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Sample records for laser diffraction system

  1. DIFFRACTION SYNCHRONIZATION OF LASERS,

    Science.gov (United States)

    semiconductor lasers while suppressing parasitic generation in the plane of the mirror. The diffraction coupling coefficient of open resonators is calculated, and the stability conditions of the synchronized system is determined.

  2. Diffraction measurements for LASL's Antares Laser System. Informal report

    International Nuclear Information System (INIS)

    Sollid, J.E.

    1978-08-01

    Beam diffraction, both in the near field and the far field, was studied to assess the effect of the 12-segmented annular exit window proposed for the Antares laser system. The near-field studies indicate that diffraction spillover effects are less than 5% and that hot spots in the aperture are not apt to exceed the design flux level of 2 J/cm 2 . The far-field investigation has shown that the segments in the annulus may be considered independently and, therefore, energy and intensity add up incoherently. Also, the total intensity distribution is well approximated by 12 times the intensity distribution in a circular aperture with the same area as a single sector

  3. Beam Size Measurement by Optical Diffraction Radiation and Laser System for Compton Polarimeter

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chuyu [Peking Univ., Beijing (China)

    2012-12-31

    difficulty of diagnostics. For most cases, intercepting measurements are no longer acceptable, and nonintercepting method like synchrotron radiation monitor can not be applied to linear accelerators. The development of accelerator technology asks for simutanous diagnostics innovations, to expand the performance of diagnostic tools to meet the requirements of the next generation accelerators. Diffraction radiation and inverse Compton scattering are two of the most promising techniques, their nonintercepting nature avoids perturbance to the beam and damage to the instrumentation. This thesis is divided into two parts, beam size measurement by optical diffraction radiation and Laser system for Compton polarimeter. Diffraction radiation, produced by the interaction between the electric field of charged particles and the target, is related to transition radiation. Even though the theory of diffraction radiation has been discussed since 1960s, there are only a few experimental studies in recent years. The successful beam size measurement by optical diffraction radiation at CEBAF machine is a milestone: First of all, we have successfully demonstrated diffraction radiation as an effective nonintercepting diagnostics; Secondly, the simple linear relationship between the diffraction radiation image size and the actual beam size improves the reliability of ODR measurements; And, we measured the polarized components of diffraction radiation for the first time and I analyzed the contribution from edge radiation to diffraction radiation.

  4. Beam Size Measurement by Optical Diffraction Radiation and Laser System for Compton Polarimeter

    International Nuclear Information System (INIS)

    Liu, Chuyu

    2012-01-01

    difficulty of diagnostics. For most cases, intercepting measurements are no longer acceptable, and nonintercepting method like synchrotron radiation monitor can not be applied to linear accelerators. The development of accelerator technology asks for simutanous diagnostics innovations, to expand the performance of diagnostic tools to meet the requirements of the next generation accelerators. Diffraction radiation and inverse Compton scattering are two of the most promising techniques, their nonintercepting nature avoids perturbance to the beam and damage to the instrumentation. This thesis is divided into two parts, beam size measurement by optical diffraction radiation and Laser system for Compton polarimeter. Diffraction radiation, produced by the interaction between the electric field of charged particles and the target, is related to transition radiation. Even though the theory of diffraction radiation has been discussed since 1960s, there are only a few experimental studies in recent years. The successful beam size measurement by optical diffraction radiation at CEBAF machine is a milestone: First of all, we have successfully demonstrated diffraction radiation as an effective nonintercepting diagnostics; Secondly, the simple linear relationship between the diffraction radiation image size and the actual beam size improves the reliability of ODR measurements; And, we measured the polarized components of diffraction radiation for the first time and I analyzed the contribution from edge radiation to diffraction radiation

  5. High-Average-Power Diffraction Pulse-Compression Gratings Enabling Next-Generation Ultrafast Laser Systems

    Energy Technology Data Exchange (ETDEWEB)

    Alessi, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-11-01

    Pulse compressors for ultrafast lasers have been identified as a technology gap in the push towards high peak power systems with high average powers for industrial and scientific applications. Gratings for ultrashort (sub-150fs) pulse compressors are metallic and can absorb a significant percentage of laser energy resulting in up to 40% loss as well as thermal issues which degrade on-target performance. We have developed a next generation gold grating technology which we have scaled to the petawatt-size. This resulted in improvements in efficiency, uniformity and processing as compared to previous substrate etched gratings for high average power. This new design has a deposited dielectric material for the grating ridge rather than etching directly into the glass substrate. It has been observed that average powers as low as 1W in a compressor can cause distortions in the on-target beam. We have developed and tested a method of actively cooling diffraction gratings which, in the case of gold gratings, can support a petawatt peak power laser with up to 600W average power. We demonstrated thermo-mechanical modeling of a grating in its use environment and benchmarked with experimental measurement. Multilayer dielectric (MLD) gratings are not yet used for these high peak power, ultrashort pulse durations due to their design challenges. We have designed and fabricated broad bandwidth, low dispersion MLD gratings suitable for delivering 30 fs pulses at high average power. This new grating design requires the use of a novel Out Of Plane (OOP) compressor, which we have modeled, designed, built and tested. This prototype compressor yielded a transmission of 90% for a pulse with 45 nm bandwidth, and free of spatial and angular chirp. In order to evaluate gratings and compressors built in this project we have commissioned a joule-class ultrafast Ti:Sapphire laser system. Combining the grating cooling and MLD technologies developed here could enable petawatt laser systems to

  6. Electro-optic diffraction grating tuned laser

    International Nuclear Information System (INIS)

    Hughes, R.S.

    1975-01-01

    An electro-optic diffraction grating tuned laser comprising a laser medium, output mirror, retro-reflective grating and an electro-optic diffraction grating beam deflector positioned between the laser medium and the reflective diffraction grating is described. An optional angle multiplier may be used between the electro-optic diffraction grating and the reflective grating. (auth)

  7. Beam delivery system with a non-digitized diffractive beam splitter for laser-drilling of silicon

    Science.gov (United States)

    Amako, J.; Fujii, E.

    2016-02-01

    We report a beam-delivery system consisting of a non-digitized diffractive beam splitter and a Fourier transform lens. The system is applied to the deep-drilling of silicon using a nanosecond pulse laser in the manufacture of inkjet printer heads. In this process, a circularly polarized pulse beam is divided into an array of uniform beams, which are then delivered precisely to the process points. To meet these requirements, the splitter was designed to be polarization-independent with an efficiency>95%. The optical elements were assembled so as to allow the fine tuning of the effective overall focal length by adjusting the wavefront curvature of the beam. Using the system, a beam alignment accuracy ofbeam array and the throughput was substantially improved (10,000 points on a silicon wafer drilled in ~1 min). This beam-delivery scheme works for a variety of laser applications that require parallel processing.

  8. Diffraction efficiency enhancement of femtosecond laser-engraved diffraction gratings due to CO2 laser polishing

    International Nuclear Information System (INIS)

    Choi, Hun-Kook; Jung, Deok; Sohn, Ik-Bu; Noh, Young-Chul; Lee, Yong-Tak; Kim, Jin-Tae; Ahsan, Shamim

    2014-01-01

    This research demonstrates laser-assisted fabrication of high-efficiency diffraction gratings in fused-silica glass samples. Initially, femtosecond laser pulses are used to engrave diffraction gratings on the glass surfaces. Then, these micro-patterned glass samples undergo CO 2 laser polishing process. unpolished diffraction gratings encoded in the glass samples show an overall diffraction efficiency of 18.1%. diffraction gratings imprinted on the glass samples and then polished four times by using a CO 2 laser beam attain a diffraction efficiency of 32.7%. We also investigate the diffraction patterns of the diffraction gratings encoded on fused-silica glass surfaces. The proposed CO 2 laser polishing technique shows great potential in patterning high-efficiency diffraction gratings on the surfaces of various transparent materials.

  9. Switching waves dynamics in optical bistable cavity-free system at femtosecond laser pulse propagation in semiconductor under light diffraction

    Science.gov (United States)

    Trofimov, Vyacheslav A.; Egorenkov, Vladimir A.; Loginova, Maria M.

    2018-02-01

    We consider a propagation of laser pulse in a semiconductor under the conditions of an occurrence of optical bistability, which appears due to a nonlinear absorption of the semiconductor. As a result, the domains of high concentration of free charged particles (electrons and ionized donors) occur if an intensity of the incident optical pulse is greater than certain intensity. As it is well-known, that an optical beam must undergo a diffraction on (or reflection from) the domains boundaries. Usually, the beam diffraction along a coordinate of the optical pulse propagation does not take into account by using the slowly varying envelope approximation for the laser pulse interaction with optical bistable element. Therefore, a reflection of the beam from the domains with abrupt boundary does not take into account under computer simulation of the laser pulse propagation. However, the optical beams, reflected from nonhomogeneities caused by the domains of high concentration of free-charged particles, can essentially influence on a formation of switching waves in a semiconductor. We illustrate this statement by computer simulation results provided on the base of nonlinear Schrödinger equation and a set of PDEs, which describe an evolution of the semiconductor characteristics (concentrations of free-charged particles and potential of an electric field strength), and taking into account the longitudinal and transverse diffraction effects.

  10. Remote Laser Diffraction PSD Analyzer

    International Nuclear Information System (INIS)

    Batcheller, T.A.; Huestis, G.M.; Bolton, S.M.

    2000-01-01

    Particle size distribution (PSD) analysis of radioactive slurry samples were obtained using a modified off-the-shelf classical laser light scattering particle size analyzer. A Horiba Instruments Inc. Model La-300 PSD analyzer, which has a 0.1 to 600 micron measurement range, was modified for remote application in a hot cell (gamma radiation) environment. The general details of the modifications to this analyzer are presented in this paper. This technology provides rapid and simple PSD analysis, especially down in the fine and microscopic particle size regime. Particle size analysis of these radioactive slurries down in this smaller range was not achievable - making this technology far superior than the traditional methods used previously. Remote deployment and utilization of this technology is in an exploratory stage. The risk of malfunction in this radiation environment is countered by gaining of this tremendously useful fundamental engineering data. Successful acquisition of this data, in conjunction with other characterization analyses, provides important information that can be used in the myriad of potential radioactive waste management alternatives

  11. Remote Laser Diffraction PSD Analyzer

    International Nuclear Information System (INIS)

    Batcheller, Thomas Aquinas; Huestis, Gary Michael; Bolton, Steven Michael

    2000-01-01

    Particle size distribution (PSD) analysis of radioactive slurry samples were obtained using a modified ''off-the-shelf'' classical laser light scattering particle size analyzer. A Horiba Instruments Inc. Model La-300 PSD analyzer, which has a 0.1 to 600 micron measurement range, was modified for remote application in a ''hot cell'' (gamma radiation) environment. The general details of the modifications to this analyzer are presented in this paper. This technology provides rapid and simple PSD analysis, especially down in the fine and microscopic particle size regime. Particle size analysis of these radioactive slurries down in this smaller range was not achievable--making this technology far superior than the traditional methods used previously. Remote deployment and utilization of this technology is in an exploratory stage. The risk of malfunction in this radiation environment is countered by gaining of this tremendously useful fundamental engineering data. Successful acquisition of this data, in conjunction with other characterization analyses, provides important information that can be used in the myriad of potential radioactive waste management alternatives

  12. Laser diffraction analysis of colloidal crystals

    Energy Technology Data Exchange (ETDEWEB)

    Sogami, Ikuo S.; Shinohara, Tadatomi; Yoshiyama, Tsuyoshi [Kyoto Sangyo Univ., Department of Physics, Kyoto (Japan)

    2001-10-01

    Laser diffraction analysis is made on crystallization in salt-free aqueous suspensions of highly-charged colloidal particles for semi-dilute specimens of concentration 0.1-10.0 vol%. Kossel diffraction patterns which represent faithfully accurate information on lattice symmetries in the suspensions enable us to investigate the time evolution of colloidal crystals. The results show that the crystallization proceeds by way of the following intermediate phase transitions: two-dimensional hcp structure {yields} random layer structure {yields} layer structure with one sliding degree of freedom {yields} stacking disorder structure {yields} stacking structure with multivariant periodicity {yields} fcc twin structure with twin plane (111) {yields} normal fcc structure {yields} bcc twin structure with twin plane (11-bar2) or (1-bar12) {yields} normal bcc structure. For concentrated suspensions (>2 vol %), the phase transition ceases to proceed at the normal fcc structure. (author)

  13. Laser diffraction analysis of colloidal crystals

    International Nuclear Information System (INIS)

    Sogami, Ikuo S.; Shinohara, Tadatomi; Yoshiyama, Tsuyoshi

    2001-01-01

    Laser diffraction analysis is made on crystallization in salt-free aqueous suspensions of highly-charged colloidal particles for semi-dilute specimens of concentration 0.1-10.0 vol%. Kossel diffraction patterns which represent faithfully accurate information on lattice symmetries in the suspensions enable us to investigate the time evolution of colloidal crystals. The results show that the crystallization proceeds by way of the following intermediate phase transitions: two-dimensional hcp structure → random layer structure → layer structure with one sliding degree of freedom → stacking disorder structure → stacking structure with multivariant periodicity → fcc twin structure with twin plane (111) → normal fcc structure → bcc twin structure with twin plane (11-bar2) or (1-bar12) → normal bcc structure. For concentrated suspensions (>2 vol %), the phase transition ceases to proceed at the normal fcc structure. (author)

  14. Diffraction efficiency enhancement of femtosecond laser-engraved diffraction gratings due to CO{sub 2} laser polishing

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hun-Kook [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Chosun University, Gwangju (Korea, Republic of); Jung, Deok; Sohn, Ik-Bu; Noh, Young-Chul; Lee, Yong-Tak [Gwangju Institute of Science and Technology, Gwangju (Korea, Republic of); Kim, Jin-Tae [Chosun University, Gwangju (Korea, Republic of); Ahsan, Shamim [Khulna University, Khulna (Bangladesh)

    2014-11-15

    This research demonstrates laser-assisted fabrication of high-efficiency diffraction gratings in fused-silica glass samples. Initially, femtosecond laser pulses are used to engrave diffraction gratings on the glass surfaces. Then, these micro-patterned glass samples undergo CO{sub 2} laser polishing process. unpolished diffraction gratings encoded in the glass samples show an overall diffraction efficiency of 18.1%. diffraction gratings imprinted on the glass samples and then polished four times by using a CO{sub 2} laser beam attain a diffraction efficiency of 32.7%. We also investigate the diffraction patterns of the diffraction gratings encoded on fused-silica glass surfaces. The proposed CO{sub 2} laser polishing technique shows great potential in patterning high-efficiency diffraction gratings on the surfaces of various transparent materials.

  15. Measuring Spray Droplet Size from Agricultural Nozzles Using Laser Diffraction

    Science.gov (United States)

    Fritz, Bradley K.; Hoffmann, W. Clint

    2016-01-01

    When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to make an application so that the material reaches the target site (i.e., plant). Information critical in this process is the droplet size that a particular spray nozzle, spray pressure, and spray solution combination generates, as droplet size greatly influences product efficacy and how the spray moves through the environment. Researchers and product manufacturers commonly use laser diffraction equipment to measure the spray droplet size in laboratory wind tunnels. The work presented here describes methods used in making spray droplet size measurements with laser diffraction equipment for both ground and aerial application scenarios that can be used to ensure inter- and intra-laboratory precision while minimizing sampling bias associated with laser diffraction systems. Maintaining critical measurement distances and concurrent airflow throughout the testing process is key to this precision. Real time data quality analysis is also critical to preventing excess variation in the data or extraneous inclusion of erroneous data. Some limitations of this method include atypical spray nozzles, spray solutions or application conditions that result in spray streams that do not fully atomize within the measurement distances discussed. Successful adaption of this method can provide a highly efficient method for evaluation of the performance of agrochemical spray application nozzles under a variety of operational settings. Also discussed are potential experimental design considerations that can be included to enhance functionality of the data collected. PMID:27684589

  16. Computer controlling of writing beam in laser microfabrication of diffractive optics

    OpenAIRE

    Korolkov, V.; Shimansky, R.; Cherkashin, V.; Denk, D.

    2003-01-01

    Laser microfabrication of diffractive optics with continuous relief is based on the direct local action of focused laser radiation on the recording material. Control of writing beam parameters (beam power, spot size, waist position) is one of the main tasks in microfabrication using laser writing systems. Method of the control defines the correspondence between the fabricated microrelief of the diffractive optical element and a designed one. Complexity of this task consists in the necessity t...

  17. Diffractive beam shaping for enhanced laser polymer welding

    Science.gov (United States)

    Rauschenberger, J.; Vogler, D.; Raab, C.; Gubler, U.

    2015-03-01

    Laser welding of polymers increasingly finds application in a large number of industries such as medical technology, automotive, consumer electronics, textiles or packaging. More and more, it replaces other welding technologies for polymers, e. g. hot-plate, vibration or ultrasonic welding. At the same rate, demands on the quality of the weld, the flexibility of the production system and on processing speed have increased. Traditionally, diode lasers were employed for plastic welding with flat-top beam profiles. With the advent of fiber lasers with excellent beam quality, the possibility to modify and optimize the beam profile by beam-shaping elements has opened. Diffractive optical elements (DOE) can play a crucial role in optimizing the laser intensity profile towards the optimal M-shape beam for enhanced weld seam quality. We present results on significantly improved weld seam width constancy and enlarged process windows compared to Gaussian or flat-top beam profiles. Configurations in which the laser beam diameter and shape can be adapted and optimized without changing or aligning the laser, fiber-optic cable or optical head are shown.

  18. Remote Laser Diffraction Particle Size Distribution Analyzer

    Energy Technology Data Exchange (ETDEWEB)

    Batcheller, Thomas Aquinas; Huestis, Gary Michael; Bolton, Steven Michael

    2001-03-01

    In support of a radioactive slurry sampling and physical characterization task, an “off-the-shelf” laser diffraction (classical light scattering) particle size analyzer was utilized for remote particle size distribution (PSD) analysis. Spent nuclear fuel was previously reprocessed at the Idaho Nuclear Technology and Engineering Center (INTEC—formerly recognized as the Idaho Chemical Processing Plant) which is on DOE’s INEEL site. The acidic, radioactive aqueous raffinate streams from these processes were transferred to 300,000 gallon stainless steel storage vessels located in the INTEC Tank Farm area. Due to the transfer piping configuration in these vessels, complete removal of the liquid can not be achieved. Consequently, a “heel” slurry remains at the bottom of an “emptied” vessel. Particle size distribution characterization of the settled solids in this remaining heel slurry, as well as suspended solids in the tank liquid, is the goal of this remote PSD analyzer task. A Horiba Instruments Inc. Model LA-300 PSD analyzer, which has a 0.1 to 600 micron measurement range, was modified for remote application in a “hot cell” (gamma radiation) environment. This technology provides rapid and simple PSD analysis, especially down in the fine and microscopic particle size regime. Particle size analysis of these radioactive slurries down in this smaller range was not previously achievable—making this technology far superior than the traditional methods used. Successful acquisition of this data, in conjunction with other characterization analyses, provides important information that can be used in the myriad of potential radioactive waste management alternatives.

  19. Assessment of Multiple Scattering Errors of Laser Diffraction Instruments

    National Research Council Canada - National Science Library

    Strakey, Peter

    2003-01-01

    The accuracy of two commercial laser diffraction instruments was compared under conditions of multiple scattering designed to simulate the high droplet number densities encountered in liquid propellant rocket combustors...

  20. Phase knife-edge laser Schlieren diffraction interferometry with ...

    Indian Academy of Sciences (India)

    journal of. April 2007 physics pp. 581–589. Phase knife-edge laser Schlieren diffraction ... tion in the Schlieren image/interferogram for quantitative analysis. ..... entific & Industrial Research, New Delhi for financial support (Emeritus Scientist.

  1. Babinet principle and diffraction losses in laser resonators

    International Nuclear Information System (INIS)

    Kubarev, V V

    2000-01-01

    A simple analytical technique, based on the Babinet principle, for calculating low diffraction losses of different kinds in stable resonators is described. The technique was verified by comparison with the known numerical and analytical calculations of the losses in specific diffraction problems. (laser applications and other topics in quantum electronics)

  2. Ultrafast molecular imaging by laser-induced electron diffraction

    International Nuclear Information System (INIS)

    Peters, M.; Nguyen-Dang, T. T.; Cornaggia, C.; Saugout, S.; Charron, E.; Keller, A.; Atabek, O.

    2011-01-01

    We address the feasibility of imaging geometric and orbital structures of a polyatomic molecule on an attosecond time scale using the laser-induced electron diffraction (LIED) technique. We present numerical results for the highest molecular orbitals of the CO 2 molecule excited by a near-infrared few-cycle laser pulse. The molecular geometry (bond lengths) is determined within 3% of accuracy from a diffraction pattern which also reflects the nodal properties of the initial molecular orbital. Robustness of the structure determination is discussed with respect to vibrational and rotational motions with a complete interpretation of the laser-induced mechanisms.

  3. Soil Texture Aanalysis by Laser Diffraction – Standardisation Needed

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Palviainen, Marjo; Kjoenaas, O. Janne

    2017-01-01

    sedimentation and sieving methods have been well-defined. From literature and a mini-survey, we know already that laser diffraction is a commonly used analytical method for soil PSD determination in scientific environmental studies that involve soils. A body of literature has documented that colloid......-sized fraction results obtained by laser diffraction analysis of fine-textured soil samples are not comparable to those obtained with sedimentation and sieving methods, when translating to the traditional particle size limits clay, silt and sand. Also, operating procedures for pretreatment of soil samples...... content. We conclude that PSD’s obtained by the laser diffraction method are repeatable and mostly reproducible given standardised pretreatment. Translation to texture class using traditional separates does not work well, and more work and new PTF’s for soils are needed that can translate a laser...

  4. Diffractive optics for industrial and commercial applications

    Energy Technology Data Exchange (ETDEWEB)

    Turunen, J. [Joensuu Univ. (Finland); Wyrowski, F. [eds.] [Jena Univ. (Germany)

    1997-12-31

    The following topics were dealt with: diffractive optics, diffraction gratings, optical system design with diffractive optics, continuous-relief diffractive lenses and microlens arrays, diffractive bifocal intraocular lenses, diffractive laser resonators, diffractive optics for semiconductor lasers, diffractive elements for optical image processing, photorefractive crystals in optical measurement systems, subwavelenth-structured elements, security applications, diffractive optics for solar cells, holographic microlithography. 999 refs.

  5. Holographic diffraction gratings as laser radiation protection filters

    International Nuclear Information System (INIS)

    Pantelic, D.; Pantelic, G.

    2006-01-01

    Holographic volume diffraction gratings are used as attenuation filters, due to their selective spectral transmission. They can be tailored to reflect or transmit narrow spectral ranges by adjusting spatial frequency of Bragg grating in carefully chosen photosensitive materials, like silver-halide emulsion or di-chromated gelatin layers. If properly recorded and chemically processed, resulting gratings can significantly attenuate light at wavelengths corresponding to various laser spectral lines. Thus, they can be used as filters in laser protection goggles. We analyze the characteristics of Bragg gratings necessary to obtain high attenuation coefficients. Also, their angular selectivity is taken into account and corresponding experimental conditions are investigated. Although di-chromated gelatin seems to be almost ideal material, due to its almost 100% diffraction efficiency, environmental stability is poor (degradation under humid environment), thus making its practical usage difficult. Thus, we have analyzed alternative materials like di-chromated pullulan, which is stable under normal environmental conditions (without drop in diffraction efficiency after prolonged exposure to humidity). Pullulan is polymer (polysaccharide) of biologic origin produced by certain bacteria. If doped with chromium ions it becomes photosensitive, enabling recording of diffraction gratings with spatial frequency of more than 3000 lines/mm. Material is chemically processed by mixture of isopropyl alcohol and water. Both thick and thin layers can be produced by gravity settling. Spectral properties of resulting gratings are analyzed, showing that they can significantly attenuate laser light of particular wavelength, depending of grating period and its slant angle. (authors)

  6. Time-resolved measurements with streaked diffraction patterns from electrons generated in laser plasma wakefield

    Science.gov (United States)

    He, Zhaohan; Nees, John; Hou, Bixue; Krushelnick, Karl; Thomas, Alec; Beaurepaire, Benoît; Malka, Victor; Faure, Jérôme

    2013-10-01

    Femtosecond bunches of electrons with relativistic to ultra-relativistic energies can be robustly produced in laser plasma wakefield accelerators (LWFA). Scaling the electron energy down to sub-relativistic and MeV level using a millijoule laser system will make such electron source a promising candidate for ultrafast electron diffraction (UED) applications due to the intrinsic short bunch duration and perfect synchronization with the optical pump. Recent results of electron diffraction from a single crystal gold foil, using LWFA electrons driven by 8-mJ, 35-fs laser pulses at 500 Hz, will be presented. The accelerated electrons were collimated with a solenoid magnetic lens. By applying a small-angle tilt to the magnetic lens, the diffraction pattern can be streaked such that the temporal evolution is separated spatially on the detector screen after propagation. The observable time window and achievable temporal resolution are studied in pump-probe measurements of photo-induced heating on the gold foil.

  7. Fast parallel diffractive multi-beam femtosecond laser surface micro-structuring

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Kuang, E-mail: z.kuang@liv.ac.uk [Laser Group, Department of Engineering, University of Liverpool, Brodie Building, Liverpool L69 3GQ (United Kingdom); Dun Liu; Perrie, Walter; Edwardson, Stuart; Sharp, Martin; Fearon, Eamonn; Dearden, Geoff; Watkins, Ken [Laser Group, Department of Engineering, University of Liverpool, Brodie Building, Liverpool L69 3GQ (United Kingdom)

    2009-04-15

    Fast parallel femtosecond laser surface micro-structuring is demonstrated using a spatial light modulator (SLM). The Gratings and Lenses algorithm, which is simple and computationally fast, is used to calculate computer generated holograms (CGHs) producing diffractive multiple beams for the parallel processing. The results show that the finite laser bandwidth can significantly alter the intensity distribution of diffracted beams at higher angles resulting in elongated hole shapes. In addition, by synchronisation of applied CGHs and the scanning system, true 3D micro-structures are created on Ti6Al4V.

  8. Diffractive and coloured films by laser interferometry patterning

    Czech Academy of Sciences Publication Activity Database

    Peláez, R.J.; Afonso, C.N.; Bulíř, Jiří; Lančok, Ján; Novotný, Michal

    2012-01-01

    Roč. 211, Oct (2012), s. 205-208 ISSN 0257-8972 R&D Projects: GA AV ČR IAA100100718; GA ČR GP202/09/P324 Institutional research plan: CEZ:AV0Z10100522 Keywords : laser-patterning * metal * films * nanoparticles * diffraction * colour Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.941, year: 2012

  9. Investigation of diffractive optical element femtosecond laser machining

    Energy Technology Data Exchange (ETDEWEB)

    Chabrol, Grégoire R., E-mail: g.chabrol@ecam-strasbourg.eu [ECAM Strasbourg-Europe, Espace Européen de l’entreprise, 2, rue de Madrid – 67300 SCHILTIGHEIM, CS. 20013, 67012 Strasbourg CEDEX (France); Laboratoire des Sciences de l’Ingénieur, de l’Informatique et de l’Imagerie (ICube), UDS-CNRS, UMR 7357, 300 bld Sébastien Brant, CS 10413, 67412 Illkirch cedex (France); Ciceron, Adline [ECAM Strasbourg-Europe, Espace Européen de l’entreprise, 2, rue de Madrid – 67300 SCHILTIGHEIM, CS. 20013, 67012 Strasbourg CEDEX (France); Laboratoire des Sciences de l’Ingénieur, de l’Informatique et de l’Imagerie (ICube), UDS-CNRS, UMR 7357, 300 bld Sébastien Brant, CS 10413, 67412 Illkirch cedex (France); Twardowski, Patrice; Pfeiffer, Pierre [Laboratoire des Sciences de l’Ingénieur, de l’Informatique et de l’Imagerie (ICube), UDS-CNRS, UMR 7357, 300 bld Sébastien Brant, CS 10413, 67412 Illkirch cedex (France); Télécom Physique Strasbourg – Pôle API – 300 Bd Sébastien Brant – CS 10413, Illkirch Graffenstaden F 67400 (France); and others

    2016-06-30

    Highlights: • A method for rapid manufacturing of optical diffractive element in BK7 is proposed. • A binary grating in BK7 was successfully machined by femtosecond laser pulses. • Process relying on nonlinear absorption in the dielectric due to photoionization. • The binary grating was analysed by SEM and interferometric microscopy. • Simulations by Fourier modal method supported the measured diffractive efficiency. - Abstract: This paper presents an explorative study on the machining of diffractive optical elements (DOEs) in transparent materials using a femtosecond laser source. A simple form of DOE, a binary phase grating with a period of 20.85 μm (σ = 0.5 μm), a groove depth and width of 0.7 μm (σ = 0.2 μm) and 8.8 μm (σ = 0.5 μm) respectively, was successfully machined in BK7. The topographic characteristics were measured by white light interferometry and scanning electron microscopy (SEM). The processing was carried out on high precision stages with an ultrafast fibre laser (350 fs) emitting a 343 nm pulse focused onto the sample with a stationary microscope objective. A diffracted efficiency of 27%, obtained with a spectro goniometer, was corroborated by the theoretical results obtained by the Fourier modal method (FMM), taking into account the measured topographic values. These encouraging results demonstrate that high-speed femtosecond laser manufacturing of DOE in bulk glasses can be achieved, opening the way to rapid prototyping of multi-layered-DOEs.

  10. High power lasers & systems

    OpenAIRE

    Chatwin, Chris; Young, Rupert; Birch, Philip

    2015-01-01

    Some laser history;\\ud Airborne Laser Testbed & Chemical Oxygen Iodine Laser (COIL);\\ud Laser modes and beam propagation;\\ud Fibre lasers and applications;\\ud US Navy Laser system – NRL 33kW fibre laser;\\ud Lockheed Martin 30kW fibre laser;\\ud Conclusions

  11. Fabrication of synthetic diffractive elements using advanced matrix laser lithography

    International Nuclear Information System (INIS)

    Škeren, M; Svoboda, J; Kveton, M; Fiala, P

    2013-01-01

    In this paper we present a matrix laser writing device based on a demagnified projection of a micro-structure from a computer driven spatial light modulator. The device is capable of writing completely aperiodic micro-structures with resolution higher than 200 000 DPI. An optical system is combined with ultra high precision piezoelectric stages with an elementary step ∼ 4 nm. The device operates in a normal environment, which significantly decreases the costs compared to competitive technologies. Simultaneously, large areas can be exposed up to 100 cm2. The capabilities of the constructed device will be demonstrated on particular elements fabricated for real applications. The optical document security is the first interesting field, where the synthetic image holograms are often combined with sophisticated aperiodic micro-structures. The proposed technology can easily write simple micro-gratings creating the color and kinetic visual effects, but also the diffractive cryptograms, waveguide couplers, and other structures recently used in the field of optical security. A general beam shaping elements and special photonic micro-structures are another important applications which will be discussed in this paper.

  12. Fabrication of synthetic diffractive elements using advanced matrix laser lithography

    Science.gov (United States)

    Škereň, M.; Svoboda, J.; Květoň, M.; Fiala, P.

    2013-02-01

    In this paper we present a matrix laser writing device based on a demagnified projection of a micro-structure from a computer driven spatial light modulator. The device is capable of writing completely aperiodic micro-structures with resolution higher than 200 000 DPI. An optical system is combined with ultra high precision piezoelectric stages with an elementary step ~ 4 nm. The device operates in a normal environment, which significantly decreases the costs compared to competitive technologies. Simultaneously, large areas can be exposed up to 100 cm2. The capabilities of the constructed device will be demonstrated on particular elements fabricated for real applications. The optical document security is the first interesting field, where the synthetic image holograms are often combined with sophisticated aperiodic micro-structures. The proposed technology can easily write simple micro-gratings creating the color and kinetic visual effects, but also the diffractive cryptograms, waveguide couplers, and other structures recently used in the field of optical security. A general beam shaping elements and special photonic micro-structures are another important applications which will be discussed in this paper.

  13. Classical system underlying a diffracting quantum billiard

    Indian Academy of Sciences (India)

    Manan Jain

    2018-01-05

    Jan 5, 2018 ... Wave equation; rays; quantum chaos. PACS Nos 03.65.Ge; 05.45.Mt; 42.25.Fx. 1. Introduction. Diffraction [1] is a complex wave phenomenon which manifests classically and quantum mechanically. Among a wide range of systems where diffraction becomes important, there is an interesting situation of.

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

    Science.gov (United States)

    Ramos-Izquierdo, Luis A.

    2011-01-01

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

  15. Definition and measurement of the times-diffraction-limit number of high-power laser beams

    Science.gov (United States)

    Bollanti, Sarah; Di Lazzaro, Paolo; Murra, Daniele

    1998-07-01

    A novel definition of the times-diffraction-limit (TDL) number of a laser beam is given. A comparison is made with the commonly used beam-propagation parameter M2, which is unreliable for hard-edge beams, like those produced by unstable resonators with diffraction output coupling. The new suggested TDL number definition doesn't rely on the real beam comparison to a Gaussian beam, but on the comparison of the far-field performances of the real beam with respect to those of a uniphase beam with the same amplitude profile in the near field. A practical method is also given for the estimation of the TDL number of real beams. Finally, this procedure is applied to the high-peak-power laser beams generated by two excimer laser systems developed in ENEA.

  16. Diffractive optical elements for transformation of modes in lasers

    Science.gov (United States)

    Sridharan, Arun K.; Pax, Paul H.; Heebner, John E.; Drachenberg, Derrek R.; Armstrong, James P.; Dawson, Jay W.

    2015-09-01

    Spatial mode conversion modules are described, with the capability of efficiently transforming a given optical beam profile, at one plane in space into another well-defined optical beam profile at a different plane in space, whose detailed spatial features and symmetry properties can, in general, differ significantly. The modules are comprised of passive, high-efficiency, low-loss diffractive optical elements, combined with Fourier transform optics. Design rules are described that employ phase retrieval techniques and associated algorithms to determine the necessary profiles of the diffractive optical components. System augmentations are described that utilize real-time adaptive optical techniques for enhanced performance as well as power scaling.

  17. Diffractive elements for generating microscale laser beam patterns: a Y2K problem

    Science.gov (United States)

    Teiwes, Stephan; Krueger, Sven; Wernicke, Guenther K.; Ferstl, Margit

    2000-03-01

    Lasers are widely used in industrial fabrication for engraving, cutting and many other purposes. However, material processing at very small scales is still a matter of concern. Advances in diffractive optics could provide for laser systems that could be used for engraving or cutting of micro-scale patterns at high speeds. In our paper we focus on the design of diffractive elements which can be used for this special application. It is a common desire in material processing to apply 'discrete' as well as 'continuous' beam patterns. Especially, the latter case is difficult to handle as typical micro-scale patterns are characterized by bad band-limitation properties, and as speckles can easily occur in beam patterns. It is shown in this paper that a standard iterative design method usually fails to obtain diffractive elements that generate diffraction patterns with acceptable quality. Insights gained from an analysis of the design problems are used to optimize the iterative design method. We demonstrate applicability and success of our approach by the design of diffractive phase elements that generate a discrete and a continuous 'Y2K' pattern.

  18. Soil texture analysis by laser diffraction - standardization needed

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Palviainen, M.; Kjønaas, O. Janne

    2017-01-01

    Soil texture is a central soil quality property. Laser diffraction (LD) for determination of particle size distribution (PSD) is now widespread due to easy analysis and low cost. However, pretreatment methods and interpretation of the resulting soil PSD’s are not standardized. Comparison of LD data...... with sedimentation and sieving data may cause misinterpretation and confusion. In literature that reports PSD’s based on LD, pretreatment methods, operating procedures and data methods are often underreported or not reported, although literature stressing the importance exists (e.g. Konert and Vandenberghe, 1997...... and many newer; ISO 13320:2009). PSD uncertainty caused by pretreatments and PSD bias caused by plate-shaped clay particles still calls for more method standardization work. If LD is used more generally, new pedotransfer functions for other soil properties (e.g water retention) based on sieving...

  19. Comparison of laser diffraction and image analysis for measurement of Streptomyces coelicolor cell clumps and pellets

    DEFF Research Database (Denmark)

    Rønnest, Nanna Petersen; Stocks, Stuart M; Eliasson Lantz, Anna

    2012-01-01

    and pellets of Streptomyces coelicolor compare to image analysis. Samples, taken five times during fed-batch cultivation, were analyzed by image analysis and laser diffraction. The volume-weighted size distribution was calculated for each sample. Laser diffraction and image analysis yielded similar size...

  20. COMPARING PARTICLE SIZE DISTRIBUTION ANALYSIS BY SEDIMENTATION AND LASER DIFFRACTION METHOD

    OpenAIRE

    Vito Ferro; Stefano Mirabile

    2009-01-01

    In this paper a brief review of the laser diffraction method is firstly carried out. Then, for 30 soil samples having a different texture classification sampled in Sicilian basin, a comparison between the two techniques is developed. The analysis demonstrated that the sand content measured by Sieve-Hydrometer method can be assumed equal to the one determinated by laser diffraction technique while an overestimation of the clay fraction measured by Sieve-Hydrometer method respect to laser diffr...

  1. Diffraction-limited 577 nm true-yellow laser by frequency doubling of a tapered diode laser

    Science.gov (United States)

    Christensen, Mathias; Vilera, Mariafernanda; Noordegraaf, Danny; Hansen, Anders K.; Buß, Thomas; Jensen, Ole B.; Skovgaard, Peter M. W.

    2018-02-01

    A wide range of laser medical treatments are based on coagulation of blood by absorption of the laser radiation. It has, therefore, always been a goal of these treatments to maximize the ratio of absorption in the blood to that in the surrounding tissue. For this purpose lasers at 577 nm are ideal since this wavelength is at the peak of the absorption in oxygenated hemoglobin. Furthermore, 577 nm has a lower absorption in melanin when compared to green wavelengths (515 - 532 nm), giving it an advantage when treating at greater penetration depth. Here we present a laser system based on frequency doubling of an 1154 nm Distributed Bragg Reflector (DBR) tapered diode laser, emitting 1.1 W of single frequency and diffraction limited yellow light at 577 nm, corresponding to a conversion efficiency of 30.5%. The frequency doubling is performed in a single pass configuration using a cascade of two bulk non-linear crystals. The system is power stabilized over 10 hours with a standard deviation of 0.13% and the relative intensity noise is measured to be 0.064 % rms.

  2. Compact diffraction grating laser wavemeter for cold atom experiments

    Science.gov (United States)

    Wei, Chun-hua; Yan, Shu-hua; Zhang, Tian

    2017-09-01

    We present an innovative and practical scheme of building a miniaturized wavemeter, with the advantages of low cost, high reliability and simple structure. Through a calibration test by a 780 nm external cavity diode laser (ECDL), the results show that our system gets a wavelength resolution of better than 1 pm, measurement accuracy of better than 2 pm (corresponding to a frequency of 1 GHz), and a measurement range of 8.5 nm. Finally, the multi-mode comparison test between our system and a commercial spectrum analyzer further indicates the high-precision, miniaturization and low cost of the proposed system, which shows that it is particularly suitable for ECDL and atom cooling and trapping experiments. The system design, experimental results and conclusions are of definite significance as a fine reference for other ranges of wavelength.

  3. Multiple Order Diffractions by laser-Injured Transient Grating in Nematic MBBA Film

    International Nuclear Information System (INIS)

    Kim, Seong Kyu; Kim, Hack Jin

    1999-01-01

    The laser-induced transient grating method is applied to study the dynamics of the nematic MBBA film. The nanosecond laser pulses of 355 nm are used to make the transient grating and the cw He-Ne laser of 633 nm is used to probe the dynamics. Strong multiple order diffractions are observed at high nematic temperatures. The reordering process induced by the phototransformed state, which is the locally melted state from the nematic sample, is attributed to the main origin of the multiple order diffractions from the nematic MBBA. The characteristics of the multiple order gratings are discussed with the grating profiles simulated from the multiple diffraction signals

  4. COMPARING PARTICLE SIZE DISTRIBUTION ANALYSIS BY SEDIMENTATION AND LASER DIFFRACTION METHOD

    Directory of Open Access Journals (Sweden)

    Vito Ferro

    2009-06-01

    Full Text Available In this paper a brief review of the laser diffraction method is firstly carried out. Then, for 30 soil samples having a different texture classification sampled in Sicilian basin, a comparison between the two techniques is developed. The analysis demonstrated that the sand content measured by Sieve-Hydrometer method can be assumed equal to the one determinated by laser diffraction technique while an overestimation of the clay fraction measured by Sieve-Hydrometer method respect to laser diffraction technique was obtained. Finally a set of equations useful to refer LD measurements to SH method was proposed.

  5. Laser cutting system

    Science.gov (United States)

    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.

  6. Multi-wavelength speckle reduction for laser pico-projectors using diffractive optics

    Science.gov (United States)

    Thomas, Weston H.

    Personal electronic devices, such as cell phones and tablets, continue to decrease in size while the number of features and add-ons keep increasing. One particular feature of great interest is an integrated projector system. Laser pico-projectors have been considered, but the technology has not been developed enough to warrant integration. With new advancements in diode technology and MEMS devices, laser-based projection is currently being advanced for pico-projectors. A primary problem encountered when using a pico-projector is coherent interference known as speckle. Laser speckle can lead to eye irritation and headaches after prolonged viewing. Diffractive optical elements known as diffusers have been examined as a means to lower speckle contrast. Diffusers are often rotated to achieve temporal averaging of the spatial phase pattern provided by diffuser surface. While diffusers are unable to completely eliminate speckle, they can be utilized to decrease the resultant contrast to provide a more visually acceptable image. This dissertation measures the reduction in speckle contrast achievable through the use of diffractive diffusers. A theoretical Fourier optics model is used to provide the diffuser's stationary and in-motion performance in terms of the resultant contrast level. Contrast measurements of two diffractive diffusers are calculated theoretically and compared with experimental results. In addition, a novel binary diffuser design based on Hadamard matrices will be presented. Using two static in-line Hadamard diffusers eliminates the need for rotation or vibration of the diffuser for temporal averaging. Two Hadamard diffusers were fabricated and contrast values were subsequently measured, showing good agreement with theory and simulated values. Monochromatic speckle contrast values of 0.40 were achieved using the Hadamard diffusers. Finally, color laser projection devices require the use of red, green, and blue laser sources; therefore, using a

  7. Comparison of infrared laser beam shaping by diffractive and refractive methods

    CSIR Research Space (South Africa)

    Forbes, A

    2005-08-01

    Full Text Available Infra-red laser beam shaping has the inherent difficulty that simple ray tracing methods often yield anomalous results, due primarily to the propagation effects at longer wavelengths. Techniques based on diffraction theory have been developed...

  8. Infrared laser system

    International Nuclear Information System (INIS)

    Cantrell, C.D.; Carbone, R.J.

    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

  9. Efficient generation of 3.9 W of diffraction-limited green light with spectrally combined tapered diode lasers

    DEFF Research Database (Denmark)

    Müller, André; Jensen, Ole Bjarlin; Andersen, Peter E.

    We propose an efficient concept increasing the power of diode laser systems in the visible spectral range. In comparison with second harmonic generation of single emitters, spectral beam combining with subsequent sum-frequency generation enhances the available power significantly. Combining two...... 1060 nm tapered diode lasers, we achieve a 2.5-3.2 fold increase of green light with a maximum power of 3.9 Watts in a diffraction-limited beam. At this level, diode lasers have a high application potential, for example, within the biomedical field. In order to enhance the power even further, our...

  10. Robot-laser system

    International Nuclear Information System (INIS)

    Akeel, H.A.

    1987-01-01

    A robot-laser system is described for providing a laser beam at a desired location, the system comprising: a laser beam source; a robot including a plurality of movable parts including a hollow robot arm having a central axis along which the laser source directs the laser beam; at least one mirror for reflecting the laser beam from the source to the desired location, the mirror being mounted within the robot arm to move therewith and relative thereto to about a transverse axis that extends angularly to the central axis of the robot arm; and an automatic programmable control system for automatically moving the mirror about the transverse axis relative to and in synchronization with movement of the robot arm to thereby direct the laser beam to the desired location as the arm is moved

  11. Characterization of diffraction gratings by use of a tabletop soft-x-ray laser

    International Nuclear Information System (INIS)

    Seminario, Max; Rocca, Jorge J.; Depine, Ricardo A.; Bach, Benny; Bach, Bernie

    2001-01-01

    We have demonstrated the use of a high-repetition-rate 46.9-mm tabletop laser to characterize diffraction gratings designed for grazing-incidence operation in the soft-x-ray spectral region. The efficiencies for various diffraction orders were measured as a function of angle of incidence and compared with the results of model simulations. This measurement technique provides benchmarks with which to improve electromagnetic codes used in the design of soft-x-ray diffraction gratings. The results illustrate the potential of compact tabletop soft-x-ray lasers for use as a new tool for characterization of short-wavelength optics at the manufacturer's site

  12. High-order diffraction gratings for high-power semiconductor lasers

    International Nuclear Information System (INIS)

    Vasil’eva, V. V.; Vinokurov, D. A.; Zolotarev, V. V.; Leshko, A. Yu.; Petrunov, A. N.; Pikhtin, N. A.; Rastegaeva, M. G.; Sokolova, Z. N.; Shashkin, I. S.; Tarasov, I. S.

    2012-01-01

    A deep diffraction grating with a large period (∼2 μm) within one of the cladding layers is proposed for the implementation of selective feedback in a semiconductor laser. Frequency dependences of reflectance in the 12th diffraction order for rectangular, triangular, and trapezoidal diffraction gratings are calculated. It is shown that the maximum reflectance of the waveguide mode is attained using a rectangular or trapezoidal grating ∼2 μm deep in the laser structure. Deep trapezoidal diffraction gratings with large periods are fabricated in the Al 0.3 Ga 0.7 As cladding layer of a GaAs/AlGaAs laser structure using photolithography and reactive ion etching.

  13. Dynamic correction of the laser beam coordinate in fabrication of large-sized diffractive elements for testing aspherical mirrors

    Science.gov (United States)

    Shimansky, R. V.; Poleshchuk, A. G.; Korolkov, V. P.; Cherkashin, V. V.

    2017-05-01

    This paper presents a method of improving the accuracy of a circular laser system in fabrication of large-diameter diffractive optical elements by means of a polar coordinate system and the results of their use. An algorithm for correcting positioning errors of a circular laser writing system developed at the Institute of Automation and Electrometry, SB RAS, is proposed and tested. Highprecision synthesized holograms fabricated by this method and the results of using these elements for testing the 6.5 m diameter aspheric mirror of the James Webb space telescope (JWST) are described..

  14. Laser transmitter system

    International Nuclear Information System (INIS)

    Dye, R.A.

