Science.gov

Sample records for laser alignment system

  1. 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.

  2. Evolution of shiva laser alignment systems

    SciTech Connect

    Boyd, R.D.

    1980-07-01

    The Shiva oscillator pulse is preamplified and divided into twenty beams. Each beam is then amplified, spatially filtered, directed, and focused onto a target a few hundred micrometers in size producing optical intensities up to 10/sup 16/W/cm/sup 2/. The laser was designed and built with three automatic alignment systems: the oscillator alignment system, which aligns each of the laser's three oscillators to a reference beamline; the chain input pointing system, which points each beam into its respective chain; and the chain output pointing, focusing and centering system which points, centers and focuses the beam onto the target. Recently the alignment of the laser's one hundred twenty spatial filter pinholes was also automated. This system uses digitized video images of back-illuminated pinholes and computer analysis to determine current positions. The offset of each current position from a desired center point is then translated into stepper motor commands and the pinhole is moved the proper distance. While motors for one pinhole are moving, the system can digitize, analyze, and send commands to other motors, allowing the system to efficiently align several pinholes in parallel.

  3. 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.

  4. Boresight alignment method for mobile laser scanning systems

    NASA Astrophysics Data System (ADS)

    Rieger, P.; Studnicka, N.; Pfennigbauer, M.; Zach, G.

    2010-06-01

    Mobile laser scanning (MLS) is the latest approach towards fast and cost-efficient acquisition of 3-dimensional spatial data. Accurately evaluating the boresight alignment in MLS systems is an obvious necessity. However, recent systems available on the market may lack of suitable and efficient practical workflows on how to perform this calibration. This paper discusses an innovative method for accurately determining the boresight alignment of MLS systems by employing 3D laser scanners. Scanning objects using a 3D laser scanner operating in a 2D line-scan mode from various different runs and scan directions provides valuable scan data for determining the angular alignment between inertial measurement unit and laser scanner. Field data is presented demonstrating the final accuracy of the calibration and the high quality of the point cloud acquired during an MLS campaign.

  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. High resolution Fresnel zone plate laser alignment system

    SciTech Connect

    Bressler, V.E.; Fischer, G.E.; Ruland, R.E.; Wang, T.

    1992-03-01

    The existing Fresnel zone plate laser alignment system is currently being extended and upgraded for the Final Focus Test Beam (FFTB). Previously, the resolution of this system has been several tens of micrometers. After the upgrade, the resolution will be a few micrometers. Details of the upgrade as well as simulation and experimental results will be presented.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Design and performance of an automated video-based laser beam alignment system

    SciTech Connect

    Rundle, W.J. ); Kartz, M.W. ); Bliss, E.S.; English, R.E. Jr.; Peterson, R.L.; Thompson, G.R.; Uhlich, D.M. )

    1992-07-14

    This paper describes the design and performance of an automated, closed-loop, laser beam alignment system. Its function is to sense a beam alignment error in a laser beam transport system and automatically steer mirrors preceding the sensor location as required to maintain beam alignment. The laser beam is sampled by an optomechanical package which uses video cameras to sense pointing and centering errors. The camera outputs are fed to an image processing module, which includes video digitizers and uses image storage and software to sense the centroid of the image. Signals are sent through a VMEbus to an optical device controller'' (ODC), which drives stepper-motor actuators on mirror mounts preceding the beam-sampling location to return the beam alignment to the prescribed condition. Photodiodes are also used to extend the control bandwidth beyond that which is achievable with video cameras. This system has been operated at LLNL in the Atomic Vapor Laser Isotope Separation (AVLIS) program to maintain the alignment of copper and dye laser beams, the latter to within [plus minus]2 [mu]r in pointing and less than 1 mm in centering. The optomechanical design of the instrumented package, which includes lens, mirror, and video mounts in a rigid housing, the automated control system architecture, and the performance of this equipment is described.

  15. Design and performance of an automated video-based laser beam alignment system

    SciTech Connect

    Rundle, W.J.; Kartz, M.W.; Bliss, E.S.; English, R.E. Jr.; Peterson, R.L.; Thompson, G.R.; Uhlich, D.M.

    1992-07-14

    This paper describes the design and performance of an automated, closed-loop, laser beam alignment system. Its function is to sense a beam alignment error in a laser beam transport system and automatically steer mirrors preceding the sensor location as required to maintain beam alignment. The laser beam is sampled by an optomechanical package which uses video cameras to sense pointing and centering errors. The camera outputs are fed to an image processing module, which includes video digitizers and uses image storage and software to sense the centroid of the image. Signals are sent through a VMEbus to an ``optical device controller`` (ODC), which drives stepper-motor actuators on mirror mounts preceding the beam-sampling location to return the beam alignment to the prescribed condition. Photodiodes are also used to extend the control bandwidth beyond that which is achievable with video cameras. This system has been operated at LLNL in the Atomic Vapor Laser Isotope Separation (AVLIS) program to maintain the alignment of copper and dye laser beams, the latter to within {plus_minus}2 {mu}r in pointing and less than 1 mm in centering. The optomechanical design of the instrumented package, which includes lens, mirror, and video mounts in a rigid housing, the automated control system architecture, and the performance of this equipment is described.

  16. 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.

  17. Optical alignment influenced aberrations in laser beam delivery systems and their correction

    NASA Astrophysics Data System (ADS)

    Scaggs, Michael; Haas, Gil

    2015-03-01

    Industrial high power laser systems are often evaluated based upon spatial profile of the beam before they are brought to focus for processing materials. It is therefore often assumed that if the raw beam profile is good that the focus is equally as good. The possibility of having good optics and poor alignment or bad optics and good alignment and therefore not achieve a good focal spot is quite high due to the fact that a raw beam spatial profile does not manifest third order aberrations. In such instances the focal spot will contain aberrations when there are slightly misaligned, poor quality, high power optics in the system such as a beam expander or eye piece and objective of a 3-axis galvo. Likewise, if the beam itself is not on axis, the third order aberrations of astigmatism and coma are likely to appear but again not be seen in the unfocused beams spatial profile. The third order aberrations of astigmatism, coma and spherical aberration can significantly alter both the size and spatial profile at the focus resulting in out of spec performance. The impact of beam and zoom expanders and their alignment in beam delivery systems is investigated by measuring both the far field unfocused and the far field focus beams using an all passive beam waist analyzer system.

  18. 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.

  19. 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.

  20. Electro-optical systems to accurately align (boresight) laser designator, FLIR, and CCD on the ground before the mission

    NASA Astrophysics Data System (ADS)

    Cabib, Dario; Segal, Alon; Dolev, Jacob

    2008-10-01

    CI Systems has been involved in the development and production of in-flight boresight equipment since 19891,2, by pioneering the field with innovative laser-FLIR and laser-CCD alignment solutions. In addition, over the years we have developed a number of systems for use on the ground to align the various electro-optical instrumentation to a common Line of Sight (LOS) before the mission. This adjustment is very important for the success of the mission: the more accurate the alignment and its retention during the flight, the better the chance of a precise hit. In this paper we describe various systems developed and built at CI for use with EO pods mounted on aircraft, especially UAV's. The most important engineering tasks are design for small size and convenient mechano-optical interfaces for different pods allowing system compactness, low weight and easy operation. Some of the design considerations to meet these challenges will be given here.

  1. 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.

  2. Alignment of a tiled-grating compressor in a high-power chirped-pulse amplification laser system.

    PubMed

    Hornung, Marco; Bödefeld, Ragnar; Siebold, Mathias; Schnepp, Matthias; Hein, Joachim; Sauerbrey, Roland; Kaluza, Malte C

    2007-10-20

    We present a novel technique to align a tiled grating in all five relevant degrees of freedom utilized in the compressor of the high-power chirped-pulse amplification laser system POLARIS at the Institute for Optics and Quantum Electronics, Jena, Germany. With this technique, alignment errors of the two gratings with respect to each other can be detected with an accuracy of 1 microrad for the rotational and 40 nm for the translational degrees of freedom. This is well sufficient to recompress 1030 nm pulses, which were stretched to 2.2 ns before amplification, to their bandwith limit of 150 fs. PMID:17952178

  3. 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.

  4. 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.

  5. Intense laser ionization of transiently aligned CO

    SciTech Connect

    Pinkham, D.; Jones, R.R.

    2005-08-15

    We have measured the ionization rate for CO molecules exposed to intense 30 fsec 780 nm laser pulses as a function of the angle between the molecular and laser polarization axes. Nonionizing, 70 fsec laser pulses are used to coherently prepare the molecules, preferentially aligning them for the strong-field ionization experiments. We find a 2:1 ionization-rate ratio for molecules aligned parallel or perpendicular to the ionizing field.

  6. 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.

  7. MAST YAG Thomson scattering upgrade alignment system

    SciTech Connect

    Figueiredo, J.; Serra, F.; Naylor, G.; Walsh, M.; Dunstan, M.; Scannell, R.

    2010-10-15

    The recent upgrade to the MAST YAG Thomson scattering while enhancing the diagnostic capabilities increased the complexity of the system. There are eight YAG lasers now operational, doubling the number from the previous setup. This means alignment between each laser individually and reference points is essential to guarantee data quality and diagnostic reliability. To address this issue an alignment system was recently installed. It mimics the beams alignment in MAST by sampling 1% of the laser beam that is sent into a telescope which demagnifies by a factor of 8. The demagnified beam is viewed with a CCD camera. By scanning the camera the profile and position of the beams in the scattering zone and in a range of several meters inside MAST can be determined. Therefore alignment is checked along the beam path without having to sample it inside the vessel. The experimental apparatus and test procedures are described.

  8. 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.

  9. 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.

  10. Optical Alignment Device For Laser Communication

    NASA Technical Reports Server (NTRS)

    Casey, William L.

    1988-01-01

    Optical alignment device under development enables continuous tracking and coalignment of two beams of light. Intended primarily for laser-communication station, in which transmitted beam must be aligned with received beam to ensure transmitted beam falls on receiver at other station. Expected to consume less power and be smaller and less complicated than alignment shutter and drive previously used. Prism and filter separate two overlapping collimated light beams of different wavelength or polarization. Coordinates of two beams tracked on charge-coupled device to determine degree of directional misalignment between two beams.

  11. Alignment system for encoders

    NASA Technical Reports Server (NTRS)

    Villani, Daniel D. (Inventor)

    1988-01-01

    An improved encoder alignment system is disclosed which provides an indication of the extent of misalignment and a measure of the rate at which the misalignment may be changing. The invention is adapted for use with a conventional encoder which provides a digital coarse word having at least significant bit and a digital fine word having a least significant bit and a most significant bit. The invention generates the exclusive or of the least significant bit of the coarse digital signal and the least significant bit of the fine digital signal to provide a first signal. The invention then generates the exclusive or of the first signal and the complement of the most significant bit of the fine digital signal to provide an output signal which represents the misalignment of the encoder.

  12. 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.

  13. 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.

  14. Improved docking alignment system

    NASA Technical Reports Server (NTRS)

    Monford, Leo G. (Inventor)

    1988-01-01

    Improved techniques are provided for the alignment of two objects. The present invention is particularly suited for 3-D translation and 3-D rotational alignment of objects in outer space. A camera is affixed to one object, such as a remote manipulator arm of the spacecraft, while the planar reflective surface is affixed to the other object, such as a grapple fixture. A monitor displays in real-time images from the camera such that the monitor displays both the reflected image of the camera and visible marking on the planar reflective surface when the objects are in proper alignment. The monitor may thus be viewed by the operator and the arm manipulated so that the reflective surface is perpendicular to the optical axis of the camera, the roll of the reflective surface is at a selected angle with respect to the camera, and the camera is spaced a pre-selected distance from the reflective surface.

  15. Precision laser aiming system

    SciTech Connect

    Ahrens, Brandon R.; Todd, Steven N.

    2009-04-28

    A precision laser aiming system comprises a disrupter tool, a reflector, and a laser fixture. The disrupter tool, the reflector and the laser fixture are configurable for iterative alignment and aiming toward an explosive device threat. The invention enables a disrupter to be quickly and accurately set up, aligned, and aimed in order to render safe or to disrupt a target from a standoff position.

  16. 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.

  17. 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

  18. Docking alignment system

    NASA Technical Reports Server (NTRS)

    Monford, Leo G. (Inventor)

    1990-01-01

    Improved techniques are provided for alignment of two objects. The present invention is particularly suited for three-dimensional translation and three-dimensional rotational alignment of objects in outer space. A camera 18 is fixedly mounted to one object, such as a remote manipulator arm 10 of the spacecraft, while the planar reflective surface 30 is fixed to the other object, such as a grapple fixture 20. A monitor 50 displays in real-time images from the camera, such that the monitor displays both the reflected image of the camera and visible markings on the planar reflective surface when the objects are in proper alignment. The monitor may thus be viewed by the operator and the arm 10 manipulated so that the reflective surface is perpendicular to the optical axis of the camera, the roll of the reflective surface is at a selected angle with respect to the camera, and the camera is spaced a pre-selected distance from the reflective surface.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Robust optical alignment systems using geometric invariants

    NASA Astrophysics Data System (ADS)

    Ho, Tzung-Hsien; Rzasa, John; Milner, Stuart D.; Davis, Christopher C.

    2007-09-01

    Traditional coarse pointing, acquisition, and tracking (CPAT) systems are pre-calibrated to have the center pixel of the camera aligned to the laser pointing vector and the center pixel is manually moved to the target of interest to complete the alignment process. Such a system has previously demonstrated its capability in aligning with distant targets and the pointing accuracy is on the order of sensor resolution. However, aligning with targets at medium range where the distance between angular sensor and transceiver is not negligible is its Achilles Heel. This limitation can be resolved by imposing constraints, such as the trifocal tensor (TT), which is deduced from the geometrical dependence between cameras and transceivers. Two autonomous CPAT systems are introduced for FSO transceiver alignment in mid- and long-range scenarios. This work focuses on experimental results that validate the pointing performance for targets at different distances, backed up by the theoretical derivations. A mid-range CPAT system, applying a trifocal tensor as its geometric invariant, includes two perspective cameras as sensors to perceive target distances. The long-range CPAT system, applying linear mapping as the invariant, requires only one camera to determine the pointing angle. Calibration procedures for both systems are robust to measurement noise and the resulting system can autonomously point to a target of interest with a high accuracy, which is also on the order of sensor resolution. The results of this work are not only beneficial to the design of CPAT systems for FSO transceiver alignment, but also in new applications such as surveillance and navigation.

  4. Optically Probed Laser-Induced Field-Free Molecular Alignment

    NASA Astrophysics Data System (ADS)

    Faucher, O.; Lavorel, B.; Hertz, E.; Chaussard, F.

    Molecular alignment induced by laser fields has been investigated in research laboratories for over two decades. It led to a better understanding of the fundamental processes at play in the interaction of strong laser fields with molecules, and also provided significant contributions to the fields of high harmonic generation, laser spectroscopy, and laser filamentation. In this chapter, we discuss molecular alignment produced under field-free conditions, as resulting from the interaction of a laser pulse of duration shorter than the rotational period of the molecule. The experimental results presented will be confined to the optically probed alignment of linear as well as asymmetric top molecules. Special care will be taken to describe and compare various optical methods that can be employed to characterize laser-induced molecular alignment. Promising applications of optically probed molecular alignment will be also demonstrated.

  5. Laser induced alignment of molecules dissolved in Helium nanodroplets

    NASA Astrophysics Data System (ADS)

    Stapelfeldt, Henrik

    2013-05-01

    Laser induced alignment, the method to confine the principal axes of molecules along axes fixed in the laboratory frame, is now used in a range of applications in physics and chemistry. With a few exceptions all studies have focused on isolated molecules in the gas phase. In this talk we present experimental studies of laser induced alignment of molecules embedded in the solvent of a superfluid helium nanodroplet. Alignment is conducted in both the adiabatic and the nonadiabtic regime where the alignment pulse is much longer or shorter, respectively, than the rotational period of the molecules. In the nonadiabatic limit, induced by a few-hundred femtosecond long laser pulse, we show that methyliodide molecules reach an alignment maximum 20 ps after the alignment pulse and gradually loose the alignment completely in another 60 ps. This dynamics is completely different from that of isolated methyliodide molecules where alignment occurs in regularly spaced (by 33.3 ps), narrow time windows, termed revivals. Adiabatic alignment, induced by 10 ns laser pulses, resembles the gas phase behavior although the observed degree of alignment falls below that of isolated molecules. Work done in collaboration with Dominik Pentkehner, Department of Chemistry, Aarhus University; Jens Hedegaard Nielsen, Department of Physics, Aarhus University; Alkwin Slenczka, Department of Chemistry, Regensburg University; and Klaus Mølmer, Department of Physics, Aarhus University.

  6. Global Alignment System for Large Genomic Sequencing

    Energy Science and Technology Software Center (ESTSC)

    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.

  7. 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.

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

    DOE PAGESBeta

    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

  9. 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.

  10. 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.

  11. 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

  12. Laser induced alignment of state-selected CH3I.

    PubMed

    He, Lanhai; Bulthuis, Jaap; Luo, Sizuo; Wang, Jia; Lu, Chunjing; Stolte, Steven; Ding, Dajun; Roeterdink, Wim G

    2015-10-01

    Hexapole state selection is used to prepare CH3I molecules in the |JKM〉 = |1±1∓1〉 state. The molecules are aligned in a strong 800 nm laser field, which is linearly polarised perpendicular to the weak static extraction field E of the time of flight setup. The molecules are subsequently ionised by a second time delayed probe laser pulse. It will be shown that in this geometry at high enough laser intensities the Newton sphere has sufficient symmetry to apply the inverse Abel transformation to reconstruct the three dimensional distribution from the projected ion image. The laser induced controllable alignment was found to have the upper and lower extreme values of 〈P2(cos θ)〉 = 0.7 for the aligned molecule and -0.1 for the anti-aligned molecule, coupled to 〈P4(cos θ)〉 between 0.3 and 0.0. The method to extract the alignment parameters 〈P2(cos θ)〉 and 〈P4(cos θ)〉 directly from the velocity map ion images will be discussed. PMID:26314900

  13. 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.

  14. VISA UNDULATOR RE-ALIGNMENT USING AN OPTICAL MONITORING SYSTEM.

    SciTech Connect

    TREMAINE,A.; MUROKH,A.; WANG,X.J.

    2001-01-01

    The VISA experiment is designed to reach and study saturation in a high gain 800nm SASE FEL at the Brookhaven Accelerator Test Facility (ATF). To do this, the undulator must be aligned at first to within 20 {micro}m with use of a laser interferometric system. Once aligned, any small movements from the aligned position will greatly detriment the SASE FEL performance thus making continuous monitoring of the undulator position necessary. This is quite a complicated task since the 4m undulator is made up of four 1m sections enclosed in a vacuum chamber. We have developed an in situ optical system to monitor the undulator position with an accuracy better than 10 {micro}m. In addition, we have demonstrated the accuracy of this system by bringing the grossly misaligned VISA undulator ({approximately} 500 {micro}m in some locations) into alignment and attaining very high gain of the SASE FEL.

  15. 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 disks 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 $33^{\\circ}$ 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 $52^{\\circ}$) and we find that around $20\\%$ of systems have a misalignment angle larger than $78^{\\circ}$, 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 (disk) 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. In-plane laser forming for high precision alignment

    NASA Astrophysics Data System (ADS)

    Folkersma, Ger; Römer, Gert-Willem; Brouwer, Dannis; Veld, Bert Huis in't.

