

  10. Automatic laser alignment for multifocal microscopy using a LCOS SLM and a 32×32 pixel CMOS SPAD array

    NASA Astrophysics Data System (ADS)

    Tyndall, David; Walker, Richard; Nguyen, Krzysztof; Galland, Rémi; Gao, Jie; Wang, Irène; Kloster, Meike; Delon, Antoine; Henderson, Robert

    2011-07-01

    Alignment of a laser to a point source detector for confocal microscopy can be a time-consuming task. The problem is further exacerbated when multiple laser excitation spots are used in conjunction with a multiple pixel single photon detector; in addition to X, Y and Z positioning, pixels in a 2D array detector can also be misaligned in roll, pitch and yaw with respect to each other, causing magnification, rotation and focus variation across the array. We present a technique for automated multiple point laser alignment to overcome these issues using closed-loop feedback between a laser illuminated computer controlled Liquid Crystal on Silicon Spatial Light Modulator (LCOS-SLM) acting as the excitation source and a 32×32 pixel CMOS Single Photon Avalanche Diode (SPAD) array as the multiple pixel detection element. The alignment procedure is discussed and simulated to prove its feasibility before being implemented and tested in a practical optical system. We show that it is possible to align each independent laser point in a sub-second time scale, significantly simplifying and speeding up experimental set-up times. The approach provides a solution to the difficulties associated with multiple point confocal laser alignment to multiple point detector arrays, paving the way for further advances in applications such as Fluorescence Correlation Spectroscopy (FCS) and Fluorescence Lifetime Imaging Microscopy (FLIM).

  11. Dynamic interferometer alignment and its utility in UV Fourier transform spectrometer systems

    NASA Technical Reports Server (NTRS)

    Dorval, Rick K.; Engel, James R.; Wyntjes, Geert J.

    1993-01-01

    Dynamic alignment has been demonstrated as a practical approach to alignment maintenance for systems in the infrared region of the spectrum. On the basis of work done by OPTRA, this technique was introduced in commercial Fourier transform spectrometer systems in 1982 and in various forms is now available from a number of manufacturers. This paper reports on work by OPTRA to extend the basic technique to systems operating in the ultraviolet. In addition, this paper reports the preliminary results of the development of an alignment system using a laser diode in place of a gas laser normally found in dynamic alignment systems. A unique optical system and spatial heterodyne technique allows for achievement of a metrology system with characteristics that fully satisfy the requirements of an ultraviolet spectrometer system.

  12. Nonadiabatic alignment of van der Waals--force-bound argon dimers by femtosecond laser pulses

    SciTech Connect

    Wu, J.; Vredenborg, A.; Ulrich, B.; Schmidt, L. Ph. H.; Meckel, M.; Voss, S.; Sann, H.; Kim, H.; Jahnke, T.; Doerner, R.

    2011-06-15

    We demonstrated that the weak van der Waals-force-bound argon dimer can be nonadiabatically aligned by nonresonant femtosecond laser pulses, showing periodic alignment and anti-alignment revivals after the extinction of the laser pulse. Based on the measured nonadiabatic alignment trace, the rotational constant of the argon dimer ground state is determined to be B{sub 0}= 0.05756 {+-} 0.00004 cm{sup -1}. Noticeable alignment dependence of frustrated tunneling ionization and bond-softening induced dissociation of the argon dimer are observed.

  13. Heterodyne laser diagnostic system

    DOEpatents

    Globig, Michael A.; Johnson, Michael A.; Wyeth, Richard W.

    1990-01-01

    The heterodyne laser diagnostic system includes, in one embodiment, an average power pulsed laser optical spectrum analyzer for determining the average power of the pulsed laser. In another embodiment, the system includes a pulsed laser instantaneous optical frequency measurement for determining the instantaneous optical frequency of the pulsed laser.

  14. Automatic Alignment System for the National Ignition Facility

    SciTech Connect

    Wilhlelmsen, K C; Awwal, A S; Ferguson, S W; Horowitz, B; Miller Kamm, V J; Reynolds, C A

    2007-10-04

    The automatic alignment system for the National Ignition Facility (NIF) is a large-scale parallel system that directs all 192 laser beams along the 300-m optical path to a 50-micron focus at target chamber in less than 30 minutes. The system commands 9,000 stepping motors to adjust mirrors and other optics. Twenty-two control loops per beamline request image processing services running on a LINUX cluster to analyze high-resolution images of the beam and references. Process-leveling assures the computational load is evenly spread on the cluster. Algorithms also estimate measurement accuracy and reject off-normal images. One challenge to achieving rapid alignment of beams in parallel is the efficient coordination of shared laser devices, such as sensors that are configurable to monitor multiple beams. Contention for shared resources is managed by the Component Mediation System, which precludes deadlocks and optimizes device motions using a hierarchical component structure. A reservation service provided by the software framework prevents interference from competing instances of automated controls or from the actions of system operators. The design, architecture and performance of the system will be discussed.

  15. Visual attitude orientation and alignment system

    NASA Technical Reports Server (NTRS)

    Beam, R. A.; Morris, D. B.

    1967-01-01

    Active vehicle optical alignment aid and a passive vehicle three-dimensional alignment target ensure proper orientation and alignment plus control of the closure range and rate between two bodies, one in controlled motion and one at rest.

  16. Experience report with the Alignment Diagnostic System

    SciTech Connect

    Gassner, Georg; /SLAC

    2011-03-03

    Since 2009 an Alignment Diagnostic System (ADS) has been operating at the undulator of the new Linac Coherent Light Source at SLAC National Accelerator Laboratory. The undulator spans a distance of 132 meters and is structured into 33 segments. Each segment is equipped with four hydrostatic leveling sensors and four wire position monitors. This report describes the set up and reflects the experience gained with the ADS.

  17. Operation and maintenance manual for the optical alignment system (OAS) system 6250

    SciTech Connect

    Pardini, A.F., Westinghouse Hanford

    1996-07-16

    The OAS is a camera and laser system that will be used as an end effector on the LDUA to properly align the arm with the entry riser. It is attached to the LDUA by means of a Tool Interface Plat (TIP) which provides a feed through for all electrical and pneumatic utilities needed by the end effector to operate.

  18. A Fuzzy Logic Based Controller for the Automated Alignment of a Laser-beam-smoothing Spatial Filter

    NASA Technical Reports Server (NTRS)

    Krasowski, M. J.; Dickens, D. E.

    1992-01-01

    A fuzzy logic based controller for a laser-beam-smoothing spatial filter is described. It is demonstrated that a human operator's alignment actions can easily be described by a system of fuzzy rules of inference. The final configuration uses inexpensive, off-the-shelf hardware and allows for a compact, readily implemented embedded control system.

  19. SU-E-T-484: A New Method of Aligning Patient Setup Lasers in Radiation Therapy

    SciTech Connect

    Hwang, U; Lim, Y; Cho, K; Jeong, C; Kim, M; Jeong, J; Park, J; Shin, D; Lee, S; Kim, J; Choi, S; Kwak, J; Yoon, K; Park, S; Kim, S

    2014-06-01

    Purpose: To develop a new method to align the patient setup lasers in radiation therapy and examine its validity and effectiveness. Methods: The new laser alignment method was realized by a device composed of both a metallic base plate and few acrylic transparent plates with a cross hair line on each of them. The holders of radiochromic films were prepared in the device to find a radiation isocenter. The right laser positions could be found optically by matching the shadows of all the cross hairs in the gantry head and the device. The repeatability and reproducibility (R and R) of laser alignments and the dependency of the alignment on the position error of the light source were evaluated by comparing the standard deviations and the means of the measured laser positions. After aligning the lasers optically, a radiation isocenter was found by a collimator spoke shot and the gantry spoke shot, and then the lasers were parallely translated to the isocenter. Results: In the R and R test, the standard deviation was 1.14 mm for the new method whereas it was 1.49 mm or 2.76 mm for the conventional method with either high- or low-precision levels. In the test of the dependency on the position error of the light source, the mean laser position was shifted by 5.3 mm corresponding to the shift of the light source, 4.8 mm for the new method, but for the conventional method the laser position was shifted more than 7 times than that. The positional shift could be corrected by a parallel translation to the isocenter in the new method. Conclusion: A new laser alignment method was devised for radiation therapy and tested successfully. The method enabled us to align the lasers easily and accurately without repetition, and all lasers could be finally aligned to the radiation isocenter.

  20. A new method and device of aligning patient setup lasers in radiation therapy.

    PubMed

    Hwang, Ui-Jung; Jo, Kwanghyun; Lim, Young Kyung; Kwak, Jung Won; Choi, Sang Hyuon; Jeong, Chiyoung; Kim, Mi Young; Jeong, Jong Hwi; Shin, Dongho; Lee, Se Byeong; Park, Jeong-Hoon; Park, Sung Yong; Kim, Siyong

    2016-01-08

    The aim of this study is to develop a new method to align the patient setup lasers in a radiation therapy treatment room and examine its validity and efficiency. The new laser alignment method is realized by a device composed of both a metallic base plate and a few acrylic transparent plates. Except one, every plate has either a crosshair line (CHL) or a single vertical line that is used for alignment. Two holders for radiochromic film insertion are prepared in the device to find a radiation isocenter. The right laser positions can be found optically by matching the shadows of all the CHLs in the gantry head and the device. The reproducibility, accuracy, and efficiency of laser alignment and the dependency on the position error of the light source were evaluated by comparing the means and the standard deviations of the measured laser positions. After the optical alignment of the lasers, the radiation isocenter was found by the gantry and collimator star shots, and then the lasers were translated parallel to the isocenter. In the laser position reproducibility test, the mean and standard deviation on the wall of treatment room were 32.3 ± 0.93 mm for the new method whereas they were 33.4 ± 1.49 mm for the conventional method. The mean alignment accuracy was 1.4 mm for the new method, and 2.1 mm for the conventional method on the walls. In the test of the dependency on the light source position error, the mean laser position was shifted just by a similar amount of the shift of the light source in the new method, but it was greatly magnified in the conventional method. In this study, a new laser alignment method was devised and evaluated successfully. The new method provided more accurate, more reproducible, and faster alignment of the lasers than the conventional method.

  1. A new method and device of aligning patient setup lasers in radiation therapy.

    PubMed

    Hwang, Ui-Jung; Jo, Kwanghyun; Lim, Young Kyung; Kwak, Jung Won; Choi, Sang Hyuon; Jeong, Chiyoung; Kim, Mi Young; Jeong, Jong Hwi; Shin, Dongho; Lee, Se Byeong; Park, Jeong-Hoon; Park, Sung Yong; Kim, Siyong

    2016-01-01

    The aim of this study is to develop a new method to align the patient setup lasers in a radiation therapy treatment room and examine its validity and efficiency. The new laser alignment method is realized by a device composed of both a metallic base plate and a few acrylic transparent plates. Except one, every plate has either a crosshair line (CHL) or a single vertical line that is used for alignment. Two holders for radiochromic film insertion are prepared in the device to find a radiation isocenter. The right laser positions can be found optically by matching the shadows of all the CHLs in the gantry head and the device. The reproducibility, accuracy, and efficiency of laser alignment and the dependency on the position error of the light source were evaluated by comparing the means and the standard deviations of the measured laser positions. After the optical alignment of the lasers, the radiation isocenter was found by the gantry and collimator star shots, and then the lasers were translated parallel to the isocenter. In the laser position reproducibility test, the mean and standard deviation on the wall of treatment room were 32.3 ± 0.93 mm for the new method whereas they were 33.4 ± 1.49 mm for the conventional method. The mean alignment accuracy was 1.4 mm for the new method, and 2.1 mm for the conventional method on the walls. In the test of the dependency on the light source position error, the mean laser position was shifted just by a similar amount of the shift of the light source in the new method, but it was greatly magnified in the conventional method. In this study, a new laser alignment method was devised and evaluated successfully. The new method provided more accurate, more reproducible, and faster alignment of the lasers than the conventional method. PMID:26894331

  2. Portable weighing system with alignment features

    SciTech Connect

    Abercrombie, Robert Knox; Richardson, Gregory David; Scudiere, Matthew Bligh; Sheldon, Frederick T.

    2012-11-06

    A system for weighing a load is disclosed. The weighing system includes a pad having at least one transducer for weighing a load disposed on the pad. In some embodiments the pad has a plurality of foot members and the weighing system may include a plate that disposed underneath the pad for receiving the plurality of foot member and for aligning the foot members when the weighing system is installed. The weighing system may include a spacer disposed adjacent the pad and in some embodiments, a spacer anchor operatively secures the spacer to a support surface, such as a plate, a railway bed, or a roadway. In some embodiments the spacer anchor operatively secures both the spacer and the pad to a roadway.

  3. Hypersonic gasdynamic laser system

    SciTech Connect

    Foreman, K.M.; Maciulaitis, A.

    1990-05-22

    This patent describes a visible, or near to mid infra-red, hypersonic gas dynamic laser system. It comprises: a hypersonic vehicle for carrying the hypersonic gas dynamic laser system, and also providing high energy ram air for thermodynamic excitation and supply of the laser gas; a laser cavity defined within the hypersonic vehicle and having a laser cavity inlet for the laser cavity formed by an opening in the hypersonic vehicle, such that ram air directed through the laser cavity opening supports gas dynamic lasing operations at wavelengths less than 10.6{mu} meters in the laser cavity; and an optical train for collecting the laser radiation from the laser cavity and directing it as a substantially collimated laser beam to an output aperture defined by an opening in the hypersonic vehicle to allow the laser beam to be directed against a target.

  4. Laser satellite power systems

    SciTech Connect

    Walbridge, E.W.

    1980-01-01

    A laser satellite power system (SPS) converts solar power captured by earth-orbiting satellites into electrical power on the earth's surface, the satellite-to-ground transmission of power being effected by laser beam. The laser SPS may be an alternative to the microwave SPS. Microwaves easily penetrate clouds while laser radiation does not. Although there is this major disadvantage to a laser SPS, that system has four important advantages over the microwave alternative: (1) land requirements are much less, (2) radiation levels are low outside the laser ground stations, (3) laser beam sidelobes are not expected to interfere with electromagnetic systems, and (4) the laser system lends itself to small-scale demonstration. After describing lasers and how they work, the report discusses the five lasers that are candidates for application in a laser SPS: electric discharge lasers, direct and indirect solar pumped lasers, free electron lasers, and closed-cycle chemical lasers. The Lockheed laser SPS is examined in some detail. To determine whether a laser SPS will be worthy of future deployment, its capabilities need to be better understood and its attractiveness relative to other electric power options better assessed. First priority should be given to potential program stoppers, e.g., beam attenuation by clouds. If investigation shows these potential program stoppers to be resolvable, further research should investigate lasers that are particularly promising for SPS application.

  5. Aligning Performance: Improving People, Systems, and Organizations.

    ERIC Educational Resources Information Center

    Langdon, Danny

    Performance is the actual work that is done to assure that an organization achieves its mission, and aligning that performance assures that the path to the mission is harmonious. Alignment exists when all people involved understand the dimensions of the work and want to achieve and improve alignment. This book presents the "Language of Work" model…

  6. Optical alignment of Centaur's inertial guidance system

    NASA Technical Reports Server (NTRS)

    Gordan, Andrew L.

    1987-01-01

    During Centaur launch operations the launch azimuth of the inertial platform's U-accelerometer input axis must be accurately established and maintained. This is accomplished by using an optically closed loop system with a long-range autotheodolite whose line of sight was established by a first-order survey. A collimated light beam from the autotheodolite intercepts a reflecting Porro prism mounted on the platform azimuth gimbal. Thus, any deviation of the Porro prism from its predetermined heading is optically detected by the autotheodolite. The error signal produced is used to torque the azimuth gimbal back to its required launch azimuth. The heading of the U-accelerometer input axis is therefore maintained automatically. Previously, the autotheodolite system could not distinguish between vehicle sway and rotational motion of the inertial platform unless at least three prisms were used. One prism was mounted on the inertial platform to maintain azimuth alignment, and two prisms were mounted externally on the vehicle to track sway. For example, the automatic azimuth-laying theodolite (AALT-SV-M2) on the Saturn vehilce used three prisms. The results of testing and modifying the AALT-SV-M2 autotheodolite to simultaneously monitor and maintain alignment of the inertial platform and track the sway of the vehicle from a single Porro prism.

  7. 2011 Status of the Automatic Alignment System for the National Ignition Facility

    SciTech Connect

    Wilhelmsen, K; Awwal, A; Burkhart, S; McGuigan, D; Kamm, V M; Leach, R; Lowe-Webb, R; Wilson, R

    2011-07-19

    Automated alignment for the National Ignition Facility (NIF) is accomplished using a large-scale parallel control system that directs 192 laser beams along the 300-m optical path. The beams are then focused down to a 50-micron spot in the middle of the target chamber. The entire process is completed in less than 50 minutes. The alignment system commands 9,000 stepping motors for highly accurate adjustment of mirrors and other optics. 41 control loops per beamline perform parallel processing services running on a LINUX cluster to analyze high-resolution images of the beams and their references. This paper describes the status the NIF automatic alignment system and the challenges encountered as NIF development has transitioned from building the laser, to becoming a research project supporting a 24 hour, 7 day laser facility. NIF is now a continuously operated system where performance monitoring is increasingly more critical for operation, maintenance, and commissioning tasks. Equipment wear and the effects of high energy neutrons from fusion experiments are issues which alter alignment efficiency and accuracy. New sensors needing automatic alignment assistance are common. System modifications to improve efficiency and accuracy are prevalent. Handling these evolving alignment and maintenance needs while minimizing the impact on NIF experiment schedule is expected to be an on-going challenge for the planned 30 year operational life of NIF.

  8. Laser beam control and diagnostic systems for the copper-pumped dye laser system at Lawrence Livermore National Laboratory

    SciTech Connect

    Bliss, E.S.; Peterson, R.L.; Salmon, J.T.; Thomas, R.A.

    1992-11-01

    The laser system described in the previous paper is used for experiments in which success requires tight tolerances on beam position, direction, and wavefront. Indeed, the optimum performance of the laser itself depends on careful delivery of copper laser light to the dye amplifiers, precise propagation of dye laser beams through restricted amplifier apertures, and accurate monitoring of laser power at key locations. This paper describes the alignment systems, wavefront correction systems, and laser diagnostics systems which ensure that the control requirements of both the laser and associated experiments are met. Because laser isotope separation processes utilize more than one wavelength, these systems monitor and control multiple wavelengths simultaneously.

  9. High-intracavity-power thin-disk laser for the alignment of molecules.

    PubMed

    Deppe, Bastian; Huber, Günter; Kränkel, Christian; Küpper, Jochen

    2015-11-01

    We propose a novel approach for strong alignment of gas-phase molecules for experiments at arbitrary repetition rates. A high-intracavity-power continuous-wave laser will provide the necessary ac electric field of 10(10)-10(11) W/cm(2). We demonstrate thin-disk lasers based on Yb:YAG and Yb:Lu(2)O(3) in a linear high-finesse resonator providing intracavity power levels in excess of 100 kW at pump power levels on the order of 50 W. The multi-longitudinal-mode operation of this laser avoids spatial-hole burning even in a linear standing-wave resonator. The system will be scaled up as in-vacuum system to allow for the generation of fields of 10(11) W/cm(2). This system will be directly applicable for experiments at modern X-ray light sources, such as synchrotrons or free-electron lasers, which operate at various very high repetition rates. This would allow to record molecular movies through temporally resolved diffractive imaging of fixed-in-space molecules, as well as the spectroscopic investigation of combined X-ray-NIR strong-field effects of atomic and molecular systems. PMID:26561120

  10. Shape and alignment measurement of the heliostat by laser deflectometry

    NASA Astrophysics Data System (ADS)

    Xu, Wenbin; Lu, Zhenwu; Liu, Hua; Zhang, Hongxin; Ni, Zhengguo

    2008-08-01

    In the solar tower thermal power generation system, the precision of the slope angle of the heliostat is the major factor, which influences the efficiency of the system, consequently, this angle should be tested accurately. In this paper, the methods based on laser deflectometry are proposed to measure the shape error of the mirror facet and the connected error of the facets; such apparatus and corresponding software packages are developed. With the help of these two apparatus, the heliostat of 1002, consisting of 55 mirror facets of 1.8182 m2; (hexagon), for the 1MWe solar tower power plant in Beijing are measured and connected successfully.

  11. Optical alignment and tuning system for the HUST THz-FEL

    NASA Astrophysics Data System (ADS)

    Liu, Xu; Liu, Kaifeng; Qin, Bin; Tan, Ping; Fu, Qiang; Wang, Wei; Pei, Yuanji

    2016-11-01

    A compact FEL oscillator with a radiation wavelength of 30 - 100 μm is proposed by HUST and NSRL. The optical cavity is very sensitive to misalignment errors of the mirror, due to its near-concentric and symmetric structure. The magnetic axis of the undulator, the optical axis of the resonator, and the electron beam propagation axis must all be aligned with high precision for achieving saturated lasing. This paper introduces a high-precision, multi-degree-of-freedom controlled optical alignment system, which has the ability to align in the transverse and longitudinal directions. The alignment tolerances are given by theoretical analysis and numerical simulations with three-dimensional FEL code GENESIS and optical propagation code (OPC). To accomplish optical alignment, two auxiliary HeNe laser systems were introduced. By adjusting the HeNe laser beam spot on the wedge, the optical axis can be aligned to the magnetic axis, and the estimated errors meet the tolerances. Finally, the electron beam will be guided through the hole in the central wedge to complete the transverse alignment. The longitudinal alignment and tuning methods are also described.

  12. Microcapillary sign of flap alignment in femtosecond laser-assisted in situ keratomileusis

    PubMed Central

    Fawzy, Fathy; Wahba, Sherine S; Fawzy, Nader

    2016-01-01

    We present an observational sign that ensures perfect alignment during femtosecond laser-assisted in situ keratomileusis (FS LASIK). Alignment is assured when a microsponge is used to dry the flap and the area of dryness exceeds the area of direct touch of the microsponge. The area might even reach the whole circumference of the flap at the first touch. This sign of alignment can be explained by microcapillary action. This sign was not elicited in flaps created by a microkeratome. PMID:27799731

  13. A confocal microscope position sensor for micron-scale target alignment in ultra-intense laser-matter experiments.

    PubMed

    Willis, Christopher; Poole, Patrick L; Akli, Kramer U; Schumacher, Douglass W; Freeman, Richard R

    2015-05-01

    A diagnostic tool for precise alignment of targets in laser-matter interactions based on confocal microscopy is presented. This device permits precision alignment of targets within the Rayleigh range of tight focusing geometries for a wide variety of target surface morphologies. This confocal high-intensity positioner achieves micron-scale target alignment by selectively accepting light reflected from a narrow range of target focal planes. Additionally, the design of the device is such that its footprint and sensitivity can be tuned for the desired chamber and experiment. The device has been demonstrated to position targets repeatably within the Rayleigh range of the Scarlet laser system at The Ohio State University, where use of the device has provided a marked increase in ion yield and maximum energy.

  14. A confocal microscope position sensor for micron-scale target alignment in ultra-intense laser-matter experiments

    NASA Astrophysics Data System (ADS)

    Willis, Christopher; Poole, Patrick L.; Akli, Kramer U.; Schumacher, Douglass W.; Freeman, Richard R.

    2015-05-01

    A diagnostic tool for precise alignment of targets in laser-matter interactions based on confocal microscopy is presented. This device permits precision alignment of targets within the Rayleigh range of tight focusing geometries for a wide variety of target surface morphologies. This confocal high-intensity positioner achieves micron-scale target alignment by selectively accepting light reflected from a narrow range of target focal planes. Additionally, the design of the device is such that its footprint and sensitivity can be tuned for the desired chamber and experiment. The device has been demonstrated to position targets repeatably within the Rayleigh range of the Scarlet laser system at The Ohio State University, where use of the device has provided a marked increase in ion yield and maximum energy.

  15. Microwave systems analysis, solar power satellite. [alignment of the antenna array

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Various alternative active approaches to achieving aand maintaining flatness for the microwave power transmission system (MPTS) were studied. A baseline active alignment scheme was developed which includes subarray attachment mechanisms, height and tilting adjustments, service corridors, a rotating laser beam reference system, monopulse pointing techniques, and the design of a beam-centering photoconductive sensor.

  16. Design process for NIF laser alignment and beam diagnostics

    SciTech Connect

    Grey, A., LLNL

    1998-06-09

    In a controller for an adaptive optic system designed to correct phase aberrations in a high power laser, the wavefront sensor is a discrete Hartmann-Shack design. It uses an army of lenslets (like a fly` s eye) to focus the laser into 77 spots on a CCD camera. Average local tilt of the wavefront across each lenslet changes the position of its focal spot. The system requires 0.1 pixel accuracy in determining the focal spot location. We determine a small area around each spot` s previous location. Within this area, we calculate the centroid of the light intensity in x and y. This calculation fails if the spot regions overlap. Especially during initial acquisition of a highly distorted beam, distinguishing overlapping spots is difficult. However, low resolution analysis of the overlapping spots allows the system to estimate their positions. With this estimate, it can use the deformable mirror to correct the beam enough so we can detect the spots using conventional image processing.

  17. Optimization of field-free molecular alignment by phase-shaped laser pulses

    SciTech Connect

    Hertz, E.; Rouzee, A.; Guerin, S.; Lavorel, B.; Faucher, O.

    2007-03-15

    We theoretically demonstrate the optimization of field-free molecular alignment by phase-shaped femtosecond laser pulses. The effect is assessed in O{sub 2} at T=60 K under realistic conditions of intensity and pulse shaping. The spectral laser phase is sampled through 128 control parameters and a self-learning evolutionary algorithm combined with a nonperturbative regime calculation is used in order to design the specific phase that maximizes the degree of alignment. The postpulse molecular alignment appears significantly enhanced compared to a Fourier-transform-limited pulse of same energy. The analysis of the target state reveals that the solution is close to the optimal one.

  18. Ultrafast laser orthogonal alignment and patterning of carbon nanotube-polymer composite films

    NASA Astrophysics Data System (ADS)

    Murphy, Ryan D.; Abere, Michael J.; Zhang, Huanan; Sun, Haiping; Torralva, Ben; Mansfield, John F.; Kotov, Nicholas A.; Yalisove, Steven M.

    2012-11-01

    Dual orthogonal alignment of carbon nanotubes (CNTs) within the plane and perpendicular to a substrate is essential for many applications but difficult to obtain. Here, we demonstrate that it is possible using a combination of layer-by-layer deposition and ultrafast laser irradiation. Single-wall CNT-polymer composites preferentially aligned within the plane are irradiated with ultrafast laser pulses. After irradiation with distinct fluences at ambient conditions, morphology is seen where CNTs are formed into bundled CNTs with some orthogonal alignment. A model is presented to account for thermal expansion of the polymer and the formation of CNT bundles.

  19. Laser material processing system

    DOEpatents

    Dantus, Marcos

    2015-04-28

    A laser material processing system and method are provided. A further aspect of the present invention employs a laser for micromachining. In another aspect of the present invention, the system uses a hollow waveguide. In another aspect of the present invention, a laser beam pulse is given broad bandwidth for workpiece modification.

  20. Liquid crystal near-IR laser beam shapers employing photoaddressable alignment layers for high-peak-power applications

    NASA Astrophysics Data System (ADS)

    Marshall, Kenneth L.; Saulnier, Debra; Xianyu, Haiqing; Serak, Svetlana; Tabiryan, Nelson

    2013-09-01

    Large-scale, high-energy Nd:glass laser systems require beam shapers to control the spatial distribution of the incident intensity. Commercially available liquid crystal (LC) electro-optical spatial light modulators (SLM's) are frequently employed for this purpose, but their intrinsic requirement for conductive metal or metal-oxide coatings limits their 1054-nm laser-damage thresholds to 230 mJ/cm2 (2.4 ns, 5 Hz), relegating them for use only in low-fluence areas of the laser system. Previously, we demonstrated that passive near-IR LC beam shapers employing coumarin alignment layers patterned by contact photolithography are capable of high resolution and contrast and can withstand incident 1054-nm laser-fluence levels of <30 J/cm2 (1-ns pulse). An evolutionary step to expand the scope of this simple and robust device would be to identify and incorporate into the device structure photoalignment layers that trigger LC bulk reorientation by undergoing reversible optical switching between two predetermined alignment patterns using low-energy polarized UV/visible incident light and have a high near-IR laser-damage threshold. Such "optically driven" LC beam shapers offer the in-system write/erase flexibility of the electro-optical LC SLM's while eliminating conductive coatings that compromise the laser-damage threshold and electrical interconnects that increase device fragility and complexity. To this end, we have recently identified and evaluated the 1054-nm laser-damage-resistance and coating properties of several commercial azobenzene-based photoswitchable alignment materials. In 1-on-1 and N-on-1 testing, these new materials displayed 1054-nm laser-damage thresholds that compare very favorably to those of previously tested coumarin photoalignment materials (30 to 60 J/cm2).

  1. Laser cutting system

    SciTech Connect

    Dougherty, Thomas J

    2015-03-03

    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

  2. ALINET: neural net automatic alignment of high-energy laser resonator optical elements

    NASA Astrophysics Data System (ADS)

    Hart, George A.; Bailey, Adam W.; Palumbo, Louis J.; Kuperstein, Michael

    1993-10-01

    A novel neural net approach has successfully solved the time consuming practical problem of aligning the many optical elements used in the resonator of high power chemical lasers. Moreover, because the neural net can achieve optimal performance in only 2 - 4 steps, as compared with 50 for other techniques, the important ability to effect real time control is gained. This represents a significant experimental breakthrough because of the difficulty previously associated with this alignment process. Use of either near or far field image information produces excellent performance. The method is very robust in the presence of noise. For cases where the initial misalignment falls outside the regime encompassed by the training set, a hybrid approach utilizing an advanced conventional method can bring the optical system within the capture range of the neural net. This reported use of a neural net to rapidly convert imagery information into high precision control information is of broad applicability to optical, acoustic, or electromagnetic alignment, positioning, and control problems.

  3. Super growth of vertically aligned carbon nanotubes on pulsed laser deposited catalytic thin films

    NASA Astrophysics Data System (ADS)

    Fejes, D.; Pápa, Z.; Kecsenovity, E.; Réti, B.; Toth, Z.; Hernadi, K.

    2015-03-01

    Efficient and reproducible growth of vertically aligned carbon nanotube (CNT) forests by catalytic chemical vapor deposition (CVD) requires precise setting of the properties of the catalyst thin films and CVD conditions. In this work, super growth of vertically aligned CNTs onto Al2O3 support and Fe-Co catalyst layer system is presented. The layers were grown by pulsed laser deposition (PLD) onto silicon wafer pieces. Their thickness and optical properties were controlled by spectroscopic ellipsometry. The effect of heat treatment at 750 °C in nitrogen and in hydrogen of these PLD layers was compared. High-resolution electron microscopic images showed that treatment of catalyst layers in H2 resulted in finer and denser catalytic particles. As a result, well-aligned, dense and few-walled CNT forests with 1-1.5 mm height were deposited by water-vapor-assisted CVD on the hydrogen-treated films, while without hydrogen treatment defected CNT structures were grown. According to these observations, Raman spectroscopy showed a higher degree of crystallinity in case of CNT-s, where reduction by hydrogen influenced the oxidation state of the metallic catalytic particles in a beneficial way.

  4. Mounting, alignment and integration of large optics in China's high power laser

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Xiong, Zhao; Yuan, Xiaodong

    2016-05-01

    SG-III, a high-power laser facility of China, is constructed to produce 0.18MJ energy for physical experiments under controlled laboratory conditions. Each laser beam requires the ability to align to a millimeter-sized target with a precision of 30 μm (RMS) and the single-beam energy will be up to 3.75 KJ. Arrayed along each beam-path, hundreds of optics must be positioned to stringent tolerances. Therefore, this paper introduces the approaches used by engineers to overcome the technical challenges on precise mounting, alignment and integration of large optics in china's high power laser facility.

  5. Shear alignment of lamellar mesophase systems

    NASA Astrophysics Data System (ADS)

    Jaju, S. J.; Kumaran, V.

    2015-11-01

    Mixtures of oil, water and surfactants form different microphases. Some of these phases, e.g. lamellar, hexagonal phases, lead to complex rheological behaviour at macroscale due to inherent anisotropy and irregularities in the microstructures. We present a comprehensive simulation study to examine the structure-rheology relationship in lamellar phase flow. At mesoscale, Reynolds number (Re), Schmidt number (Sc), Ericksen number (Er), extent of segregation between hydrophilic and hydrophobic components (r), ratio of viscosity of the two components (Δμ /μ0), and system size to layer width ratio (L / λ) complete the lamellar phase description. We have used lattice Boltzmann simulations to study a two dimensional lamellar phase system of moderate size. The domains and grain boundaries seen at low Sc are replaced by isolated edge dislocations at high Sc. The alignment mechanism does not change with changes in layer bending moduli (Er), viscosity contrast or r. Increasing segregation, increases disorder; this however does not lead to higher resistance to flow. At high Er, the shear tries homogenise the concentration field and disrupt layer formation. We see significantly higher peak viscosity at low Er at high viscosity contrast and due to defect pinning. The authors would like to thank the Department of Science and Technology, Government of India for financial support, and Supercomputer Education and Research Centre at Indian Institute of Science for the computational resources.

  6. Infrared laser system

    DOEpatents

    Cantrell, Cyrus D.; Carbone, Robert J.; Cooper, Ralph

    1982-01-01

    An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture.

  7. Infrared laser system

    DOEpatents

    Cantrell, Cyrus D.; Carbone, Robert J.; Cooper, Ralph S.

    1977-01-01

    An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture.

  8. Alignment of the ATLAS inner detector tracking system

    NASA Astrophysics Data System (ADS)

    Kollár, Daniel; ATLAS Collaboration

    2010-04-01

    The Large Hadron Collider (LHC) at CERN is the world's largest particle accelerator. ATLAS is one of the two general purpose experiments. The inner tracking system of ATLAS, the Inner Detector, is built on two technologies: silicon detectors and drift tube based detectors. The required precision for the alignment of the most sensitive coordinates of the Silicon sensors is just a few microns. Therefore the alignment of the ATLAS Inner Detector is performed using complex algorithms requiring extensive CPU and memory usage. The proposed alignment algorithms were exercised on several applications. This proceedings present the outline of the alignment approach and results from Cosmic Ray runs and large scale computing simulation of physics samples mimicking the ATLAS operation during real data-taking. The full alignment chain was tested using these samples and alignment constants were produced and validated within 24 hours. Early alignment of the ATLAS Inner Detector is provided even before the LHC start up by analysing Cosmic Ray data.

  9. Object oriented software for simulation and reconstruction of big alignment systems

    NASA Astrophysics Data System (ADS)

    Arce, P.

    2003-04-01

    Modern high-energy physics experiments require tracking detectors to provide high precision under difficult working conditions (high magnetic field, gravity loads and temperature gradients). This is the reason why several of them are deciding to implement optical alignment systems to monitor the displacement of tracking elements in operation. To simulate and reconstruct optical alignment systems a general purpose software, named COCOA, has been developed, using the object oriented paradigm and software engineering techniques. Thanks to the big flexibility in its design, COCOA is able to reconstruct any optical system made of a combination of the following objects: laser, x-hair laser, incoherent source—pinhole, lens, mirror, plate splitter, cube splitter, optical square, rhomboid prism, 2D sensor, 1D sensor, distance-meter, tilt-meter, user-defined. COCOA was designed to satisfy the requirements of the CMS alignment system, which has several thousands of components. Sparse matrix techniques had been investigated for solving non-linear least squares fits with such a big number of parameters. The soundness of COCOA has already been stressed in the reconstruction of the data of a full simulation of a quarter plane of the CMS muon alignment system, which implied solving a system of 900 equations with 850 unknown parameters. Full simulation of the whole CMS alignment system, with over 30,000 parameters, is quite advanced. The integration of COCOA in the CMS software framework is also under progress.

  10. Cost-efficient hermetic fibre pigtailed laser module utilizing passive device alignment on an LTCC substrate

    NASA Astrophysics Data System (ADS)

    Keränen, K.; Ollila, J.; Mäkinen, J.-T.; Kautio, K.; Korhonen, P.; Heikkinen, V.; Väätäinen, O.; Heilala, J.; Karioja, P.

    2006-04-01

    A hermetic fibre pigtailed laser module utilizing passive device alignment on a low temperature co-fired ceramics (LTCC) substrate is demonstrated. The 3-dimensional shape of the laminated and fired ceramic substrate provides the necessary alignment structures including holes, grooves and cavities for the laser to fibre coupling. The achieved passive alignment accuracy allows high coupling efficiency realizations of multi-mode fibre pigtailed laser modules. The ceramic substrate is intrinsically hermetic and it opens up a possibility to produce cost efficient hermetic packaging. In our concept hermetic sealing is produced by utilizing Kovar frame, which is soldered to an LTCC substrate. Kovar frame has a hole for fibre feed-trough and a hermetic glass-metal sealing between fibre and frame is processed using glass preform. The heart of the module is a power laser diode chip, which can produce several watts of continuous power. The module, however, can be finally used as a transmitter in a laser pulse time-of-flight distance sensor and in this application it can be overdriven by a factor of 10. This means that the peak optical power in the pulses can be several tens of watts. The laser chip allows this kind of overdriving due to the fact that the duty factor in the operation is only 0.0001 at 2 kHz pulsing frequency. Optical coupling efficiency of the multi-mode laser system was simulated using optical systems simulation software. The nominal coupling efficiency between 210 μm x 1μm stripe laser and 200/220 μm step index fibre (NA=0.22) was 0.65. The simulated coupling efficiency was verified by prototype realization and characterization. The measured average coupling efficiency of the hermetically sealed prototypes was 0.39. The coupling efficiencies of prototypes varied from 0.14 to 0.64. Leak rate of 1 x 10 -7 [atm x cm 3/s] was measured in the helium leak tests for the final prototype module, when the module was tested according to MIL-STD-883D method 1014

  11. Underwater laser system

    NASA Astrophysics Data System (ADS)

    Kushina, Mark E.; Heberle, Geoff; Hope, Michael; Crittenden, Ryan M.; Bethel, Michael

    2002-03-01

    We have developed a solid-state laser operating at 532nm for underwater topographic investigations. The laser system is integrated into a torpedo-like 'towed-body', with the military designation of AQS-20. This laser, along with other sophisticated receiver opto-electronic systems enables detailed underwater bathymetry. CEO designed and manufactured the laser portion of this system. The laser sub-system is comprised of two separate parts: the LTU (Laser Transmitter Unit) and the LEU (Laser Electronics Unit). The LTU and LEU where put through Mil-standard testing for vibration, shock and temperature storage and operation extremes as well as Mil-461C EMI/EMC testing. The Nd:YAG laser operates at a 400 Hz pulse repetition frequency and is controlled remotely, tethered to the system controller in a ship or helicopter. Power monitor circuits allow real time laser health monitoring, which enables input parameter adjustments for consistent laser behavior. The towed body moves forward at a constant rate of speed while this underwater LIDAR system gathers data. All heat generated must be conducted into the outer hull of the towed-body and then, to the surrounding ambient ocean water. The water temperature may vary from 0-35 degrees C.

  12. Field-free molecular alignment induced by elliptically polarized laser pulses: Noninvasive three-dimensional characterization

    SciTech Connect

    Hertz, E.; Guerin, S.; Jauslin, H. R.; Lavorel, B.; Faucher, O.; Daems, D.

    2007-10-15

    An investigation of field-free molecular alignment produced by elliptically polarized laser pulses is reported. Experiments are conducted in CO{sub 2} at room temperature. A noninvasive all-optical technique, based on the cross defocusing of a probe pulse, is used to measure the alignment along two orthogonal directions which is sufficient to provide a three-dimensional characterization. The field-free molecular alignment produced by a laser of elliptical polarization is in good agreement in terms of amplitude and shape with theoretical predictions. It turns out to be almost equivalent to the superposition of the effects that one would obtain with two individual cross-polarized pulses. The investigation highlights notably the occurrence of field-free two-direction alignment alternation for a suitably chosen degree of ellipticity. The analogy between this specific ellipticity and the well-known 'magic angle' used in time-resolved spectroscopy to prevent rotational contributions is discussed.

  13. Laser rocket system analysis

    NASA Technical Reports Server (NTRS)

    Jones, W. S.; Forsyth, J. B.; Skratt, J. P.

    1979-01-01

    The laser rocket systems investigated in this study were for orbital transportation using space-based, ground-based and airborne laser transmitters. The propulsion unit of these systems utilizes a continuous wave (CW) laser beam focused into a thrust chamber which initiates a plasma in the hydrogen propellant, thus heating the propellant and providing thrust through a suitably designed nozzle and expansion skirt. The specific impulse is limited only by the ability to adequately cool the thruster and the amount of laser energy entering the engine. The results of the study showed that, with advanced technology, laser rocket systems with either a space- or ground-based laser transmitter could reduce the national budget allocated to space transportation by 10 to 345 billion dollars over a 10-year life cycle when compared to advanced chemical propulsion systems (LO2-LH2) of equal capability. The variation in savings depends upon the projected mission model.

  14. Field-Free Two-Direction Alignment Alternation of Linear Molecules by Elliptic Laser Pulses

    SciTech Connect

    Daems, D.; Guerin, S.; Hertz, E.; Jauslin, H.R.; Lavorel, B.; Faucher, O.

    2005-08-05

    We show that a linear molecule subjected to a short specific elliptically polarized laser field yields postpulse revivals exhibiting alignment alternatively located along the orthogonal axis and the major axis of the ellipse. The effect is experimentally demonstrated by measuring the optical Kerr effect along two different axes. The conditions ensuring an optimal field-free alternation of high alignments along both directions are derived.

  15. Polarization-selective alignment of a carbon nanotube film by using femtosecond laser ablation

    NASA Astrophysics Data System (ADS)

    Choi, S. B.; Byeon, C. C.; Park, D. J.; Jeong, M. S.

    2016-01-01

    We report on a considerable alignment of single-walled carbon nanotubes (SWCNTs) in randomly oriented bundles, by using a simple drop-and-dry method and irradiation with high-intensity femtosecond laser pulses. A remarkable third-harmonic generation was observed after irradiation with the laser pulses, whereas a narrow-band white-light continuum was generated in the as-prepared films. This observation, combined with scanning electron microscopy images, confirmed the high degree of alignment of the SWCNTs. In contrast to the pulsed irradiation of carbon soot, the powerdependent laser irradiation of a highly-purified SWCNT film show polarization-dependent ablation of individual nanotubes caused by polarization-dependent absorption. Raman spectroscopy results confirmed the presence of fractured nanotubes caused by the ablation processes. Polarizationresolved absorption spectroscopy results revealed that the aligned SWCNT film had potential usage in optical polarizers.

  16. Intense laser alignment in dissipative media as a route to solvent dynamics.

    PubMed

    Ramakrishna, S; Seideman, Tamar

    2005-09-01

    We extend the concept of alignment by short intense pulses to dissipative environments within a density matrix formalism and illustrate the application of this method as a probe of the dissipative properties of dense media. In particular, we propose a means of disentangling rotational population relaxation from decoherence effects via strong laser alignment. We illustrate also the possibility of suppressing rotational relaxation to prolong the alignment lifetime through choice of the field parameters. Implications to several disciplines and a number of potential applications are proposed.

  17. Intense Laser Alignment in Dissipative Media as a Route to Solvent Dynamics

    SciTech Connect

    Ramakrishna, S.; Seideman, Tamar

    2005-09-09

    We extend the concept of alignment by short intense pulses to dissipative environments within a density matrix formalism and illustrate the application of this method as a probe of the dissipative properties of dense media. In particular, we propose a means of disentangling rotational population relaxation from decoherence effects via strong laser alignment. We illustrate also the possibility of suppressing rotational relaxation to prolong the alignment lifetime through choice of the field parameters. Implications to several disciplines and a number of potential applications are proposed.

  18. Strong visible light emission from well-aligned multiwalled carbon nanotube films under infrared laser irradiation

    SciTech Connect

    Zhang Yong; Gong Tao; Liu Wenjin; Zhang Xianfeng; Chang Jianguo; Wang Kunlin; Wu Dehai

    2005-10-24

    We report strong and brilliant visible light emission from well-aligned multiwalled carbon nanotube (AMWNT) films under infrared (IR) laser irradiation with wavelength at 1.06 and 10.6 {mu}m, respectively. The AMWNT film shows a high durability against laser irradiation and achieved a conversion from IR laser to visible light. It is a good candidate for optical converter. Light emission spectra versus different wavelengths and various powers were found to have similar line shapes. It could be explained as combination of laser-induced photoluminescence and resistive heating.

  19. Compact-range coordinate system established using a laser tracker.

    SciTech Connect

    Gallegos, Floyd H.; Bryce, Edwin Anthony

    2006-12-01

    Establishing a Cartesian coordinate reference system for an existing Compact Antenna Range using the parabolic reflector is presented. A SMX (Spatial Metrix Corporation) M/N 4000 laser-based coordinate measuring system established absolute coordinates for the facility. Electric field characteristics with positional movement correction are evaluated. Feed Horn relocation for alignment with the reflector axis is also described. Reference points are established for follow-on non-laser alignments utilizing a theodolite.

  20. Alignment enhancement of molecules embedded in helium nanodroplets by multiple laser pulses

    NASA Astrophysics Data System (ADS)

    Christiansen, Lars; Nielsen, Jens H.; Pentlehner, Dominik; Underwood, Jonathan G.; Stapelfeldt, Henrik

    2015-11-01

    We show experimentally that field-free one-dimensional (1D) alignment of 1,4-diiodobenzene molecules embedded in helium nanodroplets, induced by a single, linearly polarized 200-fs laser pulse, can be significantly enhanced by using two or four optimally synchronized laser pulses. The strongest degree of 1D alignment is obtained with four pulses and gives >0.60 . Besides the immediate implications for molecular frame studies, our results pave the way for more general manipulation of rotational motion of molecules in He droplets.

  1. Using a laser tracker for active alignment on the Large Binocular Telescope

    NASA Astrophysics Data System (ADS)

    Rakich, A.

    2012-09-01

    The Large Binocular Telescope (LBT) currently achieves collimation using a combination of collimation models and closed-loop active correction schemes. Shack Hartmann wavefront sensors with off-axis guide stars are used for Gregorian modes, and a closed-loop correction scheme is used for the prime-focus cameras. While in general this combination serves to produce alignment residuals well below a good seeing limit within a few minutes of obtaining a given target field, the uniquely asymmetrical structure of the LBT is prone to producing large deflections of the telescope optics when the ambient temperature is changing unusually rapidly. These deflections are difficult to model satisfactorily, and are an ongoing source of inefficiency in telescope operations. Furthermore, none of the current approaches to telescope collimation are particularly "piston aware"; a situation that needs to be improved on now that the LBT is commencing operations with the first of its beam combining instruments, LBTI. The laser tracker is a metrology instrument capable of automatically measuring optical element positions with better than 100 micron precision within a spherical volume of 30 m radius centered on the tracker head. With the ability to directly measure optics into position to this accuracy built into the Telescope Control System (TCS), the LBT would always be starting observations from a point of near-collimation, the component telescopes would be co-pointed, and the OPD would be well within the capture range of the beam combining instrument's internal phasing systems. This paper describes first results from engineering investigations into using the laser tracker to automatically align the optics on the LBT.