    1975-01-01

    A laser transmitter system is disclosed which utilizes mechanical energy for generating an output pulse. The laser system includes a current developing device such as a piezoelectric crystal which charges a storage device such as a capacitor in response to a mechanical input signal. The capacitor is coupled to a switching device, such as a silicon controlled rectifier (SCR). The switching device is coupled to a laser transmitter such as a GaAs laser diode, which provides an output signal in response to the capacitor being discharged

  15. Effect of diffraction on stimulated Brillouin scattering from a single laser hot spot

    International Nuclear Information System (INIS)

    Eliseev, V.V.; Rozmus, W.; Tikhonchuk, V.T.; Capjack, C.E.

    1996-01-01

    A single laser hot spot in an underdense plasma is represented as a focused Gaussian laser beam. Stimulated Brillouin scattering (SBS) from such a Gaussian beam with small f/numbers 2-4 has been studied in a three-dimensional slab geometry. It is shown that the SBS reflectivity from a single laser hot spot is much lower than that predicted by a simple three wave coupling model because of the diffraction of the scattered light from the spatially localized ion acoustic wave. SBS gain per one Rayleigh length of the incident laser beam is proposed as a quantitative measure of this effect. Diffraction-limited SBS from a randomized laser beam is also discussed. copyright 1996 American Institute of Physics

  16. Shiva laser system performance

    International Nuclear Information System (INIS)

    Glaze, J.; Godwin, R.O.; Holzrichter, J.F.

    1978-01-01

    On November 18, 1977, after four years of experimentation, innovation, and construction, the Shiva High Energy Laser facility produced 10.2 kJ of focusable laser energy delivered in a 0.95 ns pulse. The Shiva laser, with its computer control system and delta amplifiers, demonstrated its versatility on May 18, 1978, when the first 20-beam target shot with delta amplifiers focused 26 TW on a target and produced a yield of 7.5 x 10 9 neutrons

  17. Coherent Rabi oscillations in a molecular system and sub-diffraction-limited pattern generation

    International Nuclear Information System (INIS)

    Liao, Zeyang; Al-Amri, M; Zubairy, M Suhail

    2015-01-01

    The resolution of a photolithography and optical imaging system is restricted by the diffraction limit. Coherent Rabi oscillations have been shown to be able to overcome the diffraction limit in a simple two-level atomic system (Z Liao, M Al-amri, and M S Zubairy 2010 Phys. Rev. Lett. 105 183601). In this paper, we numerically calculate the wave packet dynamics of a molecular system interacting with an ultrashort laser pulse and show that coherent Rabi oscillations in a molecular system are also possible. Moreover, a sub-diffraction-limited pattern can be generated in this system by introducing spatially modulated Rabi oscillations. We also discuss several techniques to improve the visibility of the sub-diffraction-limited pattern. Our result may have important applications in super-resolution optical lithography and optical imaging. (paper)

  18. Powering laser diode systems

    CERN Document Server

    Trestman, Grigoriy A

    2017-01-01

    This Tutorial Text discusses the competent design and skilled use of laser diode drivers (LDDs) and power supplies (PSs) for the electrical components of laser diode systems. It is intended to help power-electronic design engineers during the initial design stages: the choice of the best PS topology, the calculation of parameters and components of the PS circuit, and the computer simulation of the circuit. Readers who use laser diode systems for research, production, and other purposes will also benefit. The book will help readers avoid errors when creating laser systems from ready-made blocks, as well as understand the nature of the "mystical failures" of laser diodes (and possibly prevent them).

  19. Diffraction, self-focusing, and the geometrical optics limit in laser produced plasmas

    International Nuclear Information System (INIS)

    Marchand, R.; Rankin, R.; Capjack, C.E.; Birnboim, A.

    1987-01-01

    The effect of diffraction on the self-modulation of an intense laser beam in an initially uniform hydrogen plasma is investigated. A formalism is used in which the diffraction term in the paraxial wave equation can be arbitrarily reduced by the use of a weight factor iota. In the limit where iota approaches zero, it is shown that the paraxial wave equation correctly reduces to the geometrical optics limit and that the problem then becomes formally equivalent to solving the ray-tracing equations. When iota = 1, the paraxial wave equation takes its usual form and diffraction is fully accounted for. This formalism is applied to the simulation of self-modulation of an intense laser beam in a hydrogen plasma, for which diffraction is shown to be significant

  20. Frequency Tuning of IR First-Overtone CO Laser Radiation by Diffraction Grating and Frequency Selective Output Couplers

    National Research Council Canada - National Science Library

    Ionin, Andre

    1999-01-01

    ...: The contractor will investigate, both experimentally and theoretically, the feasibility of frequency tuning the first overtone carbon monoxide laser radiation by the use of diffraction gratings...

  1. Laser Megajoule synchronization system

    International Nuclear Information System (INIS)

    Luttmann, M.; Pastor, J.F; Drouet, V.; Prat, M.; Raimbourg, J.; Adolf, A.

    2011-01-01

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

  2. LAPU2: a laser pulse propagation code with diffraction

    International Nuclear Information System (INIS)

    Goldstein, J.C.; Dickman, D.O.

    1978-03-01

    Complete descriptions of the mathematical models and numerical methods used in the code LAPU2 are presented. This code can be used to study the propagation with diffraction of a temporally finite pulse through a sequence of resonant media and simple optical components. The treatment assumes cylindrical symmetry and allows nonlinear refractive indices. An unlimited number of different media can be distributed along the propagation path of the pulse. A complete users guide to input data is given as well as a FORTRAN listing of the code

  3. In situ laser heating and radial synchrotron X-ray diffraction ina diamond anvil cell

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, Martin; Caldwell, Wendel A.; Miyagi, Lowell; Wenk,Hans-Rudolf

    2007-06-29

    We report a first combination of diamond anvil cell radialx-ray diffraction with in situ laser heating. The laser-heating setup ofALS beamline 12.2.2 was modified to allow one-sided heating of a samplein a diamond anvil cell with an 80 W yttrium lithium fluoride laser whileprobing the sample with radial x-ray diffraction. The diamond anvil cellis placed with its compressional axis vertical, and perpendicular to thebeam. The laser beam is focused onto the sample from the top while thesample is probed with hard x-rays through an x-ray transparentboron-epoxy gasket. The temperature response of preferred orientation of(Fe,Mg)O is probed as a test experiment. Recrystallization was observedabove 1500 K, accompanied by a decrease in stress.

  4. Reconstruction of Laser-Induced Surface Topography from Electron Backscatter Diffraction Patterns.

    Science.gov (United States)

    Callahan, Patrick G; Echlin, McLean P; Pollock, Tresa M; De Graef, Marc

    2017-08-01

    We demonstrate that the surface topography of a sample can be reconstructed from electron backscatter diffraction (EBSD) patterns collected with a commercial EBSD system. This technique combines the location of the maximum background intensity with a correction from Monte Carlo simulations to determine the local surface normals at each point in an EBSD scan. A surface height map is then reconstructed from the local surface normals. In this study, a Ni sample was machined with a femtosecond laser, which causes the formation of a laser-induced periodic surface structure (LIPSS). The topography of the LIPSS was analyzed using atomic force microscopy (AFM) and reconstructions from EBSD patterns collected at 5 and 20 kV. The LIPSS consisted of a combination of low frequency waviness due to curtaining and high frequency ridges. The morphology of the reconstructed low frequency waviness and high frequency ridges matched the AFM data. The reconstruction technique does not require any modification to existing EBSD systems and so can be particularly useful for measuring topography and its evolution during in situ experiments.

  5. Design and application of a new modular adapter for laser diffraction characterization of inhalation aerosols

    NARCIS (Netherlands)

    de Boer, Anne; Gjaltema, D; Hagedoorn, P; Schaller, M; Witt, W; Frijlink, H W

    2002-01-01

    An inhaler adapter has been designed for the characterization of the aerosol clouds from medical aerosol generators such as nebulizers, dry powder inhalers (dpis) and metered dose inhalers (mdis) with laser diffraction technology. The adapter has a pre-separator, for separation of large particles

  6. Toward atomic resolution diffractive imaging of isolated molecules with x-ray free-electron lasers

    DEFF Research Database (Denmark)

    Stern, Stephan; Holmegaard, Lotte; Filsinger, Frank

    2014-01-01

    We give a detailed account of the theoretical analysis and the experimental results of an x-ray-diffraction experiment on quantum-state selected and strongly laser-aligned gas-phase ensembles of the prototypical large asymmetric rotor molecule 2,5-diiodobenzonitrile, performed at the Linac Cohere...

  7. Electrically and spatially controllable PDLC phase gratings for diffraction and modulation of laser beams

    Energy Technology Data Exchange (ETDEWEB)

    Hadjichristov, Georgi B., E-mail: georgibh@issp.bas.bg [Laboratory of Optics and Spectroscopy, Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., BG-1784 Sofia (Bulgaria); Marinov, Yordan G.; Petrov, Alexander G. [Laboratory of Biomolecular Layers, Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee Blvd., BG-1784 Sofia, Bulgaria (Bulgaria)

    2016-03-25

    We present a study on electrically- and spatially-controllable laser beam diffraction, electrooptic (EO) phase modulation, as well as amplitude-frequency EO modulation by single-layer microscale polymer-dispersed liquid crystal (PDLC) phase gratings (PDLC SLPGs) of interest for device applications. PDLC SLPGs were produced from nematic liquid crystal (LC) E7 in photo-curable NOA65 polymer. The wedge-formed PDLC SLPGs have a continuously variable thickness (2–25 µm). They contain LC droplets of diameters twice as the layer thickness, with a linear-gradient size distribution along the wedge. By applying alternating-current (AC) electric field, the PDLC SLPGs produce efficient: (i) diffraction splitting of transmitted laser beams; (ii) spatial redistribution of diffracted light intensity; (iii) optical phase modulation; (iv) amplitude-frequency modulation, all controllable by the driven AC field and the droplet size gradient.

  8. Grain size analysis of sediments from the northern Andaman Sea: Comparison of laser diffraction and sieve-pipette techniques

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaswamy, V.; Rao, P.S.

    measured with laser diffraction show that 99% of the particles have an upper size range between 4.8 and 7.7 mu m. A calibration relationship between pipette and laser diffraction techniques has been developed for the northern Andaman Sea. A clay particle...

  9. Electron backscatter diffraction characterization of laser-induced periodic surface structures on nickel surface

    Energy Technology Data Exchange (ETDEWEB)

    Sedao, Xxx, E-mail: sedao.xxx@gmail.com [Laboratoire Hubert Curien, Université Jean Monnet, 42000 St-Etienne (France); Maurice, Claire [Laboratoire Georges Friedel, Ecole Nationale Supérieure des Mines, 42023 St-Etienne (France); Garrelie, Florence; Colombier, Jean-Philippe; Reynaud, Stéphanie [Laboratoire Hubert Curien, Université Jean Monnet, 42000 St-Etienne (France); Quey, Romain; Blanc, Gilles [Laboratoire Georges Friedel, Ecole Nationale Supérieure des Mines, 42023 St-Etienne (France); Pigeon, Florent [Laboratoire Hubert Curien, Université Jean Monnet, 42000 St-Etienne (France)

    2014-05-01

    Graphical abstract: -- Highlight: •Lattice rotation and its distribution in laser-induced periodic surface structures (LIPSS) and the subsurface region on a nickel substrate are revealed using electron backscatter diffraction (EBSD). -- Abstract: We report on the structural investigation of laser-induced periodic surface structures (LIPSS) generated in polycrystalline nickel target after multi-shot irradiation by femtosecond laser pulses. Electron backscatter diffraction (EBSD) is used to reveal lattice rotation caused by dislocation storage during LIPSS formation. Localized crystallographic damages in the LIPSS are detected from both surface and cross-sectional EBSD studies. A surface region (up to 200 nm) with 1–3° grain disorientation is observed in localized areas from the cross-section of the LIPSS. The distribution of the local disorientation is inhomogeneous across the LIPSS and the subsurface region.

  10. On the neutron diffraction in a crystal in the field of a standing laser wave

    International Nuclear Information System (INIS)

    Grigoryan, K.K.; Hayrapetyan, A.G.; Petrosyan, R.G.

    2010-01-01

    The possibility of high-energy neutron diffraction in a crystal is shown by applying the solution of time-dependent Schroedinger equation for a neutron in the field of a standing laser wave. The scattering picture is examined within the framework of non-stationary S-matrix theory, where the neutron-laser field interaction is considered exactly and the neutron-crystal interaction is considered as a perturbation described by Fermi pseudopotential (Farri representation). The neutron-crystal interaction is elastic, and the neutron-laser field interaction has both inelastic and elastic behaviors which results in the observation of an analogous to the Kapitza-Dirac effect for neutrons. The neutron scattering probability is calculated and the analysis of the results are adduced. Both inelastic and elastic diffraction conditions are obtained and the formation of a 'sublattice' is illustrated in the process of neutron-photon-phonon elastic interaction.

  11. Molecular Switch for Sub-Diffraction Laser Lithography by Photoenol Intermediate-State Cis-Trans Isomerization.

    Science.gov (United States)

    Mueller, Patrick; Zieger, Markus M; Richter, Benjamin; Quick, Alexander S; Fischer, Joachim; Mueller, Jonathan B; Zhou, Lu; Nienhaus, Gerd Ulrich; Bastmeyer, Martin; Barner-Kowollik, Christopher; Wegener, Martin

    2017-06-27

    Recent developments in stimulated-emission depletion (STED) microscopy have led to a step change in the achievable resolution and allowed breaking the diffraction limit by large factors. The core principle is based on a reversible molecular switch, allowing for light-triggered activation and deactivation in combination with a laser focus that incorporates a point or line of zero intensity. In the past years, the concept has been transferred from microscopy to maskless laser lithography, namely direct laser writing (DLW), in order to overcome the diffraction limit for optical lithography. Herein, we propose and experimentally introduce a system that realizes such a molecular switch for lithography. Specifically, the population of intermediate-state photoenol isomers of α-methyl benzaldehydes generated by two-photon absorption at 700 nm fundamental wavelength can be reversibly depleted by simultaneous irradiation at 440 nm, suppressing the subsequent Diels-Alder cycloaddition reaction which constitutes the chemical core of the writing process. We demonstrate the potential of the proposed mechanism for STED-inspired DLW by covalently functionalizing the surface of glass substrates via the photoenol-driven STED-inspired process exploiting reversible photoenol activation with a polymerization initiator. Subsequently, macromolecules are grown from the functionalized areas and the spatially coded glass slides are characterized by atomic-force microscopy. Our approach allows lines with a full-width-at-half-maximum of down to 60 nm and line gratings with a lateral resolution of 100 nm to be written, both surpassing the diffraction limit.

  12. Laser surveillance system (LASSY)

    International Nuclear Information System (INIS)

    Boeck, H.; Hammer, J.

    1988-01-01

    The development progress during the reporting period 1988 of the laser surveillance system of spent fuel pools is summarized. The present engineered system comes close to a final version for field application as all technical questions have been solved in 1988. 14 figs., 1 tab. (Author)

  13. Adaptability of laser diffraction measurement technique in soil physics methodology

    Science.gov (United States)

    Barna, Gyöngyi; Szabó, József; Rajkai, Kálmán; Bakacsi, Zsófia; Koós, Sándor; László, Péter; Hauk, Gabriella; Makó, András

    2016-04-01

    There are intentions all around the world to harmonize soils' particle size distribution (PSD) data by the laser diffractometer measurements (LDM) to that of the sedimentation techniques (pipette or hydrometer methods). Unfortunately, up to the applied methodology (e. g. type of pre-treatments, kind of dispersant etc.), PSDs of the sedimentation methods (due to different standards) are dissimilar and could be hardly harmonized with each other, as well. A need was arisen therefore to build up a database, containing PSD values measured by the pipette method according to the Hungarian standard (MSZ-08. 0205: 1978) and the LDM according to a widespread and widely used procedure. In our current publication the first results of statistical analysis of the new and growing PSD database are presented: 204 soil samples measured with pipette method and LDM (Malvern Mastersizer 2000, HydroG dispersion unit) were compared. Applying usual size limits at the LDM, clay fraction was highly under- and silt fraction was overestimated compared to the pipette method. Subsequently soil texture classes determined from the LDM measurements significantly differ from results of the pipette method. According to previous surveys and relating to each other the two dataset to optimizing, the clay/silt boundary at LDM was changed. Comparing the results of PSDs by pipette method to that of the LDM, in case of clay and silt fractions the modified size limits gave higher similarities. Extension of upper size limit of clay fraction from 0.002 to 0.0066 mm, and so change the lower size limit of silt fractions causes more easy comparability of pipette method and LDM. Higher correlations were found between clay content and water vapor adsorption, specific surface area in case of modified limit, as well. Texture classes were also found less dissimilar. The difference between the results of the two kind of PSD measurement methods could be further reduced knowing other routinely analyzed soil parameters

  14. CL 19: Anisotropy of the electron diffraction from femtosecond Laser excited Bismuth

    International Nuclear Information System (INIS)

    Zhou, P.; Ligges, M.; Streubuehr, C.; Brazda, Th.; Payer, Th.; Meyer zu Heringdorf, F.; Horn-von Hoegen, M.; Von der Linde, D.

    2010-01-01

    We report an electron diffraction experiment in Bi in which a linearly polarized E g optical phonon mode is detected after excitation of the material by a femtosecond laser pulse. Bismuth is a semimetal with rhombohedral crystal structure with two atoms in the unit cell. There are two types of optical phonon modes: (i) The totally symmetric A 1g mode which corresponds to a displacement of the atoms along the trigonal (111) direction, and (ii) the doubly degenerate E g mode which represents a motion in the plane perpendicular to (111). The A 1g mode can be coherently excited both by displacive excitation (DE) and by impulsive stimulated Raman scattering (ISRS). Symmetry properties prevent DE of E g modes leaving ISRS as a likely excitation mechanism. We performed time resolved electron diffraction experiments on femtosecond laser excited Bi membranes of 15 nm thickness which were grown on a NaCl crystal and detached by floating in water. The experimental setup is described elsewhere. The fundamental laser beam (800 nm) was used for the excitation of the Bi films. The films had a crystalline structure with the (111) axis perpendicular to the surface. The electron beam passed perpendicular to the surface through the film. In this geometry the diffraction pattern is insensitive to atomic displacements along the (111) direction, i.e. insensitive to A 1g phonon modes. On the other hand, the excitation of E g modes corresponding to atomic displacements in the plane normal to (111) decreases the intensity of particular diffraction orders. The individual cycles of the E g vibrations (duration 475 fs) could not be resolved because our time resolution about 700 fs was not sufficient. In our experiment excitation beam with a fluence of 1 mJ/cm 2 and variable linear polarization was incident from the backside at an angle of 40 degrees (counter propagating electron and laser beam). The diffraction patterns were recorded as a function of the delay time between laser pump and

  15. Reflection and diffraction of atomic de Broglie waves by evanescent laser waves. Bare-state method

    International Nuclear Information System (INIS)

    Feng, Xiaoping; Witte, N.S.; Hollenberg, C.L.; Opat, G.

    1994-01-01

    Two methods are presented for the investigation of the reflection and diffraction of atoms by gratings formed either by standing or travelling evanescent laser waves. Both methods use the bare-state rather than dressed-state picture. One method is based on the Born series, whereas the other is based on the Laplace transformation of the coupled differential equations. The two methods yield the same theoretical expressions for the reflected and diffracted atomic waves in the whole space including the interaction and the asymptotic regions. 1 ref., 1 fig

  16. Controlled molecules for X-ray diffraction experiments at free-electron lasers

    International Nuclear Information System (INIS)

    Stern, Stephan

    2013-12-01

    X-ray diffractive imaging is at the very heart of materials science and has been utilized for decades to solve unknown molecular structures. Nowadays, it serves as the key method of structural biology to solve molecular structures of large biological molecules comprising several thousand or even millions of atoms. However, X-ray diffraction from isolated molecules is very weak. Therefore, the regular and periodic arrangement of a huge number of identical copies of a certain molecule of interest within a crystal lattice has been a necessary condition in order to exploit Bragg diffraction of X-rays. This results in a huge increase in scattered signal and a strongly improved signal-to-noise ratio compared to diffraction from non-crystalline samples. The major bottleneck of structural biology is that many of biologically interesting molecules refuse to form crystals of sufficient size to be used at synchrotron X-ray lightsources. However, novel X-ray free-electron lasers (XFELs), which became operational very recently, promise to address this issue. X-ray pulses provided by XFELs are many orders of magnitude more intense than X-ray pulses from a synchrotron source and at the same time as short as only several tens of femtoseconds. Combined with wavelengths in the nm-pm range, XFELs are well-suited to study ultrafast atomic and molecular dynamics. Additionally, the ultrashort pulses can be utilized to circumvent the damage threshold which set a limit to the incident intensity in X-ray diffraction experiments before. At XFELs, though eventually destroying the investigated sample, no significant sample deterioration happens on the ultrashort timescale of the XFEL pulse and the measured diffraction pattern is due to an (almost) unharmed sample. In the framework of this thesis, the approach of utilizing the highly intense XFEL pulses for X-ray diffraction of weakly-scattering non-crystalline samples was taken to the limit of small isolated molecules. X-ray diffraction was

  17. Controlled molecules for X-ray diffraction experiments at free-electron lasers

    Energy Technology Data Exchange (ETDEWEB)

    Stern, Stephan

    2013-12-15

    X-ray diffractive imaging is at the very heart of materials science and has been utilized for decades to solve unknown molecular structures. Nowadays, it serves as the key method of structural biology to solve molecular structures of large biological molecules comprising several thousand or even millions of atoms. However, X-ray diffraction from isolated molecules is very weak. Therefore, the regular and periodic arrangement of a huge number of identical copies of a certain molecule of interest within a crystal lattice has been a necessary condition in order to exploit Bragg diffraction of X-rays. This results in a huge increase in scattered signal and a strongly improved signal-to-noise ratio compared to diffraction from non-crystalline samples. The major bottleneck of structural biology is that many of biologically interesting molecules refuse to form crystals of sufficient size to be used at synchrotron X-ray lightsources. However, novel X-ray free-electron lasers (XFELs), which became operational very recently, promise to address this issue. X-ray pulses provided by XFELs are many orders of magnitude more intense than X-ray pulses from a synchrotron source and at the same time as short as only several tens of femtoseconds. Combined with wavelengths in the nm-pm range, XFELs are well-suited to study ultrafast atomic and molecular dynamics. Additionally, the ultrashort pulses can be utilized to circumvent the damage threshold which set a limit to the incident intensity in X-ray diffraction experiments before. At XFELs, though eventually destroying the investigated sample, no significant sample deterioration happens on the ultrashort timescale of the XFEL pulse and the measured diffraction pattern is due to an (almost) unharmed sample. In the framework of this thesis, the approach of utilizing the highly intense XFEL pulses for X-ray diffraction of weakly-scattering non-crystalline samples was taken to the limit of small isolated molecules. X-ray diffraction was

  18. Aurora laser optical system

    International Nuclear Information System (INIS)

    Hanlon, J.A.; McLeod, J.

    1987-01-01

    Aurora is the Los Alamos short-pulse high-power krypton fluoride laser system. It is primarily an end-to-end technology demonstration prototype for large-scale UV laser systems of interest for short-wavelength inertial confinement fusion (ICF) investigations. The system is designed to employ optical angular multiplexing and aerial amplification by electron-beam-driven KrF laser amplifiers to deliver to ICF targets a stack of pulses with a duration of 5 ns containing several kilojoules at a wavelength of 248 nm. A program of high-energy density plasma physics investigations is now planned, and a sophisticated target chamber was constructed. The authors describe the design of the optical system for Aurora and report its status. This optical system was designed and is being constructed in two phases. The first phase carries only through the amplifier train and does not include a target chamber or any demultiplexing. Installation should be complete, and some performance results should be available. The second phase provides demultiplexing and carries the laser light to target. The complete design is reported

  19. Laser surveillance system (LASSY)

    International Nuclear Information System (INIS)

    Boeck, H.

    1991-09-01

    Laser Surveillance System (LASSY) is a beam of laser light which scans a plane above the water or under-water in a spent-fuel pond. The system can detect different objects and estimates its coordinates and distance as well. LASSY can operate in stand-alone configuration or in combination with a video surveillance to trigger signal to a videorecorder. The recorded information on LASSY computer's disk comprises date, time, start and stop angle of detected alarm, the size of the disturbance indicated in number of deviated points and some other information. The information given by the laser system cannot be fully substituted by TV camera pictures since the scanning beam creates a horizontal surveillance plan. The engineered prototype laser system long-term field test has been carried out in Soluggia (Italy) and has shown its feasibility and reliability under the conditions of real spent fuel storage pond. The verification of the alarm table on the LASSY computer with the recorded video pictures of TV surveillance system confirmed that all alarm situations have been detected. 5 refs

  20. A diffraction limited nitrogen laser for detector calibration in high energy physics

    International Nuclear Information System (INIS)

    Hartjes, F.G.

    1990-01-01

    This thesis consists of two parts. In part I the operation of a pulsed two-stage nitrogen laser is described. In contrast to most other lasers an optical resonator can not be used in a nitrogen laser because of the very short pulse time (∼ 1 ns). Therefore the emitted beam of a simple nitrogen laser has a large divergence. A nitrogen laser with a small beam divergence however can be constructed via the 'Master Oscillator Power Amplifier' principle. Herein a double nitrogen laser system is employed in which both lasers fire simultaneously. The diameter of the laser beam from the first stage (oscillator) is enlarged by a telescope by which the divergence decreases strongly. In a second stage (amplifier) subsequently the weak laser beam is amplified again. The outcoming beam has an elongated diameter which is changed in an approximately round form by a telescope of two cylindrical lenses. The process leading to the formation of population inversion in the nitrogen causing emission of laser ligth is described. The electric circuit, which delivers the high-voltage pulse causing the electric discharge in the laser cavity, is described. The mechanical construction of the laser, in particular with regard to the choices of the materials, is described. Finally, the optical system of the two-stage nitrogen laser is explained. In part II the application of the two-stage nitrogen laser in high-energy physics is treated. Instructions are given about the practical use of the laser: the usual optical system and the ionization profile to be expected in the detector gas. Herein three different kinds of beams are distinguished: the parallel beam, the weakly focussed, and the strongly focussed beam. Some examples are given of the use of the laser: a time very close to the wire, the outlining of the drift wire chambers with a long parallel beam, and the measurement of optical properties of scintillating plastic fibers. (author). 52 refs.; 76 figs.; 4 tabs

  1. Zone-boundary optimization for direct laser writing of continuous-relief diffractive optical elements.

    Science.gov (United States)

    Korolkov, Victor P; Nasyrov, Ruslan K; Shimansky, Ruslan V

    2006-01-01

    Enhancing the diffraction efficiency of continuous-relief diffractive optical elements fabricated by direct laser writing is discussed. A new method of zone-boundary optimization is proposed to correct exposure data only in narrow areas along the boundaries of diffractive zones. The optimization decreases the loss of diffraction efficiency related to convolution of a desired phase profile with a writing-beam intensity distribution. A simplified stepped transition function that describes optimized exposure data near zone boundaries can be made universal for a wide range of zone periods. The approach permits a similar increase in the diffraction efficiency as an individual-pixel optimization but with fewer computation efforts. Computer simulations demonstrated that the zone-boundary optimization for a 6 microm period grating increases the efficiency by 7% and 14.5% for 0.6 microm and 1.65 microm writing-spot diameters, respectively. The diffraction efficiency of as much as 65%-90% for 4-10 microm zone periods was obtained experimentally with this method.

  2. Diffraction of white-light supercontinuum by femtosecond laser-induced transient grating in carbon bisulfide

    International Nuclear Information System (INIS)

    Li, Huang; Yan-Qiang, Yang; Ying-Hui, Wang; Zhi-Ren, Zheng; Wen-Hui, Su

    2010-01-01

    Experiments on fs laser-induced transient grating (LITG) in carbon bisulfide (CS 2 ) are carried out to explore the chirp characteristics of a white-light supercontinuum (SC) generated by a 800-nm, 160-fs laser pulse in a 4-mm thick Al 2 O 3 crystal. Two orders of diffraction signals of SC by fs LITG in CS 2 are observed, demonstrating that both the third-order process and the fifth-order process are present simultaneously. The experimental results also imply that the formation of an fs transient refractive-index grating in CS 2 is mainly due to the electronic polarization process. (classical areas of phenomenology)

  3. Near-field diffraction of laser light by dielectric corner step

    Science.gov (United States)

    Stafeev, S.; Kotlyar, V.; Kovalev, A.

    2014-01-01

    The diffraction of a linearly polarized plane wave by a corner dielectric microstep of height equals of two incident wavelengths was studied using finite-difference time domain method and near-field scanning optical microscopy. It was shown that the corner step generates an elongated region of enhanced intensity, termed as a curved laser microjet. The curved laser microjet has a length of about DOF = 9.5λ and the smallest diameter FWHM = (1.94+/-0.15)λ at distance z = 5.5λ.

  4. Ultrafast electron diffraction from non-equilibrium phonons in femtosecond laser heated Au films

    Energy Technology Data Exchange (ETDEWEB)

    Chase, T. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); Trigo, M.; Reid, A. H.; Dürr, H. A. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Li, R.; Vecchione, T.; Shen, X.; Weathersby, S.; Coffee, R.; Hartmann, N.; Wang, X. J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Reis, D. A. [Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Department of Applied Physics, Stanford University, Stanford, California 94305 (United States); PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States)

    2016-01-25

    We use ultrafast electron diffraction to detect the temporal evolution of non-equilibrium phonons in femtosecond laser-excited ultrathin single-crystalline gold films. From the time-dependence of the Debye-Waller factor, we extract a 4.7 ps time-constant for the increase in mean-square atomic displacements. The observed increase in the diffuse scattering intensity demonstrates that the energy transfer from laser-heated electrons to phonon modes near the X and K points in the Au fcc Brillouin zone proceeds with timescales of 2.3 and 2.9 ps, respectively, faster than the Debye-Waller average mean-square displacement.

  5. Coherent laser vision system

    International Nuclear Information System (INIS)

    Sebastion, R.L.

    1995-01-01

    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

  6. Coherent laser vision system

    Energy Technology Data Exchange (ETDEWEB)

    Sebastion, R.L. [Coleman Research Corp., Springfield, VA (United States)

    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.

  7. Traveling wave laser system

    International Nuclear Information System (INIS)

    Gregg, D.W.; Kidder, R.E.; Biehl, A.T.

    1975-01-01

    The invention broadly involves a method and means for generating a traveling wave laser pulse and is basically analogous to a single pass light amplifier system. However, the invention provides a traveling wave laser pulse of almost unlimited energy content, wherein a gain medium is pumped in a traveling wave mode, the traveling wave moving at essentially the velocity of light to generate an amplifying region or zone which moves through the medium at the velocity of light in the presence of directed stimulating radiation, thereby generating a traveling coherent, directed radiation pulse moving with the amplification zone through the gain medium. (U.S.)

  8. Genetic algorithm for the design of high frequency diffraction gratings for high power laser applications

    Science.gov (United States)

    Thomson, Martin J.; Waddie, Andrew J.; Taghizadeh, Mohammad R.

    2006-04-01

    We present a genetic algorithm with small population sizes for the design of diffraction gratings in the rigorous domain. A general crossover and mutation scheme is defined, forming fifteen offspring from 3 parents, which enables the algorithm to be used for designing gratings with diverse optical properties by careful definition of the merit function. The initial parents are randomly selected and the parents of the subsequent generations are selected by survival of the fittest. The performance of the algorithm is demonstrated by designing diffraction gratings with specific application to high power laser beam lines. Gratings are designed that act as beam deflectors, polarisers, polarising beam splitters, harmonic separation gratings and pulse compression gratings. By imposing fabrication constraints within the design process, we determine which of these elements have true potential for application within high power laser beam lines.

  9. UV-laser-based longitudinal illuminated diffuser (LID) incorporating diffractive and Lambertian reflectance for the disinfection of beverages

    Science.gov (United States)

    Lizotte, Todd

    2010-08-01

    A novel laser beam shaping system was designed to demonstrate the potential of using high power UV laser sources for large scale disinfection of liquids used in the production of food products, such as juices, beer, milk and other beverage types. The design incorporates a patented assembly of optical components including a diffractive beam splitting/shaping element and a faceted pyramidal or conically shaped Lambertian diffuser made from a compression molded PTFE compounds. When properly sintered to an appropriate density, as an example between 1.10 and 1.40 grams per cubic centimeter, the compressed PTFE compounds show a ~99% reflectance at wavelengths ranging from 300 nm to 1500 nm, and a ~98.5% refection of wavelengths from 250 nm to 2000 nm [1]. The unique diffuser configuration also benefits from the fact that the PTFE compounds do not degrade when exposed to ultraviolet radiation as do barium sulfate materials and silver or aluminized mirror coatings [2]. These components are contained within a hermetically sealed quartz tube. Once assembled a laser beam is directed through one end of the tube. This window takes the form of a computer generated diffractive splitter or other diffractive shaper element to split the laser beam into a series of spot beamlets, circular rings or other geometric shapes. As each of the split beamlets or rings cascade downward, they illuminate various points along the tapered PTFE cone or faceted pyramidal form. As they strike the surface they each diffuse in a Lambertian reflectance pattern creating a pseudo-uniform circumferential illuminator along the length of the quartz tube enclosing the assembly. The compact tubular structure termed Longitudinal Illuminated Diffuser (LID) provides a unique UV disinfection source that can be placed within a centrifugal reactor or a pipe based reactor chamber. This paper will review the overall design principle, key component design parameters, preliminary analytic and bench operational testing

  10. Ultrafast coherent diffractive imaging of nanoparticles using X-ray free-electron laser radiation

    International Nuclear Information System (INIS)

    Kassemeyer, Stephan

    2014-01-01

    Coherent diffractive imaging with X-ray free-electron lasers (X-FEL) promises high-resolution structure determination of single microscopic particles without the need for crystallization. The diffraction signal of small samples can be very weak, a difficulty that can not be countered by merely increasing the number of photons because the sample would be damaged by a high absorbed radiation dose. Traditional X-ray crystallography avoids this problem by bringing many sample particles into a periodic arrangement, which amplifies the individual signals while distributing the absorbed dose. Depending on the sample, however, crystallization can be very difficult or even impossible. This thesis presents algorithms for a new imaging approach using X-FEL radiation that works with single, non-crystalline sample particles. X-FELs can deliver X-rays with a peak brilliance many orders of magnitude higher than conventional X-ray sources, compensating for their weak interaction cross sections. At the same time, FELs can produce ultra-short pulses down to a few femtoseconds. In this way it is possible to perform ultra-fast imaging, essentially ''freezing'' the atomic positions in time and terminating the imaging process before the sample is destroyed by the absorbed radiation. This thesis primarily focuses on the three-dimensional reconstruction of single (and not necessarily crystalline) particles using coherent diffractive imaging at X-FELs: in order to extract three-dimensional information from scattering data, two-dimensional diffraction patterns from many different viewing angles must be combined. Therefore, the diffraction signal of many identical sample copies in random orientations is measured. The main result of this work is a globally optimal algorithm that can recover the sample orientations solely based on the diffraction signal, enabling three-dimensional imaging for arbitrary samples. The problem of finding three-dimensional orientations is

  11. Diffraction of a Gaussian laser beam by a straight edge leading to the formation of optical vortices and elliptical diffraction fringes

    Science.gov (United States)

    Zeylikovich, Iosif; Nikitin, Aleksandr

    2018-04-01

    The diffraction of a Gaussian laser beam by a straight edge has been studied theoretically and experimentally for many years. In this paper, we have experimentally observed for the first time the formation of the cusped caustic (for the Fresnel number F ≈ 100) in the shadow region of the straight edge, with the cusp placed near the center of the circular laser beam(λ = 0 . 65 μm) overlapped with the elliptical diffraction fringes. These fringes are originated at the region near the cusp of the caustic where light intensity is zero and the wave phase is singular (the optical vortex). We interpret observed diffraction fringes as a result of interference between the helical wave created by the optical vortex and cylindrical wave diffracted at the straight edge. We have theoretically revealed that the number of high contrast diffraction fringes observable in a shadow region is determined by the square of the diffracted angles in the range of spatial frequencies of the scattered light field in excellent agreement with experiments. The extra phase singularities with opposite charges are also observed along the shadow boundary as the fork-like diffraction fringes.

  12. Femtosecond laser induced tunable surface transformations on (111) Si aided by square grids diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Han, Weina; Jiang, Lan; Li, Xiaowei, E-mail: lixiaowei@bit.edu.cn; Liu, Yang [Laser Micro/Nano-Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081 (China); Lu, Yongfeng [Department of Electrical Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588-0511 (United States)

    2015-12-21

    We report an extra freedom to modulate the femtosecond laser energy distribution to control the surface ablated structures through a copper-grid mask. Due to the reduced deposited pulse energy by changing the scanning speed or the pulse fluence, a sequential evolution of three distinctly different surface patterns with periodic distributions is formed, namely, striped ripple lines, ripple microdots, and surface modification. By changing the scanning speed, the number of the multiple dots in a lattice can be modulated. Moreover, by exploring the ablation process through the copper grid mask, it shows an abnormal enhanced ablation effect with strong dependence of the diffraction-aided fs laser ablated surface structures on polarization direction. The sensitivity shows a quasi-cosinusoid-function with a periodicity of π/2. Particularly, the connection process of striped ripple lines manifests a preferential formation direction with the laser polarization.

  13. 1-W quasi-cw near-diffraction-limited semiconductor laser pumped optically by a fibre-coupled diode bar

    OpenAIRE

    Dhanjal, S.; Hoogland, S.; Roberts, J.S.; Hayward, R.A.; Clarkson, W.A.; Tropper, Anne

    2000-01-01

    We describe a diode-bar-pumped vertical-external-cavity surface-emitting semiconductor laser, which in quasi-cw operation emitted a peak power of >1 W at 1020 nm in a circular, near diffraction-limited beam.

  14. Grey signal processing and data reconstruction in the non-diffracting beam triangulation measurement system

    Science.gov (United States)

    Meng, Hao; Wang, Zhongyu; Fu, Jihua

    2008-12-01

    The non-diffracting beam triangulation measurement system possesses the advantages of longer measurement range, higher theoretical measurement accuracy and higher resolution over the traditional laser triangulation measurement system. Unfortunately the measurement accuracy of the system is greatly degraded due to the speckle noise, the CCD photoelectric noise and the background light noise in practical applications. Hence, some effective signal processing methods must be applied to improve the measurement accuracy. In this paper a novel effective method for removing the noises in the non-diffracting beam triangulation measurement system is proposed. In the method the grey system theory is used to process and reconstruct the measurement signal. Through implementing the grey dynamic filtering based on the dynamic GM(1,1), the noises can be effectively removed from the primary measurement data and the measurement accuracy of the system can be improved as a result.

  15. PEP Laser Surveying System

    International Nuclear Information System (INIS)

    Lauritzen, T.; Sah, R.C.

    1979-03-01

    A Laser Surveying System has been developed to survey the beam elements of the PEP storage ring. This system provides automatic data acquisition and analysis in order to increase survey speed and to minimize operator error. Two special instruments, the Automatic Readout Micrometer and the Small Automatic Micrometer, have been built for measuring the locations of fiducial points on beam elements with respect to the light beam from a laser. These instruments automatically encode offset distances and read them into the memory of an on-line computer. Distances along the beam line are automatically encoded with a third instrument, the Automatic Readout Tape Unit. When measurements of several beam elements have been taken, the on-line computer analyzes the measured data, compared them with desired parameters, and calculates the required adjustments to beam element support stands

  16. Optically pumped laser systems

    International Nuclear Information System (INIS)

    DeMaria, A.J.; Mack, M.E.

    1975-01-01

    Laser systems which are pumped by an electric discharge formed in a gas are disclosed. The discharge is in the form of a vortex stabilized electric arc which is triggered with an auxiliary energy source. At high enough repetition rates residual ionization between successive pulses contributes to the pulse stabilization. The arc and the gain medium are positioned inside an optical pumping cavity where light from the arc is coupled directly into the gain medium

  17. Safety and efficacy of a novel diffractive lens array using a picosecond 755?nm alexandrite laser for treatment of wrinkles

    OpenAIRE

    Weiss, Robert A.; McDaniel, David H.; Weiss, Margaret A.; Mahoney, Anne Marie; Beasley, Karen L.; Halvorson, Christian R.

    2016-01-01

    Introduction Picosecond lasers have been reported to be effective for removal of tattoo pigment. This prospective study evaluated the efficacy and safety of the treatment of peri?oral and ?ocular wrinkles using a novel diffractive lens array coupled with a picosecond 755?nm alexandrite laser. Methods Forty female subjects presenting with wrinkles from photodamage were enrolled in an IRB approved study. Subjects received four picosecond diffractive lens array treatments to the full face at 1 m...

  18. Measurement system for diffraction efficiency of convex gratings

    Science.gov (United States)

    Liu, Peng; Chen, Xin-hua; Zhou, Jian-kang; Zhao, Zhi-cheng; Liu, Quan; Luo, Chao; Wang, Xiao-feng; Tang, Min-xue; Shen, Wei-min

    2017-08-01

    A measurement system for diffraction efficiency of convex gratings is designed. The measurement system mainly includes four components as a light source, a front system, a dispersing system that contains a convex grating, and a detector. Based on the definition and measuring principle of diffraction efficiency, the optical scheme of the measurement system is analyzed and the design result is given. Then, in order to validate the feasibility of the designed system, the measurement system is set up and the diffraction efficiency of a convex grating with the aperture of 35 mm, the curvature-radius of 72mm, the blazed angle of 6.4°, the grating period of 2.5μm and the working waveband of 400nm-900nm is tested. Based on GUM (Guide to the Expression of Uncertainty in Measurement), the uncertainties in the measuring results are evaluated. The measured diffraction efficiency data are compared to the theoretical ones, which are calculated based on the grating groove parameters got by an atomic force microscope and Rigorous Couple Wave Analysis, and the reliability of the measurement system is illustrated. Finally, the measurement performance of the system is analyzed and tested. The results show that, the testing accuracy, the testing stability and the testing repeatability are 2.5%, 0.085% and 3.5% , respectively.

  19. Diffraction scattering of strongly bound system

    International Nuclear Information System (INIS)

    Kuzmichev, V.E.

    1982-04-01

    The scattering of a hadron on a strongly bound system of two hadrons (dihadron) is considered in the high-energy limit for the relative hadron-dihadron motion. The dihadron scatterer motion and the internal interaction are included in our consideration. It is shown that only small values of the internal transfer momentum of dihadron particles bring the principal contribution to the three-particle propagator in eikonal approximation. On the basis of the exact analytical solution of the integral equation for the total Green function the scattering amplitude is derived. It is shown that the scattering amplitude contains only single, double, and triple scattering terms. The three new terms to the Glauber formula for the total cross section are obtained. These terms decrease both the true total hadron-hadron cross section and the screening correction. (orig.)

  20. Recent advance to 3 × 10(-5) rad near diffraction-limited beam divergence of dye laser with transverse-discharge flash-lamp pumping.

    Science.gov (United States)

    Trusov, K K

    1994-02-20

    A new experimental setup of a Rhodamine 6G dye laser with a transverse-discharge flash-lamp-pumping system is presented. It differs from a previous setup [Sov. J. Quantum Electron. 16, 468-471 (1989)] in that it has a larger laser beam aperture (32 mm) and higher pumping energy (1 kJ), which made it possible to test the scalability and reach near diffraction-limited laser beam divergence of 3 × 10(-5) rad FWHM at beam energy 1.4 J. The effect of spectral dispersion in the active medium and of other optical elements on the beam divergence is also discussed.

  1. The Final Focus Test Beam laser referene system

    International Nuclear Information System (INIS)

    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

  2. Application of Various Lasers to Laser Trimming Resistance System

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-feng

    2007-01-01

    Though the laser trimming resistance has been an old laser machining industry for over 30 years, the development of technology brings new alternative lasers which can be used for the traditional machining. The paper describes application of various lasers to laser trimming resistance system including early traditional krypton arc lamp pumped Nd:YAG to laser, modern popular diode pumped solid state laser and the present advanced harmonic diode pumped solid state laser. Using the new alternative lasers in the laser trimming resistance system can dramatically improve the yields and equipment performance.

  3. Laser system using ultra-short laser pulses

    Science.gov (United States)

    Dantus, Marcos [Okemos, MI; Lozovoy, Vadim V [Okemos, MI; Comstock, Matthew [Milford, MI

    2009-10-27

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

  4. Modeling focusing characteristics of low Fnumber diffractive optical elements with continuous relief fabricated by laser direct writing.

    Science.gov (United States)

    Shan, Mingguang; Tan, Jiubin

    2007-12-10

    A theoretical model is established using Rayleigh-Sommerfeld diffraction theory to describe the diffraction focusing characteristics of low F-number diffractive optical elements with continuous relief fabricated by laser direct writing, and continuous-relief diffractive optical elements with a design wavelength of 441.6nm and a F-number of F/4 are fabricated and measured to verify the validity of the diffraction focusing model. The measurements made indicate that the spot size is 1.75mum and the diffraction efficiency is 70.7% at the design wavelength, which coincide well with the theoretical results: a spot size of 1.66mum and a diffraction efficiency of 71.2%.

  5. High throughput diffractive multi-beam femtosecond laser processing using a spatial light modulator

    Energy Technology Data Exchange (ETDEWEB)

    Kuang Zheng [Laser Group, Department of Engineering, University of Liverpool Brownlow Street, Liverpool L69 3GQ (United Kingdom)], E-mail: z.kuang@liv.ac.uk; Perrie, Walter [Laser Group, Department of Engineering, University of Liverpool Brownlow Street, Liverpool L69 3GQ (United Kingdom); Leach, Jonathan [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Sharp, Martin; Edwardson, Stuart P. [Laser Group, Department of Engineering, University of Liverpool Brownlow Street, Liverpool L69 3GQ (United Kingdom); Padgett, Miles [Department of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ (United Kingdom); Dearden, Geoff; Watkins, Ken G. [Laser Group, Department of Engineering, University of Liverpool Brownlow Street, Liverpool L69 3GQ (United Kingdom)

    2008-12-30

    High throughput femtosecond laser processing is demonstrated by creating multiple beams using a spatial light modulator (SLM). The diffractive multi-beam patterns are modulated in real time by computer generated holograms (CGHs), which can be calculated by appropriate algorithms. An interactive LabVIEW program is adopted to generate the relevant CGHs. Optical efficiency at this stage is shown to be {approx}50% into first order beams and real time processing has been carried out at 50 Hz refresh rate. Results obtained demonstrate high precision surface micro-structuring on silicon and Ti6Al4V with throughput gain >1 order of magnitude.