    2014-12-01

    Laser microforming is extensively used to align components with submicrometer accuracy, often after assembly. While laser-bending sheet metal is the most common laser-forming mechanism, the in-plane upsetting mechanism is preferred when a high actuator stiffness is required. A three-bridge planar actuator made out of Invar 36 sheet was used to characterize this mechanism by experiments, finite element method modeling, and a fast-reduced model. The predictions of the thermal models agree well with the temperature measurements, while the final simulated displacement after 15 pulses deviates up to a factor of 2 from the measurement, using standard isotropic hardening models. Furthermore, it was found from the experiments and models that a small bridge width and a large bridge thickness are beneficial to decrease the sensitivity to disturbances in the process. The experiments have shown a step size as small as 0.1 μm, but with a spread of 20%. This spread is attributed to scattering in surface morphology, which affects the absorbed laser power. To decrease the spread and increase the positioning accuracy, an adapted closed-loop learning algorithm is proposed. Simulations using the reduced model showed that 78% of the alignment trials were within the required accuracy of ±0.1 μm.

  2. An Automated Fiber Alignment, Fixing, And Hermetic Sealing System

    NASA Astrophysics Data System (ADS)

    Bargar, Daniel S.

    1989-02-01

    An automated fiber alignment, fixing, and sealing process was developed for optoelectronic devices produced by BT&D Technologies. The products -- transmitters, receivers, etc. -- were developed simultaneously with the process, allowing development of common technologies and submodule "building blocks." This approach has many advantages: sufficient manufacturing volume to justify automation, quick response to new product variations, and uniform quality. This paper describes the development of a patented laser-based manufacturing system for pigtailing optoelectronic devices.

  3. An Automated Fiber Alignment, Fixing, And Hermetic Sealing System

    NASA Astrophysics Data System (ADS)

    Bargar, Daniel S.

    1989-01-01

    An automated fiber alignment, fixing, and sealing process was developed for optoelectronic devices produced by BT&D Technologies. The products -- transmitters, receivers, etc. -- were developed simultaneously with the process, allowing development of common technologies and submodule "building blocks." This approach has many advantages: sufficient manufacturing volume to justify automation, quick response to new product variations, and uniform quality. This paper describes the development of a patented laser-based manufacturing system for pigtailing optoelectronic devices.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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)

  12. 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

  13. Implementation of two-state alignment system into CXrL aligner (Poster Paper)

    NASA Astrophysics Data System (ADS)

    Chen, Guan-Jye; Bodoh, D.; Wallace, John P.; Anderson, Paul D.; Reilly, Michael T.; Nachman, Ramez; Cerrina, Franco

    1992-07-01

    We describe the implementation of the two-state alignment system into the CXrL aligner, which is developed at our Center for X-ray Lithography. The CXrL aligner is designed to expose sub 0.25 μm feature size integrated circuits. The aligner consists of a three-axes two-state alignment system for alignment error detection and a piezo based precision mechanical stage for alignment error correction. The wafer is held by a precision vacuum chuck, while the mask is held by three vacuum suction cups located around the glass ring. In the prototype, the mask to wafer relative positioning is achieved by 3 motorized stages (for gap setting) and 3 piezo-actuators (for lateral alignment). Since the optical system is designed to be located outside of the synchrotron radiation path, alignment can be performed during exposure. We present the results of the alignment system performance, such as noise equivalent displacement and alignment signal response time. An alignment signal repeatibility of much better than 3σ = 0.07μm is achieved. We also briefly describe the future evaluation of the system, such as overlay measurement of the system using verniers and SEM inspection of some specially designed patterns.

  14. 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.

  15. 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

  16. Advanced mask aligner lithography: new illumination system.

    PubMed

    Voelkel, Reinhard; Vogler, Uwe; Bich, Andreas; Pernet, Pascal; Weible, Kenneth J; Hornung, Michael; Zoberbier, Ralph; Cullmann, Elmar; Stuerzebecher, Lorenz; Harzendorf, Torsten; Zeitner, Uwe D

    2010-09-27

    A new illumination system for mask aligner lithography is presented. The illumination system uses two subsequent microlens-based Köhler integrators. The second Köhler integrator is located in the Fourier plane of the first. The new illumination system uncouples the illumination light from the light source and provides excellent uniformity of the light irradiance and the angular spectrum. Spatial filtering allows to freely shape the angular spectrum to minimize diffraction effects in contact and proximity lithography. Telecentric illumination and ability to precisely control the illumination light allows to introduce resolution enhancement technologies (RET) like customized illumination, optical proximity correction (OPC) and source-mask optimization (SMO) in mask aligner lithography. PMID:20940992

  17. 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.

  18. 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.

  19. 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.

  20. System Would Keep Telescope Reflector Segments Aligned

    NASA Technical Reports Server (NTRS)

    Mettler, Edward; Eldred, Daniel B.; Briggs, Hugh C.; Agronin, Michael L.; Kiceniuk, Taras

    1991-01-01

    Proposed actuation system maintains alignments of reflector segments of large telescope. Sensors measure positions and orientations of segments. Figure-control computer calculates orientation and figure of overall reflector surface from sensor data. Responding to computer output, servocontroller for each actuator corrects piston and tilt errors of each segment. Actuators adjust segments in response to sensed positions. Concept applicable to such large segmented space-based reflectors as those used in communication and in collection of solar energy.

  1. Hardware accelerated optical alignment of lasers using beam-specific matched filters.

    PubMed

    Awwal, Abdul A S; Rice, Kenneth L; Taha, Tarek M

    2009-09-20

    Accurate automated alignment of laser beams in the National Ignition Facility (NIF) is essential for achieving extreme temperature and pressure required for inertial confinement fusion. The alignment achieved by the integrated control systems relies on algorithms processing video images to determine the position of the laser beam images in real time. Alignment images that exhibit wide variations in beam quality require a matched-filter algorithm for position detection. One challenge in designing a matched-filter-based algorithm is to construct a filter template that is resilient to variations in imaging conditions while guaranteeing accurate position determination. A second challenge is to process images for thousands of templates in under a second, as may be required in future high-energy laser systems. This paper describes the development of a new analytical template that captures key recurring features present in the beam image to accurately estimate the beam position under good image quality conditions. Depending on the features present in a particular beam, the analytical template allows us to create a highly tailored template containing only those selected features. The second objective is achieved by exploiting the parallelism inherent in the algorithm to accelerate processing using parallel hardware that provides significant performance improvement over conventional processors. In particular, a Xilinx Virtex II Pro field programmable gate array (FPGA) hardware implementation processing 32 templates provided a speed increase of about 253 times over an optimized software implementation running on a 2.2 GHz AMD Opteron core. PMID:19767937

  2. 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.

  3. Theory of x-ray absorption by laser-aligned symmetric-top molecules.

    SciTech Connect

    Buth, C.; Santra, R.; Chemical Sciences and Engineering Division

    2008-01-01

    We devise a theory of x-ray absorption by symmetric-top molecules which are aligned by an intense optical laser. Initially, the density matrix of the system is composed of the electronic ground state of the molecules and a thermal ensemble of rigid-rotor eigenstates. We formulate equations of motion of the two-color (laser plus x rays) rotational-electronic problem. The interaction with the laser is assumed to be nonresonant; it is described by an electric dipole polarizability tensor. X-ray absorption is approximated as a one-photon process. It is shown that the equations can be separated such that the interaction with the laser can be treated independently of the x rays. The laser-only density matrix is propagated numerically. After each time step, the x-ray absorption is calculated. We apply our theory to study adiabatic alignment of bromine molecules (Br2). The required dynamic polarizabilities are determined using the ab initio linear response methods coupled-cluster singles (CCS), second-order approximate coupled-cluster singles and doubles (CC2), and coupled-cluster singles and doubles (CCSD). For the description of x-ray absorption on the {sigma}g1s-->{sigma}u4p resonance, a parameter-free two-level model is used for the electronic structure of the molecules. Our theory opens up novel perspectives for the quantum control of x-ray radiation.

  4. A convenient alignment approach for x-ray imaging experiments based on laser positioning devices

    SciTech Connect

    Zhang Da; Donovan, Molly; Wu Xizeng; Liu Hong

    2008-11-15

    This study presents a two-laser alignment approach for facilitating the precise alignment of various imaging and measuring components with respect to the x-ray beam. The first laser constantly pointed to the output window of the source, in a direction parallel to the path along which the components are placed. The second laser beam, originating from the opposite direction, was calibrated to coincide with the first laser beam. Thus, a visible indicator of the direction of the incident x-ray beam was established, and the various components could then be aligned conveniently and accurately with its help.

  5. 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.

  6. 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.

  7. Portable weighing system with alignment features

    DOEpatents

    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.

  8. 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.

  9. New technology developments make passive laser/fiber alignment a reality

    NASA Astrophysics Data System (ADS)

    Collins, John V.; MacDonald, Brian M.; Lealman, I. F.; Jones, C. A.

    1996-01-01

    In this paper we report on the combination of a precision cleaved large spot laser and a silicon micromachined optical bench to achieve high coupling efficiencies by purely passive alignment. Coupling efficiencies of over 50% have been obtained by passively aligning precision cleaved large spot sized lasers to singlemode fiber on a silicon micromachined substrate. This is the highest known coupling figure reported for passive alignment. The packaging of semiconductor laser chips has always presented a range of technical problems due to the sub-micron tolerances required to obtain optimum coupling of the small laser spot size to the larger spot size of a singlemode fiber. Lasers have been developed that can ease these tolerances by matching the laser spot size to that of cleaved fiber. This is achieved by tapering the active layer to adiabatically expand the laser mode size. A method of controlling the physical size of laser diode chips to sub-micron accuracy has enabled these lasers to be bonded against substantial alignment features on a silicon micro-engineered optical bench which also includes a V-groove into which a cleaved single-mode optical fiber can be fixed. Results are also discussed for an alternative ferrule-based, non-hermetic laser packaging design which utilizes the relaxed alignment tolerances of the large spot lasers to give simple package assembly suitable for automation. Both of the packaging technologies discussed offer a viable route to obtaining the very low cost optoelectronic components required for fiber to the home networks.

  10. Field-induced alignment of oxygen and nitrogen by intense femtosecond laser pulses.

    PubMed

    Huang, Juan; Wu, Chengyin; Xu, Nan; Liang, Qingqing; Wu, Zhifeng; Yang, Hong; Gong, Qihuang

    2006-08-31

    Field-induced alignment of O2 and N2 was experimentally studied with laser intensities varying from 10(13) to 10(15) W/cm2. When the laser intensity was below the ionization threshold for these molecules, the interaction between the induced dipole moment of molecules and the laser electric field aligned the molecules along the laser polarization direction. After extinction of the exciting laser, the transient alignment revived periodically. Thus macroscopic ensembles of highly aligned O2 and N2 molecules were obtained under field-free conditions. When the laser intensity exceeded the ionization threshold for these molecules, multielectron ionization and Coulomb explosion occurred. Using two linearly polarized laser pulses with crossed polarization, we demonstrated that the rising edge of the laser pulse aligned the molecules along the laser polarization direction prior to ionization, which resulted in strong anisotropic angular distributions of exploding fragments. These results suggest that the degree of alignment should be taken into account when qualitatively comparing the ion yield of these molecules with their companion atoms. PMID:16928105

  11. 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

  12. 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.

  13. 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.

  14. Field-free molecular alignment of asymmetric top molecules using elliptically polarized laser pulses

    NASA Astrophysics Data System (ADS)

    Rouzée, A.; Guérin, S.; Faucher, O.; Lavorel, B.

    2008-04-01

    We show theoretically that a short specific elliptically polarized laser pulse driving an asymmetric top molecule can induce postpulse revivals of three-dimensional (3D) alignment. By choosing the field ellipticity resulting in the best compromise between the alignment of two molecular axes, we demonstrate that efficient 3D alignment can be achieved at low temperature. In the experiment, the field-free alignment of moderately cool ethylene molecules is probed by using a technique based on the optical Kerr effect. Control of 3D field-free alignment opens the door to a large range of applications in chemistry as well as in molecular optics.

  15. 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.

  16. 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.

  17. Alignment Tools Used to Locate a Wire and a Laser Beam in the VISA Undulator Project

    SciTech Connect

    Wolf, Z.; Ruland, R.; Dix, B.; Arnett, D.; /SLAC

    2005-08-17

    The Stanford Linear Accelerator Center is evaluating the feasibility of placing a free electron laser (FEL) at the end of the linear accelerator. The proposal is to inject electrons two thirds of the way down the linac, accelerate the electrons for the last one third of the linac, and then send the electrons into the FEL. This project is known as the LCLS (Linac Coherent Light Source). To test the feasibility of the LCLS, a smaller experiment VISA (Visual to Infrared SASE (Self Amplified Stimulated Emission) Amplifier) is being performed at Brookhaven National Laboratory. VISA consists of four wiggler segments, each 0.99 m long. The four segments are required to be aligned to the beam axis with an rms error less than 50 {micro}m [1]. This very demanding alignment is carried out in two steps [2]. First the segments are fiducialized using a pulsed wire system. Then the wiggler segments are placed along a reference laser beam which coincides with the electron beam axis. In the wiggler segment fiducialization, a wire is stretched through a wiggler segment and a current pulse is sent down the wire. The deflection of the wire is monitored. The deflection gives information about the electron beam trajectory. The wire is moved until its x position, the coordinate without wire sag, is on the ideal beam trajectory. (The y position is obtained by rotating the wiggler 90{sup o}.) Once the wire is on the ideal beam trajectory, the wire's location is measured relative to tooling balls on the wiggler segment. To locate the wire, a device was constructed which measures the wire position relative to tooling balls on the device. The device is called the wire finder. It will be discussed in this paper. To place the magnets along the reference laser beam, the position of the laser beam must be determined. A device which can locate the laser beam relative to tooling balls was constructed and is also discussed in this paper. This device is called the laser finder. With a total alignment

  18. 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

  19. 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.

  20. Dynamic alignment of CH 3I by strong picosecond laser pulses

    NASA Astrophysics Data System (ADS)

    Kaziannis, S.; Siozos, P.; Kosmidis, C.

    2005-01-01

    The angular distributions of the fragment ions of methyl iodide (CH 3I) irradiated by strong 35 ps laser pulses have been recorded at different wavelengths using a time-of-flight mass spectrometer. From the analysis of the angular distributions it is concluded that the singly and the transient doubly and triply charged parent ions are aligned by the laser beam (dynamic alignment). Under the present experimental conditions the CH 3I is adiabatically aligned. Molecular alignment has been observed for all the laser wavelengths (1064, 532, 355 and 266 nm) used and it is found to be more efficient at the longer one, while reaches saturation for laser intensities higher than 10 14 W/cm 2.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Nanostructure-enhanced laser tweezers for efficient trapping and alignment of particles

    PubMed Central

    Wilson, Benjamin K.; Mentele, Tim; Bachar, Stephanie; Knouf, Emily; Bendoraite, Ausra; Tewari, Muneesh; Pun, Suzie H.; Lin, Lih Y.

    2010-01-01

    We propose and demonstrate a purely optical approach to trap and align particles using the interaction of polarized light with periodic nanostructures to generate enhanced trapping force. With a weakly focused laser beam, we observed efficient trapping and transportation of polystyrene beads with sizes ranging from 10 μm down to 190 nm as well as cancer cell nuclei. In addition, alignment of non-spherical dielectric particles to a 1-D periodic nanostructure was achieved with low laser intensity without attachment to birefringent crystals. Bacterial cells were trapped and aligned with incident optical intensity as low as 17 μW/μm2. PMID:20720985

  6. 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.

  7. Reconstruction of three-dimensional molecular structure from diffraction of laser-aligned molecules.

    PubMed

    Yang, Jie; Makhija, Varun; Kumarappan, Vinod; Centurion, Martin

    2014-07-01

    Diffraction from laser-aligned molecules has been proposed as a method for determining 3-D molecular structures in the gas phase. However, existing structural retrieval algorithms are limited by the imperfect alignment in experiments and the rotational averaging in 1-D alignment. Here, we demonstrate a two-step reconstruction comprising a genetic algorithm that corrects for the imperfect alignment followed by an iterative phase retrieval method in cylindrical coordinates. The algorithm was tested with simulated diffraction patterns. We show that the full 3-D structure of trifluorotoluene, an asymmetric-top molecule, can be reconstructed with atomic resolution. PMID:26798781

  8. High accuracy alignment facility for the receiver and transmitter of the BepiColombo Laser Altimeter.

    PubMed

    Chakraborty, Sumita; Affolter, Michael; Gunderson, Kurt; Neubert, Jakob; Thomas, Nicolas; Beck, Thomas; Gerber, Michael; Graf, Stefan; Piazza, Daniele; Pommerol, Antoine; Roethlisberger, Guillaume; Seiferlin, Karsten

    2012-07-10

    The accurate co-alignment of the transmitter to the receiver of the BepiColombo Laser Altimeter is a challenging task for which an original alignment concept had to be developed. We present here the design, construction and testing of a large collimator facility built to fulfill the tight alignment requirements. We describe in detail the solution found to attenuate the high energy of the instrument laser transmitter by an original beam splitting pentaprism group. We list the different steps of the calibration of the alignment facility and estimate the errors made at each of these steps. We finally prove that the current facility is ready for the alignment of the flight instrument. Its angular accuracy is 23 μrad. PMID:22781273

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. The LACARA Vacuum Laser Accelerator Experiment: Beam Positioning and Alignment in a Strong Magnetic Field

    SciTech Connect

    Shchelkunov, Sergey V.; Marshall, T. C.; Hirshfield, J. L.; Wang, Changbiao; LaPointe, M. A.

    2006-11-27

    LACARA (laser cyclotron auto-resonance accelerator) is a vacuum laser accelerator of electrons that is under construction at the Accelerator Test Facility (ATF), Brookhaven National Laboratory. It is expected that the experiment will be assembled by September 2006; this paper presents progress towards this goal. According to numerical studies, as an electron bunch moves along the LACARA solenoidal magnetic field ({approx}5.2 T, length {approx}1 m), it will be accelerated from 50 to {approx}75 MeV by interacting with a 0.8 TW Gaussian-mode circularly polarized optical pulse provided by the ATF CO2 10.6{mu}m laser system. The LACARA laser transport optics must handle 10 J and be capable of forming a Gaussian beam inside the solenoid with a 1.4 mm waist and a Rayleigh range of 60 cm. The electron optics must transport a bunch having input emittance of 0.015 mm-mrad and 100 {mu}m waist through the magnet. Precision alignment between the electron beam and the solenoid magnetic axis is required, and a method to achieve this is described in detail. Emittance- filtering may be necessary to yield an accelerated bunch having a narrow ({approx}1%) energy-spread.