  2. A comparative study of two different clear aligner systems

    PubMed Central

    2014-01-01

    Background This study aims to compare the ‘Nuvola®’ system with ‘Fantasmino®’ system, examine their material properties, and define the indications for use of the aligners. Methods Two groups of patients were selected and were respectively treated with Nuvola® aligner and Fantasmino® system. Results The goal of treatment has been achieved with the two systems. Conclusions The two types of aligners have shown differences during the treatment. Fantasmino® system has elastic properties of high performance, but its size does not encourage compliance throughout the day. Nuvola® system determines good tooth movement and its size facilitates the patient’s collaboration. In both aligner systems, difficulties were found in the correction of torque information and rotations. PMID:24934094

  3. Fully automated hybrid diode laser assembly using high precision active alignment

    NASA Astrophysics Data System (ADS)

    Böttger, Gunnar; Weber, Daniel; Scholz, Friedemann; Schröder, Henning; Schneider-Ramelow, Martin; Lang, Klaus-Dieter

    2016-03-01

    Fraunhofer IZM, Technische Universität Berlin and eagleyard Photonics present various implementations of current micro-optical assemblies for high quality free space laser beam forming and efficient fiber coupling. The laser modules shown are optimized for fast and automated assembly in small form factor packages via state-of-the-art active alignment machinery, using alignment and joining processes that have been developed and established in various industrial research projects. Operational wavelengths and optical powers ranging from 600 to 1600 nm and from 1 mW to several W respectively are addressed, for application in high-resolution laser spectroscopy, telecom and optical sensors, up to the optical powers needed in industrial and medical laser treatment.

  4. The Geoscience Laser Altimeter System Laser Transmitter

    NASA Technical Reports Server (NTRS)

    Afzal, R. S.; Dallas, J. L.; Yu, A. W.; Mamakos, W. A.; Lukemire, A.; Schroeder, B.; Malak, A.

    2000-01-01

    The Geoscience Laser Altimeter System (GLAS), scheduled to launch in 2001, is a laser altimeter and lidar for tile Earth Observing System's (EOS) ICESat mission. The laser transmitter requirements, design and qualification test results for this space- based remote sensing instrument are presented.

  5. The Poisson alignment reference system implementation at the Advanced Photon Source.

    SciTech Connect

    Feier, I.

    1998-09-21

    The Poisson spot was established using a collimated laser beam from a 3-mW diode laser. It was monitored on a quadrant detector and found to be very sensitive to vibration and air disturbances. Therefore, for future work we strongly recommend a sealed vacuum tube in which the Poisson line may be propagated. A digital single-axis feedback system was employed to generate an straight line reference (SLR) on the X axis. Pointing accuracy was better than 8 {+-} 2 microns at a distance of 5 m. The digital system was found to be quite slow with a maximum bandwidth of 47 {+-} 9 Hz. Slow drifts were easily corrected but any vibration over 5 Hz was not. We recommend an analog proportional-integral-derivative (PID) controller for high bandwidth and smooth operation of the kinematic mirror. Although the Poisson alignment system (PAS) at the Advanced Photon Source is still in its infancy, it already shows great promise as a possible alignment system for the low-energy undulator test line (LEUTL). Since components such as wigglers and quadruples will initially be aligned with respect to each other using conventional means and mounted on some kind of rigid rail, the goal would be to align six to ten such rails over a distance of about 30 m. The PAS could be used to align these rails by mounting a sphere at the joint between two rails. These spheres would need to be in a vacuum pipe to eliminate the refractive effects of air. Each sphere would not be attached to either rail but instead to a flange connecting the vacuum pipes of each rail. Thus the whole line would be made up of straight, rigid segments that could be aligned by moving the joints. Each sphere would have its own detector, allowing the operators to actively monitor the position of each joint and therefore the overall alignment of the system.

  6. Evaluation of Laser Based Alignment Algorithms Under Additive Random and Diffraction Noise

    SciTech Connect

    McClay, W A; Awwal, A; Wilhelmsen, K; Ferguson, W; McGee, M; Miller, M

    2004-09-30

    The purpose of the automatic alignment algorithm at the National Ignition Facility (NIF) is to determine the position of a laser beam based on the position of beam features from video images. The position information obtained is used to command motors and attenuators to adjust the beam lines to the desired position, which facilitates the alignment of all 192 beams. One of the goals of the algorithm development effort is to ascertain the performance, reliability, and uncertainty of the position measurement. This paper describes a method of evaluating the performance of algorithms using Monte Carlo simulation. In particular we show the application of this technique to the LM1{_}LM3 algorithm, which determines the position of a series of two beam light sources. The performance of the algorithm was evaluated for an ensemble of over 900 simulated images with varying image intensities and noise counts, as well as varying diffraction noise amplitude and frequency. The performance of the algorithm on the image data set had a tolerance well beneath the 0.5-pixel system requirement.

  7. Mask-to-wafer alignment system

    DOEpatents

    Sweatt, William C.; Tichenor, Daniel A.; Haney, Steven J.

    2003-11-04

    A modified beam splitter that has a hole pattern that is symmetric in one axis and anti-symmetric in the other can be employed in a mask-to-wafer alignment device. The device is particularly suited for rough alignment using visible light. The modified beam splitter transmits and reflects light from a source of electromagnetic radiation and it includes a substrate that has a first surface facing the source of electromagnetic radiation and second surface that is reflective of said electromagnetic radiation. The substrate defines a hole pattern about a central line of the substrate. In operation, an input beam from a camera is directed toward the modified beam splitter and the light from the camera that passes through the holes illuminates the reticle on the wafer. The light beam from the camera also projects an image of a corresponding reticle pattern that is formed on the mask surface of the that is positioned downstream from the camera. Alignment can be accomplished by detecting the radiation that is reflected from the second surface of the modified beam splitter since the reflected radiation contains both the image of the pattern from the mask and a corresponding pattern on the wafer.

  8. LEAPS (Laser electro-optical alignment pole for surveying)

    NASA Technical Reports Server (NTRS)

    Caudill, L.

    1973-01-01

    Azimuthal bearing between two obscured points is measured by placing laser beam at one of the points. Beam is directed straight up into the air so that some part of it may be detected from any position a reasonable distance away.

  9. Reconstruction of two-dimensional molecular structure with laser-induced electron diffraction from laser-aligned polyatomic molecules

    SciTech Connect

    Yu, Chao; Wei, Hui; Wang, Xu; Le, Anh -Thu; Lu, Ruifeng; Lin, C. D.

    2015-10-27

    Imaging the transient process of molecules has been a basic way to investigate photochemical reactions and dynamics. Based on laser-induced electron diffraction and partial one-dimensional molecular alignment, here we provide two effective methods for reconstructing two-dimensional structure of polyatomic molecules. We demonstrate that electron diffraction images in both scattering angles and broadband energy can be utilized to retrieve complementary structure information, including positions of light atoms. Lastly, with picometre spatial resolution and the inherent femtosecond temporal resolution of lasers, laser-induced electron diffraction method offers significant opportunities for probing atomic motion in a large molecule in a typical pump-probe measurement.

  10. Damped and thermal motion of large, laser-aligned molecules in droplet beams

    SciTech Connect

    Starodub, D; Doak, B; Schmidt, K; Weierstall, U; Wu, J; Spence, J; Howells, M; Marcus, M; Shapiro, D; Barty, A; Chapman, H

    2005-09-29

    We consider a monodispersed Rayleigh droplet beam of water droplets doped with proteins. An intense infrared laser is used to align these droplets. The arrangement has been proposed for electron and X-ray diffraction studies of proteins which are difficult to crystallize. This paper considers the effect of thermal fluctuations on the angular spread of alignment in thermal equilibrium, and relaxation phenomena, particularly the damping of oscillations excited as the molecules enter the field. The possibility of adiabatic alignment is also considered. We find that damping times in high pressure gas cell as used in X-ray diffraction experiments are short compared to the time taken for molecules to traverse the beam, and that a suitably shaped field might be used for electron diffraction experiments in vacuum to provide adiabatic alignment, thus obviating the need for a damping gas cell.

  11. Damped and thermal motion of laser-aligned hydrated macromolecule beams for diffraction.

    PubMed

    Starodub, D; Doak, R B; Schmidt, K; Weierstall, U; Wu, J S; Spence, J C H; Howells, M; Marcus, M; Shapiro, D; Barty, A; Chapman, H N

    2005-12-22

    We consider a monodispersed Rayleigh droplet beam of water droplets doped with proteins. An intense infrared laser is used to align these droplets. The arrangement has been proposed for electron- and x-ray-diffraction studies of proteins which are difficult to crystallize. This paper considers the effect of thermal fluctuations on the angular spread of alignment in thermal equilibrium, and relaxation phenomena, particularly the damping of oscillations excited as the molecules enter the field. The possibility of adiabatic alignment is also considered. We find that damping times in a high-pressure gas cell as used in x-ray-diffraction experiments are short compared with the time taken for molecules to traverse the beam and that a suitably shaped field might be used for electron-diffraction experiments in vacuum to provide adiabatic alignment, thus obviating the need for a damping gas cell.

  12. Alignment of the ATLAS inner detector tracking system

    NASA Astrophysics Data System (ADS)

    Moles-Valls, Regina

    2010-05-01

    The CERN's Large Hadron Collider (LHC) is the world largest particle accelerator. ATLAS (A Toroidal LHC ApparatuS) is one of the two general purpose experiments equipped with a charged particle tracking system built on two technologies: silicon and drift tube based detectors, composing the ATLAS Inner Detector (ID). The alignment of the tracking system poses a challenge as one should solve a linear equation with almost 36 000 degrees of freedom. The required precision for the alignment of the most sensitive coordinates of the silicon sensors is just few microns. This limit comes from the requirement that the misalignment should not worsen the resolution of the track parameter measurements by more than 20%. Therefore the alignment of the ATLAS ID requires complex algorithms with extensive CPU and memory usage. So far the proposed alignment algorithms are exercised on several applications. We will present the outline of the alignment approach and results from Cosmic Ray runs and large scale computing simulation of physics samples mimicking the ATLAS operation during real data taking. For the later application the trigger of the experiment is simulated and the event filter is applied in order to produce an alignment input data stream. The full alignment chain is tested using that stream and alignment constants are produced and validated within 24 h. Cosmic ray data serves to produce an early alignment of the real ATLAS Inner Detector even before the LHC start up. Beyond all tracking information, the assembly survey database contains essential information in order to determine the relative position of one module with respect to its neighbors. Finally a hardware system measuring an array of grid lines in the modules support structure with a Frequency Scan Interferometer monitors short time system deformations.

  13. Rigorous electromagnetic simulation applied to alignment systems

    NASA Astrophysics Data System (ADS)

    Deng, Yunfei; Pistor, Thomas V.; Neureuther, Andrew R.

    2001-09-01

    Rigorous electromagnetic simulation with TEMPEST is used to provide benchmark data and understanding of key parameters in the design of topographical features of alignment marks. Periodic large silicon trenches are analyzed as a function of wavelength (530-800 nm), duty cycle, depth, slope and angle of incidence. The signals are well behaved except when the trench width becomes about 1 micrometers or smaller. Segmentation of the trenches to form 3D marks shows that a segmentation period of 2-5 wavelengths makes the diffraction in the (1,1) direction about 1/3 to 1/2 of that in the main first order (1,0). Transmission alignment marks nanoimprint lithography using the difference between the +1 and -1 reflected orders showed a sensitivity of the difference signal to misalignment of 0.7%/nm for rigorous simulation and 0.5%/nm for simple ray-tracing. The sensitivity to a slanted substrate indentation was 10 nm off-set per degree of tilt from horizontal.

  14. Recent advances in automatic alignment system for the National Iginition Facility

    SciTech Connect

    Wilhelmsen, K; Awwal, A; Kalantar, D; Leach, R; Lowe-Webb, R; McGuigan, D; Kamm, V

    2010-12-08

    The automatic alignment system for the National Ignition Facility (NIF) is a large-scale parallel system that directs all 192 laser beams along the 300-m optical path to a 50-micron focus at target chamber in less than 50 minutes. The system automatically commands 9,000 stepping motors to adjust mirrors and other optics based upon images acquired from high-resolution digital cameras viewing beams at various locations. Forty-five control loops per beamline request image processing services running on a LINUX cluster to analyze these images of the beams and references, and automaticallys teer the beams toward the target. This paper discusses the upgrades to the NIF automatic alignment system to handle new alignment needs and evolving requirements as related to various types of experiments performed. As NIF becomes a continuously-operated system and more experiments are performed, performance monitoring is increasingly important for maintenance and commissioning work. Data, collected during operations, is analyzed for tuning of the laser and targeting maintenance work. handling evolving alignment and maintenance needs is expected for the planned 30-year operational life of NIF.

  15. Experimental investigation on focusing characteristics of a He-Ne laser using circular Fresnel zone plate for high-precision alignment of linear accelerators

    SciTech Connect

    Suwada, Tsuyoshi; Satoh, Masanori; Telada, Souichi; Minoshima, Kaoru

    2012-05-15

    We experimentally investigate the focusing characteristics of a He-Ne laser at the focal region for the high-precision alignment of long-distance linear accelerators using a circular Fresnel zone plate. The laser wave passing through the Fresnel zone plate having a focal length of 66.7 m propagates for a 268-m-long distance at atmospheric pressure. A new laser-based alignment system using Fresnel zone plates as the alignment targets is discussed. The transverse displacement of the focused spot of the laser is measured as a function of the displacement of the target by a detector installed at the focal point. Systematic studies on the focusing characteristics and alignment precision have been successfully conducted in this experiment. The experimental results are in good agreement with theoretical calculations, and the alignment precision of the target is determined to be less than {+-}30 {mu}m. In this study, we perform a detailed experimental investigation on the laser propagation and focusing characteristics using the circular Fresnel zone plate at the focal region along with theoretical calculations.

  16. Diagnostic apparatus and method for use in the alignment of one or more laser means onto a fiber optics interface

    DOEpatents

    Johnson, Steve A.; Shannon, Robert R.

    1987-01-01

    Diagnostic apparatus for use in determining the proper alignment of a plurality of laser beams onto a fiber optics interface is disclosed. The apparatus includes a lens assembly which serves two functions, first to focus a plurality of laser beams onto the fiber optics interface, and secondly to reflect and image the interface using scattered light to a monitor means. The monitor means permits indirect observation of the alignment or focusing of the laser beams onto the fiber optics interface.

  17. Diagnostic apparatus and method for use in the alignment of one or more laser means onto a fiber optics interface

    DOEpatents

    Johnson, S.A.; Shannon, R.R.

    1985-01-18

    Diagnostic apparatus for use in determining the proper alignment of a plurality of laser beams onto a fiber optics interface is disclosed. The apparatus includes a lens assembly which serves two functions, first to focus a plurality of laser beams onto the fiber optics interface, and secondly to reflect and image the interface using scattered light to a monitor means. The monitor means permits indirect observation of the alignment or focusing of the laser beams onto the fiber optics interface.

  18. Stability Measurements for Alignment of the NIF Neutron Imaging System Pinhole Array

    SciTech Connect

    Fittinghoff, D N; Bower, D E; Drury, O B; Dzenitis, J M; Frank, M; Buckles, R A; Munson, C; Wilde, C H

    2011-03-29

    The alignment system for the National Ignition Facility's neutron imaging system has been commissioned and measurements of the relative stability of the 90-315 DIM, the front and the back of the neutron imaging pinhole array and an exploding pusher target have been made using the 90-135 and the 90-258 opposite port alignment systems. Additionally, a laser beam shot from the neutron-imaging Annex and reflected from a mirror at the back of the pinhole array was used to monitor the pointing of the pinhole. Over a twelve hour period, the relative stability of these parts was found to be within {approx} {+-}18 {micro}m rms even when using manual methods for tracking the position of the objects. For highly visible features, use of basic particle tracking techniques found that the front of the pinhole array was stable relative to the 90-135 opposite port alignment camera to within {+-}3.4 {micro}m rms. Reregistration, however, of the opposite port alignment systems themselves using the target alignment sensor was found to change the expected position of target chamber center by up to 194 {micro}m.

  19. A Concept for Zero-Alignment Micro Optical Systems

    SciTech Connect

    DESCOUR, MICHAEL R.; KOLOLUOMA,TERHO; LEVEY,RAVIV; RANTALA,JUHA T.; SHUL,RANDY J.; WARREN,MIAL E.; WILLISON,CHRISTI LEE

    1999-09-16

    We are developing a method of constructing compact, three-dimensional photonics systems consisting of optical elements, e.g., lenses and mirrors, photo-detectors, and light sources, e.g., VCSELS or circular-grating lasers. These optical components, both active and passive, are mounted on a lithographically prepared silicon substrate. We refer to the substrate as a micro-optical table (MOT) in analogy with the macroscopic version routinely used in optics laboratories. The MOT is a zero-alignment, microscopic optical-system concept. The position of each optical element relative to other optical elements on the MOT is determined in the layout of the MOT photomask. Each optical element fits into a slot etched in the silicon MOT. The slots are etched using a high-aspect-ratio silicon etching (HARSE) process. Additional positioning features in each slot's cross-section and complementary features on each optical element permit accurate placement of that element's aperture relative to the MOT substrate. In this paper we present the results of the first fabrication and micro-assembly experiments of a silicon-wafer based MOT. Based on these experiments, estimates of position accuracy are reported. We also report on progress in fabrication of lens elements in a hybrid sol-gel material (HSGM). Diffractive optical elements have been patterned in a 13-micron thick HSGM layer on a 150-micron thick soda-lime glass substrate. The measured ms surface roughness was 20 nm. Finally, we describe modeling of MOT systems using non-sequential ray tracing (NSRT).

  20. Laser multipass system with interior cell configuration

    SciTech Connect

    Borysow, Jacek; Kostinski, Alexander; Fink, Manfred

    2011-10-20

    We ask whether it is possible to restore a multipass system alignment after a gas cell is inserted in the central region. Indeed, it is possible, and we report on a remarkably simple rearrangement of a laser multipass system, composed of two spherical mirrors and a gas cell with flat windows in the middle. For example, for a window of thickness d and refractive index of n, adjusting the mirror separation by approx. 2d(1-1n) is sufficient to preserve the laser beam alignment and tracing. This expression is in agreement with ray-tracing computations and our laboratory experiment. Insofar as our solution corrects for spherical aberrations, it may also find applications in microscopy.

  1. Underwater laser detection system

    NASA Astrophysics Data System (ADS)

    Gomaa, Walid; El-Sherif, Ashraf F.; El-Sharkawy, Yasser H.

    2015-02-01

    The conventional method used to detect an underwater target is by sending and receiving some form of acoustic energy. But the acoustic systems have limitations in the range resolution and accuracy; while, the potential benefits of a laserbased underwater target detection include high directionality, high response, and high range accuracy. Lasers operating in the blue-green region of the light spectrum(420 : 570nm)have a several applications in the area of detection and ranging of submersible targets due to minimum attenuation through water ( less than 0.1 m-1) and maximum laser reflection from estimated target (like mines or submarines) to provide a long range of detection. In this paper laser attenuation in water was measured experimentally by new simple method by using high resolution spectrometer. The laser echoes from different targets (metal, plastic, wood, and rubber) were detected using high resolution CCD camera; the position of detection camera was optimized to provide a high reflection laser from target and low backscattering noise from the water medium, digital image processing techniques were applied to detect and discriminate the echoes from the metal target and subtract the echoes from other objects. Extraction the image of target from the scattering noise is done by background subtraction and edge detection techniques. As a conclusion, we present a high response laser imaging system to detect and discriminate small size, like-mine underwater targets.

  2. Dependence of mis-alignment sensitivity of ring laser gyro cavity on cavity parameters

    NASA Astrophysics Data System (ADS)

    Sun, Feng; Zhang, Xi; Zhang, Hong-Bo; Yang, Chang-cheng

    2011-02-01

    The ring laser gyroscope (RLG), as a rotation sensor, has been widely used for navigation and guidance on vehicles and missiles. The environment of strong random-vibration and large acceleration may deteriorate the performance of the RLG due to the vibration-induced tilting of the mirrors. In this paper the RLG performance is theoretically analyzed and the parameters such as the beam diameter at the aperture, cavity mirror alignment sensitivities and power loss due to the mirror tilting are calculated. It is concluded that by carefully choosing the parameters, the significant loss in laser power can be avoided.

  3. Method to determine and adjust the alignment of the transmitter and receiver fields of view of a LIDAR system

    DOEpatents

    Schmitt, Randal L.; Henson, Tammy D.; Krumel, Leslie J.; Hargis, Jr., Philip J.

    2006-06-20

    A method to determine the alignment of the transmitter and receiver fields of view of a light detection and ranging (LIDAR) system. This method can be employed to determine the far-field intensity distribution of the transmitter beam, as well as the variations in transmitted laser beam pointing as a function of time, temperature, or other environmental variables that may affect the co-alignment of the LIDAR system components. In order to achieve proper alignment of the transmitter and receiver optical systems when a LIDAR system is being used in the field, this method employs a laser-beam-position-sensing detector as an integral part of the receiver optics of the LIDAR system.

  4. Ultra-fast laser system

    DOEpatents

    Dantus, Marcos; Lozovoy, Vadim V

    2014-01-21

    A laser system is provided which selectively excites Raman active vibrations in molecules. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and remote sensing.

  5. AXAF Alignment Test System Autocollimating Flat Error Correction

    NASA Technical Reports Server (NTRS)

    Lewis, Timothy S.

    1995-01-01

    The alignment test system for the advanced x ray astrophysics facility (AXAF) high-resolution mirror assembly (HRMA) determines the misalignment of the HRMA by measuring the displacement of a beam of light reflected by the HRMA mirrors and an autocollimating flat (ACF). This report shows how to calibrate the system to compensate for errors introduced by the ACF, using measurements taken with the ACF in different positions. It also shows what information can be obtained from alignment test data regarding errors in the shapes of the HRMA mirrors. Simulated results based on measured ACF surface data are presented.

  6. Ruggedized microchannel-cooled laser diode array with self-aligned microlens

    DOEpatents

    Freitas, Barry L.; Skidmore, Jay A.

    2003-11-11

    A microchannel-cooled, optically corrected, laser diode array is fabricated by mounting laser diode bars onto Si surfaces. This approach allows for the highest thermal impedance, in a ruggedized, low-cost assembly that includes passive microlens attachment without the need for lens frames. The microlensed laser diode array is usable in all solid-state laser systems that require efficient, directional, narrow bandwidth, high optical power density pump sources.

  7. Coherent laser vision system

    SciTech Connect

    Sebastion, R.L.

    1995-10-01

    The Coherent Laser Vision System (CLVS) is being developed to provide precision real-time 3D world views to support site characterization and robotic operations and during facilities Decontamination and Decommissioning. Autonomous or semiautonomous robotic operations requires an accurate, up-to-date 3D world view. Existing technologies for real-time 3D imaging, such as AM laser radar, have limited accuracy at significant ranges and have variability in range estimates caused by lighting or surface shading. Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no-moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic to coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  8. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: LASER POWER MEASUREMENTS

    EPA Science Inventory

    Laser power abstract
    The reliability of the confocal laser-scanning microscope (CLSM) to obtain intensity measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. The laser power test appears to be one ...

  9. Alignment Systems For Subassemblies Of Overmolded Optoeletronic Modules

    DOEpatents

    Chan, Benson; Fortier, Paul F.; Guindon, Francois M.; Johnson, Glen W.; Letourneau, Martial A.; Sherman, John H.; Tetreault, Real

    2003-04-15

    Alignment systems for optoelectronic modules with overmolded chip carriers include drilled or milled substrate corners for engaging dowel pins to precisely align the substrate in a mold for molding an overmold frame on the substrate. The overmold frame includes slot and trilobe holes for receiving retainer posts to precisely align a retainer assembly on the overmold frame. Cooperating standoff pads on the overmold frame and on the retainer assembly stabilize the assembly of these components and provide a precise gap for receiving an adhesive to permanently attach these two components. The retainer assembly carries optoelectronic components that include a flexible circuit, and a distal end portion of this flexible circuit and walls of a receiving cavity in the overmold frame have cooperating features for precisely aligning distal electrical leads of the flexible circuit with an array of electrical pads on the substrate. A permanent shroud on a proximate end portion of the flexible circuit protects and helps align proximate electrical leads with electrical pads on optic dies and their carriers.

  10. The rapid growth of vertically aligned carbon nanotubes using laser heating.

    PubMed

    Park, J B; Jeong, S H; Jeong, M S; Lim, S C; Lee, I H; Lee, Y H

    2009-05-01

    Growth of densely packed vertically aligned carbon nanotubes (VA-CNTs) using laser-induced chemical vapor deposition with visible laser (lambda = 532 nm) irradiation at room temperature is reported. Using a multiple-catalyst layer (Fe/Al/Cr) on quartz as the substrate and an acetylene-hydrogen mixture as the precursor gas, VA-CNT pillars with 60 microm height and 4 microm diameter were grown at a high rate of around 1 microm s(-1) with good reproducibility. It is demonstrated that the fabrication of uniform pillar arrays of VA-CNTs can be achieved with a single irradiation for each pillar using LCVD with no annealing or preprocessing of the substrate. Here, laser fast heating is considered the primary mechanism facilitating the growth of VA-CNT pillars. Field emission characteristics of an array of VA-CNT pillars were then examined to investigate their potential application in vacuum electronic devices.

  11. Alignment of Two Grading Systems: A Case Study

    ERIC Educational Resources Information Center

    Hohner, Margaret; Tsigaris, Panagiotis

    2010-01-01

    For the past number of years, a Canadian university has been offering its business degree program in universities located in Tianjin and Shanghai, China. This paper examines the alignment of the two grading systems and its implications on the grade distribution of graduates from the programs. An attempt is made to find an exchange rate of the two…

  12. Study of a module alignment measuring system for UARS

    NASA Technical Reports Server (NTRS)

    1982-01-01

    An alignment measurement system (AMS) which precisely determines the boresights pointing directions of the Upper Atmosphere Research Satellite (UARS) instruments relative to the UARS attitude control system (ACS) was studied. The technology used in on the MAGSAT mission was considered. The AMS optical, mechanical, thermal and electrical system properties were defined. The AMS is constrained to interface with the UARS instrument module and spacecraft layout.

  13. Laser-Induced Alignment and Orientation of Quantum-State Large Molecules

    NASA Astrophysics Data System (ADS)

    Filsinger, Frank; Küpper, Jochen; Meijer, Gerard; Holmegaard, Lotte; Nielsen, Jens H.; Nevo, Iftach; Hansen, Jonas L.; Stapelfeldt, Henrik

    2009-06-01

    For many experiments in chemistry and physics, i. e., reactive scattering, X-ray or electron diffraction experiments, a high level of control over the spatial orientation of molecules would be very beneficial. It is well known that molecules can be aligned and oriented in space using strong dc electric fields or laser pulses. Here, we demonstrate that the degree of laser-induced alignment and orientation can be considerably improved, if quantum state selected samples are used. A strong inhomogeneous electric field is used in a Stern-Gerlach-type experiment to disperse iodobenzene molecules in a supersonic jet according to their rotational quantum state. Molecules in the lowest rotational quantum states are deflected most and can be used as targets for further experiments. This method is widely applicable to all, small and large, polar molecules and should eventually enable experiments on pure samples of strongly aligned or oriented ground-state molecules offering new prospects in molecular sciences. H. Stapelfeldt and T. Seideman, Rev. Mod. Phys., 75, (2003), 543 L. Holmegaard et al., Phys. Rev. Lett., 102, (2009), 023001

  14. Panoramic alignment system for optical wireless communication systems

    NASA Astrophysics Data System (ADS)

    Shen, Thomas C.; Drost, Robert J.; Rzasa, John; Sadler, Brian M.; Davis, Christopher C.

    2015-03-01

    Free space optical communication may provide a viable adjunct to radio frequency (RF) technology for mobile communications, especially in "RF-denied" settings in which RF-based communication may be prohibited or impractical. These settings may include military tactical environments or settings which suffer from RF jamming or interference. Unlike many RF communication systems, point-to-point optical communications between mobile nodes typically require establishing and maintaining alignment, which requires each node to have awareness of the locations of neighboring nodes. We propose a method to create this situational awareness between nodes using purely optical means. This method uses a camera that is focused on a hyperboloidal mirror, thus providing a 360-degree view of the surrounding environment. The camera and mirror are used to detect light emitted from the beacon transmitters from neighboring nodes, with the location of the beacon image in the sensor plane of the camera yielding elevation and azimuth information of the beacon. The beacon transmitter itself is modulated, allowing it to be distinguished from the environment. In discussing our experimental realization of this system, we assess its performance.

  15. Excimer laser system Profile-500

    NASA Astrophysics Data System (ADS)

    Atejev, V. V.; Bukreyev, V. S.; Vartapetov, Serge K.; Semenov, A. D.; Sugrobov, V. A.; Turin, V. S.; Fedorov, Sergei N.

    1999-07-01

    The description of ophthalmological excimer laser system 'PROFILE-500' for photorefractive and physiotherapeutic keratectomy is presented. Excimer Laser Systems 'PROFILE- 500' are optical system that use ArF excimer lasers to perform photorefractive keratectomy or LASIK; surgical procedures used to correct myopia, hyperopia and astigmatism.

  16. Aligning Goal and Value Models for Information System Design

    NASA Astrophysics Data System (ADS)

    Edirisuriya, Ananda; Zdravkovic, Jelena

    The success of process-aware information systems and web services heavily depends on their ability to work as catalysts for the business values that are being exchanged in a business model. The motivation of a business model can be found in the goals of an enterprise which are made explicit in a goal model. From the IT perspective, goal and business models form part of a chain of models, ending with an information system model. Thereby, analyzing and establishing the alignment of business models with goal models is a starting task on the way to a business-aware information system. This paper discusses the alignment of value-based business models with system-oriented goal models. The result is a set of transformation rules between the two models. A case study from the health sector is used to argument the way we ground and apply our contribution.

  17. Design and alignment of the MIPAS focal plane system

    NASA Astrophysics Data System (ADS)

    Smorenburg, C.; Visser, Huib; Moddemeijer, K.

    1996-08-01

    The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) is selected by ESA for the ENVISAT-mission, scheduled for launch in 1999. The instrument will measure the concentration of atmospheric trace gases in the earth atmosphere in a spectral region from 4.15 - 14.6 micrometers . MIPAS consists of scan mirrors, a telescope, a Michelson Interferometer, an optical reducer and a focal plane assembly. The optical reducer consists of a 2 concave and 1 convex mirror system. The focal plane assembly consists of a configuration of mirrors and dichroics, with which the spectral range is divided in 4 spectral bands. TNO Institute of Applied Physics has designed the optical/mechanical system and after manufacturing of the components has aligned the system with high accuracy. The design and alignment of this system is described.

  18. Active annular-beam laser autocollimator system.

    PubMed

    Yoder, P R; Schlesinger, E R; Chickvary, J L

    1975-08-01

    An autocollimator using an axicon and a beam expander telescope to generate a 12.5-cm. o.d. annular beam of helium-neon laser light with high (25:1) diameter-to-width ratio has been developed. It is used with a two-axis, electromagnetically actuated mirror assembly to acquire automatically and maintain dynamically autocollimation from a nearby but separately mounted annular mirror. The servo system controls beam alignment even though angular vibratory motions of the annular mirror make it appear to tilt relative to the autocollimator as much as 7 mrad at frequencies below 300 Hz. This paper describes the optical system and the alignment sensing and control system.

  19. Centroid Detector Assembly for the AXAF-I Alignment Test System

    NASA Technical Reports Server (NTRS)

    Glenn, Paul

    1995-01-01

    The High Resolution Mirror Assembly (HRMA) of the Advanced X-ray Astrophysics Facility (imaging) (AXAF-I) consists of four nested paraboloids and four nested hyperboloids, all of meter-class size, and all of which are to be assembled and aligned in a special 15 meter tower at Eastman Kodak Company in Rochester, NY. The goals of the alignment are (1) to make the images of the four telescopes coincident; (2) to remove coma from each image individually; and (3) to control and determine the final position of the composite focus. This will be accomplished by the HRMA Aligment Test System (HATS) which is essentially a scanning Hartmann test system. The scanning laser source and the focal plane of the HATS are part of the Centroid Detector Assembly (CDA) which also includes processing electronics and software. In this paper we discuss the design and the measured performance of the CDA.

  20. Evidence for unnatural-parity contributions to electron-impact ionization of laser-aligned atoms

    DOE PAGES

    Armstrong, Gregory S. J.; Colgan, James Patrick; Pindzola, M. S.; Amami, S.; Madison, D. H.; Pursehouse, J.; Nixon, K. L.; Murray, A. J.

    2015-09-11

    Recent measurements have examined the electron-impact ionization of excited-state laser-aligned Mg atoms. In this paper we show that the ionization cross section arising from the geometry where the aligned atom is perpendicular to the scattering plane directly probes the unnatural parity contributions to the ionization amplitude. The contributions from natural parity partial waves cancel exactly in this geometry. Our calculations resolve the discrepancy between the nonzero measured cross sections in this plane and the zero cross section predicted by distorted-wave approaches. Finally, we demonstrate that this is a general feature of ionization from p-state targets by additional studies of ionizationmore » from excited Ca and Na atoms.« less

  1. Evidence for unnatural-parity contributions to electron-impact ionization of laser-aligned atoms

    SciTech Connect

    Armstrong, Gregory S. J.; Colgan, James Patrick; Pindzola, M. S.; Amami, S.; Madison, D. H.; Pursehouse, J.; Nixon, K. L.; Murray, A. J.

    2015-09-11

    Recent measurements have examined the electron-impact ionization of excited-state laser-aligned Mg atoms. In this paper we show that the ionization cross section arising from the geometry where the aligned atom is perpendicular to the scattering plane directly probes the unnatural parity contributions to the ionization amplitude. The contributions from natural parity partial waves cancel exactly in this geometry. Our calculations resolve the discrepancy between the nonzero measured cross sections in this plane and the zero cross section predicted by distorted-wave approaches. Finally, we demonstrate that this is a general feature of ionization from p-state targets by additional studies of ionization from excited Ca and Na atoms.

  2. Evidence for unnatural-parity contributions to electron-impact ionization of laser-aligned atoms

    NASA Astrophysics Data System (ADS)

    Armstrong, G. S. J.; Colgan, J.; Pindzola, M. S.; Amami, S.; Madison, D. H.; Pursehouse, J.; Nixon, K. L.; Murray, A. J.

    2015-09-01

    Recent measurements have examined the electron-impact ionization of excited-state laser-aligned Mg atoms. In this work we show that the ionization cross section arising from the geometry where the aligned atom is perpendicular to the scattering plane directly probes the unnatural parity contributions to the ionization amplitude. The contributions from natural parity partial waves cancel exactly in this geometry. Our calculations resolve the discrepancy between the nonzero measured cross sections in this plane and the zero cross section predicted by distorted-wave approaches. We demonstrate that this is a general feature of ionization from p -state targets by additional studies of ionization from excited Ca and Na atoms.

  3. Alignment of human cardiomyocytes on laser patterned biphasic core/shell nanowire assemblies

    NASA Astrophysics Data System (ADS)

    Kiefer, Karin; Lee, Juseok; Haidar, Ayman; Martinez Miró, Marina; Akkan, Cagri Kaan; Veith, Michael; Cenk Aktas, Oral; Abdul-Khaliq, Hashim

    2014-12-01

    The management of end stage heart failure patients is only possible by heart transplantation or by the implantation of artificial hearts as a bridge for later transplantation. However, these therapeutic strategies are limited by a lack of donor hearts and by the associated complications, such as coagulation and infection, due to the used artificial mechanical circulatory assist devices. Therefore, new strategies for myocardial regenerative approaches are under extensive research to produce contractile myocardial tissue in the future to replace non-contractile myocardial ischemic and scarred tissue. Different approaches, such as cell transplantation, have been studied intensively. Although successful approaches have been observed, there are still limitations to the application. It is envisaged that myocardial tissue engineering can be used to help replace infarcted non-contractile tissue. The developed tissue should later mimic the aligned fibrillar structure of the extracellular matrix and provide important guidance cues for the survival, function and the needed orientation of cardiomyocytes. Nanostructured surfaces have been tested to provide a guided direction that cells can follow. In the present study, the cellular adhesion/alignment of human cardiomyocytes and the biocompatibility have been investigated after cultivation on different laser-patterned nanowires compared with unmodified nanowires. As a result, the nanostructured surfaces possessed good biocompatibility before and after laser modification. The laser-induced scalability of the pattern enabled the growth and orientation of the adhered myocardial tissue. Such approaches may be used to modify the surface of potential scaffolds to develop myocardial contractile tissue in the future.

  4. Laser system preset unit

    DOEpatents

    Goodwin, William L.

    1977-01-01

    An electronic circuit is provided which may be used to preset a digital display unit of a Zeeman-effect layer interferometer system which derives distance measurements by comparing a reference signal to a Doppler signal generated at the output of the interferometer laser head. The circuit presets dimensional offsets in the interferometer digital display by electronically inducing a variation in either the Doppler signal or the reference signal, depending upon the direction of the offset, to achieve the desired display preset.

  5. Detecting fiducials affected by trombone delay in ARC and the main laser alignment at the National Ignition Facility

    NASA Astrophysics Data System (ADS)

    Awwal, Abdul A. S.; Bliss, Erlan S.; Miller Kamm, Victoria; Leach, Richard R.; Roberts, Randy; Rushford, Michael C.; Lowe-Webb, Roger; Wilhelmsen, Karl

    2015-09-01

    Four of the 192 beams of the National Ignition Facility (NIF) are currently being diverted into the Advanced Radiographic Capability (ARC) system to generate a sequence of short (1-50 picoseconds) 1053 nm laser pulses. When focused onto high Z wires in vacuum, these pulses create high energy x-ray pulses capable of penetrating the dense, imploding fusion fuel plasma during ignition scale experiments. The transmitted x-rays imaged with x-ray diagnostics can create movie radiographs that are expected to provide unprecedented insight into the implosion dynamics. The resulting images will serve as a diagnostic for tuning the experimental parameters towards successful fusion reactions. Beam delays introduced into the ARC pulses via independent, free-space optical trombones create the desired x-ray image sequence, or movie. However, these beam delays cause optical distortion of various alignment fiducials viewed by alignment sensors in the NIF and ARC beamlines. This work describes how the position of circular alignment fiducials is estimated in the presence of distortion.

  6. Local growth of aligned carbon nanotubes at surface sites irradiated by pulsed laser

    NASA Astrophysics Data System (ADS)

    Zimmer, K.; Böhme, R.; Rauschenbach, B.

    2008-05-01

    The utilization of the unique properties of nanostructures often requires their arrangement in mesoscopic patterns, e.g., to facilitate the connection to microelectrodes. Such arrangements can be achieved by local growth of nanostructures. The stimulation of the localized growth of carbon nanotubes (CNT) has been achieved by excimer laser irradiation of iron(III)nitride-coated silicon substrates at a wavelength of 248 nm. After the growth using a thermal CVD process, vertical aligned CNT bundles were found within the laser-irradiated areas. Pulsed UV-laser irradiation causes the transformation of the nitride film into nanoparticles at the substrate surface as AFM measurements show. Surface modification by direct writing techniques allows the growth of arbitrary shaped CNT-forest patterns. Despite the optimization of the processing parameters, an unequal growth of CNT has been observed at the regions of pulse overlap at direct writing. The dissimilar particle properties at the overlap regions are the reason for the different CNT heights. These differences in the catalytic particles properties are caused by the lower laser fluence at the mask edges and the interaction of the laser plasma plume with the pristine nitride film.

  7. Experimental study of laser-detected magnetic resonance based on atomic alignment

    SciTech Connect

    Di Domenico, Gianni; Bison, Georg; Groeger, Stephan; Knowles, Paul; Pazgalev, Anatoly S.; Rebetez, Martin; Saudan, Herve; Weis, Antoine

    2006-12-15

    We present an experimental study of the spectra produced by optical-radio-frequency double resonance in which resonant linearly polarized laser light is used in the optical pumping and detection processes. We show that the experimental spectra obtained for cesium are in excellent agreement with a very general theoretical model developed in our group [Weis, Bison, and Pazgalev, Phys. Rev. A 74, 033401 (2006)] and we investigate the limitations of this model. Finally, the results are discussed in view of their use in the study of relaxation processes in aligned alkali-metal vapors.

  8. Optimal Position Estimation for the Automatic Alignment of a High Energy Laser

    SciTech Connect

    Candy, J V; Mcclay, W A; Awwal, A S; Ferguson, S W

    2004-07-20

    The alignment of high energy laser beams for potential fusion experiments demand high precision and accuracy by the underlying positioning algorithms whether it be for actuator control or monitoring the beam line for potential anomalies. This paper discusses the feasibility of employing on-line optimal position estimators in the form of model-based processors to achieve the desired results. Here we discuss the modeling, development, implementation and processing of model-based processors applied to both simulated and actual beam line data.

  9. Application of conical 90-degree reflectors for solving the problem of mirror alignment in terahertz-range lasers

    SciTech Connect

    Radionov, V P; Kiselev, V K

    2014-10-29

    We report a study of the conical mirrors with an apex angle of 90° in the resonator of the gas-discharge HCN laser with the radiation wavelength of 337 μm (0.89 THz). Experimental results have shown that such mirrors do not require precise alignment. This makes it possible to improve the radiation stability, significantly simplify the construction of laser and reduce the complexity of its maintenance. (laser applications and other topics in quantum electronics)

  10. Laser Communication System Design

    NASA Astrophysics Data System (ADS)

    Casey, W. L.; Doughty, G. R.; Houston, , J. G.; Marston, R. K.; O'Pella, L. J.; Vo, L. V.

    1988-11-01

    The Air Force is interested in laser communication systems for a variety of air-to-air applications. Laser data transmission offers significant advantages over RF systems in certain areas including higher data rates with low transmitter power, narrower beam divergence leading to difficulty in interception, narrower field of view coupled with high off-axis energy rejection which makes jamming a very formidable task, and smaller antenna size which creates minimum installation impact on an aircraft. The applications with the greatest near-term potential involve the transfer of data between large aircraft operating in relatively benign dynamic environments normally present at altitudes of about 30,000 feet. Systems performing these strategic data exchange (SDE) functions must operate at ranges of 100 to 200 nautical miles at data rates of 2 to 3 megabits per second and the probability of bit error rates not exceeding 10-6. The paper presents the major communication channel elements of a design for a lasercom system performing SDE roles. The design is established by comparing the advantages of the different approaches. The final design selection is based on the transmitter characteristics required for each system. The characteristics include physical properties, development risk, cost, as well as the flexibility for meeting more stringent system performance specifications without requiring major redesign.

  11. Laser multiplexing system

    DOEpatents

    Johnson, Steve A.; English, Jr., Ronald Edward; White, Ronald K.

    2001-01-01

    A plurality of copper lasers, as radiant power sources, emits a beam of power carrying radiation. A plurality of fiber injection assemblies receives power from the plurality of copper lasers and injects such power into a plurality of fibers for individually transmitting the received power to a plurality of power-receiving devices. The power-transmitting fibers of the system are so arranged that power is delivered therethrough to each of the power-receiving devices such that, even if a few of the radiant power sources and/or fibers fail, the power supply to any of the power receiving devices will not completely drop to zero but will drop by the same proportionate amount.

  12. Cryogenic metrology for the James Webb Space Telescope Integrated Science Instrument Module alignment target fixtures using laser radar through a chamber window

    NASA Astrophysics Data System (ADS)

    Hadjimichael, T.; Kubalak, D.; Slotwinski, A.; Davila, P.; Eegholm, B.; Eichhorn, W.; Hayden, J.; Mentzell, E.; Ohl, R.; Scharfstein, G.; Telfer, R.

    2010-08-01

    The James Webb Space Telescope Integrated Science Instrument Module utilizes two fixtures to align the Optical Telescope Element Simulator (OSIM) to the coordinate systems established on the ISIM and the ISIM Test Platform (ITP). These fixtures contain targets which are visible to the OSIM Alignment Diagnostics Module (ADM). Requirements on these fixtures must be met under ambient and cryogenic conditions. This paper discusses the cryogenic metrology involving Laser Radar measurements through a chamber window that will be used to link photogrammetry target measurements used during ISIM structure cryogenic verification and the ADM targets, including evaluation of distortion introduced from the window.

  13. Tailored Fringed Platforms Produced by Laser Interference for Aligned Neural Cell Growth.

    PubMed

    Peláez, Ramón J; González-Mayorga, Ankor; Gutiérrez, María C; García-Rama, Concepción; Afonso, Carmen N; Serrano, María C

    2016-02-01

    Ordering neural cells is of interest for the development of neural interfaces. The aim of this work is to demonstrate an easy-to-use, versatile, and cost/time effective laser-based approach for producing platforms that promote oriented neural growth. We use laser interferometry to generate fringed channels with topography on partially reduced graphene oxide layers as a proof-of-concept substrate. We study cell adhesion, morphology, viability, and differentiation in cultures of embryonic neural progenitor cells on platforms with a 9.4 μm period. Results evidence that fringed platforms significantly promote neurite alignment (≈50% at 6 d), while preserving viability and neural differentiation.

  14. Imaging an aligned polyatomic molecule with laser-induced electron diffraction

    PubMed Central

    Pullen, Michael G.; Wolter, Benjamin; Le, Anh-Thu; Baudisch, Matthias; Hemmer, Michaël; Senftleben, Arne; Schröter, Claus Dieter; Ullrich, Joachim; Moshammer, Robert; Lin, C. D.; Biegert, Jens

    2015-01-01

    Laser-induced electron diffraction is an evolving tabletop method that aims to image ultrafast structural changes in gas-phase polyatomic molecules with sub-Ångström spatial and femtosecond temporal resolutions. Here we demonstrate the retrieval of multiple bond lengths from a polyatomic molecule by simultaneously measuring the C–C and C–H bond lengths in aligned acetylene. Our approach takes the method beyond the hitherto achieved imaging of simple diatomic molecules and is based on the combination of a 160 kHz mid-infrared few-cycle laser source with full three-dimensional electron–ion coincidence detection. Our technique provides an accessible and robust route towards imaging ultrafast processes in complex gas-phase molecules with atto- to femto-second temporal resolution. PMID:26105804

  15. Automated co-alignment of coherent fiber laser arrays via active phase-locking.

    PubMed

    Goodno, Gregory D; Weiss, S Benjamin

    2012-07-01

    We demonstrate a novel closed-loop approach for high-precision co-alignment of laser beams in an actively phase-locked, coherently combined fiber laser array. The approach ensures interferometric precision by optically transducing beam-to-beam pointing errors into phase errors on a single detector, which are subsequently nulled by duplication of closed-loop phasing controls. Using this approach, beams from five coherent fiber tips were simultaneously phase-locked and position-locked with sub-micron accuracy. Spatial filtering of the sensed light is shown to extend the control range over multiple beam diameters by recovering spatial coherence despite the lack of far-field beam overlap.

  16. String-fluid transition in systems with aligned anisotropic interactions.

    PubMed

    Brandt, P C; Ivlev, A V; Morfill, G E

    2010-06-21

    Systems with aligned anisotropic interactions between particles exhibit numerous phase transitions. A remarkable example of the fluid phase transition occurring in such systems is the formation of particle strings--the so-called "string" or "chain" fluids. We employ an approach based on the Ornstein-Zernike (OZ) equation, which allows us to calculate structural properties of fluids with aligned anisotropic interactions. We show that the string-fluid transition can be associated with the bifurcation of the "isotropic" correlation length into two distinct scales which characterize the longitudinal and transverse order in string fluids and, hence, may be used as a fingerprint of this transition. The comparison of the proposed OZ theory with the Monte Carlo simulations reveals fairly good agreement.