  6. X-ray diffraction in laser-irradiated epsomite crystals grown in presence of borax

    International Nuclear Information System (INIS)

    Zaitseva, E.V.; Portnov, V.N.; Faddeev, M.A.; Chuprunov, E.V.

    1997-01-01

    Relative changes in the intensities ΔI/I of the (220) and (440) X-ray diffraction reflection during laser irradiation of epsomite (MgSO 2 ·7H 2 O) crystals grown from an aqueous solution in the presence of borax (Na 2 B 4 O 7 ·10H 2 O) were measured using the CoK α , CuK α , MoK α radiations. The intensities measured depend on the real crystal structure dependent on the borax content in the solution. The dependence of ΔI/I is studied as a function of borax in the solution and X-ray-radiation wavelength

  7. Strategies for Time-resolved X-ray Diffraction of Phase Transitions with Laser Compression

    Science.gov (United States)

    Benedetti, Laura Robin; Eggert, J. H.; Bradley, D. K.; Bell, P. M.; Kilkenny, J. D.; Palmer, N.; Petre, R. B.; Rygg, J. R.; Sorce, C.; Collins, G. W.; Boehly, T. R.

    2017-10-01

    As part of a program to document kinetics of phase transitions under laser-driven dynamic compression, we are designing a platform to make multiple x-ray diffraction measurements during a single laser experiment. Our plans include experimental development at Omega-EP and eventual implementation at NIF. We will present our strategy for designing a robust platform that can effectively document a wide variety of phase transformations by utilizing both streaked and multiple-frame imaging detectors. Preliminary designs utilize a novel CMOS detector designed by Sandia National Lab. Our initial experiments include scoping studies that will focus on photometrics and shielding requirements in the high EMP environment close to the target. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. Lawrence Livermore National Security, LLC, LLNL-ABS-734470.

  8. Efficient concept for generation of diffraction-limited green light by sum-frequency generation of spectrally combined tapered diode lasers

    DEFF Research Database (Denmark)

    Müller, André; Jensen, Ole Bjarlin; Hasler, Karl-Heinz

    2012-01-01

    In order to increase the power of visible diode laser systems in an efficient manner, we propose spectral beam combining with subsequent sum-frequency generation. We show that this approach, in comparison with second harmonic generation of single emitters, can enhance the available power signific......In order to increase the power of visible diode laser systems in an efficient manner, we propose spectral beam combining with subsequent sum-frequency generation. We show that this approach, in comparison with second harmonic generation of single emitters, can enhance the available power...... significantly. By combining two distributed Bragg reflector tapered diode lasers we achieve a 2.5–3.2 fold increase in power and a maximum of 3.9 W of diffraction-limited green light. At this power level, green diode laser systems have a high application potential, e.g., within the biomedical field. Our concept...

  9. Laser engineering of microbial systems

    Science.gov (United States)

    Yusupov, V. I.; Gorlenko, M. V.; Cheptsov, V. S.; Minaev, N. V.; Churbanova, E. S.; Zhigarkov, V. S.; Chutko, E. A.; Evlashin, S. A.; Chichkov, B. N.; Bagratashvili, V. N.

    2018-06-01

    A technology of laser engineering of microbial systems (LEMS) based on the method of laser-induced transfer of heterogeneous mixtures containing microorganisms (laser bioprinting) is described. This technology involves laser printing of soil microparticles by focusing near-infrared laser pulses on a specially prepared gel/soil mixture spread onto a gold-coated glass plate. The optimal range of laser energies from the point of view of the formation of stable jets and droplets with minimal negative impact on living systems of giant accelerations, laser pulse irradiation, and Au nanoparticles was found. Microsamples of soil were printed on glucose-peptone-yeast agar plates to estimate the LEMS process influence on structural and morphological microbial diversity. The obtained results were compared with traditionally treated soil samples. It was shown that LEMS technology allows significantly increasing the biodiversity of printed organisms and is effective for isolating rare or unculturable microorganisms.

  10. Diffraction measurements using the LHC Beam Loss Monitoring System

    Science.gov (United States)

    Kalliokoski, Matti

    2017-03-01

    The Beam Loss Monitoring (BLM) system of the Large Hadron Collider protects the machine from beam induced damage by measuring the absorbed dose rates of beam losses, and by triggering beam dump if the rates increase above the allowed threshold limits. Although the detection time scales are optimized for multi-turn losses, information on fast losses can be recovered from the loss data. In this paper, methods in using the BLM system in diffraction studies are discussed.

  11. Intraocular camera for retinal prostheses: Refractive and diffractive lens systems

    Science.gov (United States)

    Hauer, Michelle Christine

    The focus of this thesis is on the design and analysis of refractive, diffractive, and hybrid refractive/diffractive lens systems for a miniaturized camera that can be surgically implanted in the crystalline lens sac and is designed to work in conjunction with current and future generation retinal prostheses. The development of such an intraocular camera (IOC) would eliminate the need for an external head-mounted or eyeglass-mounted camera. Placing the camera inside the eye would allow subjects to use their natural eye movements for foveation (attention) instead of more cumbersome head tracking, would notably aid in personal navigation and mobility, and would also be significantly more psychologically appealing from the standpoint of personal appearances. The capability for accommodation with no moving parts or feedback control is incorporated by employing camera designs that exhibit nearly infinite depth of field. Such an ultracompact optical imaging system requires a unique combination of refractive and diffractive optical elements and relaxed system constraints derived from human psychophysics. This configuration necessitates an extremely compact, short focal-length lens system with an f-number close to unity. Initially, these constraints appear highly aggressive from an optical design perspective. However, after careful analysis of the unique imaging requirements of a camera intended to work in conjunction with the relatively low pixellation levels of a retinal microstimulator array, it becomes clear that such a design is not only feasible, but could possibly be implemented with a single lens system.

  12. Diffraction gauging

    International Nuclear Information System (INIS)

    Wilkens, P.H.

    1978-01-01

    This system of gauging is now being designed to fit on an Excello NC lathe to measure the form, accuracy, and size of external contoured surfaces as they approach the finish machined size. A template profile of the finished workpiece, but 0.003 in. bigger on radius, will be aligned with the workpiece using a reference diameter and face on the machining fixture to leave a gap between the profile of the template and workpiece. A helium--neon laser beam will be projected through this gap using a rotating retroreflector and a fixed laser. The resulting diffraction pattern produced by the laser beam passing through the template to workpiece gap will be reflected and focused on a fixed diode array via a second retroreflector which moves and remains in optical alignment with the first. These retroreflectors will be rotated about a center that will enable the laser beam, which is shaped in a long slit, to scan the template workpiece gap from the pole to the equator of the workpiece. The characteristic diffraction pattern will be detected by the fixed diode array, and the signal levels from this array will be processed in a mini-computer programmed to produce a best fit through the two minima of the diode signals. The separation of the two minima will yield the size of the workpiece to template gap and this information will be presented to the machine tool operator

  13. Observation of coherent optical phonons excited by femtosecond laser radiation in Sb films by ultrafast electron diffraction method

    Energy Technology Data Exchange (ETDEWEB)

    Mironov, B. N.; Kompanets, V. O.; Aseev, S. A., E-mail: isanfemto@yandex.ru [Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation); Ischenko, A. A. [Moscow Technological University, Institute of High Chemical Technologies (Russian Federation); Kochikov, I. V. [Moscow State University (Russian Federation); Misochko, O. V. [Russian Academy of Sciences, Institute of Solid State Physics (Russian Federation); Chekalin, S. V.; Ryabov, E. A. [Russian Academy of Sciences, Institute of Spectroscopy (Russian Federation)

    2017-03-15

    The generation of coherent optical phonons in a polycrystalline antimony film sample has been investigated using femtosecond electron diffraction method. Phonon vibrations have been induced in the Sb sample by the main harmonic of a femtosecond Ti:Sa laser (λ = 800 nm) and probed by a pulsed ultrashort photoelectron beam synchronized with the pump laser. The diffraction patterns recorded at different times relative to the pump laser pulse display oscillations of electron diffraction intensity corresponding to the frequencies of vibrations of optical phonons: totally symmetric (A{sub 1g}) and twofold degenerate (E{sub g}) phonon modes. The frequencies that correspond to combinations of these phonon modes in the Sb sample have also been experimentally observed.

  14. Diffractive optics for reduction of hot cracking in pulsed mode Nd:YAG laser welding

    DEFF Research Database (Denmark)

    Bagger, Claus; Olesen, Søren; Roos, Sven-Olov

    2001-01-01

    In order to reduce the susceptibility to hot cracking in pulsed mode laser welding of austenitic stainless steel, an optical system for reduction of the cooling rate is sought developed. Based on intensive numerical simulations, an optical system producing three focused spots is made. In a number...

  15. Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate

    Science.gov (United States)

    He, Z.-H.; Thomas, A. G. R.; Beaurepaire, B.; Nees, J. A.; Hou, B.; Malka, V.; Krushelnick, K.; Faure, J.

    2013-02-01

    We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

  16. Electron diffraction using ultrafast electron bunches from a laser-wakefield accelerator at kHz repetition rate

    Energy Technology Data Exchange (ETDEWEB)

    He, Z.-H.; Thomas, A. G. R.; Nees, J. A.; Hou, B.; Krushelnick, K. [Center for Ultrafast Optical Science, University of Michigan, Ann Arbor, Michigan 48106-2099 (United States); Beaurepaire, B.; Malka, V.; Faure, J. [Laboratoire d' Optique Appliquee, ENSTA-CNRS-Ecole Polytechnique, UMR 7639, 91761 Palaiseau (France)

    2013-02-11

    We show that electron bunches in the 50-100 keV range can be produced from a laser wakefield accelerator using 10 mJ, 35 fs laser pulses operating at 0.5 kHz. It is shown that using a solenoid magnetic lens, the electron bunch distribution can be shaped. The resulting transverse and longitudinal coherence is suitable for producing diffraction images from a polycrystalline 10 nm aluminum foil. The high repetition rate, the stability of the electron source, and the fact that its uncorrelated bunch duration is below 100 fs make this approach promising for the development of sub-100 fs ultrafast electron diffraction experiments.

  17. X-ray laser diffraction for structure determination of the rhodopsin-arrestin complex

    Science.gov (United States)

    Zhou, X. Edward; Gao, Xiang; Barty, Anton; Kang, Yanyong; He, Yuanzheng; Liu, Wei; Ishchenko, Andrii; White, Thomas A.; Yefanov, Oleksandr; Han, Gye Won; Xu, Qingping; de Waal, Parker W.; Suino-Powell, Kelly M.; Boutet, Sébastien; Williams, Garth J.; Wang, Meitian; Li, Dianfan; Caffrey, Martin; Chapman, Henry N.; Spence, John C. H.; Fromme, Petra; Weierstall, Uwe; Stevens, Raymond C.; Cherezov, Vadim; Melcher, Karsten; Xu, H. Eric

    2016-04-01

    Serial femtosecond X-ray crystallography (SFX) using an X-ray free electron laser (XFEL) is a recent advancement in structural biology for solving crystal structures of challenging membrane proteins, including G-protein coupled receptors (GPCRs), which often only produce microcrystals. An XFEL delivers highly intense X-ray pulses of femtosecond duration short enough to enable the collection of single diffraction images before significant radiation damage to crystals sets in. Here we report the deposition of the XFEL data and provide further details on crystallization, XFEL data collection and analysis, structure determination, and the validation of the structural model. The rhodopsin-arrestin crystal structure solved with SFX represents the first near-atomic resolution structure of a GPCR-arrestin complex, provides structural insights into understanding of arrestin-mediated GPCR signaling, and demonstrates the great potential of this SFX-XFEL technology for accelerating crystal structure determination of challenging proteins and protein complexes.

  18. Optical system storage design with diffractive optical elements

    Science.gov (United States)

    Kostuk, Raymond K.; Haggans, Charles W.

    1993-01-01

    Optical data storage systems are gaining widespread acceptance due to their high areal density and the ability to remove the high capacity hard disk from the system. In magneto-optical read-write systems, a small rotation of the polarization state in the return signal from the MO media is the signal which must be sensed. A typical arrangement used for detecting these signals and correcting for errors in tracking and focusing on the disk is illustrated. The components required to achieve these functions are listed. The assembly and alignment of this complex system has a direct impact on cost, and also affects the size, weight, and corresponding data access rates. As a result, integrating these optical components and improving packaging techniques is an active area of research and development. Most designs of binary optic elements have been concerned with optimizing grating efficiency. However, rigorous coupled wave models for vector field diffraction from grating surfaces can be extended to determine the phase and polarization state of the diffracted field, and the design of polarization components. A typical grating geometry and the phase and polarization angles associated with the incident and diffracted fields are shown. In our current stage of work, we are examining system configurations which cascade several polarization functions on a single substrate. In this design, the beam returning from the MO disk illuminates a cascaded grating element which first couples light into the substrate, then introduces a quarter wave retardation, then a polarization rotation, and finally separates s- and p-polarized fields through a polarization beam splitter. The input coupler and polarization beam splitter are formed in volume gratings, and the two intermediate elements are zero-order elements.

  19. Design and fabrication of micro X-ray diffraction system

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yang Soon; Han, Sun Ho; Kim, Jong Goo; Jee, Kwang Yong

    2006-10-15

    It has been observed that microstructure changes occur at the pellet periphery(rim) of the fuel at very high burn-up. Despite its narrow range (below some hundreds microns in depth), this peripheral region(rim) determines the behaviour of nuclear fuel. To determine lattice parameter with XRD at intervals as small as 30-50 {mu} m in radial direction of irradiated fuel samples, a micro X-ray diffraction system was designed and fabricated. This report describes the micro X-ray diffraction system consisted of an X-ray microbeam alignment system and a sample micro translation system, its characterization, and its performance test through the analysis for the micro region of some specimens. This system will be set in a radiation shielded glove box, and then used for analysis of lattice parameter change and the phase change at intervals as small as 30-50 {mu} m in radial direction of the rim of an irradiated fuel sample and a fuel cladding.

  20. Design and fabrication of micro X-ray diffraction system

    International Nuclear Information System (INIS)

    Park, Yang Soon; Han, Sun Ho; Kim, Jong Goo; Jee, Kwang Yong

    2006-10-01

    It has been observed that microstructure changes occur at the pellet periphery(rim) of the fuel at very high burn-up. Despite its narrow range (below some hundreds microns in depth), this peripheral region(rim) determines the behaviour of nuclear fuel. To determine lattice parameter with XRD at intervals as small as 30-50 μ m in radial direction of irradiated fuel samples, a micro X-ray diffraction system was designed and fabricated. This report describes the micro X-ray diffraction system consisted of an X-ray microbeam alignment system and a sample micro translation system, its characterization, and its performance test through the analysis for the micro region of some specimens. This system will be set in a radiation shielded glove box, and then used for analysis of lattice parameter change and the phase change at intervals as small as 30-50 μ m in radial direction of the rim of an irradiated fuel sample and a fuel cladding

  1. High-precision laser microcutting and laser microdrilling using diffractive beam-splitting and high-precision flexible beam alignment

    Science.gov (United States)

    Zibner, F.; Fornaroli, C.; Holtkamp, J.; Shachaf, Lior; Kaplan, Natan; Gillner, A.

    2017-08-01

    High-precision laser micro machining gains more importance in industrial applications every month. Optical systems like the helical optics offer highest quality together with controllable and adjustable drilling geometry, thus as taper angle, aspect ratio and heat effected zone. The helical optics is based on a rotating Dove-prism which is mounted in a hollow shaft engine together with other optical elements like wedge prisms and plane plates. Although the achieved quality can be interpreted as extremely high the low process efficiency is a main reason that this manufacturing technology has only limited demand within the industrial market. The objective of the research studies presented in this paper is to dramatically increase process efficiency as well as process flexibility. During the last years, the average power of commercial ultra-short pulsed laser sources has increased significantly. The efficient utilization of the high average laser power in the field of material processing requires an effective distribution of the laser power onto the work piece. One approach to increase the efficiency is the application of beam splitting devices to enable parallel processing. Multi beam processing is used to parallelize the fabrication of periodic structures as most application only require a partial amount of the emitted ultra-short pulsed laser power. In order to achieve highest flexibility while using multi beam processing the single beams are diverted and re-guided in a way that enables the opportunity to process with each partial beam on locally apart probes or semimanufactures.

  2. Regenerative laser system

    International Nuclear Information System (INIS)

    Biancardi, F.R.; Landerman, A.; Melikian, G.

    1975-01-01

    Regenerative apparatus for exhausting the working medium from the optical cavity of a laser and for supplying preheated diluent to the reaction chamber of a laser is disclosed. In an aftercooler thermal energy is exchanged between the working medium exhausted from the optical cavity and a cryogenic coolant which is subsequently utilized as the motive fluid for an ejector and as a diluent in the production of laser gas. Highly toxic and corrosive gases are condensed out of the working medium as the cryogenic coolant is evaporated and superheated. A preheater transfers additional heat to the diluent before the diluent enters the reaction chamber. (U.S.)

  3. Development and beyond: Strategy for long-term maintenance of an online laser diffraction particle size method in a spray drying manufacturing process.

    Science.gov (United States)

    Medendorp, Joseph; Bric, John; Connelly, Greg; Tolton, Kelly; Warman, Martin

    2015-08-10

    The purpose of this manuscript is to present the intended use and long-term maintenance strategy of an online laser diffraction particle size method used for process control in a spray drying process. A Malvern Insitec was used for online particle size measurements and a Malvern Mastersizer was used for offline particle size measurements. The two methods were developed in parallel with the Mastersizer serving as the reference method. Despite extensive method development across a range of particle sizes, the two instruments demonstrated different sensitivities to material and process changes over the product lifecycle. This paper will describe the procedure used to ensure consistent alignment of the two methods, thus allowing for continued use of online real-time laser diffraction as a surrogate for the offline system over the product lifecycle. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Improving the laser brightness of a commercial laser system

    Science.gov (United States)

    Naidoo, Darryl; Litvin, Igor; Forbes, Andrew

    2016-02-01

    We investigate the selection of a flat-top beam and a Gaussian beam inside a laser cavity on opposing mirrors. The concept is tested external to the laser cavity in a single pass and double pass regime where the latter mimics a single round trip in the laser. We implement this intra-cavity selection through the use of two 16 level diffractive optical elements. We consider a solid-state diode side-pumped laser resonator in a typical commercial laser configuration that consists of two planar mirrors where the DOEs are positioned at the mirrors. We out couple the Gaussian and flat-top distributions and we show that we improve the brightness of the laser with active mode control. We also demonstrate that the quality of the beam transformations determine the brightness improvement.

  5. The GEO 600 laser system

    CERN Document Server

    Zawischa, I; Danzmann, K; Fallnich, C; Heurs, M; Nagano, S; Quetschke, V; Welling, H; Willke, B

    2002-01-01

    Interferometric gravitational wave detectors require high optical power, single frequency lasers with very good beam quality and high amplitude and frequency stability as well as high long-term reliability as input light source. For GEO 600 a laser system with these properties is realized by a stable planar, longitudinally pumped 12 W Nd:YAG rod laser which is injection-locked to a monolithic 800 mW Nd:YAG non-planar ring oscillator. Frequency control signals from the mode cleaners are fed to the actuators of the non-planar ring oscillator which determines the frequency stability of the system. The system power stabilization acts on the slave laser pump diodes which have the largest influence on the output power. In order to gain more output power, a combined Nd:YAG-Nd:YVO sub 4 system is scaled to more than 22 W.

  6. Nova laser alignment control system

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  7. Laser Pyro System Standardization and Man Rating

    Science.gov (United States)

    Brown, Christopher W.

    2004-01-01

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

  8. Traveling wave laser system

    International Nuclear Information System (INIS)

    Gregg, D.W.; Kidder, R.E.; Biehl, A.T.

    1975-01-01

    A method is described for generating a traveling wave laser pulse of almost unlimited energy content wherein a gain medium is pumped into a traveling wave mode, the traveling wave moving at essentially the velocity of light to generate an amplifying region or zone which moves through the medium at the velocity of light in the presence of directed stimulating radiation, thereby generating a traveling coherent, directed radiation pulse moving with the amplification zone through the gain medium. (U.S.)

  9. Development of a high repetition rate laser-plasma accelerator for ultra-fast electron diffraction experiments

    International Nuclear Information System (INIS)

    Beaurepaire, B.

    2009-01-01

    Electronic microscopy and electron diffraction allowed the understanding of the organization of atoms in matter. Using a temporally short source, one can measure atomic displacements or modifications of the electronic distribution in matter. To date, the best temporal resolution for time resolved diffraction experiments is of the order of a hundred femto-seconds (fs). Laser accelerators are good candidates to reach the femtosecond temporal resolution in electron diffraction experiments. Such accelerators used to work at a low repetition rate, so that it was necessary to develop a new one operating at a high repetition rate in order to accumulate a large amount of data. In this thesis, a laser-plasma accelerator operating at the kHz repetition rate was developed and built. This source generates electron bunches at 100 keV from 3 mJ and 25 fs laser pulses. The physics of the acceleration has been studied, and the effect of the laser wavefront on the electron transverse distribution has been demonstrated. (author)

  10. Underwater laser imaging system (UWLIS)

    Energy Technology Data Exchange (ETDEWEB)

    DeLong, M. [Lawrence Livermore National Lab., CA (United States)

    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.

  11. Data processing software suite SITENNO for coherent X-ray diffraction imaging using the X-ray free-electron laser SACLA

    International Nuclear Information System (INIS)

    Sekiguchi, Yuki; Oroguchi, Tomotaka; Takayama, Yuki; Nakasako, Masayoshi

    2014-01-01

    The software suite SITENNO is developed for processing diffraction data collected in coherent X-ray diffraction imaging experiments of non-crystalline particles using an X-ray free-electron laser. Coherent X-ray diffraction imaging is a promising technique for visualizing the structures of non-crystalline particles with dimensions of micrometers to sub-micrometers. Recently, X-ray free-electron laser sources have enabled efficient experiments in the ‘diffraction before destruction’ scheme. Diffraction experiments have been conducted at SPring-8 Angstrom Compact free-electron LAser (SACLA) using the custom-made diffraction apparatus KOTOBUKI-1 and two multiport CCD detectors. In the experiments, ten thousands of single-shot diffraction patterns can be collected within several hours. Then, diffraction patterns with significant levels of intensity suitable for structural analysis must be found, direct-beam positions in diffraction patterns determined, diffraction patterns from the two CCD detectors merged, and phase-retrieval calculations for structural analyses performed. A software suite named SITENNO has been developed to semi-automatically apply the four-step processing to a huge number of diffraction data. Here, details of the algorithm used in the suite are described and the performance for approximately 9000 diffraction patterns collected from cuboid-shaped copper oxide particles reported. Using the SITENNO suite, it is possible to conduct experiments with data processing immediately after the data collection, and to characterize the size distribution and internal structures of the non-crystalline particles

  12. Multiple nonlinear Bragg diffraction of femtosecond laser pulses in a {\\chi^{(2)}} photonic lattice with hexagonal domains

    Science.gov (United States)

    Vyunishev, A. M.; Arkhipkin, V. G.; Baturin, I. S.; Akhmatkhanov, A. R.; Shur, V. Ya; Chirkin, A. S.

    2018-04-01

    The frequency doubling of femtosecond laser pulses in a two-dimensional (2D) rectangular nonlinear photonic lattice with hexagonal domains is studied experimentally and theoretically. The broad fundamental spectrum enables frequency conversion under nonlinear Bragg diffraction for a series of transverse orders at a fixed longitudinal quasi-phase-matching order. The consistent nonstationary theory of the frequency doubling of femtosecond laser pulses is developed using the representation based on the reciprocal lattice of the structure. The calculated spatial distribution of the second-harmonic spectral intensity agrees well with the experimental data. The condition for multiple nonlinear Bragg diffraction in a 2D nonlinear photonic lattice is offered. The hexagonal shape of the domains contributes to multibeam second harmonic excitation. The maximum conversion efficiency for a series of transverse orders in the range 0.01%-0.03% is obtained.

  13. ARGOS laser system mechanical design

    Science.gov (United States)

    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.

  14. Development of automatic laser welding system

    International Nuclear Information System (INIS)

    Ohwaki, Katsura

    2002-01-01

    Laser are a new production tool for high speed and low distortion welding and applications to automatic welding lines are increasing. IHI has long experience of laser processing for the preservation of nuclear power plants, welding of airplane engines and so on. Moreover, YAG laser oscillators and various kinds of hardware have been developed for laser welding and automation. Combining these welding technologies and laser hardware technologies produce the automatic laser welding system. In this paper, the component technologies are described, including combined optics intended to improve welding stability, laser oscillators, monitoring system, seam tracking system and so on. (author)

  15. Some characteristics of isotopic separation laser systems

    International Nuclear Information System (INIS)

    Pochon, E.

    1988-01-01

    The principle of Laser Isotope Separation (LIS) is simple and based on either selective electronic photoexcitation and photoionization of atomic vapor, or selective vibrational photoexcitation and photodissociation of molecules in the gas phase. These processes, respectively called SILVA (AVLIS) and SILMO (MLIS) in France, both use specific laser systems with wavelengths spanning from infrared to ultraviolet. This article describes briefly some of the characteristics of a SILVA laser system. Following a three-step process, a SILVA laser system is based on dye copper vapor lasers. The pulse dye lasers provide the tunable laser light and are optically pumped by copper vapor laser operating at high repetition rates. In order to meet plant laser system requirements, the main improvements under way relate to copper vapor laser devices the power capability, efficiency, reliability and lifetime of which have to be increased. 1 fig

  16. Stray light characteristics of the diffractive telescope system

    Science.gov (United States)

    Liu, Dun; Wang, Lihua; Yang, Wei; Wu, Shibin; Fan, Bin; Wu, Fan

    2018-02-01

    Diffractive telescope technology is an innovation solution in construction of large light-weight space telescope. However, the nondesign orders of diffractive optical elements (DOEs) may affect the imaging performance as stray light. To study the stray light characteristics of a diffractive telescope, a prototype was developed and its stray light analysis model was established. The stray light characteristics including ghost, point source transmittance, and veiling glare index (VGI) were analyzed. During the star imaging test of the prototype, the ghost images appeared around the star image as the exposure time of the charge-coupled device improving, consistent with the simulation results. The test result of VGI was 67.11%, slightly higher than the calculated value 57.88%. The study shows that the same order diffraction of the diffractive primary lens and correcting DOE is the main factor that causes ghost images. The stray light sources outside the field of view can illuminate the image plane through nondesign orders diffraction of the primary lens and contributes to more than 90% of the stray light flux on the image plane. In summary, it is expected that these works will provide some guidance for optimizing the imaging performance of diffractive telescopes.

  17. Applications of the lots computer code to laser fusion systems and other physical optics problems

    International Nuclear Information System (INIS)

    Lawrence, G.; Wolfe, P.N.

    1979-01-01

    The Laser Optical Train Simulation (LOTS) code has been developed at the Optical Sciences Center, University of Arizona under contract to Los Alamos Scientific Laboratory (LASL). LOTS is a diffraction based code designed to beam quality and energy of the laser fusion system in an end-to-end calculation

  18. Laser-based agriculture system

    KAUST Repository

    Ooi, Boon S.

    2016-03-31

    A system and method are provided for indoor agriculture using at least one growth chamber illuminated by laser light. In an example embodiment of the agriculture system, a growth chamber is provided having one or more walls defining an interior portion of the growth chamber. The agriculture system may include a removable tray disposed within the interior portion of the growth chamber. The agriculture system also includes a light source, which may be disposed outside the growth chamber. The one or more walls may include at least one aperture. The light source is configured to illuminate at least a part of the interior portion of the growth chamber. In embodiments in which the light source is disposed outside the growth chamber, the light source is configured to transmit the laser light to the interior portion of the growth chamber via the at least one aperture.

  19. Laser-based agriculture system

    KAUST Repository

    Ooi, Boon S.; Wong, Aloysius Tze; Ng, Tien Khee

    2016-01-01

    A system and method are provided for indoor agriculture using at least one growth chamber illuminated by laser light. In an example embodiment of the agriculture system, a growth chamber is provided having one or more walls defining an interior portion of the growth chamber. The agriculture system may include a removable tray disposed within the interior portion of the growth chamber. The agriculture system also includes a light source, which may be disposed outside the growth chamber. The one or more walls may include at least one aperture. The light source is configured to illuminate at least a part of the interior portion of the growth chamber. In embodiments in which the light source is disposed outside the growth chamber, the light source is configured to transmit the laser light to the interior portion of the growth chamber via the at least one aperture.

  20. An instrument for in situ time-resolved X-ray imaging and diffraction of laser powder bed fusion additive manufacturing processes

    Science.gov (United States)

    Calta, Nicholas P.; Wang, Jenny; Kiss, Andrew M.; Martin, Aiden A.; Depond, Philip J.; Guss, Gabriel M.; Thampy, Vivek; Fong, Anthony Y.; Weker, Johanna Nelson; Stone, Kevin H.; Tassone, Christopher J.; Kramer, Matthew J.; Toney, Michael F.; Van Buuren, Anthony; Matthews, Manyalibo J.

    2018-05-01

    In situ X-ray-based measurements of the laser powder bed fusion (LPBF) additive manufacturing process produce unique data for model validation and improved process understanding. Synchrotron X-ray imaging and diffraction provide high resolution, bulk sensitive information with sufficient sampling rates to probe melt pool dynamics as well as phase and microstructure evolution. Here, we describe a laboratory-scale LPBF test bed designed to accommodate diffraction and imaging experiments at a synchrotron X-ray source during LPBF operation. We also present experimental results using Ti-6Al-4V, a widely used aerospace alloy, as a model system. Both imaging and diffraction experiments were carried out at the Stanford Synchrotron Radiation Lightsource. Melt pool dynamics were imaged at frame rates up to 4 kHz with a ˜1.1 μm effective pixel size and revealed the formation of keyhole pores along the melt track due to vapor recoil forces. Diffraction experiments at sampling rates of 1 kHz captured phase evolution and lattice contraction during the rapid cooling present in LPBF within a ˜50 × 100 μm area. We also discuss the utility of these measurements for model validation and process improvement.

  1. Method and system for homogenizing diode laser pump arrays

    Science.gov (United States)

    Bayramian, Andy J

    2013-10-01

    An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance. A second intensity profile measured at the input face of the amplifier slab as a function of the first direction has a variation less than 10%.

  2. Novel design and sensitivity analysis of displacement measurement system utilizing knife edge diffraction for nanopositioning stages.

    Science.gov (United States)

    Lee, ChaBum; Lee, Sun-Kyu; Tarbutton, Joshua A

    2014-09-01

    This paper presents a novel design and sensitivity analysis of a knife edge-based optical displacement sensor that can be embedded with nanopositioning stages. The measurement system consists of a laser, two knife edge locations, two photodetectors, and axillary optics components in a simple configuration. The knife edge is installed on the stage parallel to its moving direction and two separated laser beams are incident on knife edges. While the stage is in motion, the direct transverse and diffracted light at each knife edge is superposed producing interference at the detector. The interference is measured with two photodetectors in a differential amplification configuration. The performance of the proposed sensor was mathematically modeled, and the effect of the optical and mechanical parameters, wavelength, beam diameter, distances from laser to knife edge to photodetector, and knife edge topography, on sensor outputs was investigated to obtain a novel analytical method to predict linearity and sensitivity. From the model, all parameters except for the beam diameter have a significant influence on measurement range and sensitivity of the proposed sensing system. To validate the model, two types of knife edges with different edge topography were used for the experiment. By utilizing a shorter wavelength, smaller sensor distance and higher edge quality increased measurement sensitivity can be obtained. The model was experimentally validated and the results showed a good agreement with the theoretically estimated results. This sensor is expected to be easily implemented into nanopositioning stage applications at a low cost and mathematical model introduced here can be used for design and performance estimation of the knife edge-based sensor as a tool.

  3. Laser systems for on-line laser ion sources

    International Nuclear Information System (INIS)

    Geppert, Christopher

    2008-01-01

    Since its initiation in the middle of the 1980s, the resonant ionization laser ion source has been established as a reliable and efficient on-line ion source for radioactive ion beams. In comparison to other on-line ion sources it comprises the advantages of high versatility for the elements to be ionized and of high selectivity and purity for the ion beam generated by resonant laser radiation. Dye laser systems have been the predominant and pioneering working horses for laser ion source applications up to recently, but the development of all-solid-state titanium:sapphire laser systems has nowadays initiated a significant evolution within this field. In this paper an overview of the ongoing developments will be given, which have contributed to the establishment of a number of new laser ion source facilities worldwide during the last five years.

  4. High speed laser tomography system

    Science.gov (United States)

    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 120000slices/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.

  5. Near-diffraction-limited segmented broad area diode laser based on off-axis spectral beam combining

    DEFF Research Database (Denmark)

    Jensen, O.B.; Thestrup Nielsen, Birgitte; Andersen, Peter E.

    2006-01-01

    -feedback scheme we are able to improve the beam quality of the laser by a factor of 23 from M-2 = 55 for the free-running diode laser to M-2 = 2.4 for the laser with feedback at a drive current of 2.2 A. The improved M-2 value is a factor of 3.4 below M-2 = 8.2 for a single free-running segment. This is the first......The beam quality of a 500-mu m-wide broad area diode laser with five active segments has been improved beyond the beam quality of the individual segments. The principle of this new laser system is based on off-axis feedback in combination with spectral beam combining. By using a double...... time that the beam quality of a segmented broad area diode laser has been improved beyond the beam quality of the individual segments....

  6. Navigated Pattern Laser System versus Single-Spot Laser System for Postoperative 360-Degree Laser Retinopexy.

    Science.gov (United States)

    Kulikov, Alexei N; Maltsev, Dmitrii S; Boiko, Ernest V

    2016-01-01

    Purpose . To compare three 360°-laser retinopexy (LRP) approaches (using navigated pattern laser system, single-spot slit-lamp (SL) laser delivery, and single-spot indirect ophthalmoscope (IO) laser delivery) in regard to procedure duration, procedural pain score, technical difficulties, and the ability to achieve surgical goals. Material and Methods . Eighty-six rhegmatogenous retinal detachment patients (86 eyes) were included in this prospective randomized study. The mean procedural time, procedural pain score (using 4-point Verbal Rating Scale), number of laser burns, and achievement of the surgical goals were compared between three groups (pattern LRP (Navilas® laser system), 36 patients; SL-LRP, 28 patients; and IO-LRP, 22 patients). Results . In the pattern LRP group, the amount of time needed for LRP and pain level were statistically significantly lower, whereas the number of applied laser burns was higher compared to those in the SL-LRP group and in the IO-LRP group. In the pattern LRP, SL-LRP, and IO-LRP groups, surgical goals were fully achieved in 28 (77.8%), 17 (60.7%), and 13 patients (59.1%), respectively ( p > 0.05). Conclusion . The navigated pattern approach allows improving the treatment time and pain in postoperative 360° LRP. Moreover, 360° pattern LRP is at least as effective in achieving the surgical goal as the conventional (slit-lamp or indirect ophthalmoscope) approaches with a single-spot laser.

  7. X-diffraction technique applied for nano system metrology

    International Nuclear Information System (INIS)

    Kuznetsov, Alexei Yu.; Machado, Rogerio; Robertis, Eveline de; Campos, Andrea P.C.; Archanjo, Braulio S.; Gomes, Lincoln S.; Achete, Carlos A.

    2009-01-01

    The application of nano materials are fast growing in all industrial sectors, with a strong necessity in nano metrology and normalizing in the nano material area. The great potential of the X-ray diffraction technique in this field is illustrated at the example of metals, metal oxides and pharmaceuticals

  8. Improvements of the ruby laser oscillator system for laser scattering

    International Nuclear Information System (INIS)

    Yamauchi, Toshihiko; Kumagai, Katsuaki; Kawakami, Tomohide; Matoba, Tohru; Funahashi, Akimasa

    1978-10-01

    A ruby laser oscillator system is used to measure electron temperatures of the Tokamak plasmas(JFT-2 and JFT-2a). Improvements have been made of the laser oscillator to obtain the correct values. Described are the improvements and the damages of a ruby rod and a KD*P crystal for Q-switching by laser beam. Improvement are the linear Xe lamp replaced by a helical Xe lamp and in the electrical circuit for Q-switching. The damage of an optical component by a laser beam should be clarified from the damage data; the cause is not found yet. (author)

  9. Single-particle coherent diffractive imaging with a soft x-ray free electron laser: towards soot aerosol morphology

    Science.gov (United States)

    Bogan, Michael J.; Starodub, Dmitri; Hampton, Christina Y.; Sierra, Raymond G.

    2010-10-01

    The first of its kind, the Free electron LASer facility in Hamburg, FLASH, produces soft x-ray pulses with unprecedented properties (10 fs, 6.8-47 nm, 1012 photons per pulse, 20 µm diameter). One of the seminal FLASH experiments is single-pulse coherent x-ray diffractive imaging (CXDI). CXDI utilizes the ultrafast and ultrabright pulses to overcome resolution limitations in x-ray microscopy imposed by x-ray-induced damage to the sample by 'diffracting before destroying' the sample on sub-picosecond timescales. For many lensless imaging algorithms used for CXDI it is convenient when the data satisfy an oversampling constraint that requires the sample to be an isolated object, i.e. an individual 'free-standing' portion of disordered matter delivered to the centre of the x-ray focus. By definition, this type of matter is an aerosol. This paper will describe the role of aerosol science methodologies used for the validation of the 'diffract before destroy' hypothesis and the execution of the first single-particle CXDI experiments being developed for biological imaging. FLASH CXDI now enables the highest resolution imaging of single micron-sized or smaller airborne particulate matter to date while preserving the native substrate-free state of the aerosol. Electron microscopy offers higher resolution for single-particle analysis but the aerosol must be captured on a substrate, potentially modifying the particle morphology. Thus, FLASH is poised to contribute significant advancements in our knowledge of aerosol morphology and dynamics. As an example, we simulate CXDI of combustion particle (soot) morphology and introduce the concept of extracting radius of gyration of fractal aggregates from single-pulse x-ray diffraction data. Future upgrades to FLASH will enable higher spatially and temporally resolved single-particle aerosol dynamics studies, filling a critical technological need in aerosol science and nanotechnology. Many of the methodologies described for FLASH will

  10. Short-time X-ray diffraction with an efficient-optimized, high repetition-rate laser-plasma X-ray-source

    International Nuclear Information System (INIS)

    Kaehle, Stephan

    2009-01-01

    This thesis deals with the production and application of ultrashort X-ray pulses. In the beginning different possibilities for the production of X-ray pulses with pulse durations of below one picosecond are presented, whereby the main topic lies on the so called laser-plasma X-ray sources with high repetition rate. In this case ultrashort laser pulses are focused on a metal, so that in the focus intensities of above 10 16 W/cm 2 dominate. In the ideal case in such way ultrafast electrons are produced, which are responsible for line radiation. In these experiments titanium K α radiation is produced, thes photons possess an energy of 4.51 keV. For the efficient production of line radiation here the Ti:Sa laser is optimized in view of the laser energy and the pulse shape and the influence of the different parameters on the K α production systematically studied. The influences of laser intensity, system-conditioned pre-pulses and of phase modulation are checked. It turns out that beside the increasement of the K α radiation by a suited laser intensity a reduction of the X-ray background radiation is of deciding importance for the obtaining of clear diffraction images. This background radiation is mainly composed of bremsstrahlung. It can be suppressed by the avoidance of intrinsic pre-pulses and by means of 2nd-order phase modulation. By means of optical excitation and X-ray exploration experiments the production of acoustic waves after ultrashort optical excitation in a 150 nm thick Ge(111) film on Si(111) is studied. These acoustic waves are driven by thermal (in this time scale time-independent) and electronic (time dependent) pressure amounts. As essential results it turns out that the relative amount of the electronic pressure increases with decreasing excitation density [de

  11. 3.5 W of diffraction-limited green light at 515 nm from SHG of a single-frequency tapered diode laser

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin; Hansen, Anders Kragh; Müller, André

    2017-01-01

    Multi-Watt efficient compact green laser sources are required for a number of applications e.g. within biophotonics, laser pumping and laser displays. We present generation of 3.5 W of diffraction-limited green light at 515 nm by second harmonic generation (SHG) of a tapered diode laser, itself...... yielding more than 9 W at 1030 nm. SHG is performed in single pass through a cascade of two nonlinear crystals with re-focusing and dispersion compensating optics between the two nonlinear crystals. The laser is single-frequency and the output power is stabilized to better than ±0.4%....

  12. Coherent phonon excitation and linear thermal expansion in structural dynamics and ultrafast electron diffraction of laser-heated metals.

    Science.gov (United States)

    Tang, Jau

    2008-04-28

    In this study, we examine the ultrafast structural dynamics of metals induced by a femtosecond laser-heating pulse as probed by time-resolved electron diffraction. Using the two-temperature model and the Grüneisen relationship we calculate the electron temperature, phonon temperature, and impulsive force at each atomic site in the slab. Together with the Fermi-Pasta-Ulam anharmonic chain model we calculate changes of bond distance and the peak shift of Bragg spots or Laue rings. A laser-heated thin slab is shown to exhibit "breathing" standing-wave behavior, with a period equal to the round-trip time for sound wave and a wavelength twice the slab thickness. The peak delay time first increases linearly with the thickness (linear thermal expansion due to lattice temperature jump are shown to contribute to the overall structural changes. Differences between these two mechanisms and their dependence on film thickness and other factors are discussed.

  13. ADVANTAGES OF DIFFRACTIVE OPTICAL ELEMENTS APPLICATION IN SIMPLE OPTICAL IMAGING SYSTEMS

    Directory of Open Access Journals (Sweden)

    N. D. Zoric

    2015-01-01

    Full Text Available The paper deals with the influence of diffractive optical elements on the optical aberrations. The correction of optical aberrations was investigated in the simple optical systems with one and two lenses (singlet and doublet. The advantages of diffractive optical elements are their ability to generate arbitrary complex wave fronts from a piece of optical material that is essentially flat. The optical systems consisting of the standard surfaces were designed and optimized by using the same starting points. Further, the diffractive and aspheric surfaces were introduced into the developed systems. The resulting hybrid systems were optimized. To compare the complicity of the development of narrow field systems and wide field optical systems, the optimization has been done separately for these two types of the instruments. The optical systems were designed by using special Optical Design Software. Тhe characteristics of designed diffractive surfaces were controlled in Software DIFSYS 2.30. Due to the application of diffractive optical elements the longitudinal chromatic aberration was 5 times reduced for the narrow field systems. The absolute value of Seidel coefficient related to the spherical aberration was reduced in the range of 0.03. Considering that diffractive optical elements have the known disadvantages, like possible parasitic diffraction orders and probable decrease of the transmission, we also developed and analyzed the optical systems with combined aspheric and diffractive surfaces. A combination of the aspheric and diffractive surfaces in the optical disk system of the disk reading lens, gave cutting down of the longitudinal color aberrations almost 15 times on-axis, comparing to the lens consisting of the aspherical and standard surfaces. All of the designed diffractive optical elements possess the parameters within the fabrication limits.

  14. CO laser angioplasty system: efficacy of manipulatable laser angioscope catheter

    Science.gov (United States)

    Arai, Tsunenori; Kikuchi, Makoto; Mizuno, Kyoichi; Sakurada, Masami; Miyamoto, Akira; Arakawa, Koh; Kurita, Akira; Nakamura, Haruo; Takeuchi, Kiyoshi; Utsumi, Atsushi; Akai, Yoshiro

    1992-08-01

    A percutaneous transluminal coronary angioplasty system using a unique combination of CO laser (5 micrometers ) and As-S infrared glass fiber under the guidance of a manipulatable laser angioscope catheter is described. The ablation and guidance functions of this system are evaluated. The angioplasty treatment procedure under angioscope guidance was studied by in vitro model experiment and in vivo animal experiment. The whole angioplasty system is newly developed. That is, a transportable compact medical CO laser device which can emit up to 10 W, a 5 F manipulatable laser angioscope catheter, a thin CO laser cable of which the diameter is 0.6 mm, an angioscope imaging system for laser ablation guidance, and a system controller were developed. Anesthetized adult mongrel dogs (n equals 5) with an artificial complete occlusion in the femoral artery and an artificial human vessel model including occluded or stenotic coronary artery were used. The manipulatability of the catheter was drastically improved (both rotation and bending), therefore, precise control of ablation to expand stenosis was obtained. A 90% artificial stenosis made of human yellow plaque in 4.0 mm diameter in the vessel was expanded to 70% stenosis by repetitive CO laser ablations of which total energy was 220 J. All procedures were performed and controlled under angioscope visualization.

  15. The trickle before the torrent-diffraction data from X-ray lasers.

    Science.gov (United States)

    Maia, Filipe R N C; Hajdu, Janos

    2016-08-01

    Today Scientific Data launched a collection of publications describing data from X-ray free-electron lasers under the theme 'Structural Biology Applications of X-ray Lasers'. The papers cover data on nanocrystals, single virus particles, isolated cell organelles, and living cells. All data are deposited with the Coherent X-ray Imaging Data Bank (CXIDB) and available to the scientific community to develop ideas, tools and procedures to meet challenges with the expected torrents of data from new X-ray lasers, capable of producing billion exposures per day.

  16. Modeling laser beam diffraction and propagation by the mode-expansion method.

    Science.gov (United States)

    Snyder, James J

    2007-08-01

    In the mode-expansion method for modeling propagation of a diffracted beam, the beam at the aperture can be expanded as a weighted set of orthogonal modes. The parameters of the expansion modes are chosen to maximize the weighting coefficient of the lowest-order mode. As the beam propagates, its field distribution can be reconstructed from the set of weighting coefficients and the Gouy phase of the lowest-order mode. We have developed a simple procedure to implement the mode-expansion method for propagation through an arbitrary ABCD matrix, and we have demonstrated that it is accurate in comparison with direct calculations of diffraction integrals and much faster.

  17. Camera for coherent diffractive imaging and holography with a soft-x-ray free-electron laser

    International Nuclear Information System (INIS)

    Bajt, Sasa; Chapman, Henry N.; Spiller, Eberhard A.; Alameda, Jennifer B.; Woods, Bruce W.; Frank, Matthias; Bogan, Michael J.; Barty, Anton; Boutet, Sebastien; Marchesini, Stefano; Hau-Riege, Stefan P.; Hajdu, Janos; Shapiro, David

    2008-01-01

    We describe a camera to record coherent scattering patterns with a soft-x-ray free-electron laser (FEL). The camera consists of a laterally graded multilayer mirror, which reflects the diffraction pattern onto a CCD detector. The mirror acts as a bandpass filter for both the wavelength and the angle, which isolates the desired scattering pattern from nonsample scattering or incoherent emission from the sample. The mirror also solves the particular problem of the extreme intensity of the FEL pulses, which are focused to greater than 10 14 W/cm 2 . The strong undiffracted pulse passes through a hole in the mirror and propagates onto a beam dump at a distance behind the instrument rather than interacting with a beam stop placed near the CCD. The camera concept is extendable for the full range of the fundamental wavelength of the free electron laser in Hamburg (FLASH) FEL (i.e., between 6 and 60 nm) and into the water window. We have fabricated and tested various multilayer mirrors for wavelengths of 32, 16, 13.5, and 4.5 nm. At the shorter wavelengths mirror roughness must be minimized to reduce scattering from the mirror. We have recorded over 30,000 diffraction patterns at the FLASH FEL with no observable mirror damage or degradation of performance

  18. Laser spark distribution and ignition system

    Science.gov (United States)

    Woodruff, Steven [Morgantown, WV; McIntyre, Dustin L [Morgantown, WV

    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.