  14. Laser Alignment as a Route to Ultrafast Control of Electron Transport through Junctions

    SciTech Connect

    Reuter, Matthew G; Ratner, Mark A.; Seideman, Tamar

    2012-01-01

    We consider the extension of ultrafast laser alignment schemes to surface-adsorbed molecules, where the laser field coerces the molecule to reorient itself relative to the surface. When probed by a scanning tunneling microscope tip, this reorientation modifies the tip-molecule distance, and thus the tunneling current, suggesting a route to an ultrafast, nanoscale current switch. In addition to exploring the controllability of adsorbed molecules by moderately intense laser fields and discussing the fundamental differences of alignment behavior between surface-adsorbed molecules and gas phase molecules, we computationally investigate the quality of orientation with respect to field intensity, field duration, and the location of the tip. Overall, the molecule moves directly to its oriented configuration, which is reasonably insensitive to the tip location. These results collectively suggest the efficacy of using laser alignment schemes to control electron transport through junctions.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Digital control of the High-Altitude Balloon Experiment auto-alignment system

    NASA Astrophysics Data System (ADS)

    Schulthess, Marcus R.; Baugh, Steven

    1995-05-01

    The High Altitude Balloon Experiments (HABE) control architecture design focuses on establishing an inertial stabilized line-of-sight (LOS) for the tracking and laser pointing subsystems. High bandwidth LOS stabilization is implemented with an inertial reference measurement system. The Inertial Pseudo Star Reference Unit (IPSRU), and inertially stabilized two degree of freedom platform, generates an inertially stabilized alignment reference beam which probes the multiple aperture system. Fast steering mirrors (FSM) in optical alignment loops track the alignment reference beam performing jitter stabilization and boresight alignment. The auto alignment system operates in the primary aperture beam path, stabilizing the fine tracking sensor imagery and surrogate high energy laser pointing subsystem. Due to the superior performance of the IPSRU stabilization platform, aggregate LOS stabilization system base motion and optical jitter rejection is directly traceable to the auto alignment system control dynamics and sensor noise performance. Performance requirements specify two axis FSM control bandwidths of 500 Hz with a positioning resolution better that 300 nano-radians in output space. The digital control law is implemented in high performance digital processors with sample rates in excess of 15 kHz. This paper presents the bench top integration and testing of the digital auto alignment system beginning with a discussion as to the reason behind choosing a digital implementation, a opposed to a much simple analog implementation. A description of the error budget requirements of the HABE digital auto alignment loop follows. The components comprising the auto alignment loop, including mirror and processor hardware and software are described. Experimental objectives are presented with a description of the laboratory setup. Simulation models are constructed from component test data to aid in the development of the alignment system control architecture and discrete time

  20. Active alignment and vibration control system for a large airborne optical system

    NASA Astrophysics Data System (ADS)

    Kienholz, David A.

    2000-04-01

    Airborne optical or electro-optical systems may be too large for all elements to be mounted on a single integrating structure, other than the aircraft fuselage itself. An active system must then be used to maintain the required alignment between elements. However the various smaller integrating structures (benches) must still be isolated from high- frequency airframe disturbances that could excite resonances outside the bandwidth of the alignment control system. The combined active alignment and vibration isolation functions must be performed by flight-weight components, which may have to operate in vacuum. A testbed system developed for the Air Force Airborne Laser program is described. The payload, a full-scale 1650-lb simulated bench, is mounted in six degrees- of-freedom to a vibrating platform by a set of isolator- actuators. The mounts utilize a combination of pneumatics and magnetics to perform the dual functions of low-frequency alignment and high-frequency isolation. Test results are given and future directions for development are described.

  1. Survey and Alignment of the Fermilab Electron Cooling System

    SciTech Connect

    Oshinowo, Babatunde O'Sheg; Leibfritz, Jerry

    2006-09-01

    The goal of achieving the Tevatron luminosity of 3 x 10{sup 32} cm{sup -2}s{sup -1} requires Electron Cooling in the Recycler Ring to provide an increased flux of antiprotons. The Fermilab Electron Cooling system has been designed to assist accumulation of antiprotons for the Tevatron collider operations. The installation along with the survey and alignment of the Electron Cooling system in the Recycler Ring were completed in November 2004. The Electron Cooling system was fully commissioned in May 2005 and the first cooling of antiprotons was achieved in July 2005. This paper discusses the alignment methodology employed to survey and align the Electron Cooling system.

  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. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. [New concepts in aligner therapy with the orthocaps system].

    PubMed

    Khan, Wajeeh

    2014-09-01

    Orthodontic tooth movement with aligners poses challenges peculiar to removable appliances. The mechanical limitations of aligners can be overcome, to some extent, by increasing the aligner grip on teeth as well as by choosing elastic materials in their fabrication. Sound planning together with the use of auxiliaries can result in obtaining satisfactory results for the patients who seek an aesthetically pleasing and comfortable alternative to fixed appliance systems. The salient features of the Orthocaps System are the use of elastic thermoplastics, precision scanning, high pressure thermoforming, 3D interactive set-ups for treatment planning and approval, treatment evaluation at regular intervals during treatment and a unique attachment design (friction pads). PMID:25158748

  11. 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.

  12. Precision absolute measurement and alignment of laser beam direction and position.

    PubMed

    Schütze, Daniel; Müller, Vitali; Heinzel, Gerhard

    2014-10-01

    For the construction of high-precision optical assemblies, direction and position measurement and control of the involved laser beams are essential. While optical components such as beamsplitters and mirrors can be positioned and oriented accurately using coordinate measuring machines (CMMs), the position and direction control of laser beams is a much more intriguing task since the beams cannot be physically contacted. We present an easy-to-implement method to both align and measure the direction and position of a laser beam using a CMM in conjunction with a position-sensitive quadrant photodiode. By comparing our results to calibrated angular and positional measurements we can conclude that with the proposed method, a laser beam can be both measured and aligned to the desired direction and position with 10 μrad angular and 3 μm positional accuracy. PMID:25322238

  13. 4DAD: a device to align angularly and laterally a high-power laser using a conventional sighting telescope as metrology

    NASA Astrophysics Data System (ADS)

    Dupuy, Christophe; Pfrommer, Thomas; Bonaccini Calia, Domenico

    2012-09-01

    The 4DAD, Four Dimensions Alignment Device was developed in the frame of the project 4LGSF (4 Laser Guide Star Facility) for the AOF (Adaptive Optics Facility) on the ESO VLT (Very Large Telescope). It is used to accurately align with respect to kinematic interfaces and mirror alignment targets, a 20 W-class laser source in lateral and angular directions. 4DAD is of size 25x25x15cm and is based on a commercial CCD beam profiler. The incoming beam is highly attenuated at 589 nm and split in two parts through a set of beam conditioning optics. One beam is directed onto the detector revealing lateral movements whereas the other part is refocused to reflect angular changes in the incoming beam. Both lateral and angular beam positions are simultaneously recorded as pixel coordinates on the single CCD. The distinctive feature of 4DAD is its metrology, i.e. the pixel reference coordinates are recorded through the cross projection from a conventional sighting telescope. The device is capable of being used with a low-power white light sighting telescope (alignment reference) as well as with a high power laser beam (to be aligned) without any optical configuration change. Mounted on a reference frame, it can align all 4LGSF laser units beams, giving them equal optical interface and interchangeability. The sighting telescope is the main alignment equipment for the 4LGSF, thus all sub-systems, including 4DAD are aligned, merged, using a simple, single, practical and well-known alignment instrument. The alignment strategy, the design, and results of 4DAD are presented.

  14. Gimbal for aligning laser and lenslet arrays for coherent operation in an external cavity

    SciTech Connect

    Caunt, J.W.; Diadiuk, V. )

    1990-05-20

    We describe a miniature alignment stage designed for use with semiconductor diode laser and lenslet arrays. The device achieves 0.03-mrad angular and 0.3-{mu}m linear precision utilizing metal flexures and piezoelectric transducers in a mechanical arrangement that provides compactness and repeatability not obtainable with other types of components. It has been used successfully to coherently combine output of a linear diode laser array of five elements and can accommodate a 2-D array.

  15. Gimbal for aligning laser and lenslet arrays for coherent operation in an external cavity.

    PubMed

    Caunt, J W; Diadiuk, V

    1990-05-20

    We describe a miniature alignment stage designed for use with semiconductor diode laser and lenslet arrays. The device achieves 0.03-mrad angular and 0.3-microm linear precision utilizing metal flexures and piezoelectric transducers in a mechanical arrangement that provides compactness and repeatability not obtainable with other types of components. It has been used successfully to coherently combine output of a linear diode laser array of five elements and can accommodate a 2-D array. PMID:20563167

  16. Gimbal for aligning laser and lenslet arrays for coherent operation in an external cavity

    SciTech Connect

    Caunt, J.W.; Diadiuk, V.

    1990-05-20

    This reprint describes a miniature alignment stage designed for use with semiconductor diode laser and lenslet arrays. The device achieves 0.03-mrad angular and 0.3-micron linear precision utilizing metal flexures and piezoelectric transducers in a mechanical arrangement that provides compactness and repeatability not obtainable with other types of components. It has been used successfully to coherently combine output of a linear diode laser array of five elements and can accommodate a 2-D array.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

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

    DOE PAGESBeta

    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.

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

    PubMed Central

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

    2015-01-01

    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. 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. PMID:26503116

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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).

  9. Picosecond Laser Machining of Metallic and Polymer Substrates for Fluidic Driven Self-Alignment

    NASA Astrophysics Data System (ADS)

    Römer, G. R. B. E.; Cerro, D. Arnaldo Del; Pohl, R.; Chang, B.; Liimatainen, V.; Zhou, Q.; Veld, A. J. Huis In `t.

    Fluidic self-alignment of micro-components relies on creating a receptor site that is able to confine a liquid droplet. When a micro-component is brought in contact with the droplet, capillary forces move the component to its final position. A method to stop the advancing of a liquid from a receptor site, consists of creating geometrical features, such as edges around the site. A picosecond pulsed laser source was used to create suitable edges in a metallic and a polyimide substrate. Subsequently, the self-alignment capabilities of these sites were tested. The receptor sites in polyimide showed the highest success rate.

  10. Optical development system lab alignment solutions for the ICESat-2 ATLAS instrument

    NASA Astrophysics Data System (ADS)

    Evans, T.

    The ATLAS Instrument for the ICESat-2 mission at NASA's Goddard Space Flight Center requires an alignment test-bed to prove out new concepts. The Optical Development System (ODS) lab was created to test prototype models of individual instrument components to simulate how they will act as a system. The main ICESat-2 instrument is the Advanced Topographic Laser Altimeter System (ATLAS). It measures ice elevation by transmitting laser pulses, and collecting the reflection in a telescope. Because the round trip time is used to calculate distance, alignment between the outgoing transmitter beam and the incoming receiver beams are critical. An automated closed loop monitoring control system is currently being tested at the prototype level to prove out implementation for the final spacecraft. To achieve an error of less than 2 micro-radians, an active deformable mirror was used to correct the lab wave front from the collimated “ ground reflection” beam. The lab includes a focal plane assembly set up, a one meter diameter collimator optic, and a 0.8 meter flight spare telescope for alignment. ATLAS prototypes and engineering models of transmitter and receiver optics and sub-systems are brought in to develop and integrate systems as well as write procedures to be used in integration and testing. By having a fully integrated system with prototypes and engineering units, lessons can be learned before flight designs are finalized.

  11. 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.

  12. Automated alignment system for optical wireless communication systems using image recognition.

    PubMed

    Brandl, Paul; Weiss, Alexander; Zimmermann, Horst

    2014-07-01

    In this Letter, we describe the realization of a tracked line-of-sight optical wireless communication system for indoor data distribution. We built a laser-based transmitter with adaptive focus and ray steering by a microelectromechanical systems mirror. To execute the alignment procedure, we used a CMOS image sensor at the transmitter side and developed an algorithm for image recognition to localize the receiver's position. The receiver is based on a self-developed optoelectronic integrated chip with low requirements on the receiver optics to make the system economically attractive. With this system, we were able to set up the communication link automatically without any back channel and to perform error-free (bit error rate <10⁻⁹) data transmission over a distance of 3.5 m with a data rate of 3 Gbit/s. PMID:24978803

  13. Flexible polymeric rib waveguide with self-align couplers system.

    PubMed

    Huang, Cheng-Sheng; Wang, Wei-Chih

    2008-01-01

    The authors report a polymeric based rib waveguide with U shape self-align fiber couplers system using a simple micromolding process with SU8 as a molding material and polydimethysiloxane as a waveguide material. The material is used for its good optical transparency, low surface tension, biocompatibility, and durability. Furthermore, the material is highly formable. This unique fabrication molding technique provides a means of keeping the material and manufacturing costs to a minimum. The self-align fiber couplers system also proves a fast and simple means of light coupling. The flexible nature of the waveguide material makes this process ideal for a potential wearable optical sensor. PMID:22171151

  14. 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.

  15. Alignment and calibration of a focal neurotransmitter uncaging system.

    PubMed

    Sarkisov, Dmitry V; Wang, Samuel S-H

    2006-01-01

    Photolysis of caged compounds is a powerful tool for studying subcellular physiological functions. Here we describe protocols for the alignment and calibration of a focal uncaging system. We also report procedures for convenient quantitative calibration of uncaging. Using these methods, we can achieve submicron lateral resolution of photolysis and probe biological function in spines, the smallest signaling compartments of neurons. Initially, the entire alignment procedure takes 4-6 h to perform; periodic fine-tuning of the system takes 1-2 h. PMID:17406314

  16. 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.

  17. Laser multipass system with interior cell configuration.

    PubMed

    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 ≈2d(1-1/n) 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. PMID:22015409

  18. Linearly aligned superradiant Bose-Einstein condensates diffracted by a single short laser pulse

    NASA Astrophysics Data System (ADS)

    Inano, Ichiro; Nakamura, Keisuke; Morinaga, Atsuo

    2013-04-01

    Multiorder bidirectional superradiant Bose-Einstein condensates (BECs) were generated in a straight line by an irradiation of a single unidirectional short laser pulse along the long axis of a cigar-shaped sodium BEC in a magnetic trap. The probabilities of the diffracted BECs as a function of the laser intensity were well explained by the square of the Bessel functions and it was estimated that the intensity of the end-fire beam was 25% of the laser intensity. The backward diffractions disappeared at pulse duration longer than 5 μs because of energy conservation. The probability for the +first-order diffraction grew exponentially with pulse duration when the backward diffractions disappeared. We observed the linearly aligned diffracted BECs along the propagation direction of the laser beam, regardless of the aspect ratio of the condensates. This fact indicates that the end-fire beam is triggered by the small backreflection from the vacuum window.

  19. Pulse shape effect on rotational excitation and 2-D alignment alternation by elliptic laser pulses

    NASA Astrophysics Data System (ADS)

    Maan, Anjali; Ahlawat, Dharamvir Singh; Prasad, Vinod

    2016-04-01

    We examine theoretically the time-evolution of NAREX (non-adiabatic rotational excitation) and molecular 2-D alignment (2DA) interacting with a pair of elliptically polarized laser pulses. The pulse shapes taken are half-cycle pulse (HCP) and square pulse (SQP). By choosing the proper value of elliptically polarized field parameters, we demonstrate that efficient field-free 2DA alignment can be achieved. It is also shown that NAREX can be controlled by various laser parameters, out of which pulse shape plays the most significant role. The effect of pulse width along with elliptic parameter on probabilities of rotational states is also under concern. The delay time between the two pulses decides the maximum in 2DAs.

  20. Two-component, self-aligning laser vector velocimeter. [ultrasonic Bragg cell for atmospheric application

    NASA Technical Reports Server (NTRS)

    Farmer, W. M.; Hornkohl, J. O.

    1973-01-01

    A newly developed laser Doppler velocimeter is described. The basic optical component of the instrument is a two-dimensional ultrasonic Bragg cell. It is shown that use of this Bragg cell simplifies the optics usually required for the more conventional velocimeters, allows measurement of two-vector components of velocity, requires no adjustment of alignment mirrors, and enables both velocity component signals to be detected with a single detector. Some results from experiments using this velocimeter in an atmospheric application are described.

  1. NIF injection laser system

    NASA Astrophysics Data System (ADS)

    Wisoff, Peter J.; Bowers, Mark W.; Erbert, Gaylen V.; Browning, Donald F.; Jedlovec, Donald R.

    2004-05-01

    The National Ignition Facility (NIF) is a high-power, 192-beam laser facility being built at the Lawrence Livermore National Laboratory. The 192 laser beams that will converge on the target at the output of the NIF laser system originate from a low power fiber laser in the Master Oscillator Room (MOR). The MOR is responsible for generating the single pulse that seeds the entire NIF laser system. This single pulse is phase-modulated to add bandwidth, and then amplified and split into 48 separate beam lines all in single-mode polarizing fiber. Before leaving the MOR, each of the 48 output pulses are temporally sculpted into high contrast shapes using Arbitrary Waveform Generators (AWG). Each output pulse is then carried by optical fiber to the Preamplifier Module (PAM) where it is amplified to the multi-joule level using a diode-pumped regenerative amplifier and a multi-pass, flashlamp-pumped rod amplifier. Inside the PAM, the beam is spatially shaped to pre-compensate for the spatial gain profile in the main laser amplifiers. The output from the PAM is sampled by a diagnostic package called the Input Sensor Package (ISP) and then split into four beams in the Preamplifier Beam Transport System (PABTS). Each of these four beams is injected into one of NIF's 192 beam lines. The combination of the MOR, PAM, ISP and PABTS constitute the Injection Laser System (ILS) for NIF. This system has proven its flexibility of providing a wide variety of pulse shapes and energies during the first experiments utilizing four beam lines of NIF.

  2. 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.

  3. 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.

  4. The art of planning for optical systems integration and alignment

    NASA Astrophysics Data System (ADS)

    Sullivan, Joseph F.

    2015-09-01

    This will address Lessons Learned on the approaches that worked or did not work over various programs when integrating and aligning elements into fairly complex optical systems. The appropriate planning can prevent many unnecessary headaches and achieve the desired optical performance while optimizing integration efficiency.

  5. 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…

  6. 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.

  7. 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.

  8. Ultra-fast laser system

    SciTech Connect

    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.

  9. 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.

  10. Laser angle measurement system

    NASA Technical Reports Server (NTRS)

    Pond, C. R.; Texeira, P. D.; Wilbert, R. E.

    1980-01-01

    The design and fabrication of a laser angle measurement system is described. The instrument is a fringe counting interferometer that monitors the pitch attitude of a model in a wind tunnel. A laser source and detector are mounted above the mode. Interference fringes are generated by a small passive element on the model. The fringe count is accumulated and displayed by a processor in the wind tunnel control room. Optical and electrical schematics, system maintenance and operation procedures are included, and the results of a demonstration test are given.

  11. Geodynamic laser ranging system laser transmitter

    NASA Technical Reports Server (NTRS)

    Dallas, J. L.; Czechanski, J. P.; Coyle, D. B.; Zukowski, B. J.; Seery, B. D.

    1991-01-01

    A description is given of the requirements and design options in the development of a spaceborne laser transmitter for NASA's Geodynamic Laser Ranging System. Three different oscillators are considered. The first is an injection-seeded ring oscillator yielding 1 mJ of energy within a 120-ps pulse. The second is a frequency-modulated mode-locked oscillator emitting 0.30 nJ in a 20-ps pulse. The third is a self-starting, additive pulse mode-locked laser. Detailed design considerations and preliminary results of these lasers are reported as well as the design of a unique multipass amplifier.

  12. 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.

  13. Laser autostereoscopic projection system

    NASA Astrophysics Data System (ADS)

    Wang, Yuchang; Huang, Junejei

    2013-09-01

    The current autostereoscopic projection system is accomplished by array projectors. It is easy to realize optically but has a drawback with size. Another type is to place the shutter on the screen. It saves the volume but reduces the efficiency depending on how many views are produced. The shutter in the lens aperture has the same efficiency problem, too. To overcome these problems, a full HD autostereoscopic projector based on the lens aperture switching type is proposed. It has RGB laser sources and can produce 16-views or even higher stereoscopic images. This system removes the shutter in the lens aperture by the opti-mechanism itself. The specific light on the lens aperture coming from the point on the DMD is reflected to different angles. The proper angle of light is generated in the object side by the relay and folding system. The UHP lamps or the LED rays are difficult to constrain in a relative small cone angle. For this reason, the laser is applied to the design. The very small etendue of the laser is good for this architecture. The rays are combined by dichroic filter from RGB laser sources then forming and expanding to the mirror. The mirror is synchronized with DMD by the DSP control system. The images of different views are generated by DMD and specific position of the mirror. By the double lenticular screen, the lens aperture is imaged to the observer's viewing zone and the 3D scene is created.