  17. String-fluid transition in systems with aligned anisotropic interactions.

    PubMed

    Brandt, P C; Ivlev, A V; Morfill, G E

    2010-06-21

    Systems with aligned anisotropic interactions between particles exhibit numerous phase transitions. A remarkable example of the fluid phase transition occurring in such systems is the formation of particle strings--the so-called "string" or "chain" fluids. We employ an approach based on the Ornstein-Zernike (OZ) equation, which allows us to calculate structural properties of fluids with aligned anisotropic interactions. We show that the string-fluid transition can be associated with the bifurcation of the "isotropic" correlation length into two distinct scales which characterize the longitudinal and transverse order in string fluids and, hence, may be used as a fingerprint of this transition. The comparison of the proposed OZ theory with the Monte Carlo simulations reveals fairly good agreement. PMID:20572736

  18. Understanding Beam Alignment in a Coherent Lidar System

    NASA Technical Reports Server (NTRS)

    Prasad, Narasimha S.; Roychoudhari, Chandrasekhar

    2015-01-01

    Optical beam alignment in a coherent lidar (or ladar) receiver system plays a critical role in optimizing its performance. Optical alignment in a coherent lidar system dictates the wavefront curvature (phase front) and Poynting vector) matching of the local oscillator beam with the incoming receiver beam on a detector. However, this alignment is often not easy to achieve and is rarely perfect. Furthermore, optical fibers are being increasingly used in coherent lidar system receivers for transporting radiation to achieve architectural elegance. Single mode fibers also require stringent mode matching for efficient light coupling. The detector response characteristics vary with the misalignment of the two pointing vectors. Misalignment can lead to increase in DC current. Also, a lens in front of the detector may exasperate phase front and Poynting vector mismatch. Non-Interaction of Waves, or the NIW property indicates the light beams do not interfere by themselves in the absence of detecting dipoles. In this paper, we will analyze the extent of misalignment on the detector specifications using pointing vectors of mixing beams in light of the NIW property.

  19. Alignment effects in two-photon double ionization of H2 in femtosecond xuv laser pulses

    NASA Astrophysics Data System (ADS)

    Guan, Xiaoxu; Bartschat, Klaus; Schneider, Barry I.

    2011-09-01

    Triple-differential cross sections for two-photon double ionization of the aligned hydrogen molecule at the equilibrium distance are presented for a central photon energy of 30 eV. The temporal response of the laser-driven molecule is investigated by solving the time-dependent Schrödinger equation in full dimensionality using two-center elliptical coordinates and a finite-element discrete-variable-representation approach. The molecular orientation is found to have a strong effect on the emission modes of the two correlated photoelectrons. This molecular effect is most noticeable when the molecular axis and the laser polarization vector are oriented parallel to each other. For intermediate cases between the parallel and perpendicular geometries, the dominant emission modes for two-electron ejection oscillate between those for the two extreme cases. The contributions from different ionization channels are also analyzed in detail. Depending on the emission direction of the reference electron, the interference contributions from the various channels can be constructive or destructive at small alignment angles, while they always contribute constructively to the triple-differential cross sections near the perpendicular geometry.

  20. Design and performance of the alignment system for the CMS muon endcaps

    SciTech Connect

    Hohlmann, Marcus; Baksay, Gyongyi; Browngold, Max; Dehmelt, Klaus; Guragain, Samir; Andreev, Valery; Yang, Xiaofeng; Bellinger, James; Carlsmith, Duncan; Feyzi, Farshid; Loveless, Richard J.; /Florida Inst. Tech. /UCLA /Wisconsin U., Madison /UC, Davis /Fermilab /St. Petersburg, INP /UC, Riverside

    2006-12-01

    The alignment system for the CMS Muon Endcap detector employs several hundred sensors such as optical 1-D CCD sensors illuminated by lasers and analog distance- and tilt-sensors to monitor the positions of one sixth of 468 large Cathode Strip Chambers. The chambers mounted on the endcap yoke disks undergo substantial deformation on the order of centimeters when the 4T field is switched on and off. The Muon Endcap alignment system is required to monitor chamber positions with 75-200 {micro}m accuracy in the R? plane, {approx}400 {micro}m in the radial direction, and {approx}1 mm in the z-direction along the beam axis. The complete alignment hardware for one of the two endcaps has been installed at CERN. A major system test was performed when the 4T solenoid magnet was ramped up to full field for the first time in August 2006. We present the overall system design and first results on disk deformations, which indicate that the measurements agree with expectations.

  1. Alignment in star-debris disc systems seen by Herschel

    NASA Astrophysics Data System (ADS)

    Greaves, J. S.; Kennedy, G. M.; Thureau, N.; Eiroa, C.; Marshall, J. P.; Maldonado, J.; Matthews, B. C.; Olofsson, G.; Barlow, M. J.; Moro-Martín, A.; Sibthorpe, B.; Absil, O.; Ardila, D. R.; Booth, M.; Broekhoven-Fiene, H.; Brown, D. J. A.; Cameron, A. Collier; del Burgo, C.; Di Francesco, J.; Eislöffel, J.; Duchêne, G.; Ertel, S.; Holland, W. S.; Horner, J.; Kalas, P.; Kavelaars, J. J.; Lestrade, J.-F.; Vican, L.; Wilner, D. J.; Wolf, S.; Wyatt, M. C.

    2014-02-01

    Many nearby main-sequence stars have been searched for debris using the far-infrared Herschel satellite, within the DEBRIS, DUNES and Guaranteed-Time Key Projects. We discuss here 11 stars of spectral types A-M where the stellar inclination is known and can be compared to that of the spatially resolved dust belts. The discs are found to be well aligned with the stellar equators, as in the case of the Sun's Kuiper belt, and unlike many close-in planets seen in transit surveys. The ensemble of stars here can be fitted with a star-disc tilt of ≲ 10°. These results suggest that proposed mechanisms for tilting the star or disc in fact operate rarely. A few systems also host imaged planets, whose orbits at tens of au are aligned with the debris discs, contrary to what might be expected in models where external perturbers induce tilts.

  2. 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.

  3. Laser system using ultra-short laser pulses

    DOEpatents

    Dantus, Marcos; Lozovoy, Vadim V.; Comstock, Matthew

    2009-10-27

    A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal.

  4. SERI laser scanner system

    SciTech Connect

    Matson, R.J.; Cannon, T.W.

    1980-10-01

    A Laser Scanner System (LSS) produces a photoresponse map and can be used for the nondestructive detection of nonuniformities in the photoresponse of a semiconductor device. At SERI the photoresponse maps are used to identify solar cell faults including microcracks, metallization breaks, regions of poor contact between metallization and the underlying emitter surface, and variations in emitter sheet resistance. The SERI LSS is patterned after the LSS unit documented in the NBS Special Publication 400-24 A Laser Scanner for Semiconductor Devices by D.E. Sawyer and D.W. Berning. Assuming reader familiarity with the above publication, the modifications introduced by SERI are specified with the intention that the two reports can be used to reproduce the SERI LSS. The optical and electronic systems are reviewed, briefly discussing the significant items of each. The most notable difference between the two systems is the SERI substitution of commercially available state-of-the-art modular electronics for the discreet component circuitry used in the NBS LSS.

  5. Laser system for isotope separation

    NASA Astrophysics Data System (ADS)

    Shirayama, Shimpey; Mikatsura, Takefumi; Ueda, Hiroaki; Konagai, Chikara

    1990-06-01

    Atomic vapor laser isotope separation (AVLIS) is regarded as the most promising method to obtain srightly enriched economical nuclear fuel for a nuclear power plant. However, achieving a high power laser seems to be the bottle neck in its industrialization. In 1985, after successful development of high power lasers, the U.S. announced that AVLIS would be used for future methods of uranium enrichment. In Japan , Laser Atomic Separation Enrichment Research Associates of Japan (LASER-J), a joint Japanese utility companies research organization, was founded in April, 1987, to push a development program for laser uranium enrichment. Based on research results obtained from Japanese National Labs, and Universities , Laser-J is now constructing an AVLIS experimental facility at Tokai-mura. It is planned to have a 1-ton swu capacity per year in 1991. Previous to the experimental facility construction , Toshiba proceeded with the preliminary testing of an isotope separation system, under contract with Laser-J. Since the copper vapor laser (CVL) and the dye laser (DL) form a good combination , which can obtain high power tunable visible lights ,it is suitable to resonate uranium atoms. The laser system was built and was successfully operated in Toshiba for two years. The system consist of three copper vapor lasers , three dye lasers and appropriate o Atomic vapor laser isotope separation (AVLIS) is regarded as the most promising method to obtain srightly enriched economical nuclear fuel for a nuclear power plant. However, achieving a high power laser seems to be the bottle neck in its industrialization. In 1985, after successful development of high power lasers, the U.S. announced that AVLIS would be used for future methods of uranium enrichment. In Japan , Laser Atomic Separation Enrichment Research Associates of Japan (LASER-J) , a joint Japanese utility companies research organization , was founded in April, 1987, to push a development program for laser uranium enrichment

  6. Laser interlock system

    SciTech Connect

    Woodruff, Steven D; Mcintyre, Dustin L

    2015-01-13

    A method and device for providing a laser interlock having a first optical source, a first beam splitter, a second optical source, a detector, an interlock control system, and a means for producing dangerous optical energy. The first beam splitter is optically connected to the first optical source, the first detector and the second optical source. The detector is connected to the interlock control system. The interlock control system is connected to the means for producing dangerous optical energy and configured to terminate its optical energy production upon the detection of optical energy at the detector from the second optical source below a predetermined detector threshold. The second optical source produces an optical energy in response to optical energy from the first optical source. The optical energy from the second optical source has a different wavelength, polarization, modulation or combination thereof from the optical energy of the first optical source.

  7. System and method for 2D workpiece alignment

    SciTech Connect

    Weaver, William T.; Carlson, Charles T.; Smith, Scott A.; Beck, Michael A.; Webb, Aaron P.; Strassner, James D.; Gravell, Lawrence R.; Simmons, Michael C.

    2015-07-14

    A carrier capable of holding one or more workpieces is disclosed. The carrier includes movable projections located along the sides of each cell in the carrier. This carrier, in conjunction with a separate alignment apparatus, aligns each workpiece within its respective cell against several alignment pins, using a multiple step alignment process to guarantee proper positioning of the workpiece in the cell. First, the workpieces are moved toward one side of the cell. Once the workpieces have been aligned against this side, the workpieces are then moved toward an adjacent orthogonal side such that the workpieces are aligned to two sides of the cell. Once aligned, the workpiece is held in place by the projections located along each side of each cell. In addition, the alignment pins are also used to align the associated mask, thereby guaranteeing that the mask is properly aligned to the workpiece.

  8. Real-time Optical Alignment and Diagnostic System (ROADS)

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The ultimate and most frequent usage of ROADS will be the alignment of subassemblies (collector and collimator) prior to their installation in a chamber. The system as designed has inherent associated capabilities well applied to acceptance testing of the No. 4 mirror, prediction of in-chamber performance, generation of a catalog of test results and other data, providing data for the plotting of isointensity lines, and other applications which are discussed. The ROADS system will collect, process, display, analyze, and retain data as required for components, partial subassemblies, complete subassemblies, complete modules, and multimodular arrays.

  9. Autonomous monitoring of control hardware to predict off-normal conditions using NIF automatic Alignment Systems

    SciTech Connect

    Awwal, A; Wilhelmsen, K; Leach, R; Kamm, V M; Burkhart, S; Lowe-Webb, R; Cohen, S

    2011-07-20

    The National Ignition Facility (NIF) is a high power laser system capable of supporting high-energy-density experimentation as a user facility for the next 30 years. In order to maximize the facility availability, preventive maintenance enhancements are being introduced into the system. An example of such an enhancement is a camera-based health monitoring system, integrated into the automated alignment system, which provides an opportunity to monitor trends in measurements such as average beam intensity, size of the beam, and pixel saturation. The monitoring system will generate alerts based on observed trends in measurements to allow scheduled pro-active maintenance before routine off-normal detection stops system operations requiring unscheduled intervention.

  10. Second generation laser manufacturing systems

    NASA Astrophysics Data System (ADS)

    La Rocca, Aldo V.

    1996-03-01

    Laser processing can show its full capacity in laser multiprocessing systems applications in which the laser is not hindered by the constraints imposed when the laser is inserted in conventional systems without reassessing the overall system design. In these cases the laser process performance up to now was kept at very low levels because conventional systems would not need or accept higher ones. Instead now said performance must be brought to the upper limits inasmuch as the lasers will be the pacesetter for the performance of the new systems freed from all the old design bondage. Hence the importance to get the maximum performance from each process singly and from their combinations. Better understanding and control of the fluidynamic effects becomes mandatory because of their paramount role on process energy efficiency and thus process productivity and more important yet quality, repeatability and transferability. At present one of the dedicated laser multiprocessing systems of greatest interest is the laser cut-weld of which several have made appearance on the market. Next to come are the 'augmented' laser multiprocessing obtained by combining the laser with conventional processes in a manner which takes advantages of unexpected synergies permitted by the laser. In this manner, the system is allowed to outperform, in all aspects from productivity to quality, the already much higher performance of dedicated all laser multi- processing system. One of the most important 'augmented' laser multiprocessing is the cut- bend-weld. It should be clear that these flexible multiprocessing machines tend to grow naturally in multistation cells and their aggregation in isles and complete manufacturing centers; i.e., the first viable realizations of computer integrated manufacturing.

  11. Theoretical study of terahertz generation from atoms and aligned molecules driven by two-color laser fields

    NASA Astrophysics Data System (ADS)

    Chen, Wenbo; Huang, Yindong; Meng, Chao; Liu, Jinlei; Zhou, Zhaoyan; Zhang, Dongwen; Yuan, Jianmin; Zhao, Zengxiu

    2015-09-01

    We study the generation of terahertz radiation from atoms and molecules driven by an ultrashort fundamental laser and its second-harmonic field by solving the time-dependent Schrödinger equation (TDSE). The comparisons between one-, two-, and three-dimensional TDSE numerical simulations show that the initial ionized wave packet and its subsequent acceleration in the laser field and rescattering with long-range Coulomb potential play key roles. We also present the dependence of the optimum phase delay and yield of terahertz radiation on the laser intensity, wavelength, duration, and ratio of two-color laser components. Terahertz wave generation from model hydrogen molecules is further investigated by comparing with high harmonic emission. It is found that the terahertz yield follows the alignment dependence of the ionization rate, while the optimal two-color phase delays vary by a small amount when the alignment angle changes from 0 to 90 degrees, which reflects the alignment dependence of attosecond electron dynamics. Finally, we show that terahertz emission might be used to clarify the origin of interference in high harmonic generation from aligned molecules by coincidentally measuring the alignment-dependent THz yields.

  12. MACSIMS : multiple alignment of complete sequences information management system

    PubMed Central

    Thompson, Julie D; Muller, Arnaud; Waterhouse, Andrew; Procter, Jim; Barton, Geoffrey J; Plewniak, Frédéric; Poch, Olivier

    2006-01-01

    Background In the post-genomic era, systems-level studies are being performed that seek to explain complex biological systems by integrating diverse resources from fields such as genomics, proteomics or transcriptomics. New information management systems are now needed for the collection, validation and analysis of the vast amount of heterogeneous data available. Multiple alignments of complete sequences provide an ideal environment for the integration of this information in the context of the protein family. Results MACSIMS is a multiple alignment-based information management program that combines the advantages of both knowledge-based and ab initio sequence analysis methods. Structural and functional information is retrieved automatically from the public databases. In the multiple alignment, homologous regions are identified and the retrieved data is evaluated and propagated from known to unknown sequences with these reliable regions. In a large-scale evaluation, the specificity of the propagated sequence features is estimated to be >99%, i.e. very few false positive predictions are made. MACSIMS is then used to characterise mutations in a test set of 100 proteins that are known to be involved in human genetic diseases. The number of sequence features associated with these proteins was increased by 60%, compared to the features available in the public databases. An XML format output file allows automatic parsing of the MACSIM results, while a graphical display using the JalView program allows manual analysis. Conclusion MACSIMS is a new information management system that incorporates detailed analyses of protein families at the structural, functional and evolutionary levels. MACSIMS thus provides a unique environment that facilitates knowledge extraction and the presentation of the most pertinent information to the biologist. A web server and the source code are available at . PMID:16792820

  13. Self-aligned extended-cavity diode laser stabilized by the Zeeman effect on the cesium D2 line.

    PubMed

    Lecomte, S; Fretel, E; Mileti, G; Thomann, P

    2000-03-20

    An extended-cavity diode laser at 852 nm has been built especially for the purpose of cooling and probing cesium atoms. It is a compact, self-aligned, and continuously tunable laser source having a 100-kHz linewidth and 60-mW output power. The electronic control of the laser frequency by the piezodriven external reflector covers a 4.5-kHz bandwidth, allowing full compensation of acoustic frequency noise without any adverse effect on the laser intensity noise. We locked this laser to Doppler-free resonances on the cesium D(2) line by using the Zeeman modulation technique, resulting in the frequency and the intensity of the laser beam being unmodulated. We also tuned the locked laser frequency over a span of 120 MHz by using the dc Zeeman effect to shift the F = 4-F' = 5 reference transition.

  14. Laser system using regenerative amplifier

    DOEpatents

    Emmett, J.L.

    1980-03-04

    High energy laser system is disclosed using a regenerative amplifier, which relaxes all constraints on laser components other than the intrinsic damage level of matter, so as to enable use of available laser system components. This can be accomplished by use of segmented components, spatial filters, at least one amplifier using solid state or gaseous media, and separated reflector members providing a long round trip time through the regenerative cavity, thereby allowing slower switching and adequate time to clear the spatial filters, etc. The laser system simplifies component requirements and reduces component cost while providing high energy output. 10 figs.

  15. Laser system using regenerative amplifier

    DOEpatents

    Emmett, John L. [Pleasanton, CA

    1980-03-04

    High energy laser system using a regenerative amplifier, which relaxes all constraints on laser components other than the intrinsic damage level of matter, so as to enable use of available laser system components. This can be accomplished by use of segmented components, spatial filters, at least one amplifier using solid state or gaseous media, and separated reflector members providing a long round trip time through the regenerative cavity, thereby allowing slower switching and adequate time to clear the spatial filters, etc. The laser system simplifies component requirements and reduces component cost while providing high energy output.

  16. Method and system for aligning fibers during electrospinning

    NASA Technical Reports Server (NTRS)

    Scott-Carnell, Lisa A. (Inventor); Stephens, Ralph M (Inventor); Holloway, Nancy M. (Inventor); Rhim, Caroline (Inventor); Niklason, Laura (Inventor); Clark, Robert L. (Inventor); Siochi, Emilie J. (Inventor)

    2011-01-01

    A method and system are provided for aligning fibers in an electrospinning process. A jet of a fiberizable material is directed towards an uncharged collector from a dispensing location that is spaced apart from the collector. While the fiberizable material is directed towards the collector, an elliptical electric field is generated via the electrically charged dispenser and an oppositely-charged control location. The field spans between the dispensing location and the control location that is within line-of-sight of the dispensing location, and impinges upon at least a portion of the collector. Various combinations of numbers and geometries of dispensers, collectors, and electrodes can be used.

  17. Development of laser transmission system

    NASA Astrophysics Data System (ADS)

    Song, Jiawu; Zhang, Yulan; Yang, Jiandong; Zhang, Xinming

    1998-08-01

    This paper discusses a light transfer system of therapeutic machine using carbon-dioxide laser. This system is based on imitating human being arm motion principle, consists of optical cardans mainly and can move in three-D space freely. Through it carbon-dioxide laser (which wavelength is 10.6 micrometer) is reflected, focused or diverged and transferred to the different therapeutic part of body to realize the purpose of cutting operation, gasification, cauterization and irradiation. This system includes an indicating system using He-Ne laser, by which carbon-dioxide laser can arrive therapeutic part accurately. This system possesses some advantages e.g. an accurate transfer, large moving range, small power consumption, high power density and easy operation. At present the occupancy in home market of this kind laser transfer system products is over 95%. Some products have been exported to other countries.

  18. Alignment-stabilized interference filter-tuned external-cavity quantum cascade laser.

    PubMed

    Kischkat, Jan; Semtsiv, Mykhaylo P; Elagin, Mikaela; Monastyrskyi, Grygorii; Flores, Yuri; Kurlov, Sergii; Peters, Sven; Masselink, W Ted

    2014-12-01

    A passively alignment-stabilized external cavity quantum cascade laser (EC-QCL) employing a "cat's eye"-type retroreflector and an ultra-narrowband transmissive interference filter for wavelength selection is demonstrated and experimentally investigated. Compared with conventional grating-tuned ECQCLs, the setup is nearly two orders of magnitude more stable against misalignment of the components, and spectral fluctuation is reduced by one order of magnitude, allowing for a simultaneously lightweight and fail-safe construction, suitable for applications outdoors and in space. It also allows for a substantially greater level of miniaturization and cost reduction. These advantages fit in well with the general properties of modern QCLs in the promise to deliver useful and affordable mid-infrared-light sources for a variety of spectroscopic and imaging applications.

  19. Observation of laser-induced field-free permanent planar alignment of molecules

    SciTech Connect

    Hoque, Md. Z.; Lapert, M.; Hertz, E.; Billard, F.; Sugny, D.; Lavorel, B.; Faucher, O.

    2011-07-15

    Permanent planar alignment of gas-phase linear molecules is achieved by a pair of delayed perpendicularly polarized short laser pulses. The experiment is performed in a supersonic jet, ensuring a relatively high number density of molecules with moderately low rotational temperature. The effect is optically probed on a femtosecond time scale by the use of a third short pulse, enabling a time-resolved birefringence detection performed successively in two perpendicular planes of the laboratory frame. The technique allows for an unambiguous estimation of the molecular planar delocalization produced within the polarization plane of the pulse pair after the turn-off of the field. The measurements are supported by numerical simulations which lead to the quantification of the observed effect and provide more physical insights into the phenomenon.

  20. Split-aperture laser pulse compressor design tolerant to alignment and line-density differences.

    PubMed

    Rushford, Michael C; Britten, Jerald A; Barty, Christopher P J; Jitsuno, Takahisa; Kondo, Kiminori; Miyanaga, Noriaki; Tanaka, Kazuo A; Kodama, Ryosuke; Xu, Guang

    2008-08-15

    We introduce a four-pass laser pulse compressor design based on two grating apertures with two gratings per aperture that is tolerant to some alignment errors and, importantly, to grating-to-grating period variations. Each half-beam samples each grating in a diamond-shaped compressor that is symmetric about a central bisecting plane. For any given grating, the two half-beams impinge on opposite sides of its surface normal. It is shown that the two split beams have no pointing difference from paired gratings with different periods. Furthermore, no phase shift between half-beams is incurred as long as the planes containing a grating line and the surface normal for each grating of the pair are parallel. For grating pairs satisfying this condition, gratings surfaces need not be on the same plane, as changes in the gap between the two can compensate to bring the beams back in phase.

  1. Split-aperture laser pulse compressor design tolerant to alignment and line-density differences.

    PubMed

    Rushford, Michael C; Britten, Jerald A; Barty, Christopher P J; Jitsuno, Takahisa; Kondo, Kiminori; Miyanaga, Noriaki; Tanaka, Kazuo A; Kodama, Ryosuke; Xu, Guang

    2008-08-15

    We introduce a four-pass laser pulse compressor design based on two grating apertures with two gratings per aperture that is tolerant to some alignment errors and, importantly, to grating-to-grating period variations. Each half-beam samples each grating in a diamond-shaped compressor that is symmetric about a central bisecting plane. For any given grating, the two half-beams impinge on opposite sides of its surface normal. It is shown that the two split beams have no pointing difference from paired gratings with different periods. Furthermore, no phase shift between half-beams is incurred as long as the planes containing a grating line and the surface normal for each grating of the pair are parallel. For grating pairs satisfying this condition, gratings surfaces need not be on the same plane, as changes in the gap between the two can compensate to bring the beams back in phase. PMID:18709127

  2. Variable emissivity laser thermal control system

    DOEpatents

    Milner, Joseph R.

    1994-01-01

    A laser thermal control system for a metal vapor laser maintains the wall mperature of the laser at a desired level by changing the effective emissivity of the water cooling jacket. This capability increases the overall efficiency of the laser.

  3. Laser power conversion system analysis

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Orbit to orbit and orbit to ground laser power conversion systems and power transfer are discussed. A system overview is presented. Pilot program parameters are considered: SLPS assumptions are listed, a laser SPS overview is presented, specifications are listed, and SLPS coats are considered.

  4. Improved production of Br atoms near zero speed by photodissociating laser aligned Br{sub 2} molecules

    SciTech Connect

    Deng, L. Z. Yin, J. P.

    2014-10-28

    We theoretically investigated the improvement on the production rate of the decelerated bromine (Br) atoms near zero speed by photodissociating laser aligned Br{sub 2} precursors. Adiabatic alignment of Br{sub 2} precursors exposed to long laser pulses with duration on the order of nanoseconds was investigated by solving the time-dependent Schrödinger equation. The dynamical fragmentation of adiabatically aligned Br{sub 2} precursors was simulated and velocity distribution of the Br atoms produced was analyzed. Our study shows that the larger the degree of the precursor alignment, 〈cos{sup 2} θ〉, the higher the production rate of the decelerated Br atoms near zero speed. For Br{sub 2} molecules with an initial rotational temperature of ∼1 K, a 〈cos{sup 2} θ〉 value of ∼0.88 can result in an improvement factor of over ∼20 on the production rate of the decelerated Br atoms near zero speed, requiring a laser intensity of only ∼1 × 10{sup 12} W/cm{sup 2} for alignment.

  5. Ultrafast electron diffraction from laser-aligned molecules in the gas phase

    NASA Astrophysics Data System (ADS)

    Yang, Jie

    Ultrafast electron diffraction has emerged since the end of last century, and has become an increasingly important tool for revealing great details of molecular dynamics. In comparison to spectroscopic techniques, ultrafast electron diffraction directly probes time-resolved structure of target molecules, and therefore can potentially provide "molecular movies" of the reactions being studied. These molecular movies are critical for understanding and ultimately controlling the energy conversion pathways and efficiencies of photochemical processes. In this dissertation, I have focused on ultrafast electron diffraction from gas-phase molecules, and have investigated several long-standing challenges that have been preventing researchers from being able to achieve 3-D molecular movies of photochemical reactions. The first challenge is to resolve the full 3-D structure for molecules in the gas phase. The random orientation of molecules in the gas phase smears out the diffraction signal, which results in only 1-D structural information being accessible. The second challenge lies in temporal resolution. In order to resolve coherent nuclear motions on their natural time scale, a temporal resolution of ˜200 femtosecond or better is required. However, due to experimental limitations the shortest temporal resolution that had been achieved was only a few picoseconds in early 2000, by Zewail group from Caltech. The first challenge is tackled by laser-alignment. In the first half of the dissertation, I approach this method both theoretically and experimentally, and demonstrate that by using a short laser pulse to transiently align target molecules in space, 3-D molecular structure can be reconstructed ab-initio from diffraction patterns. The second half of the dissertation presents two experiments, both of which are important steps toward imaging coherent nuclear motions in real time during photochemical reactions. The first experiment simultaneously resolves molecular alignment

  6. A GaAs-based self-aligned stripe distributed feedback laser

    NASA Astrophysics Data System (ADS)

    Lei, H.; Stevens, B. J.; Fry, P. W.; Babazadeh, N.; Ternent, G.; Childs, D. T.; Groom, K. M.

    2016-08-01

    We demonstrate operation of a GaAs-based self-aligned stripe (SAS) distributed feedback (DFB) laser. In this structure, a first order GaInP/GaAs index-coupled DFB grating is built within the p-doped AlGaAs layer between the active region and the n-doped GaInP opto-electronic confinement layer of a SAS laser structure. In this process no Al-containing layers are exposed to atmosphere prior to overgrowth. The use of AlGaAs cladding affords the luxury of full flexibility in upper cladding design, which proved necessary due to limitations imposed by the grating infill and overgrowth with the GaInP current block layer. Resultant devices exhibit single-mode lasing with high side-mode-suppression of >40 dB over the temperature range 20 °C-70 °C. The experimentally determined optical profile and grating confinement correlate well with those simulated using Fimmwave.

  7. A GaAs-based self-aligned stripe distributed feedback laser

    NASA Astrophysics Data System (ADS)

    Lei, H.; Stevens, B. J.; Fry, P. W.; Babazadeh, N.; Ternent, G.; Childs, D. T.; Groom, K. M.

    2016-08-01

    We demonstrate operation of a GaAs-based self-aligned stripe (SAS) distributed feedback (DFB) laser. In this structure, a first order GaInP/GaAs index-coupled DFB grating is built within the p-doped AlGaAs layer between the active region and the n-doped GaInP opto-electronic confinement layer of a SAS laser structure. In this process no Al-containing layers are exposed to atmosphere prior to overgrowth. The use of AlGaAs cladding affords the luxury of full flexibility in upper cladding design, which proved necessary due to limitations imposed by the grating infill and overgrowth with the GaInP current block layer. Resultant devices exhibit single-mode lasing with high side-mode-suppression of >40 dB over the temperature range 20 °C–70 °C. The experimentally determined optical profile and grating confinement correlate well with those simulated using Fimmwave.

  8. 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.

  9. Reflex ring laser amplifier system

    DOEpatents

    Summers, Mark A.

    1985-01-01

    A laser pulse is injected into an unstable ring resonator-amplifier structure. Inside this resonator the laser pulse is amplified, spatially filtered and magnified. The laser pulse is recirculated in the resonator, being amplified, filtered and magnified on each pass. The magnification is chosen so that the beam passes through the amplifier in concentric non-overlapping regions similar to a single pass MOPA. After a number of passes around the ring resonator the laser pulse is spatially large enough to exit the ring resonator system by passing around an output mirror.

  10. Multiple pass laser amplifier system

    DOEpatents

    Brueckner, Keith A.; Jorna, Siebe; Moncur, N. Kent

    1977-01-01

    A laser amplification method for increasing the energy extraction efficiency from laser amplifiers while reducing the energy flux that passes through a flux limited system which includes apparatus for decomposing a linearly polarized light beam into multiple components, passing the components through an amplifier in delayed time sequence and recombining the amplified components into an in phase linearly polarized beam.

  11. Heat transfer in vertically aligned phase change energy storage systems

    SciTech Connect

    El-Dessouky, H.T.; Bouhamra, W.S.; Ettouney, H.M.; Akbar, M.

    1999-05-01

    Convection effects on heat transfer are analyzed in low temperature and vertically aligned phase change energy storage systems. This is performed by detailed temperature measurements in the phase change material (PCM) in eighteen locations forming a grid of six radial and three axial positions. The system constitutes a double pipe configuration, where commercial grade paraffin wax is stored in the annular space between the two pipes and water flows inside the inner pipe. Vertical alignment of the system allowed for reverse of the flow direction of the heat transfer fluid (HTF), which is water. Therefore, the PCM is heated from the bottom for HTF flow from bottom to top and from the top as the HTF flow direction is reversed. For the former case, natural convection affects the melting process. Collected data are used to study variations in the transient temperature distribution at axial and radial positions as well as for the two-dimensional temperature field. The data are used to calculate the PCM heat transfer coefficient and to develop correlations for the melting Fourier number. Results indicate that the PCM heat transfer coefficient is higher for the case of PCM heating from bottom to top. Nusselt number correlations are developed as a function of Rayleigh, Stefan, and Fourier numbers for the HTF flow from bottom to top and as a function of Stefan and Fourier numbers for HTF flow from top to bottom. The enhancement ratio for heat transfer caused by natural convection increases and then levels off as the inlet temperature of the HTF is increased.

  12. Alignment reference device

    DOEpatents

    Patton, Gail Y.; Torgerson, Darrel D.

    1987-01-01

    An alignment reference device provides a collimated laser beam that minimizes angular deviations therein. A laser beam source outputs the beam into a single mode optical fiber. The output end of the optical fiber acts as a source of radiant energy and is positioned at the focal point of a lens system where the focal point is positioned within the lens. The output beam reflects off a mirror back to the lens that produces a collimated beam.

  13. Laser Transmitter Design for the Geoscience Laser Altimeter System

    NASA Technical Reports Server (NTRS)

    Afzal, R. S.; Yu, A. W.; Mamakos, W.; Lukemire, A.; Dallas, J. L.; Schroeder, B.; Green, J. W.

    1998-01-01

    NASA is embarking on a new era of laser remote sensing instruments from space. This paper focuses specifically on the laser technology involved in one of the present NASA missions. The Geoscience Laser Altimeter System (GLAS) scheduled to launch in 2001 is a laser altimeter and lidar for the Earth Observing System's (EOS) ICESat mission. The laser transmitter for this space-based remote sensing instrument is discussed in the context of the mission requirements.

  14. Specific features of propagation of femtosecond laser pulses through a molecular gaseous medium under conditions of efficient alignment of molecules

    SciTech Connect

    Gulyaev, A V; Tikhonova, O V

    2013-07-31

    The propagation of femtosecond laser pulses in a molecular gaseous medium is studied with the rotational dynamics of molecules under the action of these pulses taken into account. Based on the simultaneous numerical solution of the wave equation describing the laser pulse evolution and the Schroedinger equation that determines the quantum state evolution of the medium molecules, the rotational dynamics of molecules in the laser field and the laser pulse evolution are analysed with their mutual influence taken into account. Efficient dynamic alignment of molecules along the direction of laser radiation polarisation is observed, which causes variation in the spatiotemporal pulse profile, as well as significant broadening and deformation of its spectrum in the course of propagation through the medium. The physical mechanisms of the observed phenomena are analysed by using the approximate analytical solution of the problem, derived for the case of preliminary excitation of the medium by a pump pulse (the pump-probe scheme). (nonlinear optical phenomena)

  15. Alignment dependence of photoelectron momentum distributions of atomic and molecular targets probed by few-cycle circularly polarized laser pulses

    NASA Astrophysics Data System (ADS)

    Abu-samha, M.; Madsen, Lars Bojer

    2016-08-01

    We present theoretical photoelectron momentum distributions (PMDs) for ionization from Ar(3 p ) and H2+ (σg) orbitals by few-cycle, high-intensity, near-infrared laser fields circularly polarized in the x y plane. The three-dimensional time-dependent Schrödinger equation is solved numerically within the single-active-electron approximation for Ar and within the fixed nuclei approximation for H2+ . The PMDs are investigated for alignment of the probed target orbitals relative to the polarization plane of the laser field. In the atomic case, the PMDs in the polarization plane for aligned 3 p Ar orbitals are, up to an overall scaling factor, insensitive to alignment of the probed orbital, while the lateral PMDs show a signature of the orbital node when that node is sufficiently close to the polarization plane. For the molecular case of H2+ (σg), our results show a significant impact of alignment on the PMDs due to the anisotropic molecular potential and the alignment-dependent coupling between the ground state and excited states.

  16. Precise alignment of the collection fiber assisted by real-time plasma imaging in laser-induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Motto-Ros, V.; Negre, E.; Pelascini, F.; Panczer, G.; Yu, J.

    2014-02-01

    Improving the repeatability and the reproducibility of measurement with laser-induced breakdown spectroscopy (LIBS) is one of the actual challenging issues faced by the technique to fit the requirements of precise and accurate quantitative analysis. Among the numerous factors influencing the measurement stability in short and long terms, there are shot-to-shot and day-to-day fluctuations of the morphology of the plasma. Such fluctuations are due to the high sensitivity of laser-induced plasma to experimental conditions including properties of the sample, the laser parameters as well as properties of the ambient gas. In this paper, we demonstrate that precise alignment of the optical fiber for the collection of the plasma emission with respect to the actual morphology of the plasma assisted by real-time imaging, greatly improves the stability of LIBS measurements in short as well as in long terms. The used setup is based on a plasma imaging arrangement using a CCD camera and a real-time image processing. The obtained plasma image is displayed in a 2-dimensional frame where the position of the optical fiber is beforehand calibrated. In addition, the setup provides direct sample surface monitoring, which allows a precise control of the distance between the focusing lens and the sample surface. Test runs with a set of 8 reference samples show very high determination coefficient for calibration curves (R2 = 0.9999), and a long term repeatability and reproducibility of 4.6% (relative standard deviation) over a period of 3 months without any signal normalization. The capacity of the system to automatically correct the sample surface position for a tilted or non-regular sample surface during a surface mapping measurement is also demonstrated.

  17. Near Field Intensity Trends of Main Laser Alignment Images in the National Ignition Facility (NIF)

    SciTech Connect

    Leach, R R; Beltsar, I; Burkhart, S; Lowe-Webb, R; Kamm, V M; Salmon, T; Wilhelmsen, K

    2015-01-22

    The National Ignition Facility (NIF) utilizes 192 high-energy laser beams focused with enough power and precision on a hydrogen-filled spherical, cryogenic target to potentially initiate a fusion reaction. NIF has been operational for six years; during that time, thousands of successful laser firings or shots have been executed. Critical instrument measurements and camera images are carefully recorded for each shot. The result is a massive and complex database or ‘big data’ archive that can be used to investigate the state of the laser system at any point in its history or to locate and track trends in the laser operation over time. In this study, the optical light throughput for more than 1600 NIF shots for each of the 192 main laser beams and 48 quads was measured over a three year period from January 2009 to October 2012. The purpose was to verify that the variation in the transmission of light through the optics over time performed within design expectations during this time period. Differences between average or integrated intensity from images recorded by the input sensor package (ISP) and by the output sensor package (OSP) in the NIF beam-line were examined. A metric is described for quantifying changes in the integrated intensity measurements and was used to view potential trends. Results are presented for the NIF input and output sensor package trends and changes over the three year time-frame.

  18. Swept Frequency Laser Metrology System

    NASA Technical Reports Server (NTRS)

    Zhao, Feng (Inventor)

    2010-01-01

    A swept frequency laser ranging system having sub-micron accuracy that employs multiple common-path heterodyne interferometers, one coupled to a calibrated delay-line for use as an absolute reference for the ranging system. An exemplary embodiment uses two laser heterodyne interferometers to create two laser beams at two different frequencies to measure distance and motions of target(s). Heterodyne fringes generated from reflections off a reference fiducial X(sub R) and measurement (or target) fiducial X(sub M) are reflected back and are then detected by photodiodes. The measured phase changes Delta phi(sub R) and Delta phi (sub m) resulting from the laser frequency swept gives target position. The reference delay-line is the only absolute reference needed in the metrology system and this provides an ultra-stable reference and simple/economical system.

  19. Design of practical alignment device in KSTAR Thomson diagnostic

    NASA Astrophysics Data System (ADS)

    Lee, J. H.; Lee, S. H.; Yamada, I.

    2016-11-01

    The precise alignment of the laser path and collection optics in Thomson scattering measurements is essential for accurately determining electron temperature and density in tokamak experiments. For the last five years, during the development stage, the KSTAR tokamak's Thomson diagnostic system has had alignment fibers installed in its optical collection modules, but these lacked a proper alignment detection system. In order to address these difficulties, an alignment verifying detection device between lasers and an object field of collection optics is developed. The alignment detection device utilizes two types of filters: a narrow laser band wavelength for laser, and a broad wavelength filter for Thomson scattering signal. Four such alignment detection devices have been successfully developed for the KSTAR Thomson scattering system in this year, and these will be tested in KSTAR experiments in 2016. In this paper, we present the newly developed alignment detection device for KSTAR's Thomson scattering diagnostics.

  20. System for maintaining the alignment of mandrels in filament winding operations

    DOEpatents

    Robinson, Samuel C.; Dodge, William G.; Pollard, Roy E.

    1984-01-01

    The present invention is directed to a system for sensing and correcting the alignment of a mandrel being wound with filamentary material with respect to the filamentary material winding mechanism. A positioned reference pin attached to the mandrel is positioned in a beam of collimated light emanating from a laser so as to bisect the light beam and create a shadow therebetween. A pair of photocells are positioned to receive the bisected light beam with the shadow uniformly located between the photocells when the pin is in a selected position. The mandrel is supported in the selected position for the winding of a filamentary material by a position adjustable roller mechanism which is coupled by a screw drive to a reversible motor. Changes in the pin position such as caused by winding growth are sensed by the photocells to provide the displacement of the roller mechanism in the direction necessary to return the mandrel to the selected position.

  1. System for maintaining the alignment of mandrels in filament winding operations

    DOEpatents

    Robinson, S.C.; Dodge, W.G.; Pollard, R.E.

    1983-10-12

    The present invention is directed to a system for sensing and correcting the alignment of a mandrel being wound with filamentary material with respect to the filamentary material winding mechanism. A positioned reference pin attached to the mandrel is positioned in a beam of collimated light emanating from a laser so as to bisect the light beam and create a shadow therebetween. A pair of photocells are positioned to receive the bisected light beam with the shadow uniformly located between the photocells when the pin is in a selected position. The mandrel is supported in the selected position for the winding of a filamentary material by a position adjustable roller mechanism which is coupled by a screw drive to a reversible motor. Changes in the pin position such as caused by winding growth are sensed by the photocells to provide the displacement of the roller mechanism in the direction necessary to return the mandrel to the selected position.

  2. Lessons Learned from the Advanced Topographic Laser Altimeter System

    NASA Technical Reports Server (NTRS)

    Garrison, Matt; Patel, Deepak; Bradshaw, Heather; Robinson, Frank; Neuberger, Dave

    2016-01-01

    The ICESat-2 Advanced Topographic Laser Altimeter System (ATLAS) instrument is an upcoming Earth Science mission focusing on the effects of climate change. The flight instrument passed all environmental testing at GSFC (Goddard Space Flight Center) and is now ready to be shipped to the spacecraft vendor for integration and testing. This presentation walks through the lessons learned from design, hardware, analysis and testing perspective. ATLAS lessons learned include general thermal design, analysis, hardware, and testing issues as well as lessons specific to laser systems, two-phase thermal control, and optical assemblies with precision alignment requirements.

  3. Guidance system for laser targets

    DOEpatents

    Porter, Gary D.; Bogdanoff, Anatoly

    1978-01-01

    A system for guiding charged laser targets to a predetermined focal spot of a laser along generally arbitrary, and especially horizontal, directions which comprises a series of electrostatic sensors which provide inputs to a computer for real time calculation of position, velocity, and direction of the target along an initial injection trajectory, and a set of electrostatic deflection means, energized according to a calculated output of said computer, to change the target trajectory to intercept the focal spot of the laser which is triggered so as to illuminate the target of the focal spot.

  4. Stimulated Brillouin scattering mirror system, high power laser and laser peening method and system using same

    DOEpatents

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2007-04-24

    A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.

  5. Laser photography system: hardware configuration

    NASA Astrophysics Data System (ADS)

    Piszczek, Marek; Rutyna, Krzysztof; Kowalski, Marcin; Zyczkowski, Marek

    2012-06-01

    Solution presented in this article is a system using image acquisition time gating method. The time-spatial framing method developed by authors was used to build Laser Photography System (LPS). An active vision system for open space monitoring and terrorist threats detection is being built as an effect of recent work lead in the Institute of Optoelectronics, MUT. The device is destined to prevent and recognize possible terrorist threats in important land and marine areas. The aim of this article is to discuss the properties and hardware configuration of the Laser Photography System.

  6. Shilnikov instabilities in laser systems

    SciTech Connect

    Swetits, J.J.; Buoncristiani, A.M.

    1988-11-15

    Experiments on a CO/sub 2/ laser with feedback (F. T. Arecchi, R. Meucci, and W. Gadomski, Phys. Rev. Lett. 58, 2205 (1987)) displayed an extraordinary set of instabilities, identified as Shilnikov chaos. We have investigated the stability structure of a theoretical model developed to describe this laser system and carried out an extensive numerical search for the Shilnikov instability. No computational evidence to support the claim of a Shilnikov instability for model parameters corresponding to the experimental region can be found.

  7. Laser Pyro System Standardization and Man Rating

    NASA Technical Reports Server (NTRS)

    Brown, Christopher W.

    2004-01-01

    This viewgraph presentation reviews an X-38 laser pyro system standardization system designed for a new manned rated program. The plans to approve this laser initiation system and preliminary ideas for this system are also provided.

  8. Alignment of an aspheric mirror subsystem for an advanced infrared catadioptric system

    NASA Astrophysics Data System (ADS)

    Tingstad, James S.

    1991-12-01

    With many optical systems the method that is used to align the optical system needs to be an integral portion of the system design and not an afterthought. Once all the pieces are in fabrication it may be too late to implement a cost-effective alignment procedure for both prototype and production designs. This is especially true with catadioptric systems where the mirror alignment tends to be very critical as far as system performance is concerned. This paper describes the design and use of an aspheric null mirror for the alignment of a two mirror subsystem to a lens cell. The optical system to be aligned was a six-in. EFL, F/2 system working in the 3-5 micrometers bandpass. It consisted of two aspheric mirrors, one aspheric lens, and two spherical lenses.

  9. Underwater laser imaging system (UWLIS)

    SciTech Connect

    DeLong, M.

    1994-11-15

    Practical limitations with underwater imaging systems area reached when the noise in the back scattered radiation generated in the water between the imaging system and the target obscures the spatial contrast and resolution necessary for target discovery and identification. The advent of high power lasers operating in the blue-green portion of the visible spectrum (oceanic transmission window) has led to improved experimental illumination systems for underwater imaging. Range-gated and synchronously scanned devices take advantage of the unique temporal and spatial coherence properties of laser radiation, respectively, to overcome the deleterious effects of common volume back scatter.

  10. A simple laser system for atom interferometry

    NASA Astrophysics Data System (ADS)

    Merlet, S.; Volodimer, L.; Lours, M.; Pereira Dos Santos, F.

    2014-07-01

    We present here a simple laser system for a laser-cooled atom interferometer, where all functions (laser cooling, interferometry and detection) are realized using only two extended cavity laser diodes, amplified by a common tapered amplifier. One laser is locked by frequency modulation transfer spectroscopy, the other being phase locked with an offset frequency determined by an field-programmable gate array-controlled direct digital synthesizer, which allows for efficient and versatile tuning of the laser frequency. Raman lasers are obtained with a double pass acoustooptic modulator. We demonstrate a gravimeter using this laser system, with performances close to the state of the art.

  11. XI UV Laser Trigger System

    SciTech Connect

    Brickeen, B.K.; Morelli, G.L.; Paiva, R.A.; Powell, C.A.; Sundvold, P.D.

    1999-01-26

    The X1 accelerator project at Sandia National Laboratory/New Mexico utilizes SF6 insulated, multi-stage, UV laser triggered gas switches. A 265 nm UV laser system was designed and built to generate eight simultaneous output pulses of 10 mJ each with a 13 nsec pulse width. A 1061 nm solid-state Nd:Cr:GSGG laser was frequency quadrupled using a two-stage doubling process. The 1061 nm fundamental laser energy was frequency doubled with a KTP crystal to 530 nm, achieving 65% conversion efficiency. The 530 nm output was frequency doubled with KD*P crystal to 265 nm, achieving conversion efficiency of 31%. The 265 nm beam pulse was split into eight parallel channels with a system of partially reflecting mirrors. Low timing jitter and stable energy output were achieved. The entire optical system was packaged into a rugged, o-ring sealed, aluminum structure 10''x19''x2.75''. The size of the electronics was 12''x8''x8''. Subsequent accelerator system requirements dictated a redesign of the triggering system for an output beam with less angular divergence. An unstable, crossed porro prism resonator was designed and incorporated into the system. The beam divergence of the redesigned system was successfully decreased to 0.97 mrad in the UV. The resulting frequency doubling efficiencies were 55% to 530 nm and 25% to 265 nm. The optical output remained at 10 mJ in each channel with an 11 nsec pulse width.