  19. Fission fragment excited laser system

    Science.gov (United States)

    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.

  20. Short pulse laser systems for biomedical applications

    CERN Document Server

    Mitra, Kunal

    2017-01-01

    This book presents practical information on the clinical applications of short pulse laser systems and the techniques for optimizing these applications in a manner that will be relevant to a broad audience, including engineering and medical students as well as researchers, clinicians, and technicians. Short pulse laser systems are useful for both subsurface tissue imaging and laser induced thermal therapy (LITT), which hold great promise in cancer diagnostics and treatment. Such laser systems may be used alone or in combination with optically active nanoparticles specifically administered to the tissues of interest for enhanced contrast in imaging and precise heating during LITT. Mathematical and computational models of short pulse laser-tissue interactions that consider the transient radiative transport equation coupled with a bio-heat equation considering the initial transients of laser heating were developed to analyze the laser-tissue interaction during imaging and therapy. Experiments were first performe...

  1. Laser and photonic systems design and integration

    CERN Document Server

    Nof, Shimon Y; Cheng, Gary J

    2014-01-01

    New, significant scientific discoveries in laser and photonic technologies, systems perspectives, and integrated design approaches can improve even further the impact in critical areas of challenge. Yet this knowledge is dispersed across several disciplines and research arenas. Laser and Photonic Systems: Design and Integration brings together a multidisciplinary group of experts to increase understanding of the ways in which systems perspectives may influence laser and photonic innovations and application integration.By bringing together chapters from leading scientists and technologists, ind

  2. Multiplex electric discharge gas laser system

    Science.gov (United States)

    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.

  3. Materials for spaceborne laser systems

    International Nuclear Information System (INIS)

    Gusarov, A.

    2006-01-01

    Advanced laser systems are attracting a growing interest for space missions, in particular for LIDAR (LIght Detection And Ranging) applications. An important issue for the LIDARs is the very strict requirements on the optical performance and more specifically the need for a high optical output power combined with a nearly perfect output beam quality. These features are traditionally in conflict with each other. Thermally induced phase distortions indeed corrupt the beam quality of high-power solid-state lasers and it becomes increasingly difficult to maintain a good beam quality while increasing the output power. A possible solution of the problem is to use the optical phase conjugation, which provides a method to dynamically correct for those aberrations. A process by which phase-conjugated waves can be generated is the SBS (stimulated Brillouin scattering). SBS mirrors commonly used in terrestrial application are based on liquids or gases, which are not 'space-friendly' and often toxic. The solid-state alternative seems the most appropriate for space. Such PCMs (Phase-Conjugating Mirrors) have been the subject of many research efforts in recent years and a significant progress in improving their characteristics has been achieved. However, the issue of space qualification remains open. To address it, the European Space Agency initiated in 2004 the research project named Solid-State Phase Conjugation, Radiation Testing and Evaluation for Core Laser Technologies with the TRT (Thales Research and Technology), France, as the prime contractor, and the CSL (Centre Spatial de Liege) and SCKCEN as the subcontractors. The project is to be completed in 2006. To qualify a PCM for a spaceborne laser system, one has to address a number of specific issues. Such a component must be mechanically rugged to sustain vibrations during the launch phase, provide a low out-gassing to prevent optical surfaces contamination in vacuum, be highly reliable to operate properly without

  4. FELIX: an algorithm for indexing multiple crystallites in X-ray free-electron laser snapshot diffraction images

    DEFF Research Database (Denmark)

    Beyerlein, Kenneth R.; White, Thomas A.; Yefanov, Oleksandr

    2017-01-01

    A novel algorithm for indexing multiple crystals in snapshot X-ray diffraction images, especially suited for serial crystallography data, is presented. The algorithm, FELIX, utilizes a generalized parametrization of the Rodrigues-Frank space, in which all crystal systems can be represented without...

  5. Dynamically variable spot size laser system

    Science.gov (United States)

    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. Generation of 3.5 W of diffraction-limited green light from SHG of a single tapered diode laser in a cascade of nonlinear crystals

    DEFF Research Database (Denmark)

    Hansen, Anders Kragh; Jensen, Ole Bjarlin; Sumpf, Bernd

    2014-01-01

    Many applications, e.g., within biomedicine stand to benefit greatly from the development of diode laser-based multi- Watt efficient compact green laser sources. The low power of existing diode lasers in the green area (about 100 mW) means that the most promising approach remains nonlinear...... frequency conversion of infrared tapered diode lasers. Here, we describe the generation of 3.5 W of diffraction-limited green light from SHG of a single tapered diode laser, itself yielding 10 W at 1063 nm. This SHG is performed in single pass through a cascade of two PPMgO:LN crystals with re...... power of 3.5 W corresponds to a power enhancement greater than 2 compared to SHG in each of the crystals individually and is the highest visible output power generated by frequency conversion of a single diode laser. Such laser sources provide the necessary pump power for biophotonics applications...

  7. Evaluation between residual stresses obtained by neutron diffraction and simulation for dual phase steel welded by laser process

    Science.gov (United States)

    Kouadri-Henni, Afia; Malard, Benoit

    2018-05-01

    This study aimed at characterizing the residual stresses (RS) distribution of a Dual Phase Steel (DP600) undergoing a Laser Beam Welding (LBW) with two different laser parameters. The RS in the ferritic phase have been experimentally determined by the use of the neutrons diffraction technique. The results confirmed a gradient of RS among different zones both on the top and below surfaces but also through the thickness of the fusion zone. Low compressive stresses were observed in the Base Metal (BM) close to the Heat Affected Zone (HAZ) whereas high tensile stresses were observed in the Fusion Zone (FZ). Numerical results showed a difference in the RS distribution depending on the model used. In the end, it appears that the high temperature gradient, specific to the laser beam, is the main factor governing the RS. Our results suggest as well that the approach regarding the RS should consider not only the temperature but also process parameters. When comparing simulation results with experimental data, the values converge well in some zones, in particular the FZ and the others less.

  8. Theory and Application of Photoelectron Diffraction for Complex Oxide Systems

    Science.gov (United States)

    Chassé, Angelika; Chassé, Thomas

    2018-06-01

    X-ray photoelectron diffraction (XPD) has been used to investigate film structures and local sites of surface and dopant atoms in complex oxide materials. We have performed angular-resolved measurements of intensity distribution curves (ADCs) and patterns (ADPs) of elemental core level intensities from binary to quaternary mixed oxide samples and compared them to multiple-scattering cluster (MSC) calculations in order to derive information on structural models and related parameters. MSC calculations permitted to describe both bulk diffraction features of binary oxide MnO(001) and the thickness-dependence of the tetragonal distortion of epitaxial MnO films on Ag(001). XPD was further used to investigate the surface termination of perovskite SrTiO3 and BaTiO3 substrates in order to evaluate influence of different ex situ and in situ preparation procedures on the surface layers, which are crucial for quality of following film growth. Despite the similarity of local environments of Sr (Ba) and Ti atoms in the perovskite film structure an angular region in the ADCs was identified as a fingerprint with the help of MSC simulations which provided clear conclusions on the perovskite oxide surfaces. Dopant sites in quaternary perovskite manganites La1-xCaxMnO3, La1-xSrxMnO3, and La1-xCexMnO3 were studied with polar angle scans of the photoemission intensities of host and dopant atoms. Both direct comparison of experimental ADCs and to the simulations within MSC models confirm the occupation of A sites by the dopants and the structural quality of the complex oxide films.

  9. National Ignition Facility system design requirements Laser System SDR002

    International Nuclear Information System (INIS)

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

    1996-01-01

    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

  10. Particle size distribution in soils and marine sediments by laser diffraction using Malvern Mastersizer 2000—method uncertainty including the effect of hydrogen peroxide pretreatment

    DEFF Research Database (Denmark)

    Callesen, Ingeborg; Keck, Hannes; Andersen, Thorbjørn Joest

    2018-01-01

    with less than 1% C and some marine sediments. Materials and methods: The method uncertainty for particle size analysis by the laser diffraction method using or not using H2O2 pretreatment followed by 2 min ultrasound and 1-mm sieving was determined for two soil samples and two aquatic sediments......Purpose: Methods for particle size distribution (PSD) determination by laser diffraction are not standardized and differ between disciplines and sectors. The effect of H2O2 pretreatment before a sonication treatment in laser diffraction analysis of soils and marine sediments was examined on soils...... pretreatment on the PSD was small and not significant. The standard deviation (std) in particle size fractions increased with particle size. PSDs and std for some samples were presented for future reference. Similar to other studies, the content of clay and silt (by sieving/hydrometer, SHM) was lower...

  11. Laser Setup for Volume Diffractive Optical Elements Recording in Photo-Thermo-Refractive Glass

    Science.gov (United States)

    2016-04-14

    Total Number: PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: PERCENT_SUPPORTEDNAME FTE Equivalent: Total Number: Sub Contractors (DD882) Names of...3 1b 2 3 a b Fig. 14. Schematic of a DBR (a) and DFB (b) lasers in Yb doped PTR glass. 1a and 1b – dichroic beam splitters with HR at 1066 nm and HT

  12. Self-reconstruction of diffraction-free and accelerating laser beams in scattering media

    International Nuclear Information System (INIS)

    Ersoy, T.; Yalizay, B.; Akturk, S.

    2012-01-01

    We experimentally investigate propagation of laser beams with different intensity profiles in highly scattering media. We generate transverse laser amplitude profiles with Gaussian, Bessel and Airy function envelopes. We then propagate these beams through optical phantoms formed with variable density intralipid solutions. At the sample exit, we compare change in maximum intensities, as well as beam profile reconstruction. We show that self-reconstruction properties of Bessel and Airy beams bring about slower decrease in maximum intensity with increasing scatterer density. On the other hand, the beam profiles deteriorate faster, as compared to reference Gaussian beams. Slower decrease in the intensity can be attributed to the wavevector spectra providing a continuous flow of energy to the beam center, while beam deterioration is linked to total beam volume in the scattering medium. These results show that beam shaping methods can significantly enhance delivery of intense light deeper into turbid media, but this enhancement is compromised by stronger speckling of beam profiles. -- Highlights: ► We experimentally investigate propagation of shaped laser beams in turbid media. ► Peak intensity of Bessel and Airy beams decrease slower with increasing scatterer. ► Shaped beam profiles deteriorate faster, as compared to reference Gaussian beams. ► Shaped beam profiles can enhance applications of lasers inscattering media.

  13. Single-particle coherent diffractive imaging with a soft x-ray free electron laser: towards soot aerosol morphology

    International Nuclear Information System (INIS)

    Bogan, Michael J; Starodub, Dmitri; Hampton, Christina Y; Sierra, Raymond G

    2010-01-01

    The first of its kind, the Free electron LASer facility in Hamburg, FLASH, produces soft x-ray pulses with unprecedented properties (10 fs, 6.8-47 nm, 10 12 photons per pulse, 20 μm diameter). One of the seminal FLASH experiments is single-pulse coherent x-ray diffractive imaging (CXDI). CXDI utilizes the ultrafast and ultrabright pulses to overcome resolution limitations in x-ray microscopy imposed by x-ray-induced damage to the sample by 'diffracting before destroying' the sample on sub-picosecond timescales. For many lensless imaging algorithms used for CXDI it is convenient when the data satisfy an oversampling constraint that requires the sample to be an isolated object, i.e. an individual 'free-standing' portion of disordered matter delivered to the centre of the x-ray focus. By definition, this type of matter is an aerosol. This paper will describe the role of aerosol science methodologies used for the validation of the 'diffract before destroy' hypothesis and the execution of the first single-particle CXDI experiments being developed for biological imaging. FLASH CXDI now enables the highest resolution imaging of single micron-sized or smaller airborne particulate matter to date while preserving the native substrate-free state of the aerosol. Electron microscopy offers higher resolution for single-particle analysis but the aerosol must be captured on a substrate, potentially modifying the particle morphology. Thus, FLASH is poised to contribute significant advancements in our knowledge of aerosol morphology and dynamics. As an example, we simulate CXDI of combustion particle (soot) morphology and introduce the concept of extracting radius of gyration of fractal aggregates from single-pulse x-ray diffraction data. Future upgrades to FLASH will enable higher spatially and temporally resolved single-particle aerosol dynamics studies, filling a critical technological need in aerosol science and nanotechnology. Many of the methodologies described for FLASH will

  14. Design of single-longitudinal-mode laser oscillator for edge Thomson scattering system in ITER

    International Nuclear Information System (INIS)

    Hatae, Takaki; Kusama, Yoshinori; Kubomura, Hiroyuki; Matsuoka, Shin-ichi

    2006-06-01

    A high output energy (5J) and high repetition rate (100 Hz) laser system is required for the edge Thomson scattering system in ITER. A YAG laser (Nd:YAG laser) is a first candidate for the laser system satisfying the requirements. It is important to develop a high beam quality and single longitudinal mode (SLM) laser oscillator in order to realize this high power laser system. In this design work, following activities relating to the SLM laser oscillator have been carried out: design of the laser head and the resonator, estimation of the output power for the SLM laser oscillator, consideration of the feedback control scheme and consideration of interface for amplification system to achieve required performance (5J, 100 Hz). It is expected that the designed laser diode (LD) pumped SLM laser oscillator realizes: 100 Hz of repetition rate, 10 mJ of output energy, 10 ns of pulse width, single longitudinal mode, TEM 00 of transversal mode, divergence less than 4 times of the diffraction limit, energy stability within 5%. (author)

  15. Diffracted X-ray tracking: new system for single molecular detection with X-rays

    CERN Document Server

    Sasaki, Y C; Adachi, S; Suzuki, Y; Yagi, N

    2001-01-01

    We propose a new X-ray methodology for direct observations of the behaviors of single molecular units in real time and real space. This new system, which we call Diffracted X-ray Tracking (DXT), monitors the Brownian motions of a single molecular unit by observations of X-ray diffracted spots from a nanocrystal, tightly bound to the individual single molecular unit in bio-systems. DXT does not determine any translational movements, but only orientational movements.

  16. Diffracted X-ray tracking: new system for single molecular detection with X-rays

    International Nuclear Information System (INIS)

    Sasaki, Y.C.; Okumura, Y.; Adachi, S.; Suzuki, Y.; Yagi, N.

    2001-01-01

    We propose a new X-ray methodology for direct observations of the behaviors of single molecular units in real time and real space. This new system, which we call Diffracted X-ray Tracking (DXT), monitors the Brownian motions of a single molecular unit by observations of X-ray diffracted spots from a nanocrystal, tightly bound to the individual single molecular unit in bio-systems. DXT does not determine any translational movements, but only orientational movements

  17. High-performance OPCPA laser system

    International Nuclear Information System (INIS)

    Zuegel, J.D.; Bagnoud, V.; Bromage, J.; Begishev, I.A.; Puth, J.

    2006-01-01

    Optical parametric chirped-pulse amplification (OPCPA) is ideally suited for amplifying ultra-fast laser pulses since it provides broadband gain across a wide range of wavelengths without many of the disadvantages of regenerative amplification. A high-performance OPCPA system has been demonstrated as a prototype for the front end of the OMEGA Extended Performance (EP) Laser System. (authors)

  18. High-performance OPCPA laser system

    Energy Technology Data Exchange (ETDEWEB)

    Zuegel, J.D.; Bagnoud, V.; Bromage, J.; Begishev, I.A.; Puth, J. [Rochester Univ., Lab. for Laser Energetics, NY (United States)

    2006-06-15

    Optical parametric chirped-pulse amplification (OPCPA) is ideally suited for amplifying ultra-fast laser pulses since it provides broadband gain across a wide range of wavelengths without many of the disadvantages of regenerative amplification. A high-performance OPCPA system has been demonstrated as a prototype for the front end of the OMEGA Extended Performance (EP) Laser System. (authors)

  19. Use of neutron diffraction and laser-induced plasma spectroscopy in integrated authentication methodologies of copper alloy artefacts

    International Nuclear Information System (INIS)

    Siano, S.; Bartol, L.; Mencaglia, A.A.; Agresti, J.; Miccio, M.

    2009-01-01

    The present study approaches the general problem of the authentication of copper alloy artefacts of art and historical interest using non-invasive analytical techniques. It aims to demonstrate that a suitable combination of time-of-flight neutron diffraction and laser-induced plasma spectroscopy in integrated multidisciplinary authentication methodologies can provide crucial data for discriminating between genuine archaeological objects and modern counterfeits. After introducing the methodology, which is dedicated in particular to copper alloy figurines of ancient style, two representative authentication case studies are discussed. The results of the work provide evidence that the combination of multiphase analysis using TOF-N D and elemental depth profiles provided by Lips makes it possible to solve most of the present authentication problems.

  20. Documentation of tests on particle size methodologies for laser diffraction compared to traditional sieving and sedimentation analysis

    DEFF Research Database (Denmark)

    Rasmussen, Charlotte; Dalsgaard, Kristian

    Sieving and sedimentation analyses by pipette or hydrometer are historically the traditional methods for determining particle size distributions (PSD). A more informative and faster alternative has for years been laser diffraction (LD). From 2003 to 2013 the authors of this paper have worked...... intensively with PSD and performed various tests and investigations, using LD, sedimentation (by pipette) and sieving. The aim was to improve and understand the relationship between these various techniques, pre-treatment effects and preferably find a unifying correlation factor. As a result, method...... comparisons of LD and sieving/sedimentation are difficult, as LD is a 3D optical volume measurement, sieving is a 2D width measurement, and sedimentation is density dependent. Platy particles like clay are generally measured to be coarser than traditional methods when LD is used. For LD the clay...

  1. Photoelectron diffraction from single oriented molecules: Towards ultrafast structure determination of molecules using x-ray free-electron lasers

    Science.gov (United States)

    Kazama, Misato; Fujikawa, Takashi; Kishimoto, Naoki; Mizuno, Tomoya; Adachi, Jun-ichi; Yagishita, Akira

    2013-06-01

    We provide a molecular structure determination method, based on multiple-scattering x-ray photoelectron diffraction (XPD) calculations. This method is applied to our XPD data on several molecules having different equilibrium geometries. Then it is confirmed that, by our method, bond lengths and bond angles can be determined with a resolution of less than 0.1 Å and 10∘, respectively. Differently from any other scenario of ultrafast structure determination, we measure the two- or three-dimensional XPD of aligned or oriented molecules in the energy range from 100 to 200 eV with a 4π detection velocity map imaging spectrometer. Thanks to the intense and ultrashort pulse properties of x-ray free-electron lasers, our approach exhibits the most probable method for obtaining ultrafast real-time structural information on small to medium-sized molecules consisting of light elements, i.e., a “molecular movie.”

  2. Simple convergent-nozzle aerosol injector for single-particle diffractive imaging with X-ray free-electron lasers

    Directory of Open Access Journals (Sweden)

    R. A. Kirian

    2015-07-01

    Full Text Available A major challenge in high-resolution x-ray free-electron laser-based coherent diffractive imaging is the development of aerosol injectors that can efficiently deliver particles to the peak intensity of the focused X-ray beam. Here, we consider the use of a simple convergent-orifice nozzle for producing tightly focused beams of particles. Through optical imaging we show that 0.5 μm particles can be focused to a full-width at half maximum diameter of 4.2 μm, and we demonstrate the use of such a nozzle for injecting viruses into a micro-focused soft-X-ray FEL beam.

  3. Laser surveillance system for spent fuel

    International Nuclear Information System (INIS)

    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

  4. The Theory of Random Laser Systems

    International Nuclear Information System (INIS)

    Xunya Jiang

    2002-01-01

    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

  5. 'Diffraction-free' optical beams in inverse free electron laser accelerators

    International Nuclear Information System (INIS)

    Cai, S.Y.; Bhattacharjee, A.; Marshall, T.C.

    1988-01-01

    'Diffraction-free' optical beams correspond to exact solutions of the wave equation in free space with the remarkable property that they propagate with negligible transverse spreading for distances much larger than the Rayleigh range. The requirement for this to occur is a large aperture. Using a 2D computer code, we find that these optical beams will also propagate with negligible diffraction even when perturbed by the electron beam in an IFEL; indeed they match well the FEL requirement for the accelerator. The numerical simulations are performed for the proposed facility at Brookhaven in which λ s =10 μm, B=1.5 T (linearly tapered l w =1.31-6.28 cm) and the optical beam power is either 8x10 11 W or 2.3x10 10 W. Approximately 70% of the electrons constituting a beam of current 5 mA or 15 A, radius 0.14 mm and initial energy of 50 MeV is accelerated at 50 MeV/m. (orig.)

  6. A System for Measuring Defect Induced Beam Modulation on Inertial Confinement Fusion-class Laser Optics

    International Nuclear Information System (INIS)

    Runkel, M; Hawley-Fedder, R; Widmayer, C; Williams, W; Weinzapfel, C; Roberts, D

    2005-01-01

    A multi-wavelength laser based system has been constructed to measure defect induced beam modulation (diffraction) from ICF class laser optics. The Nd:YLF-based modulation measurement system (MMS) uses simple beam collimation and imaging to capture diffraction patterns from optical defects onto an 8-bit digital camera at 1053, 527 and 351 nm. The imaging system has a field of view of 4.5 x 2.8 mm 2 and is capable of imaging any plane from 0 to 30 cm downstream from the defect. The system is calibrated using a 477 micron chromium dot on glass for which the downstream diffraction patterns were calculated numerically. Under nominal conditions the system can measure maximum peak modulations of approximately 7:1. An image division algorithm is used to calculate the peak modulation from the diffracted and empty field images after the baseline residual light background is subtracted from both. The peak modulation can then be plotted versus downstream position. The system includes a stage capable of holding optics up to 50 pounds with x and y translation of 40 cm and has been used to measure beam modulation due to solgel coating defects, surface digs on KDP crystals, lenslets in bulk fused silica and laser damage sites mitigated with CO 2 lasers

  7. A System for Measuring Defect Induced Beam Modulation on Inertial Confinement Fusion-class Laser Optics

    Energy Technology Data Exchange (ETDEWEB)

    Runkel, M; Hawley-Fedder, R; Widmayer, C; Williams, W; Weinzapfel, C; Roberts, D

    2005-10-18

    A multi-wavelength laser based system has been constructed to measure defect induced beam modulation (diffraction) from ICF class laser optics. The Nd:YLF-based modulation measurement system (MMS) uses simple beam collimation and imaging to capture diffraction patterns from optical defects onto an 8-bit digital camera at 1053, 527 and 351 nm. The imaging system has a field of view of 4.5 x 2.8 mm{sup 2} and is capable of imaging any plane from 0 to 30 cm downstream from the defect. The system is calibrated using a 477 micron chromium dot on glass for which the downstream diffraction patterns were calculated numerically. Under nominal conditions the system can measure maximum peak modulations of approximately 7:1. An image division algorithm is used to calculate the peak modulation from the diffracted and empty field images after the baseline residual light background is subtracted from both. The peak modulation can then be plotted versus downstream position. The system includes a stage capable of holding optics up to 50 pounds with x and y translation of 40 cm and has been used to measure beam modulation due to solgel coating defects, surface digs on KDP crystals, lenslets in bulk fused silica and laser damage sites mitigated with CO{sub 2} lasers.

  8. Three-dimensional structure determination protocol for noncrystalline biomolecules using x-ray free-electron laser diffraction imaging.

    Science.gov (United States)

    Oroguchi, Tomotaka; Nakasako, Masayoshi

    2013-02-01

    Coherent and intense x-ray pulses generated by x-ray free-electron laser (XFEL) sources are paving the way for structural determination of noncrystalline biomolecules. However, due to the small scattering cross section of electrons for x rays, the available incident x-ray intensity of XFEL sources, which is currently in the range of 10(12)-10(13) photons/μm(2)/pulse, is lower than that necessary to perform single-molecule diffraction experiments for noncrystalline biomolecules even with the molecular masses of megadalton and submicrometer dimensions. Here, we propose an experimental protocol and analysis method for visualizing the structure of those biomolecules by the combined application of coherent x-ray diffraction imaging and three-dimensional reconstruction methods. To compensate the small scattering cross section of biomolecules, in our protocol, a thin vitreous ice plate containing several hundred biomolecules/μm(2) is used as sample, a setup similar to that utilized by single-molecule cryoelectron microscopy. The scattering cross section of such an ice plate is far larger than that of a single particle. The images of biomolecules contained within irradiated areas are then retrieved from each diffraction pattern, and finally provide the three-dimensional electron density model. A realistic atomic simulation using large-scale computations proposed that the three-dimensional structure determination of the 50S ribosomal subunit embedded in a vitreous ice plate is possible at a resolution of 0.8 nm when an x-ray beam of 10(16) photons/500×500 nm(2)/pulse is available.

  9. Beam transport optics for high-power laser systems

    International Nuclear Information System (INIS)

    Taylor, J.R.

    1995-01-01

    Beam transport optics receive output energy from the laser cavity and deliver it to the work site. Depending on the application, this may require a few simple elements or large complex systems. Collection of the laser energy depends on the spatial and temporal energy distribution as well as the wavelength and polarization of the laser cavity and output coupler. Transport optics can perform a variety of functions, including beam formatting, frequency doubling, and distribution to one or more work sites while maintaining or even improving the beam quality. The beam may be delivered to work sites as focused spots or images, projected to distant targets, or propagated through various media for sensing or photochemical processing. Design may involve optical modeling of the system, including diffraction effects and thermal management. A Gaussian beam profile is often used for convenience in modeling. When deviations from this ideal profile need to be considered, it is necessary to characterize the laser beam in detail. Design of the transport system requires understanding of the interaction of the laser energy with optical materials and components. Practical considerations include mounting the optics without stress and with the stability suitable for the intended application. Requirements for beam direction, stability, size, shape, and quality dictate the design approach for each specific situation. Attention also must be given to reliability, environmental, and commercial requirements. Damage to optics in high-power laser systems is a common concern. Environmental problems such as atmospheric turbulence, contamination by dust or vapor from the work site or other sources, or absorption of water vapor can directly degrade beam quality. Other potentially significant optical performance effects may result from instability and aging of the optics, temperature, humidity, pressure, transmitted vibration, and contamination from the work site or other sources

  10. Ultrafast Coherent Diffraction Imaging with X-ray Free-Electron Lasers

    International Nuclear Information System (INIS)

    Chapman, H N; Bajt, S; Barty, A; Benner, W; Bogan, M; Frank, M; Hau-Riege, S; London, R; Marchesini, S; Spiller, E; Szoke, A; Woods, B; Boutet, S; Hodgson, K; Hajdu, J; Bergh, M; Burmeister, F; Caleman, C; Huldt, G; Maia, F; Seibert, M M; der Spoel, D v

    2006-01-01

    The ultrafast pulses from X-ray free-electron lasers will enable imaging of non-periodic objects at near-atomic resolution [1, Neutze]. These objects could include single molecules, protein complexes, or virus particles. The specimen would be completely destroyed by the pulse in a Coulomb explosion, but that destruction will only happen after the pulse. The scattering from the sample will give structural information about the undamaged object. There are many technical challenges that must be addressed before carrying out such experiments at an XFEL, which we are doing so with experiments at FLASH, the soft-X-ray FEL at DESY

  11. Ultra Stable, Industrial Green Tailored Pulse Fiber Laser with Diffraction-limited Beam Quality for Advanced Micromachining

    International Nuclear Information System (INIS)

    Deladurantaye, P; Roy, V; Desbiens, L; Drolet, M; Taillon, Y; Galarneau, P

    2011-01-01

    We report on a novel pulsed fiber laser platform providing pulse shaping agility at high repetition rates and at a wavelength of 532 nm. The oscillator is based on the direct modulation of a seed laser diode followed by a chain of fiber amplifiers. Advanced Large Mode Area (LMA) fiber designs as well as proprietary techniques to mitigate non-linear effects enable output energy per pulse up to 100 μJ at 1064 nm with diffraction-limited beam quality and narrow line widths suitable for efficient frequency conversion. Ultra stable pulses with tailored pulse shapes were demonstrated in the green region of the spectrum at repetition rates higher than 200 kHz. Pulse durations between 2.5 ns and 640 ns are available, as well as pulse to pulse dynamic shape selection at repetition rates up to 1 MHz. The pulse energy stability at 532 nm is better than ± 1.5%, 3σ, over 10 000 pulses. Excellent beam characteristics were obtained. The M 2 parameter is lower than 1.05, the beam waist astigmatism and beam waist asymmetry are below 10% and below 8% respectively, with high stability over time. We foresee that the small spot size, high repetition rate and pulse tailoring capability of this platform will provide advantages to practitioners who are developing novel, advanced processes in many industrially important applications.

  12. Multi-terawatt fusion laser systems

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1993-01-01

    The evolution of laser fusion systems started with a description of the basic principles of the laser in 1959, then a physical demonstration showing 1000 Watts of peak optical power in 1961 to the present systems that deliver 10 14 watts of peak optical power, are presented. Physical limits to large systems are reviewed: thermal limits, material stress limits, structural limits and stability, parasitic coupling, measurement precision and diagnostics. The various steps of the fusion laser-system development process are then discussed through an historical presentation. 3 figs., 8 refs

  13. Lasers

    CERN Document Server

    Milonni, Peter W

    1988-01-01

    A comprehensive introduction to the operating principles and applications of lasers. Explains basic principles, including the necessary elements of classical and quantum physics. Provides concise discussions of various laser types including gas, solid state, semiconductor, and free electron lasers, as well as of laser resonators, diffraction, optical coherence, and many applications including holography, phase conjugation, wave mixing, and nonlinear optics. Incorporates many intuitive explanations and practical examples. Discussions are self-contained in a consistent notation and in a style that should appeal to physicists, chemists, optical scientists and engineers.

  14. Infrared laser scattering system for plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Muraoka, K; Hiraki, N; Kawasaki, S [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

    1975-05-01

    The possibility of observing the collective scattering of infrared laser light from plasmas is discussed in terms of the laser power requirement, the necessary optical system and the detector performance, and is shown to be feasible with the present day techniques to get the ion temperature by means of a CO/sub 2/ laser on theta pinch plasmas. Based on this estimate, the construction of the TEA CO/sub 2/ laser and the preparations of the optical components have been started and some preliminary results of these are described.

  15. Infrared laser scattering system for plasma diagnostics

    International Nuclear Information System (INIS)

    Muraoka, Katsunori; Hiraki, Naoji; Kawasaki, Shoji

    1975-01-01

    The possibility of observing the collective scattering of infrared laser light from plasmas is discussed in terms of the laser power requirement, the necessary optical system and the detector performance, and is shown to be feasible with the present day techniques to get the ion temperature by means of a CO 2 laser on theta pinch plasmas. Based on this estimate, the construction of the TEA CO 2 laser and the preparations of the optical components have been started and some preliminary results of these are described. (auth.)

  16. Multitube coaxial closed cycle gas laser system

    International Nuclear Information System (INIS)

    Davis, J.W.; Walch, A.P.

    1975-01-01

    A gas laser design capable of long term reliable operation in a commercial environment is disclosed. Various construction details which insulate the laser optics from mechanical distortions and vibrations inevitably present in the environment are developed. Also, a versatile optical cavity made up of modular units which render the basic laser configuration adaptable to alternate designs with different output capabilities is shown in detail. The system built around a convection laser operated in a closed cycle and the working medium is a gas which is excited by direct current electric discharges. (auth)

  17. AIP Diffraction measurements using the LHC Beam Loss Monitoring System

    CERN Document Server

    Kalliokoski, Matti

    2017-01-01

    The Beam Loss Monitoring (BLM) system of the Large Hadron Collider protects the machine from beam induced damage by measuring the absorbed dose rates of beam losses, and by triggering beam dump if the rates increase above the allowed threshold limits. Although the detection time scales are optimized for multi-turn losses, information on fast losses can be recovered from the loss data. In this paper, methods in using the BLM system in di ff raction studies are discussed.

  18. Laser systems with diamond optical elements

    International Nuclear Information System (INIS)

    Seitz, J.R.

    1975-01-01

    High power laser systems with optical elements of diamond having a thermal conductivity of at least 10 W/cm. 0 K at 300 0 K and an optical absorption at the laser beam wavelength of no more than 10 to 20 percent are described. (U.S.)

  19. Blue laser phase change recording system

    International Nuclear Information System (INIS)

    Hofmann, Holger; Dambach, S.Soeren; Richter, Hartmut

    2002-01-01

    The migration paths from DVD phase change recording with red laser to the next generation optical disk formats with blue laser and high NA optics are discussed with respect to optical aberration margins and disc capacities. A test system for the evaluation of phase change disks with more than 20 GB capacity is presented and first results of the recording performance are shown

  20. Design and implementation of an optimal laser pulse front tilting scheme for ultrafast electron diffraction in reflection geometry with high temporal resolution

    Directory of Open Access Journals (Sweden)

    Francesco Pennacchio

    2017-07-01

    Full Text Available Ultrafast electron diffraction is a powerful technique to investigate out-of-equilibrium atomic dynamics in solids with high temporal resolution. When diffraction is performed in reflection geometry, the main limitation is the mismatch in group velocity between the overlapping pump light and the electron probe pulses, which affects the overall temporal resolution of the experiment. A solution already available in the literature involved pulse front tilt of the pump beam at the sample, providing a sub-picosecond time resolution. However, in the reported optical scheme, the tilted pulse is characterized by a temporal chirp of about 1 ps at 1 mm away from the centre of the beam, which limits the investigation of surface dynamics in large crystals. In this paper, we propose an optimal tilting scheme designed for a radio-frequency-compressed ultrafast electron diffraction setup working in reflection geometry with 30 keV electron pulses containing up to 105 electrons/pulse. To characterize our scheme, we performed optical cross-correlation measurements, obtaining an average temporal width of the tilted pulse lower than 250 fs. The calibration of the electron-laser temporal overlap was obtained by monitoring the spatial profile of the electron beam when interacting with the plasma optically induced at the apex of a copper needle (plasma lensing effect. Finally, we report the first time-resolved results obtained on graphite, where the electron-phonon coupling dynamics is observed, showing an overall temporal resolution in the sub-500 fs regime. The successful implementation of this configuration opens the way to directly probe structural dynamics of low-dimensional systems in the sub-picosecond regime, with pulsed electrons.

  1. Materials identification using a small-scale pixellated x-ray diffraction system

    International Nuclear Information System (INIS)

    O’Flynn, D; Crews, C; Drakos, I; Christodoulou, C; Speller, R D; Wilson, M D; Veale, M C; Seller, P

    2016-01-01

    A transmission x-ray diffraction system has been developed using a pixellated, energy-resolving detector (HEXITEC) and a small-scale, mains operated x-ray source (Amptek Mini-X). HEXITEC enables diffraction to be measured without the requirement of incident spectrum filtration, or collimation of the scatter from the sample, preserving a large proportion of the useful signal compared with other diffraction techniques. Due to this efficiency, sufficient molecular information for material identification can be obtained within 5 s despite the relatively low x-ray source power. Diffraction data are presented from caffeine, hexamine, paracetamol, plastic explosives and narcotics. The capability to determine molecular information from aspirin tablets inside their packaging is demonstrated. Material selectivity and the potential for a sample classification model is shown with principal component analysis, through which each different material can be clearly resolved. (paper)

  2. System and technique for characterizing fluids using ultrasonic diffraction grating spectroscopy

    Science.gov (United States)

    Greenwood, Margaret S [Richland, WA

    2008-07-08

    A system for determining property of multiphase fluids based on ultrasonic diffraction grating spectroscopy includes a diffraction grating on a solid in contact with the fluid. An interrogation device delivers ultrasound through the solid and a captures a reflection spectrum from the diffraction grating. The reflection spectrum exhibits peaks whose relative size depends on the properties of the various phases of the multiphase fluid. For example, for particles in a liquid, the peaks exhibit dependence on the particle size and the particle volume fraction. Where the exact relationship is know know a priori, data from different peaks of the same reflection spectrum or data from the peaks of different spectra obtained from different diffraction gratings can be used to resolve the size and volume fraction.

  3. Copper Vapor Laser with One-Beam Radiation of Diffraction Quality and Its Capabilities for Microprocessing of Materials for Electronic Engineering Products

    Directory of Open Access Journals (Sweden)

    N. A. Lyabin

    2014-01-01

    Full Text Available The structure, spatial, time and energy characteristics of copper vapor laser radiation (CVL with optical resonators possessing high spatial selectivity have been investigated: with an unstable resonator (UR with two convex mirrors and telescopic UR, and the conditions to form one-beam radiation with diffraction divergence and high stability of directivity pattern axis have been defined.The most weighty and prospective application of CVL with UR with two convex mirrors is to use it as a driving oscillator (DO in a copper vapor laser system (CVLS of the type: driving oscillator – power amplifier (DO – PA when diffraction beam radiating power and power density in a focused spot of 10-20 µm in diameter increases by 1-2 orders. Using industrial sealed-off active elements (AE of “Kulon” series with an average radiation power of 15-25 W as PAs the peak power density increases up to 1011 W/cm 2 while an application of AE “Crystal” with 30- 50 W power gives up to 1012 W/cm 2 , which is sufficient for efficient and qualitative microprocessing of materials up to 1…2 mm thick. Such a CVLS has become the basis for creating up-to-date automated laser technological installations (ALTI of “Karavella-1” and “Karavella-1M” types to manufacture precision parts of electronic engineering products (EEP of metal up to 0.5 mm thick and of non-metal up to 1.5…1.8 mm thick.CVL with a telescopic UR with an average power of 5-6 W diffraction radiation beam has become the basis for creating industrial ALTI “Karavella-2” and “Karavella-2M” to manufacture precision parts of electronic engineering products (EEP of metal up to 0.3 mm thick and of non-metal up to 0.5 – 0.7 mm thick.Practical work on all types of ALTI “Karavella” has shown a set of significant advantages of a laser way of pulsed microprocessing over the traditional ones, including electro-erosion machining: a wide range of structural metal and non-metal materials to be

  4. Magnetically switched power supply system for lasers

    Science.gov (United States)

    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.

  5. Object-oriented wavefront correction in an asymmetric amplifying high-power laser system

    Science.gov (United States)

    Yang, Ying; Yuan, Qiang; Wang, Deen; Zhang, Xin; Dai, Wanjun; Hu, Dongxia; Xue, Qiao; Zhang, Xiaolu; Zhao, Junpu; Zeng, Fa; Wang, Shenzhen; Zhou, Wei; Zhu, Qihua; Zheng, Wanguo

    2018-05-01

    An object-oriented wavefront control method is proposed aiming for excellent near-field homogenization and far-field distribution in an asymmetric amplifying high-power laser system. By averaging the residual errors of the propagating beam, smaller pinholes could be employed on the spatial filters to improve the beam quality. With this wavefront correction system, the laser performance of the main amplifier system in the Shen Guang-III laser facility has been improved. The residual wavefront aberration at the position of each pinhole is below 2 µm (peak-to-valley). For each pinhole, 95% of the total laser energy is enclosed within a circle whose diameter is no more than six times the diffraction limit. At the output of the main laser system, the near-field modulation and contrast are 1.29% and 7.5%, respectively, and 95% of the 1ω (1053 nm) beam energy is contained within a 39.8 µrad circle (6.81 times the diffraction limit) under a laser fluence of 5.8 J cm-2. The measured 1ω focal spot size and near-field contrast are better than the design values of the Shen Guang-III laser facility.

  6. Target isolation system, high power laser and laser peening method and system using same

    Science.gov (United States)

    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.

  7. Double-Sided Laser Heating in Radial Diffraction Geometry for Diamond Anvil Cell Deformation Experiments at Simultaneous High Pressures and Temperatures

    Science.gov (United States)

    Miyagi, L. M.; Kunz, M.; Couper, S.; Lin, F.; Yan, J.; Doran, A.; MacDowell, A. A.

    2017-12-01

    The rheology of rocks and minerals in the Earth's deep interior plays a primary role in controlling large scale geodynamic processes such as mantle convection and slab subduction. Plastic deformation resulting from these processes can lead to texture development and associated seismic anisotropy. If a detailed understanding of the link between deformation and seismic anisotropy is established, observations of seismic anisotropy can be used to understand the dynamic state in the deep Earth. However, performing deformation experiments at lower mantle pressure and temperature conditions are extremely challenging. Thus most deformation studies have been performed either at room temperature and high pressure or at reduced pressures and high temperature. Only a few extraordinary efforts have attained pressures and temperatures relevant to lower mantle. Therefore our ability to interpret observations of lower mantle seismic anisotropy in terms of mantle flow models remains limited. In order to expand the pressure and temperature range available for deformation of deep Earth relevant mineral phases, we have developed a laser heating system for in-situ double-sided heating in radial diffraction geometry at beamline 12.2.2 of the Advanced Light Source of Lawrence Berkeley National Laboratory. This allows texture and lattice strain measurements to be recorded at simultaneous high pressures and temperatures in the diamond anvil cell. This new system is integrated into the newly built axial laser heating system to allow for rapid and reliable transitioning between double-sided laser heating in axial and radial geometries. Transitioning to radial geometry is accomplished by redirecting the laser and imaging paths from 0° and 180° to 90° and 270°. To redirect the 90° path, a motorized periscope mirror pair with an objective lens can be inserted into the downstream axial beam path. The 270° redirection is accomplished by removing the upstream axial objective lens and

  8. Angular correlations of photons from solution diffraction at a free-electron laser encode molecular structure

    International Nuclear Information System (INIS)

    Mendez, Derek; Watkins, Herschel; Qiao, Shenglan; Raines, Kevin S.; Lane, Thomas J.

    2016-01-01

    During X-ray exposure of a molecular solution, photons scattered from the same molecule are correlated. If molecular motion is insignificant during exposure, then differences in momentum transfer between correlated photons are direct measurements of the molecular structure. In conventional small- and wide-angle solution scattering, photon correlations are ignored. This report presents advances in a new biomolecular structural analysis technique, correlated X-ray scattering (CXS), which uses angular intensity correlations to recover hidden structural details from molecules in solution. Due to its intense rapid pulses, an X-ray free electron laser (XFEL) is an excellent tool for CXS experiments. A protocol is outlined for analysis of a CXS data set comprising a total of half a million X-ray exposures of solutions of small gold nanoparticles recorded at the Spring-8 Ångström Compact XFEL facility (SACLA). From the scattered intensities and their correlations, two populations of nanoparticle domains within the solution are distinguished: small twinned, and large probably non-twinned domains. Finally, it is shown analytically how, in a solution measurement, twinning information is only accessible via intensity correlations, demonstrating how CXS reveals atomic-level information from a disordered solution of like molecules.

  9. 5.5 W of Diffraction-Limited Green Light Generated by SFG of Tapered Diode Lasers in a Cascade of Nonlinear Crystals

    DEFF Research Database (Denmark)

    Hansen, Anders Kragh; Jensen, Ole Bjarlin; Andersen, Peter Eskil

    2015-01-01

    Diode-based high power visible lasers are perfect pump sources for, e.g., titaniumsapphire lasers. The combination of favorable scaling laws in both SFG and cascading of nonlinear crystals allows access to unprecedented powers in diode-based systems.......Diode-based high power visible lasers are perfect pump sources for, e.g., titaniumsapphire lasers. The combination of favorable scaling laws in both SFG and cascading of nonlinear crystals allows access to unprecedented powers in diode-based systems....

  10. Intermetallics Synthesis in the Fe–Al System via Layer by Layer 3D Laser Cladding

    Directory of Open Access Journals (Sweden)

    Floran Missemer

    2013-10-01

    Full Text Available Intermetallide phase formation was studied in a powdered Fe–Al system under layer by layer laser cladding with the aim of fabricating the gradient of properties by means of changing the Fe–Al concentration ratio in the powder mixture from layer to layer. The relationships between the laser cladding parameters and the intermetallic phase structures in the consecutively cladded layers were determined. In order to study the structure formation an optical microscopy, X-ray diffraction analysis, measurement of microhardness, scanning electron microscopy (SEM with energy dispersive X-ray (EDX spectroscopy analysis were used after the laser synthesis of intermetallic compounds.

  11. Repetitive output laser system and method using target reflectivity

    International Nuclear Information System (INIS)

    Johnson, R.R.

    1978-01-01

    An improved laser system and method for implosion of a thermonuclear fuel pellet is described 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 refγlection

  12. Laser puncture therapy of nervous system disorders

    Energy Technology Data Exchange (ETDEWEB)

    Anishchenko, G.; Kochetkov, V.

    1984-08-29

    The authors discuss experience with treatment of nervous system disorders by means of laser-puncture therapy. Commenting on the background of the selection of this type of treatment, they explain that once researchers determined the biological action of laser light on specific nerve receptors of the skin, development of laser apparatus capable of concentrating the beam in the millimeter band was undertaken. The devices that are being used for laser-puncture are said to operate in the red helium-neon band of light. The authors identify beam parameters that have been selected for different groups of acupuncture points of the skin, and the courses of treatment (in seconds of radiation) and their time intervals. They go on to discuss the results of treatment of over 800 patients categorized in a group with disorders of the peripheral nervous system and a second group with disorders of the central nervous system.

  13. Coded diffraction system in X-ray crystallography using a boolean phase coded aperture approximation

    Science.gov (United States)

    Pinilla, Samuel; Poveda, Juan; Arguello, Henry

    2018-03-01

    Phase retrieval is a problem present in many applications such as optics, astronomical imaging, computational biology and X-ray crystallography. Recent work has shown that the phase can be better recovered when the acquisition architecture includes a coded aperture, which modulates the signal before diffraction, such that the underlying signal is recovered from coded diffraction patterns. Moreover, this type of modulation effect, before the diffraction operation, can be obtained using a phase coded aperture, just after the sample under study. However, a practical implementation of a phase coded aperture in an X-ray application is not feasible, because it is computationally modeled as a matrix with complex entries which requires changing the phase of the diffracted beams. In fact, changing the phase implies finding a material that allows to deviate the direction of an X-ray beam, which can considerably increase the implementation costs. Hence, this paper describes a low cost coded X-ray diffraction system based on block-unblock coded apertures that enables phase reconstruction. The proposed system approximates the phase coded aperture with a block-unblock coded aperture by using the detour-phase method. Moreover, the SAXS/WAXS X-ray crystallography software was used to simulate the diffraction patterns of a real crystal structure called Rhombic Dodecahedron. Additionally, several simulations were carried out to analyze the performance of block-unblock approximations in recovering the phase, using the simulated diffraction patterns. Furthermore, the quality of the reconstructions was measured in terms of the Peak Signal to Noise Ratio (PSNR). Results show that the performance of the block-unblock phase coded apertures approximation decreases at most 12.5% compared with the phase coded apertures. Moreover, the quality of the reconstructions using the boolean approximations is up to 2.5 dB of PSNR less with respect to the phase coded aperture reconstructions.