  14. Laser interferometer micrometer system

    NASA Technical Reports Server (NTRS)

    Logue, S. H.

    1969-01-01

    Laser micrometer measures dimensions of precision gyro and gas bearing parts using the principle of measuring light phase changes rather than a direct fringe count. The system uses light beams to eliminate errors due to deformations and surface irregularities, and three interferometers.

  15. 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 ...

  16. 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.

  17. Time limit for the efficient coupling of relativistic femtosecond laser pulses into aligned nanowire arrays

    NASA Astrophysics Data System (ADS)

    Hollinger, R.; Bargsten, C.; Shlyaptsev, V.; Keiss, D.; Townsend, A.; Rockwood, A.; Wang, Y.; Wang, S.; Rocca, J. J.; Pukhov, A.; Kaymak, V.; London, R.; Tommasini, R.

    2015-11-01

    Recent experiments at Colorado State University have demonstrated volumetric heating of near solid density plasmas to multi-keV temperatures by intense high contrast femtosecond laser irradiation of vertically aligned nanostructures. A key parameter is the time for the heated nanowires to expand and fill the inter-wire gaps with a super-critical density plasma. After this time the laser light can no longer penetrate deep into the array, effectively terminating volumetric heating. We have gained information on the gap closure time for arrays with different wire spacing by monitoring the intensity of He-like lines from arrays of nickel nanowires while varying the laser pulse width from 50 fs to 250 fs. Experiments conducted at constant laser energy show that He-like α line emission from arrays of 80 nm diameter nanowires separated by 205 nm is observed for pulse widths of 200 fs. It is possible to find an optimal wire separation to match the pulse width of the driving laser. The results are relevant to scaling the scheme to high energy laser facilities that are characterized by longer pulses. Work supported by the Office of Fusion Energy Science of the US Dept of Energy, and the DTRA. A.P was supported by DFG project TR18, and R.L. and R.T. by LLNL Contract No. DE-AC52-07NA27344.

  18. Laser autoalignment system

    SciTech Connect

    Bernhard, R.J.; Lloyd, W.B.; Logan, D.R.; Minarik, R.W.

    1981-08-11

    An autoalignment system is disclosed for a laser having a pair of reflector assemblies capable of providing six degrees of freedom of movement to the reflector element formed as part of each of the reflector assemblies. Each reflector assembly is made up of a reflector unit, a gimbal knuckle joint and a translator mechanism. The interconnection between the reflector unit and the gimbal knuckle joint provides for two degrees of freedom while the translator mechanism and its interconnection with the gimbal knuckle joint provides the additional four degrees of freedom. Cooling of the reflector elements is accomplished by way of a coolant system which is incorporated within the autoalignment system of the laser, while motivation of the autoalignment system is in the form of a plurality of drivers operably connected to the various elements of the reflector assembly. During utilization of the system in a vibrational environment, the autoalignment system maintains the correct relationship between the reflecting elements of the laser as well as providing sufficient cooling thereof.

  19. Low cost, high performance, self-aligning miniature optical systems

    PubMed Central

    Kester, Robert T.; Christenson, Todd; Kortum, Rebecca Richards; Tkaczyk, Tomasz S.

    2009-01-01

    The most expensive aspects in producing high quality miniature optical systems are the component costs and long assembly process. A new approach for fabricating these systems that reduces both aspects through the implementation of self-aligning LIGA (German acronym for lithographie, galvanoformung, abformung, or x-ray lithography, electroplating, and molding) optomechanics with high volume plastic injection molded and off-the-shelf glass optics is presented. This zero alignment strategy has been incorporated into a miniature high numerical aperture (NA = 1.0W) microscope objective for a fiber confocal reflectance microscope. Tight alignment tolerances of less than 10 μm are maintained for all components that reside inside of a small 9 gauge diameter hypodermic tubing. A prototype system has been tested using the slanted edge modulation transfer function technique and demonstrated to have a Strehl ratio of 0.71. This universal technology is now being developed for smaller, needle-sized imaging systems and other portable point-of-care diagnostic instruments. PMID:19543344

  20. Selective Control over Fragmentation Reactions in Polyatomic Molecules Using Impulsive Laser Alignment

    NASA Astrophysics Data System (ADS)

    Xie, Xinhua; Doblhoff-Dier, Katharina; Xu, Huailiang; Roither, Stefan; Schöffler, Markus S.; Kartashov, Daniil; Erattupuzha, Sonia; Rathje, Tim; Paulus, Gerhard G.; Yamanouchi, Kaoru; Baltuška, Andrius; Gräfe, Stefanie; Kitzler, Markus

    2014-04-01

    We investigate the possibility of using molecular alignment for controlling the relative probability of individual reaction pathways in polyatomic molecules initiated by electronic processes on the few-femtosecond time scale. Using acetylene as an example, it is shown that aligning the molecular axis with respect to the polarization direction of the ionizing laser pulse does not only allow us to enhance or suppress the overall fragmentation yield of a certain fragmentation channel but, more importantly, to determine the relative probability of individual reaction pathways starting from the same parent molecular ion. We show that the achieved control over dissociation or isomerization pathways along specific nuclear degrees of freedom is based on a controlled population of associated excited dissociative electronic states in the molecular ion due to relatively enhanced ionization contributions from inner valence orbitals.

  1. 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

  2. Improving nuclear plant management effectiveness: Aligning strategy, systems, and people

    SciTech Connect

    Price, K.F.

    1991-11-01

    The effectiveness of any organization requires alignment of the appropriate financial, physical, and human resources. The manager's role is to efficiently utilize the right combination of these resources to achieve organizational objectives. In-depth studies of the nuclear programs of three major investor-owned utilities using a culture assessment process called the communication, values, and rewards (CVR) assessment have shown significant misalignments in those organizations' strategies, systems and people management. The CVR assessment related employees' perceptions of what drives their company's culture with the stated company strategic direction and management philosophies. Specifically, CVR provides a comparison of employee-held work-related values with those desired by management. Data obtained by a CVR assessment can be used to understand organizational misalignment and make changes to bring systems into alignment with corporate strategy and culture.

  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. Compact laser transmitter delivering a long-range infrared beam aligned with a monitoring visible beam.

    PubMed

    Lee, Hong-Shik; Kim, Haeng-In; Lee, Sang-Shin

    2012-06-10

    A compact laser transmitter, which takes advantage of an optical subassembly module, was proposed and demonstrated, providing precisely aligned collinear IR and visible beams. The collimated IR beam acts as a long-range projectile for simulated combat, carrying an optical pulsed signal, whereas the visible beam plays the role of tracking the IR beam. The proposed laser transmitter utilizes IR (λ(1)=905 nm) and visible (λ(2)=660 nm) light sources, a fiber-optic collimator, and a beam combiner, which includes a wavelength division multiplexing (WDM) filter in conjunction with optical fiber. The device was built via the laser welding technique and then evaluated by investigating the characteristics of the generated light beams. The IR collimated beam produced had a Gaussian profile and a divergence angle of ~1.3 mrad, and the visible monitoring beam was appropriately collimated to be readily discernible in the vicinity of the transmitter. The two beams were highly aligned within an angle of 0.004 deg as anticipated. Finally, we performed a practical outdoor field test to assess the IR beam with the help of a receiver. An effective trajectory was observed ranging up to 660 m with an overall detectable beam width of ~60 cm. PMID:22695673

  5. 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.

  6. Alignment and maintenance free all-fiber laser source for CARS microscopy based on frequency conversion by four-wave-mixing

    NASA Astrophysics Data System (ADS)

    Baumgartl, Martin; Chemnitz, Mario; Jauregui, Cesar; Meyer, Tobias; Dietzek, Benjamin; Popp, Jürgen; Limpert, Jens; Tünnermann, Andreas

    2012-01-01

    In this contribution we report on a novel approach for pump and stokes pulse generation in extremely compact all-fiber systems using parametric frequency conversion (four-wave-mixing) in photonic-crystal fibers. Representing a completely alignment-free approach, the all-fiber ytterbium-based short-pulse laser system provides intrinsically synchronized tunable two-color picosecond pulses emitted from a single fiber end. The system was designed to address important CH-stretch vibrational resonances. Strong CARS signals are generated and proved by spectroscopic experiments, tuning the laser over the resonance of toluene at 3050cm-1. Furthermore the whole laser setup with a footprint of only 30x30cm2 is mounted on a home-built laser-scanning-microscope and CARS imaging capabilities are verified. The compact turn-key system represents a significant advance for CARS microscopy to enter real-world, in particular bio-medical, applications.

  7. 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.

  8. 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.

  9. Antares alignment gimbal positioner

    SciTech Connect

    Day, R.D.; Viswanathan, V.K.; Saxman, A.C.; Lujan, R.E.; Woodfin, G.L.; Sweatt, W.C.

    1981-01-01

    Antares is a 24-beam 40-TW carbon-dioxide (CO/sub 2/) laser fusion system currently under construction at the Los Alamos National Laboratory. The Antares alignment gimbal positioner (AGP) is an optomechanical instrument that will be used for target alignment and alignment of the 24 laser beams, as well as beam quality assessments. The AGP will be capable of providing pointing, focusing, and wavefront optical path difference, as well as aberration information at both helium-neon (He-Ne) and CO/sub 2/ wavelengths. It is designed to allow the laser beams to be aligned to any position within a 1-cm cube to a tolerance of 10 ..mu..m.

  10. 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.

  11. 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.

  12. 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.

  13. 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)

  14. 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.

  15. Controlling rotational dynamics and alignment of molecule by infrared laser pulse.

    PubMed

    Arya, Urvashi; Tyagi, Ashish; Prasad, Vinod

    2013-02-01

    We investigate the effects of delayed infrared laser (IRL) pulse shape on the non-adiabatic rotational excitation and alignment of a polar molecule. We suggest a control scheme for choosing populations of molecular rotational states by wave packet interference. The rotational wave packets of polar molecule (here HBr) excited non-adiabatically by orienting pulse is controlled actually using the second delayed IRL pulse. By adjusting the time delay between the two laser pulses and the shape of delayed IRL pulse, constructive or destructive interference among these wave packets enables the population to be enhanced or repressed for the specific rotational state. We have used fourth order Runge-Kutta method to study the non-adiabatic rotational excitation (NAREX) dynamics. PMID:23220526

  16. Femtosecond laser modification of an array of vertically aligned carbon nanotubes intercalated with Fe phase nanoparticles

    PubMed Central

    2013-01-01

    Femtosecond lasers (FSL) are playing an increasingly important role in materials research, characterization, and modification. Due to an extremely short pulse width, interactions of FSL irradiation with solid surfaces attract special interest, and a number of unusual phenomena resulted in the formation of new materials are expected. Here, we report on a new nanostructure observed after the interaction of FSL irradiation with arrays of vertically aligned carbon nanotubes (CNTs) intercalated with iron phase catalyst nanoparticles. It was revealed that the FSL laser ablation transforms the topmost layer of CNT array into iron phase nanospheres (40 to 680 nm in diameter) located at the tip of the CNT bundles of conical shape. Besides, the smaller nanospheres (10 to 30 nm in diameter) are found to be beaded at the sides of these bundles. Some of the larger nanospheres are encapsulated into carbon shells, which sometime are found to contain CNTs. The mechanism of creation of such nanostructures is proposed. PMID:24004518

  17. 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

  18. National Ignition Facility sub-system design requirements automatic alignment system SSDR 1.5.5

    SciTech Connect

    VanArsdall, P.; Bliss, E.

    1996-09-01

    This System Design Requirement document establishes the performance, design, development, and test requirements for the Automatic Alignment System, which is part of the NIF Integrated Computer Control System (ICCS).

  19. Fabrication and testing of a prototype longwall face alignment system

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Fabrication and testing of a laser system for instantaneous location of a longwall shearer are summarized. Calculations and measurements for the design of a laser based system for monitoring and controlling the trajectory of the shearing machine as it progresses along the longwall face are reported. An early version was fabricated by employing simple mechanical contrivances and a standard miners lamp. It is concluded that the advantages of the early version is the ability to test the longwall face without approval from the Mine Safety and Health Administration.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. Fabrication and Alignment of Parts of the KASINICS Offner System

    NASA Astrophysics Data System (ADS)

    Mok, Seungwon; Lee, Sungho; Yuk, In-Soo; Park, Youngsik; Jin, Ho; Han, Jeong-Yeol; Moon, Bongkon; Cha, Sang-Mok; Kim, Geon Hee; Im, Myungshin

    2006-12-01

    The KASINICS (KASI Near Infrared Camera System) is a ground-based Near-Infrared (NIR) imaging instrument developed by the Korean Astronomy and Space Science Institute (KASI). In this paper, we report the test results of the KASINICS camera optics system which is comprised of a 1-1 Offner relay. We measure that the surface RMS fluctuations of the Offner mirrors are at the level of 10-1 - 10-2 of the target wavelengths, showing that the mirrors are sufficiently smooth for NIR observations. The alignment of the Offner optics system has been checked too. Our ray-tracing simulations find that the image quality should not degrade more than the pixel size of the KASINICS (40 μm), if a de-centering or a tilt of the Offner mirrors are within 5 mm, or 2.5 °. Our measurement shows that the de-centering or the tilt of the Offner mirrors are less than 1 mm or 0.5 °, assuring that the KASINICS image quality are not affected by the alignment errors. We have also measured that the optics resolution is 20 μm and it does not degrade more than 10 % over the detector surface area of 14.3 mm × 14.3 mm. Overall, we conclude that the KASINICS optics system satisfies the design requirements for NIR imaging observations.

  5. 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.

  6. 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.

  7. 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.

  8. Laser fusion target illumination system.

    PubMed

    Thomas, C E

    1975-06-01

    Laser fusion experiments require the focusing of very intense pulsed laser beams onto very small fuel pellets. All reported experiments to date have used lenses to focus one or more laser beams onto the target. This paper describes a combined refractive/reflective illumination system that provides nearly uniform irradiance with nearly orthogonal incidence over the complete spherical target, with only two laser beams. This illumination system was used in the experiments that produced the first known symmetric target implosions. Furthermore, these experiments produced what we believe were the first thermonuclear neutrons generated by a laser-driven implosion. PMID:20154815

  9. 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

  10. Laser system using ultra-short laser pulses

    SciTech Connect

    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.

  11. 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.

  12. 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. PMID:25490621

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

    NASA Astrophysics Data System (ADS)

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

    2011-07-01

    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.

  14. 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

  15. Triple Differential Cross Sections for Ionization of Laser-Aligned Mg Atoms by electron impact

    NASA Astrophysics Data System (ADS)

    Amami, Sadek; Madison, Don; Nixon, Kate; Murray, Andrew

    2013-09-01

    3DW (3-body distorted wave) triple differential cross sections have been calculated for electron impact ionization of magnesium atoms aligned by lasers. Calculations have been performed for the kinematics of the experiment performed by Kate Nixon and Andrew Murray at Manchester, England [K. L. Nixon and A. J. Murray 2011 Phys. Rev. Lett. 106, 123201]. An incident projectile was produced with energy of 41.91eV, scattered and ejected electrons were detected with equal energies (E1 =E2 =20eV), the scattered projectile was detected at a fixed angle of 30deg, and the ejected electrons were detected at angles ranging between 0circ; - 180circ; . The theoretical 3DW results will be compared with the experimental data. This work is supported by the US National Science Foundation under Grant.No.PHY-1068237.

  16. Dynamical alignment of H2^+ in an intense ultrashort laser pulse

    NASA Astrophysics Data System (ADS)

    Anis, Fatima; Cabrera-Trujillo, R.; Esry, B. D.

    2006-05-01

    We will present a study of ionization and dissociation of H2^+ in an intense ultrashort laser pulse. Our results include all degrees of freedom - classical for the nuclei and quantum mechanical for the electron. Similar previous calculations^1,2 have obtained the electronic wave function using a basis expansion. We, however, are solving the time-dependent Schr"odinger equation on a three dimensional grid in the lab frame. One of our goal is to study dynamical alignment of H2^+ and its fragments. We consider a distribution of initial nuclear positions and momenta so that our results are suitable for direct comparison with experiment. ^1M. Ullmann, T. Kunert, F. Grossmann, R. Schmidt, Phys. Rev. A 67, 013413 (2003). ^2E. Deumens, A. Diz, R. Longo, and Y. "Ohrn, Rev. Mod. Phys. 66, 917 (1994)

  17. Extracting Electron-Ion Differential Scattering Cross Sections for Partially Aligned Molecules by Laser-Induced Rescattering Photoelectron Spectroscopy

    NASA Astrophysics Data System (ADS)

    Okunishi, Misaki; Niikura, Hiromichi; Lucchese, R. R.; Morishita, Toru; Ueda, Kiyoshi

    2011-02-01

    We extract large-angle elastic differential cross sections (DCSs) for electrons scattering from partially aligned O2+ and CO2+ molecules using rescattering photoelectrons generated by infrared laser pulses. The extracted DCSs are in good agreement with those calculated theoretically, demonstrating that accurate DCSs for electron-ion scattering can be extracted from the laser-induced rescattering spectra, thus paving the way for dynamic imaging of chemical reactions by rescattering photoelectron spectroscopy.

  18. Redundant Strapdown Laser Gyro Navigation System

    NASA Technical Reports Server (NTRS)

    Mcpherson, B. W.; Walls, B. F.; White, J. B.

    1976-01-01

    For the last several years, NASA has pursued the development of low-cost high-reliability inertial navigation systems that would satisfy a broad spectrum of future space and avionics missions. Two specific programs have culminated in the construction of a Redundant Strapdown Laser Gyro Navigation System. These two programs were for development of a space ultrareliable modular computer (SUMC) and a redundant laser gyro inertial measurement unit (IMU). The SUMC is a digital computer that employs state-of-the-art large-scale integrated circuits configured in a functional modular breakdown. The redundant laser gyro IMU is a six-pack strapdown sensor package in a dodecahedron configuration which uses six laser gyros to provide incremental angular positions and six accelerometers for linear velocity outputs. The sensor arrangement allows automatic accommodation of two failures; a third failure can be tolerated provided it can be determined. The navigation system also includes redundant power supplies, built-in test-equipment (BITE) circuits for failure detection, and software which provides for navigation, redundancy management, and automatic calibration and alignment.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. Segment Alignment Maintenance System for the Hobby-Eberly Telescope

    NASA Technical Reports Server (NTRS)

    Rakoczy, John; Burdine, Robert (Technical Monitor)

    2001-01-01

    NASA's Marshall Space Flight Center, in collaboration with Blue Line Engineering of Colorado Springs, Colorado, is developing a Segment Alignment Maintenance System (SAMS) for McDonald Observatory's Hobby-Eberly Telescope (HET). The SAMS shall sense motions of the 91 primary mirror segments and send corrections to HET's primary mirror controller as the mirror segments misalign due to thermo -elastic deformations of the mirror support structure. The SAMS consists of inductive edge sensors. All measurements are sent to the SAMS computer where mirror motion corrections are calculated. In October 2000, a prototype SAMS was installed on a seven-segment cluster of the HET. Subsequent testing has shown that the SAMS concept and architecture are a viable practical approach to maintaining HET's primary mirror figure, or the figure of any large segmented telescope. This paper gives a functional description of the SAMS sub-array components and presents test data to characterize the performance of the subarray SAMS.