  12. Novel liquid-crystal alignment method using polarized laser light (Invited Paper)

    NASA Astrophysics Data System (ADS)

    Sun, Shao-Tang; Gibbons, Wayne M.; Shannon, Paul J.

    1992-10-01

    The control of liquid crystal alignment is of critical importance to the electro-optic performance of a liquid crystal display. Recently a new alignment method was discovered. Instead of the conventional buffing technique, polarized light is employed to treat the polymer alignment layer on the substrate of the display cell for the control of liquid crystal orientation. This non-contact method of aligning liquid crystals offers unique possibilities for display cell repair or reconfiguration after cell assembly. In addition, novel liquid crystal phase devices can be realized for use in optical processing.

  13. Control of field-free molecular alignment by phase-shaped laser pulses

    SciTech Connect

    Renard, M.; Hertz, E.; Guerin, S.; Jauslin, H.R.; Lavorel, B.; Faucher, O.

    2005-08-15

    We report an experimental study of the control of molecular alignment of N{sub 2} by use of spectrally modulated pulses at an intensity regime below the intrinsic saturation of the alignment. By manipulating the relative timing of the alignment revival pattern arising from the even subset of the thermal ensemble as compared to the odd subset, we demonstrate that the angular distribution of the aligned molecule can be converted into planar delocalization at specific times. We also show that the angular focusing of the molecular axis can be switched off by applying a specific bipulse.

  14. Heterodyne laser instantaneous frequency measurement system

    DOEpatents

    Wyeth, Richard W.; Johnson, Michael A.; Globig, Michael A.

    1989-01-01

    A heterodyne laser instantaneous frequency measurement system is disclosed. The system utilizes heterodyning of a pulsed laser beam with a continuous wave laser beam to form a beat signal. The beat signal is processed by a controller or computer which determines both the average frequency of the laser pulse and any changes or chirp of th frequency during the pulse.

  15. Heterodyne laser instantaneous frequency measurement system

    DOEpatents

    Wyeth, Richard W.; Johnson, Michael A.; Globig, Michael A.

    1990-01-01

    A heterodyne laser instantaneous frequency measurement system is disclosed. The system utilizes heterodyning of a pulsed laser beam with a continuous wave laser beam to form a beat signal. The beat signal is processed by a controller or computer which determines both the average frequency of the laser pulse and any changes or chirp of the frequency during the pulse.

  16. Alignment of chirped-pulse compressor

    SciTech Connect

    Yakovlev, I V

    2012-11-30

    An original method of alignment of grating compressors for ultrahigh-power CPA laser systems is proposed. The use of this method for adjustment of the grating compressor of a PEARL subpetawatt laser complex made it possible to align the diffraction gratings with a second accuracy in all three angular degrees of freedom, including alignment of the grooves, and to adjust the angles of beam incidence on the grating with a high accuracy. A simple method for measuring the difference in the groove densities of gratings with accuracy better than 0.005 lines mm{sup -1} is proposed and tested. (control of laser radiation parameters)

  17. Stretchers and compressors for ultra-high power laser systems

    SciTech Connect

    Yakovlev, I V

    2014-05-30

    This review is concerned with pulse stretchers and compressors as key components of ultra-high power laser facilities that take advantage of chirped-pulse amplification. The potentialities, characteristics, configurations and methods for the matching and alignment of these devices are examined, with particular attention to the history of the optics of ultra-short, ultra-intense pulses before and after 1985, when the chirped-pulse amplification method was proposed, which drastically changed the view of the feasibility of creating ultra-high power laser sources. The review is intended primarily for young scientists and experts who begin to address the amplification and compression of chirped pulses, experts in laser optics and all who are interested in scientific achievements in the field of ultra-high power laser systems. (review)

  18. ARGOS laser system mechanical design

    NASA Astrophysics Data System (ADS)

    Deysenroth, M.; Honsberg, M.; Gemperlein, H.; Ziegleder, J.; Raab, W.; Rabien, S.; Barl, L.; Gässler, W.; Borelli, J. L.

    2014-07-01

    ARGOS, a multi-star adaptive optics system is designed for the wide-field imager and multi-object spectrograph LUCI on the LBT (Large Binocular Telescope). Based on Rayleigh scattering the laser constellation images 3 artificial stars (at 532 nm) per each of the 2 eyes of the LBT, focused at a height of 12 km (Ground Layer Adaptive Optics). The stars are nominally positioned on a circle 2' in radius, but each star can be moved by up to 0.5' in any direction. For all of these needs are following main subsystems necessary: 1. A laser system with its 3 Lasers (Nd:YAG ~18W each) for delivering strong collimated light as for LGS indispensable. 2. The Launch system to project 3 beams per main mirror as a 40 cm telescope to the sky. 3. The Wave Front Sensor with a dichroic mirror. 4. The dichroic mirror unit to grab and interpret the data. 5. A Calibration Unit to adjust the system independently also during day time. 6. Racks + platforms for the WFS units. 7. Platforms and ladders for a secure access. This paper should mainly demonstrate how the ARGOS Laser System is configured and designed to support all other systems.

  19. Target alignment in the National Ignition Facility

    SciTech Connect

    Vann, C.S.; Bliss, E.S.; Murray, J.E.

    1994-06-06

    Accurate placement of hundreds of focused laser beams on target is necessary to achieve success in the National Ignition Facility (NIF). The current system requirement is {le}7 {mu}rad error in output pointing and {le}1 mm error in focusing. To accommodate several system shots per day, a target alignment system must be able to align the target to chamber center, inject an alignment beam to represent each shot beam, and point and focus the alignment beams onto the target in about one hour. At Lawrence Livermore National Laboratory, we have developed a target alignment concept and built a prototype to validate the approach. The concept comprises three systems: the chamber center reference, target alignment sensor, and target alignment beams.

  20. Systems Alignment for Comprehensive Faculty Development in Liberal Arts Colleges

    ERIC Educational Resources Information Center

    Baker, Vicki L.; Lunsford, Laura G.; Pifer, Meghan J.

    2015-01-01

    Using an alignment framework, the authors explore faculty development initiatives in liberal arts colleges in order to understand the connection between organizational priorities and processes as connected to faculty members' stated needs. The study draws on mixed-methods data from The Initiative for Faculty Development in Liberal Arts Colleges…

  1. Characterization of a Nd:YAG doubled pulsed laser system

    NASA Technical Reports Server (NTRS)

    Williams-Byrd, Julie A.; Barnes, James C.; Barnes, Norman P.; Lockard, George; Little, Alan; Banziger, Curtis; Marsh, Waverly; Nichols, Charles

    1992-01-01

    A description of a frequency doubled, double pulsed Nd:YAG laser that is to be used to pump an injection locked Ti:Sapphire power oscillator is presented. These two lasers make up the transmitter portion of the Lidar Atmospheric Sensing Experiment (LAWSE) instrument. LASE is a Lidar/DIAL experiment that is to measure water vapor in the troposphere. By utilizing the twin concept, both pulses can be produced with a single laser system, thereby minimizing cost, size, and weight. Alignment problems associated with having two separate lasers each produce one of the twin pulses are also alleviated. The LASE transmitter consists of a doubled pulsed Nd:YAG laser that will pump a Ti:Sapphire power oscillator that will be injection-locked by a diode laser. The wavelength of the Ti:Sapphire output will be tunable from 813 to 818 nm. A performance summary of the pump laser is given. The data verify that the pump laser can meet the performance requirements to pump the Ti:Sapphire power oscillator.

  2. Laser addressed holographic memory system

    NASA Technical Reports Server (NTRS)

    Gange, R. A.; Wagle, E. M.; Steinmetz, C. C.

    1973-01-01

    Holographic recall and storage system uses red-lipid microcrystalline wax as storage medium. When laser beam strikes wax, its energy heats point of incidence enough to pass wax through transition temperature. Holograph image can then be written or erased in softened wax.

  3. Building blocks for actively-aligned micro-optical systems in rapid prototyping and small series production

    NASA Astrophysics Data System (ADS)

    Böttger, Gunnar; Queisser, Marco; Arndt-Staufenbiel, Norbert; Schröder, Henning; Lang, K.-D.

    2015-03-01

    In recent years there has been considerable progress in utilizing fully automated machines for the assembly of microoptical systems. Such systems integrate laser sources, optical elements and detectors into tight packages, and efficiently couple light to free space beams, waveguides in optical backplanes, or optical fibers for longer reach transmission. The required electrical-optical and optical components are placed and aligned actively in more than one respect. For one, all active components are actually operated in the alignment process, and, more importantly, the placing of all components is controlled actively by camera systems and power detectors with live feedback for an optimal coupling efficiency. The total number of optical components typically is in the range of 5 to 50, whereas the number of actors with gripping tools for the actual handling and aligning is limited, with little flexibility in the gripping width. The assembly process therefore is strictly sequential and, given that an automated tool changing has not been established in this class of machines yet, there are either limitations in the geometries of components that may be used, or time-consuming interaction by human operators is needed. As a solution we propose and present lasered glass building blocks with standardized gripping geometries that enclose optical elements of various shapes and functionalities. These are cut as free form geometries with green short pulse and CO2 lasers. What seems to add cost at first rather increases freedom of design and adds an economical flexibility to create very hybrid assemblies of various micro-optical assemblies also in small numbers.

  4. Aligning Evaluation Results and Professional Development: Driving Systemic Human Capital Management Reform

    ERIC Educational Resources Information Center

    Behrstock-Sherratt, Ellen; Jacques, Catherine

    2012-01-01

    This brief provides district and other educational leaders with research-based information on aligning professional development policies with teacher evaluations to drive more comprehensive human capital management. First, this brief describes an aligned evaluation and professional development system. Next, it discusses existing models and…

  5. State Standards and State Assessment Systems: A Guide to Alignment. Series on Standards and Assessments.

    ERIC Educational Resources Information Center

    La Marca, Paul M.; Redfield, Doris; Winter, Phoebe C.

    Alignment of content standards, performance standards, and assessments is crucial. This guide contains information to assist states and districts in aligning their assessment systems to their content and performance standards. It includes a review of current literature, both published and fugitive. The research is woven together with a few basic…

  6. Emulated laser-acupuncture system.

    PubMed

    Chang, Shu-Chen; Kuo, Che-Chang; Ni, Chien-Hang; Tsai, Chin-Chuan; Yen, San-Fong; Chiu, Ya-Hui; Qu, Ang-Dao; Wang, Chih-Yu

    2014-10-10

    A novel laser-acupuncture system was developed that can be used to implement the manipulation methods of traditional acupuncture, such as lifting and thrusting. A 780 nm laser diode with a maximum power of 90 mW was used as the light source. The focus point of the laser beam was adjustable by changing the position of the lens, facilitating the implementation of the lifting and thrusting methods of traditional Chinese medicine and achieving various stimulation depths at the acupuncture point. The images for the light spots from the outlet of the emulated laser acupuncture were captured at various distances and their sizes were calculated. The result showed that the diameter of the focused light spot (i.e., at the focus point) was 0.11 mm, which is close to the diameter of commonly used needles (with diameters of approximately 0.22 mm). The area of the light spot 1 cm from the focus point was approximately 50 times larger, indicating that the unit power might be 1/50 of the power of the focus point. To study the effect of emulated laser acupuncture on human meridians, after stimulating the Shenmen point (HT7) of five subjects and obtaining their Ryodoraku values of the heart meridian and the small-intestine meridian, a paired t test showed that the laser stimulation incorporating lifting and thrusting was significantly higher than the laser stimulation without lifting and thrusting (p<0.05). The result is consistent with traditional acupuncture in that acupuncture incorporating lift and thrust is more effective than that without lift and thrust. PMID:25322416

  7. Laser illuminator and optical system for disk patterning

    DOEpatents

    Hackel, Lloyd A.; Dane, C. Brent; Dixit, Shamasundar N.; Everett, Mathew; Honig, John

    2000-01-01

    Magnetic recording media are textured over areas designated for contact in order to minimize friction with data transducing heads. In fabricating a hard disk, an aluminum nickel-phosphorous substrate is polished to a specular finish. A mechanical means is then used to roughen an annular area intended to be the head contact band. An optical and mechanical system allows thousands of spots to be generated with each laser pulse, allowing the textured pattern to be rapidly generated with a low repetition rate laser and an uncomplicated mechanical system. The system uses a low power laser, a beam expander, a specially designed phase plate, a prism to deflect the beam, a lens to transmit the diffraction pattern to the far field, a mechanical means to rotate the pattern and a trigger system to fire the laser when sections of the pattern are precisely aligned. The system generates an annular segment of the desired pattern with which the total pattern is generated by rotating the optical system about its optic axis, sensing the rotational position and firing the laser as the annular segment rotates into the next appropriate position. This marking system can be integrated into a disk sputtering system for manufacturing magnetic disks, allowing for a very streamlined manufacturing process.

  8. Reflex ring laser amplifier system

    SciTech Connect

    Summers, M.A.

    1983-08-31

    The invention is a method and apparatus for providing a reflex ring laser system for amplifying an input laser pulse. The invention is particularly useful in laser fusion experiments where efficient production of high-energy and high power laser pulses is required. The invention comprises a large aperture laser amplifier in an unstable ring resonator which includes a combination spatial filter and beam expander having a magnification greater than unity. An input pulse is injected into the resonator, e.g., through an aperture in an input mirror. The injected pulse passes through the amplifier and spatial filter/expander components on each pass around the ring. The unstable resonator is designed to permit only a predetermined number of passes before the amplified pulse exits the resonator. On the first pass through the amplifier, the beam fills only a small central region of the gain medium. On each successive pass, the beam has been expanded to fill the next concentric non-overlapping region of the gain medium.

  9. Ultra-broadband hybrid infrared laser system

    NASA Astrophysics Data System (ADS)

    Budilova, O. V.; Ionin, A. A.; Kinyaevskiy, I. O.; Klimachev, Yu. M.; Kotkov, A. A.; Kozlov, A. Yu.

    2016-03-01

    A hybrid IR laser system consisting of molecular gas lasers with frequency conversion of laser radiation in a solid-state converter (nonlinear crystal) was developed. One of these gas lasers is a carbon monoxide laser operating in multi-line or single-line mode. Another one is a carbon dioxide laser operating in multi-line mode. The two lasers operate under Q-switching with a joint rotating mirror. Due to sum- and difference-frequency generation in nonlinear crystals, the laser system emits within wavelength range from 2.5 to 16.6 μm. The laser system emitting radiation over such an extremely wide wavelength range (2.7 octaves) is of interest for remote sensing and other applications connected with laser beam propagation in the atmosphere.

  10. Variable emissivity laser thermal control system

    DOEpatents

    Milner, J.R.

    1994-10-25

    A laser thermal control system for a metal vapor laser maintains the wall temperature of the laser at a desired level by changing the effective emissivity of the water cooling jacket. This capability increases the overall efficiency of the laser. 8 figs.

  11. Geoscience laser altimeter system - stellar reference system

    SciTech Connect

    Millar, Pamela S.; Sirota, J. Marcos

    1998-01-15

    GLAS is an EOS space-based laser altimeter being developed to profile the height of the Earth's ice sheets with {approx}15 cm single shot accuracy from space under NASA's Mission to Planet Earth (MTPE). The primary science goal of GLAS is to determine if the ice sheets are increasing or diminishing for climate change modeling. This is achieved by measuring the ice sheet heights over Greenland and Antarctica to 1.5 cm/yr over 100 kmx100 km areas by crossover analysis (Zwally 1994). This measurement performance requires the instrument to determine the pointing of the laser beam to {approx}5 urad (1 arcsecond), 1-sigma, with respect to the inertial reference frame. The GLAS design incorporates a stellar reference system (SRS) to relate the laser beam pointing angle to the star field with this accuracy. This is the first time a spaceborne laser altimeter is measuring pointing to such high accuracy. The design for the stellar reference system combines an attitude determination system (ADS) with a laser reference system (LRS) to meet this requirement. The SRS approach and expected performance are described in this paper.

  12. Automated alignment of a reconfigurable optical system using focal-plane sensing and Kalman filtering.

    PubMed

    Fang, Joyce; Savransky, Dmitry

    2016-08-01

    Automation of alignment tasks can provide improved efficiency and greatly increase the flexibility of an optical system. Current optical systems with automated alignment capabilities are typically designed to include a dedicated wavefront sensor. Here, we demonstrate a self-aligning method for a reconfigurable system using only focal plane images. We define a two lens optical system with 8 degrees of freedom. Images are simulated given misalignment parameters using ZEMAX software. We perform a principal component analysis on the simulated data set to obtain Karhunen-Loève modes, which form the basis set whose weights are the system measurements. A model function, which maps the state to the measurement, is learned using nonlinear least-squares fitting and serves as the measurement function for the nonlinear estimator (extended and unscented Kalman filters) used to calculate control inputs to align the system. We present and discuss simulated and experimental results of the full system in operation.

  13. Automated alignment of a reconfigurable optical system using focal-plane sensing and Kalman filtering.

    PubMed

    Fang, Joyce; Savransky, Dmitry

    2016-08-01

    Automation of alignment tasks can provide improved efficiency and greatly increase the flexibility of an optical system. Current optical systems with automated alignment capabilities are typically designed to include a dedicated wavefront sensor. Here, we demonstrate a self-aligning method for a reconfigurable system using only focal plane images. We define a two lens optical system with 8 degrees of freedom. Images are simulated given misalignment parameters using ZEMAX software. We perform a principal component analysis on the simulated data set to obtain Karhunen-Loève modes, which form the basis set whose weights are the system measurements. A model function, which maps the state to the measurement, is learned using nonlinear least-squares fitting and serves as the measurement function for the nonlinear estimator (extended and unscented Kalman filters) used to calculate control inputs to align the system. We present and discuss simulated and experimental results of the full system in operation. PMID:27505378

  14. A vision-aided alignment datum system for coordinate measuring machines

    NASA Astrophysics Data System (ADS)

    Wang, L.; Lin, G. C. I.

    1997-07-01

    This paper presents the development of a CAD-based and vision-aided precision measurement system. A new coordinate system alignment technique for coordinate measuring machines (CMMs) is described. This alignment technique involves a machine vision system with CAD-based planning and execution of inspection. The determination method for measuring datums for the coordinate measuring technique, using the AutoCAD development system, is described in more detail. To improve image quality in the machine vision system, a contrast enhancement technique is used on the image background to reduce image noise, and an on-line calibration technique is applied. Some systematic errors may be caused by imperfect geometric features in components during coordinate system alignment. This measurement system approach, with its new measuring coordinate alignment method, can be used for high-precision measurement to overcome such errors.

  15. Automated alignment of a reconfigurable optical system using focal-plane sensing and Kalman filtering

    NASA Astrophysics Data System (ADS)

    Fang, Joyce; Savransky, Dmitry

    2016-08-01

    Automation of alignment tasks can provide improved efficiency and greatly increase the flexibility of an optical system. Current optical systems with automated alignment capabilities are typically designed to include a dedicated wavefront sensor. Here, we demonstrate a self-aligning method for a reconfigurable system using only focal plane images. We define a two lens optical system with eight degrees of freedom. Images are simulated given misalignment parameters using ZEMAX software. We perform a principal component analysis (PCA) on the simulated dataset to obtain Karhunen-Lo\\`eve (KL) modes, which form the basis set whose weights are the system measurements. A model function which maps the state to the measurement is learned using nonlinear least squares fitting and serves as the measurement function for the nonlinear estimator (Extended and Unscented Kalman filters) used to calculate control inputs to align the system. We present and discuss both simulated and experimental results of the full system in operation.

  16. Parametric infrared tunable laser system

    NASA Technical Reports Server (NTRS)

    Garbuny, M.; Henningsen, T.; Sutter, J. R.

    1980-01-01

    A parametric tunable infrared laser system was built to serve as transmitter for the remote detection and density measurement of pollutant, poisonous, or trace gases in the atmosphere. The system operates with a YAG:Nd laser oscillator amplifier chain which pumps a parametric tunable frequency converter. The completed system produced pulse energies of up to 30 mJ. The output is tunable from 1.5 to 3.6 micrometers at linewidths of 0.2-0.5 /cm (FWHM), although the limits of the tuning range and the narrower line crystals presently in the parametric converter by samples of the higher quality already demonstrated is expected to improve the system performance further.

  17. Alignment of CH3F in para-H2 crystal studied by IR quantum cascade laser polarization spectroscopy

    NASA Astrophysics Data System (ADS)

    Kawasaki, Hiroyuki; Mizoguchi, Asao; Kanamori, Hideto

    2016-05-01

    In order to investigate the alignment of CH3F in para-H2 crystals, high resolution polarization spectroscopy of the ν3 vibrational band is studied using a quantum cascade laser at 1040 cm-1. It is found that the main and satellite series of peaks in the ν3 vibrational band of CH3F have the same polarization dependence. This result supports the previously proposed cluster model with ortho-H2 in first and second nearest neighbor sites. The observed polarization dependence function is well described by a simple six-axis void model in which CH3F is not aligned along the c-axis of the crystal but tilted to 64.9(3)° from it.

  18. Alignment of CH3F in para-H2 crystal studied by IR quantum cascade laser polarization spectroscopy.

    PubMed

    Kawasaki, Hiroyuki; Mizoguchi, Asao; Kanamori, Hideto

    2016-05-14

    In order to investigate the alignment of CH3F in para-H2 crystals, high resolution polarization spectroscopy of the ν3 vibrational band is studied using a quantum cascade laser at 1040 cm(-1). It is found that the main and satellite series of peaks in the ν3 vibrational band of CH3F have the same polarization dependence. This result supports the previously proposed cluster model with ortho-H2 in first and second nearest neighbor sites. The observed polarization dependence function is well described by a simple six-axis void model in which CH3F is not aligned along the c-axis of the crystal but tilted to 64.9(3)° from it.

  19. Note: O-ring stack system for electron gun alignment.

    PubMed

    Park, In-Yong; Cho, Boklae; Han, Cheolsu; Shin, Seungmin; Lee, Dongjun; Ahn, Sang Jung

    2015-01-01

    We present a reliable method for aligning an electron gun which consists of an electron source and lenses by controlling a stack of rubber O-rings in a vacuum condition. The beam direction angle is precisely tilted along two axes by adjusting the height difference of a stack of O-rings. In addition, the source position is shifted in each of three orthogonal directions. We show that the tilting angle and linear shift along the x and y axes as obtained from ten stacked O-rings are ±2.55° and ±2 mm, respectively. This study can easily be adapted to charged particle gun alignment and adjustments of the flange position in a vacuum, ensuring that its results can be useful with regard to electrical insulation between flanges with slight modifications. PMID:25638137

  20. Note: O-ring stack system for electron gun alignment

    NASA Astrophysics Data System (ADS)

    Park, In-Yong; Cho, Boklae; Han, Cheolsu; Shin, Seungmin; Lee, Dongjun; Ahn, Sang Jung

    2015-01-01

    We present a reliable method for aligning an electron gun which consists of an electron source and lenses by controlling a stack of rubber O-rings in a vacuum condition. The beam direction angle is precisely tilted along two axes by adjusting the height difference of a stack of O-rings. In addition, the source position is shifted in each of three orthogonal directions. We show that the tilting angle and linear shift along the x and y axes as obtained from ten stacked O-rings are ±2.55° and ±2 mm, respectively. This study can easily be adapted to charged particle gun alignment and adjustments of the flange position in a vacuum, ensuring that its results can be useful with regard to electrical insulation between flanges with slight modifications.

  1. Note: O-ring stack system for electron gun alignment

    SciTech Connect

    Park, In-Yong; Cho, Boklae; Han, Cheolsu; Shin, Seungmin; Lee, Dongjun; Ahn, Sang Jung

    2015-01-15

    We present a reliable method for aligning an electron gun which consists of an electron source and lenses by controlling a stack of rubber O-rings in a vacuum condition. The beam direction angle is precisely tilted along two axes by adjusting the height difference of a stack of O-rings. In addition, the source position is shifted in each of three orthogonal directions. We show that the tilting angle and linear shift along the x and y axes as obtained from ten stacked O-rings are ±2.55° and ±2 mm, respectively. This study can easily be adapted to charged particle gun alignment and adjustments of the flange position in a vacuum, ensuring that its results can be useful with regard to electrical insulation between flanges with slight modifications.

  2. Underwater laser imaging system (UWLIS)

    SciTech Connect

    DeLong, M.L.; Kulp, T.J.

    1995-03-10

    Practical limitations of underwater imaging systems are reached when the noise in the back scattered radiation generated in the water between the imaging system and the target obscures the spatial contrast and the resolution necessary for target discovery and identification. The advent of high power lasers operating in the oceanic transmission window of the visible spectrum (blue-green portion) has led to improved experimental illumination systems for underwater imaging The properties of laser bearm in range-gated and synchronously scanned devices take advantage of the unique temporal and spatial coherence effect of common volume back scatter to reduce or eliminate noise, increase signal to noise levels. Synchronously scanned systems rely on the highly collimated nature of the laser beam for spatial rejection of common volume back scatter. A synchronous, raster-scanning underwater laser imaging system (UWLIS) has been developed at Lawrence liver-more National Laboratory. The present UWLIS system differs from earlier synchronous scanners in its ability to scan in two dimensions at conventional video frame rate (30 Hz). The imaging performance of the present UWLIS was measured at distances of up to 6.3 AL (at a physical distance of 15.2 meters) during an in-water tank test and 4.5 to 5.0 AL (at a physical distance of 30 meters) during open water oceanic testing. The test results indicate that the UWLIS system is already capable of extending the underwater imaging range beyond that of conventional floodlight illuminated SIT cameras. The real or near real time frame rates of the UWLIS make possible operations in a mode in which the platform speed is randomly varied. This is typical of the operational environment in which the platform is often maneuvered above and around rugged seafloor terrain`s and obstacles.

  3. Construction of a femtosecond laser microsurgery system

    PubMed Central

    Steinmeyer, Joseph D; Gilleland, Cody L; Pardo-Martin, Carlos; Angel, Matthew; Rohde, Christopher B; Scott, Mark A; Yanik, Mehmet Fatih

    2014-01-01

    Femtosecond laser microsurgery is a powerful method for studying cellular function, neural circuits, neuronal injury and neuronal regeneration because of its capability to selectively ablate sub-micron targets in vitro and in vivo with minimal damage to the surrounding tissue. Here, we present a step-by-step protocol for constructing a femtosecond laser microsurgery setup for use with a widely available compound fluorescence microscope. The protocol begins with the assembly and alignment of beam-conditioning optics at the output of a femtosecond laser. Then a dichroic mount is assembled and installed to direct the laser beam into the objective lens of a standard inverted microscope. Finally, the laser is focused on the image plane of the microscope to allow simultaneous surgery and fluorescence imaging. We illustrate the use of this setup by presenting axotomy in Caenorhabditis elegans as an example. This protocol can be completed in 2 d. PMID:20203659

  4. PDV Probe Alignment Technique

    SciTech Connect

    Whitworth, T L; May, C M; Strand, O T

    2007-10-26

    This alignment technique was developed while performing heterodyne velocimetry measurements at LLNL. There are a few minor items needed, such as a white card with aperture in center, visible alignment laser, IR back reflection meter, and a microscope to view the bridge surface. The work was performed on KCP flyers that were 6 and 8 mils wide. The probes used were Oz Optics manufactured with focal distances of 42mm and 26mm. Both probes provide a spot size of approximately 80?m at 1550nm. The 42mm probes were specified to provide an internal back reflection of -35 to -40dB, and the probe back reflections were measured to be -37dB and -33dB. The 26mm probes were specified as -30dB and both measured -30.5dB. The probe is initially aligned normal to the flyer/bridge surface. This provides a very high return signal, up to -2dB, due to the bridge reflectivity. A white card with a hole in the center as an aperture can be used to check the reflected beam position relative to the probe and launch beam, and the alignment laser spot centered on the bridge, see Figure 1 and Figure 2. The IR back reflection meter is used to measure the dB return from the probe and surface, and a white card or similar object is inserted between the probe and surface to block surface reflection. It may take several iterations between the visible alignment laser and the IR back reflection meter to complete this alignment procedure. Once aligned normal to the surface, the probe should be tilted to position the visible alignment beam as shown in Figure 3, and the flyer should be translated in the X and Y axis to reposition the alignment beam onto the flyer as shown in Figure 4. This tilting of the probe minimizes the amount of light from the bridge reflection into the fiber within the probe while maintaining the alignment as near normal to the flyer surface as possible. When the back reflection is measured after the tilt adjustment, the level should be about -3dB to -6dB higher than the probes

  5. Laser power conversion system analysis, volume 2

    NASA Technical Reports Server (NTRS)

    Jones, W. S.; Morgan, L. L.; Forsyth, J. B.; Skratt, J. P.

    1979-01-01

    The orbit-to-ground laser power conversion system analysis investigated the feasibility and cost effectiveness of converting solar energy into laser energy in space, and transmitting the laser energy to earth for conversion to electrical energy. The analysis included space laser systems with electrical outputs on the ground ranging from 100 to 10,000 MW. The space laser power system was shown to be feasible and a viable alternate to the microwave solar power satellite. The narrow laser beam provides many options and alternatives not attainable with a microwave beam.

  6. High power rapidly tunable system for laser cooling.

    PubMed

    Valenzuela, V M; Hernández, L; Gomez, E

    2012-01-01

    We present a laser configuration capable of fast frequency changes with a high power output and a large tuning range. The system integrates frequency tuning with an acousto-optic modulator with a double pass tapered amplifier. A compensation circuit keeps the seed power constant and prevents damage to the amplifier. A single mode fiber decouples the modulation and amplification sections and keeps the alignment fixed. The small power required to saturate the amplifier makes the system very reliable. We use the system to obtain a dipole trap that we image using a beam derived from the same configuration. PMID:22299990

  7. Automated Laser Seeker Performance Evaluation System (ALSPES)

    NASA Astrophysics Data System (ADS)

    Martin, Randal G.; Robinson, Elisa L.

    1988-01-01

    The Automated Laser Seeker Performance Evaluation System (ALSPES), which supports the Hellfire missile and Copperhead projectile laser seekers, is discussed. The ALSPES capabilities in manual and automatic operation are described, and the ALSPES test hardware is examined, including the computer system, the laser/attenuator, optics systems, seeker test fixture, and the measurement and test equipment. The calibration of laser energy and test signals in ALSPES is considered.

  8. Optical design of the National Ignition Facility main laser and switchyard/target area beam transport system

    SciTech Connect

    English, R E; Korniski, R J; Miller, J L; Rodgers, J M

    1998-06-26

    The optical design of the main laser and transport mirror sections of the National Ignition Facility are described. For the main laser the configuration, layout constraints, multiple beam arrangement, pinhole layout and beam paths, clear aperture budget, ray trace models, alignment constraints, lens designs, wavefront performance, and pupil aberrations are discussed. For the transport mirror system the layout, alignment controls and clear aperture budget are describe

  9. Fiber laser coupled optical spark delivery system

    DOEpatents

    Yalin, Azer; Willson, Bryan; Defoort, Morgan; Joshi, Sachin; Reynolds, Adam

    2008-03-04

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  10. High speed laser tomography system.

    PubMed

    Samsonov, D; Elsaesser, A; Edwards, A; Thomas, H M; Morfill, G E

    2008-03-01

    A high speed laser tomography system was developed capable of acquiring three-dimensional (3D) images of optically thin clouds of moving micron-sized particles. It operates by parallel-shifting an illuminating laser sheet with a pair of galvanometer-driven mirrors and synchronously recording two-dimensional (2D) images of thin slices of the imaged volume. The maximum scanning speed achieved was 120,000 slices/s, sequences of 24 volume scans (up to 256 slices each) have been obtained. The 2D slices were stacked to form 3D images of the volume, then the positions of the particles were identified and followed in the consecutive scans. The system was used to image a complex plasma with particles moving at speeds up to cm/s.

  11. High speed laser tomography system.

    PubMed

    Samsonov, D; Elsaesser, A; Edwards, A; Thomas, H M; Morfill, G E

    2008-03-01

    A high speed laser tomography system was developed capable of acquiring three-dimensional (3D) images of optically thin clouds of moving micron-sized particles. It operates by parallel-shifting an illuminating laser sheet with a pair of galvanometer-driven mirrors and synchronously recording two-dimensional (2D) images of thin slices of the imaged volume. The maximum scanning speed achieved was 120,000 slices/s, sequences of 24 volume scans (up to 256 slices each) have been obtained. The 2D slices were stacked to form 3D images of the volume, then the positions of the particles were identified and followed in the consecutive scans. The system was used to image a complex plasma with particles moving at speeds up to cm/s. PMID:18377040

  12. In Situ alignment system for phase-shifting point-diffraction interferometry

    DOEpatents

    Goldberg, Kenneth Alan; Naulleau, Patrick P.

    2000-01-01

    A device and method to facilitate the gross alignment of patterned object- and image-plane masks in optical systems such as the phase-shifting point diffraction interferometer are provided. When an array of similar pinholes or discreet mask fields is used, confusion can occur over the alignment of the focused beams within the field. Adding to the mask pattern a circumscribed or inscribed set of symbols that are identifiable in situ facilitates the unambiguous gross alignment of the object- and/or image-plane masks. Alternatively, a system of markings can be encoded directly into the window shape to accomplish this same task.

  13. Computer-aided alignment of off-axis three-mirror imaging spectrometer system

    NASA Astrophysics Data System (ADS)

    Gong, Dun; Wang, Hong; Tian, Tie-yin

    2013-08-01

    The space camera is one of the most advanced optical equipments in obtaining earth surface information from space. With the development of the optical design, manufacture and alignment technology, the performance of the optical camera is moving forward quickly. In spaceto- ground remote sensing field, the resolution of ground remote sensing images have become higher and higher. Off-axis three-mirror system becomes an advanced optical system structure of space camera at present , because of its merits of large field, long focal length, no obstruction, high modulated transfer function, wide spectrum, good image quality, small cubage and light weight, etc. As it is difficult to align and test, the alignment of off-axis three mirror system is timeconsuming, so it is important and necessary of studying the computer-aided alignment of the complex optical system. Aiming at cutting the time of alignment, Computer-aided alignment technology is applied to this system. According to relation between fringe Zernike coefficient and Seidel aberration, wavefront aberration in the exit pupil of optical system is instead with fringe Zernike coefficient. A series of Zernike coefficient expressing the incorrect parameters of system are obtained by using multi-fields ZYGO interferometer auto-collimating interference test, which are transformed into geometric aberrations as the corrected object. Incorrect parameters of the system are determined by sensitivity matrix resulted from optical design software. These incorrect parameters are defined to be variables; the Zernike coefficient are defined to be the optimized target in merit function. The system is optimized by applying optical design software to receive the incorrect parameters result. Consequently, the adjusted result is brought into the optical design software to verify the right selection of incorrect parameters. The practical experiments are also given, result with RMS value lower than 0.04λ is acquired by using this

  14. Developing Secure Power Systems Professional Competence: Alignment and Gaps in Workforce Development Programs—Summary Report

    SciTech Connect

    O'Neil, Lori Ross; Assante, Michael; Tobey, D. H.; Conway, T. J.; Vanderhorst, Jr, T. J.; Januszewski, III, J.; Leo, R.; Perman, K.

    2013-07-01

    This document is a summarization of the report, Developing Secure Power Systems Professional Competence: Alignment and Gaps in Workforce Development Programs, the final report for phase 2 of the SPSP (DOE workforce study) project.

  15. In-flight angular alignment of inertial navigation systems by means of radio aids

    NASA Technical Reports Server (NTRS)

    Tanner, W.

    1972-01-01

    The principles involved in the angular alignment of the inertial reference by nondirectional data from radio aids are developed and compared with conventional methods of alignment such as gyro-compassing and pendulous vertical determination. The specific problem is considered of the space shuttle reentry and a proposed technique for the alignment of the inertial reference system some time before landing. A description is given of the digital simulation of a transponder interrogation system and of its interaction with the inertial navigation system. Data from reentry simulations are used to demonstrate the effectiveness of in-flight inertial system alignment. Concluding remarks refer to other potential applications such as space shuttle orbit insertion and air navigation of conventional aircraft.

  16. High power laser perforating tools and systems

    SciTech Connect

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2014-04-22

    ystems devices and methods for the transmission of 1 kW or more of laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser perforation of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to perforate such boreholes.

  17. Alignment of the measurement scale mark during immersion hydrometer calibration using an image processing system.

    PubMed

    Peña-Perez, Luis Manuel; Pedraza-Ortega, Jesus Carlos; Ramos-Arreguin, Juan Manuel; Arriaga, Saul Tovar; Fernandez, Marco Antonio Aceves; Becerra, Luis Omar; Hurtado, Efren Gorrostieta; Vargas-Soto, Jose Emilio

    2013-10-24

    The present work presents an improved method to align the measurement scale mark in an immersion hydrometer calibration system of CENAM, the National Metrology Institute (NMI) of Mexico, The proposed method uses a vision system to align the scale mark of the hydrometer to the surface of the liquid where it is immersed by implementing image processing algorithms. This approach reduces the variability in the apparent mass determination during the hydrostatic weighing in the calibration process, therefore decreasing the relative uncertainty of calibration.

  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. Ionization and high-order harmonic generation in aligned benzene by a short intense circularly polarized laser pulse

    SciTech Connect

    Baer, Roi; Neuhauser, Daniel; Zdanska, Petra R.; Moiseyev, Nimrod

    2003-10-01

    We present a first-principles study of ionization and high-order harmonic generation by benzene aligned in the polarization plane of a short circularly polarized laser pulse. Time-dependent density-functional theory within the adiabatic local-density approximation is employed to describe the 30 valence-electron dynamics in three dimensions. The multielectron approach enables us to study the effect of very strong laser fields, 10{sup 14}-10{sup 15} W cm{sup -2}, where multiple ionization and high-order harmonic generation interplay. Large ionization currents are formed, causing ionization of 1-4 electron charges, while strong high-order harmonic generation is observed. The well-known recollision mechanism of high-order harmonic generation plays a part for moderate laser intensities but is fully suppressed for strong laser fields. The harmonic generation spectra are characterized by two distinguishable plateaus, where the structure of the first plateau is dominated by the 6k{+-}1 (k=0,1,...) selection rule. The number of harmonics in the second plateau is insensitive to the duration of the pulse. The peaks appear in pairs or in threesomes, depending on the pulse duration.

  20. Volumetric Heating of Ultra-High Energy Density Relativistic Plasmas by Ultrafast Laser Irradiation of Aligned Nanowire Arrays

    NASA Astrophysics Data System (ADS)

    Bargsten, Clayton; Hollinger, Reed; Shlyaptsev, Vyacheslav; Pukhov, Alexander; Keiss, David; Townsend, Amanda; Wang, Yong; Wang, Shoujun; Prieto, Amy; Rocca, Jorge

    2014-10-01

    We have demonstrated the volumetric heating of near-solid density plasmas to keV temperatures by ultra-high contrast femtosecond laser irradiation of arrays of vertically aligned nanowires with an average density up to 30% solid density. X-ray spectra show that irradiation of Ni and Au nanowire arrays with laser pulses of relativistic intensities ionizes plasma volumes several micrometers in depth to the He-like and Co-like (Au 52 +) stages respectively. The penetration depth of the heat into the nanowire array was measured monitoring He-like Co lines from irradiated arrays in which the nanowires are composed of a Co segment buried under a selected length of Ni. The measurement shows the ionization reaches He-like Co for depth of up to 5 μm within the target. This volumetric plasma heating approach creates a new laboratory plasma regime in which extreme plasma parameters can be accessed with table-top lasers. Scaling to higher laser intensities promises to create plasmas with temperatures and pressures approaching those in the center of the sun. Work supported by the U.S Department of Energy, Fusion Energy Sciences and the Defense Threat Reduction Agency grant HDTRA-1-10-1-0079. A.P was supported by of DFG-funded project TR18.

  1. Airborne laser sensors and integrated systems

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark A.; Gardi, Alessandro; Ramasamy, Subramanian

    2015-11-01

    The underlying principles and technologies enabling the design and operation of airborne laser sensors are introduced and a detailed review of state-of-the-art avionic systems for civil and military applications is presented. Airborne lasers including Light Detection and Ranging (LIDAR), Laser Range Finders (LRF), and Laser Weapon Systems (LWS) are extensively used today and new promising technologies are being explored. Most laser systems are active devices that operate in a manner very similar to microwave radars but at much higher frequencies (e.g., LIDAR and LRF). Other devices (e.g., laser target designators and beam-riders) are used to precisely direct Laser Guided Weapons (LGW) against ground targets. The integration of both functions is often encountered in modern military avionics navigation-attack systems. The beneficial effects of airborne lasers including the use of smaller components and remarkable angular resolution have resulted in a host of manned and unmanned aircraft applications. On the other hand, laser sensors performance are much more sensitive to the vagaries of the atmosphere and are thus generally restricted to shorter ranges than microwave systems. Hence it is of paramount importance to analyse the performance of laser sensors and systems in various weather and environmental conditions. Additionally, it is important to define airborne laser safety criteria, since several systems currently in service operate in the near infrared with considerable risk for the naked human eye. Therefore, appropriate methods for predicting and evaluating the performance of infrared laser sensors/systems are presented, taking into account laser safety issues. For aircraft experimental activities with laser systems, it is essential to define test requirements taking into account the specific conditions for operational employment of the systems in the intended scenarios and to verify the performance in realistic environments at the test ranges. To support the

  2. Note: A simple sample transfer alignment for ultra-high vacuum systems

    NASA Astrophysics Data System (ADS)

    Tamtögl, A.; Carter, E. A.; Ward, D. J.; Avidor, N.; Kole, P. R.; Jardine, A. P.; Allison, W.

    2016-06-01

    The alignment of ultra-high-vacuum sample transfer systems can be problematic when there is no direct line of sight to assist the user. We present the design of a simple and cheap system which greatly simplifies the alignment of sample transfer devices. Our method is based on the adaptation of a commercial digital camera which provides live views from within the vacuum chamber. The images of the camera are further processed using an image recognition and processing code which determines any misalignments and reports them to the user. Installation has proven to be extremely useful in order to align the sample with respect to the transfer mechanism. Furthermore, the alignment software can be easily adapted for other systems.

  3. Alignment effects in two-photon double ionization of H{sub 2} in femtosecond xuv laser pulses

    SciTech Connect

    Guan Xiaoxu; Bartschat, Klaus; Schneider, Barry I.

    2011-09-15

    Triple-differential cross sections for two-photon double ionization of the aligned hydrogen molecule at the equilibrium distance are presented for a central photon energy of 30 eV. The temporal response of the laser-driven molecule is investigated by solving the time-dependent Schroedinger equation in full dimensionality using two-center elliptical coordinates and a finite-element discrete-variable-representation approach. The molecular orientation is found to have a strong effect on the emission modes of the two correlated photoelectrons. This molecular effect is most noticeable when the molecular axis and the laser polarization vector are oriented parallel to each other. For intermediate cases between the parallel and perpendicular geometries, the dominant emission modes for two-electron ejection oscillate between those for the two extreme cases. The contributions from different ionization channels are also analyzed in detail. Depending on the emission direction of the reference electron, the interference contributions from the various channels can be constructive or destructive at small alignment angles, while they always contribute constructively to the triple-differential cross sections near the perpendicular geometry.

  4. Laser Safety Audit and Inventory System Database

    SciTech Connect

    AUGUSTONI, ARNOLD L.

    2003-05-01

    A laser safety auditing and inventory system has been in use at Sandia National Laboratories--Albuquerque for the past five years and has recently been considered for adoption by Sandia National Laboratories--Livermore. The system utilizes the ''Microsoft Access'' database application, part of the Office 2000 software package. Audit and inventory data is available on-line for ready access by laser users. Data is updated weekly to provide users with current information relating to laser facility audits and laser inventories.

  5. Geometric phases for laser-induced aligned pendular states of linear molecules

    SciTech Connect

    Aleynikov, Dmitriy V.

    2006-02-15

    Geometric phases may arise in a linear molecule interacting via its anisotropic polarizability with a strong nonresonant laser field. When the polarization vector of laser radiation undergoes cyclic evolution, the molecule returns to its original state but may acquire a Berry or Aharonov-Anandan phase factor.

  6. Laser docking system flight experiment

    NASA Technical Reports Server (NTRS)

    Erwin, Harry O.

    1986-01-01

    Experiments necessary in the development of the Laser Docking System (LDS) are described. The LDS would be mounted in the Orbiter payload bay, along with a grid connected by fiber optic link to a computer in the cabin. The tests would be performed to aid in the design of an operational sensor which could track a passive target accurately enough to permit soft docking. Additional data would be gained regarding the LDS performance in space, the effects of Orbiter RCS plume impingement on the target, and refinements needed for the flight hardware. A working model which includes an IR laser steered by galvanometer-driven motors for bouncing beams off retroreflectors mounted on targets is described, together with a 300 ft long indoor test facility. Tests on Orbiter flights would first be in a wholly automatic mode and then in a man-in-the-loop mode.

  7. Integration, alignment, and verification of optical system assembly for FORMOSAT-5

    NASA Astrophysics Data System (ADS)

    Chen, Ching-Wei; Huang, Po-Hsuan; Chen, Chia-Ray; Chan, Chia-Yen; Lien, Chun-Chieh; Huang, Po-Han; Hsu, Ming-Ying; Chang, Shenq-Tsong; Huang, Ting-Ming

    2014-09-01

    FORMOSAT-5 consists of a spacecraft bus and an electro-optical payload. The payload is an f/8 Cassegrain type telescope with 3.6-m effective focal length. The spacecraft has a ground sampling distance of 2-m for panchromatic and 4-m for multispectral bands, with a 24-km swath width. FORMOSAT-5 is the first space program that National Space Organization (NSPO) takes full responsibility for the complete satellite and payload system engineering. The optical system assembly (OSA) has been successfully aligned and is now undergoing final performance verification tests at system level. To help create this unique instrument, NSPO has developed the computer aided alignment method assisted with the mechanical ground support equipment to carry out the assembly, alignment, and verification of the complex systems. This method offers an integrated capability for interferometric alignment and characterization of the large instrument. A detail OSA integration and verification steps, including primary mirror, secondary mirror, corrector lens and baffles alignment are presented. This paper describes the overall capability of this method and uses decomposed Zernike polynomials from the alignment and characterization of the OSA to verify the reduction of the wavefront errors and misalignments. It further demonstrates the successful completion of the instrument and satisfaction with the main system requirements.

  8. Short-pulse Laser Capability on the Mercury Laser System

    SciTech Connect

    Ebbers, C; Armstrong, P; Bayramian, A; Barty, C J; Bibeau, C; Britten, J; Caird, J; Campbell, R; Chai, B; Crane, J; Cross, R; Erlandson, A; Fei, Y; Freitas, B; Jovanovic, I; Liao, Z; Molander, B; Schaffers, K; Stuart, B; Sutton, S; Ladran, T; Telford, S; Thelin, P; Utterback, E

    2006-06-22

    Applications using high energy ''petawatt-class'' laser drivers operating at repetition rates beyond 0.01 Hz are only now being envisioned. The Mercury laser system is designed to operate at 100 J/pulse at 10 Hz. We investigate the potential of configuring the Mercury laser to produce a rep-rated, ''petawatt-class'' source. The Mercury laser is a prototype of a high energy, high repetition rate source (100 J, 10 Hz). The design of the Mercury laser is based on the ability to scale in energy through scaling in aperture. Mercury is one of several 100 J, high repetition rate (10 Hz) lasers sources currently under development (HALNA, LUCIA, POLARIS). We examine the possibility of using Mercury as a pump source for a high irradiance ''petawatt-class'' source: either as a pump laser for an average power Ti:Sapphire laser, or as a pump laser for OPCPA based on YCa{sub 4}O(BO{sub 3}){sub 3} (YCOB), ideally producing a source approaching 30 J /30 fs /10 Hz--a high repetition rate petawatt. A comparison of the two systems with nominal configurations and efficiencies is shown in Table 1.