  14. Alignment and focusing device for a multibeam laser system

    International Nuclear Information System (INIS)

    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 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 μm and 633 nm) and two for pinholes, should we wish to put an alignment beam backwards through the system

  15. ISOLDE gets a new laser system

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    It's action stations at ISOLDE, the On-Line Isotope Mass Separator at CERN. The Laboratory is preparing to add a second laser ion source system to its arsenal. By alternating between two laser systems, the ISOLDE team will be able to switch from one type of beam to another in record time.   Bruce Marsh, from the EN-STI Group, with one of the lasers from ISOLDE's current system. The first laser source for producing radioactive ion beams (see box) was installed in the ISOLDE hall in the 1990s. This method, which was highly innovative for its time, has since been adopted by several laboratories all over the world. "This laser system allows us to control the ionisation wavelength with precision and thus to select specific atoms in order to produce very pure radioactive ion beams," explains Valentin Fedosseev of the EN Department. "These beams are then used for various experiments, in nuclear astrophysics and biology, for example. With two laser systems we will be able to do ...

  16. The application of diffraction grating in the design of virtual reality (VR) system

    Science.gov (United States)

    Chen, Jiekang; Huang, Qitai; Guan, Min

    2017-10-01

    Virtual Reality (VR) products serve for human eyes ultimately, and the optical properties of VR optical systems must be consistent with the characteristic of human eyes. The monocular coaxial VR optical system is simulated in ZEMAX. A diffraction grating is added to the optical surface next to the eye, and the lights emitted from the diffraction grating are deflected, which can forming an asymmetrical field of view(FOV). Then the lateral chromatic aberration caused by the diffraction grating was corrected by the chromatic dispersion of the prism. Finally, the aspheric surface was added to further optimum design. During the optical design of the system, how to balance the dispersion of the diffraction grating and the prism is the main problem. The balance was achieved by adjusting the parameters of the grating and the prism constantly, and then using aspheric surfaces finally. In order to make the asymmetric FOV of the system consistent with the angle of the visual axis, and to ensure the stereo vision area clear, the smaller half FOV of monocular system is required to reach 30°. Eventually, a system with asymmetrical FOV of 30°+40° was designed. In addition, the aberration curve of the system was analyzed by ZEMAX, and the binocular FOV was calculated according to the principle of binocular overlap. The results show that the asymmetry of FOV of VR monocular optical system can fit to human eyes and the imaging quality match for the human visual characteristics. At the same time, the diffraction grating increases binocular FOV, which decreases the requirement for the design FOV of monocular system.

  17. Diffractive production of ρ-mesons and of ρπ-systems by neutrinos and antineutrinos on protons

    Science.gov (United States)

    Jones, G. T.; Jones, R. W. L.; Kennedy, B. W.; Morrison, D. R. O.; Miller, D. B.; Mobayyen, M. M.; Wainstein, S.; Aderholz, M.; Hantke, D.; Katz, U. F.; Kern, J.; Schmitz, N.; Wittek, W.; Borner, H. P.; Myatt, G.; Bullock, F. W.; Burke, S.

    1993-09-01

    Evidence is presented for diffractive production of ρ-mesons and of ρπ-systems in vp andbar ν p chargedcurrent interactions. In the (anti-)neutrino energy range 10 GeV< E v <60 GeV the cross sections for diffractive ρ and diffractive ρπ production are found to be (0.64±0.14 (stat.)±0.08 (syst.))% and (0.28±0.08 (stat.)±0.04 (syst.))% of the charged-current cross section. The diffractive ρπ signal is consistent with being entirely due to diffractive a 1 production. However, the data cannot distinguish between diffractive a 1 and diffractive nonresonant ρπ production. The experimental distributions of W, Q 2, x Bj and y Bj for diffractive ρ and ρπ events are consistent with model predictions.

  18. Large laser system facility design

    International Nuclear Information System (INIS)

    Gilmartin, T.J.

    1983-01-01

    Optical stability of foundations and support structures, environmental control, close-in subsystem integration, spatial organization, materiel flow and access to remote subsystems is discussed and compared for four laser facilities: The Special Isotope Separation Laboratory, Argus, Shiva/Nova, and Firepond

  19. Laser systems for ablative fractional resurfacing

    DEFF Research Database (Denmark)

    Paasch, Uwe; Haedersdal, Merete

    2011-01-01

    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...

  20. Laser systems for ablative fractional resurfacing

    DEFF Research Database (Denmark)

    Paasch, Uwe; Haedersdal, Merete

    2011-01-01

    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...... 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...

  1. Diffraction of polarized light on periodic structures

    International Nuclear Information System (INIS)

    Bukanina, V; Divakov, D; Tyutyunnik, A; Hohlov, A

    2012-01-01

    Periodic structures as photonic crystals are widely used in modern laser devices, communication technologies and for creating various beam splitters and filters. Diffraction gratings are applied for creating 3D television sets, DVD and Blu-ray drives and reflective structures (Berkley mirror). It is important to simulate diffraction on such structures to design optical systems with predetermined properties based on photonic crystals and diffraction gratings. Methods of simulating diffraction on periodic structures uses theory of Floquet-Bloch and rigorous coupled-wave analysis (RCWA). Current work is dedicated to analysis of photonic band gaps and simulating diffraction on one-dimensional binary diffraction grating using RCWA. The Maxwell's equations for isotropic media and constitutive relations based on the cgs system were used as a model.

  2. Hybrid diffractive-refractive optical system design of head-mounted display for augmented reality

    Science.gov (United States)

    Zhang, Huijuan

    2005-02-01

    An optical see-through head-mounted display for augmented reality is designed in this paper. Considering the factors, such as the optical performance, the utilization ratios of energy of real world and virtual world, the feelings of users when he wears it and etc., a structure of the optical see-through is adopted. With the characteristics of the particular negative dispersive and the power of realizing random-phase modulation, the diffractive surface is helpful for optical system of reducing weight, simplifying structure and etc., and a diffractive surface is introduced in our optical system. The optical system with 25 mm eye relief, 12 mm exit pupil and 20° (H)x15.4° (V) field-of-view is designed. The utilization ratios of energy of real world and virtual world are 1/4 and 1/2, respectively. The angular resolution of display is 0.27 mrad and it less than that of the minimum of human eyes. The diameter of this system is less than 46mm, and it applies the binocular. This diffractive-refractive optical system of see-through head-mounted display not only satisfies the demands of user"s factors in structure, but also with high resolution, very small chromatic aberration and distortion, and satisfies the need of augmented reality. In the end, the parameters of the diffractive surface are discussed.

  3. Wavefront compensation applied to AVLIS laser systems

    International Nuclear Information System (INIS)

    Gonsiorowski, T.; Wirth, A.

    1995-01-01

    The efficiency of an AVLIS system depends upon the power density and uniformity of the laser system. Because of wavefront aberrations the realized beam quality is not ideal. Wavefront compensation provides a means to improve beam quality and system efficiency. (author)

  4. The ARGOS laser system: green light for ground layer adaptive optics at the LBT

    Science.gov (United States)

    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.

  5. Combined resistive and laser heating technique for in situ radial X-ray diffraction in the diamond anvil cell at high pressure and temperature

    Energy Technology Data Exchange (ETDEWEB)

    Miyagi, Lowell [Department of Geology and Geophysics, University of Utah, Salt Lake City, Utah 84112 (United States); Department of Earth Sciences, Montana State University, Bozeman, Montana 59717 (United States); Kanitpanyacharoen, Waruntorn; Kaercher, Pamela; Wenk, Hans-Rudolf; Alarcon, Eloisa Zepeda [Department of Earth and Planetary Science, University of California, Berkeley, California 94720 (United States); Raju, Selva Vennila [Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); HiPSEC, Department of Physics, University of Nevada, Las Vegas, Nevada 89154 (United States); Knight, Jason; MacDowell, Alastair [Advanced Light Source, Lawrence Berkeley Laboratory, Berkeley, California 94720 (United States); Williams, Quentin [Department of Earth and Planetary Science, University of California, Santa Cruz, California 95064 (United States)

    2013-02-15

    To extend the range of high-temperature, high-pressure studies within the diamond anvil cell, a Liermann-type diamond anvil cell with radial diffraction geometry (rDAC) was redesigned and developed for synchrotron X-ray diffraction experiments at beamline 12.2.2 of the Advanced Light Source. The rDAC, equipped with graphite heating arrays, allows simultaneous resistive and laser heating while the material is subjected to high pressure. The goals are both to extend the temperature range of external (resistive) heating and to produce environments with lower temperature gradients in a simultaneously resistive- and laser-heated rDAC. Three different geomaterials were used as pilot samples to calibrate and optimize conditions for combined resistive and laser heating. For example, in Run1, FeO was loaded in a boron-mica gasket and compressed to 11 GPa then gradually resistively heated to 1007 K (1073 K at the diamond side). The laser heating was further applied to FeO to raise temperature to 2273 K. In Run2, Fe-Ni alloy was compressed to 18 GPa and resistively heated to 1785 K (1973 K at the diamond side). The combined resistive and laser heating was successfully performed again on (Mg{sub 0.9}Fe{sub 0.1})O in Run3. In this instance, the sample was loaded in a boron-kapton gasket, compressed to 29 GPa, resistive-heated up to 1007 K (1073 K at the diamond side), and further simultaneously laser-heated to achieve a temperature in excess of 2273 K at the sample position. Diffraction patterns obtained from the experiments were deconvoluted using the Rietveld method and quantified for lattice preferred orientation of each material under extreme conditions and during phase transformation.

  6. ALICE Diffractive Detector Control System for RUN-II in the ALICE Experiment

    CERN Document Server

    INSPIRE-00522336; Martinez, M.I.; Monzon, I. Leon

    2016-01-01

    This paper describes general characteristics of the deployment and commissioned of the Detector Control System (DCS) AD0 for the second phase of the Large Hadron Collider (LHC). The AD0 detector is installed in the ALICE experiment to provide a better selection of diffractive events.

  7. Application of 2-dimensional coordinate system conversion in stress measurements with neutron diffraction

    International Nuclear Information System (INIS)

    Wang, D.-Q.; Hubbard, C.R.; Spooner, S.

    2000-01-01

    This paper will present a method and program to precisely calculate the coordinates in a positioner coordinate system from given sample position coordinates with a minimum number of neutron surface scans for three possible circumstances in stress and texture measurement using neutron diffraction

  8. Microprocessor-based system for automatic X-ray diffraction and fluorescence

    International Nuclear Information System (INIS)

    Souza, A.M. de; Carmo, L.C.S. do; Pereira, V.J.E.; Soares, E.A.

    1984-01-01

    A data acquisition and processing device appropriate for X-ray analysis and goniometer control was built. The Z-80 based system as well as the whole architeture is described. The advantages and new possibilities of the automated instrument as compared to the traditional ones are listed. The X-ray diffraction and fluorescence techniques can take advantage of the automation. (Author) [pt

  9. Classifying and assembling two-dimensional X-ray laser diffraction patterns of a single particle to reconstruct the three-dimensional diffraction intensity function: resolution limit due to the quantum noise

    International Nuclear Information System (INIS)

    Tokuhisa, Atsushi; Taka, Junichiro; Kono, Hidetoshi; Go, Nobuhiro

    2012-01-01

    A new algorithm is developed for reconstructing the high-resolution three-dimensional diffraction intensity function of a globular biological macromolecule from many quantum-noise-limited two-dimensional X-ray laser diffraction patterns, each for an unknown orientation. The structural resolution is expressed as a function of the incident X-ray intensity and quantities characterizing the target molecule. A new two-step algorithm is developed for reconstructing the three-dimensional diffraction intensity of a globular biological macromolecule from many experimentally measured quantum-noise-limited two-dimensional X-ray laser diffraction patterns, each for an unknown orientation. The first step is classification of the two-dimensional patterns into groups according to the similarity of direction of the incident X-rays with respect to the molecule and an averaging within each group to reduce the noise. The second step is detection of common intersecting circles between the signal-enhanced two-dimensional patterns to identify their mutual location in the three-dimensional wavenumber space. The newly developed algorithm enables one to detect a signal for classification in noisy experimental photon-count data with as low as ∼0.1 photons per effective pixel. The wavenumber of such a limiting pixel determines the attainable structural resolution. From this fact, the resolution limit due to the quantum noise attainable by this new method of analysis as well as two important experimental parameters, the number of two-dimensional patterns to be measured (the load for the detector) and the number of pairs of two-dimensional patterns to be analysed (the load for the computer), are derived as a function of the incident X-ray intensity and quantities characterizing the target molecule

  10. Robotic Laser Coating Removal System

    Science.gov (United States)

    2008-07-01

    using a transverse excitation at atmospheric pressure (TEA) method. o Excimer lasers use reactive gases, such as chlorine and fluorine , mixed with... Varnish , and Related Products on Test Panels.   All topcoats were applied over the primer within the manufacturer’s recommended time and  artificially aged

  11. Thermodynamic modelling and in-situ neutron diffraction investigation of the (Ce + Mg + Zn) system

    International Nuclear Information System (INIS)

    Zhu, Zhijun; Gharghouri, Michael A.; Medraj, Mamoun; Lee, Soo Yeol; Pelton, Arthur D.

    2016-01-01

    Highlights: • All phase diagram and thermodynamic data critically assessed for the (Ce + Mg + Zn) system. • All phases described by optimized thermodynamic models. • In-situ neutron diffraction performed to identify phases and transition temperatures. • Assessments of other (RE + Mg + Zn) systems have been carried out simultaneously. • The final product is a thermodynamic database for multicomponent (Mg + RE + Zn) systems. - Abstract: All available phase diagram data for the (Ce + Mg + Zn) system were critically assessed. In-situ neutron diffraction (ND) experiments were performed on selected samples to identify phases and transition temperatures. A critical thermodynamic evaluation and optimization of the (Ce + Mg + Zn) system were carried out and model parameters for the thermodynamic properties of all phases were obtained. The phase transformation behaviour of selected samples was well resolved from the ND experiments and experimental data were used to refine the thermodynamic model parameters.

  12. Dynamical electron diffraction simulation for non-orthogonal crystal system by a revised real space method.

    Science.gov (United States)

    Lv, C L; Liu, Q B; Cai, C Y; Huang, J; Zhou, G W; Wang, Y G

    2015-01-01

    In the transmission electron microscopy, a revised real space (RRS) method has been confirmed to be a more accurate dynamical electron diffraction simulation method for low-energy electron diffraction than the conventional multislice method (CMS). However, the RRS method can be only used to calculate the dynamical electron diffraction of orthogonal crystal system. In this work, the expression of the RRS method for non-orthogonal crystal system is derived. By taking Na2 Ti3 O7 and Si as examples, the correctness of the derived RRS formula for non-orthogonal crystal system is confirmed by testing the coincidence of numerical results of both sides of Schrödinger equation; moreover, the difference between the RRS method and the CMS for non-orthogonal crystal system is compared at the accelerating voltage range from 40 to 10 kV. Our results show that the CMS method is almost the same as the RRS method for the accelerating voltage above 40 kV. However, when the accelerating voltage is further lowered to 20 kV or below, the CMS method introduces significant errors, not only for the higher-order Laue zone diffractions, but also for zero-order Laue zone. These indicate that the RRS method for non-orthogonal crystal system is necessary to be used for more accurate dynamical simulation when the accelerating voltage is low. Furthermore, the reason for the increase of differences between those diffraction patterns calculated by the RRS method and the CMS method with the decrease of the accelerating voltage is discussed. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  13. Laser surveillance system for spent fuel

    International Nuclear Information System (INIS)

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

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a laser system and have used it with a simulated BWR assembly. The reflected signal from the zircaloy rods depends on the position of the assembly, but in all cases is easily discernable from the reference scan of background with no assembly

  14. Fiber laser front end for high energy petawatt laser systems

    International Nuclear Information System (INIS)

    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

    2006-01-01

    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 ∼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

  15. Synchronization control for ultrafast laser parallel microdrilling system

    Science.gov (United States)

    Zhai, Zhongsheng; Kuang, Zheng; Ouyang, Jinlei; Liu, Dun; Perrie, Walter; Edwardson, Stuart P.; Dearden, Geoff

    2014-11-01

    Ultrafast lasers, emitting ultra-short pulses of light, generally of the order of femtoseconds to ten picoseconds, are widely used in micro-processing with the advantage of very little thermal damage. Parallel micro-processing is seen significant developments in laser fabrication, thanking to the spatial light modulator (SLM) which can concert single beam to multiple beams through computer generate holograms (CGHs). However, without synchronization control, on the conditions of changing different holograms or processing on large area beyond scanning galvo's ability, the fabrication will be interrupted constantly for changing holograms and moving the stages. Therefore, synchronization control is very important to improve the convenience and application of parallel micro-processing. A synchronization control method, carried out through two application software: SAMLight (or WaveRunner) and Labview, is presented in this paper. SAMLight is used to control the laser and the scanning galvo to implement microprocessing, and the developed program with Labview is used to control the SLM and motion stages. The synchronization signals, transmitted between the two software, are utilized by a National Instruments (NI) device USB-6008. Using optimal control methods, the synchronized system can easily and automatically accomplish complicated fabrications with minimum time. A multi-drilling application is provided to verify the affectivity of the synchronized control method. It uses multiple annular beams, generated by superimposing multi-beam CGH onto a diffractive axicon CGH, to drill multiple holes at one time, and it can automatically finish different patterns based on synchronization control. This drilling way is an optical trepanning and it avoids huge laser energy waste with attenuation. The multi-beam CGHs, generated by the Grating and Lens algorithm, are different for different patterns. The processing is over 200 times faster than traditional mechanical trepanning

  16. Single-pass high-gain tapered free-electron laser with transverse diffraction in the postsaturation regime

    Directory of Open Access Journals (Sweden)

    Cheng-Ying Tsai

    2018-06-01

    Full Text Available It has been well known that the resonant interaction of an ultrarelativistic electron beam and the radiation field in the single-pass high-gain free electron laser (FEL amplifier leads to the optical gain guiding. The transverse Laplacian term of the slowly varying wave equation in the linear regime can be approximated as a constant detuning parameter, i.e., |∇_{⊥}^{2}|∼k_{R}/z_{R} where k_{R} is the resonant wave number and z_{R} is the Rayleigh range of the laser. In the post-saturation regime, the radiation power begins to oscillate about an equilibrium for the untapered case while continues to grow by undulator tapering. Moreover, in this regime the gain guiding decreases and the simple constant detune is no longer valid. In this paper we study the single-pass high-gain FEL performance in the post-saturation regime with inclusion of diffraction effect and undulator tapering. Our analysis relies upon two constants of motion, one from the energy conservation and the other from the adiabatic invariant of the action variable. By constructing a two-dimensional axisymmetric wave equation and the coupled one-dimensional electron dynamical equations, the performance of a tapered FEL in the postsaturation regime can be analyzed, including the fundamental mode profile, the power efficiency and the scaled energy spread. We begin the analytical investigation with two different axisymmetric electron beam profiles, the uniform and bounded parabolic ones. It is found that the tapered FEL power efficiency can be smaller but close to the taper ratio provided the resonant phase remains constant and the beam-wave is properly matched. Such a tapered efficiency is nearly independent of transverse electron beam size before significant electron detrapping occurs. This is essentially different from the untapered case, where the power extraction efficiency is around the essential FEL gain bandwidth (or ρ, the Pierce or FEL parameter and depends on the beam

  17. System for increasing laser pulse rate

    International Nuclear Information System (INIS)

    1980-01-01

    A technique of static elements is disclosed for combining a plurality of laser beams having time sequenced, pulsed radiation to achieve an augmented pulse rate. The technique may also be applied in a system for combining both time sequenced pulses and frequency distinct pulses for use in a system for isotope enrichment. (author)

  18. Correlation control theory of chaotic laser systems

    International Nuclear Information System (INIS)

    Li Fuli.

    1986-04-01

    A novel control theory of chaotic systems is studied. The correlation functions are calculated and used as feedback signals of the chaotic lasers. Computer experiments have shown that in this way the chaotic systems can be controlled to have time-independent output when the external control parameters are in chaotic domain. (author)

  19. Image digitizer system for bubble chamber laser

    International Nuclear Information System (INIS)

    Haggerty, H.

    1986-01-01

    An IBM PC-based image digitizer system has been assembled to monitor the laser flash used for holography at the 15 foot bubble chamber. The hardware and the operating software are outlined. For an operational test of the system, an array of LEDs was flashed with a 10 microsecond pulse and the image was grabbed by one of the operating programs and processed

  20. Control system for JAERI Free Electron Laser

    International Nuclear Information System (INIS)

    Sugimoto, Masayoshi

    1992-01-01

    A control system comprising of the personal computers network and the CAMAC stations for the JAERI Free Electron Laser is designed and is in the development stage. It controls the equipment and analyzes the electron and optical beam experiments. The concept and the prototype of the control system are described. (author)

  1. Comparative studies of laser annealing technique and furnace annealing by X-ray diffraction and Raman analysis of lithium manganese oxide thin films for lithium-ion batteries

    International Nuclear Information System (INIS)

    Pröll, J.; Weidler, P.G.; Kohler, R.; Mangang, A.; Heißler, S.; Seifert, H.J.; Pfleging, W.

    2013-01-01

    The structure and phase formations of radio frequency magnetron sputtered lithium manganese oxide thin films (Li 1.1 Mn 1.9 O 4 ) under ambient air were studied. The influence of laser annealing and furnace annealing, respectively, on the bulk structure and surface phases was compared by using ex-situ X-ray diffraction and Raman analysis. Laser annealing technique formed a dominant (440)-reflection, furnace annealing led to both, (111)- and (440)-reflections within a cubic symmetry (S.G. Fd3m (227)). Additionally, in-situ Raman and in-situ X-ray diffraction were applied for online detection of phase transformation temperatures. In-situ X-ray diffraction measurements clearly identified the starting temperature for the (111)- and (440)-reflections around 525 °C and 400 °C, respectively. The 2θ Bragg peak positions of the characteristic (111)- and (440)-reflections were in good agreement with those obtained through conventional furnace annealing. Laser annealing of lithium manganese oxide films provided a quick and efficient technique and delivered a dominant (440)-reflection which showed the expected electrochemical behavior of the well-known two-step de-/intercalation process of lithium-ions into the cubic spinel structure within galvanostatic testing and cyclic voltammetry. - Highlights: ► Formation of cubic spinel-like phase of Li–Mn–O thin films by rapid laser annealing ► Laser annealing at 680 °C and 100 s was demonstrated as quick crystallization method. ► 400 °C was identified as characteristic onset temperature for (440)-reflex formation

  2. PHASE NOISE COMPARISON OF SHORT PULSE LASER SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Problems in the development of autonomous mobile laser systems based on a cw chemical DF laser

    International Nuclear Information System (INIS)

    Aleksandrov, B P; Bashkin, A S; Beznozdrev, V N; Parfen'ev, M V; Pirogov, N A; Semenov, S N

    2003-01-01

    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. Vacuum mechatronic laser alignment system on the Nova laser

    International Nuclear Information System (INIS)

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

    1991-11-01

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

  5. A novel automotive headlight system based on digital micro-mirror devices and diffractive optical elements

    Science.gov (United States)

    Su, Ping; Song, Yuming; Ma, Jianshe

    2018-01-01

    The DMD (Digital Micro-mirror Device) has the advantages of high refresh rate and high diffraction efficiency, and these make it become an ideal loader of multiple modes illumination. DOEs (Diffractive Optical Element) have the advantages of high degree of freedom, light weight, easy to copy, low cost etc., and can be used to reduce the weight, complexity, cost of optical system. A novel automotive headlamp system using DMD as the light distribution element and a DOE as the light field modulation device is proposed in this paper. The pure phase DOE is obtained by the GS algorithm using Rayleigh-Sommerfeld diffraction integral model. Based on the standard automotive headlamp light intensity distribution in the target plane, the amplitude distribution of DMD is obtained by numerical simulation, and the grayscale diagram loaded on the DMD can be obtained accordingly. Finally, according to simulation result, the light intensity distribution in the target plane is proportional to the national standard, hence verifies the validity of the novel system. The novel illumination system proposed in this paper provides a reliable hardware platform for the intelligent headlamps.

  6. The copper-pumped dye laser system at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Hackel, R.P.; Warner, B.E.

    1993-01-01

    The Lawrence Livermore National Laboratory's (LLNL) Atomic Vapor Laser Isotope Separation (AVLIS) Program has developed a high-average-power, pulsed, tunable, visible laser system. Testing of this hardware is in progress at industrial scale. The LLNL copper-dye laser system is prototypical of a basic module of a uranium-AVLIS plant. The laser demonstration facility (LDF) system consists of copper vapor lasers arranged in oscillator-amplifier chains providing optical pump power to dye-laser master-oscillator-power-amplifier chains. This system is capable of thousands of watts (average) tunable between 550 and 650 mm. The copper laser system at LLNL consists of 12 chains operating continuously. The copper lasers operate at nominally 4.4 kHz, with 50 ns pulse widths and produce 20 W at near the diffraction limit from oscillators and >250 W from each amplifier. Chains consist of an oscillator and three amplifiers and produce >750 W average, with availabilities >95% (i.e., >8,300 h/y). The total copper laser system power averages ∼9,000 W and has operated at over 10,000 W for extended intervals. The 12 copper laser beams are multiplexed and delivered to the dye laser system where they pump multiple dye laser chains. Each dye chain consists of a master oscillator and three or four power amplifiers. The master oscillator operates at nominally 100 mW with a 50 MHz single mode bandwidth. Amplifiers are designed to efficiently amplify the dye beam with low ASE content and high optical quality. Sustained dye chain powers are up to 1,400 W with dye conversion efficiency >50%, ASE content <5%, and wavefront quality correctable to <λ/10 RMS, using deformable mirrors. Since the timing of the copper laser chains can be offset, the dye laser system is capable of repetition rates which are multiples of 4.4 kHz, up to 26 kHz, limited by the dye pumping system. Development of plant-scale copper and dye laser hardware is progressing in off-line facilities

  7. Short-time X-ray diffraction with an efficient-optimized, high repetition-rate laser-plasma X-ray-source; Kurzzeit-Roentgenbeugung mit Hilfe einer Effizienz-optimierten, hochrepetierenden Laser-Plasma-Roentgenquelle

    Energy Technology Data Exchange (ETDEWEB)

    Kaehle, Stephan

    2009-04-23

    This thesis deals with the production and application of ultrashort X-ray pulses. In the beginning different possibilities for the production of X-ray pulses with pulse durations of below one picosecond are presented, whereby the main topic lies on the so called laser-plasma X-ray sources with high repetition rate. In this case ultrashort laser pulses are focused on a metal, so that in the focus intensities of above 10{sup 16} W/cm{sup 2} dominate. In the ideal case in such way ultrafast electrons are produced, which are responsible for line radiation. In these experiments titanium K{sub {alpha}} radiation is produced, thes photons possess an energy of 4.51 keV. For the efficient production of line radiation here the Ti:Sa laser is optimized in view of the laser energy and the pulse shape and the influence of the different parameters on the K{sub {alpha}} production systematically studied. The influences of laser intensity, system-conditioned pre-pulses and of phase modulation are checked. It turns out that beside the increasement of the K{sub {alpha}} radiation by a suited laser intensity a reduction of the X-ray background radiation is of deciding importance for the obtaining of clear diffraction images. This background radiation is mainly composed of bremsstrahlung. It can be suppressed by the avoidance of intrinsic pre-pulses and by means of 2nd-order phase modulation. By means of optical excitation and X-ray exploration experiments the production of acoustic waves after ultrashort optical excitation in a 150 nm thick Ge(111) film on Si(111) is studied. These acoustic waves are driven by thermal (in this time scale time-independent) and electronic (time dependent) pressure amounts. As essential results it turns out that the relative amount of the electronic pressure increases with decreasing excitation density. [German] Diese Arbeit befasst sich mit der Erzeugung und Anwendung ultrakurzer Roentgenimpulse. Zu Beginn werden verschiedene Moeglichkeiten zur

  8. Laser fusion system design study. Final report

    International Nuclear Information System (INIS)

    1975-01-01

    The following studies were completed: (1) The synthesis of a pointing/control system compatible with existing and advanced laser opto-mechanical configurations. (2) Attainment of the required pointing angle, longitudinal focus, and differential pathlength accuracies. (3) Maximum modularization of the sensor and gimbal assemblies to provide the required accuracies at minimum cost. Detailed information is given on each. (MOW)

  9. Electronic Subsystems For Laser Communication System

    Science.gov (United States)

    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.

  10. MBE System for Antimonide Based Semiconductor Lasers

    National Research Council Canada - National Science Library

    Lester, Luke

    1999-01-01

    .... SLR-770 inductively coupled plasma (ICP) processing system. The SLR-770 has been invaluable in the study of plasma etching of AlGaAsSb and GaSb-materials that form the backbone of antimonide-based semiconductor lasers...

  11. Diode laser in-band pumped, efficient 1645 nm continuous-wave and Q-switched Er:YLuAG lasers with near-diffraction-limited beam quality

    International Nuclear Information System (INIS)

    Li, Jing; Yang, SuHui; He, Tao

    2014-01-01

    Fiber-like Er:YLuAG laser rods were tested for continuous-wave (CW) and Q-switched operation. Two narrow-band laser diodes emitting at 1532 nm were used as pump sources. The pump power was confined in the laser rods via total internal reflection. In CW mode, a maximum output power of 7.2 W was measured from a 30 mm long Er:YLuAG laser rod, corresponding to an optical–optical efficiency of 26% and a slope efficiency of 78%. Er:YLuAG and Er:YAG lasers were compared experimentally and exhibited comparable performance, while the measured central wavelength of the Er:YLuAG laser was 1644.75 nm, slightly longer than the central wavelength of the Er:YAG laser in the same experimental circumstances. In Q-switched mode, an output energy of 3.5 mJ was obtained from a 25 mm Er:YLuAG laser rod with a pulse duration of 100 ns and a pulse repetition frequency of 100 Hz. The pulsed output had near-diffraction-limited beam quality with M 2 values of 1.13 and 1.11 in the x and y directions, respectively. (letter)

  12. [Hyperopic Laser-in-situ-Keratomileusis after trifocal intraocular lens implantation : Aberration-free femto-Laser-in-situ-Keratomileusis treatment after implantation of a diffractive, multifocal, toric intraocular lens-case analysis].

    Science.gov (United States)

    Hemkeppler, E; Böhm, M; Kohnen, T

    2018-05-29

    A 52-year-old highly myopic female patient was implanted with a multifocal, diffractive, toric intraocular lens because of the wish to be independent of eyeglasses. Despite high-quality, extensive preoperative examinations, a hyperopic refractive error remained postoperatively, which led to the patient's dissatisfaction. This error was treated with Laser-in-situ-Keratomileusis (LASIK). After corneal LASIK treatment and implantation of a diffractive toric multifocal intraocular lens the patient showed a good postoperative visual result without optical phenomena.

  13. Ray tracing through the liquid crystal point diffraction interferometer. 1998 summer research program for high school juniors at the University of Rochester's Laboratory for Laser Energetics. Student research reports

    International Nuclear Information System (INIS)

    Turner, A.

    1999-03-01

    The Omega laser is a system with many different parts that may cause imperfections. There are a multitude of lenses and mirrors, for example, that may not be polished correctly and can cause the laser wave front to have aberrations. The Liquid Crystal Point Diffraction Interferometer (L.C.P.D.I.) is a device whose main purpose is to read the wave front of the laser and measure any aberrations that may be on it. The way the L.C.P.D.I. reads the laser wave front and measures these aberrations is very complicated and has yet to be perfected. A ray-tracing model of the L.C.P.D.I. has been built, which calculates and models the ray trajectories, the optical paths of the rays, the O.P.D. between the object and reference beams, the absorption of the rays in the liquid crystal, and the intensities of each beam. It can predict an actual experiment by manipulating the different parameters of the program. It will be useful in optimization and further development of the L.C.P.D.I. Evidently, it is necessary to develop a liquid crystal solution with an O.D. greater than 0.3, and possibly as high as 2.0. This new solution would be able to reduce the intensity of the object beam sufficiently to make it comparable with the reference beam intensity. If this were achieved, the contrast, or visibility of the fringes would be better, and the interferogram could be used to diagnose the aberrations in the laser beam front. Then the cause of the aberrations could be fixed. This would result in a near-perfect laser front. If this were achieved, then it is possible that laser fusion could be made more efficient and possibly used as an energy source

  14. Self-action of continuous laser radiation and Pearcey diffraction in a water suspension with light-absorbing particles

    DEFF Research Database (Denmark)

    Angelsky, O. V.; Bekshaev, A. Ya.; Maksimyak, P. P.

    2014-01-01

    -diffraction of the incident light, here being strongly sensitive to the medium position with respect to the focus. This technique, based on the complex spatial structure of both the incident and the diffracted fields, can be employed for the detection and measurement of weak non-linearities....

  15. Infrared laser scattering system for the plasma diagnostics

    International Nuclear Information System (INIS)

    Hiraki, Naoji; Kawasaki, Shoji; Muraoka, Katsunori

    1975-01-01

    As the results of the parametric studies of the double discharge TEA CO 2 laser, the required properties on the laser system for the scattering diagnostics of plasmas are shown to be realized with our CO 2 laser. The direction of the future improvements of the laser performance is also discussed. (auth.)

  16. Five Wavelength DFB Fibre Laser Source for WDM Systems

    DEFF Research Database (Denmark)

    Hübner, Jörg; Varming, Poul; Kristensen, Martin

    1997-01-01

    Singlemode UV-induced distributed feedback (DFB) fibre lasers with a linewidth of lasers is verified by a 10 Gbit/s transmission experiment. Five DFB fibre lasers are cascaded and pumped by a single...... semiconductor laser, thereby forming a multiwavelength source for WDM systems...

  17. Contrast image formation based on thermodynamic approach and surface laser oxidation process for optoelectronic read-out system

    Science.gov (United States)

    Scherbak, Aleksandr; Yulmetova, Olga

    2018-05-01

    A pulsed fiber laser with the wavelength 1.06 μm was used to treat titanium nitride film deposited on beryllium substrates in the air with intensities below an ablation threshold to provide oxide formation. Laser oxidation results were predicted by the chemical thermodynamic method and confirmed by experimental techniques (X-ray diffraction). The developed technology of contrast image formation is intended to be used for optoelectronic read-out system.

  18. Evolution of shiva laser alignment systems

    International Nuclear Information System (INIS)

    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 16 W/cm 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

  19. Protein structure determination by single-wavelength anomalous diffraction phasing of X-ray free-electron laser data

    Directory of Open Access Journals (Sweden)

    Karol Nass

    2016-05-01

    Full Text Available Serial femtosecond crystallography (SFX at X-ray free-electron lasers (XFELs offers unprecedented possibilities for macromolecular structure determination of systems that are prone to radiation damage. However, phasing XFEL data de novo is complicated by the inherent inaccuracy of SFX data, and only a few successful examples, mostly based on exceedingly strong anomalous or isomorphous difference signals, have been reported. Here, it is shown that SFX data from thaumatin microcrystals can be successfully phased using only the weak anomalous scattering from the endogenous S atoms. Moreover, a step-by-step investigation is presented of the particular problems of SAD phasing of SFX data, analysing data from a derivative with a strong anomalous signal as well as the weak signal from endogenous S atoms.

  20. Diffractive production of p-mesons and of pπ-systems by neutrinos and antineutrinos on protons

    International Nuclear Information System (INIS)

    Jones, G.T.; Jones, R.W.L.; Kennedy, B.W.; Morrison, D.R.O.; Borner, H.P.; Myatt, G.; Bullock, F.W.; Burke, S.

    1993-01-01

    Evidence is presented for diffractive production of ρ-mesons and of ρπ-systems in νp and anti νp charged-current interactions. In the (anti-)neutrino energy range 10 GeV ν 1 production. However, the data cannot distinguish between diffractive a 1 and diffractive nonresonant ρπ production. The experimental distributions of W, Q 2 , x Bj and y Bj for diffractive ρ and ρπ events are consistent with model predictions. (orig.)

  1. Recent laser experiments on the Aurora KrF/ICF laser system

    International Nuclear Information System (INIS)

    Turner, T.P.; Jones, J.E.; Czuchlewski, S.J.; Watt, R.G.; Thomas, S.J.; Kang, M.; Tallman, C.R.; Mack, J.M.; Figueira, J.F.

    1990-01-01

    The Aurora KrF/ICF Laser Facility at Los Alamos is operational at the kilojoule-level for both laser and target experiments. We report on recent laser experiments on the system and resulting system improvements. 3 refs., 4 figs

  2. Laser Safety and Hazard Analysis for the Trailer (B70) Based AURA Laser System

    International Nuclear Information System (INIS)

    AUGUSTONI, ARNOLD L.

    2003-01-01

    A laser safety and hazard analysis was performed for the AURA laser system based on the 2000 version of the American National Standards Institute's (ANSI) Standard Z136.1, for ''Safe Use of Lasers'' and the 2000 version of the ANSI Standard Z136.6, for ''Safe Use of Lasers Outdoors''. The trailer based AURA laser system is a mobile platform, which is used to perform laser interaction experiments and tests at various national test sites. The trailer (B70) based AURA laser system is generally operated on the United State Air Force Starfire Optical Range (SOR) at Kirtland Air Force Base (KAFB), New Mexico. The laser is used to perform laser interaction testing inside the laser trailer as well as outside the trailer at target sites located at various distances from the exit telescope. In order to protect personnel, who work inside the Nominal Hazard Zone (NHZ), from hazardous laser emission exposures it was necessary to determine the Maximum Permissible Exposure (MPE) for each laser wavelength (wavelength bands) and calculate the appropriate minimum Optical Density (OD min ) of the laser safety eyewear used by authorized personnel and the Nominal Ocular Hazard Distance (NOHD) to protect unauthorized personnel who may have violated the boundaries of the control area and enter into the laser's NHZ

  3. 21 CFR 884.6200 - Assisted reproduction laser system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction laser system. 884.6200... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a device...

  4. Commercialization plan laser-based decoating systems

    International Nuclear Information System (INIS)

    Freiwald, J.; Freiwald, D.A.

    1998-01-01

    F2 Associates Inc. (F2) is a small, high-technology firm focused on developing and commercializing environmentally friendly laser ablation systems for industrial-rate removal of surface coatings from metals, concrete, and delicate substrates such as composites. F2 has a contract with the US Department of Energy Federal Energy Technology Center (FETC) to develop and test a laser-based technology for removing contaminated paint and other contaminants from concrete and metal surfaces. Task 4.1 in Phase 2 of the Statement of Work for this DOE contract requires that F2 ''document its plans for commercializing and marketing the stationary laser ablation system. This document shall include a discussion of prospects for commercial customers and partners and may require periodic update to reflect changing strategy. This document shall be submitted to the DOE for review.'' This report is being prepared and submitted in fulfillment of that requirement. This report describes the laser-based technology for cleaning and coatings removal, the types of laser-based systems that have been developed by F2 based on this technology, and the various markets that are emerging for this technology. F2's commercialization and marketing plans are described, including how F2's organization is structured to meet the needs of technology commercialization, F2's strategy and marketing approach, and the necessary steps to receive certification for removing paint from aircraft and DOE certification for D and D applications. The future use of the equipment built for the DOE contract is also discussed

  5. Phase Noise Comparision of Short Pulse Laser Systems

    Energy Technology Data Exchange (ETDEWEB)

    S. Zhang; S. V. Benson; J. Hansknecht; D. Hardy; G. Neil; Michelle D. Shinn

    2006-12-01

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

  6. Method and system for communicating with a laser power driver

    Science.gov (United States)

    Telford, Steven

    2017-07-18

    A system for controlling a plurality of laser diodes includes an optical transmitter coupled to the laser diode driver for each laser diode. An optical signal including bi-phase encoded data is provided to each laser diode driver. The optical signal includes current level and pulse duration information at which each of the diodes is to be driven. Upon receiving a trigger signal, the laser diode drivers operate the laser diodes using the current level and pulse duration information to output a laser beam.

  7. X-ray Diffraction from Isolated and Strongly Aligned Gas-Phase Molecules with a Free-Electron Laser

    DEFF Research Database (Denmark)

    Küpper, Jochen; Stern, Stephan; Holmegaard, Lotte

    2014-01-01

    We report experimental results on x-ray diffraction of quantum-state-selected and strongly aligned ensembles of the prototypical asymmetric rotor molecule 2,5-diiodobenzonitrile using the Linac Coherent Light Source. The experiments demonstrate first steps toward a new approach to diffractive...... imaging of distinct structures of individual, isolated gas-phase molecules. We confirm several key ingredients of single molecule diffraction experiments: the abilities to detect and count individual scattered x-ray photons in single shot diffraction data, to deliver state-selected, e. g., structural......-isomer-selected, ensembles of molecules to the x-ray interaction volume, and to strongly align the scattering molecules. Our approach, using ultrashort x-ray pulses, is suitable to study ultrafast dynamics of isolated molecules....

  8. System of laser pump and synchrotron radiation probe microdiffraction to investigate optical recording process

    International Nuclear Information System (INIS)

    Yasuda, Nobuhiro; Fukuyama, Yoshimitsu; Osawa, Hitoshi; Kimura, Shigeru; Ito, Kiminori; Tanaka, Yoshihito; Matsunaga, Toshiyuki; Kojima, Rie; Hisada, Kazuya; Tsuchino, Akio; Birukawa, Masahiro; Yamada, Noboru; Sekiguchi, Koji; Fujiie, Kazuhiko; Kawakubo, Osamu; Takata, Masaki

    2013-01-01

    We have developed a system of laser-pump and synchrotron radiation probe microdiffraction to investigate the phase-change process on a nanosecond time scale of Ge 2 Sb 2 Te 5 film embedded in multi-layer structures, which corresponds to real optical recording media. The measurements were achieved by combining (i) the pump-laser system with a pulse width of 300 ps, (ii) a highly brilliant focused microbeam with wide peak-energy width (ΔE/E ∼ 2%) made by focusing helical undulator radiation without monochromatization, and (iii) a precise sample rotation stage to make repetitive measurements. We successfully detected a very weak time-resolved diffraction signal by using this system from 100-nm-thick Ge 2 Sb 2 Te 5 phase-change layers. This enabled us to find the dependence of the crystal-amorphous phase change process of the Ge 2 Sb 2 Te 5 layers on laser power.

  9. Nondestructive strain depth profiling with high energy X-ray diffraction: System capabilities and limitations

    Science.gov (United States)

    Zhang, Zhan; Wendt, Scott; Cosentino, Nicholas; Bond, Leonard J.

    2018-04-01

    Limited by photon energy, and penetration capability, traditional X-ray diffraction (XRD) strain measurements are only capable of achieving a few microns depth due to the use of copper (Cu Kα1) or molybdenum (Mo Kα1) characteristic radiation. For deeper strain depth profiling, destructive methods are commonly necessary to access layers of interest by removing material. To investigate deeper depth profiles nondestructively, a laboratory bench-top high-energy X-ray diffraction (HEXRD) system was previously developed. This HEXRD method uses an industrial 320 kVp X-Ray tube and the Kα1 characteristic peak of tungsten, to produces a higher intensity X-ray beam which enables depth profiling measurement of lattice strain. An aluminum sample was investigated with deformation/load provided using a bending rig. It was shown that the HEXRD method is capable of strain depth profiling to 2.5 mm. The method was validated using an aluminum sample where both the HEXRD method and the traditional X-ray diffraction method gave data compared with that obtained using destructive etching layer removal, performed by a commercial provider. The results demonstrate comparable accuracy up to 0.8 mm depth. Nevertheless, higher attenuation capabilities in heavier metals limit the applications in other materials. Simulations predict that HEXRD works for steel and nickel in material up to 200 µm, but experiment results indicate that the HEXRD strain profile is not practical for steel and nickel material, and the measured diffraction signals are undetectable when compared to the noise.

  10. Construction of a large laser fusion system

    International Nuclear Information System (INIS)

    Hurley, C.A.

    1977-01-01

    Construction of a large laser fusion machine is nearing completion at the Lawrence Livermore Laboratory (LLL). Shiva, a 20-terawatt neodymium doped glass system, will be complete in early 1978. This system will have the high power needed to demonstrate significant thermonuclear burn. Shiva will irradiate a microscopic D-T pellet with 20 separate laser beams arriving simultaneously at the target. This requires precise alignment, and stability to maintain alignment. Hardware for the 20 laser chains is composed of 140 amplifiers, 100 spatial filters, 80 isolation stages, 40 large turning mirrors, and a front-end splitter system of over 100 parts. These are mounted on a high stability, three dimensional spaceframe which serves as an optical bench. The mechanical design effort, spanning approximately 3 years, followed a classic engineering evolution. The conceptual design phase led directly to system optimization through cost and technical tradeoffs. Additional manpower was then required for detailed design and specification of hardware and fabrication. Design of long-lead items was started early in order to initiate fabrication and assembly while the rest of the design was completed. All components were ready for assembly and construction as fiscal priorities and schedules permitted

  11. Single-crystal neutron diffraction studies of hydrogen-bonded systems: Two recent examples from IPNS

    Energy Technology Data Exchange (ETDEWEB)

    Koetzle, Thomas F. [IPNS Division, Argonne National Laboratory, Argonne, IL 60439 (United States)], E-mail: tkoetzle@anl.gov; Piccoli, Paula M.B.; Schultz, Arthur J. [IPNS Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2009-02-21

    Beginning with work in the 1950s at the first generation of research reactors, studies of hydrogen-bonded systems have been a prime application for single-crystal neutron diffraction. The range of systems studied was extended in the 1960s and 1970s, with the advent of high flux reactor sources, and beginning around 1980 studies at pulsed neutron sources have made increasingly important contributions. Recently at the Argonne Intense Pulsed Neutron Source (IPNS), working with collaborators, we completed two studies of hydrogen-bonded systems that will serve to illustrate topics of current interest. In the first study, on andrographolide, an active diterpenoid natural product, our neutron diffraction results definitively characterize the hydrogen-bonding interactions. The second IPNS study is on tetraacetylethane (TAE), a {beta}-diketone enol system with a very short, strong intramolecular O-H...O hydrogen bond. At IPNS, we have determined the neutron crystal structure of TAE at five temperatures between 20 and 298 K to investigate changes in the structure with temperature and to probe for disorder. Despite the successes illustrated by the two examples presented here and by many other studies, at present applications of single-crystal neutron diffraction continue to be extremely flux limited and constrained by the requirement for mm-size crystals for many problems. These limitations are being addressed through the realization of powerful instruments at a new generation of pulsed neutron sources, including in the USA the TOPAZ and MaNDi single-crystal diffractometers that are under development at the Spallation Neutron Source (SNS)

  12. Single-crystal neutron diffraction studies of hydrogen-bonded systems: Two recent examples from IPNS

    Science.gov (United States)

    Koetzle, Thomas F.; Piccoli, Paula M. B.; Schultz, Arthur J.