  8. 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.

  9. Near field intensity trends of main laser alignment images in the National Ignition Facility (NIF)

    NASA Astrophysics Data System (ADS)

    Leach, Richard R.; Beltsar, Ilona; Burkhart, Scott; Lowe-Webb, Roger; Miller-Kamm, Victoria; Salmon, Thad; Wilhelmsen, Karl

    2015-02-01

    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 and 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 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. Changes in light transmission from the NIF main laser over the three year time-frame are presented.

  10. Improved AMOLED with aligned poly-Si thin-film transistors by laser annealing and chemical solution treatments

    NASA Astrophysics Data System (ADS)

    Wu, G. M.; Chen, C. N.; Feng, W. S.; Lu, H. C.

    2009-12-01

    Low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFT) were prepared for the active-matrix organic light-emitting displays (AMOLED). The excimer laser annealing (ELA) recrystallization technique was employed with a chemical solution treatment process to improve the TFT characteristic uniformity and the AMOLED display image quality. The characteristics of the poly-Si array thin films were influenced by XeCl ELA optic module design, TFT device channel direction, and laser irradiation overlap ratio. The ELA system module provided aligned poly-Si grain size of 0.3 μm by the homogenization lens design. The chemical solution treatment process included a dilute HF solution (DHF), ozone (O 3) water, and buffer oxide etching solution (BOE). The PMOS TFT showed better field effect mobility of 87.6 cm 2/V s, and the threshold voltage was -1.35 V. The off current ( Ioff) was 1.25×10 -11 A, and the on/off current ratio was 6.27×10 6. In addition, the image quality of the AMOLED display was highly improved using the 2T1C structure design without any compensation circuit.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. An Intelligent Dynamic Alignment System for Interferometer of Fourier Transform Spectrometer

    NASA Astrophysics Data System (ADS)

    Yang, Kun; Zeng, Libo

    An intelligent dynamic alignment system for a Michelson interferometer which is applied to a Mid-infrared band Fourier transform spectrometer (FTS) is presented. Three photodiodes are used to detect the tilt of moving mirror opposite to fixed mirror with the assistance of the interfered signal of a reference He-Ne laser. This technique is based on detecting the phase difference of laser signal between every two diodes in two perpendicular directions. And four magnetic actuators behind the mounting brace of fixed mirror are used to change the pose of fixed mirror. The system is controlled by a digital signal processor (DSP) in real-time. A feedback algorithm is used to tilt fixed mirror following the action of moving mirror so as to keep both mirror planes in perpendicular. Experiment result shows that the relative tilt between two reflecting mirrors can be restricted in a range no more than ±1.5×10-6rad. This system is effective and reliable to be applied to scanning interferometer of Fourier transform spectrometer.

  19. 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.

  20. System modeling of the Thirty Meter Telescope alignment and phasing system

    NASA Astrophysics Data System (ADS)

    Dekens, Frank G.; Seo, Byoung-Joon; Troy, Mitchell

    2014-08-01

    We have developed a system model using the System Modeling Language (SysML) for the Alignment and Phasing System (APS) on the Thirty Meter Telescope (TMT). APS is a Shack-Hartmann wave-front sensor that will be used to measure the alignment and phasing of the primary mirror segments, and the alignment of the secondary and tertiary mirrors. The APS system model contains the ow-down of the Level 1 TMT requirements to APS (Level 2) requirements, and from there to the APS sub-systems (Level 3) requirements. The model also contains the operating modes and scenarios for various activities, such as maintenance alignment, post-segment exchange alignment, and calibration activities. The requirements ow-down is captured in SysML requirements diagrams, and we describe the process of maintaining the DOORS database as the single-source-of-truth for requirements, while using the SysML model to capture the logic and notes associated with the ow-down. We also use the system model to capture any needed communications from APS to other TMT systems, and between the APS sub-systems. The operations are modeled using SysML activity diagrams, and will be used to specify the APS interface documents. The modeling tool can simulate the top level activities to produce sequence diagrams, which contain all the communications between the system and subsystem needed for that activity. By adding time estimates for the lowest level APS activities, a robust estimate for the total time on-sky that APS requires to align and phase the telescope can be obtained. This estimate will be used to verify that the time APS requires on-sky meets the Level 1 TMT requirements.

  1. 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.

  2. Very high stability systems: LMJ target alignment system and MTG imager test setup

    NASA Astrophysics Data System (ADS)

    Compain, Eric; Maquet, Philippe; Kunc, Thierry; Marque, Julien; Lauer-Solelhac, Maxime; Delage, Laurent; Lanternier, Catherine

    2015-09-01

    Most of space instruments and research facilities require test equipment with demanding opto-mechanical stability. In some specific cases, when the stability performance directly drives the final performance of the scientific mission and when feasibility is questionable, specific methods must be implemented for the associated technical risk management. In present paper, we will present our heritage in terms of methodology, design, test and the associated results for two specific systems : the SOPAC-POS and the MOTA, generating new references for future developments. From a performance point of view, we will emphasis on following key parameters : design symmetry, thermal load management, and material and structural choices. From a method point of view the difficulties arise first during design, from the strong coupling between the thermal, mechanical and optical performance models, and then during testing, from the difficulty of conceiving test setup having appropriate performance level. We will present how these limitations have been overcome. SOPAC-POS is the target alignment system of the LMJ, Laser Mega Joule, the French inertial confinement fusion research center. Its stability has been demonstrated by tests in 2014 after 10 years of research and development activities, achieving 1μm stability @ 6m during one hour periods. MOTA is an Optical Ground Support Equipment aiming at qualifying by tests the Flexible Combined Imager (FCI). FCI is an instrument for the meteorological satellite MTG-I, a program of and funded by the European Space Agency and under prime contractorship of Thales Alenia Space. Optimized design will allow to get better than 0.2 μrad stability for one hour periods, as required for MTF measurement.

  3. 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.

  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. 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.

  6. Laser system of extended range

    NASA Technical Reports Server (NTRS)

    Lehr, C. G.

    1972-01-01

    A pulsed laser system was developed for range measurements from the earth to retroreflecting satellites at distances up to that of the moon. The system has a transportable transmitter unit that can be moved from one location to another. This unit consists of a 0.2 m coude refractor and a high radiance, neodymium-glass, frequency doubled laser that operates in a single transverse mode. It can be used for lunar or distant satellite ranging at any observatory that has a telescope with an aperture diameter of about 1.5 m for the detection of the laser return pulses. This telescope is utilized in the same manner customarily employed for the observation of celestial objects. A special photometric package and the associated electronics are provided for laser ranging.

  7. The Lunar Laser OCTL Terminal (LLOT) Optical Systems

    NASA Technical Reports Server (NTRS)

    Roberts, W. Thomas; Wright, Malcolm W.

    2013-01-01

    The Lunar Laser OCTL Terminal is an auxiliary ground station terminal for the Lunar Laser Communication Demonstration (LLCD). The LLOT optical systems exercise modulation and beam divergence control over six 10-watt fiber-based laser transmitters at 1568 nanometers, which act as beacons for pointing of the space-based terminal. The LLOT design transmits these beams from distinct sub-apertures of the F/76 OCTL telescope at divergences ranging from 110 microrad to 40 microrad. LLOT also uses the same telescope aperture to receive the downlink signal at 1550 nanometers from the spacecraft terminal. Characteristics and control of the beacon lasers, methods of establishing and maintaining beam alignment, beam zoom system design, co-registration of the transmitted beams and the receive field of view, transmit/receive isolation, and downlink signal manipulation and control are discussed.

  8. 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.

  9. Metrology systems for active alignment control of the Hobby-Eberly Telescope wide field corrector

    NASA Astrophysics Data System (ADS)

    Lee, Hanshin; Hill, Gary J.; Hart, Michael; Cornell, Mark E.; Savage, Richard; Vattiat, Brian; Perry, Dave; Moller, William M.; Rafferty, Tom; Taylor, Trey; Rafal, Marc D.

    2010-07-01

    The Hobby-Eberly Telescope (HET) Wide-Field Upgrade (WFU) will be equipped with new metrology systems to actively control the optical alignment of the new four-mirror Wide-Field Corrector (WFC) as it tracks sidereal motion with respect to the fixed primary mirror. These systems include a tip/tilt sensor (TTS), distance measuring interferometers (DMI), guide probes (GP), and wavefront sensors (WFS). While the TTS and DMIs are to monitor the mechanical alignment of the WFC, the WFSs and GPs will produce direct measurement of the optical alignment of the WFC with respect to the HET primary mirror. Together, these systems provide fully redundant alignment and pointing information for the telescope, thereby keeping the WFC in focus and suppressing alignment-driven field aberrations. We describe the current snapshot of these systems and discuss their roles, expected performance, and operation plans.

  10. The Alignment Test System for AXAF-I's High Resolution Mirror Assembly

    NASA Technical Reports Server (NTRS)

    Waldman, Mark

    1995-01-01

    The AXAF-1 High Resolution Mirror Assembly (HRMA) consists of four nested mirror pairs of Wolter Type-1 grazing incidence optics. The HRMA assembly and alignment will take place in a vibration-isolated, cleanliness class 100, 18 meter high tower at an Eastman Kodak Company facility in Rochester, NY. Each mirror pair must be aligned such that its image is coma-free, and the four pairs must be aligned such that their images are coincident. In addition, both the HRMA optical axis and focal point must be precisely known with respect to physical references on the HRMA. The alignment of the HRMA mirrors is measured by the HRMA Alignment Test System (HATS), which is an integral part of the tower facility. The HATS is configured as a double-pass, autocollimating Hartmann test where each mirror aperture is scanned to determine the state of alignment. This paper will describe the design and operation of the HATS.

  11. Automated retinal robotic laser system.

    PubMed

    Barrett, S F; Wright, C H; Jerath, M R; Lewis, R S; Dillard, B C; Rylander, H G; Welch, A J

    1995-01-01

    Researchers at the University of Texas and the USAF Academy have worked toward the development of a retinal robotic laser system. The overall 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. 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. Recent efforts have concentrated on combining the two subsystems into a single prototype capable of simultaneously controlling both lesion depth and placement. We have designated this combined system CALOSOS for Computer Aided Laser Optics System for Ophthalmic Surgery. Following the dual-use concept, this system is being adapted for clinical use as a retinal treatment system as well as a research tool for military laser-tissue interaction studies. PMID:7654990

  12. 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.

  13. 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…

  14. An automatic and accurate x-ray tube focal spot/grid alignment system for mobile radiography: System description and alignment accuracy

    SciTech Connect

    Gauntt, David M.; Barnes, Gary T.

    2010-12-15

    Purpose: A mobile radiography automatic grid alignment system (AGAS) has been developed by modifying a commercially available mobile unit. The objectives of this article are to describe the modifications and operation and to report on the accuracy with which the focal spot is aligned to the grid and the time required to achieve the alignment. Methods: The modifications include an optical target arm attached to the grid tunnel, a video camera attached to the collimator, a motion control system with six degrees of freedom to position the collimator and x-ray tube, and a computer to control the system. The video camera and computer determine the grid position, and then the motion control system drives the x-ray focal spot to the center of the grid focal axis. The accuracy of the alignment of the focal spot with the grid and the time required to achieve alignment were measured both in laboratory tests and in clinical use. Results: For a typical exam, the modified unit automatically aligns the focal spot with the grid in less than 10 s, with an accuracy of better than 4 mm. The results of the speed and accuracy tests in clinical use were similar to the results in laboratory tests. Comparison patient chest images are presented--one obtained with a standard mobile radiographic unit without a grid and the other obtained with the modified unit and a 15:1 grid. The 15:1 grid images demonstrate a marked improvement in image quality compared to the nongrid images with no increase in patient dose. Conclusions: The mobile radiography AGAS produces images of significantly improved quality compared to nongrid images with alignment times of less than 10 s and no increase in patient dose.

  15. 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.

  16. 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.

  17. High resolution laser imaging system

    NASA Astrophysics Data System (ADS)

    Kyle, Thomas G.

    1989-07-01

    Computations indicate that a synthetic aperture laser imaging system can provide images with 10-cm resolution at satellite ranges using a 10-W CW laser. When imaging satellites from the ground, the synthetic aperture system reduces atmospheric degradations. The system uses 20-cm diam receiver optics. The low laser power is made possible by using separate transmitter and receiver optics and coded pulses with a 50 percent transmitter duty cycle. The coded pulses are derived from Hadamard matrices for which there is an efficient algorithm to transform the received data into images. The synthetic aperture yields spatial resolutions independent of range, and the coded pulses result in an effective range dependence of r exp-2 instead of r exp-4.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Orientation and Alignment Echoes

    NASA Astrophysics Data System (ADS)

    Karras, G.; Hertz, E.; Billard, F.; Lavorel, B.; Hartmann, J.-M.; Faucher, O.; Gershnabel, Erez; Prior, Yehiam; Averbukh, Ilya Sh.

    2015-04-01

    We present one of the simplest classical systems featuring the echo phenomenon—a collection of randomly oriented free rotors with dispersed rotational velocities. Following excitation by a pair of time-delayed impulsive kicks, the mean orientation or alignment of the ensemble exhibits multiple echoes and fractional echoes. We elucidate the mechanism of the echo formation by the kick-induced filamentation of phase space, and provide the first experimental demonstration of classical alignment echoes in a thermal gas of CO2 molecules excited by a pair of femtosecond laser pulses.

  6. 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)

  7. 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

  8. 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.

  9. 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.

  10. Reconfigurable systems for sequence alignment and for general dynamic programming.

    PubMed

    Jacobi, Ricardo P; Ayala-Rincón, Mauricio; Carvalho, Luis G A; Llanos, Carlos H; Hartenstein, Reiner W

    2005-01-01

    Reconfigurable systolic arrays can be adapted to efficiently resolve a wide spectrum of computational problems; parallelism is naturally explored in systolic arrays and reconfigurability allows for redefinition of the interconnections and operations even during run time (dynamically). We present a reconfigurable systolic architecture that can be applied for the efficient treatment of several dynamic programming methods for resolving well-known problems, such as global and local sequence alignment, approximate string matching and longest common subsequence. The dynamicity of the reconfigurability was found to be useful for practical applications in the construction of sequence alignments. A VHDL (VHSIC hardware description language) version of this new architecture was implemented on an APEX FPGA (Field programmable gate array). It would be several magnitudes faster than the software algorithm alternatives. PMID:16342039

  11. 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.

  12. Optical alignment of pixelated 4f optical system using multiplexed filter.

    PubMed

    Manivannan, N; Neil, M A A; Balachandran, W

    2013-11-10

    Novel optical alignment techniques to perform precise alignment of a typical pixelated 4f optical system are presented in this paper. These techniques use optical multiplexed matched filters, which were designed using a simple, efficient iterative optimization algorithm, known as direct binary search. Three alignment challenges are identified: positioning, focusing, and magnification. The first two alignments were performed using the optical multiplexed matched filtering technique, and the last one was performed using a new optical arrangement. Experimental results of the new alignment techniques and a simple optical pattern recognition problem to demonstrate the benefits of the new alignment techniques are also presented. Two pixelated, electrically addressed spatial light modulators (128 × 128 pixels and one pixel width is 80 μm) were used to represent the input and filter planes. The results clearly show that the new alignment techniques allow the 4f system to be aligned to a precision of 80 μm in the x-y direction and 0.716 mm in the z direction. PMID:24216742

  13. 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

  14. 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. PMID:27179483

  15. 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.

  16. A distributed system for fast alignment of next-generation sequencing data

    PubMed Central

    Srimani, Jaydeep K.; Wu, Po-Yen; Phan, John H.; Wang, May D.

    2016-01-01

    We developed a scalable distributed computing system using the Berkeley Open Interface for Network Computing (BOINC) to align next-generation sequencing (NGS) data quickly and accurately. NGS technology is emerging as a promising platform for gene expression analysis due to its high sensitivity compared to traditional genomic microarray technology. However, despite the benefits, NGS datasets can be prohibitively large, requiring significant computing resources to obtain sequence alignment results. Moreover, as the data and alignment algorithms become more prevalent, it will become necessary to examine the effect of the multitude of alignment parameters on various NGS systems. We validate the distributed software system by (1) computing simple timing results to show the speed-up gained by using multiple computers, (2) optimizing alignment parameters using simulated NGS data, and (3) computing NGS expression levels for a single biological sample using optimal parameters and comparing these expression levels to that of a microarray sample. Results indicate that the distributed alignment system achieves approximately a linear speed-up and correctly distributes sequence data to and gathers alignment results from multiple compute clients.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Reflex ring laser amplifier system

    DOEpatents

    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.

  5. 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.

  6. Laser satellite power systems - Concepts and issues

    NASA Astrophysics Data System (ADS)

    Walbridge, E. W.

    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 a laser beam. The laser SPS is an alternative to the microwave SPS. Lasers and how they work are described, as are the types of lasers - electric discharge, direct and indirect solar pumped, free electron, and closed-cycle chemical - that are candidates for application in a laser SPS. The advantages of a laser SPS over the microwave alternative are pointed out. One such advantage is that, for the same power delivered to the utility busbar, land requirements for a laser system are much smaller (by a factor of 21) than those for a microwave system. The four laser SPS concepts that have been presented in the literature are described and commented on. Finally key issues for further laser SPS research are discussed.

  7. 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.

  8. 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.

  9. Dual-Laser Schlieren System

    NASA Technical Reports Server (NTRS)

    Owen, R. B.; Wintherow, W. K.

    1982-01-01

    Proposed schlieren system uses two lasers and two knife edges to simultaneously view perpendicular refractive-index gradients in a test volume. It is improvement over conventional schlieren systems, which monitor gradient along only one axis. Although originally developed to monitor materials-processing experiments in space, it should find application wherever there is need to study two-dimensional temperature, pressure, concentration or other gradients related to index of refraction.

  10. Polarization and ellipticity of high-order harmonics from aligned molecules generated by linearly polarized intense laser pulses

    NASA Astrophysics Data System (ADS)

    Le, Anh-Thu; Lucchese, R. R.; Lin, C. D.

    2010-08-01

    We present theoretical calculations for polarization and ellipticity of high-order harmonics from aligned N2, CO2, and O2 molecules generated by linearly polarized lasers. Within the rescattering model, the two polarization amplitudes of the harmonics are determined by the photo-recombination amplitudes for photons emitted with polarization parallel or perpendicular to the direction of the same returning electron wave packet. Our results show clear species-dependent polarization states, in excellent agreement with experiments. We further note that the measured polarization ellipse of the harmonic furnishes the needed parameters for a “complete” experiment in molecules.

  11. Inverse image alignment method for image mosaicing and video stabilization in fundus indocyanine green angiography under confocal scanning laser ophthalmoscope.

    PubMed

    Zhou, Yongjin; Xue, Hui; Wan, Mingxi

    2003-01-01

    An efficient image registration algorithm, the Inverse Compositional image alignment method based on minimization of Sum of Squared Differences of images, is applied in fundus blood vessel angiography under confocal scanning laser ophthalmoscope, to build image mosaics which have larger field of view without loss of resolution to assist diagnosis. Furthermore, based on similar technique, the angiography video stabilization algorithm is implemented for fundus documenting. The actual underlying models of motion between images and corresponding convergence criteria are also discussed. The experiment results in fundus images demonstrate the effectiveness of the registration scheme. PMID:14575786

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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

  17. 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.