  9. Self-aligning amelogenin nanoribbons in oil-water system

    PubMed Central

    He, Xiaodong; Wu, Shenping; Martinez-Avila, Olga; Cheng, Yifan; Habelitz, Stefan

    2010-01-01

    The highly organized microstructure of dental enamel is a result of protein-guided anisotropic growth of apatite nanofibers. It is established that amelogenin proteins, the main constituent of the developing enamel matrix, form nanospheres in vitro, but the amphiphilic nature of the full-length protein conveys the possibility of generating more complex structures as observed with other surfactant-like molecules. This study tested if the use of metastable oil-water emulsions can induce supramolecular assemblies of amelogenin. Recombinant full-length amelogenin, rH174, was mixed into octanol/ethyl acetate preparations of different ratios to form emulsions at pH 4.5 and 7.4. Atomic force and electron microscopy showed the formation of 16.7±1.0 nm wide nanoribbons which grew to several micrometer length over a period of days. Nanoribbons formed from reverse micelles by enabling hydrophobic tails of the molecules to interact while preventing the formation of amelogenin nanospheres. Ribbon formation required the presence of calcium and phosphate ions and may be localized at a dark central line along the amelogenin ribbons. The ribbons have a strong tendency to align in parallel maintaining 5 to 20nm space between each other. The growth rates and number of ribbons were significantly higher at pH 4.5 and related to the metastability of the emulsion. A model for ribbon extension proposes the addition of short segments or amelogenin dimers to the ends of the ribbon. The formation of self-aligning and uniaxially elongating amelogenin structures triggered by the presence of calcium and phosphate may represent a suitable new model for protein controlled mineralization in enamel. PMID:21134461

  10. The Injection Laser System on the National Ignition Facility

    SciTech Connect

    Bowers, M; Burkhart, S; Cohen, S; Erbert, G; Heebner, J; Hermann, M; Jedlovec, D

    2006-12-13

    The National Ignition Facility (NIF) is currently the largest and most energetic laser system in the world. The main amplifiers are driven by the Injection Laser System comprised of the master oscillators, optical preamplifiers, temporal pulse shaping and spatial beam formatting elements and injection diagnostics. Starting with two fiber oscillators separated by up to a few angstroms, the pulse is phase modulated to suppress SBS and enhance spatial smoothing, amplified, split into 48 individual fibers, and then temporally shaped by an arbitrary waveform generator. Residual amplitude modulation induced in the preamplifiers from the phase modulation is also precompensated in the fiber portion of the system before it is injected into the 48 pre-amplifier modules (PAMs). Each of the PAMs amplifies the light from the 1 nJ fiber injection up to the multi-joule level in two stages. Between the two stages the pre-pulse is suppressed by 60 dB and the beam is spatially formatted to a square aperture with precompensation for the nonuniform gain profile of the main laser. The input sensor package is used to align the output of each PAM to the main laser and acquire energy, power, and spatial profiles for all shots. The beam transport sections split the beam from each PAM into four main laser beams (with optical isolation) forming the 192 beams of the NIF. Optical, electrical, and mechanical design considerations for long term reliability and availability will be discussed.

  11. Drive system alignment calibration of a microgravity drop tower of novel design

    NASA Astrophysics Data System (ADS)

    Trunins, J.; Osborne, B. P.; Augousti, A.

    2013-06-01

    We report here the calibration of the drive system of a new scientific facility for production of microgravity, operating on a novel design of electromagnetically driven platform. The construction achieves the design specification of alignment of the guide rails to better than 0.254mm across the entire guide rail height of 8m, despite a small lean to the right (within tolerance) and it was noted that this alignment is improved by the presence of the trolley that carries the platform.

  12. Experimental findings on the underwater measurements uncertainty of speed of sound and the alignment system

    NASA Astrophysics Data System (ADS)

    Santos, T. Q.; Alvarenga, A. V.; Oliveira, D. P.; Mayworm, R. C.; Souza, R. M.; Costa-Félix, R. P. B.

    2016-07-01

    Speed of sound is an important quantity to characterize reference materials for ultrasonic applications, for instance. The alignment between the transducer and the test body is an key activity in order to perform reliable and consistent measurement. The aim of this work is to evaluate the influence of the alignment system to the expanded uncertainty of such measurement. A stainless steel cylinder was previously calibrated on an out of water system typically used for calibration of non-destructive blocks. Afterwards, the cylinder was calibrated underwater with two distinct alignment system: fixed and mobile. The values were statistically compared to the out-of-water measurement, considered the golden standard for such application. For both alignment systems, the normalized error was less than 0.8, leading to conclude that the both measurement system (under and out-of-water) do not diverge significantly. The gold standard uncertainty was 2.7 m-s-1, whilst the fixed underwater system resulted in 13 m-s-1, and the mobile alignment system achieved 6.6 m-s-1. After the validation of the underwater system for speed of sound measurement, it will be applied to certify Encapsulated Tissue Mimicking Material as a reference material for biotechnology application.

  13. Numerical simulation of imaging laser radar system

    NASA Astrophysics Data System (ADS)

    Han, Shaokun; Lu, Bo; Jiang, Ming; Liu, Xunliang

    2008-03-01

    Rational and effective design of imaging laser radar systems is the key of imaging laser radar system research. Design must fully consider the interrelationship between various parameters. According to the parameters, choose suitable laser, detector and other components. To use of mathematical modeling and computer simulation is an effective imaging laser radar system design methods. This paper based on the distance equation, using the detection statistical methods, from the laser radar range coverage, detection probability, false-alarm rate, SNR to build the laser radar system mathematical models. In the process of setting up the mathematical models to fully consider the laser, atmosphere, detector and other factors on the performance that is to make the models be able to respond accurately the real situation. Based on this using C# and Matlab designed a simulation software.

  14. Precision laser automatic tracking system.

    PubMed

    Lucy, R F; Peters, C J; McGann, E J; Lang, K T

    1966-04-01

    A precision laser tracker has been constructed and tested that is capable of tracking a low-acceleration target to an accuracy of about 25 microrad root mean square. In tracking high-acceleration targets, the error is directly proportional to the angular acceleration. For an angular acceleration of 0.6 rad/sec(2), the measured tracking error was about 0.1 mrad. The basic components in this tracker, similar in configuration to a heliostat, are a laser and an image dissector, which are mounted on a stationary frame, and a servocontrolled tracking mirror. The daytime sensitivity of this system is approximately 3 x 10(-10) W/m(2); the ultimate nighttime sensitivity is approximately 3 x 10(-14) W/m(2). Experimental tests were performed to evaluate both dynamic characteristics of this system and the system sensitivity. Dynamic performance of the system was obtained, using a small rocket covered with retroreflective material launched at an acceleration of about 13 g at a point 204 m from the tracker. The daytime sensitivity of the system was checked, using an efficient retroreflector mounted on a light aircraft. This aircraft was tracked out to a maximum range of 15 km, which checked the daytime sensitivity of the system measured by other means. The system also has been used to track passively stars and the Echo I satellite. Also, the system tracked passively a +7.5 magnitude star, and the signal-to-noise ratio in this experiment indicates that it should be possible to track a + 12.5 magnitude star.

  15. System-size dependent band alignment in lateral two-dimensional heterostructures

    NASA Astrophysics Data System (ADS)

    Leenaerts, O.; Vercauteren, S.; Schoeters, B.; Partoens, B.

    2016-06-01

    The electronic band alignment in semiconductor heterostructures is a key factor for their use in electronic applications. The alignment problem has been intensively studied for bulk systems but is less well understood for low-dimensional heterostructures. In this work we investigate the alignment in two-dimensional lateral heterostructures. First-principles calculations are used to show that the electronic band offset depends crucially on the width and thickness of the heterostructure slab. The particular heterostructures under study consist of thin hydrogenated and fluorinated diamond slabs which are laterally joined together. Two different limits for the band offset are observed. For infinitely wide heterostructures the vacuum potential above the two materials is aligned leading to a large step potential within the heterostructure. For infinitely thick heterostructure slabs, on the other hand, there is no potential step in the heterostructure bulk, but a large potential step in the vacuum region above the heterojunction is observed. The band alignment in finite systems depends on the particular dimensions of the system. These observations are shown to result from an interface dipole at the heterojunction that tends to align the band structures.

  16. Alignment dependence in the breakup of the H2 molecule by an xuv laser pulse

    NASA Astrophysics Data System (ADS)

    Guan, Xiaoxu; Bartschat, Klaus; Schneider, Barry I.

    2012-11-01

    We present theoretical predictions for the angular distribution of the ejected electrons in two-photon double-ionization of H2 by an xuv laser pulse. The results were obtained by solving the time-dependent Schrödinger equation in prolate spheroidal coordinates. We find a strong dependence of the emission pattern on the relative orientation of the laser polarization vector and the molecular axis.

  17. High power laser apparatus and system

    NASA Technical Reports Server (NTRS)

    Evans, J. C., Jr.; Brandhorst, H. W., Jr. (Inventor)

    1975-01-01

    A high-power, continuous-wave laser was designed for use in power transmission and energy-collecting systems, and for producing incoherent light for pumping a laser material. The laser has a high repetitive pulsing rate per unit time, resulting in a high-power density beam. The laser is composed of xenon flash tubes powered by fast-charging capacitors flashed in succession by a high-speed motor connected to an automobile-type distributor.

  18. Fission fragment excited laser system

    DOEpatents

    McArthur, David A.; Tollefsrud, Philip B.

    1976-01-01

    A laser system and method for exciting lasing action in a molecular gas lasing medium which includes cooling the lasing medium to a temperature below about 150 K and injecting fission fragments through the lasing medium so as to preferentially excite low lying vibrational levels of the medium and to cause population inversions therein. The cooled gas lasing medium should have a mass areal density of about 5 .times. 10.sup.-.sup.3 grams/square centimeter, relaxation times of greater than 50 microseconds, and a broad range of excitable vibrational levels which are excitable by molecular collisions.

  19. Development of laser beam injection system for the Edge Thomson Scattering (ETS) in ITER

    NASA Astrophysics Data System (ADS)

    Yatsuka, E.; Hatae, T.; Suitoh, S.; Ohara, M.; Hagita, K.; Inoue, K.; Bassan, M.; Walsh, M.; Itami, K.

    2016-01-01

    This paper focuses on the design and development of the laser injection system for the ITER Edge Thomson Scattering system (ETS). The ITER ETS achieves a temporal resolution of 100 Hz by firing two 50 Hz laser beams alternatively. The use of dual lasers enables us to perform the Thomson scattering measurements at a temporal resolution of 50 Hz in case that one of the laser systems stops functioning. A new type of beam combiner was developed to obtain a single beam that is collinear and fixed linearly polarized from two laser beams using a motor-driven rotating half-wave plate. The rotating half-wave plate method does not induce misalignment even if the rotating mechanism malfunctions. The combined beam is relayed from the diagnostic hall to the plasma using mirror optics and is absorbed at the beam dump integrated on the inner blanket. The beam alignment system was designed to direct the laser beam onto the center of the beam dump head. The beam position at the beam dump is monitored by four alignment laser beams which propagate parallel to the diagnostic Nd:YAG laser beam and imaging systems installed outside the diagnostic port.

  20. Laser Doppler And Range Systems For Spacecraft

    NASA Technical Reports Server (NTRS)

    Kinman, P. W.; Gagliardi, R. M.

    1990-01-01

    Report discusses two types of proposed laser systems containing active transponders measuring distance (range) and line-of-sight velocity (via Doppler effect) between deep space vehicle and earth-orbiting satellite. Laser system offers diffraction advantage over microwave system. Delivers comparable power to distant receiver while using smaller transmitting and receiving antennas and less-powerful transmitter. Less subject to phase scintillations caused by passage through such inhomogeneous media as solar corona. One type of system called "incoherent" because range and Doppler measurements do not require coherence with laser carrier signals. Other type of system called "coherent" because successful operation requires coherent tracking of laser signals.

  1. Retrieving transient conformational molecular structure information from inner-shell photoionization of laser-aligned molecules

    DOE PAGES

    Wang, Xu; Le, Anh -Thu; Yu, Chao; Lucchese, R. R.; Lin, C. D.

    2016-03-30

    We discuss a scheme to retrieve transient conformational molecular structure information using photoelectron angular distributions (PADs) that have averaged over partial alignments of isolated molecules. The photoelectron is pulled out from a localized inner-shell molecular orbital by an X-ray photon. We show that a transient change in the atomic positions from their equilibrium will lead to a sensitive change in the alignment-averaged PADs, which can be measured and used to retrieve the former. Exploiting the experimental convenience of changing the photon polarization direction, we show that it is advantageous to use PADs obtained from multiple photon polarization directions. Lastly, amore » simple single-scattering model is proposed and benchmarked to describe the photoionization process and to do the retrieval using a multiple-parameter fitting method.« less

  2. Retrieving transient conformational molecular structure information from inner-shell photoionization of laser-aligned molecules.

    PubMed

    Wang, Xu; Le, Anh-Thu; Yu, Chao; Lucchese, R R; Lin, C D

    2016-01-01

    We discuss a scheme to retrieve transient conformational molecular structure information using photoelectron angular distributions (PADs) that have averaged over partial alignments of isolated molecules. The photoelectron is pulled out from a localized inner-shell molecular orbital by an X-ray photon. We show that a transient change in the atomic positions from their equilibrium will lead to a sensitive change in the alignment-averaged PADs, which can be measured and used to retrieve the former. Exploiting the experimental convenience of changing the photon polarization direction, we show that it is advantageous to use PADs obtained from multiple photon polarization directions. A simple single-scattering model is proposed and benchmarked to describe the photoionization process and to do the retrieval using a multiple-parameter fitting method. PMID:27025410

  3. Retrieving transient conformational molecular structure information from inner-shell photoionization of laser-aligned molecules

    PubMed Central

    Wang, Xu; Le, Anh-Thu; Yu, Chao; Lucchese, R. R.; Lin, C. D.

    2016-01-01

    We discuss a scheme to retrieve transient conformational molecular structure information using photoelectron angular distributions (PADs) that have averaged over partial alignments of isolated molecules. The photoelectron is pulled out from a localized inner-shell molecular orbital by an X-ray photon. We show that a transient change in the atomic positions from their equilibrium will lead to a sensitive change in the alignment-averaged PADs, which can be measured and used to retrieve the former. Exploiting the experimental convenience of changing the photon polarization direction, we show that it is advantageous to use PADs obtained from multiple photon polarization directions. A simple single-scattering model is proposed and benchmarked to describe the photoionization process and to do the retrieval using a multiple-parameter fitting method. PMID:27025410

  4. Laser-pointer-induced self-focusing effect in hybrid-aligned dye-doped liquid crystals

    PubMed Central

    Wang, Jing; Aihara, Yosuke; Kinoshita, Motoi; Mamiya, Jun-ichi; Priimagi, Arri; Shishido, Atsushi

    2015-01-01

    Nonlinear optics deals with phenomena where “light controls light”; e.g., there is mediation by an intensity-dependent medium through which light propagates. This field has attracted much attention for its immense potential in applications dependent on nonlinear processes, such as frequency conversion, multiple-photon absorption, self-phase modulation, and so on. However, such nonlinearities are typically only observed at very high light intensities and thus they require costly lasers. Here, we report on a self-focusing effect induced with a 1 mW handheld laser pointer. We prepared polymer-stabilized dye-doped liquid crystals, in which the molecular director orientation gradually changes from homeotropic at one surface to homogeneous at the other. This is referred to as hybrid alignment. In such films, the threshold intensity needed to form diffraction rings was reduced by a factor of 8.5 compared to that in conventional homeotropic cells, which enabled the induction of the self-focusing effect with a laser pointer. PMID:25944052

  5. Laser-pointer-induced self-focusing effect in hybrid-aligned dye-doped liquid crystals

    NASA Astrophysics Data System (ADS)

    Wang, Jing; Aihara, Yosuke; Kinoshita, Motoi; Mamiya, Jun-Ichi; Priimagi, Arri; Shishido, Atsushi

    2015-05-01

    Nonlinear optics deals with phenomena where “light controls light” e.g., there is mediation by an intensity-dependent medium through which light propagates. This field has attracted much attention for its immense potential in applications dependent on nonlinear processes, such as frequency conversion, multiple-photon absorption, self-phase modulation, and so on. However, such nonlinearities are typically only observed at very high light intensities and thus they require costly lasers. Here, we report on a self-focusing effect induced with a 1 mW handheld laser pointer. We prepared polymer-stabilized dye-doped liquid crystals, in which the molecular director orientation gradually changes from homeotropic at one surface to homogeneous at the other. This is referred to as hybrid alignment. In such films, the threshold intensity needed to form diffraction rings was reduced by a factor of 8.5 compared to that in conventional homeotropic cells, which enabled the induction of the self-focusing effect with a laser pointer.

  6. Laser-pointer-induced self-focusing effect in hybrid-aligned dye-doped liquid crystals.

    PubMed

    Wang, Jing; Aihara, Yosuke; Kinoshita, Motoi; Mamiya, Jun-Ichi; Priimagi, Arri; Shishido, Atsushi

    2015-01-01

    Nonlinear optics deals with phenomena where "light controls light"; e.g., there is mediation by an intensity-dependent medium through which light propagates. This field has attracted much attention for its immense potential in applications dependent on nonlinear processes, such as frequency conversion, multiple-photon absorption, self-phase modulation, and so on. However, such nonlinearities are typically only observed at very high light intensities and thus they require costly lasers. Here, we report on a self-focusing effect induced with a 1 mW handheld laser pointer. We prepared polymer-stabilized dye-doped liquid crystals, in which the molecular director orientation gradually changes from homeotropic at one surface to homogeneous at the other. This is referred to as hybrid alignment. In such films, the threshold intensity needed to form diffraction rings was reduced by a factor of 8.5 compared to that in conventional homeotropic cells, which enabled the induction of the self-focusing effect with a laser pointer. PMID:25944052

  7. Laser spark distribution and ignition system

    DOEpatents

    Woodruff, Steven; McIntyre, Dustin L.

    2008-09-02

    A laser spark distribution and ignition system that reduces the high power optical requirements for use in a laser ignition and distribution system allowing for the use of optical fibers for delivering the low peak energy pumping pulses to a laser amplifier or laser oscillator. An optical distributor distributes and delivers optical pumping energy from an optical pumping source to multiple combustion chambers incorporating laser oscillators or laser amplifiers for inducing a laser spark within a combustion chamber. The optical distributor preferably includes a single rotating mirror or lens which deflects the optical pumping energy from the axis of rotation and into a plurality of distinct optical fibers each connected to a respective laser media or amplifier coupled to an associated combustion chamber. The laser spark generators preferably produce a high peak power laser spark, from a single low power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced breakdown spectroscopy diagnostic sensors.

  8. Coherent laser vision system (CLVS)

    SciTech Connect

    1997-02-13

    The purpose of the CLVS research project is to develop a prototype fiber-optic based Coherent Laser Vision System suitable for DOE`s EM Robotics program. The system provides three-dimensional (3D) vision for monitoring situations in which it is necessary to update geometric data on the order of once per second. The CLVS project plan required implementation in two phases of the contract, a Base Contract and a continuance option. This is the Base Program Interim Phase Topical Report presenting the results of Phase 1 of the CLVS research project. Test results and demonstration results provide a proof-of-concept for a system providing three-dimensional (3D) vision with the performance capability required to update geometric data on the order of once per second.

  9. Alignment validation

    SciTech Connect

    ALICE; ATLAS; CMS; LHCb; Golling, Tobias

    2008-09-06

    The four experiments, ALICE, ATLAS, CMS and LHCb are currently under constructionat CERN. They will study the products of proton-proton collisions at the Large Hadron Collider. All experiments are equipped with sophisticated tracking systems, unprecedented in size and complexity. Full exploitation of both the inner detector andthe muon system requires an accurate alignment of all detector elements. Alignmentinformation is deduced from dedicated hardware alignment systems and the reconstruction of charged particles. However, the system is degenerate which means the data is insufficient to constrain all alignment degrees of freedom, so the techniques are prone to converging on wrong geometries. This deficiency necessitates validation and monitoring of the alignment. An exhaustive discussion of means to validate is subject to this document, including examples and plans from all four LHC experiments, as well as other high energy experiments.

  10. Facilitating Constructive Alignment in Power Systems Engineering Education Using Free and Open-Source Software

    ERIC Educational Resources Information Center

    Vanfretti, L.; Milano, F.

    2012-01-01

    This paper describes how the use of free and open-source software (FOSS) can facilitate the application of constructive alignment theory in power systems engineering education by enabling the deep learning approach in power system analysis courses. With this aim, this paper describes the authors' approach in using the Power System Analysis Toolbox…

  11. The Role of System Alignment in Care and Education of Children from Birth to Grade 3

    ERIC Educational Resources Information Center

    Ma, Xin; Shen, Jianping; Krenn, Huilan Y.; Yuan, Jing; Hu, Shanshan

    2015-01-01

    The emerging concept of system alignment refers to how different systems in care and education of young children can be integrated to work together as a whole system that is more effective, efficient, and equitable to produce excellent outcomes in children. The purpose of this article is to provide a review of the existing literature on system…

  12. Evaluation of Eight Methods for Aligning Orientation of Two Coordinate Systems.

    PubMed

    Mecheri, Hakim; Robert-Lachaine, Xavier; Larue, Christian; Plamondon, André

    2016-08-01

    The aim of this study was to evaluate eight methods for aligning the orientation of two different local coordinate systems. Alignment is very important when combining two different systems of motion analysis. Two of the methods were developed specifically for biomechanical studies, and because there have been at least three decades of algorithm development in robotics, it was decided to include six methods from this field. To compare these methods, an Xsens sensor and two Optotrak clusters were attached to a Plexiglas plate. The first optical marker cluster was fixed on the sensor and 20 trials were recorded. The error of alignment was calculated for each trial, and the mean, the standard deviation, and the maximum values of this error over all trials were reported. One-way repeated measures analysis of variance revealed that the alignment error differed significantly across the eight methods. Post-hoc tests showed that the alignment error from the methods based on angular velocities was significantly lower than for the other methods. The method using angular velocities performed the best, with an average error of 0.17 ± 0.08 deg. We therefore recommend this method, which is easy to perform and provides accurate alignment. PMID:27245737

  13. GOPEX laser transmission and monitoring systems

    NASA Technical Reports Server (NTRS)

    Okamoto, G.; Masters, K.

    1993-01-01

    The laser transmission and monitoring system for the Galileo Optical Experiment (GOPEX) at the Table Mountain Facility (TMF) in Wrightwood, California is described. The transmission system configuration and the data measurement techniques are described. The calibration procedure and the data analysis algorithm are also discussed. The mean and standard deviation of the laser energy transmitted each day of GOPEX show that the laser transmission system performed well and within the limit established in conjunction with the Galileo Project for experiment concurrence.

  14. Stabilization system of a photoinjector drive laser.

    PubMed

    Le Flanchec, V; Blésès, J P; Striby, S; Laget, J P

    1997-11-20

    In the Etude d'un LaSer Accordable linear accelerator, electron bunches consist of trains of picosecond pulses extracted from a photocathode by a drive laser system. The fluctuations of the mean intensity of pulse trains at the output of the laser system are around 3% rms. A feed-forward stabilization system that reduces these fluctuations to better than 0.7% rms for periods of 5 min is presented. PMID:18264399

  15. Stabilization system of a photoinjector drive laser

    NASA Astrophysics Data System (ADS)

    Le Flanchec, Vincent; Blésès, Jean-Paul; Striby, Serge; Laget, Jean-Paul

    1997-11-01

    In the Etude d un LaSer Accordable linear accelerator, electron bunches consist of trains of picosecond pulses extracted from a photocathode by a drive laser system. The fluctuations of the mean intensity of pulse trains at the output of the laser system are around 3% rms. A feed-forward stabilization system that reduces these fluctuations to better than 0.7% rms for periods of 5 min is presented.

  16. Reducing beam shaper alignment complexity: diagnostic techniques for alignment and tuning

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd E.

    2011-10-01

    Safe and efficient optical alignment is a critical requirement for industrial laser systems used in a high volume manufacturing environment. Of specific interest is the development of techniques to align beam shaping optics within a beam line; having the ability to instantly verify by a qualitative means that each element is in its proper position as the beam shaper module is being aligned. There is a need to reduce these types of alignment techniques down to a level where even a newbie to optical alignment will be able to complete the task. Couple this alignment need with the fact that most laser system manufacturers ship their products worldwide and the introduction of a new set of variables including cultural and language barriers, makes this a top priority for manufacturers. Tools and methodologies for alignment of complex optical systems need to be able to cross these barriers to ensure the highest degree of up time and reduce the cost of maintenance on the production floor. Customers worldwide, who purchase production laser equipment, understand that the majority of costs to a manufacturing facility is spent on system maintenance and is typically the largest single controllable expenditure in a production plant. This desire to reduce costs is driving the trend these days towards predictive and proactive, not reactive maintenance of laser based optical beam delivery systems [10]. With proper diagnostic tools, laser system developers can develop proactive approaches to reduce system down time, safe guard operational performance and reduce premature or catastrophic optics failures. Obviously analytical data will provide quantifiable performance standards which are more precise than qualitative standards, but each have a role in determining overall optical system performance [10]. This paper will discuss the use of film and fluorescent mirror devices as diagnostic tools for beam shaper module alignment off line or in-situ. The paper will also provide an overview

  17. Optical tools and techniques for aligning solar payloads with the SPARCS control system. [Solar Pointing Aerobee Rocket Control System

    NASA Technical Reports Server (NTRS)

    Thomas, N. L.; Chisel, D. M.

    1976-01-01

    The success of a rocket-borne experiment depends not only on the pointing of the attitude control system, but on the alignment of the attitude control system to the payload. To ensure proper alignment, special optical tools and alignment techniques are required. Those that were used in the SPARCS program are described and discussed herein. These tools include theodolites, autocollimators, a 38-cm diameter solar simulator, a high-performance 1-m heliostat to provide a stable solar source during the integration of the rocket payload, a portable 75-cm sun tracker for use at the launch site, and an innovation called the Solar Alignment Prism. Using the real sun as the primary reference under field conditions, the Solar Alignment Prism facilitates the coalignment of the attitude sun sensor with the payload. The alignment techniques were developed to ensure the precise alignment of the solar payloads to the SPARCS attitude sensors during payload integration and to verify the required alignment under field conditions just prior to launch.

  18. Multiplex electric discharge gas laser system

    NASA Technical Reports Server (NTRS)

    Laudenslager, James B. (Inventor); Pacala, Thomas J. (Inventor)

    1987-01-01

    A multiple pulse electric discharge gas laser system is described in which a plurality of pulsed electric discharge gas lasers are supported in a common housing. Each laser is supplied with excitation pulses from a separate power supply. A controller, which may be a microprocessor, is connected to each power supply for controlling the application of excitation pulses to each laser so that the lasers can be fired simultaneously or in any desired sequence. The output light beams from the individual lasers may be combined or utilized independently, depending on the desired application. The individual lasers may include multiple pairs of discharge electrodes with a separate power supply connected across each electrode pair so that multiple light output beams can be generated from a single laser tube and combined or utilized separately.

  19. Alignment of the stellar spin with the orbits of a three-planet system.

    PubMed

    Sanchis-Ojeda, Roberto; Fabrycky, Daniel C; Winn, Joshua N; Barclay, Thomas; Clarke, Bruce D; Ford, Eric B; Fortney, Jonathan J; Geary, John C; Holman, Matthew J; Howard, Andrew W; Jenkins, Jon M; Koch, David; Lissauer, Jack J; Marcy, Geoffrey W; Mullally, Fergal; Ragozzine, Darin; Seader, Shawn E; Still, Martin; Thompson, Susan E

    2012-07-25

    The Sun's equator and the planets' orbital planes are nearly aligned, which is presumably a consequence of their formation from a single spinning gaseous disk. For exoplanetary systems this well-aligned configuration is not guaranteed: dynamical interactions may tilt planetary orbits, or stars may be misaligned with the protoplanetary disk through chaotic accretion , magnetic interactions or torques from neighbouring stars. Indeed, isolated 'hot Jupiters' are often misaligned and even orbiting retrograde. Here we report an analysis of transits of planets over starspots on the Sun-like star Kepler-30 (ref. 8), and show that the orbits of its three planets are aligned with the stellar equator. Furthermore, the orbits are aligned with one another to within a few degrees. This configuration is similar to that of our Solar System, and contrasts with the isolated hot Jupiters. The orderly alignment seen in the Kepler-30 system suggests that high obliquities are confined to systems that experienced disruptive dynamical interactions. Should this be corroborated by observations of other coplanar multi-planet systems, then star-disk misalignments would be ruled out as the explanation for the high obliquities of hot Jupiters, and dynamical interactions would be implicated as the origin of hot Jupiters.

  20. Alignment of the stellar spin with the orbits of a three-planet system.

    PubMed

    Sanchis-Ojeda, Roberto; Fabrycky, Daniel C; Winn, Joshua N; Barclay, Thomas; Clarke, Bruce D; Ford, Eric B; Fortney, Jonathan J; Geary, John C; Holman, Matthew J; Howard, Andrew W; Jenkins, Jon M; Koch, David; Lissauer, Jack J; Marcy, Geoffrey W; Mullally, Fergal; Ragozzine, Darin; Seader, Shawn E; Still, Martin; Thompson, Susan E

    2012-07-26

    The Sun's equator and the planets' orbital planes are nearly aligned, which is presumably a consequence of their formation from a single spinning gaseous disk. For exoplanetary systems this well-aligned configuration is not guaranteed: dynamical interactions may tilt planetary orbits, or stars may be misaligned with the protoplanetary disk through chaotic accretion , magnetic interactions or torques from neighbouring stars. Indeed, isolated 'hot Jupiters' are often misaligned and even orbiting retrograde. Here we report an analysis of transits of planets over starspots on the Sun-like star Kepler-30 (ref. 8), and show that the orbits of its three planets are aligned with the stellar equator. Furthermore, the orbits are aligned with one another to within a few degrees. This configuration is similar to that of our Solar System, and contrasts with the isolated hot Jupiters. The orderly alignment seen in the Kepler-30 system suggests that high obliquities are confined to systems that experienced disruptive dynamical interactions. Should this be corroborated by observations of other coplanar multi-planet systems, then star-disk misalignments would be ruled out as the explanation for the high obliquities of hot Jupiters, and dynamical interactions would be implicated as the origin of hot Jupiters. PMID:22836999

  1. Primary Mirror Figure Maintenance of the Hobby-Eberly Telescope using the Segment Alignment Maintenance System

    NASA Technical Reports Server (NTRS)

    Rakoczy, John; Hall, Drew; Howard, Ricky; Ly, William; Weir, John; Montgomery, Edward; Brantley, Lott W. (Technical Monitor)

    2002-01-01

    The Segment Alignment Maintenance System (SAMs) was installed on McDonald Observatory's Hobby-Eberly Telescope (HET) in August 2001. The SAMs became fully operational in October 2001. The SAMs uses a system of 480 inductive edge sensors to correct misalignments of the HET's 91 primary mirror segments when the segments are perturbed from their aligned reference positions. A special observer estimated and corrects for the global radius of curvature (GroC) mode, a mode unobservable by the edge sensors. The SAMs edge sensor system and (GroC) estimator are able to maintain HET's primary figure for much longer durations than previously had been observed. Telescope image quality has improved, and the amount of overhead time required from primary mirror alignment has been reduced. This paper gives a functional description of the SAMs control system and presents performance verification data. This paper also describes how the SAMs has improved the operational efficiency of the HET.

  2. The Geoscience Laser Altimetry/Ranging System

    NASA Technical Reports Server (NTRS)

    Cohen, Steven C.; Degnan, John J., III; Bufton, Jack L.; Garvin, James B.; Abshire, James B.

    1987-01-01

    The Geoscience Laser Altimetry/Ranging System (GLARS), a combined laser ranging and altimetry system capable of subcentimeter position determinations of retroflector targets and subdecimeter profiling of topography, is described. The system uses advanced but currently available state-of-the-art components. Laboratory, field, and numerical experiments have indicated the suitability of GLARS as an instrument for Eos and other space platforms.

  3. Laser beam modeling in optical storage systems

    NASA Technical Reports Server (NTRS)

    Treptau, J. P.; Milster, T. D.; Flagello, D. G.

    1991-01-01

    A computer model has been developed that simulates light propagating through an optical data storage system. A model of a laser beam that originates at a laser diode, propagates through an optical system, interacts with a optical disk, reflects back from the optical disk into the system, and propagates to data and servo detectors is discussed.

  4. Precision alignment and calibration of optical systems using computer generated holograms

    NASA Astrophysics Data System (ADS)

    Coyle, Laura Elizabeth

    As techniques for manufacturing and metrology advance, optical systems are being designed with more complexity than ever before. Given these prescriptions, alignment and calibration can be a limiting factor in their final performance. Computer generated holograms (CGHs) have several unique properties that make them powerful tools for meeting these demanding tolerances. This work will present three novel methods for alignment and calibration of optical systems using computer generated holograms. Alignment methods using CGHs require that the optical wavefront created by the CGH be related to a mechanical datum to locate it space. An overview of existing methods is provided as background, then two new alignment methods are discussed in detail. In the first method, the CGH contact Ball Alignment Tool (CBAT) is used to align a ball or sphere mounted retroreflector (SMR) to a Fresnel zone plate pattern with micron level accuracy. The ball is bonded directly onto the CGH substrate and provides permanent, accurate registration between the optical wavefront and a mechanical reference to locate the CGH in space. A prototype CBAT was built and used to align and bond an SMR to a CGH. In the second method, CGH references are used to align axi-symmetric optics in four degrees of freedom with low uncertainty and real time feedback. The CGHs create simultaneous 3D optical references where the zero order reflection sets tilt and the first diffracted order sets centration. The flexibility of the CGH design can be used to accommodate a wide variety of optical systems and maximize sensitivity to misalignments. A 2-CGH prototype system was aligned multiplied times and the alignment uncertainty was quantified and compared to an error model. Finally, an enhanced calibration method is presented. It uses multiple perturbed measurements of a master sphere to improve the calibration of CGH-based Fizeau interferometers ultimately measuring aspheric test surfaces. The improvement in the

  5. National Ignition Facility system design requirements Laser System SDR002

    SciTech Connect

    Larson, D.W.; Bowers, J.M.; Bliss, E.S.; Karpenko, V.P.; English, E.

    1996-08-20

    This System Design Requirement document establishes the performance, design, development, and test requirements for the NIP Laser System. The Laser System generates and delivers high-power optical pulses to the target chamber, and is composed of all optical puke creating and transport elements from Puke Generation through Final Optics as well as the special equipment that supports, energizes and controls them. The Laser System consists of the following WBS elements: 1.3 Laser System 1.4 Beam Transport System 1.6 Optical Components 1.7 Laser Control 1.8.7 Final Optics.

  6. Dynamically variable spot size laser system

    NASA Technical Reports Server (NTRS)

    Gradl, Paul R. (Inventor); Hurst, John F. (Inventor); Middleton, James R. (Inventor)

    2012-01-01

    A Dynamically Variable Spot Size (DVSS) laser system for bonding metal components includes an elongated housing containing a light entry aperture coupled to a laser beam transmission cable and a light exit aperture. A plurality of lenses contained within the housing focus a laser beam from the light entry aperture through the light exit aperture. The lenses may be dynamically adjusted to vary the spot size of the laser. A plurality of interoperable safety devices, including a manually depressible interlock switch, an internal proximity sensor, a remotely operated potentiometer, a remotely activated toggle and a power supply interlock, prevent activation of the laser and DVSS laser system if each safety device does not provide a closed circuit. The remotely operated potentiometer also provides continuous variability in laser energy output.

  7. Master-Oscillator/Power-Amplifier Laser System

    NASA Technical Reports Server (NTRS)

    Yu, Anthony W.; Krainak, Michael A.; Unger, Glenn L.

    1994-01-01

    Master-oscillator/power-amplifier (MOPA) laser system operates in continuous-wave mode or in amplitude-modulation (e.g., pulse) mode by modulation of oscillator current. Power amplifier is laser-diode-pumped neodymium:yttrium lithium fluoride (Nd:YLF) laser; oscillator is laser diode. Offers relatively high efficiency and power. Because drive current to oscillator modulated, external electro-optical modulator not needed. Potential uses include free-space optical communications, coded laser ranging, and generation of high-power, mode-locked pulses.

  8. Copper vapor laser acoustic thermometry system

    DOEpatents

    Galkowski, Joseph J.

    1987-01-01

    A copper vapor laser (CVL) acoustic thermometry system is disclosed. The invention couples an acoustic pulse a predetermined distance into a laser tube by means of a transducer and an alumina rod such that an echo pulse is returned along the alumina rod to the point of entry. The time differential between the point of entry of the acoustic pulse into the laser tube and the exit of the echo pulse is related to the temperature at the predetermined distance within the laser tube. This information is processed and can provide an accurate indication of the average temperature within the laser tube.

  9. Laser beam centering and pointing system

    DOEpatents

    Rushford, Michael Charles

    2015-01-13

    An optical instrument aligns an optical beam without the need for physical intervention of the instrument within the apparatus or platforms from which the trajectory of the beam to be ascertained. The alignment apparatus and method enable the desired function to be realized without the placement of physical apertures or sensors directly in the path of the beam through the system whose spatial position and slope is to be sought. An image plane provides the observer with a pair of well-defined images that are indicative of the beam centering and pointing alignment parameters. The optical alignment can be realized without the need for referencing to an external or fixed set of coordinates or fiducials. The instrument can therefore service situations where adverse environments would otherwise prohibit the use of such instruments, including regions of high radiation, high temperature, vacuum and/or cryogenic atmospheres.

  10. Calibration method for lumbosacral dimensions in wearable sensor system of lumbar alignment.

    PubMed

    Tsuchiya, Yoshio; Kusaka, Takashi; Tanaka, Takayuki; Matsuo, Yoshikazu; Oda, Makoto; Sasaki, Tsukasa; Kamishima, Tamotsu; Yamanaka, Masanori

    2015-01-01

    Anteflexion of the spine is essential for many physical activities in everyday life. However, this motion places the lumbar disks under heavy load due to changes in the shape of the lumbar spine and can lead to low back pain. With the aim of reducing low back pain, here we developed a wearable sensor system that can estimate lumbosacral alignment and lumbar load by measuring the shape of the lumbar skin when the lumbosacral alignment changes. In addition, we used this system to measure the parameters of anteflexion and studied the change in dimensions of the lumbar spine from changes in posture. By determining the dimensions of the lumbosacral spine on an X-ray image, a lumbosacral dimensions calibration method based on body surface area and height was developed. By using this method, lumbosacral alignment and lumbar load could be accurately estimated using the wearable sensor system.

  11. A Remotely Deployed Laser System for Viewing/Metrology

    SciTech Connect

    Barry, R.E.; Herndon, J.N.; Menon, M.M.; Spampinato, P.T.

    1999-04-25

    A metrology system is being developed for in-vessel inspection of present day experimental, and next generation fusion reactors. It requires accurate measuring capability to verify sub-millimeter alignment of plasma-facing components in the reactor vessel. A metrology system capable of achieving such accuracy for next generation reactors must be compatible with the vessel environment of high gamma radiation, high vacuum, elevated temperature, and magnetic field. This environment requires that the system must be remotely deployed. A coherent, frequency modulated laser radar system that is capable of correcting for environmental vibration meets these requirements. The metrologyhiewing system consists of a compact laser transceiver optics module which is linked through fiber optics to the laser source and imaging units, that are located outside of the harsh environment. The deployment mechanism configured for a next generation reactor was telescopic-mast positioning system. This paper identifies the requirements for the metrology/viewing system having precision ranging and surface mapping capability, and discusses the results of various environmental tests.

  12. A characterization of the LAP Aquarius Phantom for external LAP laser alignment and magnetic resonance geometric distortion verification for stereotactic radiation surgery patient simulation

    NASA Astrophysics Data System (ADS)

    Vergara, Daniel

    The Thesis explores additional applications of LAP's Aquarius external laser alignment verification Phantom by examining geometric accuracy of magnetic resonance images commonly used for planning intracranial stereotactic radiation surgery (ICSRS) cases. The scans were performed with MRI protocols used for ICSRS, and head and neck diagnosis, and their images fused to computerized tomographic (CT) images. The geometric distortions (GDs) were measured against the CT in all axial, sagittal, and coronal directions at different levels. Using the Aquarius Phantom, one is able to detect GD in ICSRS planning MRI acquisitions, and align the external LAP patient alignment lasers, by following the LAP QA protocol. GDs up to about 2 mm are observed at the distal regions of the longitudinal axis in the SRS treatment planning MR images. Based on the results, one may recommend the use of the Aquarius Phantom to determine if margins should be included for SRS treatment planning.

  13. The proposed alignment system for the Final Focus Test Beam at SLAC

    SciTech Connect

    Ruland, R.E.; Fischer, G.E.

    1990-09-01

    This report describes the current state of work in progress with respect to the geometry, alignment requirements, scenarios, and hardware for meeting the tolerances of the Final Focus Test Beam (FFTB) at SLAC. The methods and systems proposed acknowledge that component motion at the micron level, from whatever cause (ground motion, thermal effects, etc.) must be measured on-line and compensated for on relatively short time scales. To provide an integrated alignment/positioning package, some unique designs for reference systems, calibration of effect electric and magnetic centers, and component movers are introduced. 24 refs., 28 figs.

  14. Alignment of the Measurement Scale Mark during Immersion Hydrometer Calibration Using an Image Processing System

    PubMed Central

    Peña-Perez, Luis Manuel; Pedraza-Ortega, Jesus Carlos; Ramos-Arreguin, Juan Manuel; Arriaga, Saul Tovar; Fernandez, Marco Antonio Aceves; Becerra, Luis Omar; Hurtado, Efren Gorrostieta; Vargas-Soto, Jose Emilio

    2013-01-01

    The present work presents an improved method to align the measurement scale mark in an immersion hydrometer calibration system of CENAM, the National Metrology Institute (NMI) of Mexico, The proposed method uses a vision system to align the scale mark of the hydrometer to the surface of the liquid where it is immersed by implementing image processing algorithms. This approach reduces the variability in the apparent mass determination during the hydrostatic weighing in the calibration process, therefore decreasing the relative uncertainty of calibration. PMID:24284770

  15. Alignment of the measurement scale mark during immersion hydrometer calibration using an image processing system.

    PubMed

    Peña-Perez, Luis Manuel; Pedraza-Ortega, Jesus Carlos; Ramos-Arreguin, Juan Manuel; Arriaga, Saul Tovar; Fernandez, Marco Antonio Aceves; Becerra, Luis Omar; Hurtado, Efren Gorrostieta; Vargas-Soto, Jose Emilio

    2013-01-01

    The present work presents an improved method to align the measurement scale mark in an immersion hydrometer calibration system of CENAM, the National Metrology Institute (NMI) of Mexico, The proposed method uses a vision system to align the scale mark of the hydrometer to the surface of the liquid where it is immersed by implementing image processing algorithms. This approach reduces the variability in the apparent mass determination during the hydrostatic weighing in the calibration process, therefore decreasing the relative uncertainty of calibration. PMID:24284770

  16. WAVELENGTH AND ALIGNMENT TESTS FOR CONFOCAL SPECTRAL IMAGING SYSTEMS

    EPA Science Inventory

    Confocal spectral imaging (CSI) microscope systems now on the market delineate multiple fluorescent proteins, labels, or dyes within biological specimens by performing spectral characterizations. However, we find that some CSI present inconsistent spectral profiles of reference s...

  17. Laser Systems for Orbital Debris Removal

    SciTech Connect

    Rubenchik, A. M.; Barty, C. P. J.; Beach, R. J.; Erlandson, A. C.; Caird, J. A.

    2010-10-08

    The use of a ground based laser for space debris cleaning was investigated by the ORION project in 1996. Since that study the greatest technological advance in the development of high energy pulsed laser systems has taken place within the NIF project at LLNL. The proposed next laser system to follow the NIF at LLNL will be a high rep rate version of the NIF based on diode-pumping rather than flashlamp excitation; the so called 'LIFE' laser system. Because a single 'LIFE' beamline could be built up in a few year time frame, and has performance characteristics relevant to the space debris clearing problem, such a beamline could enable a near term demonstration of space debris cleaning. Moreover, the specifics of debris cleaning make it possible to simplify the LIFE laser beyond what is required for a fusion drive laser, and so substantially reduce its cost. Starting with the requirements for laser intensity on the target, and then considering beam delivery, we will flow back the laser requirements needed for space debris cleaning. Using these derived requirements we will then optimize the pulse duration, the operational regime, and the output pulse energy of the laser with a focus of simplifying its overall design. Anticipated simplifications include operation in the heat capacity regime, eliminating cooling requirements on the laser gain slabs, and relaxing B-integral and birefrigence requirements.

  18. Laser Systems for Orbital Debris Removal

    SciTech Connect

    Rubenchik, A M; Barty, C P; Beach, R J; Erlandson, A C; Caird, J A

    2010-02-05

    The use of a ground based laser for space debris cleaning was investigated by the ORION project in 1996. Since that study the greatest technological advance in the development of high energy pulsed laser systems has taken place within the NIF project at LLNL. The proposed next laser system to follow the NIF at LLNL will be a high rep rate version of the NIF based on diode-pumping rather than flashlamp excitation; the so called 'LIFE' laser system. Because a single 'LIFE' beamline could be built up in a few year time frame, and has performance characteristics relevant to the space debris clearing problem, such a beamline could enable a near term demonstration of space debris cleaning. Moreover, the specifics of debris cleaning make it possible to simplify the LIFE laser beyond what is required for a fusion drive laser, and so substantially reduce its cost. Starting with the requirements for laser intensity on the target, and then considering beam delivery, we will flow back the laser requirements needed for space debris cleaning. Using these derived requirements we will then optimize the pulse duration, the operational regime, and the output pulse energy of the laser with a focus of simplifying its overall design. Anticipated simplifications include operation in the heat capacity regime, eliminating cooling requirements on the laser gain slabs, and relaxing B-integral and birefrigence requirements.

  19. Laser Systems for Orbital Debris Removal

    NASA Astrophysics Data System (ADS)

    Rubenchik, A. M.; Barty, C. P. J.; Beach, R. J.; Erlandson, A. C.; Caird, J. A.

    2010-10-01

    The use of a ground based laser for space debris cleaning was investigated by the ORION project in 1996. Since that study the greatest technological advance in the development of high energy pulsed laser systems has taken place within the NIF project at LLNL. The proposed next laser system to follow the NIF at LLNL will be a high rep rate version of the NIF based on diode-pumping rather than flashlamp excitation; the so called "LIFE" laser system. Because a single "LIFE" beamline could be built up in a few year time frame, and has performance characteristics relevant to the space debris clearing problem, such a beamline could enable a near term demonstration of space debris cleaning. Moreover, the specifics of debris cleaning make it possible to simplify the LIFE laser beyond what is required for a fusion drive laser, and so substantially reduce its cost. Starting with the requirements for laser intensity on the target, and then considering beam delivery, we will flow back the laser requirements needed for space debris cleaning. Using these derived requirements we will then optimize the pulse duration, the operational regime, and the output pulse energy of the laser with a focus of simplifying its overall design. Anticipated simplifications include operation in the heat capacity regime, eliminating cooling requirements on the laser gain slabs, and relaxing B-integral and birefrigence requirements.