    2009-02-01

    Beginning with work in the 1950s at the first generation of research reactors, studies of hydrogen-bonded systems have been a prime application for single-crystal neutron diffraction. The range of systems studied was extended in the 1960s and 1970s, with the advent of high flux reactor sources, and beginning around 1980 studies at pulsed neutron sources have made increasingly important contributions. Recently at the Argonne Intense Pulsed Neutron Source (IPNS), working with collaborators, we completed two studies of hydrogen-bonded systems that will serve to illustrate topics of current interest. In the first study, on andrographolide, an active diterpenoid natural product, our neutron diffraction results definitively characterize the hydrogen-bonding interactions. The second IPNS study is on tetraacetylethane (TAE), a β-diketone enol system with a very short, strong intramolecular O-H⋯O hydrogen bond. At IPNS, we have determined the neutron crystal structure of TAE at five temperatures between 20 and 298 K to investigate changes in the structure with temperature and to probe for disorder. Despite the successes illustrated by the two examples presented here and by many other studies, at present applications of single-crystal neutron diffraction continue to be extremely flux limited and constrained by the requirement for mm-size crystals for many problems. These limitations are being addressed through the realization of powerful instruments at a new generation of pulsed neutron sources, including in the USA the TOPAZ and MaNDi single-crystal diffractometers that are under development at the Spallation Neutron Source (SNS).

  13. Single-crystal neutron diffraction studies of hydrogen-bonded systems: Two recent examples from IPNS

    International Nuclear Information System (INIS)

    Koetzle, Thomas F.; Piccoli, Paula M.B.; Schultz, Arthur J.

    2009-01-01

    Beginning with work in the 1950s at the first generation of research reactors, studies of hydrogen-bonded systems have been a prime application for single-crystal neutron diffraction. The range of systems studied was extended in the 1960s and 1970s, with the advent of high flux reactor sources, and beginning around 1980 studies at pulsed neutron sources have made increasingly important contributions. Recently at the Argonne Intense Pulsed Neutron Source (IPNS), working with collaborators, we completed two studies of hydrogen-bonded systems that will serve to illustrate topics of current interest. In the first study, on andrographolide, an active diterpenoid natural product, our neutron diffraction results definitively characterize the hydrogen-bonding interactions. The second IPNS study is on tetraacetylethane (TAE), a β-diketone enol system with a very short, strong intramolecular O-H...O hydrogen bond. At IPNS, we have determined the neutron crystal structure of TAE at five temperatures between 20 and 298 K to investigate changes in the structure with temperature and to probe for disorder. Despite the successes illustrated by the two examples presented here and by many other studies, at present applications of single-crystal neutron diffraction continue to be extremely flux limited and constrained by the requirement for mm-size crystals for many problems. These limitations are being addressed through the realization of powerful instruments at a new generation of pulsed neutron sources, including in the USA the TOPAZ and MaNDi single-crystal diffractometers that are under development at the Spallation Neutron Source (SNS).

  14. Optimization of an X-ray diffraction imaging system for medical and security applications

    International Nuclear Information System (INIS)

    Marticke, Fanny

    2016-01-01

    X-ray diffraction imaging is a powerful noninvasive technique to identify or characterize different materials. Compared to traditional techniques using X-ray transmission, it allows to extract more material characteristic information, such as the Bragg peak positions for crystalline materials as well as the molecular form factor for amorphous materials. The potential of this technique has been recognized by many researchers and numerous applications such as luggage inspection, nondestructive testing, drug detection and biological tissue characterization have been proposed. The method of energy dispersive X-ray diffraction (EDXRD) is particularly suited for this type of applications as it allows the use of a conventional X-ray tube, the acquisition of the whole spectrum at the same time and parallelized architectures to inspect an entire object in a reasonable time. The purpose of the present work is to optimize the whole material characterization chain. Optimization comprises two aspects: optimization of the acquisition system and of data processing. The last one concerns especially the correction of diffraction pattern degraded by acquisition process. Reconstruction methods are proposed and validated on simulated and experimental spectra. System optimization is realized using figures of merit such as detective quantum efficiency (DQE), contrast to noise ratio (CNR) and receiver operating characteristic (ROC) curves.The first chosen application is XRD based breast imaging which aims to distinguish cancerous tissues from healthy tissues. Two non-multiplexed collimation configurations combining EDXRD and ADXRD are proposed after optimization procedure. A simulation study of the whole system and a breast phantom was realized to determine the required dose to detect a 4 mm carcinoma nodule. The second application concerns detection of illicit materials during security check. The possible benefit of a multiplexed collimation system was examined. (author) [fr

  15. Ultra-high accuracy optical testing: creating diffraction-limitedshort-wavelength optical systems

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, Kenneth A.; Naulleau, Patrick P.; Rekawa, Senajith B.; Denham, Paul E.; Liddle, J. Alexander; Gullikson, Eric M.; Jackson, KeithH.; Anderson, Erik H.; Taylor, John S.; Sommargren, Gary E.; Chapman,Henry N.; Phillion, Donald W.; Johnson, Michael; Barty, Anton; Soufli,Regina; Spiller, Eberhard A.; Walton, Christopher C.; Bajt, Sasa

    2005-08-03

    Since 1993, research in the fabrication of extreme ultraviolet (EUV) optical imaging systems, conducted at Lawrence Berkeley National Laboratory (LBNL) and Lawrence Livermore National Laboratory (LLNL), has produced the highest resolution optical systems ever made. We have pioneered the development of ultra-high-accuracy optical testing and alignment methods, working at extreme ultraviolet wavelengths, and pushing wavefront-measuring interferometry into the 2-20-nm wavelength range (60-600 eV). These coherent measurement techniques, including lateral shearing interferometry and phase-shifting point-diffraction interferometry (PS/PDI) have achieved RMS wavefront measurement accuracies of 0.5-1-{angstrom} and better for primary aberration terms, enabling the creation of diffraction-limited EUV optics. The measurement accuracy is established using careful null-testing procedures, and has been verified repeatedly through high-resolution imaging. We believe these methods are broadly applicable to the advancement of short-wavelength optical systems including space telescopes, microscope objectives, projection lenses, synchrotron beamline optics, diffractive and holographic optics, and more. Measurements have been performed on a tunable undulator beamline at LBNL's Advanced Light Source (ALS), optimized for high coherent flux; although many of these techniques should be adaptable to alternative ultraviolet, EUV, and soft x-ray light sources. To date, we have measured nine prototype all-reflective EUV optical systems with NA values between 0.08 and 0.30 (f/6.25 to f/1.67). These projection-imaging lenses were created for the semiconductor industry's advanced research in EUV photolithography, a technology slated for introduction in 2009-13. This paper reviews the methods used and our program's accomplishments to date.

  16. Ultra-high accuracy optical testing: creating diffraction-limited short-wavelength optical systems

    International Nuclear Information System (INIS)

    Goldberg, Kenneth A.; Naulleau, Patrick P.; Rekawa, Senajith B.; Denham, Paul E.; Liddle, J. Alexander; Gullikson, Eric M.; Jackson, KeithH.; Anderson, Erik H.; Taylor, John S.; Sommargren, Gary E.; Chapman, Henry N.; Phillion, Donald W.; Johnson, Michael; Barty, Anton; Soufli, Regina; Spiller, Eberhard A.; Walton, Christopher C.; Bajt, Sasa

    2005-01-01

    Since 1993, research in the fabrication of extreme ultraviolet (EUV) optical imaging systems, conducted at Lawrence Berkeley National Laboratory (LBNL) and Lawrence Livermore National Laboratory (LLNL), has produced the highest resolution optical systems ever made. We have pioneered the development of ultra-high-accuracy optical testing and alignment methods, working at extreme ultraviolet wavelengths, and pushing wavefront-measuring interferometry into the 2-20-nm wavelength range (60-600 eV). These coherent measurement techniques, including lateral shearing interferometry and phase-shifting point-diffraction interferometry (PS/PDI) have achieved RMS wavefront measurement accuracies of 0.5-1-(angstrom) and better for primary aberration terms, enabling the creation of diffraction-limited EUV optics. The measurement accuracy is established using careful null-testing procedures, and has been verified repeatedly through high-resolution imaging. We believe these methods are broadly applicable to the advancement of short-wavelength optical systems including space telescopes, microscope objectives, projection lenses, synchrotron beamline optics, diffractive and holographic optics, and more. Measurements have been performed on a tunable undulator beamline at LBNL's Advanced Light Source (ALS), optimized for high coherent flux; although many of these techniques should be adaptable to alternative ultraviolet, EUV, and soft x-ray light sources. To date, we have measured nine prototype all-reflective EUV optical systems with NA values between 0.08 and 0.30 (f/6.25 to f/1.67). These projection-imaging lenses were created for the semiconductor industry's advanced research in EUV photolithography, a technology slated for introduction in 2009-13. This paper reviews the methods used and our program's accomplishments to date

  17. Laser frequency stabilisation by the Pound - Drever - Hall method using an acousto-optic phase modulator operating in the pure Raman - Nath diffraction regime

    International Nuclear Information System (INIS)

    Baryshev, Vyacheslav N

    2012-01-01

    Frequency stabilisation of diode laser radiation has been implemented by the Pound - Drever - Hall method using a new acousto-optic phase modulator, operating in the pure Raman - Nath diffraction regime. It is experimentally shown that, as in the case of saturated-absorption spectroscopy in atomic vapour, the spatial divergence of the frequency-modulated output spectrum of this modulator does not interfere with obtaining error signals by means of heterodyne frequency-modulation spectroscopy with a frequency discriminator based on a high-Q Fabry - Perot cavity with finesse of several tens of thousands.

  18. Experimental issues in in-situ synchrotron x-ray diffraction at high pressure and temperature by using a laser-heated diamond-anvil cell

    International Nuclear Information System (INIS)

    Yoo, C.S.

    1997-01-01

    An integrated technique of diamond-anvil cell, laser-heating and synchrotron x-ray diffraction technologies is capable of structural investigation of condensed matter in an extended region of high pressures and temperatures above 100 GPa and 3000 K. The feasibility of this technique to obtain reliable data, however, strongly depends on several experimental issues, including optical and x-ray setups, thermal gradients, pressure homogeneity, preferred orientation, and chemical reaction. In this paper, we discuss about these experimental issues together with future perspectives of this technique for obtaining accurate data

  19. Laser fusion systems for industrial process heat. Third semiannual report

    International Nuclear Information System (INIS)

    Bates, F.J.; Denning, R.S.; Dykhuizen, R.C.; Goldthwaite, W.H.; Kok, K.D.; Skelton, J.C.

    1979-01-01

    This report concentrates not only on the design of the laser fusion system but also on the cost of this system and the costs of alternative sources of energy that are expected to be in competition with the laser fusion system. The absolute values of the cost of the laser fusion system are limited by the estimates of the cost of the components and subsystems making up the laser fusion energy station. The method used in calculating costs of the laser fusion and alternative systems are laid out in detail

  20. Classifying and assembling two-dimensional X-ray laser diffraction patterns of a single particle to reconstruct the three-dimensional diffraction intensity function: resolution limit due to the quantum noise.

    Science.gov (United States)

    Tokuhisa, Atsushi; Taka, Junichiro; Kono, Hidetoshi; Go, Nobuhiro

    2012-05-01

    A new two-step algorithm is developed for reconstructing the three-dimensional diffraction intensity of a globular biological macromolecule from many experimentally measured quantum-noise-limited two-dimensional X-ray laser diffraction patterns, each for an unknown orientation. The first step is classification of the two-dimensional patterns into groups according to the similarity of direction of the incident X-rays with respect to the molecule and an averaging within each group to reduce the noise. The second step is detection of common intersecting circles between the signal-enhanced two-dimensional patterns to identify their mutual location in the three-dimensional wavenumber space. The newly developed algorithm enables one to detect a signal for classification in noisy experimental photon-count data with as low as ~0.1 photons per effective pixel. The wavenumber of such a limiting pixel determines the attainable structural resolution. From this fact, the resolution limit due to the quantum noise attainable by this new method of analysis as well as two important experimental parameters, the number of two-dimensional patterns to be measured (the load for the detector) and the number of pairs of two-dimensional patterns to be analysed (the load for the computer), are derived as a function of the incident X-ray intensity and quantities characterizing the target molecule. © 2012 International Union of Crystallography

  1. Laser fusion hybrid reactor systems study

    International Nuclear Information System (INIS)

    1976-07-01

    The work was performed in three phases. The first phase included a review of the many possible laser-reactor-blanket combinations and resulted in the selection of a ''demonstration size'' 500 MWe plant for further study. A number of fast fission blankets using uranium metal, uranium-molybdenum alloy, and uranium carbide as fuel were investigated. The second phase included design of the reactor vessel and internals, heat transfer system, tritium processing system, and the balance of plant, excluding the laser building and equipment. A fuel management scheme was developed, safety considerations were reviewed, and capital and operating costs were estimated. Costs developed during the second phase were unexpectedly high, and a thorough review indicated considerable unit cost savings could be obtained by scaling the plant to a larger size. Accordingly, a third phase was added to the original scope, encompassing the redesign and scaling of the plant from 500 MWe to 1200 MWe

  2. Extending the potential of x-ray free-electron lasers to industrial applications—an initiatory attempt at coherent diffractive imaging on car-related nanomaterials

    International Nuclear Information System (INIS)

    Yoshida, Rikiya; Kimura, Takashi; Kuramoto, Mayumi; Yu, Jian; Khakurel, Krishna; Nishino, Yoshinori; Yamashige, Hisao; Miura, Masahide; Joti, Yasumasa; Tono, Kensuke; Yabashi, Makina; Bessho, Yoshitaka; Ishikawa, Tetsuya

    2015-01-01

    Recent advances in x-ray free-electron lasers (XFELs) open up new pathways for contributing to industrial research-and-development activities. In this article, we describe our initiatory attempt at using the SPring-8 Ångström compact free-electron laser (SACLA) for industrial applications. The attempt was conducted by the authors through the industry-academia partnership program initiated by RIKEN, aimed at examining the potential of XFELs for the analysis of car-related nanomaterials. Using the infrastructures developed at SACLA, we performed single-shot coherent diffractive imaging experiments on automotive exhaust catalysts and succeeded in obtaining the reconstructed images. This effort has paved the way for the future use of XFELs in the research-and-development activity of automotive exhaust catalysts. (paper)

  3. Melting of tantalum at high pressure determined by angle dispersive x-ray diffraction in a double-sided laser-heated diamond-anvil cell

    International Nuclear Information System (INIS)

    Errandonea, D; Somayazulu, M; Haeusermann, D; Mao, H K

    2003-01-01

    The high-pressure and high-temperature phase diagram of Ta has been studied in a laser-heated diamond-anvil cell (DAC) using x-ray diffraction measurements up to 52 deg. GPa and 3800 deg. K. The melting was observed at nine different pressures, the melting temperature being in good agreement with previous laser-heated DAC experiments, but in contradiction with several theoretical calculations and previous piston-cylinder apparatus experiments. A small slope for the melting curve of Ta is estimated (dT m /dP ≅ 24 GPa -1 at 1 deg. bar) and a possible explanation for this behaviour is given. Finally, a P-V -T equation of states is obtained, the temperature dependence of the thermal expansion coefficient and the bulk modulus being estimated

  4. Electron-lattice energy relaxation in laser-excited thin-film Au-insulator heterostructures studied by ultrafast MeV electron diffraction.

    Science.gov (United States)

    Sokolowski-Tinten, K; Shen, X; Zheng, Q; Chase, T; Coffee, R; Jerman, M; Li, R K; Ligges, M; Makasyuk, I; Mo, M; Reid, A H; Rethfeld, B; Vecchione, T; Weathersby, S P; Dürr, H A; Wang, X J

    2017-09-01

    We apply time-resolved MeV electron diffraction to study the electron-lattice energy relaxation in thin film Au-insulator heterostructures. Through precise measurements of the transient Debye-Waller-factor, the mean-square atomic displacement is directly determined, which allows to quantitatively follow the temporal evolution of the lattice temperature after short pulse laser excitation. Data obtained over an extended range of laser fluences reveal an increased relaxation rate when the film thickness is reduced or the Au-film is capped with an additional insulator top-layer. This behavior is attributed to a cross-interfacial coupling of excited electrons in the Au film to phonons in the adjacent insulator layer(s). Analysis of the data using the two-temperature-model taking explicitly into account the additional energy loss at the interface(s) allows to deduce the relative strength of the two relaxation channels.

  5. Intergranular stress study of TC11 titanium alloy after laser shock peening by synchrotron-based high-energy X-ray diffraction

    Science.gov (United States)

    Su, R.; Li, L.; Wang, Y. D.; Nie, Z. H.; Ren, Y.; Zhou, X.; Wang, J.

    2018-05-01

    The distribution of residual lattice strain as a function of depth were carefully investigated by synchrotron-based high energy X-ray diffraction (HEXRD) in TC11 titanium alloy after laser shock peening (LSP). The results presented big compressive residual lattice strains at surface and subsurface, then tensile residual lattice strains in deeper region, and finally close to zero lattice strains in further deep interior with no plastic deformation thereafter. These evolutions in residual lattice strains were attributed to the balance of direct load effect from laser shock wave and the derivative restriction force effect from surrounding material. Significant intergranular stress was evidenced in the processed sample. The intergranular stress exhibited the largest value at surface, and rapidly decreased with depth increase. The magnitude of intergranular stress was proportional to the severity of the plastic deformation caused by LSP. Two shocks generated larger intergranular stress than one shock.

  6. Outdoor measurements of a photovoltaic system using diffractive spectrum-splitting and concentration

    Directory of Open Access Journals (Sweden)

    N. Mohammad

    2016-09-01

    Full Text Available In a single-bandgap absorber, photons having energy less than the bandgap are not absorbed, while those having energy larger than the bandgap lose the excess energy via thermalization. We present outdoor measurements of a photovoltaic system that overcomes these losses via spectrum splitting and concentration using a planar diffractive optic. The system was comprised of the diffractive optic coupled with GaInP and CIGS solar cells. The optic provides a geometric concentration of 3X for each solar cell. It is easily fabricated by single-step grayscale lithography and it is ultra-thin with a maximum thickness of only 2.5μm. Electrical measurements under direct sunlight demonstrated an increase of ∼25% in total output power compared to the reference case without spectrum splitting and concentration. Since different bandgaps are in the same plane, the proposed photovoltaic system successfully circumvents the lattice-matching and current-matching issues in conventional tandem multi-junction solar cells. This system is also tolerant to solar spectrum variation and fill-factor degradation of constitutive solar cells.

  7. System for combining laser beams of diverse frequencies

    International Nuclear Information System (INIS)

    1980-01-01

    A system is described for combining laser beams of different frequencies into a number of beams each comprising laser radiation having components of each of the different frequencies. The system can be used in laser isotope separation facilities. (U.K.)

  8. Laser surveillance systems for fuel storage pools

    International Nuclear Information System (INIS)

    Boeck, H.

    1985-06-01

    A Laser Surveillance System (LASSY) as a new safeguards device has been developed under the IAEA research contract No. 3458/RB at the Atominstitut Wien using earlier results by S. Fiarman. This system is designed to act as a sheet of light covering spent fuel assemblies in spent fuel storage pools. When movement of assemblies takes place, LASSY detects and locates the position of the movement in the pool and when interrogated, presents a list of pool positions and times of movement to the safeguards inspector. A complete prototype system was developed and built. Full scale tests showed the principal working capabilities of a LASSY underwater

  9. Laser control of natural disperse systems

    Science.gov (United States)

    Vlasova, Olga L.; Bezrukova, Alexandra G.

    2003-10-01

    Different water disperse systems were studied by integral (spectroturbidemetry) and differential light scattering method with a laser as a source of light. The investigation done concerns the state of kaolin dispersions at storage and under dilution as an example of mineral dispersion systems such as natural water. The role of some light scattering parameters for an optical analysis of water dispersions, like the dispersion of erythrocytes and bacterial cells -Escherichia coli is discussed. The results obtained can help to elaborate the methods for on-line optical control fo natural disperse systems (water, air) with mineral and biological particles.

  10. Mode-Locked Semiconductor Lasers for Optical Communication Systems

    DEFF Research Database (Denmark)

    Yvind, Kresten; Larsson, David; Oxenløwe, Leif Katsuo

    2005-01-01

    We present investigations on 10 and 40 GHz monolithic mode-locked lasers for applications in optical communications systems. New all-active lasers with one to three quantum wells have been designed, fabricated and characterized....

  11. Parallel beam powder diffraction study on the A1C60 system (A=K, Rb)

    International Nuclear Information System (INIS)

    Faigel, G.; Tegze, M.; Bortel, G.; Forro, L.; Oszlanyi, G.; Stephens, P.W.

    1994-01-01

    We report x-ray powder diffraction studies on Rb x C 60 and K x C 60 . It is shown that at room temperature there exist stoichiometric compounds in the Rb x C 60 and K x C 60 systems at the x = 1 composition. Their equilibrium structures are pseudo body centered orthorhombic. The C 60 -C 60 intermolecular separation (9.1 A) is the shortest among the known alkali-fullerides. A first order phase transition is observed at about 380 K from the high temperature fcc phase to the room temperature orthorhombic phase. (orig.)

  12. Laser experimental system as teaching aid for demonstrating basic phenomena of laser feedback

    International Nuclear Information System (INIS)

    Xu, Ling; Zhao, Shijie; Zhang, Shulian

    2015-01-01

    An experimental laser teaching system is developed to demonstrate laser feedback phenomena, which bring great harm to optical communication and benefits to precision measurement. The system consists of an orthogonally polarized He-Ne laser, a feedback mirror which reflects the laser output light into the laser cavity, and an optical attenuator which changes the intensity of the feedback light. As the feedback mirror is driven by a piezoelectric ceramic, the attenuator is adjusted and the feedback mirror is tilted, the system can demonstrate many basic laser feedback phenomena, including weak, moderate and strong optical feedback, multiple feedback and polarization flipping. Demonstrations of these phenomena can give students a better understanding about the intensity and polarization of lasers. The system is well designed and assembled, simple to operate, and provides a valuable teaching aid at an undergraduate level. (paper)

  13. Synchronised laser chaos communication: statistical investigation of an experimental system

    OpenAIRE

    Lawrance, Anthony J.; Papamarkou, Theodore; Uchida, Atsushi

    2017-01-01

    The paper is concerned with analyzing data from an experimental antipodal laser-based chaos shift-keying communication system. Binary messages are embedded in a chaotically behaving laser wave which is transmitted through a fiber-optic cable and are decoded at the receiver using a second laser synchronized with the emitter laser. Instrumentation in the experimental system makes it particularly interesting to be able to empirically analyze both optical noise and synchronization error as well a...

  14. Fiber laser-microscope system for femtosecond photodisruption of biological samples.

    Science.gov (United States)

    Yavaş, Seydi; Erdogan, Mutlu; Gürel, Kutan; Ilday, F Ömer; Eldeniz, Y Burak; Tazebay, Uygar H

    2012-03-01

    We report on the development of a ultrafast fiber laser-microscope system for femtosecond photodisruption of biological targets. A mode-locked Yb-fiber laser oscillator generates few-nJ pulses at 32.7 MHz repetition rate, amplified up to ∼125 nJ at 1030 nm. Following dechirping in a grating compressor, ∼240 fs-long pulses are delivered to the sample through a diffraction-limited microscope, which allows real-time imaging and control. The laser can generate arbitrary pulse patterns, formed by two acousto-optic modulators (AOM) controlled by a custom-developed field-programmable gate array (FPGA) controller. This capability opens the route to fine optimization of the ablation processes and management of thermal effects. Sample position, exposure time and imaging are all computerized. The capability of the system to perform femtosecond photodisruption is demonstrated through experiments on tissue and individual cells.

  15. Neutron diffraction tomography: a unique, 3D inspection technique for crystals using an intensifier TV system

    International Nuclear Information System (INIS)

    Davidson, J.B.; Case, A.L.

    1978-01-01

    The application of phosphor-intensifier-TV techniques to neutron topography and tomography of crystals is described. The older, analogous x-ray topography using wavelengths approximately 1.5A is widely used for surface inspection. However, the crystal must actually be cut in order to see diffraction anomalies beneath the surface. Because 1.5-A thermal neutrons are highly penetrating, much larger and thicker specimens can be used. Also, since neutrons have magnetic moments, they are diffracted by magnetic structures within crystals. In neutron volume topography, the entire crystal or a large part of it is irradiated, and the images obtained are superimposed reflections from the total volume. In neutron tomography (or section topography), a collimated beam irradiates a slice (0.5 to 10 mm) of the crystal. The diffracted image is a tomogram from this part only. A series of tomograms covering the crystal can be taken as the specimen is translated in steps across the narrow beam. Grains, voids, twinning, and other defects from regions down to 1 mm in size can be observed and isolated. Although at present poorer in resolution than the original neutron and film methods, the TV techniques are much faster and, in some cases, permit real-time viewing. Two camera systems are described: a counting camera having a 150 mm 6 Li-ZnS screen for low-intensity reflections which are integrated in a digital memory, and a 300-mm system using analog image storage. Topographs and tomograms of several crystals ranging in size from 4 mm to 80 mm are shown

  16. Lasers in tattoo and pigmentation control: role of the PicoSure(®) laser system.

    Science.gov (United States)

    Torbeck, Richard; Bankowski, Richard; Henize, Sarah; Saedi, Nazanin

    2016-01-01

    The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure(®) laser system (755/532 nm). Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure(®) laser system for tattoo removal. A PubMed search was conducted using the term "picosecond" combined with "laser", "dermatology", and "laser tattoo removal". A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow). Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change. Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure(®) laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments.

  17. High-resolution laser-projection display system using a grating electromechanical system (GEMS)

    Science.gov (United States)

    Brazas, John C.; Kowarz, Marek W.

    2004-01-01

    Eastman Kodak Company has developed a diffractive-MEMS spatial-light modulator for use in printing and display applications, the grating electromechanical system (GEMS). This modulator contains a linear array of pixels capable of high-speed digital operation, high optical contrast, and good efficiency. The device operation is based on deflection of electromechanical ribbons suspended above a silicon substrate by a series of intermediate supports. When electrostatically actuated, the ribbons conform to the supporting substructure to produce a surface-relief phase grating over a wide active region. The device is designed to be binary, switching between a reflective mirror state having suspended ribbons and a diffractive grating state having ribbons in contact with substrate features. Switching times of less than 50 nanoseconds with sub-nanosecond jitter are made possible by reliable contact-mode operation. The GEMS device can be used as a high-speed digital-optical modulator for a laser-projection display system by collecting the diffracted orders and taking advantage of the low jitter. A color channel is created using a linear array of individually addressable GEMS pixels. A two-dimensional image is produced by sweeping the line image of the array, created by the projection optics, across the display screen. Gray levels in the image are formed using pulse-width modulation (PWM). A high-resolution projection display was developed using three 1080-pixel devices illuminated by red, green, and blue laser-color primaries. The result is an HDTV-format display capable of producing stunning still and motion images with very wide color gamut.

  18. Comparison of three different laser systems for application in dentistry

    Science.gov (United States)

    Mindermann, Anja; Niemz, M. H.; Eisenmann, L.; Loesel, Frieder H.; Bille, Josef F.

    1993-12-01

    Three different laser systems have been investigated according to their possible application in dentistry: a free running and a Q-switched microsecond Ho:YAG laser, a free running microsecond Er:YAG laser and picosecond Nd:YLF laser system consisting of an actively mode locked oscillator and a regenerative amplifier. The experiments focused on the question if lasers can support or maybe replace ordinary drilling machines. For this purpose several cavities were generated with the lasers mentioned above. Their depth and quality were judged by light and electron microscopy. The results of the experiments showed that the picosecond Nd:YLF laser system has advantages compared to other lasers regarding their application in dentistry.

  19. Laser-start-up system for magnetic mirror fusion

    International Nuclear Information System (INIS)

    Frank, A.M.; Thomas, S.R.; Denhoy, B.S.; Chargin, A.K.

    1976-01-01

    A CO 2 laser system has been developed at LLL to provide hot start-up plasmas for magnetic mirror fusion experiments. A frozen ammonia pellet is irradiated with a laser power density in excess of 10 13 W/cm 2 in a 50-ns pulse. This system uses commercially available laser systems. Optical components were fabricated both by direct machining and standard techniques. The technologies used in this system are directly applicable to reactor scale systems

  20. A system for time-resolved x-ray diffraction and its application to muscle contraction

    International Nuclear Information System (INIS)

    Amemiya, Yoshiyuki; Hashizume, Hiroo.

    1979-01-01

    A data-collection system has been built which permits time-resolved studies of X-ray diffraction diagrams obtained from contracting muscle on millisecond time scale. The system consists of a linear delay-line position sensitive proportional counter (PSPC), a special data transfer unit and an on-line computer. The PSPC used with a mirror-monochromator camera can detect equatorial reflections from stimulated muscle in a total exposure time of a few seconds. Time-resolved data-collection is achieved by stimulating muscle at a regular time interval, dividing a complete cycle of muscle contraction into many successive time slices and accumulating in computer memory X-ray data for each time slice from many repeated cycles of stimulation. The performances of the system have been demonstrated by recording equatorial reflections from frog skeletal muscle during isometric and isotonic twitch with a time resolution of 25 ms. (author)

  1. Micrometer-scale 3-D shape characterization of eight cements: Particle shape and cement chemistry, and the effect of particle shape on laser diffraction particle size measurement

    International Nuclear Information System (INIS)

    Erdogan, S.T.; Nie, X.; Stutzman, P.E.; Garboczi, E.J.

    2010-01-01

    Eight different portland cements were imaged on a synchrotron beam line at Brookhaven National Laboratory using X-ray microcomputed tomography at a voxel size of about 1 μm per cubic voxel edge. The particles ranged in size roughly between 10 μm and 100 μm. The shape and size of individual particles were computationally analyzed using spherical harmonic analysis. The particle shape difference between cements was small but significant, as judged by several different quantitative shape measures, including the particle length, width, and thickness distributions. It was found that the average shape of cement particles was closely correlated with the volume fraction of C 3 S (alite) and C 2 S (belite) making up the cement powder. It is shown that the non-spherical particle shape of the cements strongly influence laser diffraction results, at least in the sieve size range of 20 μm to 38 μm. Since laser diffraction particle size measurement is being increasingly used by the cement industry, while cement chemistry is always a main factor in cement production, these results could have important implications for how this kind of particle size measurement should be understood and used in the cement industry.

  2. High pressure x-ray diffraction studies on U-Al systems

    International Nuclear Information System (INIS)

    Sahu, P.Ch.; Chandra Shekar, N.V.; Subramanian, N.; Yousuf, Mohammad; Govinda Rajan, K.

    1995-01-01

    In this paper, high pressure x-ray diffraction studies of the three U-Al compounds, namely, UAl 2 , UAl 3 and UAl 4 are presented. The experiments are carried out using a unique diamond anvil high pressure x-ray diffraction system in the Guinier geometry up to a maximum pressure of ∼ 35 GPa. The compressibility behaviour of UAl 2 is consistent with its itinerant 5f states, whereas that of UAl 3 and UAl 4 indicate more towards their localized nature. Among these three compounds, a structural phase transition in UAl 2 has been observed at ∼ 11 GPa and the structure of the high pressure phase has been identified to be of MgNi 2 type with space group P6 3 /mmc. The structure of UAl 2 at NTP is of MgCu 2 type with space group Fd3m. From the electron to atom ratio (e/α) consideration, another structural phase transition, namely, MgNi 2 -MgCu 2 at a higher pressure is proposed. Further, on a similar consideration, a new pressure induced structural sequence, namely, MgCu 2 -MgNi 2 (or MgZn 2 -MgCu 2 ) in the AB 2 type compounds of the f electron based systems is suggested. (author)

  3. The Fiber Optic System for the Advanced Topographic Laser Altimeter System (ATLAS) Instrument

    Science.gov (United States)

    Ott, Melanie N.; Thomes, Joe; Onuma, Eleanya; Switzer, Robert; Chuska, Richard; Blair, Diana; Frese, Erich; Matyseck, Marc

    2016-01-01

    The Advanced Topographic Laser Altimeter System (ATLAS) Instrument has been in integration and testing over the past 18 months in preparation for the Ice, Cloud and Land Elevation Satellite - 2 (ICESat-2) Mission, scheduled to launch in 2017. ICESat-2 is the follow on to ICESat which launched in 2003 and operated until 2009. ATLAS will measure the elevation of ice sheets, glaciers and sea ice or the "cryosphere" (as well as terrain) to provide data for assessing the earth's global climate changes. Where ICESat's instrument, the Geo-Science Laser Altimeter (GLAS) used a single beam measured with a 70 m spot on the ground and a distance between spots of 170 m, ATLAS will measure a spot size of 10 m with a spacing of 70 cm using six beams to measure terrain height changes as small as 4 mm. The ATLAS pulsed transmission system consists of two lasers operating at 532 nm with transmitter optics for beam steering, a diffractive optical element that splits the signal into 6 separate beams, receivers for start pulse detection and a wavelength tracking system. The optical receiver telescope system consists of optics that focus all six beams into optical fibers that feed a filter system that transmits the signal via fiber assemblies to the detectors. Also included on the instrument is a system that calibrates the alignment of the transmitted pulses to the receiver optics for precise signal capture. The larger electro optical subsystems for transmission, calibration, and signal receive, stay aligned and transmitting sufficiently due to the optical fiber system that links them together. The robust design of the fiber optic system, consisting of a variety of multi fiber arrays and simplex assemblies with multiple fiber core sizes and types, will enable the system to maintain consistent critical alignments for the entire life of the mission. Some of the development approaches used to meet the challenging optical system requirements for ATLAS are discussed here.

  4. The fiber optic system for the Advanced Topographic Laser Altimeter System (ATLAS) instrument.

    Science.gov (United States)

    Ott, Melanie N; Thomes, Joe; Onuma, Eleanya; Switzer, Robert; Chuska, Richard; Blair, Diana; Frese, Erich; Matyseck, Marc

    2016-08-28

    The Advanced Topographic Laser Altimeter System (ATLAS) Instrument has been in integration and testing over the past 18 months in preparation for the Ice, Cloud and Land Elevation Satellite - 2 (ICESat-2) Mission, scheduled to launch in 2017. ICESat-2 is the follow on to ICESat which launched in 2003 and operated until 2009. ATLAS will measure the elevation of ice sheets, glaciers and sea ice or the "cryosphere" (as well as terrain) to provide data for assessing the earth's global climate changes. Where ICESat's instrument, the Geo-Science Laser Altimeter (GLAS) used a single beam measured with a 70 m spot on the ground and a distance between spots of 170 m, ATLAS will measure a spot size of 10 m with a spacing of 70 cm using six beams to measure terrain height changes as small as 4 mm.[1] The ATLAS pulsed transmission system consists of two lasers operating at 532 nm with transmitter optics for beam steering, a diffractive optical element that splits the signal into 6 separate beams, receivers for start pulse detection and a wavelength tracking system. The optical receiver telescope system consists of optics that focus all six beams into optical fibers that feed a filter system that transmits the signal via fiber assemblies to the detectors. Also included on the instrument is a system that calibrates the alignment of the transmitted pulses to the receiver optics for precise signal capture. The larger electro optical subsystems for transmission, calibration, and signal receive, stay aligned and transmitting sufficiently due to the optical fiber system that links them together. The robust design of the fiber optic system, consisting of a variety of multi fiber arrays and simplex assemblies with multiple fiber core sizes and types, will enable the system to maintain consistent critical alignments for the entire life of the mission. Some of the development approaches used to meet the challenging optical system requirements for ATLAS are discussed here.

  5. High-power fiber laser with a polarizing diffraction grating milled on the facet of an optical fiber

    Czech Academy of Sciences Publication Activity Database

    Vaněk, Martin; Vaniš, Jan; Baravets, Yauhen; Todorov, Filip; Čtyroký, Jiří; Honzátko, Pavel

    2016-01-01

    Roč. 24, č. 26 (2016), s. 30225-30233 ISSN 1094-4087 R&D Projects: GA ČR GA15-07908S Institutional support: RVO:67985882 Keywords : Optical fibers * Polarization * Diffraction gratings Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.307, year: 2016

  6. High-power fiber laser with a polarizing diffraction grating milled on the facet of an optical fiber

    Czech Academy of Sciences Publication Activity Database

    Vaněk, Martin; Vaniš, Jan; Baravets, Yauhen; Todorov, Filip; Čtyroký, Jiří; Honzátko, Pavel

    2016-01-01

    Roč. 24, č. 26 (2016), s. 30225-30233 ISSN 1094-4087 R&D Projects: GA ČR GA15-07908S Institutional support: RVO:67985882 Keywords : Optical fiber s * Polarization * Diffraction gratings Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 3.307, year: 2016

  7. Laser cutting system in bridge fabricating line; Kyoryo seisaku line ni okeru laser no setsudan system

    Energy Technology Data Exchange (ETDEWEB)

    Kitaguchi, Y.; Yokotani, K. [Hitachi Zosen Corp., Osaka (Japan)

    1994-11-01

    This paper describes the laser cutting system established at a new advanced plant that was constructed by Hitachi Shipbuilding and Engineering Co., Ltd. in 1993. At the plant, the cutting line consists of four NC cutting lines: the plasma cutting machine, gas cutting machine, frame planer, and laser cutting machine. The laser cutting machine is used to cut complex shapes of relatively thin (6 - 16 mm) materials with high accuracy. The machine consists of a 3 kW CO2 laser oscillator mounted gantry type NC cutter and a slat conveyor of about 30 m long, with the maximum cutting width of 3.6 m. The NC cutting machine is provided with the automatic printing function using NC data, marking function, scheduled operation function, steel plate detector, and coordinate rotation function, etc. These functions enable unattended operation of the machine to cut multiple materials. This NC laser cutting line has the same performance data collection function for data during the operating time as other production lines. Therefore, the NC laser cutting line can be subjected to the realtime centralized control together with the other lines. All these technologies have provided high accuracy and efficiency for production as well as an environment in which many female operators can successfully work. 10 figs., 4 tabs.

  8. Diode-laser-illuminated automotive lamp systems

    Science.gov (United States)

    Marinelli, Michael A.; Remillard, Jeffrey T.

    1998-05-01

    We have utilized the high brightness of state-of-the-art diode laser sources, and a variety of emerging optical technologies to develop a new class of thin, uniquely styled automotive brake and signal lamps. Using optics based on thin (5 mm) plastic sheets, these lamps provide appearance and functional advantages not attainable with traditional automotive lighting systems. The light is coupled into the sheets using a 1 mm diameter glass fiber, and manipulated using refraction and reflection from edges, surfaces, and shaped cut-outs. Light can be extracted with an efficiency of approximately 50% and formed into a luminance distribution that meets the Society of Automotive Engineers (SAE) photometric requirements. Prototype lamps using these optics have been constructed and are less than one inch in thickness. Thin lamps reduce sheet metal costs, complexity, material usage, weight, and allow for increased trunk volume. In addition, these optics enhance lamp design flexibility. When the lamps are not energized, they can appear body colored, and when lighted, the brightness distribution across the lamp can be uniform or structured. A diode laser based brake lamp consumes seven times less electrical power than one using an incandescent source and has instant on capability. Also, diode lasers have the potential to be 10-year/150,000 mile light sources.

  9. Long life gas laser system and method

    International Nuclear Information System (INIS)

    Hochuli, E.E.

    1975-01-01

    A long life gas discharge laser having an improved self-repairing cathode system is described. In a specific embodiment, water vapor having a partial pressure below about 10 -5 torr incorporated in a molecular sieve is used to provide impurities (in this case water vapor) for repairing the cathode surface by regenerating the oxide surface and/or preventing same from deteriorating. Other impurities may be incorporated in the molecular sieve such as hydrogen, oxygen, for example. In some cases CO 2 may be used. This application includes material disclosed in a paper entitled ''Continuation of the Investigation into Material Properties Affecting the Frequency Stability and Reliability of He-Ne Laser Structures'' submitted to the Office of Naval Research dated June 1972 by the inventor hereof and also a paper entitled ''Investigations of the Long Term Frequency Stability of Stable Laser Structures'' Progress Report for ONR Contract N00014-67-A-D239-0016 July 1972 by the inventor hereof. A royalty free license is hereby granted to the United States for use of the invention for all government purposes. (auth)

  10. Energy storage and power conditioning system for the Shiva laser

    International Nuclear Information System (INIS)

    Allen, G.R.; Gagnon, W.L.; Rupert, P.R.; Trenholme, J.B.

    1975-01-01

    An optimal energy delivery system for the world's largest glass laser system has been designed based on computer modeling and operation of laser hardware. Components of the system have been tested on operating lasers at LLL. The Shiva system is now under construction and will be completed in 1977. The energy supply described here will provide cost-effective, reliable power and facilitate the gathering of data in pursuit of controlled thermonuclear reactions

  11. Development of AVLIS dye laser system

    International Nuclear Information System (INIS)

    Sugiyama, Akira; Nakayama, Tsuyoshi; Kato, Masaaki; Arisawa, Takashi

    1995-01-01

    CVL pumped single mode dye laser was performed. It was found that pressure tuning has some excellent feature in comparison to mechanical tuning in dye laser frequency control. For evaluation of dye laser amplifier, two-dimensional rate equation was proposed. Calculated data by this equation agreed with experimental data in large diameter input dye laser beam condition. (author)

  12. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: LASER POWER MEASUREMENTS

    Science.gov (United States)

    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 ...

  13. Five years of testing using the simi-automated ultrasonic time of flight diffraction system

    International Nuclear Information System (INIS)

    Webber, S.A.

    2002-01-01

    This paper provides a brief description of the Time of Flight Diffraction (TOFD) test system and also describes a couple of case histories where the system has been successfully applied. The T.O.F.D. system has been contrasted with the conventional manual ultrasonic technique. Whilst the T.O.F.D. system has proven potential, and is without doubt a valuable tool that will continue to gain market share in the inspection industry, conventional manual ultrasonics still has its part to play and will survive for some time to come. One of the outstanding issues facing the T.O.F.D. systems is the question of acceptance testing which is still the predominant convention specified in most standards. Training for a T.O.F.D. system technician is particularly important and the author suggests there are more traps for the unwary than with the conventional manual ultrasonic systems. The overall judgement of the T.O.F.D. system is that it is a most welcome and powerful tool in the hands of the right operator and will do much to boost the prominence of Non-Destructive Testing

  14. Real time neutron diffraction and NMR of the Empress II glass-ceramic system.

    Science.gov (United States)

    O'Donnell, M D; Hill, R G; Karpukhina, N; Law, R V

    2011-10-01

    This study reports real time neutron diffraction on the Empress II glass-ceramic system. The commercial glass-ceramics was characterized by real time neutron diffraction, ³¹P and ²⁹Si solid-state MAS-NMR, DSC and XRD. On heating, the as-received glass ceramic contained lithium disilicate (Li₂Si₂O₅), which melted with increasing temperature. This was revealed by neutron diffraction which showed the Bragg peaks for this phase had disappeared by 958°C in agreement with thermal analysis. On cooling lithium metasilicate (Li₂SiO₃) started to form at around 916°C and a minor phase of cristobalite at around 852°C. The unit cell volume of both Li-silicate phases increased linearly with temperature at a rate of +17×10⁻³ ų.°C⁻¹. Room temperature powder X-ray diffraction (XRD) of the material after cooling confirms presence of the lithium metasilicate and cristobalite as the main phases and shows, in addition, small amount of lithium disilicate and orthophosphate. ³¹P MAS-NMR reveals presence of the lithiorthophosphate (Li₃PO₄) before and after heat treatment. The melting of lithium disilicate on heating and crystallisation of lithium metasilicate on cooling agree with endothermic and exotermic features respectively observed by DSC. ²⁹Si MAS-NMR shows presence of lithium disilicate phase in the as-received glass-ceramic, though not in the major proportion, and lithium metasilicate in the material after heat treatment. Both phases have significantly long T₁ relaxation time, especially the lithium metasilicate, therefore, a quantitative analysis of the ²⁹Si MAS-NMR spectra was not attempted. Significance. The findings of the present work demonstrate importance of the commercially designed processing parameters in order to preserve desired characteristics of the material. Processing the Empress II at a rate slower than recommended 60°C min⁻¹ or long isothermal hold at the maximal processing temperature 920°C can cause

  15. Using a short-pulse diffraction-limited laser beam to probe filamentation of a random phase plate smoothed beam

    International Nuclear Information System (INIS)

    Kline, J. L.; Montgomery, D. S.; Flippo, K. A.; Johnson, R. P.; Rose, H. A.; Shimada, T.; Williams, E. A.

    2008-01-01

    A short pulse (few picoseconds) laser probe provides high temporal resolution measurements to elucidate details of fast dynamic phenomena not observable with typical longer laser pulse probes and gated diagnostics. Such a short pulse laser probe (SPLP) has been used to measure filamentation of a random phase plate (RPP) smoothed laser beam in a gas-jet plasma. The plasma index of refraction due to driven density and temperature fluctuations by the RPP beam perturbs the phase front of a SPLP propagating at a 90 deg. angle with respect to the RPP interaction beam. The density and temperature fluctuations are quasistatic on the time scale of the SPLP (∼2 ps). The transmitted near-field intensity distribution from the SPLP provides a measure of the phase front perturbation. At low plasma densities, the transmitted intensity pattern is asymmetric with striations across the entire probe beam in the direction of the RPP smoothed beam. As the plasma density increases, the striations break up into smaller sizes along the direction of the RPP beam propagation. The breakup of the intensity pattern is consistent with self-focusing of the RPP smoothed interaction beam. Simulations of the experiment using the wave propagation code, PF3D, are in qualitative agreement demonstrating that the asymmetric striations can be attributed to the RPP driven density fluctuations. Quantification of the beam breakup measured by the transmitted SPLP could lead to a new method for measuring self-focusing of lasers in underdense plasmas.