  18. Experience of primary surface alignment for the LMT using a laser tracker in a non-metrology environment

    NASA Astrophysics Data System (ADS)

    Gale, David M.

    2012-09-01

    The 50-metre Large Millimeter Telescope (LMT) successfully completed first light observations in June 2011, operating with an initial 32.5-metre diameter collecting area. This reduced-area primary surface consists of 84 reflector panels measuring approximately 3x5m. During the construction phase, individual panels were assembled and adjusted to the specified rms surface error off-site, then installed and aligned on the antenna using a total station. Prior to first-light observations, panels were fine-tuned in piston, tip-tilt and twist using full-surface holography measurements to direct the movement of electromechanical actuators located at the four corners of each panel. In preparation for the next observing season the 32.5m primary is being refurbished and re-aligned on-site, using a commercial laser tracker for surface adjustment of each panel. For this task we have opted for the transfer of panels from the antenna surface to the telescope basement for adjustment, offering an enclosed environment with stable temperature, followed by reinstallation and measurement on the open-air antenna surface at night. In this paper we present our experiences on the use of a laser tracker to conduct panel surface measurement and adjustment on-site, at an isolated location 4,700m (15,000ft) above sea level and in the absence of dedicated metrology facilities. In section 2 we present the primary surface concept deployed at the LMT. Section 3 discusses the laser tracker equipment and data processing for panel surface measurement. Section 4 describes the panel adjustment process carried out in the site basement and presents examples of indoor panel metrology using the laser tracker. In section 5, we present our experiences to date of open-air measurement of panels installed on the antenna. Some conclusions are offered in section 6.

  19. Optical system for Argus 355-nm 90-mm aperture target-illumination experiments

    SciTech Connect

    Johnson, B.C.; Boyd, R.; Hermes, G.; Hildum, J.S.; Linford, G.; Martin, W.E.

    1982-02-01

    The requirements of laser alignment, crystal tuning, target alignment, and laser beam diagnosis are provided by this optical system. Initial setup and preshot alignment techniques are discussed. Layout and operation are contrasted with the 532 nm target experiments.

  20. 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.

  1. 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

  2. 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.

  3. Highly aligned lipid membrane systems in the physiologically relevant "excess water" condition.

    PubMed Central

    Katsaras, J

    1997-01-01

    The "excess water" condition in biologically relevant systems is met when a membrane mesophase coexists with excess bulk water. Further addition of water to such a system results in no change to any of the system's physical properties (e.g., transition temperature, repeat spacing, and structural mesophases). Moreover, because biological membranes are anisotropic systems, many of their properties are best studied using aligned samples. Although model membrane systems are routinely aligned, they have traditionally been hydrated with water vapor. It is well known that membranes exposed to water vapor at 100% humidity do not imbibe the same quantity of water as a sample in contact with liquid water. As such, membranes that have been hydrated with water vapor have physical properties different from those of membranes dispersed in water. Because of this shortcoming, aligned membranes have not been utilized to their full potential. Here we present a novel and simple method of aligning model membrane systems under conditions of excess water, which will make possible, for the first time, a variety of techniques (e.g., neutron and x-ray diffraction, nuclear magnetic resonance, electron spin resonance, attenuated total reflection infrared spectroscopy, etc.) for studying such systems under physiologically relevant conditions. In addition, when dealing with samples of limited availability, the system allows for the conditions (buffer pH and ionic strength) to be altered without any effect on the sample's alignment. Images FIGURE 1 PMID:9414206

  4. [The alignment of the optical system for 216 coude focus echelle spectrometer].

    PubMed

    Zhu, Y; Pan, J

    1997-04-01

    This paper gives a brief introduction about the structure of the echelle spectrometer which was installed at coude focus of the chinese 2. 16 meter astronomical telescope. According to the design requirment of this echelle spectrometer, the main points and steps of alignment of optical system are analysed. Authors work out a practical alignment scheme in which the fewest auxiliary tools are used. PMID:15810402

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. High power laser perforating tools and systems

    DOEpatents

    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.

  10. Shiva automatic pinhole alignment

    SciTech Connect

    Suski, G.J.

    1980-09-05

    This paper describes a computer controlled closed loop alignment subsystem for Shiva, which represents the first use of video sensors for large laser alignment at LLNL. The techniques used on this now operational subsystem are serving as the basis for all closed loop alignment on Nova, the 200 terawatt successor to Shiva.

  11. System evaluations of laser power beaming options

    NASA Technical Reports Server (NTRS)

    Montgomery, Edward E., IV

    1992-01-01

    The major technology options for high-energy FELs and adaptive optics available to the Space Laser Energy (SELENE) program are reviewed. Initial system evaluations of these options are described. A feasibility assessment of laser power beaming is given.

  12. 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

  13. A Diode Laser System for Synchronous Photoinjection

    SciTech Connect

    Poelker, M., Hansknecht, J.

    1997-12-31

    A laser system, which is composed of a gain switched diode seed laser and a single-pass diode optical amplifier, is used to drive the polarized electron source at Jefferson Lab. The system emits pulsed laser light synchronized to the accelerating cavity radio frequency (rf) at 1497 MHz or the third subharmonic, 499 MHz. The maximum average output power from the laser system is 500 mW and the optical pulse width is 60 to 80 ps. The laser system is compact and very reliable operating remotely for many days without attention.

  14. Virtual alignment of x-ray cone-beam tomography system using two calibration aperture measurements

    NASA Astrophysics Data System (ADS)

    Bronnikov, Andrei V.

    1999-02-01

    In cone-beam tomography, relatively small misalignment of the imaging system is geometrically magnified and may cause severe distortion of the reconstructed image. We describe a method for alignment of a cone-beam tomography system built on an x-ray microfocus tube, an image intensifier, and a high-resolution CCD camera. To obtain geometrical parameters of system misalignment, we suggest measuring two 180-deg- opposed cone-beam radiographs of a specially manufactured calibration aperture. An advantage of the aperture over other calibration objects is that we can easily restore its idealized picture by applying a certain threshold to the measured data. The method permits the lateral displacement vector and lateral tilt angle to be accurately found. Unlike other alignment methods, our approach enables virtual system alignment by using mathematical processing of the measured data, rather than moving the parts of the system. The virtually aligned system data are used for 3D image reconstruction by a standard filtered backprojection algorithm. Experimental results demonstrate considerable improvement of the image quality after applying the alignment method suggested.

  15. 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.

  16. The SLAC polarized electron source laser system

    SciTech Connect

    Frisch, J.

    1995-10-01

    The Stanford Linear Collider (SLC) has operated a polarized photocathode electron source and titanium sapphire laser for high energy physics collisions for over 6,500 hours of nearly continuous operation. The laser system for the source has demonstrated > 98.5% total uptime for the duration of the experiment. The laser system uses a pair of titanium sapphire oscillators pumped by frequency doubled YAG lasers to produce 2ns, 250 {micro}J pulses at wavelengths from 740nm to 870nm.

  17. 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…

  18. 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…

  19. 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

  20. 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.

  1. Experimental nonlinear laser systems: Bigger data for better science?

    NASA Astrophysics Data System (ADS)

    Kane, D. M.; Toomey, J. P.; McMahon, C.; Noblet, Y.; Argyris, A.; Syvridis, D.

    2014-10-01

    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.

  2. 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.

  3. Molecular Alignment Effects in Ammonia at 6.14 μm, Using a Down-Chirped Quantum Cascade Laser Spectrometer

    NASA Astrophysics Data System (ADS)

    Hay, K. G.; Duxbury, G.; Langford, N.

    2009-06-01

    In recent intra-pulse experiments in acetylene we have seen the generation of short emission pulses using the fast frequency down-chirp of a pulsed quantum cascade (QC)laser. These follow the absorptive part of rapid passage signals and are caused by the effects of molecular alignment in low pressure gases. These effects occur when the sweep rate of a laser through a Doppler broadened line is much faster than the collisional relation rate. At higher pressures of the pure gas, a series of free induction decay signals may often be observed. In our current spectrometer using a 6.14 μm, laser, in which both the bandwidth of the detection system and the temperature stabilisation of the QC laser itself have been greatly improved, we have been able to study the time dependence of rapid passage effects in ammonia. Using pulses of duration up to 2 microseconds, within which the chirp rate varies from about 100 MHz/ns at the beginning to very slow rate approaching 6 MHz/ns at the end, we can study the interplay between chirp rate and collision processes. By using the base temperature tuning of the laser we can set the centre of the chosen line at the appropriate position within the scan. The absorption path length within our astigmatic Herriott cell is 60 m, so that the gas pressures used are very low. As the QC emission bandwidth chosen lies close to the centre of the ν _4 band of ammonia, a large number of low J transitions may be studied in detail. K. G. Hay,G. Duxbury, and N. Langford J. Mod. Opt. 55, 3293 2008.

  4. 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

  5. Design of diode laser systems for solid state laser pumping

    NASA Astrophysics Data System (ADS)

    Michel, D.; Luethy, Willy A.; Weber, Heinz P.

    2003-11-01

    In contrast to flashlamps the emission of single stripe laser diodes is highly directional and can be focused rather easily to small spots, which gives access to very high pump intensities. Numerical arrangements are possible for transferring the pump radiation to the solid state laser media. In this paper the most important concepts of diode laser systems for pumping solid state lasers are summarized and described. Thereby the aim is to find the most efficient and powerful method for endpumping a Yb3+-double clad fiber.

  6. 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.

  7. 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

  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. 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.

  10. An automated system for the alignment of large area modular solar simulators

    NASA Technical Reports Server (NTRS)

    Vincent, J. P.; Polak, L. F.; Fisher, P. S.

    1972-01-01

    A real-time optical alignment and diagnostic system is being assembled for installation at the Space Environment Simulation Laboratory. This system will be used to measure and analyze the performance of optical components, assemblies, and full modules. This information, in turn, is used to align assemblies and modules. The system capability includes such functions as the generation and updating of a catalog, which serves as permanent record, in addition to providing the capability to predict in-chamber performance of optics combinations before they are mounted in the chamber.

  11. Kinoform/lens system for injecting a high power laser beam into an optical fiber

    SciTech Connect

    Sweatt, W.C.; Farn, M.W.

    1993-11-01

    A method for injecting a high peak power multimode YAG laser beam into an optical fiber has been developed. The design minimizes the peak irradiance on the fiber`s entrance face and reduces its dependence on the laser`s mode structure and the system alignment. A simple lens and a specially designed kinoform (or binary optics element) operate together to transform a 5 mm diameter laser beam into two concentric ring foci that fit on the 400 {mu}m diameter fiber face.

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

    DOE PAGESBeta

    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

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

    NASA Astrophysics Data System (ADS)

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

    2016-03-01

    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.

  14. 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

  15. 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.

  16. 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

  17. 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

  18. Eccentricity Inferences in Multi-planet systems with Transit Timing: Degeneracies and Apsidal Alignment

    NASA Astrophysics Data System (ADS)

    Jontof-Hutter, Daniel; Van Laerhoven, Christa L.; Ford, Eric B.

    2016-05-01

    Hundreds of multi-transiting systems discovered by the Kepler mission show Transit Timing Variations (TTV). In cases where the TTVs are uniquely attributable to transiting planets, the TTVs enable precise measurements of planetary masses and orbital parameters. Of particular interest are the constraints on eccentricity vectors that can be inferred in systems of low-mass exoplanets.The TTVs in these systems are dominated by a signal caused by near-resonant mean motions. This causes the well-known near-degeneracy between planetary masses and orbital eccentricities. In addition, it causes a degeneracy between the eccentricities of interacting planet pairs.For many systems, the magnitude of individual eccentricities are weakly constrained, yet the data typically provide a tight constraint on the posterior joint distribution for the eccentricity vector components. This permits tight constraints on the relative eccentricity and degree of alignment of interacting planets.For a sample of two and three-planet systems with TTVs, we highlight the effects of these correlations. While the most eccentric orbital solutions for these systems show apsidal alignment, this is often due to the degeneracy that causes correlated constraints on the eccentricity vector components. We compare the likelihood of apsidal alignment for two choices of eccentricity prior: a wide prior using a Rayleigh distribution of scale length 0.1 and a narrower prior with scale length 0.02. In all cases the narrower prior decreased the fraction of samples that exhibited apsidal alignment. However, apsidal alignment persisted in the majority of cases with a narrower eccentricity prior. For a sample of our TTV solutions, we ran simulations of these systems over secular timescales, and decomposed their eccentricity eigenmodes over time, confirming that in most cases, the eccentricities were dominated by parallel eigenmodes which favor apsidal alignment.

  19. 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. PMID:20048888

  20. 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.

  1. 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.

  2. Aligning Food Systems Policies to Advance Public Health

    PubMed Central

    Muller, Mark; Tagtow, Angie; Roberts, Susan L.; MacDougall, Erin

    2009-01-01

    The involvement of public health professionals in food and agricultural policy provides tremendous opportunities for advancing the public's health. It is particularly challenging, however, for professionals to understand and consider the numerous policy drivers that impact the food system, which range from agricultural commodity policies to local food safety ordinances. Confronted with this complexity in the food system, policy advocates often focus on narrow objectives with disregard for the larger system. This commentary contends that, in order to be most effective, public health professionals need to consider the full range of interdependent policies that affect the system. Food policy councils have proven to be an effective tool, particularly at the local and state level, for developing comprehensive food systems policies that can improve public health. PMID:23144671

  3. The LES of the channel flow in a non aligned system of coordinates

    NASA Astrophysics Data System (ADS)

    Germano, Massimo; Abbà, Antonella

    2010-11-01

    The plane channel flow continues to be a very important test case for the verification and the validation of LES. In the channel flow test there is a privileged direction, usually one reference axis is oriented along the stream and the size of the computational box is increased in the streamwise direction in order to capture correctly the dominant turbulent structures and to produce a fully developed flow. All that is peculiar of this particular test, and in this paper we will investigate the sensitivity of the channel test to the particular alignment of the coordinate system with the mean flow. In a non aligned system of coordinates there is no privileged direction, there are two components of the forcing term, the mean pressure gradient, and the homogeneities of the Reynolds stresses are destroyed. In our paper we simulate the channel flow in a rotated system of coordinates, and we compare the results with the stream aligned data. We think that this test could evidence the flexibility of different LES codes and LES subgrid models to simulate the turbulent flow and to capture the correct statistical values in non aligned conditions. The first preliminary results are slightly contradictory: the resolved Reynolds stresses seem degraded while the mean flow is better predicted. The dynamic anisotropic subgrid model of Abbà, Cercignani and Valdettaro seems well fitted to represent correctly the large scales in non aligned conditions.

  4. 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.

  5. 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.

  6. 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

  7. 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

  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. Active mirror alignment control system for the MACE telescope

    NASA Astrophysics Data System (ADS)

    Kulgod, S. V.; Pious, Lizy; Chadda, V. K.; Kaul, S. R.; Yadav, K. K.; Koul, R.

    2002-03-01

    The conceptual design of an active mirror contol system for the MACE telescope, being set up by the Bhabha Atomic Research Centre at Mt. Abu, is described. Preliminary results obtained from recent laboratory trials are also described.

  10. 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...

  11. 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.

  12. Laser Doppler Blood-Flow Signals from Human Teeth during an Alignment and Leveling Movement Using a Superelastic Archwire

    PubMed Central

    Nogueira, Gessé Eduardo Calvo

    2013-01-01

    Objective. The purpose of this study was to examine alterations in blood-flow signals (BFS) from human teeth during an alignment and leveling phase (superelastic wire 0.014′′) in a clinical orthodontic treatment using laser doppler flowmetry (LDF). Materials and Methods. Recordings were made in 12 maxillary left central incisors. The basal value of the BFS from each tooth (without orthodontic forces) was compared with the corresponding values of BFS during four periods of observation: 20 minutes, 48 hours, 72 hours, and one month after the activation of the orthodontic appliance. Results. Statistically significant decrease of BFS was observed at 20 minutes, 48 hours, and 72 hours (P < 0.05). No differences were found comparing BFS on day 30 and the corresponding basal values. Conclusion. Under real clinical conditions, a significant decrease in BFS was verified during the initial phase of the treatment, followed by a recovery on day 30. PMID:24171115

  13. Laser fiber optics ordnance initiation system

    NASA Technical Reports Server (NTRS)

    Yang, L. C.

    1976-01-01

    Recent progress on system development in the laser initiation of explosive devices is summarized. The topics included are: development of compact free-running mode and Q-switched lasers, development of low-loss fiber optic bundles and connectors, study of nuclear radiation effects on the system, characterization of laser initiation sensitivities of insensitive high explosives, and the design methods used to achieve attractive system weight and cost savings. Direction for future work is discussed.

  14. Mirror Quality Required By The Antares Laser System

    NASA Astrophysics Data System (ADS)

    Sweatt, W. C.

    1980-11-01

    The Antares laser system is a large (100 kJ) CO2 pulse laser operating at 10.6 pm. The system has 72 beam lines, each with an aperture of 900 cm2. The system will be composed primarily of large copper-faced mirrors whose principal dimensions range up to 65 cm. These mirrors will be single-point diamond turned (SPDT) at the Y-12 facility of Union Carbide Corporation in Oak Ridge, Tennessee. We have had to develop surface quality specifications for these mirrors. These specifications were initially set at 50 nm peak-to-valley (p-v) surface error for the microsurface over 0.5-mm areas and 500 nm (p-v) over the whole mirror surface. In this paper an attempt has been made to refine these specifications to a more phys-ically meaningful set based on the performance of the system. The optical specification for Antares is that 80% of the energy from each beam should be deliverable inside a 400-μm circle. The diffraction limited focal spot is 160 pm across, so small amounts of low spa-tial frequency wavefront aberrations are acceptable. This is the "figure error" and can be represented by a best-fit fourth-order polynomial. It is specified separately from the higher spatial frequency "subfigure" errors that diffract light out of the 400-μm circle. Antares will have a completely automatic alignment and centering system. A more versatile and less expensive alignment system can be developed if the alignment is done with visible light. This tightens the tolerances on the microsurface but not the figure error. These requirements, along with several lesser ones, must be considered when tolerancing the mirror quality. It appears that the SPDT mirrors turned at Y-12 will meet our minimum requirements.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Cryogenic performance of a high precision photogrammetry system for verification of the James Webb Space Telescope Integrated Science Instrument Module and associated ground support equipment structural alignment requirements

    NASA Astrophysics Data System (ADS)

    Nowak, Maria D.; Cleveland, Paul E.; Cofie, Emmanuel; Crane, J. Allen; Davila, Pamela S.; Eegholm, Bente H.; Hammond, Randolph P.; Heaney, James B.; Hylan, Jason E.; Johnston, John D.; Ohl, Raymond G.; Orndorff, Joseph D.; Osgood, Dean L.; Redman, Kevin W.; Sampler, Henry P.; Smee, Stephen A.; Stock, Joseph M.; Threat, Felix T.; Woodruff, Robert A.; Young, Philip J.