  20. Video Guidance Sensor System with Laser Rangefinder

    NASA Technical Reports Server (NTRS)

    Howard, Richard T. (Inventor); Johnston, Albert S. (Inventor); Book, Michael L. (Inventor); Bryan, Thomas C. (Inventor)

    2003-01-01

    A video guidance sensor system for use in automated docking of a chase vehicle with a target vehicle wherein the chase. vehicle includes a laser rangefinder that uses pulse or phase time of flight measurement to measure distance. The laser rangefinder includes a diode laser pulse or phase driver that produces an output signal to a timing element and simultaneously operates a laser diode. The laser diode produces an intense light beam of a predetermined wavelength which is directed to retroreflectors that are positioned on a passive target. The laser rangefinder includes an avalanche photodetector that produces a corresponding output signal when detecting light reflected from the retroreflectors. The timing element measures a time interval between the output of the laser diode and the detection of light and supplies a corresponding output signal to a computer in order to determine the range of the target vehicle relative to the chase vehicle.

  1. [Design of an integrative laser laryngoscope system].

    PubMed

    Zhang, Yangde; Qiao, Jingliang

    2012-10-01

    Laser technology is widely used in many medical fields such as general surgery, cardio-thoracic surgery, neurosurgery and urology. Laser has the characteristics of identical direction and high energy density, so that a laser knife leaves smooth incisions, less hemorrhage and less infection. The design presented in this paper applied the advanced laser technology in laryngoscopic operations, which increases efficiency and safety of the operation. The design included a laryngoscope, a laser-knife system host machine and a laser-knife, which were integrated in the front of the laryngoscope working terminal. Operators could choose the laser with appropriate wavelength to cut, irradiate, stop bleeding and coagulate the foreign objects or lesions of the larynx. A Chinese national patent (patent number ZL201020537693. 5) has been granted to the design.

  2. Microprocessor-Controlled Laser Balancing System

    NASA Technical Reports Server (NTRS)

    Demuth, R. S.

    1985-01-01

    Material removed by laser action as part tested for balance. Directed by microprocessor, laser fires appropriate amount of pulses in correct locations to remove necessary amount of material. Operator and microprocessor software interact through video screen and keypad; no programing skills or unprompted system-control decisions required. System provides complete and accurate balancing in single load-and-spinup cycle.

  3. Personal medical information system using laser card

    NASA Astrophysics Data System (ADS)

    Cho, Seong H.; Kim, Keun Ho; Choi, Hyung-Sik; Park, Hyun Wook

    1996-04-01

    The well-known hospital information system (HIS) and the picture archiving and communication system (PACS) are typical applications of multimedia to medical area. This paper proposes a personal medical information save-and-carry system using a laser card. This laser card is very useful, especially in emergency situations, because the medical information in the laser card can be read at anytime and anywhere if there exists a laser card reader/writer. The contents of the laser card include the clinical histories of a patient such as clinical chart, exam result, diagnostic reports, images, and so on. The purpose of this system is not a primary diagnosis, but emergency reference of clinical history of the patient. This personal medical information system consists of a personal computer integrated with laser card reader/writer, color frame grabber, color CCD camera and a high resolution image scanner optionally. Window-based graphical user interface was designed for easy use. The laser card has relatively sufficient capacity to store the personal medical information, and has fast access speed to restore and load the data with a portable size as compact as a credit card. Database items of laser card provide the doctors with medical data such as laser card information, patient information, clinical information, and diagnostic result information.

  4. Integration and alignment of ATLAS instrument engineering model components in Optical Development System Lab

    NASA Astrophysics Data System (ADS)

    Evans, Tyler

    2013-09-01

    The ATLAS Instrument for the ICESat-2 mission at NASA's Goddard Space Flight Center required a test-bed to prove out new concepts before the mission launches in 2016. The Optical Development System (ODS) laboratory was created to use breadboard, prototype, and engineering-model levels of hardware and software to model and evaluate the ATLAS alignment system. A one meter parabolic mirror was used to create a collimated light beam to align prototype and engineering model transmitter and receiver optics and test closed-loop alignment algorithms. To achieve an error of less than two micro-radians, an active deformable mirror was used to correct the wave front to subtract out the collimator mount error.

  5. Alignment solutions for the optical development system lab for the ATLAS instrument

    NASA Astrophysics Data System (ADS)

    Evans, Tyler; Lehan, John; Chavez, Hector

    2012-10-01

    The ATLAS Instrument for the ICESat-2 mission at NASA's Goddard Space Flight Center requires a test-bed to prove out new concepts before the mission launches in 2016. The Optical Development System (ODS) laboratory was created to use breadboard, prototype, and engineering-model levels of hardware and software to model and evaluate the ATLAS alignment system. A one meter parabolic mirror was used to create a collimated light beam to align prototype and engineering model transmitter and receiver optics and test closed-loop alignment algorithms. To achieve an error of less than two micro-radians, an active deformable mirror was used to correct the wave front to subtract out the collimator mount error.

  6. Alignment dependence in the breakup of the H2 molecule by xuv laser pulses

    NASA Astrophysics Data System (ADS)

    Guan, Xiaoxu; Bartschat, Klaus; Schneider, Barry I.

    2011-05-01

    We present predictions of angular distributions for two-photon double ionization of the hydrogen molecule by a short laser pulse with a central photon energy of 30 eV. Using the fixed-nuclei approximation, the laser-driven electronic wave packets are obtained by solving the time-dependent Schrödinger equation in two-center elliptical coordinates with the internuclear distance fixed at 1.4 bohr. In addition to the parallel and perpendicular geometries, we explore the dependence of the angular distribution on the relative orientation of the molecular axis and the linear polarization vector of the laser field. The individual contributions from the 1Σg and 1Δg channels are found to be very sensitive to both the orientation angle and the direction of the reference electron that is observed at a fixed angle with a preset energy. The resulting interference effect between the different ionization channels is analyzed in detail. Work supported by the NSF under PHY-0903818 and PHY-0757755. Supercomputer resources provided through the NSF TeraGrid allocation award TG-PHY090031 and by the Department of Energy allocation award MPH006.

  7. Distributed computer control system in the Nova Laser Fusion Test Facility

    SciTech Connect

    Not Available

    1985-09-01

    The EE Technical Review has two purposes - to inform readers of various activities within the Electronics Engineering Department and to promote the exchange of ideas. The articles, by design, are brief summaries of EE work. The articles included in this report are as follows: Overview - Nova Control System; Centralized Computer-Based Controls for the Nova Laser Facility; Nova Pulse-Power Control System; Nova Laser Alignment Control System; Nova Beam Diagnostic System; Nova Target-Diagnostics Control System; and Nova Shot Scheduler. The 7 papers are individually abstracted.

  8. Laser Surveillance System for Spent Fuel

    SciTech Connect

    Fiarman, S.; Zucker, M. S.; Bieber, Jr., A. M.

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools (SFSP's) will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a full size laser system operating in air and have used an array of 6 zircaloy BWR tubes to simulate an assembly. The reflective signal from the zircaloy rods is a strong function of position of the assembly, but in all cases is easily discernable from the reference scan of the background with no assembly. A design for a SFSP laser surveillance system incorporating laser ranging is discussed. 10 figures.

  9. The Theory of Random Laser Systems

    SciTech Connect

    Xunya Jiang

    2002-06-27

    Studies of random laser systems are a new direction with promising potential applications and theoretical interest. The research is based on the theories of localization and laser physics. So far, the research shows that there are random lasing modes inside the systems which is quite different from the common laser systems. From the properties of the random lasing modes, they can understand the phenomena observed in the experiments, such as multi-peak and anisotropic spectrum, lasing mode number saturation, mode competition and dynamic processes, etc. To summarize, this dissertation has contributed the following in the study of random laser systems: (1) by comparing the Lamb theory with the Letokhov theory, the general formulas of the threshold length or gain of random laser systems were obtained; (2) they pointed out the vital weakness of previous time-independent methods in random laser research; (3) a new model which includes the FDTD method and the semi-classical laser theory. The solutions of this model provided an explanation of the experimental results of multi-peak and anisotropic emission spectra, predicted the saturation of lasing modes number and the length of localized lasing modes; (4) theoretical (Lamb theory) and numerical (FDTD and transfer-matrix calculation) studies of the origin of localized lasing modes in the random laser systems; and (5) proposal of using random lasing modes as a new path to study wave localization in random systems and prediction of the lasing threshold discontinuity at mobility edge.

  10. Magnetic prism alignment system for measuring large-angle strabismus.

    PubMed

    Bishop, John Edward

    2014-02-01

    Prismatic measurement of large-angle strabismus requires the simultaneous use of two or more prisms for neutralization. To facilitate the clinical measurement of large-angle strabismus a new prism system was designed utilizing a flat plate and a ferrous metal surface coupled with prisms containing rare earth magnets implanted in their base and bottom surfaces. PMID:24569000

  11. Magnetic prism alignment system for measuring large-angle strabismus.

    PubMed

    Bishop, John Edward

    2014-02-01

    Prismatic measurement of large-angle strabismus requires the simultaneous use of two or more prisms for neutralization. To facilitate the clinical measurement of large-angle strabismus a new prism system was designed utilizing a flat plate and a ferrous metal surface coupled with prisms containing rare earth magnets implanted in their base and bottom surfaces.

  12. Development of a high magnetic field assisted pulsed laser deposition system.

    PubMed

    Zhang, Kejun; Dai, Jianming; Wu, Wenbin; Zhang, Peng; Zuo, Xuzhong; Zhou, Shu; Zhu, Xuebin; Sheng, Zhigao; Liang, Changhao; Sun, Yuping

    2015-09-01

    A high magnetic field assisted pulsed laser deposition (HMF-PLD) system has been developed to in situ grow thin films in a high magnetic field up to 10 T. In this system, a specially designed PLD cylindrical vacuum chamber is horizontally located in the bore configuration of a superconducting magnet with a bore diameter of 200 mm. To adjust the focused pulsed laser into the target in such a narrow PLD vacuum chamber, an ingeniously built-in laser leading-in chamber is employed, including a laser mirror with a reflection angle of 65° and a damage threshold up to 3.4 J/cm(2). A laser alignment system consisting of a built-in video-unit leading-in chamber and a low-energy alignment laser is applied to monitor and align the pulsed laser propagation in the PLD vacuum chamber. We have grown La0.7Sr0.3MnO3 (LSMO) thin films on (LaAlO3)0.3(Sr2AlTaO6)0.7 (001) [LSAT (001)] substrates by HMF-PLD. The results show that the nanostructures of the LSMO films can be tuned from an epitaxially continuous film structure without field to a vertically aligned nanorod structure with an applied high magnetic field above 5 T, and the dimension size of the nanorods can be tuned by the strength of the magnetic field. The associated magnetic anisotropy is found to be highly dependent on the nanorod structures. We show how the HMF-PLD provides an effective route toward tuning the nanostructures and the physical properties of functional thin films, giving it an important role in development of nanodevices and their application. PMID:26429478

  13. Test performance of the PARSEC laser system

    NASA Astrophysics Data System (ADS)

    Rabien, Sebastian; Davies, Richard I.; Ott, Thomas; Li, Jianlang; Abuter, Roberto; Kellner, Stefan; Neumann, Udo

    2004-10-01

    The PARSEC laser system is designed for the VLT Laser Guide Star Facility to deliver a high power cw laser beam at 589nm, in order to create an artificial guide star in the mesospheric Sodium layer. The laser consists of a resonant, dye based power amplifier which is injection seeded with 589nm, single frequency radiation from a master oscillator. We report on the performance of the system both during the European Acceptance tests, and that which has been achieved in the laboratory. The maximum power we have obtained amounts to 20W cw laser light in a single mode and a single frequency at 589nm. With a beam quality of M2 of 1.05-1.15 and a long term stability without manual intervention, the laser suits all the demands for operation at the VLT.

  14. A line-source method for aligning on-board and other pinhole SPECT systems

    PubMed Central

    Yan, Susu; Bowsher, James; Yin, Fang-Fang

    2013-01-01

    Purpose: In order to achieve functional and molecular imaging as patients are in position for radiation therapy, a robotic multipinhole SPECT system is being developed. Alignment of the SPECT system—to the linear accelerator (LINAC) coordinate frame and to the coordinate frames of other on-board imaging systems such as cone-beam CT (CBCT)—is essential for target localization and image reconstruction. An alignment method that utilizes line sources and one pinhole projection is proposed and investigated to achieve this goal. Potentially, this method could also be applied to the calibration of the other pinhole SPECT systems. Methods: An alignment model consisting of multiple alignment parameters was developed which maps line sources in three-dimensional (3D) space to their two-dimensional (2D) projections on the SPECT detector. In a computer-simulation study, 3D coordinates of line-sources were defined in a reference room coordinate frame, such as the LINAC coordinate frame. Corresponding 2D line-source projections were generated by computer simulation that included SPECT blurring and noise effects. The Radon transform was utilized to detect angles (α) and offsets (ρ) of the line-source projections. Alignment parameters were then estimated by a nonlinear least squares method, based on the α and ρ values and the alignment model. Alignment performance was evaluated as a function of number of line sources, Radon transform accuracy, finite line-source width, intrinsic camera resolution, Poisson noise, and acquisition geometry. Experimental evaluations were performed using a physical line-source phantom and a pinhole-collimated gamma camera attached to a robot. Results: In computer-simulation studies, when there was no error in determining angles (α) and offsets (ρ) of the measured projections, six alignment parameters (three translational and three rotational) were estimated perfectly using three line sources. When angles (α) and offsets (ρ) were provided by

  15. A line-source method for aligning on-board and other pinhole SPECT systems

    SciTech Connect

    Yan, Susu; Bowsher, James; Yin, Fang-Fang

    2013-12-15

    Purpose: In order to achieve functional and molecular imaging as patients are in position for radiation therapy, a robotic multipinhole SPECT system is being developed. Alignment of the SPECT system—to the linear accelerator (LINAC) coordinate frame and to the coordinate frames of other on-board imaging systems such as cone-beam CT (CBCT)—is essential for target localization and image reconstruction. An alignment method that utilizes line sources and one pinhole projection is proposed and investigated to achieve this goal. Potentially, this method could also be applied to the calibration of the other pinhole SPECT systems.Methods: An alignment model consisting of multiple alignment parameters was developed which maps line sources in three-dimensional (3D) space to their two-dimensional (2D) projections on the SPECT detector. In a computer-simulation study, 3D coordinates of line-sources were defined in a reference room coordinate frame, such as the LINAC coordinate frame. Corresponding 2D line-source projections were generated by computer simulation that included SPECT blurring and noise effects. The Radon transform was utilized to detect angles (α) and offsets (ρ) of the line-source projections. Alignment parameters were then estimated by a nonlinear least squares method, based on the α and ρ values and the alignment model. Alignment performance was evaluated as a function of number of line sources, Radon transform accuracy, finite line-source width, intrinsic camera resolution, Poisson noise, and acquisition geometry. Experimental evaluations were performed using a physical line-source phantom and a pinhole-collimated gamma camera attached to a robot.Results: In computer-simulation studies, when there was no error in determining angles (α) and offsets (ρ) of the measured projections, six alignment parameters (three translational and three rotational) were estimated perfectly using three line sources. When angles (α) and offsets (ρ) were provided by

  16. Constructing a Low-budget Laser Axotomy System to Study Axon Regeneration in C. elegans

    PubMed Central

    Williams, Wes; Nix, Paola; Bastiani, Michael

    2011-01-01

    Laser axotomy followed by time-lapse microscopy is a sensitive assay for axon regeneration phenotypes in C. elegans1. The main difficulty of this assay is the perceived cost ($25-100K) and technical expertise required for implementing a laser ablation system2,3. However, solid-state pulse lasers of modest costs (<$10K) can provide robust performance for laser ablation in transparent preparations where target axons are "close" to the tissue surface. Construction and alignment of a system can be accomplished in a day. The optical path provided by light from the focused condenser to the ablation laser provides a convenient alignment guide. An intermediate module with all optics removed can be dedicated to the ablation laser and assures that no optical elements need be moved during a laser ablation session. A dichroic in the intermediate module allows simultaneous imaging and laser ablation. Centering the laser beam to the outgoing beam from the focused microscope condenser lens guides the initial alignment of the system. A variety of lenses are used to condition and expand the laser beam to fill the back aperture of the chosen objective lens. Final alignment and testing is performed with a front surface mirrored glass slide target. Laser power is adjusted to give a minimum size ablation spot (<1um). The ablation spot is centered with fine adjustments of the last kinematically mounted mirror to cross hairs fixed in the imaging window. Laser power for axotomy will be approximately 10X higher than needed for the minimum ablation spot on the target slide (this may vary with the target you use). Worms can be immobilized for laser axotomy and time-lapse imaging by mounting on agarose pads (or in microfluidic chambers4). Agarose pads are easily made with 10% agarose in balanced saline melted in a microwave. A drop of molten agarose is placed on a glass slide and flattened with another glass slide into a pad approximately 200 um thick (a single layer of time tape on adjacent

  17. 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.

  18. Pi topology and spin alignment in unique photoexcited triplet and quintet states arising from four unpaired electrons of an organic spin system.

    PubMed

    Teki, Yoshio; Toichi, Tetuya; Nakajima, Satoru

    2006-03-01

    Syntheses, electronic structures in the ground state, unique photoexcited states, and spin alignment are reported for novel biradical 1, which was designed as an ideal model compound to investigate photoinduced spin alignment in the excited state. Electron spin resonance (ESR), time-resolved ESR (TRESR), and laser-excitation pulsed ESR experiments were carried out. The magnetic properties were examined with a SQUID magnetometer. In the electronic ground state, two radical moieties interact very weakly (almost no interaction) with each other through the closed-shell diphenylanthracene spin coupler. On photoirradiation, a novel lowest photoexcited state with the intermediate spin (S = 1) arising from four unpaired electrons with low-lying quintet (S = 2) photoexcited state was detected. The unique triplet state has an interesting electronic structure, the D value of which is reduced by antiferromagnetic spin alignment between two radical spins through the excited triplet spin coupler. The general theoretical predictions of the spin alignment and the reduction of the fine-structure splitting of the triplet bis(radical) systems are presented. The fine-structure splitting of the unique photoexcited triplet state of 1, as well as the existence of the low-lying quintet state, is interpreted well on the basis of theoretical predictions. Details of the spin alignment in the photoexcited states are discussed. PMID:16372362

  19. The development and progress of XeCl Excimer laser system

    NASA Astrophysics Data System (ADS)

    Zhang, Yongsheng; Ma, Lianying; Wang, Dahui; Zhao, Xueqing; Zhu, Yongxiang; Hu, Yun; Qian, Hang; Shao, Bibo; Yi, Aiping; Liu, Jingru

    2015-05-01

    A large angularly multiplexed XeCl Excimer laser system is under development at the Northwest Institute of Nuclear Technology (NINT). It is designed to explore the technical issues of uniform and controllable target illumination. Short wavelength, uniform and controllable target illumination is the fundamental requirement of high energy density physics research using large laser facility. With broadband, extended light source and multi-beam overlapping techniques, rare gas halide Excimer laser facility will provide uniform target illumination theoretically. Angular multiplexing and image relay techniques are briefly reviewed and some of the limitations are examined to put it more practical. The system consists of a commercial oscillator front end, three gas discharge amplifiers, two electron beam pumped amplifiers and the optics required to relay, encode and decode the laser beam. An 18 lens array targeting optics direct and focus the laser in the vacuum target chamber. The system is operational and currently undergoing tests. The total 18 beams output energy is more than 100J and the pulse width is 7ns (FWHM), the intensities on the target will exceed 1013W/cm2. The aberration of off-axis imaging optics at main amplifier should be minimized to improve the final image quality at the target. Automatic computer controlled alignment of the whole system is vital to efficiency and stability of the laser system, an array of automatic alignment model is under test and will be incorporated in the system soon.

  20. Laser pointing determination for the geoscience laser altimeter system

    NASA Technical Reports Server (NTRS)

    Miller, Pamela S.; Sirota, J. Marcos

    1998-01-01

    The Geoscience Laser Altimeter System (GLAS) is a space-based lidar being developed to monitor changes in the mass balance of the Earth's polar ice sheets (Thomas et al. 1985). GLAS is part of NASA's Earth Observing System (Schutz 1995), and is being designed to launch into a 600 km circular polar orbit in the year 2001, for continuous operation over 3 to 5 years. The orbit's 94 degree inclination has been selected to allow good coverage and profile patterns over the ice sheets of Greenland and Antarctica. The GLAS mission uses a small dedicated spacecraft provided by Ball Aerospace, which is required to have a very stable nadir and zenith pointing platform which points to within approximately 100 urad (20 arcseconds) of Nadir. Accurate knowledge of the laser beam's pointing angle (in the far field) is critical since pointing the laser beam away from nadir biases the altimetry measurements (Gardner 1992, Bufton et al. 1991). This error is a function of the distance of the laser centroid off nadir multiplied by the orbit altitude and the tangent of the slope angle of the terrain. Most of the ice sheet surface slopes are less than 1? resulting in pointing knowledge bias of only 7.6 cm with 7.3 urad accuracy, and overall single shot height accuracy of approximately 15 cm. However, over a 3 deg surface slope pointing knowledge to approximately 7.3 urad is the largest error source (23 cm) in achieving 26 cm height accuracy. The GLAS design incorporates a stellar reference system (SRS) to relate the laser beam pointing angle to the star field to an accuracy of 7.3 urad. The stellar reference system combines an attitude determination system (ADS) operating from 4 to 10 Hz coupled to a 40 Hz laser reference system (LRS) to perform this task.

  1. Alignment in Complex Education Systems: Achieving Balance and Coherence. OECD Education Working Papers, Number 64

    ERIC Educational Resources Information Center

    Looney, Janet W.

    2011-01-01

    The majority of OECD countries now implement one form or another of standards-based assessment and evaluation. The core logic of standards-based systems rests upon the alignment of three key elements: "standards" defining the knowledge and skills--or "competences"--students are expected to have attained at different stages of their education;…

  2. Performance Reports: Mirror alignment system performance prediction comparison between SAO and EKC

    NASA Technical Reports Server (NTRS)

    Tananbaum, H. D.; Zhang, J. P.

    1994-01-01

    The objective of this study is to perform an independent analysis of the residual high resolution mirror assembly (HRMA) mirror distortions caused by force and moment errors in the mirror alignment system (MAS) to statistically predict the HRMA performance. These performance predictions are then compared with those performed by Kodak to verify their analysis results.

  3. Terminator field-aligned current system: Its dependencies on solar, seasonal, and geomagnetic conditions

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Schunk, R. W.; Eccles, V.; Scherliess, L.; Sojka, J. J.; Gardner, L. C.

    2015-12-01

    A new field-aligned current system in the high-latitude ionosphere was reported recently by Zhu et al. (2014). The current system develops and evolves along the ionospheric terminator and it is thus termed as the terminator field-aligned currents. The discovery was based on the reconstructions from the Ionospheric Dynamics and Electrodynamics Data Assimilation Model (IDED-DA) with the ingestion of observational measurements. In this presentation, we show the results of a follow-on study using the IDED-DA, in which the solar, seasonal, and geomagnetic dependencies of the terminator field-aligned currents are explored. The new current system is the first field-aligned current system in the high-latitude ionosphere that is not directly driven by the magnetospheric dynamics and has an ionospheric origin. A systematic study of its electrodynamic and plasma dynamics as well as dependencies on various solar-terrestrial conditions will help us to explore the active role of the ionosphere in the magnetosphere-ionosphere coupling and improve the physical understanding of the electrodynamics and plasma dynamics of many small-scale structures in the polar ionosphere.

  4. An Improved Alignment Method for the Strapdown Inertial Navigation System (SINS).

    PubMed

    Liu, Meng; Gao, Yanbin; Li, Guangchun; Guang, Xingxing; Li, Shutong

    2016-01-01

    In this paper, an innovative inertial navigation system (INS) mechanization and the associated Kalman filter (KF) are developed to implement a fine alignment for the strapdown INS (SINS) on stationary base. The improved mechanization is established in the pseudo-geographic frame, which is rebuilt based on the initial position. The new mechanization eliminates the effects of linear movement errors on the heading by decoupling. Compared with the traditional local-level mechanization, it has more advantages. The proposed algorithm requires lower coarse alignment accuracy in both the open-loop and closed-loop KFs and hence can improve the system reliability and decrease the total alignment time. Moreover, for the closed-loop KF, it can decrease oscillation caused by the system errors and improve the closed-loop system stability. In addition, the proposed algorithm can also be applied to polar alignment. The performance of the proposed algorithm is verified by both simulations and experiments and the results exhibit the superior performance of the proposed approach. PMID:27136565

  5. An Improved Alignment Method for the Strapdown Inertial Navigation System (SINS)

    PubMed Central

    Liu, Meng; Gao, Yanbin; Li, Guangchun; Guang, Xingxing; Li, Shutong

    2016-01-01

    In this paper, an innovative inertial navigation system (INS) mechanization and the associated Kalman filter (KF) are developed to implement a fine alignment for the strapdown INS (SINS) on stationary base. The improved mechanization is established in the pseudo-geographic frame, which is rebuilt based on the initial position. The new mechanization eliminates the effects of linear movement errors on the heading by decoupling. Compared with the traditional local-level mechanization, it has more advantages. The proposed algorithm requires lower coarse alignment accuracy in both the open-loop and closed-loop KFs and hence can improve the system reliability and decrease the total alignment time. Moreover, for the closed-loop KF, it can decrease oscillation caused by the system errors and improve the closed-loop system stability. In addition, the proposed algorithm can also be applied to polar alignment. The performance of the proposed algorithm is verified by both simulations and experiments and the results exhibit the superior performance of the proposed approach. PMID:27136565

  6. Tip alignment system in a sextupole-corrected scanning transmission electron microscope

    NASA Astrophysics Data System (ADS)

    Ruan, Shengyang; Kapp, Oscar H.

    1993-03-01

    Tip alignment and replacement in ultrahigh vacuum field-emission electron microscopes is traditionally a time-consuming endeavor. A convenient autodrive system for the 200 kV scanning transmission electron microscope was developed to facilitate the alignment of field-emission tips, thus saving a great deal of experimenter time. Under computer control, a series of automatic electrical and mechanical processes are initiated to systematically adjust various parameters to effect passage of the electron beam through the various apertures of the microscope column. The task of ``finding the beam'' is thus performed automatically. In this process the tip holder is moved in a raster parallel to the first anode. Feedback from various detectors placed throughout the column direct the positioning of the tip for optimal alignment. This process is routinely performed in about 45 min.

  7. Laser-induced periodic alignment of Ag nanoparticles in soda-lime glass.

    PubMed

    Goutaland, François; Colombier, Jean-Philippe; Sow, Mohamed Cherif; Ollier, Nadège; Vocanson, Francis

    2013-12-30

    One-, two- or three-dimensional arrays of closely spaced silver nanoparticles may lead to new optical properties, due to short or long range coupling between their resonant surface plasmons, so that the spatially controlled growth of silver nanoparticles provides an efficient way to tune their optical properties. Towards this way, we present here the periodic pattern of a glass surface with silver nanoparticles by continuous ultraviolet laser exposure. The formation of the 160 nm period pattern is well described by an interference-based model which agrees with the experimental conclusions, mainly obtained by various forms of microscopy. Statistical approach based on the autocorrelation function gives quantitative description about the quality of the order in the periodic structure and about the nanoparticles averaged diameter (80 nm). We also present the optical extinction spectrum of the Laser Induced Periodic Surface Structure (LIPSS)-containing area of the glass, which unusually shows several bands in the visible range. The period of 160 nm of the periodic structure is short enough to allow coupling between nanoparticles, which makes it a possible candidate for plasmon-based optical applications.

  8. First Results of the LCLS Laser-Heater System

    SciTech Connect

    Emma, P; Boyce, R.F.; Brachmann, A.; Carr, R.; Decker, F.-J.; Ding, Y.; Dowell, D.; Edstrom, S.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, Ph.; Huang, Z.; Iverson, R.; Levashov, Y.; Loos, H.; Miahnahri, A.; Nuhn, H.-D.; Poling, B.; Ratner, D.; Spampinati, S.; /SLAC

    2011-12-16

    The Linac Coherent Light Source (LCLS) is an x-ray Free-Electron Laser (FEL) project that has just achieved its first lasing at 1.5 {angstrom} radiation wavelength. The very bright electron beam required to drive this FEL is susceptible to a microbunching instability in the magnetic bunch compressors that may increase the slice energy spread beyond the FEL tolerance. To control the slice energy spread and to suppress the microbunching instability, a laser heater (LH) system is installed in the LCLS injector area at 135 MeV, right before the RF deflector that is used for the time-resolved electron diagnostics. This unique component is used to add a small level of intrinsic energy spread to the electron beam in order to Landau damp the microbunching instability before it potentially breaks up the high brightness electron beam. The system was fully installed and tested in the fall of 2008, and effects of heating on the electron beam and the x-ray FEL were studied during the 2009 commissioning period. The laser heater system is composed of a 4-dipole chicane; a 9-period, planar, permanent-magnet, adjustable-gap undulator at the center of the chicane; one OTR screen on each side of the undulator for electron/laser spatial alignment; and an IR laser (up to 15-MW power) which co-propagates with the electron beam inside the undulator generating a 758-nm energy modulation along the bunch. The final two dipoles of the 4-dipole chicane time-smear this modulation leaving only a thermal-like intrinsic energy spread within the bunch. Table 1 lists the main parameters for this system. The very bright electron beam required for an x-ray free-electron laser (FEL), such as the LCLS, is susceptible to a microbunching instability in the magnetic bunch compressors, prior to the FEL undulator. The uncorrelated electron energy spread in the LCLS can be increased by an order of magnitude to provide strong Landau damping against the instability without degrading the FEL performance. To

  9. Active polarimeter optical system laser hazard analysis.

    SciTech Connect

    Augustoni, Arnold L.

    2005-07-01

    A laser hazard analysis was performed for the SNL Active Polarimeter Optical System based on the ANSI Standard Z136.1-2000, American National Standard for Safe Use of Lasers and the ANSI Standard Z136.6-2000, American National Standard for Safe Use of Lasers Outdoors. The Active Polarimeter Optical System (APOS) uses a pulsed, near-infrared, chromium doped lithium strontium aluminum fluoride (Cr:LiSAF) crystal laser in conjunction with a holographic diffuser and lens to illuminate a scene of interest. The APOS is intended for outdoor operations. The system is mounted on a height adjustable platform (6 feet to 40 feet) and sits atop a tripod that points the beam downward. The beam can be pointed from nadir to as much as 60 degrees off of nadir producing an illuminating spot geometry that can vary from circular (at nadir) to elliptical in shape (off of nadir). The JP Innovations crystal Cr:LiSAF laser parameters are presented in section II. The illuminating laser spot size is variable and can be adjusted by adjusting the separation distance between the lens and the holographic diffuser. The system is adjusted while platform is at the lowest level. The laser spot is adjusted for a particular spot size at a particular distance (elevation) from the laser by adjusting the separation distance (d{sub diffuser}) to predetermined values. The downward pointing angle is also adjusted before the platform is raised to the selected operation elevation.

  10. Resonators for solid-state lasers with large-volume fundamental mode and high alignment stability

    SciTech Connect

    Magni, V.

    1986-01-01

    Resonators containing a focusing rod are thoroughly analyzed. It is shown that, as a function of the dioptric power of the rod, two stability zones of the same width exist and that the mode volume in the rod always presents a stationary point. At this point, the output power is insensitive to the focal length fluctuations, and the mode volume inside the rod is inversely proportional to the range of the input power for which the resonator is stable. The two zones are markedly different with respect to misalignment sensitivity, which is, in general, much greater in one zone than in the other. Two design procedures are presented for monomode solid-state laser resonators with large mode volume and low sensitivity both to focal length fluctuations and to misalignment.

  11. THE BANANA PROJECT. IV. TWO ALIGNED STELLAR ROTATION AXES IN THE YOUNG ECCENTRIC BINARY SYSTEM EP CRUCIS: PRIMORDIAL ORIENTATION AND TIDAL ALIGNMENT

    SciTech Connect

    Albrecht, Simon; Winn, Joshua N.; Setiawan, Johny; Torres, Guillermo; Fabrycky, Daniel C.

    2013-04-10

    With observations of the EP Cru system, we continue our series of measurements of spin-orbit angles in eclipsing binary star systems, the BANANA project (Binaries Are Not Always Neatly Aligned). We find a close alignment between the sky projections of the rotational and orbital angular momentum vectors for both stars ({beta}{sub p} = -1. Degree-Sign 8 {+-} 1. Degree-Sign 6 and |{beta}{sub s}| < 17 Degree-Sign ). We also derive precise absolute dimensions and stellar ages for this system. The EP Cru and DI Her systems provide an interesting comparison: they have similar stellar types and orbital properties, but DI Her is younger and has major spin-orbit misalignments, raising the question of whether EP Cru also had a large misalignment at an earlier phase of evolution. We show that tidal dissipation is an unlikely explanation for the good alignment observed today, because realignment happens on the same timescale as spin-orbit synchronization, and the stars in EP Cru are far from synchronization (they are spinning nine times too quickly). Therefore it seems that some binaries form with aligned axes, while other superficially similar binaries are formed with misaligned axes.

  12. High energy chemical laser system

    DOEpatents

    Gregg, D.W.; Pearson, R.K.

    1975-12-23

    A high energy chemical laser system is described wherein explosive gaseous mixtures of a reducing agent providing hydrogen isotopes and interhalogen compounds are uniformly ignited by means of an electrical discharge, flash- photolysis or an electron beam. The resulting chemical explosion pumps a lasing chemical species, hydrogen fluoride or deuterium fluoride which is formed in the chemical reaction. The generated lasing pulse has light frequencies in the 3- micron range. Suitable interhalogen compounds include bromine trifluoride (BrF$sub 3$), bromine pentafluoride (BrF$sub 5$), chlorine monofluoride (ClF), chlorine trifluoride (ClF$sub 3$), chlorine pentafluoride (ClF$sub 5$), iodine pentafluoride (IF$sub 5$), and iodine heptafluoride (IF$sub 7$); and suitable reducing agents include hydrogen (H$sub 2$), hydrocarbons such as methane (CH$sub 4$), deuterium (D$sub 2$), and diborane (B$sub 2$H$sub 6$), as well as combinations of the gaseous compound and/or molecular mixtures of the reducing agent.

  13. Autogeneous Laser and Hybrid Laser Arc Welding of T-joint Low Alloy Steel with Fiber Laser Systems

    NASA Astrophysics Data System (ADS)

    Unt, A.; Lappalainen, E.; Salminen, A.

    This paper is focused on the welding of low alloy steels S355 and AH36 in thicknesses 6, 8 and 10 mm in T-joint configuration using either autogeneous laser welding or laser-arc hybrid welding (HLAW) with high power fiber lasers. The aim was to obtain understanding of the factors influencing the size of the fillet and weld geometry through methodologically studying effects of laser power, welding speed, beam alignment relative to surface, air gap, focal point position and order of processes (in case of HLAW) and to get a B quality class welds in all thicknesses after parameter optimization.

  14. 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.

  15. An Integrated Support and Alignment System for Large ILC Lattice Elements

    SciTech Connect

    Viola, Robert

    2013-05-15

    The manipulators used to support and position lattice elements are critical components of all particle accelerators. The increased use of large superconducting magnets and accelerator modules places even greater demands on these manipulators. However, the performance of these support systems has not kept pace with the advances made in other areas of accelerator technology. This results in accelerators that are difficult to align and may not be capable of achieving target luminosities. An innovative new type of positioning mechanism tailored to the requirements of the International Linear Collider is proposed. The Tri-Sphere System provides secure support for large lattice elements and precision adjustment in six degrees of freedom. Integrated target sockets allow the support system to be rapidly pre-aligned. The system's kinematic design passively guides lattice elements into their correct location during installation. A complimentary Portable Actuation Unit provides the advantages of automated adjustment and allows these adjustments to be completely decoupled from surveying.

  16. Target Assembly to Check Boresight Alignment of Active Sensors

    NASA Technical Reports Server (NTRS)

    Ramos-Izquierdo, Luis; Scott, V. Stanley; Riris, Haris; Cavanaugh, John; Liiva, Peter; Rodriguez, Michael

    2011-01-01

    A compact and portable target assembly (Fig. 1) has been developed to measure the boresite alignment of LRO's Lunar Orbiter Laser Altimeter (LOLA) instrument at the spacecraft level. The concept for this target assembly has evolved over many years with earlier versions used to test the Mars Observer Laser Altimeter (MOLA), the Geoscience Laser Altimeter System (GLAS), and the Mercury Laser Altimeter (MLA) space-based instruments.

  17. Microoptoelectromechanical system (MOEMS) based laser

    DOEpatents

    Hutchinson, Donald P.

    2003-11-04

    A method for forming a folded laser and associated laser device includes providing a waveguide substrate, micromachining the waveguide substrate to form a folded waveguide structure including a plurality of intersecting folded waveguide paths, forming a single fold mirror having a plurality of facets which bound all ends of said waveguide paths except those reserved for resonator mirrors, and disposing a pair of resonator mirrors on opposite sides of the waveguide to form a lasing cavity. A lasing material is provided in the lasing cavity. The laser can be sealed by disposing a top on the waveguide substrate. The laser can include a re-entrant cavity, where the waveguide substrate is disposed therein, the re-entrant cavity including the single fold mirror.

  18. Method for auto-alignment of digital optical phase conjugation systems based on digital propagation.

    PubMed

    Jang, Mooseok; Ruan, Haowen; Zhou, Haojiang; Judkewitz, Benjamin; Yang, Changhuei

    2014-06-16

    Optical phase conjugation (OPC) has enabled many optical applications such as aberration correction and image transmission through fiber. In recent years, implementation of digital optical phase conjugation (DOPC) has opened up the possibility of its use in biomedical optics (e.g. deep-tissue optical focusing) due to its ability to provide greater-than-unity OPC reflectivity (the power ratio of the phase conjugated beam and input beam to the OPC system) and its flexibility to accommodate additional wavefront manipulations. However, the requirement for precise (pixel-to-pixel matching) alignment of the wavefront sensor and the spatial light modulator (SLM) limits the practical usability of DOPC systems. Here, we report a method for auto-alignment of a DOPC system by which the misalignment between the sensor and the SLM is auto-corrected through digital light propagation. With this method, we were able to accomplish OPC playback with a DOPC system with gross sensor-SLM misalignment by an axial displacement of up to~1.5 cm, rotation and tip/tilt of ~5° and in-plane displacement of ~5 mm (dependent on the physical size of the sensor and the SLM). Our auto-alignment method robustly achieved a DOPC playback peak-to-background ratio (PBR) corresponding to more than ~30 % of the theoretical maximum. As an additional advantage, the auto-alignment procedure can be easily performed at will and, as such, allows us to correct for small mechanical drifts within the DOPC systems, thus overcoming a previously major DOPC system vulnerability. We believe that this reported method for implementing robust DOPC systems will broaden the practical utility of DOPC systems.

  19. Method for auto-alignment of digital optical phase conjugation systems based on digital propagation.

    PubMed

    Jang, Mooseok; Ruan, Haowen; Zhou, Haojiang; Judkewitz, Benjamin; Yang, Changhuei

    2014-06-16

    Optical phase conjugation (OPC) has enabled many optical applications such as aberration correction and image transmission through fiber. In recent years, implementation of digital optical phase conjugation (DOPC) has opened up the possibility of its use in biomedical optics (e.g. deep-tissue optical focusing) due to its ability to provide greater-than-unity OPC reflectivity (the power ratio of the phase conjugated beam and input beam to the OPC system) and its flexibility to accommodate additional wavefront manipulations. However, the requirement for precise (pixel-to-pixel matching) alignment of the wavefront sensor and the spatial light modulator (SLM) limits the practical usability of DOPC systems. Here, we report a method for auto-alignment of a DOPC system by which the misalignment between the sensor and the SLM is auto-corrected through digital light propagation. With this method, we were able to accomplish OPC playback with a DOPC system with gross sensor-SLM misalignment by an axial displacement of up to~1.5 cm, rotation and tip/tilt of ~5° and in-plane displacement of ~5 mm (dependent on the physical size of the sensor and the SLM). Our auto-alignment method robustly achieved a DOPC playback peak-to-background ratio (PBR) corresponding to more than ~30 % of the theoretical maximum. As an additional advantage, the auto-alignment procedure can be easily performed at will and, as such, allows us to correct for small mechanical drifts within the DOPC systems, thus overcoming a previously major DOPC system vulnerability. We believe that this reported method for implementing robust DOPC systems will broaden the practical utility of DOPC systems. PMID:24977504

  20. System design and implementation for the glass panel alignment and sealing tool for flat panel displays

    SciTech Connect

    Jordan, J.D.; Stromberg, P.G.; Kuszmaul, S.S.

    1996-10-16

    This report describes the system designed and fabricated for the National Center for Advanced Information Component Manufacturing (NCAICM) project number 9322-135. The system is a device capable of simultaneously aligning two glass plates and sealing them together with glass frit. The process development was divided into two phases. The first was thermal sealing in an ambient environment. The second was sealing a controlled environment in a vacuum.

  1. Alignment performance comparison between MFR and MDCO for a TMA optical system

    NASA Astrophysics Data System (ADS)

    Kang, Hyukmo; Oh, Eunsong; Kim, Sug-Whan

    2015-09-01

    In this study, we performed alignment state estimation simulations and compared the performance of two Computer Aided Alignment (hereafter CAA) algorithms i.e. `Merit Function Regression (MFR)' and `Multiple Design Configuration Optimization (MDCO)' for a TMA optical system. The former minimizes the merit function using multi-field wavefront error measurements from single configuration, while the latter minimizes the merit function using single-field measured wavefront error from multiple configurations. The optical system used is an unobscured three-mirror anastigmat (TMA) optical system of 70mm in diameter, and F/5.0. It is designed for an unmanned aerial vehicle for coastal water remote sensing. The TMA consists of two aspherical mirrors, a spherical mirror and a flat folding mirror. Based on the sensitivity analysis, we set the tilt x, y of tertiary mirror as a compensator, and not considered decenter of tertiary mirror because of its spherical characteristic. For the simulation, we introduced Gaussian distribution of initial misalignment to M3. It has the mean value of zero and standard deviation of 0.5 mrad. The initial simulation result of alignment state estimation shows that both algorithms can meet the alignment requirement, λ/10 RMS WFE at 633nm. However, when we includes measurement noise, the simulation result of MFR shows greater standard deviation in RMS WFE than that of MDCO. As for the measurement, the MDCO requires single on-axis field while the MFR requires multiple fields, we concluded that the MDCO is more practical method to align the off-axis TMA optics than MFR.

  2. Magnetically switched power supply system for lasers

    NASA Technical Reports Server (NTRS)

    Pacala, Thomas J. (Inventor)

    1987-01-01

    A laser power supply system is described in which separate pulses are utilized to avalanche ionize the gas within the laser and then produce a sustained discharge to cause the gas to emit light energy. A pulsed voltage source is used to charge a storage device such as a distributed capacitance. A transmission line or other suitable electrical conductor connects the storage device to the laser. A saturable inductor switch is coupled in the transmission line for containing the energy within the storage device until the voltage level across the storage device reaches a predetermined level, which level is less than that required to avalanche ionize the gas. An avalanche ionization pulse generating circuit is coupled to the laser for generating a high voltage pulse of sufficient amplitude to avalanche ionize the laser gas. Once the laser gas is avalanche ionized, the energy within the storage device is discharged through the saturable inductor switch into the laser to provide the sustained discharge. The avalanche ionization generating circuit may include a separate voltage source which is connected across the laser or may be in the form of a voltage multiplier circuit connected between the storage device and the laser.

  3. Target isolation system, high power laser and laser peening method and system using same

    DOEpatents

    Dane, C. Brent; Hackel, Lloyd A.; Harris, Fritz

    2007-11-06

    A system for applying a laser beam to work pieces, includes a laser system producing a high power output beam. Target delivery optics are arranged to deliver the output beam to a target work piece. A relay telescope having a telescope focal point is placed in the beam path between the laser system and the target delivery optics. The relay telescope relays an image between an image location near the output of the laser system and an image location near the target delivery optics. A baffle is placed at the telescope focal point between the target delivery optics and the laser system to block reflections from the target in the target delivery optics from returning to the laser system and causing damage.

  4. Probing Orbital Symmetry of Molecules Via Alignment-Dependent Ionization Probability and High-Order Harmonic Generation by Intense Lasers

    NASA Astrophysics Data System (ADS)

    Zhao, Song-Feng; Zhou, Xiao-Xin; Lin, C. D.

    It is shown that measurement of alignment-dependent ionization probability and high-order harmonic generation (HHG) of molecules in an intense laser field can be used to probe the orbital symmetry of molecules. In this review, recent progress of molecular tunneling ionization (MO-ADK) model of Tong et al. [Phys. Rev. A 66, 033402 (2002)] is first reviewed. In particular, an efficient method to obtain wavefunctions of linear molecules in the asymptotic region was developed by solving the time-independent Schrödinger equation with B-spline functions, and molecular potential energy surfaces were constructed based on the density functional theory. The accurate wavefunctions are used to extract improved structure parameters in the MO-ADK model. The loss of accuracy of the MO-ADK model in the low intensity multiphoton ionization regime is also addressed by comparing with the molecular Perelomov-Popov-Terent'ev (MO-PPT) model, the single-active-electron time-dependent Schrödinger equation (SAE-TDSE) method, and the experimental data. Finally, how the orbital symmetry affects the HHG of molecules within the strong-field approximation (SFA) was reviewed.

  5. Review Of Laser Lightcraft Propulsion System

    SciTech Connect

    Davis, Eric W.; Mead, Franklin B. Jr

    2008-04-28

    Laser-powered 'Lightcraft' systems that deliver nano-satellites to LEO have been studied for the Air Force Research Laboratory (AFRL). The study was built on the extensive Lightcraft laser propulsion technology already developed by theoretical and experimental work by the AFRL's Propulsion Directorate at Edwards AFB, CA. Here we review the history and engineering-physics of the laser Lightcraft system and its propulsive performance. We will also review the effectiveness and cost of a Lightcraft vehicle powered by a high-energy laser beam. One result of this study is the significant influence of laser wavelength on the power lost during laser beam propagation through Earth's atmosphere and in space. It was discovered that energy and power losses in the laser beam are extremely sensitive to wavelength for Earth-To-Orbit missions, and this significantly affects the amount of mass that can be placed into orbit for a given maximum amount of radiated power from a ground-based laser.

  6. New generation of medical laser systems

    NASA Astrophysics Data System (ADS)

    Konov, Vitali I.; Prokhorov, Alexander M.; Silenok, Alexander S.

    1990-09-01

    Advantages and fields of application for modern medical laser systems with fiber optic cables optical diagnostics of the irradiated zone and beam parameters optimized for concrete type of operation are considered.

  7. Multiple-laser-energy detection system

    NASA Technical Reports Server (NTRS)

    Jarrett, O., Jr.; Northam, G. B.

    1977-01-01

    Technique monitors energy output of each of four sequentially-pulsed dye lasers for the Airborne LIDAR Oceanographic Probing Experiment system. Fiber optics attached to output mirrors transmit optical signal proportional to output energy.

  8. Pulse shaping on the Nova laser system

    SciTech Connect

    Lawson, J.K.; Speck, D.R.; Bibeau, C.; Weiland, T.L.

    1989-02-06

    Inertial confinement fusion requires temporally shaped pulses to achieve high gain efficiency. Recently, we demonstrated the ability to produce complex temporal pulse shapes at high power at 0.35 microns on the Nova laser system. 2 refs., 2 figs.