  16. Using a short-pulse diffraction-limited laser beam to probe filamentation of a random phase plate smoothed beam.

    Science.gov (United States)

    Kline, J L; Montgomery, D S; Flippo, K A; Johnson, R P; Rose, H A; Shimada, T; Williams, E A

    2008-10-01

    A short pulse (few picoseconds) laser probe provides high temporal resolution measurements to elucidate details of fast dynamic phenomena not observable with typical longer laser pulse probes and gated diagnostics. Such a short pulse laser probe (SPLP) has been used to measure filamentation of a random phase plate (RPP) smoothed laser beam in a gas-jet plasma. The plasma index of refraction due to driven density and temperature fluctuations by the RPP beam perturbs the phase front of a SPLP propagating at a 90 degree angle with respect to the RPP interaction beam. The density and temperature fluctuations are quasistatic on the time scale of the SPLP (approximately 2 ps). The transmitted near-field intensity distribution from the SPLP provides a measure of the phase front perturbation. At low plasma densities, the transmitted intensity pattern is asymmetric with striations across the entire probe beam in the direction of the RPP smoothed beam. As the plasma density increases, the striations break up into smaller sizes along the direction of the RPP beam propagation. The breakup of the intensity pattern is consistent with self-focusing of the RPP smoothed interaction beam. Simulations of the experiment using the wave propagation code, PF3D, are in qualitative agreement demonstrating that the asymmetric striations can be attributed to the RPP driven density fluctuations. Quantification of the beam breakup measured by the transmitted SPLP could lead to a new method for measuring self-focusing of lasers in underdense plasmas.

  17. Dependence of image quality on energy spread for a Bragg diffraction based radiography system

    International Nuclear Information System (INIS)

    Baldelli, P.; Bacci, A.; Bottigli, U.; Ferrario, M.; Gambaccini, M.; Giulietti, D.; Golosio, B.; Maroli, C.; Oliva, P.; Petrillo, V.; Serafini, L.; Stumbo, S.; Taibi, A.; Tomassini, P.; Vaccarezza, C.

    2007-01-01

    The aim of this work is to investigate the relationship between contrast and energy resolution of a quasi-monochromatic X-ray system based on Bragg diffraction on a mosaic crystal. Three different energies have been considered: 18, 22 and 26 keV. A commercial phantom containing large and small area details and a digital detector have been used. Results show that for large area details and for a certain value of energy, the energy spread of the incident X-ray beams produces a small reduction of the contrast, while for small area details the high reduction of the contrast is principally due to the spatial resolution properties of the system

  18. Recent laser physics results on power balance and frequency conversion with the Phebus laser system

    International Nuclear Information System (INIS)

    Thiell, G.; Paye, J.; Graillot, H.; Mathieu, F.; Boscheron, A.; Reynier, F.; Estraillier, P.; Bruneau, J.L.

    1995-01-01

    The Phebus laser system has been mainly devoted to plasma physics experiments such as implosion and hydrodynamical instability studies since it was completed in 1985. But during the last two years, the three Phebus beamlines (2 main beams and a backlighter beam) are also utilized to perform some laser physics studies in view of the Megajoule laser project. The goal of the laser physics experiments conducted at the Phebus facility in 1994--1995 is to validate some design issues of the Megajoule Laser project concerning namely power balance and frequency conversion

  19. Interferogram reduction and interpretation as applied to the optical analysis of a laser fusion system

    International Nuclear Information System (INIS)

    Viswanathan, V.K.; Sollid, J.E.; Hall, W.S.; Liberman, I.; Lawrence, G.

    1978-01-01

    The 10 kJ Eight-Beam CO 2 Laser Fusion System, currently under construction at Los Alamos Scientific Laboratory (LASL), has approximately 100 optical elements per beam. The nominal system is diffraction limited and degradations in performance are caused primarily by imperfect components and alignment errors. Consequently, analysis and predictions for the system are very much dependent on the proper description of the imperfect components. The approach taken at LASL has been to characterize the components interferometrically. An example of this procedure, using an actual interferogram of a manufactured component, will be presented and the various limitations will be discussed

  20. Lasers and power systems for inertial confinement fusion reactors

    International Nuclear Information System (INIS)

    Stark, E.E. Jr.

    1978-01-01

    After discussing the role of lasers in ICF and the candidate lasers, several important areas of technology requirements are discussed. These include the beam transport system, the pulsed power system and the gas flow system. The system requirements, state of the art, as well as needs and prospects for new technology developments are given. Other technology issues and promising developments are described briefly

  1. Development of YAG laser cutting system for decommissioning nuclear equipments

    International Nuclear Information System (INIS)

    Kasai, Takeshi; Nitta, Kazuhiko; Hosoda, Hiroshi.

    1995-01-01

    Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. As a result, the stainless steel plate with a thickness of 22mm could be cut by using an optical fiber which can flexibly propagate laser power, and possibility of application of this laser cutting system to decommissioning nuclear equipments was verified. (author)

  2. Development of YAG laser cutting system for decommissioning nuclear equipments

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Takeshi [Fuji Electric Co. Research and Development Ltd., Yokosuka, Kanagawa (Japan); Nitta, Kazuhiko; Hosoda, Hiroshi

    1995-07-01

    Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. As a result, the stainless steel plate with a thickness of 22mm could be cut by using an optical fiber which can flexibly propagate laser power, and possibility of application of this laser cutting system to decommissioning nuclear equipments was verified. (author).

  3. 5.5 W near-diffraction-limited power from resonant leaky-wave coupled phase-locked arrays of quantum cascade lasers

    International Nuclear Information System (INIS)

    Kirch, J. D.; Chang, C.-C.; Boyle, C.; Mawst, L. J.; Botez, D.; Lindberg, D.; Earles, T.

    2015-01-01

    Five, 8.36 μm-emitting quantum-cascade lasers (QCLs) have been monolithically phase-locked in the in-phase array mode via resonant leaky-wave coupling. The structure is fabricated by etch and regrowth which provides large index steps (Δn = 0.10) between antiguided-array elements and interelement regions. Such high index contrast photonic-crystal (PC) lasers have more than an order of magnitude higher index contrast than PC-distributed feedback lasers previously used for coherent beam combining in QCLs. Absorption loss to metal layers inserted in the interelement regions provides a wide (∼1.0 μm) range in interelement width over which the resonant in-phase mode is strongly favored to lase. Room-temperature, in-phase-mode operation with ∼2.2 kA/cm 2 threshold-current density is obtained from 105 μm-wide aperture devices. The far-field beam pattern has lobewidths 1.65× diffraction limit (D.L.) and 82% of the light in the main lobe, up to 1.8× threshold. Peak pulsed near-D.L. power of 5.5 W is obtained, with 4.5 W emitted in the main lobe. Means of how to increase the device internal efficiency are discussed

  4. Laser system for a subpicosecond electron linac

    International Nuclear Information System (INIS)

    Crowell, R. A.

    1998-01-01

    At the Argonne Chemistry Division efforts are underway to develop a sub-picosecond electron beam pulse radiolysis facility for chemical studies. The target output of the accelerator is to generate electron pulses that can be adjusted from 3nC in .6ps to 100nC in 45ps. In conjunction with development of the accelerator a state-of-the-art ultrafast laser system is under construction that will drive the linac's photocathode and provide probe pulses that are tunable from the UV to IR spectral regions

  5. Diffractive optical elements for space communication terminals

    OpenAIRE

    Herzig, Hans-Peter; Ehbets, Peter; Teijido, Juan M.; Weible, Kenneth J.; Heimbeck, Hans-Joerg

    2007-01-01

    The potential of diffractive optical elements for advanced laser communication terminals has been investigated. Applications include beam shaping of high- power laser diode arrays, optical filter elements for position detection and hybrid (refractive/diffractive) elements. In addition, we present a design example of a miniaturized terminal including diffractive optics.

  6. The Effects of Slippage and Diffraction in Long-Wavelength Operation of a Free-Electron Laser

    NARCIS (Netherlands)

    Zhulin, V. I.; Haselhoff, E. H.; van Amersfoort, P. W.

    1995-01-01

    The Free-Electron Laser user facility FELIX produces picosecond optical pulses in the wavelength range of 5-110 mu m. The proposed installation of a new undulator with a larger magnetic period would allow extension towards considerably longer wavelengths. This would result in the production of

  7. Cost analysis of lasers for a laser isotope separation system. Final report

    International Nuclear Information System (INIS)

    Mail, R.A.; Markovich, F.J.; Carr, R.H.

    1977-01-01

    To be of practical significance, laser isotope separation (LIS) for separation of 235 U from 238 U must exhibit attributes which make it preferable to expansion of the present facilities. Clearly the most attractive such attribute is the prospect of significant cost reductions, which preliminary studies at LLL suggest will amount to a factor of three and perhaps as much as ten. From these preliminary studies, it appears that the lasers themselves account for a very substantial portion of the capital cost of a LIS system, and a significant portion of the equipment replacement costs. Since the laser costs are so pivotal to the system cost, and the system cost is so pivotal to the choice of separation techniques, it is clear that a more detailed investigation of laser costs is required. Results are presented of a study performed by General Research Corporation (GRC) to assess the cost of lasers in a production laser isotope separation (LIS) plant

  8. High power laser downhole cutting tools and systems

    Science.gov (United States)

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

    2015-01-20

    Downhole cutting systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser cutting operations within a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform cutting operations in such boreholes deep within the earth.

  9. Micromanipulation and pick-up system for X-Ray diffraction characterization of micrometer-sized single particles

    International Nuclear Information System (INIS)

    Takeichi, Y; Inami, N; Saito, K; Otori, H; Sagayama, R; Kumai, R; Ono, K; Ueno, T

    2014-01-01

    We describe a micromanipulation and pick-up system for preparing a micrometer-sized single particle for X-ray diffraction characterization. Combining a microgripper based on microelectromechanical systems, piezo-motor-driven linear stages, and a gamepad, the system provides precise and intuitive handling of the object. Single-crystal X-ray diffraction measurements of Sm-Fe-N permanent magnet were performed using this system. We also describe a method to distinguish crystallographically homogeneous particles found in powder-form samples.

  10. Stability design considerations for mirror support systems in ICF lasers

    International Nuclear Information System (INIS)

    Tietbohl, G.L.; Sommer, S.C.

    1996-10-01

    Some of the major components of laser systems used for Inertial Confinement Fusion (ICF) are the large aperture mirrors which direct the path of the laser. These mirrors are typically supported by systems which consist of mirror mounts, mirror enclosures, superstructures, and foundations. Stability design considerations for the support systems of large aperture mirrors have been developed based on the experience of designing and evaluating similar systems at the Lawrence Livermore National Laboratory (LLNL). Examples of the systems developed at LLNL include Nova, the Petawatt laser, Beamlet, and the National Ignition Facility (NIF). The structural design of support systems of large aperture mirrors has typically been controlled by stability considerations in order for the large laser system to meet its performance requirements for alignment and positioning. This paper will discuss the influence of stability considerations and will provide guidance on the structural design and evaluation of mirror support systems in ICF lasers so that this information can be used on similar systems

  11. State of the art of CO laser angioplasty system

    Science.gov (United States)

    Arai, Tsunenori; Mizuno, Kyoichi; Miyamoto, Akira; Sakurada, Masami; Kikuchi, Makoto; Kurita, Akira; Nakamura, Haruo; Takaoka, Hidetsugu; Utsumi, Atsushi; Takeuchi, Kiyoshi

    1994-07-01

    A unique percutaneous transluminal coronary angioplasty system new IR therapy laser with IR glass fiber delivery under novel angioscope guidance was described. Carbon monoxide (CO) laser emission of 5 mm in wavelength was employed as therapy laser to achieve precise ablation of atheromatous plaque with a flexible As-S IR glass fiber for laser delivery. We developed the first medical CO laser as well as As-S IR glass fiber cable. We also developed 5.5 Fr. thin angioscope catheter with complete directional manipulatability at its tip. The system control unit could manage to prevent failure irradiations and fiber damages. This novel angioplasty system was evaluated by a stenosis model of mongrel dogs. We demonstrated the usefulness of our system to overcome current issues on laser angioplasty using multifiber catheter with over-the-guidewire system.

  12. Fluorescence-pumped photolytic gas laser system for a commercial laser fusion power plant

    International Nuclear Information System (INIS)

    Monsler, M.J.

    1977-01-01

    The first results are given for the conceptual design of a short-wavelength gas laser system suitable for use as a driver (high average power ignition source) for a commercial laser fusion power plant. A comparison of projected overall system efficiencies of photolytically excited oxygen, sulfur, selenium and iodine lasers is described, using a unique windowless laser cavity geometry which will allow scaling of single amplifier modules to 125 kJ per aperture for 1 ns pulses. On the basis of highest projected overall efficiency, a selenium laser is chosen for a conceptual power plant fusion laser system. This laser operates on the 489 nm transauroral transition of selenium, excited by photolytic dissociation of COSe by ultraviolet fluorescence radiation. Power balances and relative costs for optics, electrical power conditioning and flow conditioning of both the laser and fluorescer gas streams are discussed for a system with the following characteristics: 8 operating modules, 2 standby modules, 125 kJ per module, 1.4 pulses per second, 1.4 MW total average power. The technical issues of scaling visible and near-infrared photolytic gas laser systems to this size are discussed

  13. A novel diode laser system for photodynamic therapy

    DEFF Research Database (Denmark)

    Samsøe, E.; Andersen, P. E.; Petersen, P.

    2001-01-01

    In this paper a novel diode laser system for photodynamic therapy is demonstrated. The system is based on linear spatial filtering and optical phase conjugate feedback from a photorefractive BaTiO3 crystal. The spatial coherence properties of the diode laser are significantly improved. The system...

  14. Diffractive interactions

    International Nuclear Information System (INIS)

    Del Duca, V.; Marage, P.

    1996-08-01

    The general framework of diffractive deep inelastic scattering is introduced and reports given in the session on diffractive interactions at the international workshop on deep-inelastic scattering and related phenomena, Rome, April 1996, are presented. (orig.)

  15. Lasers in tattoo and pigmentation control: role of the PicoSure® laser system

    Directory of Open Access Journals (Sweden)

    Torbeck R

    2016-05-01

    Full Text Available Richard Torbeck,1 Richard Bankowski,2 Sarah Henize,3 Nazanin Saedi,11Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 2Cynosure, Inc, Westford, MA, 3Huron Consulting Group, Chicago, IL, USABackground and objectives: The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure® laser system (755/532 nm. Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure® laser system for tattoo removal.Study design and methods: A PubMed search was conducted using the term "picosecond" combined with "laser", "dermatology", and "laser tattoo removal".Results: A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow. Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change.Conclusion: Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure® laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments.Keywords: tattoo, removal, laser, picosecond 

  16. Adaptive High Frequency Laser Sonar System

    National Research Council Canada - National Science Library

    Cray, Benjamin A

    2007-01-01

    .... Antivibration mounts are joined between said scanning laser vibrometer and said housing. In further embodiments, the scanning laser vibrometer detects vibrations at a plurality of locations on the acoustic window forming a virtual array...

  17. Applications of anomalous diffraction systems, generation of attosecond electron and photon pulses and Raman amplification by stimulated emission of radiation

    Science.gov (United States)

    Vartak, Sameer Dinkar

    1998-10-01

    Anomalous diffraction is scattering process due to phase distortion introduced on incident phase front by scattering object. Phase mask or hologram, Christiansen filter, PDLC are examples of an anomalously diffracting systems. Phase hologram modulates an input wavefront to produce a wavefront which when Fourier transformed using a converging lens gives desired image on to a screen. We made a nonlinear optical element using phase mask made up of nonlinear material. It forms a lens because of nonlinear index of refraction when a high intensity beam is incident. This lens Fourier transforms the phase mask and images the phase mask. This nonlinear optical element can be used for various applications like image gating and 3-D memory writing and read out. Christiansen filter (CF) is a two component scattering system whose dispersion curves intersect at certain wavelength. Thus light corresponding to this wavelength traverses the filter without any scattering and light at other wavelengths gets scattered. This results in narrow wavelength dependent transmission curve centered at the index matching wavelength. When materials with an intensity dependent refractive index are used to make a CF, the index matching condition of CF becomes function of the input intensity resulting in intensity dependent beam size and transmittance through the filter. This property of nonlinear CF can be used to switch beam optically in both self and cross-modulation modes. Polymer Dispersed Liquid Crystal (PDLC) is dispersion of liquid crystal droplets in polymer whose index of refraction is same as ordinary refractive index of liquid crystal. PDLC shows voltage dependent scattering and are used in flat panel displays. We used this element as voltage controlled intracavity loss element in a laser cavity to make a lasing pixel projection display. Output of this pixel shows all desired properties for a projection display like narrow linewidth, high brightness, TTL switching compatibility and

  18. Feedback stabilization system for pulsed single longitudinal mode tunable lasers

    Science.gov (United States)

    Esherick, Peter; Raymond, Thomas D.

    1991-10-01

    A feedback stabilization system for pulse single longitudinal mode tunable lasers having an excited laser medium contained within an adjustable length cavity and producing a laser beam through the use of an internal dispersive element, including detection of angular deviation in the output laser beam resulting from detuning between the cavity mode frequency and the passband of the internal dispersive element, and generating an error signal based thereon. The error signal can be integrated and amplified and then applied as a correcting signal to a piezoelectric transducer mounted on a mirror of the laser cavity for controlling the cavity length.

  19. Optical laser systems at the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Minitti, Michael P.; Robinson, Joseph S.; Coffee, Ryan N.; Edstrom, Steve; Gilevich, Sasha; Glownia, James M.; Granados, Eduardo; Hering, Philippe; Hoffmann, Matthias C.; Miahnahri, Alan; Milathianaki, Despina; Polzin, Wayne; Ratner, Daniel; Tavella, Franz; Vetter, Sharon; Welch, Marc; White, William E.; Fry, Alan R., E-mail: alanfry@slac.stanford.edu [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2015-04-22

    This manuscript serves as a reference to describe the optical laser sources and capabilities at the Linac Coherent Light Source. Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump–probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump–probe experiments to be performed at LCLS.

  20. Classification of projection images of proteins with structural polymorphism by manifold: A simulation study for x-ray free-electron laser diffraction imaging

    Science.gov (United States)

    Yoshidome, Takashi; Oroguchi, Tomotaka; Nakasako, Masayoshi; Ikeguchi, Mitsunori

    2015-09-01

    Coherent x-ray diffraction imaging (CXDI) enables us to visualize noncrystalline sample particles with micrometer to submicrometer dimensions. Using x-ray free-electron laser (XFEL) sources, two-dimensional diffraction patterns are collected from fresh samples supplied to the irradiation area in the "diffraction-before-destruction" scheme. A recent significant increase in the intensity of the XFEL pulse is promising and will allow us to visualize the three-dimensional structures of proteins using XFEL-CXDI in the future. For the protocol proposed for molecular structure determination using future XFEL-CXDI [T. Oroguchi and M. Nakasako, Phys. Rev. E 87, 022712 (2013), 10.1103/PhysRevE.87.022712], we require an algorithm that can classify the data in accordance with the structural polymorphism of proteins arising from their conformational dynamics. However, most of the algorithms proposed primarily require the numbers of conformational classes, and then the results are biased by the numbers. To improve this point, here we examine whether a method based on the manifold concept can classify simulated XFEL-CXDI data with respect to the structural polymorphism of a protein that predominantly adopts two states. After random sampling of the conformations of the two states and in-between states from the trajectories of molecular dynamics simulations, a diffraction pattern is calculated from each conformation. Classification was performed by using our custom-made program suite named enma, in which the diffusion map (DM) method developed based on the manifold concept was implemented. We successfully classify most of the projection electron density maps phase retrieved from diffraction patterns into each of the two states and in-between conformations without the knowledge of the number of conformational classes. We also examined the classification of the projection electron density maps of each of the three states with respect to the Euler angle. The present results suggest

  1. Atomic iodine laser

    International Nuclear Information System (INIS)

    Fisk, G.A.; Gusinow, M.A.; Hays, A.K.; Padrick, T.D.; Palmer, R.E.; Rice, J.K.; Truby, F.K.; Riley, M.E.

    1978-05-01

    The atomic iodine photodissociation laser has been under intensive study for a number of years. The physics associated with this system is now well understood and it is possible to produce a 0.1 nsec (or longer) near-diffraction-limited laser pulse which can be amplified with negligible temporal distortion and little spatial deformation. The output of either a saturated or unsaturated amplifier consists of a high-fidelity near-diffraction-limited, energetic laser pulse. The report is divided into three chapters. Chapter 1 is a survey of the important areas affecting efficient laser operation and summarizes the findings of Chap. 2. Chapter 2 presents detailed discussions and evaluations pertinent to pumps, chemical regeneration, and other elements in the overall laser system. Chapter 3 briefly discusses those areas that require further work and the nature of the work required to complete the full-scale evaluation of the applicability of the iodine photodissociation laser to the inertial confinement program

  2. Diffraction theory

    NARCIS (Netherlands)

    Bouwkamp, C.J.

    1954-01-01

    A critical review is presented of recent progress in classical diffraction theory. Both scalar and electromagnetic problems are discussed. The report may serve as an introduction to general diffraction theory although the main emphasis is on diffraction by plane obstacles. Various modifications of

  3. METHOD AND SYSTEM FOR LASER WELDING

    DEFF Research Database (Denmark)

    2008-01-01

    The invention relates to laser welding of at least two adjacent, abutting or overlapping work pieces in a welding direction using multiple laser beams guided to a welding region, wherein at least two of the multiple laser beams are coupled into the welding region so as to form a melt and at least...

  4. Laser-GMA Hybrid Pipe Welding System

    Science.gov (United States)

    2007-11-01

    Investigation of varying laser power. The welded pipe is shown, with close -ups of the rootside reinforcement and macro sections...68 Figure 44. Investigation of varying laser stand-off. The welded pipe is shown, along with close -ups of backside...conventional beveled joints. With appropriate joint configuration and preparation, deep keyhole penetration provided by the laser and additional filler

  5. Chaotic dynamics and chaos control in nonlinear laser systems

    International Nuclear Information System (INIS)

    Fang Jinqing; Yao Weiguang

    2001-01-01

    Chaotic dynamics and chaos control have become a great challenge in nonlinear laser systems and its advances are reviewed mainly based on the ring cavity laser systems. The principle and stability conditions for time-delay feedback control are analyzed and applied to chaos control in the laser systems. Other advanced methods of chaos control, such as weak spatial perturbation and occasional proportional feedback technique, are discussed. Prospects of chaos control for application (such as improvement of laser power and performance, synchronized chaos secure communication and information processing) are pointed out finally

  6. Development of the power control system for semiconductor lasers

    International Nuclear Information System (INIS)

    Kim, Kwang Suk; Kim, Cheol Jung

    1997-12-01

    For the first year plan of this program, we developed the power control system for semiconductor lasers. We applied the high-current switching mode techniques to fabricating a power control system. Then, we investigated the direct side pumping techniques with GaA1As diode laser bars to laser crystal without pumping optics. We obtained 0.5W average output power from this DPSSL. (author). 54 refs., 3 tabs., 18 figs

  7. Modematic: a fast laser beam analyzing system for high power CO2-laser beams

    Science.gov (United States)

    Olsen, Flemming O.; Ulrich, Dan

    2003-03-01

    The performance of an industrial laser is very much depending upon the characteristics of the laser beam. The ISO standards 11146 and 11154 describing test methods for laser beam parameters have been approved. To implement these methods in industry is difficult and especially for the infrared laser sources, such as the CO2-laser, the availabl analyzing systems are slow, difficult to apply and having limited reliability due to the nature of the detection methods. In an EUREKA-project the goal was defined to develop a laser beam analyzing system dedicated to high power CO2-lasers, which could fulfill the demands for an entire analyzing system, automating the time consuming pre-alignment and beam conditioning work required before a beam mode analyses, automating the analyzing sequences and data analysis required to determine the laser beam caustics and last but not least to deliver reliable close to real time data to the operator. The results of this project work will be described in this paper. The research project has led to the development of the Modematic laser beam analyzer, which is ready for the market.

  8. High-power green diode laser systems for biomedical applications

    DEFF Research Database (Denmark)

    Müller, André

    propagation parameters and therefore efficiently increases the brightness of compact and cost-effective diode laser systems. The condition of overlapping beams is an ideal scenario for subsequent frequency conversion. Based on sum-frequency generation of two beam combined diode lasers a 3.2 fold increase...... output power of frequency doubled single emitters is limited by thermal effects potentially resulting in laser degradation and failure. In this work new concepts for power scaling of visible diode laser systems are introduced that help to overcome current limitations and enhance the application potential....... Implementing the developed concept of frequency converted, beam combined diode laser systems will help to overcome the high pump thresholds for ultrabroad bandwidth titanium sapphire lasers, leading towards diode based high-resolution optical coherence tomography with enhanced image quality. In their entirety...

  9. New laser system for highly sensitive clinical pulse oximetry

    Science.gov (United States)

    Hamza, Mostafa; Hamza, Mohammad

    1996-04-01

    This paper describes the theory and design of a new pulse oximeter in which laser diodes and other compact laser sources are used for the measurement of oxygen saturation in patients who are at risk of developing hypoxemia. The technique depends upon illuminating special sites of the skin of the patient with radiation from modulated laser sources at selected wavelengths. The specific laser wavelengths are chosen based on the absorption characteristics of oxyhemoglobin, reduced hemoglobin and other interfering sources for obtaining more accurate measurements. The laser radiation transmitted through the tissue is detected and signal processing based on differential absorption laser spectroscopy is done in such a way to overcome the primary performance limitations of the conventionally used pulse oximetry. The new laser pulse oximeter can detect weak signals and is not affected by other light sources such as surgical lamps, phototherapy units, etc. The detailed description and operating characteristics of this system are presented.

  10. Development of portable laser peening systems for nuclear power reactors

    International Nuclear Information System (INIS)

    Chida, Itaru; Uehara, Takuya; Yoda, Masaki; Miyasaka, Hiroyuki; Kato, Hiromi

    2009-01-01

    Stress corrosion cracking (SCC) is the major factor to reduce the reliability of aged reactor components. Toshiba has developed various laser-based maintenance and repair technologies and applied them to existing nuclear power plants. Laser-based technology is considered to be the best tool for remote processing in nuclear power plants, and particularly so for the maintenance and repair of reactor core components. Accessibility could be drastically improved by a simple handling system owing to the absence of reactive force against laser irradiation and the flexible optical fiber. For the preventive maintenance, laser peening technology was developed and applied to reactor components in operating BWRs and PWRs. Laser peening is a novel process to improve residual stress from tensile to compressive on material surface layer by irradiating focused high-power laser pulses in water without any surface preparations. Laser peening systems, which deliver laser pulses with mirrors or through an optical fiber, were developed and have been applied to preventive maintenance against SCC in nuclear power reactors since 1999. Each system was composed of laser oscillators, a beam delivery system, a laser irradiation head, remote handling equipment and a monitor/control system. Beam delivery with mirrors was accomplished through alignment/tracking functions with sufficient accuracy. Reliable fiber-delivery was attained by the development of a novel input coupling optics and an irradiation head with auto-focusing. Recently, we have developed portable laser peening (PLP) system which could employ both mirror- and fiber- delivery technologies. Size and weight of the PLP system for BWR bottom was almost 1/25 compared to the previous system. PLP system would be the applicable to both BWRs and PWRs as one of the maintenance technologies. (author)

  11. Time-resolved X-ray diffraction studies of laser-induced acoustic wave propagation in bilayer metallic thin crystals

    Energy Technology Data Exchange (ETDEWEB)

    Er, Ali Oguz [Department of Physics and Astronomy, Western Kentucky University, Bowling Green, Kentucky 42101 (United States); Tang, Jau, E-mail: jautang@gate.sinica.edu.tw, E-mail: prentzepis@ece.tamu.edu [Research Center for Applied Sciences Academia Sinica, Taipei, Taiwan (China); Chen, Jie [Key Laboratory for Laser Plasmas (Ministry of Education) and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Rentzepis, Peter M., E-mail: jautang@gate.sinica.edu.tw, E-mail: prentzepis@ece.tamu.edu [Department of Electrical and Computer Engineering, Texas A and M University, College Station, Texas 77843 (United States)

    2014-09-07

    Phonon propagation across the interface of a Cu/Ag(111) bilayer and transient lattice disorder, induced by a femtosecond 267 nm pulse, in Ag(111) crystal have been measured by means of time resolved X-ray diffraction. A “blast” force due to thermal stress induced by suddenly heated electrons is formed within two picoseconds after excitation and its “blast wave” propagation through the interface and Ag (111) crystal was monitored by the shift and broadening of the rocking curve, I vs. ω, as a function of time after excitation. Lattice disorder, contraction and expansion as well as thermal strain formation and wave propagation have also been measured. The experimental data and mechanism proposed are supported by theoretical simulations.

  12. Exact solution for the reflection and diffraction of atomic de Broglie waves by a travelling evanescent laser wave

    International Nuclear Information System (INIS)

    Witte, N.S.

    1997-01-01

    The exact solution to the problem of reflection and diffraction of atomic de Broglie waves by a travelling evanescent wave is found starting with a bare-state formulation. The solution for the wavefunctions, the tunnelling losses and the non-adiabatic losses are given exactly in terms of hyper-Bessel functions, and are valid for all detuning and Rabi frequencies, thus generalizing previous approximate methods. Furthermore we give the limiting cases of all amplitudes in the uniform semiclassical limit, which is valid in all regions including near the classical turning points, and in the large and weak coupling cases. Exact results for the zero detuning case are obtained in terms of Bessel functions. We find our uniform semiclassical limit to be closer to the exact result over the full range of parameter values than the previously reported calculations. The current knowledge of hyper-Bessel function properties is reviewed in order to apply this to the physical problems imposed

  13. Mercury: The Los Alamos ICF KrF laser system

    International Nuclear Information System (INIS)

    Czuchlewski, S.J.; York, G.W.; Bigio, I.J.; Brucker, J.; Hanson, D.; Honig, E.M.; Kurnit, N.; Leland, W.; McCown, A.W.; McLeod, J.; Rose, E.; Thomas, S.; Thompson, D.

    1993-01-01

    The Mercury KrF laser facility at Los Alamos is being built with the benefit of lessons learned from the Aurora system. An increased understanding of KrF laser engineering, and the designed implementation of system flexibility, will permit Mercury to serve as a tested for a variety of advanced KrF technology concepts

  14. Solid-state disk amplifiers for fusion-laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Martin, W.E.; Trenholme, J.B.; Linford, G.J.; Yarema, S.M.; Hurley, C.A.

    1981-09-01

    We review the design, performance, and operation of large-aperture (10 to 46 cm) solid-state disk amplifiers for use in laser systems. We present design data, prototype tests, simulations, and projections for conventional cylindrical pump-geometry amplifiers and rectangular pump-geometry disk amplifiers. The design of amplifiers for the Nova laser system is discussed.

  15. Mechanical design for a large fusion laser system

    International Nuclear Information System (INIS)

    Hurley, C.A.

    1979-01-01

    The Nova Mechanical Systems Group at LLL is responsible for the design, fabrication, and installation of all laser chain components, for the stable support structure that holds them, and for the beam lines that transport the laser beam to the target system. This paper is an overview of the group's engineering effort, emphasizing new developments

  16. Pulse propagation properties in high-power CO2 laser system for laser fusion

    International Nuclear Information System (INIS)

    Daido, H.; Inoue, M.; Fujita, H.; Matoba, M.; Nakai, S.

    1981-01-01

    The simulation results of nonlinear propagation properties in the CO 2 laser system using a simulation model of the SF 6 saturable absorbers and the CO 2 laser amplifiers agree well with the experimental results. The technical problems of the simultaneous irradiation of the multi-beams to a target are also discussed. (author)

  17. Research on laser cladding control system based on fuzzy PID

    Science.gov (United States)

    Zhang, Chuanwei; Yu, Zhengyang

    2017-12-01

    Laser cladding technology has a high demand for control system, and the domestic laser cladding control system mostly uses the traditional PID control algorithm. Therefore, the laser cladding control system has a lot of room for improvement. This feature is suitable for laser cladding technology, Based on fuzzy PID three closed-loop control system, and compared with the conventional PID; At the same time, the laser cladding experiment and friction and wear experiment were carried out under the premise of ensuring the reasonable control system. Experiments show that compared with the conventional PID algorithm in fuzzy the PID algorithm under the surface of the cladding layer is more smooth, the surface roughness increases, and the wear resistance of the cladding layer is also enhanced.

  18. Analysis of the diffraction peaks in the ZrCr2 system

    International Nuclear Information System (INIS)

    Quiroga, A.A.; Esquivel, M.R.

    2009-01-01

    In this work, the crystalline structures of Cr and Zr are characterized by X-ray Diffraction (XRD). The diffraction peaks are simulated using a numerical convolution of the Gauss and Lorentz functions. The simulation of the model is verified using empirical measurements of the diffraction peaks. From these results, the microstructure parameters of Zr and Cr are obtained: crystallite size (d) and strain (s). The advances obtained are used in the design of the synthesis of AB 2 intermetallics applied to thermal compression of hydrogen (Tch). (author)

  19. Theory of time-resolved inelastic x-ray diffraction

    DEFF Research Database (Denmark)

    Lorenz, Ulf; Møller, Klaus Braagaard; Henriksen, Niels Engholm

    2010-01-01

    Starting from a general theory of time-resolved x-ray scattering, we derive a convenient expression for the diffraction signal based on a careful analysis of the relevant inelastic scattering processes. We demonstrate that the resulting inelastic limit applies to a wider variety of experimental...... conditions than similar, previously derived formulas, and it directly allows the application of selection rules when interpreting diffraction signals. Furthermore, we present a simple extension to systems simultaneously illuminated by x rays and a laser beam....

  20. High-Voltage Power Supply System for Laser Isotope Separation

    Energy Technology Data Exchange (ETDEWEB)

    Ketaily, E.C.; Buckner, R.P.; Uhrik, R.L.

    1979-06-26

    This report presents several concepts for Laser High-Voltage Power Supply (HVPS) Systems for a Laser Isotope Separation facility. Selection of equipments and their arrangement into operational systems is based on proven designs and on application concepts now being developed. This report has identified a number of alternative system arrangements and has provided preliminary cost estimates for each. The report includes a recommendation for follow-on studies that will further define the optimum Laser HVPS Systems. Brief descriptions are given of Modulator/Regulator circuit trade-offs, system control interfaces, and their impact on costs.

  1. High-Voltage Power Supply System for Laser Isotope Separation

    International Nuclear Information System (INIS)

    Ketaily, E.C.; Buckner, R.P.; Uhrik, R.L.

    1979-01-01

    This report presents several concepts for Laser High-Voltage Power Supply (HVPS) Systems for a Laser Isotope Separation facility. Selection of equipments and their arrangement into operational systems is based on proven designs and on application concepts now being developed. This report has identified a number of alternative system arrangements and has provided preliminary cost estimates for each. The report includes a recommendation for follow-on studies that will further define the optimum Laser HVPS Systems. Brief descriptions are given of Modulator/Regulator circuit trade-offs, system control interfaces, and their impact on costs

  2. Lasers in tattoo and pigmentation control: role of the PicoSure® laser system

    Science.gov (United States)

    Torbeck, Richard; Bankowski, Richard; Henize, Sarah; Saedi, Nazanin

    2016-01-01

    Background and objectives The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure® laser system (755/532 nm). Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure® laser system for tattoo removal. Study design and methods A PubMed search was conducted using the term “picosecond” combined with “laser”, “dermatology”, and “laser tattoo removal”. Results A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow). Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change. Conclusion Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure® laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments. PMID:27194919

  3. High Average Power, High Energy Short Pulse Fiber Laser System

    Energy Technology Data Exchange (ETDEWEB)

    Messerly, M J

    2007-11-13

    Recently continuous wave fiber laser systems with output powers in excess of 500W with good beam quality have been demonstrated [1]. High energy, ultrafast, chirped pulsed fiber laser systems have achieved record output energies of 1mJ [2]. However, these high-energy systems have not been scaled beyond a few watts of average output power. Fiber laser systems are attractive for many applications because they offer the promise of high efficiency, compact, robust systems that are turn key. Applications such as cutting, drilling and materials processing, front end systems for high energy pulsed lasers (such as petawatts) and laser based sources of high spatial coherence, high flux x-rays all require high energy short pulses and two of the three of these applications also require high average power. The challenge in creating a high energy chirped pulse fiber laser system is to find a way to scale the output energy while avoiding nonlinear effects and maintaining good beam quality in the amplifier fiber. To this end, our 3-year LDRD program sought to demonstrate a high energy, high average power fiber laser system. This work included exploring designs of large mode area optical fiber amplifiers for high energy systems as well as understanding the issues associated chirped pulse amplification in optical fiber amplifier systems.

  4. Investigations of a Dual Seeded 1178 nm Raman Laser System

    Science.gov (United States)

    2016-01-14

    was obtained by Raman amplification of a distributed feedback diode laser in a variably strained polarization- maintaining fiber with a record-high...Calia, D.B., “50W CW visible laser source at 589 nm obtained via frequency doubling of three coherently combined narrow-band Raman fiber amplifiers...AFRL-RD-PS- TP-2016-0009 AFRL-RD-PS- TP-2016-0009 INVESTIGATIONS OF A DUAL SEEDED 1178 NM RAMAN LASER SYSTEM Leanne Henry, et al. 14 January

  5. Thermally induced diffraction losses for a Gaussian pump beam and optimization of the mode-to-pump ratio in an end-pumped Nd:GdVO4 laser

    International Nuclear Information System (INIS)

    Wang, Y T; Li, W J; Pan, L L; Yu, J T; Zhang, R H

    2013-01-01

    The analytical model of thermally induced diffraction losses for a Gaussian pump beam are derived as functions of the mode-to-pump ratio and pump power in end-pumped Nd-doped lasers considering the energy transfer upconversion effects. The mode-to-pump ratio is optimized based on it. The results show that the optimum mode-to-pump ratio with the thermally induced diffraction losses is less than 0.65, and it is less than the results in which the thermally induced diffraction losses are neglected. The theoretical model is applied to a diode-end-pumped Nd:GdVO 4 laser operating at 1342 nm, and the theoretical calculations are in good agreement with the experimental results. (paper)

  6. A control system for a free electron laser experiment

    International Nuclear Information System (INIS)

    Giove, D.

    1992-01-01

    The general layout of a control and data acquisition system for a Free Electron Laser experiment will be discussed. Some general considerations about the requirements and the architecture of the whole system will be developed. (author)

  7. High power radiation guiding systems for laser driven accelerators

    International Nuclear Information System (INIS)

    Cutolo, A.

    1985-01-01

    This paper reviews the main problems encountered in the design of an optical system for transmitting high fluence radiation in a laser driven accelerator. Particular attention is devoted to the analysis of mirror and waveguide systems. (orig.)

  8. Accelerated Synchrotron X-ray Diffraction Data Analysis on a Heterogeneous High Performance Computing System

    Energy Technology Data Exchange (ETDEWEB)

    Qin, J; Bauer, M A, E-mail: qin.jinhui@gmail.com, E-mail: bauer@uwo.ca [Computer Science Department, University of Western Ontario, London, ON N6A 5B7 (Canada)

    2010-11-01

    The analysis of synchrotron X-ray Diffraction (XRD) data has been used by scientists and engineers to understand and predict properties of materials. However, the large volume of XRD image data and the intensive computations involved in the data analysis makes it hard for researchers to quickly reach any conclusions about the images from an experiment when using conventional XRD data analysis software. Synchrotron time is valuable and delays in XRD data analysis can impact decisions about subsequent experiments or about materials that they are investigating. In order to improve the data analysis performance, ideally to achieve near real time data analysis during an XRD experiment, we designed and implemented software for accelerated XRD data analysis. The software has been developed for a heterogeneous high performance computing (HPC) system, comprised of IBM PowerXCell 8i processors and Intel quad-core Xeon processors. This paper describes the software and reports on the improved performance. The results indicate that it is possible for XRD data to be analyzed at the rate it is being produced.

  9. Accelerated Synchrotron X-ray Diffraction Data Analysis on a Heterogeneous High Performance Computing System

    International Nuclear Information System (INIS)

    Qin, J; Bauer, M A

    2010-01-01

    The analysis of synchrotron X-ray Diffraction (XRD) data has been used by scientists and engineers to understand and predict properties of materials. However, the large volume of XRD image data and the intensive computations involved in the data analysis makes it hard for researchers to quickly reach any conclusions about the images from an experiment when using conventional XRD data analysis software. Synchrotron time is valuable and delays in XRD data analysis can impact decisions about subsequent experiments or about materials that they are investigating. In order to improve the data analysis performance, ideally to achieve near real time data analysis during an XRD experiment, we designed and implemented software for accelerated XRD data analysis. The software has been developed for a heterogeneous high performance computing (HPC) system, comprised of IBM PowerXCell 8i processors and Intel quad-core Xeon processors. This paper describes the software and reports on the improved performance. The results indicate that it is possible for XRD data to be analyzed at the rate it is being produced.

  10. Petawatt laser system for the fast ignition studies at ILE, Osaka University

    International Nuclear Information System (INIS)

    Izawa, Y.

    2002-01-01

    We have developed a PW Nd:glass laser system, which can deliver 1 PW output with 500 J in 0.5 ps, to study a fast ignitor concept in laser fusion. In the front end of this system, the optical parametric chirped-pulse amplifier (OPCPA) was introduced. The OPCPA solves several problems arising in an existing Ti:sapphire regenerative amplifier, such as low single-pass gain, high prepulse and output fluctuation. A booster amplifier is a Cassegrain-type three pass disk system having a 350 mm clear aperture, which generated 1.1 kJ output energy with the spectral width of 3.7 nm corresponding to 0.5 ps in Fourier transform limited pulse. The spatial phase aberration mainly caused in the booster amplifier is corrected using a deformable mirror. The laser pulse is compressed by a pair of 1-m diffraction gratings and focused by a parabolic mirror. The timing jitter between PW laser and GEKKO XII is less than 10 ps, which was attained by injecting a weak pulse splitted out from the front end into the preamplifier of GEKKO XII. (author)

  11. Design of a laser scanner for a digital mammography system.

    Science.gov (United States)

    Rowlands, J A; Taylor, J E

    1996-05-01

    We have developed a digital readout system for radiographic images using a scanning laser beam. In this system, electrostatic charge images on amorphous selenium (alpha-Se) plates are read out using photo-induced discharge (PID). We discuss the design requirements of a laser scanner for the PID system and describe its construction from commercially available components. The principles demonstrated can be adapted to a variety of digital imaging systems.

  12. High average power solid state laser power conditioning system

    International Nuclear Information System (INIS)

    Steinkraus, R.F.

    1987-01-01

    The power conditioning system for the High Average Power Laser program at Lawrence Livermore National Laboratory (LLNL) is described. The system has been operational for two years. It is high voltage, high power, fault protected, and solid state. The power conditioning system drives flashlamps that pump solid state lasers. Flashlamps are driven by silicon control rectifier (SCR) switched, resonant charged, (LC) discharge pulse forming networks (PFNs). The system uses fiber optics for control and diagnostics. Energy and thermal diagnostics are monitored by computers

  13. Laser metrology in food-related systems

    Science.gov (United States)

    Mendoza-Sanchez, Patricia; Lopez, Daniel; Kongraksawech, Teepakorn; Vazquez, Pedro; Torres, J. Antonio; Ramirez, Jose A.; Huerta-Ruelas, Jorge

    2005-02-01

    An optical system was developed using a low-cost semiconductor laser and commercial optical and electronic components, to monitor food processes by measuring changes in optical rotation (OR) of chiral compounds. The OR signal as a function of processing time and sample temperature were collected and recorded using a computer data acquisition system. System has been tested during two different processes: sugar-protein interaction and, beer fermentation process. To study sugar-protein interaction, the following sugars were used: sorbitol, trehalose and sucrose, and in the place of Protein, Serum Albumin Bovine (BSA, A-7906 Sigma-Aldrich). In some food processes, different sugars are added to protect damage of proteins during their processing, storage and/or distribution. Different sugar/protein solutions were prepared and heated above critical temperature of protein denaturation. OR measurements were performed during heating process and effect of different sugars in protein denaturation was measured. Higher sensitivity of these measurements was found compared with Differential Scanning Calorimetry, which needs higher protein concentration to study these interactions. The brewing fermentation process was monitored in-situ using this OR system and validated by correlation with specific density measurements and gas chromatography. This instrument can be implemented to monitor fermentation on-line, thereby determining end of process and optimizing process conditions in an industrial setting. The high sensitivity of developed OR system has no mobile parts and is more flexible than commercial polarimeters providing the capability of implementation in harsh environments, signifying the potential of this method as an in-line technique for quality control in food processing and for experimentation with optically active solutions.

  14. Diffractive elements performance in chromatic confocal microscopy

    International Nuclear Information System (INIS)

    Garzon, J; Duque, D; Alean, A; Toledo, M; Meneses, J; Gharbi, T

    2011-01-01

    The Confocal Laser Scanning Microscopy (CLSM) has been widely used in the semiconductor industry and biomedicine because of its depth discrimination capability. Subsequent to this technique has been developed in recent years Chromatic Confocal Microscopy. This method retains the same principle of confocal and offers the added advantage of removing the axial movement of the moving system. This advantage is usually accomplished with an optical element that generates a longitudinal chromatic aberration and a coding system that relates the axial position of each point of the sample with the wavelength that is focused on each. The present paper shows the performance of compact chromatic confocal microscope when some different diffractive elements are used for generation of longitudinal chromatic aberration. Diffractive elements, according to the process and manufacturing parameters, may have different diffraction efficiency and focus a specific wavelength in a specific focal position. The performance assessment is carried out with various light sources which exhibit an incoherent behaviour and a broad spectral width.

  15. Laser and plasma diagnostics for the OMEGA Upgrade Laser System (invited) (abstract)

    International Nuclear Information System (INIS)

    Letzring, S.A.

    1995-01-01

    The upgraded OMEGA laser system will be capable of delivering up to 30 kJ of 351-nm laser light with various temporal pulse shapes onto a variety of targets for both ICF and basic plasma physics experiments. ICF experiments will cover a wide parameter space up to near-ignition conditions, and basic interaction and plasma physics experiments will cover previously unattainable parameter spaces. The laser system is the tool with which the experiments are performed; the diagnostics, both of the laser system and the interaction between the laser and the target, form the heart of the experiment. A new suite of diagnostics is now being designed and constructed. Most of these are based on diagnostics previously fielded on the OMEGA laser system very successfully over the last ten years, but there are some new diagnostics, both for the laser and the interaction experiments, which have had to be invented. Laser system diagnostics include high-energy, full-beam calorimetry for all of the 60 beams of the upgrade; a novel, multispectral energy-measuring system for assessing the tuning of the frequency-multiplying crystals; a beam-balance diagnostic that forms the heart of the energy-balance system; and a peak power diagnostic that forms the heart of the power-balance system. Target diagnostics will include the usual time-integrated x-ray imaging systems, both pinhole cameras and x-ray microscopes; x-ray spectrometers, both imaging and spatially integrating; plamsa calorimeters, including x-ray calorimetry; and time-resolved x-ray diagnostics, both nonimaging and imaging in one and two dimensions. Neutron diagnostics will include several measurements of total yield, secondary, and possibly tertiary yield and neutron spectroscopy with several time-of-flight spectrometers. Other measurements will include ''knock-on'' particle measurements and neutron activation of shell materials as a diagnostic of compressed fuel and shell density

  16. Laser cutting of irregular shape object based on stereo vision laser galvanometric scanning system

    Science.gov (United States)

    Qi, Li; Zhang, Yixin; Wang, Shun; Tang, Zhiqiang; Yang, Huan; Zhang, Xuping

    2015-05-01

    Irregular shape objects with different 3-dimensional (3D) appearances are difficult to be shaped into customized uniform pattern by current laser machining approaches. A laser galvanometric scanning system (LGS) could be a potential candidate since it can easily achieve path-adjustable laser shaping. However, without knowing the actual 3D topography of the object, the processing result may still suffer from 3D shape distortion. It is desirable to have a versatile auxiliary tool that is capable of generating 3D-adjusted laser processing path by measuring the 3D geometry of those irregular shape objects. This paper proposed the stereo vision laser galvanometric scanning system (SLGS), which takes the advantages of both the stereo vision solution and conventional LGS system. The 3D geometry of the object obtained by the stereo cameras is used to guide the scanning galvanometers for 3D-shape-adjusted laser processing. In order to achieve precise visual-servoed laser fabrication, these two independent components are integrated through a system calibration method using plastic thin film target. The flexibility of SLGS has been experimentally demonstrated by cutting duck feathers for badminton shuttle manufacture.