    2010-08-01

    The James Webb Space Telescope (JWST) is a general astrophysics mission which consists of a 6.6m diameter, segmented, deployable telescope for cryogenic IR space astronomy (~35K). The JWST Observatory architecture includes the Optical Telescope Element and the Integrated Science Instrument Module (ISIM) element that contains four science instruments (SI) including a Guider. The alignment philosophy of ISIM is such that the cryogenic changes in the alignment of the SI interfaces are captured in the ISIM alignment error budget. The SIs are aligned to the structure's coordinate system under ambient, clean room conditions using laser tracker and theodolite metrology. The ISIM structure is thermally cycled and temperature-induced structural changes are concurrently measured with a photogrammetry metrology system to ensure they are within requirements. We compare the ISIM photogrammetry system performance to the ISIM metrology requirements and describe the cryogenic data acquired to verify photogrammetry system level requirements, including measurement uncertainty. The ISIM photogrammetry system is the baseline concept for future tests involving the Optical Telescope Element (OTE) and Observatory level testing at Johnson Space Flight Center.

  1. Systems modeling for laser IFE

    NASA Astrophysics Data System (ADS)

    Meier, W. R.; Raffray, A. R.; Sviatoslavsky, I. N.

    2006-06-01

    A systems model of a laser-driven IFE power plant is being developed to assist in design trade-offs and optimization. The focus to date has been on modeling the fusion chamber, blanket and power conversion system. A self-consistent model has been developed to determine key chamber and thermal cycle parameters (e.g., chamber radius, structure and coolant temperatures, cycle efficiency, etc.) as a function of the target yield and pulse repetition rate. Temperature constraints on the tungsten armor, ferritic steel wall, and structure/coolant interface are included in evaluating the potential design space. Results are presented for a lithium cooled first wall coupled with a Brayton power cycle. LLNL work performed under the auspices of the US Department of Energy by the University of California LLNL under Contract W-7405-Eng-48.

  2. 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.

  3. 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

  4. 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

  5. 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.

  6. 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.

  7. Alignment of the ALICE Inner Tracking System with Cosmic-Ray Tracks

    SciTech Connect

    Aamodt, K.; Awes, Terry C; Enokizono, Akitomo; Silvermyr, David O; ALICE, Collaboration

    2010-03-01

    ALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 {micro}m in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10{sup 5} charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.

  8. Laser trigger system for the Jupiter module

    SciTech Connect

    Paiva, R.; Sundvoid, S.; Morelli, G.; Powell, C.; Hamil, R.; Corley, J.; Pankuch, P.; Law, K.; Alexander, J.

    1995-10-01

    A UV laser trigger system has been designed to trigger the eight SF6 filled high voltage switches in the Jupiter module. The system is compact and modular, allowing for approximately thirty lasers to be triggered simultaneously in the full Jupiter design. The laser will be kinematically mounted near the high voltage section to minimize the path length to the high voltage switches and decrease the sensitivity to misalignment. The laser system is specifically built for the purpose of triggering the Jupiter module. It is a 265 nm UV laser system designed to generate eight simultaneous laser pulses of 10 mJ each with a 13 nsec pulsewidth. A 1061 nm solid-state Nd:Cr:GSGG laser is frequency quadrupled with a two stage doubling process. The 1061 nm fundamental laser energy is frequency doubled with a type II KTP crystal to generate 530 nm energy. The 530 nm output is frequency doubled with a type I KD*P crystal to generate 265 nm energy. The 265 nm pulse is split into eight parallel channels with a system of partially reflecting mirrors. Low timing jitter and a stable energy output level for the system were achieved. The entire optical system was packaged in a rugged, sealed aluminum structure 10 in. {times} 19 in. {times} 2.75 in. The size of the laser electronics unit is 7 in. {times} 8 in. {times} 8 in.

  9. 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.

  10. 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.

  11. 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

  12. 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

  13. 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.

  14. 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;…

  15. A Sense of Balance: District Aligns Personalized Learning with School and System Goals

    ERIC Educational Resources Information Center

    Donsky, Debbie; Witherow, Kathy

    2015-01-01

    This article addresses the challenge of personalizing learning while also ensuring alignment with system and school improvement plans. Leaders of the York Region District School Board in Ontario knew that what took their high-performing school district from good to great would not take it from great to excellent. The district's early model of…

  16. 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.

    2014-12-01

    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.

  17. 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

  18. A laser scanning system for metrology and viewing in ITER

    SciTech Connect

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

    1996-05-01

    The construction and operation of a next-generation fusion reactor will require metrology to achieve and verify precise alignment of plasma-facing components and inspection in the reactor vessel. The system must be compatible with the vessel environment of high gamma radiation (10{sup 4} Gy/h), ultra-high-vacuum (10{sup {minus}8} torr), and elevated temperature (200 C). The high radiation requires that the system be remotely deployed. A coherent frequency modulated laser radar-based system will be integrated with a remotely operated deployment mechanism to meet these requirements. The metrology/viewing 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 a biological shield. The deployment mechanism will be a mast-like positioning system. Radiation-damage tests will be conducted on critical sensor components at Oak Ridge National Laboratory to determine threshold damage levels and effects on data transmission. This paper identifies the requirements for International Thermonuclear Experimental Reactor metrology and viewing and describes a remotely operated precision ranging and surface mapping system.

  19. A non-contacting vertical alignment system for mass properties measuring instruments

    SciTech Connect

    James, G.H. III; Suazo, J.E.; Varga, R.C.

    1993-11-01

    A non-contact system for alignment of objects on mass properties measuring instruments is described. Test parts can be aligned to within the capabilities of the user and the fixture to make the adjustments. The current implementation can align objects to less than .001 inches at two points with final requested adjustments of a few ten-thousands of an inch. The non-contact capability allows the alignment of objects which are too compliant or fragile for traditional contacting measurement methods. Also, this system allows the definition of a reference axis on objects which are not perfectly symmetric. The reference axis is defined at the top of the object by an appropriate marker and defined at the bottom by a best fit circle through the surface at a specified height. A general description of the hardware, procedures, and results are presented for the non-user. Appendices which contain a complete description of the software, usage, and mathematical implementation are provided for the reader who is interested in using or further developing the system.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. [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. PMID:23198427

  5. 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.

  6. 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.

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

    NASA Astrophysics Data System (ADS)

    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/cm2. 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.

  8. 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

  9. Laser Surveillance System for Spent Fuel

    SciTech Connect

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

    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.

  10. 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.

  11. 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.

  12. Automated sample mounting and alignment system for biological crystallography at a synchrotron source.

    PubMed

    Snell, Gyorgy; Cork, Carl; Nordmeyer, Robert; Cornell, Earl; Meigs, George; Yegian, Derek; Jaklevic, Joseph; Jin, Jian; Stevens, Raymond C; Earnest, Thomas

    2004-04-01

    High-throughput data collection for macromolecular crystallography requires an automated sample mounting and alignment 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. PMID:15062077

  13. BECOLA Beam Line Construction and Laser System

    NASA Astrophysics Data System (ADS)

    Pedicini, Eowyn; Minamisono, Kei; Barquest, Brad; Bollen, Georg; Klose, Andrew; Mantica, Paul; Morrissey, Dave; Ringle, Ryan; Schwarz, Stefan; Vinnikova, Sophia

    2010-11-01

    The BECOLA (BEam COoler and LAser spectroscopy) facility is being installed at NSCL for experiments on radioactive nuclides.ootnotetextK. Minamisono et al, Proc. Inst. Nucl. Theory 16, 180 (2009). Low energy ion beams will be cooled/bunched in an RFQ ion trap and then extracted to a max of 60 kV. The ion beam will be neutralized through a charge exchange cell (CEC), and remaining ions will be removed by a deflector and collected in a Faraday cup. Collinear laser spectroscopy will be used to measure the atomic hyperfine structure, and nuclear properties will be extracted. The assembly, vacuum testing, and optical alignment of the CEC have been completed and the ion deflector and Faraday cup were also assembled. Stabilization of the Ti:sapphire laser to be used for spectroscopy is achieved through a feedback loop using a precision wavelength meter that is calibrated by a stabilized He-Ne laser. Coupling the He-Ne laser into a single-mode optical fiber was optimized for stable operation of the feedback loop. Finally, a wall chart of nuclear moments was prepared to view trends in μ and Q for nuclear ground states for planning future measurements.

  14. 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. PMID:24514774

  15. 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

  16. Method for auto-alignment of digital optical phase conjugation systems based on digital propagation

    PubMed Central

    Jang, Mooseok; Ruan, Haowen; Zhou, Haojiang; Judkewitz, Benjamin; Yang, Changhuei

    2014-01-01

    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

  17. 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.

  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. PMID:24977504

  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. 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.

  1. Fibre laser component technology for 2-micron laser systems

    NASA Astrophysics Data System (ADS)

    Stevens, G.; Robertson, A.

    2014-05-01

    We report on recent developments in fibre laser component technology for use in 2-micron laser systems. A range of `building block' components has been built to allow novel fibre laser architectures that exploit the advantages of fibre lasers based on Thulium and Holmium active fibres. Fibre lasers operating around 2-microns are becoming widely used in an increasing number of applications, which is driving the need for components that can operate reliably at high powers and also integrate easily with other components. To that end, we have designed and built a range of fused fibre, acousto-optic and magneto-optic devices that can be readily integrated into a range of novel fibre laser systems. Research has been carried out into improving fused fibre technology for components operating at 2um wavelengths. Side-coupled feed through combiners have been developed with signal losses as low as 0.02dB and kilowatt level end-coupled pump couplers. Alongside this a range of taps, splitters and WDMs have been developed which allows for the implementation of a variety of laser architectures. Optical isolators based on new Faraday materials have been developed, providing over 30dB isolation, low insertion loss and 30W power handling in a fibre-in, fibre-out version. New cell designs and materials for Acousto-Optic devices have been researched leading to the development of fibre-coupled Acousto-Optic Modulators (AOM) and allows for the realisation of all fibre Thulium and Holmium Q-switched and pulsed fibre lasers. Novel Acousto-Optic Tunable Filters (AOTF) designs have been realised to produce narrow resolution AOTFs and zero-shift AOTFs.

  2. 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.

  3. Aligned carbon nanotubes catalytically grown on iron-based nanoparticles obtained by laser-induced CVD

    NASA Astrophysics Data System (ADS)

    Le Normand, F.; Cojocaru, C. S.; Ersen, O.; Legagneux, P.; Gangloff, L.; Fleaca, C.; Alexandrescu, R.; Dumitrache, F.; Morjan, I.

    2007-12-01

    Iron-based nanoparticles are prepared by a laser-induced chemical vapor deposition (CVD) process. They are characterized as body-centered Fe and Fe 2O 3 (maghemite/magnetite) particles with sizes ≤5 and 10 nm, respectively. The Fe particles are embedded in a protective carbon matrix. Both kind of particles are dispersed by spin-coating on SiO 2/Si(1 0 0) flat substrates. They are used as catalyst to grow carbon nanotubes by a plasma- and filaments-assisted catalytic CVD process (PE-HF-CCVD). Vertically oriented and thin carbon nanotubes (CNTs) were grown with few differences between the two samples, except the diameter in relation to the initial size of the iron particles, and the density. The electron field emission of these samples exhibit quite interesting behavior with a low turn-on voltage at around 1 V/μm.

  4. 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.

  5. Laser Image Contrast Enhancement System

    NASA Technical Reports Server (NTRS)

    Kurtz, Robert L. (Inventor); Holmes, Richard R. (Inventor); Witherow, William K. (Inventor)

    2002-01-01

    An optical image enhancement system provides improved image contrast in imaging of a target in high temperature surroundings such as a furnace. The optical system includes a source of vertically polarized light such as laser and a beam splitter for receiving the light and directing the light toward the target. A retardation plate is affixed to a target-facing surface of the beam splitter and a vertical polarizer is disposed along a common optical path with the beam splitter between the retardation plate and the target. A horizontal polarizer disposed in the common optical path, receives light passing through a surface of the beam splitter opposed to the target-facing surface. An image detector is disposed at one end of the optical path. A band pass filter having a band pass filter characteristic matching the frequency of the vertically polarized light source is disposed in the path between the horizontal polarizer and the image detector. The use of circular polarization, together with cross polarizers, enables the reflected light to be passed to the detector while blocking thermal radiation.

  6. Study on short distance laser ranging system

    NASA Astrophysics Data System (ADS)

    Bao, Jianan; Li, Jicheng; Zhang, Cong

    2015-02-01

    Laser ranging technology is an industrial non contact measuring technology. With the rapidly development of electronics and optical technology, the measuring precision has been improved continuously. In this paper, a simple structure measuring system which based on laser triangulation measuring theory, was built. The system consist of single point laser and CMOS receiver, its measuring range is from 90mm to 110mm. In order to get a higher position accuracy of light spot, gauss cumulative method was used in this paper. For realize the precision system calibration, a linear calibration method was introduced. The experiment shows that the system get a measuring precision of 10um.

  7. 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

  8. Medical laser system WOLF-1

    NASA Astrophysics Data System (ADS)

    Wolf, Leszek; Peszynski-Drews, Cezary; Szydlak, Jerzy; Nowakowski, Wlodzimierz

    2000-11-01

    In CDTL PL a set of lasers was installed with irradiation connected to treatment and operation rooms by energetic optical fibers. The introduction of irradiation of particular lasers into fiberguides is controlled by the computer. Fiber couplers were installed on the entrance of transmission fiberguides, and they were connected to optical fibers with different end-pieces according to medical needs.

  9. 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.

  10. 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.

  11. Smithsonian Astrophysical Observatory laser tracking systems

    NASA Technical Reports Server (NTRS)

    Pearlman, M. R.; Lanham, N. W.; Lehr, C. G.; Wohn, J.

    1977-01-01

    The four SAO laser satellite-ranging systems, located in Brazil, Peru, Australia, and Arizona, have been in operation for more than five years and have provided ranging data at accuracy levels of a meter or better. The paper examines system hardware (laser transmitter, the electronics, mount, photoreceiver, minicomputer, and station timing) and software (prediction program, calibration programs, and data handling and quick-look programs) and also considers calibration, station operation, and system performance.

  12. 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

  13. Laser Mégajoule synchronization system

    NASA Astrophysics Data System (ADS)

    Luttmann, Michel; Pastor, Jean François; Drouet, Vincent; Prat, Michel; Raimbourg, Jo"l.; Adolf, Alain

    2011-03-01

    This paper describes the synchronisation system under development on the Laser Mégajoule (LMJ) in order to synchronize the laser quads on the target to better than 40ps rms. Our architecture is based on a Timing System (TS) which delivers trigger signals with jitter down to 15ps rms coupled with an ultra precision timing system with 5ps rms jitter. In addition to TS, a sensor placed at the target chamber center measures the arrival times of the 3ω nano joule laser pulses generated by front end shots.

  14. 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.

  15. 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.

  16. Space Applications Industrial Laser System (SAILS)

    NASA Astrophysics Data System (ADS)

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

    1993-10-01

    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.

  17. 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.

  18. 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...

  19. 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...

  20. Computerized "drag-and-drop" alignment of GPC-based optical micromanipulation system.

    PubMed

    Dam, Jeppe Seidelin; Rodrigo, Peter John; Perch-Nielsen, Ivan R; Alonzo, Carlo Amadeo; Glückstad, Jesper

    2007-02-19

    In the past, aligning the counterpropagating beams in our 3D real-time generalized phase contrast (GPC) trapping system has been a task requiring moderate skills and prior experience with optical instrumentation. A ray transfer matrix analysis and computer-controlled actuation of mirrors, objective, and sample stage has made this process user friendly. The alignment procedure can now be done in a very short time with just a few drag-and-drop tasks in the user-interface. The future inclusion of an image recognition algorithm will allow the alignment process to be executed completely without any user interaction. An automated sample loading tray with a loading precision of a few microns has also been added to simplify the switching of samples under study. These enhancements have significantly reduced the level of skill and experience required to operate the system, thus making the GPC-based micromanipulation system more accessible to people with little or no technical expertise in optics. PMID:19532431

  1. Laser Threat Analysis System (LTAS)

    NASA Astrophysics Data System (ADS)

    Pfaltz, John M.; Richardson, Christina E.; Ruiz, Abel; Barsalou, Norman; Thomas, Robert J.

    2002-11-01

    LTAS is a totally integrated modeling and simulation environment designed for the purpose of ascertaining the susceptibility of Air Force pilots and air crews to optical radiation threats. Using LTAS, mission planners can assess the operational impact of optically directed energy weapons and countermeasures. Through various scenarios, threat analysts are able to determine the capability of laser threats and their impact on operational missions including the air crew's ability to complete their mission effectively. Additionally, LTAS allows the risk of laser use on training ranges and the requirement for laser protection to be evaluated. LTAS gives mission planners and threat analysts complete control of the threat environment including threat parameter control and placement, terrain mapping (line-of-site), atmospheric conditions, and laser eye protection (LEP) selection. This report summarizes the design of the final version of LTAS, and the modeling methodologies implemented to accomplish analysis.

  2. 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.

  3. 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.

  4. Research on Initial Alignment and Self-Calibration of Rotary Strapdown Inertial Navigation Systems

    PubMed Central

    Gao, Wei; Zhang, Ya; Wang, Jianguo

    2015-01-01

    The errors of inertial sensors affect the navigation accuracy of the strapdown inertial navigation system (SINS) and are accumulated over time in nature. In order to continuously maintain the high navigation accuracy of vehicles for a long time period, an initial alignment and self-calibration is necessary after the SINS starts. Additionally, the observability analysis is one of the key techniques during the initial alignment and self-calibration process. For marine systems, the observability of inertial sensor errors is extremely low, as their motion states are always slow. Therefore, studying the rotating SINS is urgent. Since traditional analysis methods have their limitations, the global observation analysis method was used in this paper. On the basis of this method, the relationship between the observability and the kinestate of the rotating SINS has been established. After the discussion about the factors that affect the observability in detail, the design principle of the initial alignment and self-calibration rotating scheme, which is appropriate for marine systems, id proposed. With the proposed principle, a novel initial alignment and self-calibration method, named the eight-position rotating scheme, is designed. Simulations and experiments are carried out to verify its performance. The results have shown that compared with other rotating schemes and the static state, the estimated accuracy of the eight-position scheme rotating about axes x and y was the best, and the position error was significantly reduced with this new rotating scheme. The feasibility and effectiveness of the proposed design principle and the rotating scheme were verified. PMID:25647743

  5. 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.

  6. 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.

  7. An improved instantaneous laser Doppler velocity system

    NASA Astrophysics Data System (ADS)

    Desio, Charles V.; Olcmen, Semih; Schinetsky, Philip

    2016-02-01

    In this paper, improvements made on a single velocity component instantaneous laser Doppler velocimetry (ILDV) system are detailed. The ILDV system developed in this research effort is capable of measuring a single velocity component at a rate as high as two megahertz. The current system accounts for the effects of the laser intensity variation on the measured velocity and eliminates the use of a Pockels cell used in previous ILDV systems. The system developed in the current effort was tested using compressible, subsonic jet flows. The ILDV system developed would be most beneficial where a high data capture rate is needed such as in shock tubes, and high-speed wind tunnels.

  8. 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.

  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. The TileCal Laser Calibration System

    NASA Astrophysics Data System (ADS)

    Giangiobbe, Vincent; On Behalf Of The Atlas Tile Calorimeter Group

    TileCal is the central hadronic calorimeter of the ATLAS detector operating at LHC. It is a sampling calorimeter whose active material is made of scintillating plastic tiles. Scintillation light is read by photomultipliers. A Laser system is used to monitor their gain stability. During dedicated calibration runs the Laser system sends via long optical fibers, a monitored amount of light simultaneously to all the ≈10000 photomultipliers of TileCal. This note describes two complementary methods to measure the stability of the photomultipliers gain using the Laser calibration runs. The results of validation tests are presented for both methods and theirrespective performances and limitations are discussed.