  9. Research of laser ignition detection system

    NASA Astrophysics Data System (ADS)

    Yang, Feng; Zhao, Dong; Xu, Qie; Ai, Xin

    2010-10-01

    Laser ignition is an important means of detonation but the accuracy and security is requested strictly. Based on the above, two points were considered in the design: achieve ignition-Fiber-optical health monitoring in the condition of low-intensity light (ensure the safety of gunpowder); observant the explosive imaging. In the paper, the laser ignition equipment was designed with optical detection and inner optical imaging system for the real-time monitoring to the optical fiber and the process of ignition. This design greatly improved the reliability and the safety of laser ignition system and provided the guarantee for usage and industrialization.

  10. Laser power conversion system analysis, volume 1

    NASA Technical Reports Server (NTRS)

    Jones, W. S.; Morgan, L. L.; Forsyth, J. B.; Skratt, J. P.

    1979-01-01

    The orbit-to-orbit laser energy conversion system analysis established a mission model of satellites with various orbital parameters and average electrical power requirements ranging from 1 to 300 kW. The system analysis evaluated various conversion techniques, power system deployment parameters, power system electrical supplies and other critical supplies and other critical subsystems relative to various combinations of the mission model. The analysis show that the laser power system would not be competitive with current satellite power systems from weight, cost and development risk standpoints.

  11. Alignment mark signal simulation system for the optimum mark feature selection

    NASA Astrophysics Data System (ADS)

    Sato, Takashi; Endo, Ayako; Higashiki, Tatsuhiko; Ishigo, Kazutaka; Kono, Takuya; Sakamoto, Takashi; Shioyama, Yoshiyuki; Tanaka, Satoshi

    2004-05-01

    Recently the overlay accuracy has got seriously severe. For the accurate overlay, signal intensity and waveform from the topographical alignment mark has been examined by signal simulation. Actually these results have given good agreements with actual signal profiles, but it is difficult to select particular alignment marks in each mask level by the signal simulation. Even after mass production, many mark candidates leave in kerf area. To help the selection, we propose a mark TCAD system. It is a useful system for the mark selection with the signal simulation in advance. In our system, alignment mark signal can be very easily simulated after input of some process parameters and process of record (POR). The POR is read into the system and a process simulator makes stacked films on a wafer. Topographical marks are simulated from the stacked films and the resist pattern. The topographical marks are illuminated and reflected beams are produced. It is simulated how the reflected beams are imaged through inspection optics. We show two applications. This system is not only to predict and show a signal waveform, but also helpful to find optimum marks.

  12. The ARGOS laser system: green light for ground layer adaptive optics at the LBT

    NASA Astrophysics Data System (ADS)

    Raab, Walfried; Rabien, Sebastian; Gässler, Wolfgang; Esposito, Simone; Barl, Lothar; Borelli, Jose; Daysenroth, Matthias; Gemperlein, Hans; Kulas, Martin; Ziegleder, Julian

    2014-07-01

    We report on the development of the laser system of ARGOS, the multiple laser guide star adaptive optics system for the Large Binocular Telescope (LBT). The system uses a total of six high powered, pulsed Nd:YAG lasers frequency-doubled to a wavelength of 532 nm to generate a set of three guide stars above each of the LBT telescopes. The position of each of the LGS constellations on sky as well as the relative position of the individual laser guide stars within this constellation is controlled by a set of steerable mirrors and a fast tip-tilt mirror within the laser system. The entire opto-mechanical system is housed in two hermetically sealed and thermally controlled enclosures on the SX and DX side of the LBT telescope. The laser beams are propagated through two refractive launch telescopes which focus the beams at an altitude of 12 km, creating a constellation of laser guide stars around a 4 arcminute diameter circle by means of Rayleigh scattering. In addition to the GLAO Rayleigh beacon system, ARGOS has also been designed for a possible future upgrade with a hybrid sodium laser - Rayleigh beacon combination, enabling diffraction limited operation. The ARGOS laser system was successfully installed at the LBT in April 2013. Extensive functional tests have been carried out and have verified the operation of the systems according to specifications. The alignment of the laser system with respect to the launch telescope was carried out during two more runs in June and October 2013, followed by the first propagation of laser light on sky in November 2013.

  13. Target plane imaging system for the Nova laser

    SciTech Connect

    Swift, C.D.; Bliss, E.S.; Jones, W.A.; Reeves, R.J.; Seppala, L.G.; Shelton, R.T.; VanArsdall, P.J.

    1985-12-12

    The Nova laser, in operation since December 1984, is capable of irradiating targets with light at 1.05 ..mu..m, 0.53 ..mu..m, and 0.35 ..mu..m. Correct alignment of these harmonic beams uses a system called a target plane imager (TPI). It is a large microscope (four meters long, weighing one thousand kilograms) that relays images from the target chamber center to a video optics module located on the outside of the chamber. Several modes of operation are possible including: near-field viewing and far-field viewing at three magnifications and three wavelengths. In addition, the entire instrument can be scanned in X,Y,Z to examine various planes near chamber center. Performance of this system and its computer controls will be described.

  14. XUV free-electron laser-based projection lithography systems

    SciTech Connect

    Newnam, B.E.

    1990-01-01

    Free-electron laser sources, driven by rf-linear accelerators, have the potential to operate in the extreme ultraviolet (XUV) spectral range with more than sufficient average power for high-volume projection lithography. For XUV wavelengths from 100 nm to 4 nm, such sources will enable the resolution limit of optical projection lithography to be extended from 0.25 {mu}m to 0.05{mu}m and with an adequate total depth of focus (1 to 2 {mu}m). Recent developments of a photoinjector of very bright electron beams, high-precision magnetic undulators, and ring-resonator cavities raise our confidence that FEL operation below 100 nm is ready for prototype demonstration. We address the motivation for an XUV FEL source for commercial microcircuit production and its integration into a lithographic system, include reflecting reduction masks, reflecting XUV projection optics and alignment systems, and surface-imaging photoresists. 52 refs., 7 figs.

  15. Laser and solar-photovoltaic space power systems comparison. II.

    NASA Technical Reports Server (NTRS)

    De Young, R. J.; Stripling, J.; Enderson, T. M.; Humes, D. H.; Davis, W. T.

    1984-01-01

    A comparison of total system cost is made between solar photovoltaic and laser/receiver systems. The laser systems assume either a solar-pumped CO2 blackbody transfer laser with MHD receiver or a solar pumped liquid neodymium laser with a photovoltaic receiver. Total system costs are less for the laser systems below 300 km where drag is significant. System costs are highly dependent on altitude.

  16. Repetitive output laser system and method using target reflectivity

    DOEpatents

    Johnson, Roy R.

    1978-01-01

    An improved laser system and method for implosion of a thermonuclear fuel pellet in which that portion of a laser pulse reflected by the target pellet is utilized in the laser system to initiate a succeeding target implosion, and in which the energy stored in the laser system to amplify the initial laser pulse, but not completely absorbed thereby, is used to amplify succeeding laser pulses initiated by target reflection.

  17. Alignment and integration of large optical systems based on advanced metrology.

    NASA Astrophysics Data System (ADS)

    Aliverti, M.; Riva, M.; Moschetti, M.; Pariani, G.; Genoni, M.; Zerbi, F. M.

    Optical alignment is a key activity in opto-mechanical system Integration. Traditional techniques require adjustable mounting, driven by optical references that allows the tuning of the optics position along all 6 Degree of Freedom. Nevertheless, the required flexibility imposes reduced stiffness and consequently less stability of the system. The Observatory of Brera (OAB) started few years ago a research activity focused onto the overcoming of this limits exploiting the high metrology performances of Coordinate Measuring Machines (CMM) with the main objectives of relax the manufacturing tolerances and maximize mounting stiffness. Through the T-REX grants, OAB acquired all the instrumentation needed for that activity furthermore considering the ESPRESSO project training and testing also oriented to large scale instrumentation like the E-ELT one. We will present in this paper the definition of the VLTs convergence point and the feasibility study of large mirrors alignment done by mechanical measurements methods. skip=8pt

  18. Automated retinal robotic laser system instrumentation

    NASA Astrophysics Data System (ADS)

    Barrett, Steven F.; Wright, Cameron H. G.; Jerath, Maya R.; Lewis, R. Stephen, II; Dillard, Bryan C.; Rylander, Henry G., III; Welch, Ashley J.

    1995-05-01

    Researchers at the University of Texas at Austin's Biomedical Engineering Laser Laboratory investigating the medical applications of lasers have worked toward the development of a retinal robotic laser system. The ultimate goal of this ongoing project is to precisely place and control the depth of laser lesions for the treatment of various retinal diseases such as diabetic retinopathy and retinal tears. Researchers at the USAF Academy's Department of Electrical Engineering have also become involved with this research due to similar interests. Separate low speed prototype subsystems have been developed to control lesion depth using lesion reflectance feedback parameters and lesion placement using retinal vessels as tracking landmarks. Both subsystems have been successfully demonstrated in vivo on pigmented rabbits using an argon continuous wave laser. Work is ongoing to build a prototype system to simultaneously control lesion depth and placement. The instrumentation aspects of the prototype subsystems were presented at SPIE Conference 1877 in January 1993. Since then our efforts have concentrated on combining the lesion depth control subsystem and the lesion placement subsystem into a single prototype capable of simultaneously controlling both parameters. We have designed this combined system CALOSOS for Computer Aided Laser Optics System for Ophthalmic Surgery. An initial CALOSOS prototype design is provided. We have also investigated methods to improve system response time. The use of high speed non-standard frame rate CCD cameras and high speed local bus frame grabbers hosted on personal computers are being investigated. A review of system testing in vivo to date is provided in SPIE Conference proceedings 2374-49 (Novel Applications of Lasers and Pulsed Power, Dual-Use Applications of Lasers: Medical session).

  19. Laser Inertial Fusion Energy Control Systems

    SciTech Connect

    Marshall, C; Carey, R; Demaret, R; Edwards, O; Lagin, L; Van Arsdall, P

    2011-03-18

    A Laser Inertial Fusion Energy (LIFE) facility point design is being developed at LLNL to support an Inertial Confinement Fusion (ICF) based energy concept. This will build upon the technical foundation of the National Ignition Facility (NIF), the world's largest and most energetic laser system. NIF is designed to compress fusion targets to conditions required for thermonuclear burn. The LIFE control systems will have an architecture partitioned by sub-systems and distributed among over 1000's of front-end processors, embedded controllers and supervisory servers. LIFE's automated control subsystems will require interoperation between different languages and target architectures. Much of the control system will be embedded into the subsystem with well defined interface and performance requirements to the supervisory control layer. An automation framework will be used to orchestrate and automate start-up and shut-down as well as steady state operation. The LIFE control system will be a high parallel segmented architecture. For example, the laser system consists of 384 identical laser beamlines in a 'box'. The control system will mirror this architectural replication for each beamline with straightforward high-level interface for control and status monitoring. Key technical challenges will be discussed such as the injected target tracking and laser pointing feedback. This talk discusses the the plan for controls and information systems to support LIFE.

  20. Fast Offset Laser Phase-Locking System

    NASA Technical Reports Server (NTRS)

    Shaddock, Daniel; Ware, Brent

    2008-01-01

    Figure 1 shows a simplified block diagram of an improved optoelectronic system for locking the phase of one laser to that of another laser with an adjustable offset frequency specified by the user. In comparison with prior systems, this system exhibits higher performance (including higher stability) and is much easier to use. The system is based on a field-programmable gate array (FPGA) and operates almost entirely digitally; hence, it is easily adaptable to many different systems. The system achieves phase stability of less than a microcycle. It was developed to satisfy the phase-stability requirement for a planned spaceborne gravitational-wave-detecting heterodyne laser interferometer (LISA). The system has potential terrestrial utility in communications, lidar, and other applications. The present system includes a fast phasemeter that is a companion to the microcycle-accurate one described in High-Accuracy, High-Dynamic-Range Phase-Measurement System (NPO-41927), NASA Tech Briefs, Vol. 31, No. 6 (June 2007), page 22. In the present system (as in the previously reported one), beams from the two lasers (here denoted the master and slave lasers) interfere on a photodiode. The heterodyne photodiode output is digitized and fed to the fast phasemeter, which produces suitably conditioned, low-latency analog control signals which lock the phase of the slave laser to that of the master laser. These control signals are used to drive a thermal and a piezoelectric transducer that adjust the frequency and phase of the slave-laser output. The output of the photodiode is a heterodyne signal at the difference between the frequencies of the two lasers. (The difference is currently required to be less than 20 MHz due to the Nyquist limit of the current sampling rate. We foresee few problems in doubling this limit using current equipment.) Within the phasemeter, the photodiode-output signal is digitized to 15 bits at a sampling frequency of 40 MHz by use of the same analog

  1. 42 CFR 414.1225 - Alignment of Physician Quality Reporting System quality measures and quality measures for the...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 3 2013-10-01 2013-10-01 false Alignment of Physician Quality Reporting System quality measures and quality measures for the value-based payment modifier. 414.1225 Section 414.1225... Payment Modifier Under the Physician Fee Schedule § 414.1225 Alignment of Physician Quality...

  2. 42 CFR 414.1225 - Alignment of Physician Quality Reporting System quality measures and quality measures for the...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 3 2014-10-01 2014-10-01 false Alignment of Physician Quality Reporting System quality measures and quality measures for the value-based payment modifier. 414.1225 Section 414.1225... Payment Modifier Under the Physician Fee Schedule § 414.1225 Alignment of Physician Quality...

  3. An optimized fiber delivery system for Q-switched, Nd:YAG lasers

    SciTech Connect

    Setchell, R.E.

    1996-11-01

    Interest in the transmission of high intensities through optical fibers is being motivated by an increasing number of applications. Using different laser types and fiber materials, various studies are encountering transmission limitations due to laser-induced damage processes. The authors have found that fiber transmission is often limited by a plasma-forming breakdown occurring at the fiber entrance face. System attributes that will affect breakdown and damage thresholds include laser characteristics, the design and alignment of laser-to-fiber injection optics, and fiber end-face preparation. In the present work the authors have combined insights gained in past studies in order to establish what thresholds can be achieved if all system attributes can be optimized to some degree. The multimode laser utilized past modifications that produced a relatively smooth, quasi-Gaussian profile. The laser-to-fiber injection system achieved a relatively low value for the ratio of peak-to-average fluences at the fiber entrance face, incorporated a mode scrambler to generate a broad mode power distribution within the initial segment of the fiber path, and had improved fixturing to insure that the fiber axis was collinear with the incident laser beam. Fiber end faces were prepared by a careful mechanical polishing schedule followed by surface conditioning using a CO{sub 2} laser. In combination, these factors resulted in higher thresholds for breakdown and damage than they had achieved previously in studies that utilized a simple lens injection system.

  4. Experimental nonlinear laser systems: Bigger data for better science?

    SciTech Connect

    Kane, D. M.; Toomey, J. P.; McMahon, C.; Noblet, Y.; Argyris, A.; Syvridis, D.

    2014-10-06

    Bigger data is supporting knowledge discovery in nonlinear laser systems as will be demonstrated with examples from three semiconductor laser based systems – one with optical feedback, a photonic integrated circuit (PIC) chaotic laser and a frequency shifted feedback laser system.

  5. 21 CFR 884.6200 - Assisted reproduction laser system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction laser system. 884.6200... Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a device that images, targets, and controls the power and pulse duration of a laser beam used to ablate a...

  6. Advanced laser systems for photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Klosner, Marc; Sampathkumar, Ashwin; Chan, Gary; Wu, Chunbai; Gross, Daniel; Heller, Donald F.

    2015-03-01

    We describe the ongoing development of laser systems for advanced photoacoustic imaging (PAI). We discuss the characteristics of these laser systems and their particular benefits for soft tissue imaging and next-generation breast cancer diagnostics. We provide an overview of laser performance and compare this with other laser systems that have been used for early-stage development of PAI. These advanced systems feature higher pulse energy output at clinically relevant repetition rates, as well as a novel wavelength-cycling output pulse format. Wavelength cycling provides pulse sequences for which the output repeatedly alternates between two wavelengths that provide differential imaging. This capability improves co-registration of captured differential images. We present imaging results of phantoms obtained with a commercial ultrasound detector system and a wavelength-cycling laser source providing ~500 mJ/pulse at 755 and 797 nm, operating at 25 Hz. The results include photoacoustic images and corresponding pulse-echo data from a tissue mimicking phantom containing inclusions, simulating tumors in the breast. We discuss the application of these systems to the contrast-enhanced detection of various tissue types and tumors.

  7. Satellite Power Systems (SPS) laser studies. Volume 1: Laser environmental impact study

    NASA Technical Reports Server (NTRS)

    Beverly, R. E., III

    1980-01-01

    The environmental impact of space to Earth power transmission using space borne laser subsystems is emphasized. A laser system is defined, estimates of relevant efficiencies for laser power generation and atmospheric transmission are developed, and a comparison is made to a microwave system. Ancillary issues, such as laser beam spreading, safety and security, mass and volume estimates and technology growth are considered.

  8. Spontaneous alignment in charged-particle systems: Fixed-length vs micellar situations

    NASA Astrophysics Data System (ADS)

    McMullen, William; Gelbart, William M.; Rosenfeld, Yaakov

    1986-07-01

    We use a recently developed version of the soft-mean-spherical approximation (SMSA) to treat spontaneous alignment in suspensions of ionic, rod-like particles. In particular our theory derives from the charge-smearing idea of Onsager in which a lower bound is established for the free energy of the interacting system. First we treat the usual case of fixed-particle lengths and establish the regimes in which the charged lines behave like hard spherocylinders (i.e., the ``smearing'' length plays the role of a hard-core diameter). In general, the nematic phase is superceded by the solid whenever the rod length is too small or too large. Then we consider explicitly the micellar situation in which the particle lengths are determined by the thermodynamics (and vice versa). Here we find the possibility of a reentrant isotropic phase. At low temperatures the nematic becomes unstable because the alignment-induced growth leads to too large a charging (``self'') energy for the micelles. We also predict an ideal solution-like behavior for the growth of micelles in sufficiently concentrated isotropic phases. Finally we comment on the differences between our charge-smearing description of spontaneous alignment in ionic systems and a collective-coordinate approach due to Deutsch and Goldenfeld.

  9. Characterization of electrode alignment for optimal droplet charging and actuation in droplet-based microfluidic system.

    PubMed

    Ahn, Myung Mo; Im, Do Jin; Yoo, Byeong Sun; Kang, In Seok

    2015-09-01

    The actuation method using electric force as a driving force is utilized widely in droplet-based microfluidic systems. In this work, the effects of charging electrode alignment on direct charging of a droplet on electrified electrodes and a subsequent electrophoretic control of the droplet are investigated. The charging characteristics of a droplet according to different electrode alignments are quantitatively examined through experiments and systematic numerical simulations with varying distances and angles between the two electrodes. The droplet charge acquired from the electrified electrode is directly proportional to the distance and barely affected by the angle between the two electrodes. This implies that the primary consideration of electrode alignment in microfluidic devices is the distance between electrodes and the insignificant effect of angle provides a great degree of freedom in designing such devices. Not only the droplet charge acquired from the electrode but also the force exerted on the droplet is analyzed. Finally, the implications and design guidance for microfluidic systems are discussed with an electrophoresis of a charged droplet method-based digital microfluidic device.

  10. Alignment of a multilayer-coated imaging system using extreme ultraviolet Foucault and Ronchi interferometric testing

    SciTech Connect

    Ray-Chaudhuri, A.K.; Ng, W.; Cerrina, F.; Tan, Z.; Bjorkholm, J.; Tennant, D.; Spector, S.J.

    1995-11-01

    Multilayer-coated imaging systems for extreme ultraviolet (EUV) lithography at 13 nm represent a significant challenge for alignment and characterization. The standard practice of utilizing visible light interferometry fundamentally provides an incomplete picture since this technique fails to account for phase effects induced by the multilayer coating. Thus the development of optical techniques at the functional EUV wavelength is required. We present the development of two EUV optical tests based on Foucault and Ronchi techniques. These relatively simple techniques are extremely sensitive due to the factor of 50 reduction in wavelength. Both techniques were utilized to align a Mo--Si multilayer-coated Schwarzschild camera. By varying the illumination wavelength, phase shift effects due to the interplay of multilayer coating and incident angle were uniquely detected. {copyright} {ital 1995} {ital American} {ital Vacuum} {ital Society}

  11. An autocollimator alignment system for a Schwarzschild-Couder Cherenkov telescope

    NASA Astrophysics Data System (ADS)

    Griffiths, S. T.; Kaaret, P.; Smith, E.

    2016-08-01

    We present a digital autocollimator which will be used in the alignment system of a prototype medium-sized telescope, which is part of the U.S. contribution to the Cherenkov Telescope Array (CTA). The Schwarzschild-Couder optics in the prototype telescope (which is currently under construction) requires the precise alignment of three components: the primary and secondary segmented mirrors, and the gamma-ray camera. The approximately 9 meter separation between the mirrors necessitates remote optical measurement. Our autocollimator will measure the angle of a segment in one mirror relative to the center of the other mirror with a precision better than 5 arcsec over a range of ±0.126 °. We present a detailed description of the instrument and describe its performance in the laboratory.

  12. Cutting laser systems for ureteral strictures

    NASA Astrophysics Data System (ADS)

    Durek, C.; Knipper, Ansgar; Brinkmann, Ralf; Miller, Ado; Gromoll, Bernd; Jocham, Dieter

    1994-02-01

    Acquired ureteral strictures are still treated either with a stent, balloon dilatation, by open surgery or by endoscopic therapy with a `cold knife' or high current density as intubated ureterotomy. The success rates described in the literature range between 50% and 90%. Using the experimental CTH:YAG laser (wavelength 2120 nm) and CT:YAG laser (wavelength 1950 nm), the reduction of invasiveness and of morbidity was evaluated. First, the CTH:YAG laser was investigated on 540 fresh porcine ureters varying the parameters. With a computerized morphometry system, defect depth, defect width, coagulation depth and coagulation width were measured. Then 21 female pigs underwent 7.5 F - 12 F ureteroscopy with CTH:YAG laser, CT:YAG laser, high current density and `cold knife' ureterotomy. An IVP and sacrification with explanation of the whole urinary tract was done on day 6 and around day 60. In practice, laser application via the endoscope was easy to handle and exact cutting was always seen. The CT:YAG laser seems to have the best success results with low ureteral stricture recurrence rates. However, its clinical use remains to be proven.

  13. Multiple target laser ablation system

    DOEpatents

    Mashburn, Douglas N.

    1996-01-01

    A laser ablation apparatus and method are provided in which multiple targets consisting of material to be ablated are mounted on a movable support. The material transfer rate is determined for each target material, and these rates are stored in a controller. A position detector determines which target material is in a position to be ablated, and then the controller controls the beam trigger timing and energy level to achieve a desired proportion of each constituent material in the resulting film.

  14. Multiple target laser ablation system

    DOEpatents

    Mashburn, D.N.

    1996-01-09

    A laser ablation apparatus and method are provided in which multiple targets consisting of material to be ablated are mounted on a movable support. The material transfer rate is determined for each target material, and these rates are stored in a controller. A position detector determines which target material is in a position to be ablated, and then the controller controls the beam trigger timing and energy level to achieve a desired proportion of each constituent material in the resulting film. 3 figs.

  15. X-ray laser system, x-ray laser and method

    DOEpatents

    London, Richard A.; Rosen, Mordecai D.; Strauss, Moshe

    1992-01-01

    Disclosed is an x-ray laser system comprising a laser containing generating means for emitting short wave length radiation, and means external to said laser for energizing said generating means, wherein when the laser is in an operative mode emitting radiation, the radiation has a transverse coherence length to width ratio of from about 0.05 to 1. Also disclosed is a method of adjusting the parameters of the laser to achieve the desired coherence length to laser width ratio.

  16. Laser/rf personnel identification system

    NASA Astrophysics Data System (ADS)

    Zari, Michael C.; Ward, Reeder N.; Hess, David A.; Anderson, Christopher S.

    1995-05-01

    This paper documents the design of a Laser/RF Personnel Identification System developed for the US Army Communications and Electronics Command (CECOM) for soldier identification. The system has dual use applications, including law enforcement officer protection, and includes a laser interrogation unit with a programmable activation code. The interrogation unit is very directive for low probability of intercept (LPI), which is of interest during covert operations. A responder unit, worn by the law enforcement personnel or soldier, transmits an LPI radio frequency (RF) response only after receiving the proper interrogation code. The basic subsystems for the identification system are a laser interrogation unit, an RF responder unit, and a programming/synchronization unit. In this paper, the operating principles for the subsystems are reviewed and design issues are discussed. In addition to the design performed for CECOM, a breadboard system was developed to validate the concept. Hardware implementation is reviewed and field testing of the breadboard is presented.

  17. Laser surveillance system for spent fuel

    SciTech Connect

    Fiarman, S; Zucker, M S; Bieber, Jr, A M

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a laser system and have used it with a simulated BWR assembly. The reflected signal from the zircaloy rods depends on the position of the assembly, but in all cases is easily discernable from the reference scan of background with no assembly.

  18. A pulsed-laser calibration system for the laser backscatter diagnostics at the Omega laser

    SciTech Connect

    Neumayer, P; Sorce, C; Froula, D H; Rekow, V; Loughman, K; Knight, R; Glenzer, S H; Bahr, R; Seka, W

    2009-10-09

    A calibration system has been developed that allows a direct determination of the sensitivity of the laser backscatter diagnostics at the Omega laser. A motorized mirror at the target location redirects individual pulses of a mJ-class laser onto the diagnostic to allow the in-situ measurement of the local point response of the backscatter diagnostics. Featuring dual wavelength capability at the 2nd and 3rd harmonic of the Nd:YAG laser, both spectral channels of the backscatter diagnostics can be directly calibrated. In addition, channel cross-talk and polarization sensitivity can be determined. The calibration system has been employed repeatedly over the last two years and has enabled precise backscatter measurements of both stimulated Brillouin scattering and stimulated Raman scattering in gas-filled hohlraum targets that emulate conditions relevant to those in inertial confinement fusion targets.

  19. Fiber laser front end for high energy petawatt laser systems

    SciTech Connect

    Dawson, J W; Messerly, M J; Phan, H; Mitchell, S; Drobshoff, A; Beach, R J; Siders, C; Lucianetti, A; Crane, J K; Barty, C J

    2006-06-15

    We are developing a fiber laser front end suitable for high energy petawatt laser systems on large glass lasers such as NIF. The front end includes generation of the pulses in a fiber mode-locked oscillator, amplification and pulse cleaning, stretching of the pulses to >3ns, dispersion trimming, timing, fiber transport of the pulses to the main laser bay and amplification of the pulses to an injection energy of 150 {micro}J. We will discuss current status of our work including data from packaged components. Design detail such as how the system addresses pulse contrast, dispersion trimming and pulse width adjustment and impact of B-integral on the pulse amplification will be discussed. A schematic of the fiber laser system we are constructing is shown in figure 1 below. A 40MHz packaged mode-locked fiber oscillator produces {approx}1nJ pulses which are phase locked to a 10MHz reference clock. These pulses are down selected to 100kHz and then amplified while still compressed. The amplified compressed pulses are sent through a non-linear polarization rotation based pulse cleaner to remove background amplified spontaneous emission (ASE). The pulses are then stretched by a chirped fiber Bragg grating (CFBG) and then sent through a splitter. The splitter splits the signal into two beams. (From this point we follow only one beam as the other follows an identical path.) The pulses are sent through a pulse tweaker that trims dispersion imbalances between the final large optics compressor and the CFBG. The pulse tweaker also permits the dispersion of the system to be adjusted for the purpose of controlling the final pulse width. Fine scale timing between the two beam lines can also be adjusted in the tweaker. A large mode area photonic crystal single polarization fiber is used to transport the pulses from the master oscillator room to the main laser bay. The pulses are then amplified a two stage fiber amplifier to 150mJ. These pulses are then launched into the main amplifier

  20. Low-cost laser diagnostic system

    NASA Astrophysics Data System (ADS)

    Ramos, T. J.; Lim, D. R.; Lingenfelter, A. C.

    1985-10-01

    The principal feature of a new laser diagnostic system is real-time display of beam energy profile. This ensures on-line verification of beam mode and stability with capability for computer storage of this information for later analysis. This system provides low-cost control and repeatability, essential in precision metalworking operations.

  1. A Modular Laser Graphics Projection System

    NASA Astrophysics Data System (ADS)

    Newswanger, Craig D.

    1984-05-01

    WED Enterprises has designed and built a modular projection system for the presentation of animated laser shows. This system was designed specifically for use in Disney theme shows. Its modular design allows it to be adapted to many show situations with simple hardware and software adjustments. The primary goals were superior animation, long life, low maintenance and stand alone operation.

  2. Use of a Laser Videodisc System: Attitudes.

    ERIC Educational Resources Information Center

    Kelly, Sarah A.

    1988-01-01

    Describes a study that assessed the attitudes of novice searchers before and after using a laser videodisk system. The discussion covers the relationships between the users' initial attitudes, prior computer experience, and success in using the videodisk system. (11 references) (Author/CLB)

  3. Laser tracking system with automatic reacquisition capability.

    PubMed

    Johnson, R E; Weiss, P F

    1968-06-01

    A laser based tracking system is described that has the capability of automatically performing an acquisition search to locate the target. This work is intended for precision launch phase tracking of the Saturn V launch vehicle. System tracking accuracies limited only by the atmosphere have been demonstrated, as has acquisition over a 1 degrees x 1 degrees field of view.

  4. Optimal Parameter Design of Coarse Alignment for Fiber Optic Gyro Inertial Navigation System

    PubMed Central

    Lu, Baofeng; Wang, Qiuying; Yu, Chunmei; Gao, Wei

    2015-01-01

    Two different coarse alignment algorithms for Fiber Optic Gyro (FOG) Inertial Navigation System (INS) based on inertial reference frame are discussed in this paper. Both of them are based on gravity vector integration, therefore, the performance of these algorithms is determined by integration time. In previous works, integration time is selected by experience. In order to give a criterion for the selection process, and make the selection of the integration time more accurate, optimal parameter design of these algorithms for FOG INS is performed in this paper. The design process is accomplished based on the analysis of the error characteristics of these two coarse alignment algorithms. Moreover, this analysis and optimal parameter design allow us to make an adequate selection of the most accurate algorithm for FOG INS according to the actual operational conditions. The analysis and simulation results show that the parameter provided by this work is the optimal value, and indicate that in different operational conditions, the coarse alignment algorithms adopted for FOG INS are different in order to achieve better performance. Lastly, the experiment results validate the effectiveness of the proposed algorithm. PMID:26121614

  5. Optimal Parameter Design of Coarse Alignment for Fiber Optic Gyro Inertial Navigation System.

    PubMed

    Lu, Baofeng; Wang, Qiuying; Yu, Chunmei; Gao, Wei

    2015-01-01

    Two different coarse alignment algorithms for Fiber Optic Gyro (FOG) Inertial Navigation System (INS) based on inertial reference frame are discussed in this paper. Both of them are based on gravity vector integration, therefore, the performance of these algorithms is determined by integration time. In previous works, integration time is selected by experience. In order to give a criterion for the selection process, and make the selection of the integration time more accurate, optimal parameter design of these algorithms for FOG INS is performed in this paper. The design process is accomplished based on the analysis of the error characteristics of these two coarse alignment algorithms. Moreover, this analysis and optimal parameter design allow us to make an adequate selection of the most accurate algorithm for FOG INS according to the actual operational conditions. The analysis and simulation results show that the parameter provided by this work is the optimal value, and indicate that in different operational conditions, the coarse alignment algorithms adopted for FOG INS are different in order to achieve better performance. Lastly, the experiment results validate the effectiveness of the proposed algorithm. PMID:26121614

  6. Airborne space laser communication system and experiments

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Ming; Zhang, Li-zhong; Meng, Li-Xin

    2015-11-01

    Airborne space laser communication is characterized by its high speed, anti-electromagnetic interference, security, easy to assign. It has broad application in the areas of integrated space-ground communication networking, military communication, anti-electromagnetic communication. This paper introduce the component and APT system of the airborne laser communication system design by Changchun university of science and technology base on characteristic of airborne laser communication and Y12 plan, especially introduce the high communication speed and long distance communication experiment of the system that among two Y12 plans. In the experiment got the aim that the max communication distance 144Km, error 10-6 2.5Gbps - 10-7 1.5Gbps capture probability 97%, average capture time 20s. The experiment proving the adaptability of the APT and the high speed long distance communication.

  7. Injection mode-locking Ti-sapphire laser system

    DOEpatents

    Hovater, James Curtis; Poelker, Bernard Matthew

    2002-01-01

    According to the present invention there is provided an injection modelocking Ti-sapphire laser system that produces a unidirectional laser oscillation through the application of a ring cavity laser that incorporates no intracavity devices to achieve unidirectional oscillation. An argon-ion or doubled Nd:YVO.sub.4 laser preferably serves as the pump laser and a gain-switched diode laser serves as the seed laser. A method for operating such a laser system to produce a unidirectional oscillating is also described.

  8. Accidental human laser retinal injuries from military laser systems

    NASA Astrophysics Data System (ADS)

    Stuck, Bruce E.; Zwick, Harry; Molchany, Jerome W.; Lund, David J.; Gagliano, Donald A.

    1996-04-01

    The time course of the ophthalmoscopic and functional consequences of eight human laser accident cases from military laser systems is described. All patients reported subjective vision loss with ophthalmoscopic evidence of retinal alteration ranging from vitreous hemorrhage to retinal burn. Five of the cases involved single or multiple exposures to Q-switched neodymium radiation at close range whereas the other three incidents occur over large ranges. Most exposures were within 5 degrees of the foveola, yet none directly in the foveola. High contrast visual activity improved with time except in the cases with progressive retinal fibrosis between lesion sites or retinal hole formation encroaching the fovea. In one patient the visual acuity recovered from 20/60 at one week to 20/25 in four months with minimal central visual field loss. Most cases showed suppression of high and low spatial frequency contrast sensitivity. Visual field measurements were enlarged relative to ophthalmoscopic lesion size observations. Deep retinal scar formation and retinal traction were evident in two of the three cases with vitreous hemorrhage. In one patient, nerve fiber layer damage to the papillo-macular bundle was clearly evident. Visual performance measured with a pursuit tracking task revealed significant performance loss relative to normal tracking observers even in cases where acuity returned to near normal levels. These functional and performance deficits may reflect secondary effects of parafoveal laser injury.

  9. Software Development for the Hobby-Eberly Telescope's Segment Alignment Maintenance System using LABView

    NASA Technical Reports Server (NTRS)

    Hall, Drew P.; Ly, William; Howard, Richard T.; Weir, John; Rakoczy, John; Roe, Fred (Technical Monitor)

    2002-01-01

    The software development for an upgrade to the Hobby-Eberly Telescope (HET) was done in LABView. In order to improve the performance of the HET at the McDonald Observatory, a closed-loop system had to be implemented to keep the mirror segments aligned during periods of observation. The control system, called the Segment Alignment Maintenance System (SAMs), utilized inductive sensors to measure the relative motions of the mirror segments. Software was developed in LABView to tie the sensors, operator interface, and mirror-control motors together. Developing the software in LABView allowed the system to be flexible, understandable, and able to be modified by the end users. Since LABView is built using block diagrams, the software naturally followed the designed control system's block and flow diagrams, and individual software blocks could be easily verified. LABView's many built-in display routines allowed easy visualization of diagnostic and health-monitoring data during testing. Also, since LABView is a multi-platform software package, different programmers could develop the code remotely on various types of machines. LABView s ease of use facilitated rapid prototyping and field testing. There were some unanticipated difficulties in the software development, but the use of LABView as the software "language" for the development of SAMs contributed to the overall success of the project.

  10. A multi-beam, multi-terawatt Ti:sapphire laser system for laser wake-field acceleration studies

    SciTech Connect

    Toth, Cs.; Geddes, C.G.R.; Tilborg, J. van; Leemans, W.P.

    2004-12-07

    The Lasers, Optical Accelerator Systems Integrated Studies (L'OASIS) Lab of LBNL operates a highly automated and remotely controlled Ti:sapphire chirped pulse amplification (CPA) laser system that provides synchronized beams of 2x1.0 TW, 12 TW, and 100 TW peak-power, in a unique, radiation shielded facility. The system has been specially designed for studying high field laser-plasma interactions and particularly aimed for the investigations of laser wake-field particle acceleration. It generates and recombines multiple beams having different pulse durations, wavelengths, and pulse energies for various stages of plasma preparation, excitation, and diagnostics. The amplifier system is characterized and continuously monitored via local area network (LAN) from a radiation shielded control room by an array of diagnostics, including beam profile monitoring cameras, remote controlled alignment options, self-correcting beam-pointing stabilization loops, pulse measurement tools, such as single-shot autocorrelator for pulse duration and third-order correlator for contrast measurements, FROG for pulse shape studies.

  11. Laser system for distance, velocity, and angle measurements

    NASA Astrophysics Data System (ADS)

    Pienkowski, Janusz; Rzepka, Janusz

    1995-03-01

    The two frequency laser interferometer, using frequency stabilized HeNe laser 0.63 micrometers , is presented in this paper. The system consists of a laser head, meteo station, and measurement display. The laser system fundamentally measures linear displacement (distance) but can also measure velocity and angle. The resolution and the accuracy of measurements are comparable with parameters of lasers systems produced by Hewlett-Packard 5526A and Spindler & Hoyer ZLI 150.

  12. Injection locked oscillator system for pulsed metal vapor lasers

    DOEpatents

    Warner, Bruce E.; Ault, Earl R.

    1988-01-01

    An injection locked oscillator system for pulsed metal vapor lasers is disclosed. The invention includes the combination of a seeding oscillator with an injection locked oscillator (ILO) for improving the quality, particularly the intensity, of an output laser beam pulse. The present invention includes means for matching the first seeder laser pulses from the seeding oscillator to second laser pulses of a metal vapor laser to improve the quality, and particularly the intensity, of the output laser beam pulse.

  13. MUSE alignment onto VLT

    NASA Astrophysics Data System (ADS)

    Laurent, Florence; Renault, Edgard; Boudon, Didier; Caillier, Patrick; Daguisé, Eric; Dupuy, Christophe; Jarno, Aurélien; Lizon, Jean-Louis; Migniau, Jean-Emmanuel; Nicklas, Harald; Piqueras, Laure

    2014-07-01

    MUSE (Multi Unit Spectroscopic Explorer) is a second generation Very Large Telescope (VLT) integral field spectrograph developed for the European Southern Observatory (ESO). It combines a 1' x 1' field of view sampled at 0.2 arcsec for its Wide Field Mode (WFM) and a 7.5"x7.5" field of view for its Narrow Field Mode (NFM). Both modes will operate with the improved spatial resolution provided by GALACSI (Ground Atmospheric Layer Adaptive Optics for Spectroscopic Imaging), that will use the VLT deformable secondary mirror and 4 Laser Guide Stars (LGS) foreseen in 2015. MUSE operates in the visible wavelength range (0.465-0.93 μm). A consortium of seven institutes is currently commissioning MUSE in the Very Large Telescope for the Preliminary Acceptance in Chile, scheduled for September, 2014. MUSE is composed of several subsystems which are under the responsibility of each institute. The Fore Optics derotates and anamorphoses the image at the focal plane. A Splitting and Relay Optics feed the 24 identical Integral Field Units (IFU), that are mounted within a large monolithic structure. Each IFU incorporates an image slicer, a fully refractive spectrograph with VPH-grating and a detector system connected to a global vacuum and cryogenic system. During 2012 and 2013, all MUSE subsystems were integrated, aligned and tested to the P.I. institute at Lyon. After successful PAE in September 2013, MUSE instrument was shipped to the Very Large Telescope in Chile where that was aligned and tested in ESO integration hall at Paranal. After, MUSE was directly transported, fully aligned and without any optomechanical dismounting, onto VLT telescope where the first light was overcame the 7th of February, 2014. This paper describes the alignment procedure of the whole MUSE instrument with respect to the Very Large Telescope (VLT). It describes how 6 tons could be move with accuracy better than 0.025mm and less than 0.25 arcmin in order to reach alignment requirements. The success

  14. Problems in the development of autonomous mobile laser systems based on a cw chemical DF laser

    SciTech Connect

    Aleksandrov, B P; Bashkin, A S; Beznozdrev, V N; Parfen'ev, M V; Pirogov, N A; Semenov, S N

    2003-01-31

    The problems involved in designing autonomous mobile laser systems based on high-power cw chemical DF lasers, whose mass and size parameters would make it possible to install them on various vehicles, are discussed. The need for mobility of such lasers necessitates special attention to be paid to the quest for ways and means of reducing the mass and size of the main laser systems. The optimisation of the parameters of such lasers is studied for various methods of scaling their systems. A complex approach to analysis of the optical scheme of the laser system is developed. (special issue devoted to the 80th anniversary of academician n g basov's birth)

  15. Design of laser diode stable output system

    NASA Astrophysics Data System (ADS)

    Liu, Bo; Cao, Rui-ming

    2008-03-01

    High-stability output's system of laser diode is introduced in this paper. The system which is based on the MCU of MSP430 has been designed light power feedback loop and coller of TEC. It includes stable current, protecting circuit, light power feedback loop, temperature controlling, power display and so on. It is also able to control and show the power at the real time. The power could be set by botton too. The software of slow start up, slow close and the protecting relay are adopted by MCU. DRV592 is introduced as PWM driver to control the current of TEC. The duty cycle is generate by MCU. In order to control temperature, it is changed to influence the current of TEC. The power that is sampled by photodiode which is integrated in the laser diode is controlled by the micro-processing. The laser is monitored by voltage control circuit and current control circuit at the real time.

  16. Testing and integrating the laser system of ARGOS: the ground layer adaptive optics for LBT

    NASA Astrophysics Data System (ADS)

    Loose, C.; Rabien, S.; Barl, L.; Borelli, J.; Deysenroth, M.; Gaessler, W.; Gemperlein, H.; Honsberg, M.; Kulas, M.; Lederer, R.; Raab, W.; Rahmer, G.; Ziegleder, J.

    2012-07-01

    The Laser Guide Star facility ARGOS will provide Ground Layer Adaptive Optics to the Large Binocular Telescope (LBT). The system operates three pulsed laser beacons above each of the two primary mirrors, which are Rayleigh scattered in 12km height. This enables correction over a wide field of view, using the adaptive secondary mirror of the LBT. The ARGOS laser system is designed around commercially available, pulsed Nd:YAG lasers working at 532 nm. In preparation for a successful commissioning, it is important to ascertain that the specifications are met for every component of the laser system. The testing of assembled, optical subsystems is likewise necessary. In particular it is required to confirm a high output power, beam quality and pulse stability of the beacons. In a second step, the integrated laser system along with its electronic cabinets are installed on a telescope simulator. This unit is capable of carrying the whole assembly and can be tilted to imitate working conditions at the LBT. It allows alignment and functionality testing of the entire system, ensuring that flexure compensation and system diagnosis work properly in different orientations.

  17. The global light system laser station prototype

    NASA Astrophysics Data System (ADS)

    Hunt, Patrick R.

    We describe the design and fabrication of a prototype Global Light System (GLS) laser station for the JEM-EUSO project. The GLS will consist of a network of ground-based Ultraviolet (UV) light-emitting diodes (LEDs) and steered lasers to monitor and calibrate the cosmic ray detector planned for install on the International Space Station (ISS). The GLS units will generate optical signatures in the atmosphere that are comparable to tracks from cosmic ray extensive air showers (EASs). Unlike an EAS, the number, time, energy, location and direction (for lasers) of GLS events can be specified as JEM-EUSO passes 400 km overhead. Laser tracks from the GLS prototype will be recorded by prototype detectors in ground-to-ground tests. Distant tracks with low angular speed are of particular interest because these are the types of EAS tracks that will be measured by JEM-EUSO. To do these ground-to-ground tests, the prototype detectors will need to measure the laser through the atmosphere at low elevation viewing angles. The beam energy can be adjusted from 1 to 90 mJ to compensate for this additional atmospheric attenuation. The frequency-tripled Nd:YAG laser produces 355 nm (7 ns pulse) light. This wavelength is near the center of the UV EAS fluorescence spectrum. The system is housed in a utility trailer that can be transported by a small truck for domestic campaigns or shipped in an industry standard 20 foot container for global deployment. In operation mode, the laser platform inside the trailer is isolated mechanically to maintain beam pointing accuracy. A retractable two stage steering head can point in any direction above the horizon. A slip ring eliminates cable wrap problems. The GLS prototype will be used to test the EUSO-TA detector and will also be used in preflight tests of the EUSO-balloon payload planned for a super pressure balloon mission.

  18. Neural nets for aligning optical components in harsh environments: Beam smoothing spatial filter as an example

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.; Krasowski, Michael J.

    1991-01-01

    The goal is to develop an approach to automating the alignment and adjustment of optical measurement, visualization, inspection, and control systems. Classical controls, expert systems, and neural networks are three approaches to automating the alignment of an optical system. Neural networks were chosen for this project and the judgements that led to this decision are presented. Neural networks were used to automate the alignment of the ubiquitous laser-beam-smoothing spatial filter. The results and future plans of the project are presented.

  19. Laser-SPS systems analysis and environmental impact assessment

    NASA Technical Reports Server (NTRS)

    Beverly, R. E., III

    1980-01-01

    The systems feasibility and environmental impact of replacing the microwave transmitters on the Satellite Power System with laser transmitters are examined. The lasers suggested are two molecular-gas electric-discharge lasers (EDL's), namely the CO and CO2 lasers. Calculations are made on system efficiency, atmospheric transmission efficiency, and laser beam spreading. It is found that the present satellite concept using lasers is far too inefficient and massive to be economically viable. However, the safety issues associated with laser power transmission appear tractable, and no effects could be identified which present a real danger of serious injury to the environment, although certain phenomena deserve closer scrutiny.

  20. Laser Technology Is Primed for the Classroom.

    ERIC Educational Resources Information Center

    Lytle, Jim

    1986-01-01

    Explains the three characteristics of laser light (monochromatic light, divergence, and coherence), the components of a laser, applications of the laser (alignment, distance measurement, welding/cutting, marking, medical applications), and a complete laser training system appropriate for classroom use. (CT)

  1. COHERENT LASER VISION SYSTEM (CLVS) OPTION PHASE

    SciTech Connect

    Robert Clark

    1999-11-18

    The purpose of this research project was to develop a prototype fiber-optic based Coherent Laser Vision System (CLVS) suitable for DOE's EM Robotic program. The system provides three-dimensional (3D) vision for monitoring situations in which it is necessary to update the dimensional spatial data on the order of once per second. The system has total immunity to ambient lighting conditions.

  2. Kinetic modelling of krypton fluoride laser systems

    SciTech Connect

    Jancaitis, K.S.

    1983-11-01

    A kinetic model has been developed for the KrF* rare gas halide laser system, specifically for electron-beam pumped mixtures of krypton, fluorine, and either helium or argon. The excitation produced in the laser gas by the e-beam was calculated numerically using an algorithm checked by comparing the predicted ionization yields in the pure rare gases with their experimental values. The excitation of the laser media by multi-kilovolt x-rays was also modeled and shown to be similar to that produced by high energy electrons. A system of equations describing the transfer of the initial gas excitation into the laser upper level was assembled using reaction rate constants from both experiment and theory. A one-dimensional treatment of the interaction of the laser radiation with the gas was formulated which considered spontaneous and stimulated emission and absorption. The predictions of this model were in good agreement with the fluorescence signals and gain and absorption measured experimentally.

  3. Underwater modulated pulse laser imaging system

    NASA Astrophysics Data System (ADS)

    O'Connor, Shawn; Mullen, Linda J.; Cochenour, Brandon

    2014-05-01

    The detection and identification of underwater threats in coastal areas are of interest to the Navy. When identifying a potential target, both two-dimensional (amplitude versus position) and three-dimensional (amplitude and range versus position) information are important. Laser imaging in turbid coastal waters makes this task challenging due to absorption and scattering in both the forward and backward directions. Conventional imaging approaches to suppress scatter rely on a pulsed laser and a range-gated receiver or an intensity-modulated continuous wave laser and a coherent RF receiver. The modulated pulsed laser imaging system is a hybrid of these two approaches and uses RF intensity modulation on a short optical pulse. The result is an imaging system capable of simultaneously acquiring high-contrast images along with high-precision unambiguous ranges. A working modulated pulsed laser line scanner was constructed and tested with a custom-built transmitter, a large-bandwidth optical receiver, and a high-speed digitizing oscilloscope. The effectiveness of the modulation to suppress both backscatter and forward scatter, as applied to both magnitude and range images, is discussed.

  4. Automated sample mounting and technical advance alignment system for biological crystallography at a synchrotron source

    SciTech Connect

    Snell, Gyorgy; Cork, Carl; Nordmeyer, Robert; Cornell, Earl; Meigs, George; Yegian, Derek; Jaklevic, Joseph; Jin, Jian; Stevens, Raymond C.; Earnest, Thomas

    2004-01-07

    High-throughput data collection for macromolecular crystallography requires an automated sample mounting system for cryo-protected crystals that functions reliably when integrated into protein-crystallography beamlines at synchrotrons. Rapid mounting and dismounting of the samples increases the efficiency of the crystal screening and data collection processes, where many crystals can be tested for the quality of diffraction. The sample-mounting subsystem has random access to 112 samples, stored under liquid nitrogen. Results of extensive tests regarding the performance and reliability of the system are presented. To further increase throughput, we have also developed a sample transport/storage system based on ''puck-shaped'' cassettes, which can hold sixteen samples each. Seven cassettes fit into a standard dry shipping Dewar. The capabilities of a robotic crystal mounting and alignment system with instrumentation control software and a relational database allows for automated screening and data collection to be developed.

  5. The design of laser scanning galvanometer system

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoling; Zhou, Bin; Xie, Weihao; Zhang, Yuangeng

    2015-02-01

    In this paper, we designed the laser scanning galvanometer system according to our requirements. Based on scanning range of our laser scanning galvanometer system, the design parameters of this system were optimized. During this work, we focused on the design of the f-θ field lens. An optical system of patent lens in the optical manual book, which had three glasses structure, was used in our designs. Combining the aberration theory, the aberration corrections and image quality evaluations were finished using Code V optical design software. An optimum f-θ field lens was designed, which had focal length of 434 mm, pupil diameter of 30 mm, scanning range of 160 mm × 160 mm, and half field angle of 18°×18°. At the last, we studied the influences of temperature changes on our system.

  6. Industrial laser-based coatings removal systems

    NASA Astrophysics Data System (ADS)

    Freiwald, David A.; Peebles, Henry C.; Case, Roger P.

    1998-09-01

    Industrial-cleaning-rate laser systems have been built and tested for removing various types of coatings, such as rad- contaminated coatings, non-rad but hazmat-contaminated coatings (e.g., Pb-based paint), and non-hazardous coatings from various types of substrates such as concrete, metals, and composite materials.

  7. Monolithically integrated absolute frequency comb laser system

    DOEpatents

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  8. 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.

  9. 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.

  10. Systems analysis on laser beamed power

    NASA Technical Reports Server (NTRS)

    Zeiders, Glenn W., Jr.

    1993-01-01

    The NASA SELENE power beaming program is intended to supply cost-effective power to space assets via Earth-based lasers and active optics systems. Key elements of the program are analyzed, the overall effort is reviewed, and recommendations are presented.

  11. T-3 electron-beam-excited laser system

    SciTech Connect

    Klein, R A

    1981-02-01

    A laser system specifically designed to study the kinetics of electron-beam driven systems is described. Details of the system are given along with measurements of the electron-beam uniformity and deposition in the laser medium. Some HF laser results obtained with this system are also given.

  12. Method and system for powering and cooling semiconductor lasers

    SciTech Connect

    Telford, Steven J; Ladran, Anthony S

    2014-02-25

    A semiconductor laser system includes a diode laser tile. The diode laser tile includes a mounting fixture having a first side and a second side opposing the first side and an array of semiconductor laser pumps coupled to the first side of the mounting fixture. The semiconductor laser system also includes an electrical pulse generator thermally coupled to the diode bar and a cooling member thermally coupled to the diode bar and the electrical pulse generator.

  13. Automatic balancing system with laser unit

    NASA Astrophysics Data System (ADS)

    Giers, A.

    1981-01-01

    A balancing plant for miniature rotor gyroscopes was developed, using a pulsed laser for material removal in order to perform the necessary measurements and balancing processes in one single operation. The plant, consisting of five units, is depicted and illustrated by graphs and photographs. The tests were intended to check the machine, to get experimental data, and to investigate the possibilities of this technology. As compared to conventional procedures, this automatic balancing process with laser compensation is rationalized, is faster, is cheaper, and provides a higher balancing quality. The test results confirm the system reliability as well as the process advantages.

  14. Single element laser beam shaper

    DOEpatents

    Zhang, Shukui; Michelle D. Shinn

    2005-09-13

    A single lens laser beam shaper for converting laser beams from any spatial profile to a flat-top or uniform spatial profile. The laser beam shaper includes a lens having two aspheric surfaces. The beam shaper significantly simplifies the overall structure in comparison with conventional 2-element systems and therefore provides great ease in alignment and reduction of cost.

  15. In-plane aligned YBCO film on textured YSZ buffer layer deposited on NiCr alloy tape by laser ablation with only O+ ion beam assistance

    NASA Astrophysics Data System (ADS)

    Tang Huang, Xin; Qing Wang, You; Wang, Qiu Liang; Chen, Qing Ming

    2000-02-01

    High critical current density and in-plane aligned YBa2 Cu3 O7-x (YBCO) film on a textured yttria-stabilized zirconia (YSZ) buffer layer deposited on NiCr alloy (Hastelloy c-275) tape by laser ablation with only O+ ion beam assistance was fabricated. The values of the x-ray phi-scan full width at half-maximum (FWHM) for YSZ(202) and YBCO(103) are 18° and 11°, respectively. The critical current density of YBCO film is 7.9 × 105 A cm-2 at liquid nitrogen temperature and zero field, and its critical temperature is 90 K.

  16. Integration of Aerial and long-range Terrestrial Laser Scanner: alignment strategies and 3D models for landslide/rockslide description

    NASA Astrophysics Data System (ADS)

    Bertacchini, Eleonora; Rivola, Riccardo; Castagnetti, Cristina; Capra, Alessandro; Parmeggiani, Erika

    2013-04-01

    The purpose of this work is to integrate airborne and long-range (up to some kilometers) terrestrial laser scanning data in order to obtain a good and reliable description of the geomorphology of unstable slopes. 3D models derived from the integrated point clouds can be particularly useful to study and analyze complex morphology, vertical walls of rockslides and surfaces with sparse vegetation. Terrestrial Laser Scanning (TLS) and Airborne Laser Scanning (ALS) are very efficient techniques for characterizing the morphostructure of slopes; although both techniques individually show some limits, their integration can overcome these limits. For example, for vertical walls of rock, the TLS could be recommended because of its "frontal" point of view, that permits a description of vertical walls with a higher point density than ALS can reach. On the other hand, the power of the ALS methodology is highlighted when a large and flat area is involved and/or when a lot of vegetation covers the area. The ALS can easily reach the ground with respect to TLS due to its vertical position of measurement and this allows a more reliable result even if the last generation of terrestrial laser scanners has the skill to penetrate inside the vegetation thanks to a multi-echo technology. All the problems and difficulties encountered will be fully described. When a reliable description of the morphology is requested and involved distances are of some kilometers, the alignment strategies, the point cloud management and filtering, along with the DTM generation are crucial aspects that cannot be underestimate. Thus, different alignment techniques were examined (ICP - Iterative Closest Point, backsigthing orientation with GPS positioning, alignment with targets or homologous points). Results could be optimized only combining the different alignment approaches. In addition, the DTM generation was deeply analyzed, comparing TIN (Triangular Irregular Network) and grid mesh format, different point

  17. Software for portable laser light show system

    NASA Astrophysics Data System (ADS)

    Buruchin, Dmitrey J.; Leonov, Alexander F.

    1995-04-01

    Portable laser light show system LS-3500-10M is connected to the parallel port of IBM PC/AT compatible computer. Computer performs output of digital control data describing images. Specially designed control device is used to convert digital data coming from parallel port to the analog signal driving scanner. Capabilities of even cost nothing 286 computer are quite enough for laser graphics control. Technology of scanning used in laser graphics system LS-3500-10M essentially differs from widely spread systems based on galvanometers with mobile core or with mobile magnet. Such devices are based on the same principle of work as electrically driven servo-mechanism. As scanner we use elastic system with hydraulic dampen oscillations and opened loop. For most of applications of laser graphics such system provides satisfactory precision and speed of scanning. LS-3500-10M software gives user ability to create on PC and play his own laser graphics demonstrations. It is possible to render recognizable text and pictures using different styles, 3D and abstract animation. All types of demonstrations can be mixed in slide-show. Time synchronization is supported. Software has the following features: (1) Different types of text output. Built-in text editor for typing and editing of textural information. Different fonts can be used to display text. User can create his own fonts using specially developed font editor. (2) Editor of 3D animation with library of predefined shapes. (3) Abstract animation provided by software routines. (4) Support of different graphics files formats (PCX or DXF). Original algorithm of raster image tracing was implemented. (5) Built-in slide-show editor.

  18. Demonstration of high sensitivity laser ranging system

    NASA Technical Reports Server (NTRS)

    Millar, Pamela S.; Christian, Kent D.; Field, Christopher T.

    1994-01-01

    We report on a high sensitivity semiconductor laser ranging system developed for the Gravity and Magnetic Earth Surveyor (GAMES) for measuring variations in the planet's gravity field. The GAMES laser ranging instrument (LRI) consists of a pair of co-orbiting satellites, one which contains the laser transmitter and receiver and one with a passive retro-reflector mounted in an drag-stabilized housing. The LRI will range up to 200 km in space to the retro-reflector satellite. As the spacecraft pair pass over the spatial variations in the gravity field, they experience along-track accelerations which change their relative velocity. These time displaced velocity changes are sensed by the LRI with a resolution of 20-50 microns/sec. In addition, the pair may at any given time be drifting together or apart at a rate of up to 1 m/sec, introducing a Doppler shift into the ranging signals. An AlGaAs laser transmitter intensity modulated at 2 GHz and 10 MHz is used as fine and medium ranging channels. Range is measured by comparing phase difference between the transmit and received signals at each frequency. A separate laser modulated with a digital code, not reported in this paper, will be used for coarse ranging to unambiguously determine the distance up to 200 km.

  19. The study of laser beam riding guided system based on 980nm diode laser

    NASA Astrophysics Data System (ADS)

    Qu, Zhou; Xu, Haifeng; Sui, Xin; Yang, Kun

    2015-10-01

    With the development of science and technology, precision-strike weapons has been considered to be important for winning victory in military field. Laser guidance is a major method to execute precision-strike in modern warfare. At present, the problems of primary stage of Laser guidance has been solved with endeavors of countries. Several technical aspects of laser-beam riding guided system have been mature, such as atmosphere penetration of laser beam, clutter inhibition on ground, laser irradiator, encoding and decoding of laser beam. Further, laser beam quality, equal output power and atmospheric transmission properties are qualified for warfare situation. Riding guidance instrument is a crucial element of Laser-beam riding guided system, and is also a vital element of airborne, vehicle-mounted and individual weapon. The optical system mainly consist of sighting module and laser-beam guided module. Photoelectric detector is the most important sensing device of seeker, and also the key to acquire the coordinate information of target space. Currently, in consideration of the 1.06 u m of wavelength applied in all the semi-active laser guided weapons systems, lithium drifting silicon photodiode which is sensitive to 1.06 u m of wavelength is used in photoelectric detector. Compared to Solid and gas laser, diode laser has many merits such as small volume, simple construction, light weight, long life, low lost and easy modulation. This article introduced the composition and operating principle of Laser-beam riding guided system based on 980 nm diode laser, and made a analysis of key technology; for instance, laser irradiator, modulating disk of component, laser zooming system. Through the use of laser diode, Laser-beam riding guided system is likely to have smaller shape and very light.

  20. Spaceborne CO2 laser communications systems

    NASA Technical Reports Server (NTRS)

    Mcelroy, J. H.; Mcavoy, N.; Johnson, E. H.; Goodwin, F. E.; Peyton, B. J.

    1975-01-01

    Projections of the growth of earth-sensing systems for the latter half of the 1980's show a data transmission requirement of 300 Mbps and above. Mission constraints and objectives lead to the conclusion that the most efficient technique to return the data from the sensing satellite to a ground station is through a geosynchronous data relay satellite. Of the two links that are involved (sensing satellite to relay satellite and relay satellite to ground), a laser system is most attractive for the space-to-space link. The development of CO2 laser systems for space-to-space applications is discussed with the completion of a 300 Mpbs data relay receiver and its modification into a transceiver. The technology and state-of-the-art of such systems are described in detail.

  1. Wavelength stabilization of high power laser systems using volume holographic gratings

    NASA Astrophysics Data System (ADS)

    Negoita, Viorel C.; Li, Yufeng; Barnowski, Tobias; Jiang, John; An, Haiyan; Roff, Robert; Shih, Ming; Vethake, Thilo; Gottwald, Tina; Schad, Sven; Treusch, Georg

    2014-03-01

    We present our latest experimental results in wavelength stabilization of high power laser diode systems by using Volume Holographic (Bragg) Gratings. Such systems are used as optical pumps to increase the efficiency and brightness of Thin Disk Lasers. To achieve a wide locking range from threshold until maximum operation current (for example from 30A to 250A), careful control of laser system alignment is necessary to ensure effective feedback and locking, without using strong gratings which could reduce laser efficiency. For this purpose, we use wavefront correction optics to compensate for laser bar smile and Fast Axis Collimation pointing errors. We reduce the pointing errors from ~ 1 mrad to an average under 0.1 mrad across the bar and across the entire stack. Time resolved spectra are used to investigate the dynamic locking behavior with the goal of achieving a locking speed comparable to the rise time of the current (100 μs). Experimental results for multi-kW laser systems are presented, both in CW and soft pulsed operation modes.

  2. Design and implementation of a system for laser assisted milling of advanced materials

    NASA Astrophysics Data System (ADS)

    Wu, Xuefeng; Feng, Gaocheng; Liu, Xianli

    2016-04-01

    Laser assisted machining is an effective method to machine advanced materials with the added benefits of longer tool life and increased material removal rates. While extensive studies have investigated the machining properties for laser assisted milling(LAML), few attempts have been made to extend LAML to machining parts with complex geometric features. A methodology for continuous path machining for LAML is developed by integration of a rotary and movable table into an ordinary milling machine with a laser beam system. The machining strategy and processing path are investigated to determine alignment of the machining path with the laser spot. In order to keep the material removal temperatures above the softening temperature of silicon nitride, the transformation is coordinated and the temperature interpolated, establishing a transient thermal model. The temperatures of the laser center and cutting zone are also carefully controlled to achieve optimal machining results and avoid thermal damage. These experiments indicate that the system results in no surface damage as well as good surface roughness, validating the application of this machining strategy and thermal model in the development of a new LAML system for continuous path processing of silicon nitride. The proposed approach can be easily applied in LAML system to achieve continuous processing and improve efficiency in laser assisted machining.

  3. Magnetic alignment of the Tara tandem mirror

    SciTech Connect

    Post, R.S.; Coleman, J.W.; Irby, J.H.; Olmstead, M.M.; Torti, R.P.

    1985-06-01

    Techniques developed for the alignment of high-energy accelerators have been applied to the alignment of the Tara tandem mirror magnetic confinement device. Tools used were: a transit/laser surveyor's system for establishing an invariant reference; optical scattering from ferromagnetic crystallites for establishing magnetic centers in the quadrupole anchor/transition modules; an electron-optical circle-generating wand for alignment of the solenoidal plug and central cell modules; and four differently configured electron emissive probes, including a 40-beam flux mapping e gun, for testing the alignment of the coils under vacuum. Procedures are outlined, and results are given which show that the magnetic axes of the individual coils in the Tara set have been made colinear with each other and with the reference to within +- 1.0 mm over the length of the machine between the anchor midplanes.

  4. Remote measurement of wind speed by laser Doppler systems.

    PubMed

    Hughes, A J; Pike, E R

    1973-03-01

    Several types of laser Doppler velocimeter are considered for remote measurement of wind velocity. Particular attention is given to the range dependence of the mean power SNR when scattering is from natural aerosols. Numerical estimates for two systems are presented, indicating that CO(2) laser systems have considerably greater sensitivity than visible laser systems at ranges greater than a few meters.

  5. 21 CFR 884.6200 - Assisted reproduction laser system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Assisted reproduction laser system. 884.6200... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a...

  6. 21 CFR 884.6200 - Assisted reproduction laser system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Assisted reproduction laser system. 884.6200... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a...

  7. 21 CFR 884.6200 - Assisted reproduction laser system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Assisted reproduction laser system. 884.6200... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a...

  8. 21 CFR 884.6200 - Assisted reproduction laser system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Assisted reproduction laser system. 884.6200... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a...

  9. 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.

  10. 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.

  11. Aligning new interventions with developing country health systems: Target product profiles, presentation, and clinical trial design

    PubMed Central

    Brooks, Alan; Nunes, Julia K.; Garnett, Andrew; Biellik, Robin; Leboulleux, Didier; Birkett, Ashley J.; Loucq, Christian

    2012-01-01

    Many new interventions are being created to address health problems of the developing world. However, many developing countries have fragile health systems and find it difficult to accommodate change. Consequently, it is essential that new interventions are well aligned with health systems and their users. Establishing target product profiles (TPPs) is a critical, early step towards tailoring interventions to suit both of these constituencies. Specific analyses can help identify and establish relevant TPP criteria such as optimal formulation, presentation and packaging. Clinical trials for a new intervention should be designed to address both TPP-specific questions and anticipated use of the intervention in target countries. Examples are provided from research on malaria vaccines that are also applicable to other new public health interventions. PMID:22783872

  12. Rigorous method for compensation selection and alignment of microlithographic optical systems

    SciTech Connect

    Chapman, H.N.; Sweeney, D.W.

    1998-03-25

    The assembly of an optical system requires the correction of aberrations in the entire imaging field by making selected rigid-body motions of the optical elements. We present a rigorous method for determining which adjustment motions, called compensators, to use for alignment. These compensators are found by employing techniques from linear algebra that choose the most independent vectors from a set which are interdependent. The method finds the smallest number of compensators to correct for misalignments of a given magnitude. As an example the method is applied to a four-mirror scanning ring-field EUV lithography system. It is shown that out of 32 degrees of freedom in the configuration of the optical elements, only eight compensators are required on the optics. By adjusting these compensators a misaligned configuration giving a 30 {lambda} wavefront error can be assembled to {lambda}/50 in the absence of measurement noise.

  13. Observability analysis of inertial navigation systems during in-flight alignment

    NASA Technical Reports Server (NTRS)

    Bar-Itzhack, I. Y.; Goshen-Meskin, D.

    1988-01-01

    In this work the observability of an Inertial Navigation System (INS) during In-Flight Alignment (IFA) is investigated. A systematic approach to the observability analysis of a piece-wise constant system is presented and its use is justified mathematically. As a tool for the investigation a Stepped Observability Matrix (SOM) is constructed and a corresponding Stepped Space is defined. The INS error model is transformed into the Stepped Space during a specially chosen IFA trajectory and a full observability is carried out. The results of the mathematical analysis are checked against the results of covariance simulation and a full agreement is found between the two. Finally, the practical implications of this analysis are outlined.

  14. Commercialization plan laser-based decoating systems

    SciTech Connect

    Freiwald, J.; Freiwald, D.A.

    1998-01-01

    F2 Associates Inc. (F2) is a small, high-technology firm focused on developing and commercializing environmentally friendly laser ablation systems for industrial-rate removal of surface coatings from metals, concrete, and delicate substrates such as composites. F2 has a contract with the US Department of Energy Federal Energy Technology Center (FETC) to develop and test a laser-based technology for removing contaminated paint and other contaminants from concrete and metal surfaces. Task 4.1 in Phase 2 of the Statement of Work for this DOE contract requires that F2 ``document its plans for commercializing and marketing the stationary laser ablation system. This document shall include a discussion of prospects for commercial customers and partners and may require periodic update to reflect changing strategy. This document shall be submitted to the DOE for review.`` This report is being prepared and submitted in fulfillment of that requirement. This report describes the laser-based technology for cleaning and coatings removal, the types of laser-based systems that have been developed by F2 based on this technology, and the various markets that are emerging for this technology. F2`s commercialization and marketing plans are described, including how F2`s organization is structured to meet the needs of technology commercialization, F2`s strategy and marketing approach, and the necessary steps to receive certification for removing paint from aircraft and DOE certification for D and D applications. The future use of the equipment built for the DOE contract is also discussed.

  15. Environmental constraints shaping constituent order in emerging communication systems: Structural iconicity, interactive alignment and conventionalization.

    PubMed

    Christensen, Peer; Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    Where does linguistic structure come from? Recent gesture elicitation studies have indicated that constituent order (corresponding to for instance subject-verb-object, or SVO in English) may be heavily influenced by human cognitive biases constraining gesture production and transmission. Here we explore the alternative hypothesis that syntactic patterns are motivated by multiple environmental and social-interactional constraints that are external to the cognitive domain. In three experiments, we systematically investigate different motivations for structure in the gestural communication of simple transitive events. The first experiment indicates that, if participants communicate about different types of events, manipulation events (e.g. someone throwing a cake) and construction events (e.g. someone baking a cake), they spontaneously and systematically produce different constituent orders, SOV and SVO respectively, thus following the principle of structural iconicity. The second experiment shows that participants' choice of constituent order is also reliably influenced by social-interactional forces of interactive alignment, that is, the tendency to re-use an interlocutor's previous choice of constituent order, thus potentially overriding affordances for iconicity. Lastly, the third experiment finds that the relative frequency distribution of referent event types motivates the stabilization and conventionalization of a single constituent order for the communication of different types of events. Together, our results demonstrate that constituent order in emerging gestural communication systems is shaped and stabilized in response to multiple external environmental and social factors: structural iconicity, interactive alignment and distributional frequency. PMID:26402649

  16. Environmental constraints shaping constituent order in emerging communication systems: Structural iconicity, interactive alignment and conventionalization.

    PubMed

    Christensen, Peer; Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    Where does linguistic structure come from? Recent gesture elicitation studies have indicated that constituent order (corresponding to for instance subject-verb-object, or SVO in English) may be heavily influenced by human cognitive biases constraining gesture production and transmission. Here we explore the alternative hypothesis that syntactic patterns are motivated by multiple environmental and social-interactional constraints that are external to the cognitive domain. In three experiments, we systematically investigate different motivations for structure in the gestural communication of simple transitive events. The first experiment indicates that, if participants communicate about different types of events, manipulation events (e.g. someone throwing a cake) and construction events (e.g. someone baking a cake), they spontaneously and systematically produce different constituent orders, SOV and SVO respectively, thus following the principle of structural iconicity. The second experiment shows that participants' choice of constituent order is also reliably influenced by social-interactional forces of interactive alignment, that is, the tendency to re-use an interlocutor's previous choice of constituent order, thus potentially overriding affordances for iconicity. Lastly, the third experiment finds that the relative frequency distribution of referent event types motivates the stabilization and conventionalization of a single constituent order for the communication of different types of events. Together, our results demonstrate that constituent order in emerging gestural communication systems is shaped and stabilized in response to multiple external environmental and social factors: structural iconicity, interactive alignment and distributional frequency.

  17. Performance results on the laser portion of the Keck laser guide star system

    SciTech Connect

    Cooke, J B; Danforth, P M; Erbert, G V; Feldman, M; Friedman, H W; Gavel, D T; Jenkins, S L; Jones, H E; Kanz, V K; Kuklo, T; Newman, M J; Pierce, E L; Presta, R W; Salmon, J T; Thompson, G R; Wong, N J

    1998-09-29

    The Laser Guide Star (LGS) system for the Keck II, 10 m telescope consists of two separate but interconnected systems, the laser and the adaptive optics bench. The laser portion of the LGSl is a set of five frequency doubled YAG lasers pumping a master oscillator-power amplifier dye chain to produce up to 30 W of 589 p at 26 kHz of tuned light. Presently the laser system has been set up at the Keck facility in Waimea, HI and is undergoing test and evaluation. When it will be set up on the Keck II telescope, the pump lasers, dye master oscillator and associated control equipment will be located on the dome floor and the dye laser amplifiers, beam control system and diagnostics will be mounted directly on the telescope as shown in Fig. 1, Extensive use of fiber optics for both transmission of the oscillator pulse and the pump laser light has been used.

  18. Optical scanning system for laser velocimeter

    NASA Technical Reports Server (NTRS)

    Rhodes, D. B.

    1977-01-01

    An optical system was developed to provide fast incremental scanning of a backscattered laser velocimeter focus point over a 36-cm distance. The system is used to measure flow velocities at 16 positions along its optical axis and to scan these 16 positions up to 30 times a second. Dwell time at each location is approximately 2 milliseconds. Sample volumes typically are 0.2 mm in diameter by 1.4 cm in length. The optical scanning system consists of a wheel containing plane parallel quartz windows of various thicknesses. The laser velocimeter beams are imaged to a primary focus within the dead airspace of an optical cell. The beams emerging from the cell pass through the windows of the scanning wheel. The refraction of the beams passing through the windows causes an apparent shift of the focus within the optical cell and hence in the test zone. Light scattered from the secondary focus within the test zone is concurrently collected and reimaged through the same optical path which originally projected the primary focus. The reimaged backscattered light containing the velocity information is then collected and focused onto a photomultiplier detector system to complete the scanned laser velocimeter optical system.

  19. Three-component laser anemometer measurement systems

    NASA Technical Reports Server (NTRS)

    Goldman, Louis J.

    1991-01-01

    A brief overview of the different laser anemometer (LA) optical designs available is presented. Then, the LA techniques that can be used to design a three-component measurement system for annular geometries are described. Some of the facility design considerations unique to these LA systems are also addressed. Following this, the facilities and the LA systems that were used to successfully measure the three components of velocity in the blading of annular-flow machines are reviewed. Finally, possible LA system enhancements and future research directions are presented.

  20. Precision alignment device

    DOEpatents

    Jones, Nelson E.

    1990-01-01

    Apparatus for providing automatic alignment of beam devices having an associated structure for directing, collimating, focusing, reflecting, or otherwise modifying the main beam. A reference laser is attached to the structure enclosing the main beam producing apparatus and produces a reference beam substantially parallel to the main beam. Detector modules containing optical switching devices and optical detectors are positioned in the path of the reference beam and are effective to produce an electrical output indicative of the alignment of the main beam. This electrical output drives servomotor operated adjustment screws to adjust the position of elements of the structure associated with the main beam to maintain alignment of the main beam.

  1. Precision alignment device

    DOEpatents

    Jones, N.E.

    1988-03-10

    Apparatus for providing automatic alignment of beam devices having an associated structure for directing, collimating, focusing, reflecting, or otherwise modifying the main beam. A reference laser is attached to the structure enclosing the main beam producing apparatus and produces a reference beam substantially parallel to the main beam. Detector modules containing optical switching devices and optical detectors are positioned in the path of the reference beam and are effective to produce an electrical output indicative of the alignment of the main beam. This electrical output drives servomotor operated adjustment screws to adjust the position of elements of the structure associated with the main beam to maintain alignment of the main beam. 5 figs.

  2. Laser safety and hazard analysis for the temperature stabilized BSLT ARES laser system.

    SciTech Connect

    Augustoni, Arnold L.

    2003-08-01

    A laser safety and hazard analysis was performed for the temperature stabilized Big Sky Laser Technology (BSLT) laser central to the ARES system based on the 2000 version of the American National Standards Institute's (ANSI) Standard Z136.1, for Safe Use of Lasers and the 2000 version of the ANSI Standard Z136.6, for Safe Use of Lasers Outdoors. As a result of temperature stabilization of the BSLT laser the operating parameters of the laser had changed requiring a hazard analysis based on the new operating conditions. The ARES laser system is a Van/Truck based mobile platform, which is used to perform laser interaction experiments and tests at various national test sites.

  3. Breakup of the aligned H2 molecule by xuv laser pulses: A time-dependent treatment in prolate spheroidal coordinates

    NASA Astrophysics Data System (ADS)

    Guan, Xiaoxu; Bartschat, Klaus; Schneider, Barry I.

    2011-04-01

    We have carried out calculations of the triple-differential cross section for one-photon double ionization of molecular hydrogen for a central photon energy of 75 eV, using a fully ab initio, nonperturbative approach to solve the time-dependent Schrödinger equation in prolate spheroidal coordinates. The spatial coordinates ξ and η are discretized in a finite-element discrete-variable representation. The wave packet of the laser-driven two-electron system is propagated in time through an effective short iterative Lanczos method to simulate the double ionization of the hydrogen molecule. For both symmetric and asymmetric energy sharing, the present results agree to a satisfactory level with most earlier predictions for the absolute magnitude and the shape of the angular distributions. A notable exception, however, concerns the predictions of the recent time-independent calculations based on the exterior complex scaling method in prolate spheroidal coordinates [L. Tao , Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.82.023423 82, 023423 (2010)]. Extensive tests of the numerical implementation were performed, including the effect of truncating the Neumann expansion for the dielectronic interaction on the description of the initial bound state and the predicted cross sections. We observe that the dominant escape mode of the two photoelectrons depends dramatically on the energy sharing. In the parallel geometry, when the ejected electrons are collected along the direction of the laser polarization axis, back-to-back escape is the dominant channel for strongly asymmetric energy sharing, while it is completely forbidden if the two electrons share the excess energy equally.

  4. Genetic algorithm based fast alignment method for strap-down inertial navigation system with large azimuth misalignment.

    PubMed

    He, Hongyang; Xu, Jiangning; Qin, Fangjun; Li, Feng

    2015-11-01

    In order to shorten the alignment time and eliminate the small initial misalignment limit for compass alignment of strap-down inertial navigation system (SINS), which is sometimes not easy to satisfy when the ship is moored or anchored, an optimal model based time-varying parameter compass alignment algorithm is proposed in this paper. The contributions of the work presented here are twofold. First, the optimization of compass alignment parameters, which involves a lot of trial-and-error traditionally, is achieved based on genetic algorithm. On this basis, second, the optimal parameter varying model is established by least-square polynomial fitting. Experiments are performed with a navigational grade fiber optical gyroscope SINS, which validate the efficiency of the proposed method. PMID:26628165

  5. Genetic algorithm based fast alignment method for strap-down inertial navigation system with large azimuth misalignment

    NASA Astrophysics Data System (ADS)

    He, Hongyang; Xu, Jiangning; Qin, Fangjun; Li, Feng

    2015-11-01

    In order to shorten the alignment time and eliminate the small initial misalignment limit for compass alignment of strap-down inertial navigation system (SINS), which is sometimes not easy to satisfy when the ship is moored or anchored, an optimal model based time-varying parameter compass alignment algorithm is proposed in this paper. The contributions of the work presented here are twofold. First, the optimization of compass alignment parameters, which involves a lot of trial-and-error traditionally, is achieved based on genetic algorithm. On this basis, second, the optimal parameter varying model is established by least-square polynomial fitting. Experiments are performed with a navigational grade fiber optical gyroscope SINS, which validate the efficiency of the proposed method.

  6. Spin-Orbit Alignment of Exoplanet Systems: Ensemble Analysis Using Asteroseismology

    NASA Astrophysics Data System (ADS)

    Campante, T. L.; Lund, M. N.; Kuszlewicz, J. S.; Davies, G. R.; Chaplin, W. J.; Albrecht, S.; Winn, J. N.; Bedding, T. R.; Benomar, O.; Bossini, D.; Handberg, R.; Santos, A. R. G.; Van Eylen, V.; Basu, S.; Christensen-Dalsgaard, J.; Elsworth, Y. P.; Hekker, S.; Hirano, T.; Huber, D.; Karoff, C.; Kjeldsen, H.; Lundkvist, M. S.; North, T. S. H.; Silva Aguirre, V.; Stello, D.; White, T. R.

    2016-03-01

    The angle ψ between a planet’s orbital axis and the spin axis of its parent star is an important diagnostic of planet formation, migration, and tidal evolution. We seek empirical constraints on ψ by measuring the stellar inclination is via asteroseismology for an ensemble of 25 solar-type hosts observed with NASA’s Kepler satellite. Our results for is are consistent with alignment at the 2σ level for all stars in the sample, meaning that the system surrounding the red-giant star Kepler-56 remains as the only unambiguous misaligned multiple-planet system detected to date. The availability of a measurement of the projected spin-orbit angle λ for two of the systems allows us to estimate ψ. We find that the orbit of the hot Jupiter HAT-P-7b is likely to be retrograde (\\psi =116\\buildrel{\\circ}\\over{.} {4}-14.7+30.2), whereas that of Kepler-25c seems to be well aligned with the stellar spin axis (\\psi =12\\buildrel{\\circ}\\over{.} {6}-11.0+6.7). While the latter result is in apparent contradiction with a statement made previously in the literature that the multi-transiting system Kepler-25 is misaligned, we show that the results are consistent, given the large associated uncertainties. Finally, we perform a hierarchical Bayesian analysis based on the asteroseismic sample in order to recover the underlying distribution of ψ. The ensemble analysis suggests that the directions of the stellar spin and planetary orbital axes are correlated, as conveyed by a tendency of the host stars to display large values of inclination.

  7. Terminator field-aligned current system: A new finding from model-assimilated data set (MADS)

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Schunk, R. W.; Scherliess, L.; Sojka, J. J.; Gardner, L. C.; Eccles, J. V.; Rice, D.

    2013-12-01

    Physics-based data assimilation models have been recognized by the space science community as the most accurate approach to specify and forecast the space weather of the solar-terrestrial environment. The model-assimilated data sets (MADS) produced by these models constitute an internally consistent time series of global three-dimensional fields whose accuracy can be estimated. Because of its internal consistency of physics and completeness of descriptions on the status of global systems, the MADS has also been a powerful tool to identify the systematic errors in measurements, reveal the missing physics in physical models, and discover the important dynamical physical processes that are inadequately observed or missed by measurements due to observational limitations. In the past years, we developed a data assimilation model for the high-latitude ionospheric plasma dynamics and electrodynamics. With a set of physical models, an ensemble Kalman filter, and the ingestion of data from multiple observations, the data assimilation model can produce a self-consistent time-series of the complete descriptions of the global high-latitude ionosphere, which includes the convection electric field, horizontal and field-aligned currents, conductivity, as well as 3-D plasma densities and temperatures, In this presentation, we will show a new field-aligned current system discovered from the analysis of the MADS produced by our data assimilation model. This new current system appears and develops near the ionospheric terminator. The dynamical features of this current system will be described and its connection to the active role of the ionosphere in the M-I coupling will be discussed.

  8. 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.

  9. TIR-1 carbon dioxide laser system for fusion

    NASA Astrophysics Data System (ADS)

    Adamovich, V. A.; Anisimov, V. N.; Afonin, E. A.; Baranov, V. Iu.; Borzenko, V. L.; Kozochkin, S. M.; Maliuta, D. D.; Satov, Iu. A.; Sebrant, A. Iu.; Smakovski, Iu. B.

    1980-03-01

    The paper examines the TIR-1 carbon dioxide laser system for fusion. The current efforts are concentrated on (1) the microsecond laser pulse plasma heating in solenoids and theta pinches, and (2) nanosecond CO2 laser utilization for inertial confinement fusion. The TIR-1 system was designed to develop nanosecond CO2 laser technology and to study laser-target interaction at 10 microns. This system consists of an oscillator-preamplifier that produces about 1-nsec laser pulse with an energy contrast ratio of 1 million, a large triple-pass amplifier, and a target chamber with diagnostic equipment.

  10. Laser Safety and Hazard Analysis for the Trailer (B70) Based AURA Laser System

    SciTech Connect

    AUGUSTONI, ARNOLD L.

    2003-01-01

    A laser safety and hazard analysis was performed for the AURA laser system based on the 2000 version of the American National Standards Institute's (ANSI) Standard Z136.1, for ''Safe Use of Lasers'' and the 2000 version of the ANSI Standard Z136.6, for ''Safe Use of Lasers Outdoors''. The trailer based AURA laser system is a mobile platform, which is used to perform laser interaction experiments and tests at various national test sites. The trailer (B70) based AURA laser system is generally operated on the United State Air Force Starfire Optical Range (SOR) at Kirtland Air Force Base (KAFB), New Mexico. The laser is used to perform laser interaction testing inside the laser trailer as well as outside the trailer at target sites located at various distances from the exit telescope. In order to protect personnel, who work inside the Nominal Hazard Zone (NHZ), from hazardous laser emission exposures it was necessary to determine the Maximum Permissible Exposure (MPE) for each laser wavelength (wavelength bands) and calculate the appropriate minimum Optical Density (OD{sub min}) of the laser safety eyewear used by authorized personnel and the Nominal Ocular Hazard Distance (NOHD) to protect unauthorized personnel who may have violated the boundaries of the control area and enter into the laser's NHZ.

  11. ANALYSIS OF SPIN-ORBIT ALIGNMENT IN THE WASP-32, WASP-38, AND HAT-P-27/WASP-40 SYSTEMS

    SciTech Connect

    Brown, D. J. A.; Collier Cameron, A.; Enoch, B.; Miller, G. R. M.; Diaz, R. F.; Doyle, A. P.; Smalley, B.; Anderson, D. R.; Hellier, C.; Maxted, P. F. L.; Gillon, M.; Lendl, M.; Triaud, A. H. M. J.; Queloz, D.; Pollacco, D.; Boisse, I.; Hebrard, G.

    2012-12-01

    We present measurements of the spin-orbit alignment angle, {lambda}, for the hot Jupiter systems WASP-32, WASP-38, and HAT-P-27/WASP-40, based on data obtained using the HARPS spectrograph. We analyze the Rossiter-McLaughlin effect for all three systems and also carry out Doppler tomography for WASP-32 and WASP-38. We find that WASP-32 (T {sub eff} = 6140{sup +90} {sub -100} K) is aligned, with an alignment angle of {lambda} = 10.{sup 0}5{sup +6.4} {sub -6.5} obtained through tomography, and that WASP-38 (T {sub eff} = 6180{sup +40} {sub -60} K) is also aligned, with tomographic analysis yielding {lambda} = 7.{sup 0}5{sup +4.7} {sub -6.1}. The latter result provides an order-of-magnitude improvement in the uncertainty in {lambda} compared to the previous analysis of Simpson et al. We are only able to loosely constrain the angle for HAT-P-27/WASP-40 (T{sub eff} = 5190{sup +160} {sub -170} K) to {lambda} = 24.{sup 0}2{sup +76.0}{sub -44.5}, owing to the poor signal-to-noise ratio of our data. We consider this result a non-detection under a slightly updated version of the alignment test of Brown et al. We place our results in the context of the full sample of spin-orbit alignment measurements, finding that they provide further support for previously established trends.

  12. Linkage Of Laser And Handling Systems In Multi Station Operation

    NASA Astrophysics Data System (ADS)

    Petschke, U.; Kramer, R.; Wolff, Udo W.; Beyer, Eckhard

    1989-03-01

    Special requirements are needed for highly flexible, multi station laser processing. Linkage of several lasers with various handling stations causes different kinds of tasks to be solved in the fields of optics, electro mechanics, laser technology and opto electro-nics. A new design for flexible high power CO2 laser beam handling has been developed, including self-checking security systems, laser beam diagnostics, easily adjustable high power beam bending mirrors, high precision motorized mechanics and computer controlled user guidance.

  13. Development of on-line laser power monitoring system

    NASA Astrophysics Data System (ADS)

    Ding, Chien-Fang; Lee, Meng-Shiou; Li, Kuan-Ming

    2016-03-01

    Since the laser was invented, laser has been applied in many fields such as material processing, communication, measurement, biomedical engineering, defense industries and etc. Laser power is an important parameter in laser material processing, i.e. laser cutting, and laser drilling. However, the laser power is easily affected by the environment temperature, we tend to monitor the laser power status, ensuring there is an effective material processing. Besides, the response time of current laser power meters is too long, they cannot measure laser power accurately in a short time. To be more precisely, we can know the status of laser power and help us to achieve an effective material processing at the same time. To monitor the laser power, this study utilize a CMOS (Complementary metal-oxide-semiconductor) camera to develop an on-line laser power monitoring system. The CMOS camera captures images of incident laser beam after it is split and attenuated by beam splitter and neutral density filter. By comparing the average brightness of the beam spots and measurement results from laser power meter, laser power can be estimated. Under continuous measuring mode, the average measuring error is about 3%, and the response time is at least 3.6 second shorter than thermopile power meters; under trigger measuring mode which enables the CMOS camera to synchronize with intermittent laser output, the average measuring error is less than 3%, and the shortest response time is 20 millisecond.

  14. High power laser workover and completion tools and systems

    SciTech Connect

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2014-10-28

    Workover and completion systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser workover and completion of a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform laser workover and completion operations in such boreholes deep within the earth.

  15. Laser beam riding guided system principle and design research

    NASA Astrophysics Data System (ADS)

    Qu, Zhou; Jin, Yi; Xu, Zhou; Xing, Hao

    2016-01-01

    With the development of science and technology, precision-strike weapons has been considered to be important for winning victory in military field. Laser guidance is a major method to execute precision-strike in modern warfare. At present, the problems of primary stage of Laser guidance has been solved with endeavors of countries. Several technical aspects of laser-beam riding guided system have been mature, such as atmosphere penetration of laser beam, clutter inhibition on ground, laser irradiator, encoding and decoding of laser beam. Further, laser beam quality, equal output power and atmospheric transmission properties are qualified for warfare situation. Riding guidance instrument is a crucial element of Laser-beam riding guided system, and is also a vital element of airborne, vehicle-mounted and individual weapon. The optical system mainly consist of sighting module and laser-beam guided module. Photoelectric detector is the most important sensing device of seeker, and also the key to acquire the coordinate information of target space. Currently, in consideration of the 1.06 u m of wavelength applied in all the semi-active laser guided weapons systems, lithium drifting silicon photodiode which is sensitive to 1.06 u m of wavelength is used in photoelectric detector. Compared to Solid and gas laser, diode laser has many merits such as small volume, simple construction, light weight, long life, low lost and easy modulation. This article introduced the composition and operating principle of Laser-beam riding guided system based on 980 nm diode laser, and made a analysis of key technology; for instance, laser irradiator, modulating disk of component, laser zooming system. Through the use of laser diode, Laser-beam riding guided system is likely to have smaller shape and very light.

  16. Optical diagnostics integrated with laser spark delivery system

    DOEpatents

    Yalin, Azer; Willson, Bryan; Defoort, Morgan; Joshi, Sachin; Reynolds, Adam

    2008-09-02

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  17. Girder Alignment Plan

    SciTech Connect

    Wolf, Zackary; Ruland, Robert; LeCocq, Catherine; Lundahl, Eric; Levashov, Yurii; Reese, Ed; Rago, Carl; Poling, Ben; Schafer, Donald; Nuhn, Heinz-Dieter; Wienands, Uli; /SLAC

    2010-11-18

    The girders for the LCLS undulator system contain components which must be aligned with high accuracy relative to each other. The alignment is one of the last steps before the girders go into the tunnel, so the alignment must be done efficiently, on a tight schedule. This note documents the alignment plan which includes efficiency and high accuracy. The motivation for girder alignment involves the following considerations. Using beam based alignment, the girder position will be adjusted until the beam goes through the center of the quadrupole and beam finder wire. For the machine to work properly, the undulator axis must be on this line and the center of the undulator beam pipe must be on this line. The physics reasons for the undulator axis and undulator beam pipe axis to be centered on the beam are different, but the alignment tolerance for both are similar. In addition, the beam position monitor must be centered on the beam to preserve its calibration. Thus, the undulator, undulator beam pipe, quadrupole, beam finder wire, and beam position monitor axes must all be aligned to a common line. All relative alignments are equally important, not just, for example, between quadrupole and undulator. We begin by making the common axis the nominal beam axis in the girder coordinate system. All components will be initially aligned to this axis. A more accurate alignment will then position the components relative to each other, without incorporating the girder itself.

  18. New Terminology for the High-Latitude Field-Aligned Current Systems

    NASA Astrophysics Data System (ADS)

    Papitashvili, V.; Weimer, D.

    2003-12-01

    Since pioneering works of Iijima and Potemra in mid-1970s, the lexical meaning of terms Region 1 and Region 2 have formulated a definitive lexicon for describing the field-aligned currents systems linking the outer and inner magnetosphere with both the northern and southern polar ionospheres. However, the Region 0 system remains problematic in its clear detection or definition; at the same time, the NBZ FAC system has been easily accepted for describing of reverse (to R1) currents at the near-pole dayside developed during the northward IMF. The separate IMF B{y}-related FAC configurations were either observed by satellites or reconstructed from ground-based data for the dayside cusp region; multi-sheet current systems were proposed for the nightside polar area. Although it seems that these lexical elements were sufficient in describing various components of the global 3-D FAC systems, a number of recent studies utilized high-precision satellite magnetic field measurements for deriving detailed FAC polar maps as a function of the IMF strength and direction. The basic R1/R2 and NBZ patterns are seen, but the maps show structures that are more complex and evolving as the IMF vector rotates. In addition, a potentially new FAC system is detected from statistical maps for IMF ˜ 0, having the same current directions as NBZ. This system might be considered as a part of the R0 system; from the other hand, what might be considered as a R1 current footprint often wraps around, through noon or midnight, connecting with either R2 or R0 currents (when IMF By is either negative or positive, respectively) without any obvious boundary line. Interestingly, the new statistical maps show features resembling the ``upward current spiral'' and ``downward current spiral'' introduced by Siscoe and Maynard [JGRA, 96, 21,071, 1991] from combining two theoretical models of R1 and R2 currents. These spirals ``rotate'' over the polar cap showing R0, R1, and R2 segments at the corresponding MLT

  19. Laser Docking System Radar flight experiment

    NASA Technical Reports Server (NTRS)

    Erwin, Harry O.

    1986-01-01

    Flight experiments to verify the Laser Docking System Radar are discussed. The docking requirements are summarized, and the breadboarded hardware is described, emphasizing the two major scanning concepts being utilized: a mechanical scanning technique employing galvanometer beamsteerers and an electronic scanning technique using an image dissector. The software simulations used to apply hardware solutions to the docking requirements are briefly discussed, the tracking test bed is described, and the objectives of the flight experiment are reviewed.

  20. Optically pumped isotopic ammonia laser system

    DOEpatents

    Buchwald, Melvin I.; Jones, Claude R.; Nelson, Leonard Y.

    1982-01-01

    An optically pumped isotopic ammonia laser system which is capable of producing a plurality of frequencies in the middle infrared spectral region. Two optical pumping mechanisms are disclosed, i.e., pumping on R(J) and lasing on P(J) in response to enhancement of rotational cascade lasing including stimulated Raman effects, and, pumping on R(J) and lasing on P(J+2). The disclosed apparatus for optical pumping include a hole coupled cavity and a grating coupled cavity.