  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. An autocollimator alignment system for a Schwarzschild-Couder Cherenkov telescope

    NASA Astrophysics Data System (ADS)

    Griffiths, S. T.; Kaaret, P.; Smith, E.

    2016-04-01

    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.

  13. 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.

  14. 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.

  15. Infrared detectors and lasers operating in the 3-12 μm range using band-gap engineered structures with type II band-gap alignment

    NASA Astrophysics Data System (ADS)

    Swaminathan, Venkataraman; Little, John W.; Tober, Richard L.

    2006-02-01

    The Type II broken band-gap alignment in semiconductor structures wherein the conduction band minimum is in one semiconductor (e.g., InAs) and the valence band maximum is in another (e.g., GaInSb) offers certain unique advantages which can be utilized to realize band-gap engineered novel quantum electro-optic devices such as lasers and detectors. The advantages of the type II structures include reduced Auger recombination, extending the effective band-gap energy of materials wherein type I band-gap alignment would give rise to difficulties such as miscibility gap. In this paper we describe the work carried out at the Army Research Laboratory on type II semiconductor quantum electro-optic devices such as IR lasers and detectors operating in the 3-12 μm range. Specifically we will cover the progress made in GaSb based type II strained layer superlattice IR detectors and Interband Cascade IR Lasers. We will also present our recent work in self-assembled quantum dots which have type II band-gap alignment with the matrix material in which the dots are embedded.

  16. Solid state laser systems for space application

    NASA Technical Reports Server (NTRS)

    Kay, Richard B.

    1994-01-01

    Since the last report several things have happened to effect the research effort. In laser metrology, measurements using Michelson type interferometers with an FM modulated diode laser source have been performed. The discrete Fourier transform technique has been implemented. Problems associated with this technique as well as the overall FM scheme were identified. The accuracy of the technique is not at the level we would expect at this point. We are now investigating the effect of various types of noise on the accuracy as well as making changes to the system. One problem can be addressed by modifying the original optical layout. Our research effort was also expanded to include the assembly and testing of a diode pumped\\Nd:YAG laser pumped\\Ti sapphire laser for possible use in sounding rocket applications. At this stage, the diode pumped Nd:YAG laser has been assembled and made operational.

  17. Nano-positioning control of 5-DOF manipulator for alignment of condenser in soft x-ray microscopy system

    NASA Astrophysics Data System (ADS)

    Kim, Kyu Gyeom; Kim, Jae Hee; Min, Jong Hwan; Kim, Kyong Woo; Kwon, Young Man; Min, Jin Young; Yoon, Kwon Ha

    2005-08-01

    This paper presents a method of a nano-positioning control for the high precision focusing of a doubled ellipsoidal condenser reflective mirror using 5-axis manipulator. We have developed the compact vertical type of soft X-ray microscopy system with 50nm resolution for biomedical application. This microscopy system is composed of a laser plasma x-ray source, doubled ellipsoidal condenser reflective optics, diffractive zone plate optics and MCP coupled with CCD to record an x-ray image. The X-ray source was focused on a sample by a doubled ellipsoidal condenser reflective mirror. X-ray source focusing will increase the photon density in the object plane and is very important to approach high resolution imaging. Required degree of freedom (DOF) of optics aligner in X-ray microscope is dependent on the kind of optics, but generally 5-DOF is needed. We used 5-axis manipulator that consists of three linear motions (X, Y and Z) and two tilting motions (θx, θy). A linear translation stage is adopted a kind of DC motor with a linear resolution 50nm and travel range of 5mm. The mechanism was controlled with PID controller augmented with closed feedback loop for precision control. A two axis tilt stage is employed a design resolution of 0.23μrad and tilt range of +/-7deg. We have designed 5-axis manipulator for the precision position control of condenser mirror optics and have developed to control algorithm by inverse kinematics. The performance of the proposed 5-DOF manipulator is evaluated by using a laser interferometer system with two plane mirror reflectors. The experimental results are depicted in this paper.

  18. 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.

  19. 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.

  20. Laser Safety and Hazardous Analysis for the ARES (Big Sky) Laser System

    SciTech Connect

    AUGUSTONI, ARNOLD L.

    2003-01-01

    A laser safety and hazard analysis was performed for the ARES 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 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.

  1. 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

  2. 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

  3. Optical design of laser transmission system

    NASA Astrophysics Data System (ADS)

    Zhang, Yulan; Feng, Jinliang; Li, Yongliang; Yang, Jiandong

    1998-08-01

    This paper discusses a design of optical transfer system used in carbon-dioxide laser therapeutic machine. The design of this system is according to the requirement of the therapeutic machine. The therapeutic machine requires the movement of laser transfer system is similar to the movement of human beings arms, which possesses 7 rotating hinges. We use optical hinges, which is composed of 45 degree mirrors. Because the carbon-dioxide laser mode is not good, light beam diameter at focus and divergence angle dissemination are big, we use a collecting lens at the transfer system output part in order to make the light beam diameter at focus in 0.2 to approximately 0.3 mm. For whole system the focus off-axis error is less than 0.5 mm, the transfer power consumption is smaller than 10%. The system can move in three dimension space freely and satisfies the therapeutic machine requirement.

  4. 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.

  5. 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

  6. 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.

  7. Scanning afocal laser velocimeter projection lens system

    NASA Technical Reports Server (NTRS)

    Rhodes, D. B. (Inventor)

    1982-01-01

    A method and apparatus for projecting and focusing parallel laser light beams from a laser doppler velocimeter on a target area are described. The system includes three lenses. Two lenses work together as a fixed afocal lens combination. The third lens is a movable scanning lens. Parallel laser beams travel from the velocimeter through the scanning lens and through the afocal lens combination and converge, i.e., are focused, somewhere beyond. Moving the scanning lens relative to the fixed afocal combination results in a scanning of the focus area along the afocal combination's optical axis.

  8. Software development for the Hobby-Eberly Telescope's Segment Alignment Maintenance System using LabVIEW

    NASA Astrophysics Data System (ADS)

    Hall, Drew; Ly, William; Howard, Richard T.; Weir, John T.; Rakoczy, John M.

    2002-12-01

    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.

  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. Development of an ion beam alignment system for real-time scanning tunneling microscope observation of dopant-ion irradiation

    SciTech Connect

    Kamioka, Takefumi; Sato, Kou; Kazama, Yutaka; Watanabe, Takanobu; Ohdomari, Iwao

    2008-07-15

    An ion beam alignment system has been developed in order to realize real-time scanning tunneling microscope (STM) observation of 'dopant-ion' irradiation that has been difficult due to the low emission intensity of the liquid-metal-ion-source (LMIS) containing dopant atoms. The alignment system is installed in our original ion gun and STM combined system (IG/STM) which is used for in situ STM observation during ion irradiation. By using an absorbed electron image unit and a dummy sample, ion beam alignment operation is drastically simplified and accurized. We demonstrate that sequential STM images during phosphorus-ion irradiation are successfully obtained for sample surfaces of Si(111)-7x7 at room temperature and a high temperature of 500 deg. C. The LMIS-IG/STM equipped with the developed ion beam alignment system would be a powerful tool for microscopic investigation of the dynamic processes of ion irradiation.

  11. Lasers and space optical systems study

    NASA Astrophysics Data System (ADS)

    Giuliano, Concetto; Annaballi, Angela L.

    1998-01-01

    The Air Force and other government organizations have considered the application of space-based lasers since the early 1970s. Recent studies have identified the enormous potential of lasers and optical systems in space to support the Full-Spectrum Dominance envisioned by the Joint Chiefs of Staff in ``Joint Vision 2010.'' The Air Force Research Laboratory has undertaken the LAsers and S_pace O_ptical S_ystems (LASSOS) Study to examine in detail how space lasers and optics (defined as any laser system based in space or any terrestrial-based laser whose beam transits space) could best be used to satisfy this critical need. This twelve-month study will identify promising technology concepts for space laser/optic systems, develop system concepts based on these technologies with special emphasis on systems capable of performing multiple missions, assess how well these systems can accomplish operational tasks in a quantitative manner, and design technology development roadmaps for selected concepts. Since work on the study had commenced only days before the publication deadline, this manuscript is necessarily limited to a description of the background, motivation, and organization of the study. The ``Concept Definition'' phase of the study is scheduled to be completed by the time of the STAIF conference. By that time, study participants will have identified key concepts that best satisfy criteria for timely and cost-effective augmentation of combat capability. A final report, which will be made available to authorized recipients, will be written after completion of the study in August 1998.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Synthesis of vertically aligned carbon nanofibers for interfacing with live systems

    SciTech Connect

    Melechko, Anatoli Vasilievich; Desikan, Ramya; McKnight, Timothy E; Klein, Kate L; Rack, P. D.

    2009-01-01

    The ability to synthesize carbon nanofibers with a high degree of control over their geometry, location, and structure via catalytic plasma-enhanced chemical vapor deposition has expanded the possibility of new applications. The nanoscale dimensions and high aspect ratio of vertically aligned carbon nanofibers (VACNFs), along with favorable physical and chemical characteristics, has provided a nanostructured material with properties that are well-suited for interfacing with live cells and tissues. This review surveys the aspects of synthesis, integration, and functionalization of VACNFs, followed by examples of how VACNFs have been used to interface with live systems for a variety of advanced nanoscale biological applications.

  18. 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.

  19. 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

  20. Use of the Abbe sine condition to quantify alignment aberrations in optical imaging systems

    NASA Astrophysics Data System (ADS)

    Burge, James H.; Zhao, Chunyu; Lu, Sheng Huei

    2010-08-01

    Violation of Abbe's sine condition is well-known to cause coma in axisymmetric imaging systems, and generally any offense against the sine condition (OSC) will cause aberrations that have linear dependence on the field angle. A well-corrected imaging system must obey the Abbe sine condition. A misaligned optical system can have particular forms of the OSC which are evaluated here. The lowest order non-trivial effects of misalignment have quadratic pupil dependence which causes a combination of astigmatism and focus that have linear field dependence. Higher order terms can arise from complex systems, but the effects of misalignment are nearly always dominated by the lowest order effects which can be fully characterized by measuring images on axis and the on-axis offense against the sine condition. By understanding the form of the on-axis images and the OSC, the state of alignment can be determined.

  1. 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.

  2. 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.

  3. Neogene-Quaternary Volcanic Alignments in the Transantarctic Mountains and West Antarctic Rift System of Southern Victoria Land, Antarctica

    NASA Astrophysics Data System (ADS)

    Paulsen, T. S.; Wilson, T. J.

    2004-12-01

    Neogene-Quaternary volcanism in southern Victoria Land, Antarctica, produced the Erebus Volcanic Province, a suite of alkaline volcanic rocks that extend from the Transantarctic Mountains rift-flank uplift to offshore localities within the West Antarctic rift system. We are mapping volcanic vent patterns in the province to detect alignments indicative of stress/strain patterns during rift evolution. In the southern sector of the Erebus Volcanic Province in the Royal Society Range Block of the Transantarctic Mountains, mapping shows that elliptical scoria cones, fissures, dikes, and linear vent arrays define volcanic alignments that have a dominant NNE trend, with subsidiary WNW trends. Age data for the alignments suggest that this pattern persisted from 14.6 to 0.25 Ma. We are currently completing mapping along an east-west transect crossing the rift margin, and results obtained so far within the rift region indicate a similar pattern of alignments. On the northern flank of Mount Morning, a large volcano just to the east of the Royal Society Range, elliptical scoria cones and linear vent arrays define volcanic alignments that have a dominant NE trend, with a subsidiary NNW trend. Available age data suggest that many of these cone alignments may be of Quaternary age. At Brown Peninsula, further east from the rift flank, cone alignments trend NNE and available ages range from 2 to 3 Ma. To the east of Brown Peninsula, cone alignments trend NW at Black Island, but are of uncertain age; age data on Black Island range from 11 to 3.4 Ma. At White Island, the farthest east into the rift, cone alignments trend NNE and available age data suggest volcanism as young as 0.2 Ma. Although some differences in cone alignment trends are apparent between the rift flank and the rift system across our transect, both regions appear to be dominated by NE trending alignments, which implies a WNW to NW minimum horizontal stress (Shmin) direction. This is oblique to the ENE Shmin Cape

  4. 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. PMID:20068746

  5. 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)

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. Laser Systems For Use With Airborne Platforms

    NASA Astrophysics Data System (ADS)

    Jepsky, Joseph

    1984-10-01

    This paper describes a family of airborne laser systems in use for terrain profiling, surveying, mapping, altimetry, collision avoidance and shipboard landing systems using fixed and rotary wing aircraft as the platforms. The laser altimeter has also been used in systems compatible with the Army T-16 and. T-22 carrier missiles (platform). Both pulsed gallium arsenide and Nd:YAG (neodymium-doped, yttrium-aluminum-garnet) laser rangefinders have been used for these applications. All of these systems use ACCI's advanced measurement techniques that permit range accuracies of 8 cm, single shot, 1 cm averaged, to be achieved. Pulse rates up to 4 Khz are employed for airborne profiling. This high data density rate provides 1 data point every 2" along the aircraft flight line at aircraft speed of 500 knots. Scanning modes for some applications are employed. Systems have been integrated with all current inertial navigation systems (Litton, Ferranti and Honeywell), as well as a number of microwave positioning systems. Removal of aircraft motion from the laser range measurements by use of an accelerometer is described. Flight data from a number of program performed by U.S. and Canadian Federal Agencies, in addition to those of commercial surveying and mapping companies are described.

  11. 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.

  12. Starspots and Spin-orbit Alignment in the WASP-4 Exoplanetary System

    NASA Astrophysics Data System (ADS)

    Sanchis-Ojeda, Roberto; Winn, Joshua N.; Holman, Matthew J.; Carter, Joshua A.; Osip, David J.; Fuentes, Cesar I.

    2011-06-01

    We present photometry of four transits of the exoplanet WASP-4b, each with a precision of approximately 500 ppm and a time sampling of 40-60 s. We have used the data to refine the estimates of the system parameters and ephemerides. During two of the transits we observed a short-lived, low-amplitude anomaly that we interpret as the occultation of a starspot by the planet. We also found evidence for a pair of similar anomalies in previously published photometry. The recurrence of these anomalies suggests that the stellar rotation axis is nearly aligned with the orbital axis, or else the starspot would not have remained on the transit chord. By analyzing the timings of the anomalies we find the sky-projected stellar obliquity to be λ = -1+14 - 12 degrees. This result is consistent with (and more constraining than) a recent observation of the Rossiter-McLaughlin effect. It suggests that the planet migration mechanism preserved the initially low obliquity, or else that tidal evolution has realigned the system. Future applications of this method using data from the CoRoT and Kepler missions will allow spin-orbit alignment to be probed for many other exoplanets. Based on observations with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile.

  13. 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.

  14. PHASE NOISE COMPARISON OF SHORT PULSE LASER SYSTEMS

    SciTech Connect

    Shukui Zhang; Stephen Benson; John Hansknecht; David Hardy; George Neil; Michelle D. Shinn

    2006-08-27

    This paper describes phase noise measurements of several different laser systems that have completely different gain media and configurations including a multi-kW free-electron laser. We will focus on state-of-the-art short pulse lasers, especially drive lasers for photocathode injectors. Phase noise comparison of the FEL drive laser, electron beam and FEL laser output also will be presented.

  15. 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.

  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. 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.

  18. Laser systems for ablative fractional resurfacing.

    PubMed

    Paasch, Uwe; Haedersdal, Merete

    2011-01-01

    Ablative fractional resurfacing (AFR) creates microscopic vertical ablated channels that are surrounded by a thin layer of coagulated tissue, constituting the microscopic treatment zones (MTZs). AFR induces epidermal and dermal remodeling, which raises new possibilities for the treatment of a variety of skin conditions, primarily chronically photodamaged skin, but also acne and burn scars. In addition, it is anticipated that AFR can be utilized in the laser-assisted delivery of topical drugs. Clinical efficacy coupled with minimal downtime has driven the development of various fractional ablative laser systems. Fractionated CO(2) (10,600-nm), erbium yttrium aluminum garnet, 2940-nm and yttrium scandium gallium garnet, 2790-nm lasers are available. In this article, we present an overview of AFR technology, devices and histopathology, and we summarize the current clinical possibilities with AFR incorporating our personal experience. AFR is still in the exploratory era, and systematic investigations of clinical outcomes related to various system settings are needed. PMID:21158542

  19. 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.

  20. Nuclear Powered Laser Driven Plasma Propulsion System

    NASA Astrophysics Data System (ADS)

    Kammash, T.

    A relativistic plasma thruster that could open up the solar system to near-term human exploration is presented. It is based on recent experimental and theoretical research, which show that ultrafast (very short pulse length) lasers can accelerate charged particles to relativistic speeds. In table top-type experiments charge-neutral proton beams containing more than 1014 particles with mean energies of tens of MeV's have been produced when high intensity lasers with femtosecond (10-15 s) pulse lengths are made to strike thin solid targets. When viewed from a propulsion standpoint such systems can produce specific impulses of several million seconds albeit at modest thrusts and require nuclear power systems to drive them. Several schemes are proposed to enhance the thrust and make these systems suitable for manned interplanetary missions. In this paper we set forth the physics principles that make relativistic plasma driven by ultrafast lasers particularly attractive for propulsion applications. We introduce the “Laser Accelerated Plasma Propulsion System” LAPPS, and demonstrate its potential propulsive capability by addressing an interstellar mission to the Oort Cloud, and a planetary mission to Mars. We show that the first can be carried out in a human's lifetime and the second in a matter of months. In both instances we identify the major technological problems that must be addressed if this system is to evolve into a leading contender among the advance propulsion concepts currently under consideration.

  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. 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.

  3. 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)

  4. Starspots And Spin-orbit Alignment In the Wasp-4 Exoplanetary System

    NASA Astrophysics Data System (ADS)

    Sanchis Ojeda, Roberto; Winn, J. N.; Holman, M. J.; Carter, J. A.; Osip, D. J.; Fuentes, C. I.

    2011-05-01

    We present photometry of 4 transits of the exoplanet WASP-4b, each with a precision of approximately 500 ppm and a time sampling of 40-60s. During two of the transits we observed a short-lived, low-amplitude anomaly that we interpret as the occultation of a starspot by the planet. We also find evidence for a pair of similar anomalies in previously published photometry. The recurrence of these anomalies suggests that the stellar rotation axis is nearly aligned with the orbital axis, or else the star spot would not have remained on the transit chord. By analyzing the timings of the anomalies we find the sky-projected stellar obliquity to be 1^{+12}_{-14} degrees. This result is consistent with (and more constraining than) a recent observation of the Rossiter-McLaughlin effect. It suggests that the planet migration mechanism preserved the initially low obliquity, or else that tidal evolution has realigned the system. We discuss future applications of this method using data from the Kepler satellite, which will allow spin-orbit alignment to be probed for many other exoplanets.

  5. 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

  6. 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.

  7. 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.

  8. 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)

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Electronic Subsystems For Laser Communication System

    NASA Technical Reports Server (NTRS)

    Long, Catherine; Maruschak, John; Patschke, Robert; Powers, Michael

    1992-01-01

    Electronic subsystems of free-space laser communication system carry digital signals at 650 Mb/s over long distances. Applicable to general optical communications involving transfer of great quantities of data, and transmission and reception of video images of high definition.

  19. 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.

  20. 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.