  17. Characterization for solidification and phase transformations of pure-titanium steel weld metal with time-resolved X-ray diffraction system

    International Nuclear Information System (INIS)

    Terasaki, Hidenori; Komizo, Yu-ichi; Nishino, Fumihiro; Ikeda, Masahiko

    2007-01-01

    Understanding and controlling solidification and phase transformation process of weld metal is essential for forming the microstructure with superior mechanical property. Recent evolution of analysis technique makes for solidification and phase transformation process to be in-situ analyzed, in direct and reciprocal lattice space. In the present work, unidirectional-solidification and phase transformation in the weld metal of commercial pure-titanium in Gas Tungsten Arc welding was in-situ observed by using Time-Resolved X-Ray Diffraction system with two-dimensional pixel detector. An undulator beam was used as a probe. Larger diffraction area could be detected in the time-resolution of 0.05 seconds, in unidirectional solidification and subsequent phase transformation process of pure-titanium weld metal. Furthermore, the microstructure formation during β-α phase transformation was in situ observed with High temperature Laser Scanning Confocal Microscopy. The crystal configurations in unidirectional solidification of weld metal and rapid change of phase ratio in reconstructive phase transformation were clearly analyzed. (author)

  18. Bragg diffraction of fermions at optical potentials

    International Nuclear Information System (INIS)

    Deh, Benjamin

    2008-01-01

    This thesis describes the Bragg diffraction of ultracold fermions at an optical potential. A moving optical lattice was created, by overlaying two slightly detuned lasers. Atoms can be diffracted at this lattice if the detuning fulfills the Bragg condition for resting atoms. This Bragg diffraction is analyzed systematically in this thesis. To this end Rabi oscillations between the diffraction states were driven, as well in the weakly interacting Bragg regime, as in the strongly interacting Kapitza-Dirac regime. Simulations, based on a driven two-, respectively multilevel-system describe the observed effects rather well. Furthermore, the temporal evolution of the diffracted states in the magnetic trapping potential was studied. The anharmonicity of the trap in use and the scattering cross section for p-wave collisions in a 6 Li system was determined from the movement of these states. Moreover the momentum distribution of the fermions was measured with Bragg spectroscopy and first signs of Fermi degeneracy were found. Finally an interferometer with fermions was build, exhibiting a coherence time of more than 100 μs. With this, the possibility for measurement and manipulation of ultracold fermions with Bragg diffraction could bee shown. (orig.)

  19. Time-resolved X-ray diffraction with accelerator- and laser-plasma-based X-ray sources

    International Nuclear Information System (INIS)

    Nicoul, Matthieu

    2010-01-01

    Femtosecond X-ray pulses are a powerful tool to investigate atomic motions triggered by femtosecond pump pulses. This thesis is dedicated to the production of such pulses and their use in optical pump - X-ray probe measurement. This thesis describes the laser-plasma-based sources available at the University of Duisburg-Essen. Part of it consists of the description of the design, built-up and characterization of a new ''modular'' X-ray source dedicated to optimize the X-ray flux onto the sample under investigation. The acoustic wave generation in femtosecond optically excited semiconductor (gallium arsenide) and metal (gold) was performed using the sources of the University of Duisburg-Essen. The physical answer of the material was modeled by a simple strain model for the semiconductor, pressure model for the metal, in order to gain information on the interplay of the electronic and thermal pressures rising after excitation. Whereas no reliable information could be obtain in gallium arsenide (principally due to the use of a bulk), the model for gold achieved very good agreement, providing useful information. The relaxation time of the electron to lattice energy was found to be (5.0±0.3) ps, and the ratio of the Grueneisen parameters was found to be γ e / γ i = (0.5±0.1). This thesis also describes the Sub-Picosecond Pulse Source (SPPS) which existed at the (formally) Stanford Linear Accelerator Center, an accelerator-based X-ray source, and two measurements performed with it. The first one is the detailed investigation of the phonon softening of the A 1g mode launch in bismuth upon fluence excitation. Detailed information concerning the new equilibrium position and phonon frequency were obtained over extended laser pump fluences. The second measurement concerned the study of the liquid phase dynamics in a newly formed liquid phase following ultrafast melting in indium antimonide. The formation of the liquid phase and its development for excitations close to the

  20. Time-resolved X-ray diffraction with accelerator- and laser-plasma-based X-ray sources

    Energy Technology Data Exchange (ETDEWEB)

    Nicoul, Matthieu

    2010-09-01

    Femtosecond X-ray pulses are a powerful tool to investigate atomic motions triggered by femtosecond pump pulses. This thesis is dedicated to the production of such pulses and their use in optical pump - X-ray probe measurement. This thesis describes the laser-plasma-based sources available at the University of Duisburg-Essen. Part of it consists of the description of the design, built-up and characterization of a new ''modular'' X-ray source dedicated to optimize the X-ray flux onto the sample under investigation. The acoustic wave generation in femtosecond optically excited semiconductor (gallium arsenide) and metal (gold) was performed using the sources of the University of Duisburg-Essen. The physical answer of the material was modeled by a simple strain model for the semiconductor, pressure model for the metal, in order to gain information on the interplay of the electronic and thermal pressures rising after excitation. Whereas no reliable information could be obtain in gallium arsenide (principally due to the use of a bulk), the model for gold achieved very good agreement, providing useful information. The relaxation time of the electron to lattice energy was found to be (5.0{+-}0.3) ps, and the ratio of the Grueneisen parameters was found to be {gamma}{sub e} / {gamma}{sub i} = (0.5{+-}0.1). This thesis also describes the Sub-Picosecond Pulse Source (SPPS) which existed at the (formally) Stanford Linear Accelerator Center, an accelerator-based X-ray source, and two measurements performed with it. The first one is the detailed investigation of the phonon softening of the A{sub 1g} mode launch in bismuth upon fluence excitation. Detailed information concerning the new equilibrium position and phonon frequency were obtained over extended laser pump fluences. The second measurement concerned the study of the liquid phase dynamics in a newly formed liquid phase following ultrafast melting in indium antimonide. The formation of the liquid phase

  1. Construction of a femtosecond laser microsurgery system.

    Science.gov (United States)

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

    2010-03-01

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

  2. Application of in situ x-ray diffraction techniques in heterogenous catalytic systems

    International Nuclear Information System (INIS)

    Sharifah Bee Abd Hamid

    2002-01-01

    A broad range of techniques is available today for the characterisation of catalysts and the investigation of catalyst reaction mechanisms. However, only a limited number of those are suitable for in situ studies, i.e experiments performed in conditions mimicking or close as possible to real operating conditions. Various commercially and in-house developed in situ X-Ray diffraction (XRD) cells have been used to obtain information on the phase and structure of materials at the initial formation stage, activation methodology, calcination, reduction and carburization. A major advantage of the in situ X-ray cells is that it allows direct observations on the decomposition of precursors leading to various phases in a controlled environment, i.e. controlled temperature and pressure under specified gases. The cells can be operated both at high temperatures and high pressures, equipped with Position Sensitive Detector (PSD), feature which was used to study phase transformation occurring during the activation of various solids. In MoO 3 , XRD results provide detailed information on the hydrogen insertion into its lattice, followed by carburization providing good understanding on the mechanism in the solid transformation leading to the metastable MoC 1 -x phase. For the Bi-SnO x systems, the environmental cell coupled with XRD and PSD allow the design of activation procedure to obtain the active Bi 2 Sn 2 O 7 . The in situ XRD technique reveals crucial information on the initial stage of oxides formations prior to condensation reaction shown in MCM-41 and titania systems. In this presentation, discussions on general achievements and problems relating to the use of in situ XRD techniques as well as of specific examples selected to illustrate the use and potential of in situ XRD are made. It is not intended to be a review of the art but a highlight of the challenges which the catalytic and material scientists face when entering the avenue. (Author)

  3. A digital intensity stabilization system for HeNe laser

    Science.gov (United States)

    Wei, Zhimeng; Lu, Guangfeng; Yang, Kaiyong; Long, Xingwu; Huang, Yun

    2012-02-01

    A digital intensity stabilization system for HeNe laser is developed. Based on a switching power IC to design laser power supply and a general purpose microcontroller to realize digital PID control, the system constructs a closed loop to stabilize the laser intensity by regulating its discharge current. The laser tube is made of glass ceramics and its integrated structure is steady enough to eliminate intensity fluctuations at high frequency and attenuates all intensity fluctuations, and this makes it easy to tune the control loop. The control loop between discharge current and photodiode voltage eliminates the long-term drifts. The intensity stability of the HeNe laser with this system is 0.014% over 12 h.

  4. Investigation of dye laser excitation of atomic systems

    International Nuclear Information System (INIS)

    Abate, J.A.

    1977-01-01

    A stabilized cw dye laser system and an optical pumping scheme for a sodium atomic beam were developed, and the improvements over previously existing systems are discussed. A method to stabilize both the output intensity and the frequency of the cw dye laser for periods of several hours is described. The fluctuation properties of this laser are investigated by photon counting and two-time correlation measurements. The results show significant departures from the usual single-mode laser theory in the region of threshold and below. The implications of the deviation from accepted theory are discussed. The atomic beam system that was constructed and tested is described. A method of preparing atomic sodium so that it behaves as a simple two-level atom is outlined, and the results of some experiments to study the resonant interaction between the atoms and the dye laser beam are presented

  5. Blue laser diode (450 nm) systems for welding copper

    Science.gov (United States)

    Silva Sa, M.; Finuf, M.; Fritz, R.; Tucker, J.; Pelaprat, J.-M.; Zediker, M. S.

    2018-02-01

    This paper will discuss the development of high power blue laser systems for industrial applications. The key development enabling high power blue laser systems is the emergence of high power, high brightness laser diodes at 450 nm. These devices have a high individual brightness rivaling their IR counterparts and they have the potential to exceed their performance and price barriers. They also have a very high To resulting in a 0.04 nm/°C wavelength shift. They have a very stable lateral far-field profile which can be combined with other diodes to achieve a superior brightness. This paper will report on the characteristics of the blue laser diodes, their integration into a modular laser system suitable for scaling the output power to the 1 kW level and beyond. Test results will be presented for welding of copper with power levels ranging from 150 Watts to 600 Watts

  6. Neutron diffraction study of phase relationship of Ti-C-H system

    International Nuclear Information System (INIS)

    Khidirov, I.; Mukhtarova, N.N.; Mirzaev, B.B.; Serikbaev, B.T.; Zaginaichenko, S.Yu.; Schur, D.V.; Pishuk, V.K.; Kuzmenko, L.V.; Garbuz, V.V.; Nuzhda, S.V.; Pishuk, O.V.

    2006-01-01

    Full text: Due to such properties as high temperature of melting, solidity, stability in aggressive environments, etc., titanium carbide is widely used in modern techniques. It is necessary to know the phase relationships in Ti-C system for scientifically proved using. According to the phase diagram of Ti-C system, there are three phases in it: the solid solutions of carbon in the hexagonal lattice of α-Ti and in the body-centered cubic (BCC) lattice of β-Ti with rather limited solubility and also the face-centered cubic (FCC) titanium carbide TiC x with wide homogeneity range (TiC 0,32 / TiC 1,00 ). A number of the ordered phases was observed on the basis of FCC-phase. It is known, that even insignificant hydrogen impurity strongly influences at the phase relations in Ti-C system. At the same time because of specificity of some technologies of titanium carbide reception, it contains an impurity of hydrogen in its composition. However influence of hydrogen on phase relations of Ti-C system is not investigated enough. The aim of the work is to study hydrogen influence on the phase relations in Ti-C system by neutron (λ =1.085 A) and X-ray ( λ =1.5418 A) diffraction methods. Samples of TiC x H y (x = C/Ti, y H/Ti) were synthesized in the wide interval of carbon and hydrogen concentrations by sintering method from the powder of titanium of PTS trade-mark containing 0,35 mass % of hydrogen, by addition both of given quantity of TiH 2 and of soot of the trade-mark 'very pure'; the samples were studied by neutron and X-ray diffraction methods. Quartz ampoules with briquettes of the samples were pumped out up to vacuum of 1.33 10'-'4 Pa at the room temperature and were sintered in the furnace using the special regime selected by us. The briquettes were annealed from the temperature of 600 deg. C. As our experiments show, at this temperature the formation of Ti 2 C 1-x H 2-x solid solution and rapid absorption of hydrogen by this solution were observed. Also at this

  7. lambda-3, Sandia's 100-J HF laser system

    International Nuclear Information System (INIS)

    Klein, R.A.

    1979-09-01

    Sandia's lambda-geometry intermediate electron-beam-initiated HF amplifier is described in sufficient detail such that a similar system could be designed, constructed and characterized. Items included are the design of the laser cell, magnetic field design and measurements, electron-beam calorimetry, and typical laser results

  8. DFB fiber laser as source for optical communication systems

    DEFF Research Database (Denmark)

    Varming, Poul; Hübner, Jörg; Kristensen, Martin

    1997-01-01

    The results demonstrate that DFB fiber lasers are an attractive alternative as sources in telecommunication systems. The lasers show excellent long-term stability with very high signal to noise ratio and a reasonable output power, combined with exceptional temperature stability and inherent fiber...

  9. Mechanical technology unique to laser fusion experimental systems

    International Nuclear Information System (INIS)

    Hurley, C.A.

    1980-01-01

    Hardware design for laser fusion experimental machines has led to a combination of engineering technologies that are critical to the successful operation of these machines. These large opto-mechanical systems are dependent on extreme cleanliness, accommodation to efficient maintenance, and high stability. These three technologies are the primary mechanical engineering criteria for laser fusion devices

  10. Optical System Design and Integration of the Mercury Laser Altimeter

    Science.gov (United States)

    Ramos-Izquierdo, Luis; Scott, V. Stanley, III; Schmidt, Stephen; Britt, Jamie; Mamakos, William; Trunzo, Raymond; Cavanaugh, John; Miller, Roger

    2005-01-01

    The Mercury Laser Altimeter (MLA). developed for the 2004 MESSENGER mission to Mercury, is designed to measure the planet's topography via laser ranging. A description of the MLA optical system and its measured optical performance during instrument-level and spacecraft-level integration and testing are presented.

  11. Development of LD pumped 10 J x 10 Hz Nd: Glass slab laser system

    International Nuclear Information System (INIS)

    Yamanaka, Masanobu; Kanabe, Tadashi; Matsui, Hideki

    2000-01-01

    As a first step of a driver development for the inertial fusion energy, we are developing a diode-pumped zig-zag Nd: glass slab laser amplifier system which can generate an output of 10 J per pulse at 1053 nm in 10 Hz operation. The water-cooled zig-zag Nd: glass slab is pumped from both sides by 803-nm AlGaAs laser-diode (LD) module; each LD module has an emitting area of 420 mm x 10 mm and two LD modules generated in total 200 kW peak power with 2.5 kW/cm 2 peak intensity at 10 Hz repetition rate. We have obtained in a preliminary experiment a 8.5 J output energy at 0.5 Hz with beam quality of 2 times diffraction limited far-field pattern. (author)

  12. The Gaussian beam mode analysis of classical phase aberrations in diffraction-limited optical systems

    Science.gov (United States)

    Trappe, Neil; Murphy, J. Anthony; Withington, Stafford

    2003-07-01

    Gaussian beam mode analysis (GBMA) offers a more intuitive physical insight into how light beams evolve as they propagate than the conventional Fresnel diffraction integral approach. In this paper we illustrate that GBMA is a computationally efficient, alternative technique for tracing the evolution of a diffracting coherent beam. In previous papers we demonstrated the straightforward application of GBMA to the computation of the classical diffraction patterns associated with a range of standard apertures. In this paper we show how the GBMA technique can be expanded to investigate the effects of aberrations in the presence of diffraction by introducing the appropriate phase error term into the propagating quasi-optical beam. We compare our technique to the standard diffraction integral calculation for coma, astigmatism and spherical aberration, taking—for comparison—examples from the classic text 'Principles of Optics' by Born and Wolf. We show the advantages of GBMA for allowing the defocusing of an aberrated image to be evaluated quickly, which is particularly important and useful for probing the consequences of astigmatism and spherical aberration.

  13. The Gaussian beam mode analysis of classical phase aberrations in diffraction-limited optical systems

    International Nuclear Information System (INIS)

    Trappe, Neil; Murphy, J Anthony; Withington, Stafford

    2003-01-01

    Gaussian beam mode analysis (GBMA) offers a more intuitive physical insight into how light beams evolve as they propagate than the conventional Fresnel diffraction integral approach. In this paper we illustrate that GBMA is a computationally efficient, alternative technique for tracing the evolution of a diffracting coherent beam. In previous papers we demonstrated the straightforward application of GBMA to the computation of the classical diffraction patterns associated with a range of standard apertures. In this paper we show how the GBMA technique can be expanded to investigate the effects of aberrations in the presence of diffraction by introducing the appropriate phase error term into the propagating quasi-optical beam. We compare our technique to the standard diffraction integral calculation for coma, astigmatism and spherical aberration, taking - for comparison - examples from the classic text 'Principles of Optics' by Born and Wolf. We show the advantages of GBMA for allowing the defocusing of an aberrated image to be evaluated quickly, which is particularly important and useful for probing the consequences of astigmatism and spherical aberration

  14. Non-contact finger vein acquisition system using NIR laser

    Science.gov (United States)

    Kim, Jiman; Kong, Hyoun-Joong; Park, Sangyun; Noh, SeungWoo; Lee, Seung-Rae; Kim, Taejeong; Kim, Hee Chan

    2009-02-01

    Authentication using finger vein pattern has substantial advantage than other biometrics. Because human vein patterns are hidden inside the skin and tissue, it is hard to forge vein structure. But conventional system using NIR LED array has two drawbacks. First, direct contact with LED array raise sanitary problem. Second, because of discreteness of LEDs, non-uniform illumination exists. We propose non-contact finger vein acquisition system using NIR laser and Laser line generator lens. Laser line generator lens makes evenly distributed line laser from focused laser light. Line laser is aimed on the finger longitudinally. NIR camera was used for image acquisition. 200 index finger vein images from 20 candidates are collected. Same finger vein pattern extraction algorithm was used to evaluate two sets of images. Acquired images from proposed non-contact system do not show any non-uniform illumination in contrary with conventional system. Also results of matching are comparable to conventional system. We developed Non-contact finger vein acquisition system. It can prevent potential cross contamination of skin diseases. Also the system can produce uniformly illuminated images unlike conventional system. With the benefit of non-contact, proposed system shows almost equivalent performance compared with conventional system.

  15. Railgun system using a laser-induced plasma armature

    International Nuclear Information System (INIS)

    Onozuka, M.; Oda, Y.; Azuma, K.

    1996-01-01

    Development of an electromagnetic railgun system that utilizes a laser-induced plasma armature formation has been conducted to investigate the application of the railgun system for high-speed pellet injection into fusion plasmas. Using the laser-induced plasma formation technique, the required breakdown voltage was reduced by one-tenth compared with that for the spark-discharged plasma. The railgun system successfully accelerated the laser-induced plasma armature by an electromagnetic force that accelerated the pellet. The highest velocity of the solid hydrogen pellets, obtained so far, was 2.6 km/sec using a 2m-long railgun. copyright 1996 American Institute of Physics

  16. Railgun system using a laser-induced plasma armature

    Science.gov (United States)

    Onozuka, Masanori; Oda, Yasushi; Azuma, Kingo

    1996-05-01

    Development of an electromagnetic railgun system that utilizes a laser-induced plasma armature formation has been conducted to investigate the application of the railgun system for high-speed pellet injection into fusion plasmas. Using the laser-induced plasma formation technique, the required breakdown voltage was reduced by one-tenth compared with that for the spark-discharged plasma. The railgun system successfully accelerated the laser-induced plasma armature by an electromagnetic force that accelerated the pellet. The highest velocity of the solid hydrogen pellets, obtained so far, was 2.6 km/sec using a 2m-long railgun.

  17. Railgun system using a laser-induced plasma armature

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, M.; Oda, Y.; Azuma, K. [Mitsubishi Heavy Industries, Ltd., 3-3-1, Minatomirai, Nishi-ku, Yokohama 220-84 (Japan)

    1996-05-01

    Development of an electromagnetic railgun system that utilizes a laser-induced plasma armature formation has been conducted to investigate the application of the railgun system for high-speed pellet injection into fusion plasmas. Using the laser-induced plasma formation technique, the required breakdown voltage was reduced by one-tenth compared with that for the spark-discharged plasma. The railgun system successfully accelerated the laser-induced plasma armature by an electromagnetic force that accelerated the pellet. The highest velocity of the solid hydrogen pellets, obtained so far, was 2.6 km/sec using a 2m-long railgun. {copyright} {ital 1996 American Institute of Physics.}

  18. A laser calibration system for the STAR TPC

    CERN Document Server

    Lebedev, A

    2002-01-01

    A Time Projection Chamber (TPC) is the primary tracking detector for the STAR experiment at RHIC. A laser calibration system was built to calibrate and monitor the TPC tracking performance. The laser system uses a novel design which produces approx 500 thin, ionizing beams distributed throughout the tracking volume. This new approach is significantly simpler than the traditional ones, and provides complete TPC coverage at a reduced cost. The laser system was used during the RHIC 2000 summer run to measure drift velocities with about 0.02% accuracy and to monitor the TPC performance. Calibration runs were made with and without a magnetic field to check B field map corrections.

  19. Thin-Film Polarizers for the OMEGA EP Laser System

    International Nuclear Information System (INIS)

    Oliver, J.B.; Rigatti, A.L.; Howe, J.D.; Keck, J.; Szczepanski, J.; Schmid, A.W.; Papernov, S.; Kozlov, A.; Kosc, T.Z.

    2006-01-01

    Thin-film polarizers are essential components of large laser systems such as OMEGA EP and the NIF because of the need to switch the beam out of the primary laser cavity (in conjunction with a plasma-electrode Pockels cell) as well as providing a well-defined linear polarization for frequency conversion and protecting the system from back-reflected light. The design and fabrication of polarizers for pulse-compressed laser systems is especially challenging because of the spectral bandwidth necessary for chirped-pulse amplification

  20. Coherent Laser Radar Metrology System for Large Scale Optical Systems, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A new type of laser radar metrology inspection system is proposed that incorporates a novel, dual laser coherent detection scheme capable of eliminating both...

  1. Comparison of fluvial suspended-sediment concentrations and particle-size distributions measured with in-stream laser diffraction and in physical samples

    Science.gov (United States)

    Czuba, Jonathan A.; Straub, Timothy D.; Curran, Christopher A.; Landers, Mark N.; Domanski, Marian M.

    2015-01-01

    Laser-diffraction technology, recently adapted for in-stream measurement of fluvial suspended-sediment concentrations (SSCs) and particle-size distributions (PSDs), was tested with a streamlined (SL), isokinetic version of the Laser In-Situ Scattering and Transmissometry (LISST) for measuring volumetric SSCs and PSDs ranging from 1.8-415 µm in 32 log-spaced size classes. Measured SSCs and PSDs from the LISST-SL were compared to a suite of 22 datasets (262 samples in all) of concurrent suspended-sediment and streamflow measurements using a physical sampler and acoustic Doppler current profiler collected during 2010-12 at 16 U.S. Geological Survey streamflow-gaging stations in Illinois and Washington (basin areas: 38 – 69,264 km2). An unrealistically low computed effective density (mass SSC / volumetric SSC) of 1.24 g/ml (95% confidence interval: 1.05-1.45 g/ml) provided the best-fit value (R2 = 0.95; RMSE = 143 mg/L) for converting volumetric SSC to mass SSC for over 2 orders of magnitude of SSC (12-2,170 mg/L; covering a substantial range of SSC that can be measured by the LISST-SL) despite being substantially lower than the sediment particle density of 2.67 g/ml (range: 2.56-2.87 g/ml, 23 samples). The PSDs measured by the LISST-SL were in good agreement with those derived from physical samples over the LISST-SL's measureable size range. Technical and operational limitations of the LISST-SL are provided to facilitate the collection of more accurate data in the future. Additionally, the spatial and temporal variability of SSC and PSD measured by the LISST-SL is briefly described to motivate its potential for advancing our understanding of suspended-sediment transport by rivers.

  2. Optical system for laser triggering of PBFA II

    International Nuclear Information System (INIS)

    Hamil, R.A.; Seamons, L.O.; Schanwald, L.P.; Gerber, R.A.

    1985-01-01

    The PBFA II laser triggering optical system consists of nearly 300 optical components. These optics must be sufficiently precise to preserve the laser beam quality, as well as to equally distribute the energy of the UV laser beam to the 36, 5.5 MV gas-filled switches at precisely the same instant. Both index variation and cleanliness of the air long the laser path must be controlled. The manual alignment system is capable of alignment to better than the acceptable error of 200 microradians (laser to switches). A technique has been devised to ease the alignment procedure by using a special high gain video camera and a tool alignment telescope to view retroreflective tape targets having optical brightness gains over white surfaces of 10/sup 3/. The camera is a charge-coupled detector intensified by a double microchannel plate having an optical gain of between 10/sup 4/ and 10/sup 5/

  3. Introducing the ARL X'Tra x-ray diffraction system

    International Nuclear Information System (INIS)

    Harris, L.

    2002-01-01

    Full text: The ARL X'Tra is a state-of-the-art solution for powder X-ray diffraction in a large range of applications such as pharmaceuticals and biosciences, chemicals, earth sciences, semi-conductors, metallurgy and ceramics. The X'Tra offers the latest technology in key diffraction components to produce a high performance instrument at an affordable price. This presentation examines some of the hardware and performance features of this instrument. Copyright (2002) Australian X-ray Analytical Association Inc

  4. Performance of the Aurora KrF ICF laser system

    International Nuclear Information System (INIS)

    Jones, J.E.; Czuchlewski, S.J.; Turner, T.P.; Watt, R.G.; Thomas, S.J.; Netz, D.A.; Tallman, C.R.; Mack, J.M.; Figueira, J.F.

    1990-01-01

    Because short wavelength lasers are attractive for inertial confinement fusion (ICF), the Department of Energy is sponsoring work at Los Alamos National Laboratory in krypton-fluoride (KrF) laser technology. Aurora is a short-pulse, high-power, KrF laser system. It serves as an end-to-end technology demonstration prototype for large-scale ultraviolet laser systems for short wavelength ICF research. The system employs optical angular multiplexing and serial amplification by electron-beam-driven KrF laser amplifiers. The 1 to 5 ns pulse of the Aurora front end is split into 96 beams which are angularly and temporally multiplexed to produce a 480 ns pulse train for amplification by four KrF laser amplifiers. In the present system configuration half (48) of the amplified pulses are demultiplexed using different optical path lengths and delivered simultaneously to target. This paper discusses how the Aurora laser system has entered the initial operational phase by delivering pulse energies of greater than one kilojoule to target

  5. Automated Laser Seeker Performance Evaluation System (ALSPES)

    Data.gov (United States)

    Federal Laboratory Consortium — This facility provides complete open-loop test capability for semi-active laser (SAL) seekers/sensors operating at 1.064 microns. ALSPES provides characterizations...

  6. Laser-GMA Hybrid Pipe Welding System

    National Research Council Canada - National Science Library

    Reutzel, Edward W; Kern, Ludwig; Sullivan, Michael J; Tressler, Jay F; Avalos, Juan

    2007-01-01

    The combination of laser welding with conventional gas metal arc welding technology offers substantial increases in production rate of joining pipe through single-pass joining compared to multi-pass...

  7. A CMOS active pixel sensor system for laboratory- based x-ray diffraction studies of biological tissue

    International Nuclear Information System (INIS)

    Bohndiek, Sarah E; Cook, Emily J; Arvanitis, Costas D; Olivo, Alessandro; Royle, Gary J; Clark, Andy T; Prydderch, Mark L; Turchetta, Renato; Speller, Robert D

    2008-01-01

    X-ray diffraction studies give material-specific information about biological tissue. Ideally, a large area, low noise, wide dynamic range digital x-ray detector is required for laboratory-based x-ray diffraction studies. The goal of this work is to introduce a novel imaging technology, the CMOS active pixel sensor (APS) that has the potential to fulfil all these requirements, and demonstrate its feasibility for coherent scatter imaging. A prototype CMOS APS has been included in an x-ray diffraction demonstration system. An industrial x-ray source with appropriate beam filtration is used to perform angle dispersive x-ray diffraction (ADXRD). Optimization of the experimental set-up is detailed including collimator options and detector operating parameters. Scatter signatures are measured for 11 different materials, covering three medical applications: breast cancer diagnosis, kidney stone identification and bone mineral density calculations. Scatter signatures are also recorded for three mixed samples of known composition. Results are verified using two independent models for predicting the APS scatter signature: (1) a linear systems model of the APS and (2) a linear superposition integral combining known monochromatic scatter signatures with the input polychromatic spectrum used in this case. Cross validation of experimental, modelled and literature results proves that APS are able to record biologically relevant scatter signatures. Coherent scatter signatures are sensitive to multiple materials present in a sample and provide a means to quantify composition. In the future, production of a bespoke APS imager for x-ray diffraction studies could enable simultaneous collection of the transmitted beam and scattered radiation in a laboratory-based coherent scatter system, making clinical transfer of the technique attainable

  8. Combined laser ultrasonics, laser heating, and Raman scattering in diamond anvil cell system

    Science.gov (United States)

    Zinin, Pavel V.; Prakapenka, Vitali B.; Burgess, Katherine; Odake, Shoko; Chigarev, Nikolay; Sharma, Shiv K.

    2016-12-01

    We developed a multi-functional in situ measurement system under high pressure equipped with a laser ultrasonics (LU) system, Raman device, and laser heating system (LU-LH) in a diamond anvil cell (DAC). The system consists of four components: (1) a LU-DAC system (probe and pump lasers, photodetector, and oscilloscope) and DAC; (2) a fiber laser, which is designed to allow precise control of the total power in the range from 2 to 100 W by changing the diode current, for heating samples; (3) a spectrometer for measuring the temperature of the sample (using black body radiation), fluorescence spectrum (spectrum of the ruby for pressure measurement), and Raman scattering measurements inside a DAC under high pressure and high temperature (HPHT) conditions; and (4) an optical system to focus laser beams on the sample and image it in the DAC. The system is unique and allows us to do the following: (a) measure the shear and longitudinal velocities of non-transparent materials under HPHT; (b) measure temperature in a DAC under HPHT conditions using Planck's law; (c) measure pressure in a DAC using a Raman signal; and (d) measure acoustical properties of small flat specimens removed from the DAC after HPHT treatment. In this report, we demonstrate that the LU-LH-DAC system allows measurements of velocities of the skimming waves in iron at 2580 K and 22 GPa.

  9. On-Chip Laser-Power Delivery System for Dielectric Laser Accelerators

    Science.gov (United States)

    Hughes, Tyler W.; Tan, Si; Zhao, Zhexin; Sapra, Neil V.; Leedle, Kenneth J.; Deng, Huiyang; Miao, Yu; Black, Dylan S.; Solgaard, Olav; Harris, James S.; Vuckovic, Jelena; Byer, Robert L.; Fan, Shanhui; England, R. Joel; Lee, Yun Jo; Qi, Minghao

    2018-05-01

    We propose an on-chip optical-power delivery system for dielectric laser accelerators based on a fractal "tree-network" dielectric waveguide geometry. This system replaces experimentally demanding free-space manipulations of the driving laser beam with chip-integrated techniques based on precise nanofabrication, enabling access to orders-of-magnitude increases in the interaction length and total energy gain for these miniature accelerators. Based on computational modeling, in the relativistic regime, our laser delivery system is estimated to provide 21 keV of energy gain over an acceleration length of 192 μ m with a single laser input, corresponding to a 108-MV/m acceleration gradient. The system may achieve 1 MeV of energy gain over a distance of less than 1 cm by sequentially illuminating 49 identical structures. These findings are verified by detailed numerical simulation and modeling of the subcomponents, and we provide a discussion of the main constraints, challenges, and relevant parameters with regard to on-chip laser coupling for dielectric laser accelerators.

  10. Excimer laser beam delivery systems for medical applications

    Science.gov (United States)

    Kubo, Uichi; Hashishin, Yuichi; Okada, Kazuyuki; Tanaka, Hiroyuki

    1993-05-01

    We have been doing the basic experiments of UV laser beams and biotissue interaction with both KrF and XeCl lasers. However, the conventional optical fiber can not be available for power UV beams. So we have been investigating about UV power beam delivery systems. These experiments carry on with the same elements doped quartz fibers and the hollow tube. The doped elements are OH ion, chlorine and fluorine. In our latest work, we have tried ArF excimer laser and biotissue interactions, and the beam delivery experiments. From our experimental results, we found that the ArF laser beam has high incision ability for hard biotissue. For example, in the case of the cow's bone incision, the incision depth by ArF laser was ca.15 times of KrF laser. Therefore, ArF laser would be expected to harden biotissue therapy as non-thermal method. However, its beam delivery is difficult to work in this time. We will develop ArF laser beam delivery systems.

  11. Investigation by laser induced breakdown spectroscopy, X-ray fluorescence and X-ray powder diffraction of the chemical composition of white clay ceramic tiles from Veliki Preslav

    International Nuclear Information System (INIS)

    Blagoev, K.; Grozeva, M.; Malcheva, G.; Neykova, S.

    2013-01-01

    The paper presents the results of the application of laser induced breakdown spectroscopy, X-ray fluorescence spectrometry, and X-ray powder diffraction in assessing the chemical and phase composition of white clay decorative ceramic tiles from the medieval archaeological site of Veliki Preslav, a Bulgarian capital in the period 893–972 AC, well-known for its original ceramic production. Numerous white clay ceramic tiles with highly varied decoration, produced for wall decoration of city's churches and palaces, were found during the archaeological excavations in the old capital. The examination of fourteen ceramic tiles discovered in one of the city's monasteries is aimed at characterization of the chemical profile of the white-clay decorative ceramics produced in Veliki Preslav. Combining different methods and comparing the obtained results provides complementary information regarding the white-clay ceramic production in Veliki Preslav and complete chemical characterization of the examined artefacts. - Highlights: ► LIBS, XRF and XRD analyses of medieval white-clay ceramic tiles fragments are done. ► Different elements and phases, presented in the ceramics fragments were determined. ► Differences in the tiles' raw material mineral composition are found. ► Information of the tiles' production process and the raw clay deposits is obtained

  12. Investigation by laser induced breakdown spectroscopy, X-ray fluorescence and X-ray powder diffraction of the chemical composition of white clay ceramic tiles from Veliki Preslav

    Energy Technology Data Exchange (ETDEWEB)

    Blagoev, K., E-mail: kblagoev@issp.bas.bg [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); Grozeva, M., E-mail: margo@issp.bas.bg [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); Malcheva, G., E-mail: bobcheva@issp.bas.bg [Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 Tzarigradsko Chaussee, 1784 Sofia (Bulgaria); Neykova, S., E-mail: sevdalinaneikova@abv.bg [National Institute of Archaeology with Museum, Bulgarian Academy of Sciences, 2 Saborna, 1000 Sofia (Bulgaria)

    2013-01-01

    The paper presents the results of the application of laser induced breakdown spectroscopy, X-ray fluorescence spectrometry, and X-ray powder diffraction in assessing the chemical and phase composition of white clay decorative ceramic tiles from the medieval archaeological site of Veliki Preslav, a Bulgarian capital in the period 893–972 AC, well-known for its original ceramic production. Numerous white clay ceramic tiles with highly varied decoration, produced for wall decoration of city's churches and palaces, were found during the archaeological excavations in the old capital. The examination of fourteen ceramic tiles discovered in one of the city's monasteries is aimed at characterization of the chemical profile of the white-clay decorative ceramics produced in Veliki Preslav. Combining different methods and comparing the obtained results provides complementary information regarding the white-clay ceramic production in Veliki Preslav and complete chemical characterization of the examined artefacts. - Highlights: ► LIBS, XRF and XRD analyses of medieval white-clay ceramic tiles fragments are done. ► Different elements and phases, presented in the ceramics fragments were determined. ► Differences in the tiles' raw material mineral composition are found. ► Information of the tiles' production process and the raw clay deposits is obtained.

  13. Indoor optical wireless communication system using beam-steering by cascaded diffractive optical elements

    NARCIS (Netherlands)

    Oh, C.W.; Tangdiongga, E.; Koonen, A.M.J.; García-Blanco, S.M.; Boller, Kl.J.; Sefunc, M.A.; Geuzebroek, D.

    2014-01-01

    While the radio spectrum continues to struggle with a soaring bandwidth demand, the optical spectrum promises virtually unlimited license-free bandwidth. We report the feasibility of high-capacity point-to-point links for indoor optical wireless communication with cascaded diffractive optical

  14. Laser display system for multi-depth screen projection scenarios.

    Science.gov (United States)

    La Torre, J Pablo; Mayes, Nathan; Riza, Nabeel A

    2017-11-10

    Proposed is a laser projection display system that uses an electronically controlled variable focus lens (ECVFL) to achieve sharp and in-focus image projection over multi-distance three-dimensional (3D) conformal screens. The system also functions as an embedded distance sensor that enables 3D mapping of the multi-level screen platform before the desired laser scanned beam focused/defocused projected spot sizes are matched to the different localized screen distances on the 3D screen. Compared to conventional laser scanning and spatial light modulator (SLM) based projection systems, the proposed design offers in-focus non-distorted projection over a multi-distance screen zone with varying depths. An experimental projection system for a screen depth variation of 65 cm is demonstrated using a 633 nm laser beam, 3 KHz scan speed galvo-scanning mirrors, and a liquid-based ECVFL. As a basic demonstration, an in-house developed MATLAB based graphic user interface is deployed to work along with the laser projection display, enabling user inputs like text strings or predefined image projection. The user can specify projection screen distance, scanned laser linewidth, projected text font size, projected image dimensions, and laser scanning rate. Projected images are shown highlighting the 3D control capabilities of the display, including the production of a non-distorted image onto two-depths versus a distorted image via dominant prior-art projection methods.

  15. Study of optical Laue diffraction

    International Nuclear Information System (INIS)

    Chakravarthy, Giridhar; Allam, Srinivasa Rao; Satyanarayana, S. V. M.; Sharan, Alok

    2014-01-01

    We present the study of the optical diffraction pattern of one and two-dimensional gratings with defects, designed using desktop pc and printed on OHP sheet using laser printer. Gratings so prepared, using novel low cost technique provides good visual aid in teaching. Diffraction pattern of the monochromatic light (632.8nm) from the grating so designed is similar to that of x-ray diffraction pattern of crystal lattice with point defects in one and two-dimensions. Here both optical and x-ray diffractions are Fraunhofer. The information about the crystalline lattice structure and the defect size can be known

  16. Study of optical Laue diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Chakravarthy, Giridhar, E-mail: cgiridhar84@gmail.com, E-mail: aloksharan@email.com; Allam, Srinivasa Rao, E-mail: cgiridhar84@gmail.com, E-mail: aloksharan@email.com; Satyanarayana, S. V. M., E-mail: cgiridhar84@gmail.com, E-mail: aloksharan@email.com; Sharan, Alok, E-mail: cgiridhar84@gmail.com, E-mail: aloksharan@email.com [Department of Physics, Pondicherry University, Puducherry-605014 (India)

    2014-10-15

    We present the study of the optical diffraction pattern of one and two-dimensional gratings with defects, designed using desktop pc and printed on OHP sheet using laser printer. Gratings so prepared, using novel low cost technique provides good visual aid in teaching. Diffraction pattern of the monochromatic light (632.8nm) from the grating so designed is similar to that of x-ray diffraction pattern of crystal lattice with point defects in one and two-dimensions. Here both optical and x-ray diffractions are Fraunhofer. The information about the crystalline lattice structure and the defect size can be known.

  17. Optical response in a laser-driven quantum pseudodot system

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, D. Gul [Physics Department, Graduate School of Natural and Applied Sciences, Dokuz Eylül University, 35390 Izmir (Turkey); Sakiroglu, S., E-mail: serpil.sakiroglu@deu.edu.tr [Physics Department, Faculty of Science, Dokuz Eylül University, 35390 Izmir (Turkey); Ungan, F.; Yesilgul, U. [Department of Optical Engineering, Faculty of Technology, Cumhuriyet University, 58140 Sivas (Turkey); Kasapoglu, E. [Physics Department, Faculty of Science, Cumhuriyet University, 58140 Sivas (Turkey); Sari, H. [Department of Primary Education, Faculty of Education, Cumhuriyet University, 58140 Sivas (Turkey); Sokmen, I. [Physics Department, Faculty of Science, Dokuz Eylül University, 35390 Izmir (Turkey)

    2017-03-15

    We investigate theoretically the intense laser-induced optical absorption coefficients and refractive index changes in a two-dimensional quantum pseudodot system under an uniform magnetic field. The effects of non-resonant, monochromatic intense laser field upon the system are treated within the framework of high-frequency Floquet approach in which the system is supposed to be governed by a laser-dressed potential. Linear and nonlinear absorption coefficients and relative changes in the refractive index are obtained by means of the compact-density matrix approach and iterative method. The results of numerical calculations for a typical GaAs quantum dot reveal that the optical response depends strongly on the magnitude of external magnetic field and characteristic parameters of the confinement potential. Moreover, we have demonstrated that the intense laser field modifies the confinement and thereby causes remarkable changes in the linear and nonlinear optical properties of the system.

  18. Optical response in a laser-driven quantum pseudodot system

    International Nuclear Information System (INIS)

    Kilic, D. Gul; Sakiroglu, S.; Ungan, F.; Yesilgul, U.; Kasapoglu, E.; Sari, H.; Sokmen, I.

    2017-01-01

    We investigate theoretically the intense laser-induced optical absorption coefficients and refractive index changes in a two-dimensional quantum pseudodot system under an uniform magnetic field. The effects of non-resonant, monochromatic intense laser field upon the system are treated within the framework of high-frequency Floquet approach in which the system is supposed to be governed by a laser-dressed potential. Linear and nonlinear absorption coefficients and relative changes in the refractive index are obtained by means of the compact-density matrix approach and iterative method. The results of numerical calculations for a typical GaAs quantum dot reveal that the optical response depends strongly on the magnitude of external magnetic field and characteristic parameters of the confinement potential. Moreover, we have demonstrated that the intense laser field modifies the confinement and thereby causes remarkable changes in the linear and nonlinear optical properties of the system.

  19. Micro Sampling System for Highly Radioactive Specimen by Laser Ablation

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sun Ho; Ha, Yeong Keong; Han, Ki Chul; Park, Yang Soon; Jee, Kwang Yong; Kim, Won Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2005-03-15

    Shielded laser ablation system composed of laser system, image analyser, XYZ translator with motion controller, ablation chamber, manipulator and various optics was designed. Nd:YAG laser which can be tunable from 1064 nm to 266 nm was selected as light source. CCD camera(< x 200) was chosen to analyze a crater less than 50 un in diameter. XYZ translator was composed of three linear stage which can travel 50 w with a minimum movement of 1 {mu}m and motion controller. Before the performance test, each part of system was optically aligned. To perform the ablation test, the specimen was ablated by 50 {mu}m interval and observed by image analyser The shape of crater was almost round, indicating laser beam has homogeneous energy distribution. The resolution and magnification of image system were compatible with the design.

  20. Optical design of high power excimer laser system

    International Nuclear Information System (INIS)

    Zhang Yongsheng; Zhao Jun; Ma Lianying; Yi Aiping; Liu Jingru

    2011-01-01

    Image relay and angular multiplexing,which should be considered together in the design of high power excimer laser system, is reviewed. It's important to select proper illumination setup and laser beam shaping techniques. Given the complex and special angular multiplexing scheme in high power excimer laser systems, some detailed conceptual layout schemes are given in the paper. After a brief description of lens array and reflective telescope objective, which combine the incoming beams to a common focus, a new schematic layout which uses the final targeting optics and one optical delay line array, to realize multiplexing and de-multiplexing simultaneously is first proposed in the paper. (authors)

  1. Laser Transmitters for the optical link systems used in CMS

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    In the CMS experiment of the now new flagship LHC optical links will be used for the tracker readout system. One part of this components will be semiconductor laser (~50.000 !!!), named correctly: 1310 nm InGaAsP (DCPBH-MQW) edge-emitting laser. They are foreseen as transmitter in the Tx Hybrid part of the optical link system.

  2. Interferogram reduction and interpretation as applied to the optical analysis of the 10 kJ LASL laser fusion system

    International Nuclear Information System (INIS)

    Viswanathan, V.K.; Hall, W.S.; Liberman, I.; Lawrence, G.

    1978-01-01

    The LASL 10 kJ Eight-Beam CO 2 Laser Fusion System, currently under construction, has approximately one hundred optical elements per beam. The nominal system is diffraction limited and degradations in performance are primarily caused by imperfect components as well as alignment errors. Consequently, analysis and predictions for the system are very much dependent on the proper description of the imperfect components. The approach taken at LASL has been to characterize the components interferometrically. Interferograms of the various components are made at the 633 nm He--Ne wavelength. Detailed results of the analysis for one complete leg of the eight-beam system is presented

  3. Quantum cascade lasers, systems, and applications in Europe

    Science.gov (United States)

    Lambrecht, Armin

    2005-03-01

    Since the invention of the Quantum Cascade Laser (QCL) a decade ago an impressive progress has been achieved from first low temperature pulsed laser emission to continuous wave operation at room temperature. Distributed feedback (DFB) lasers working in pulsed mode at ambient temperatures and covering a broad spectral range in the mid infrared (MIR) are commercially available now. For many industrial applications e.g. automotive exhaust control and process monitoring, laser spectroscopy is an established technique, generally using near infrared (NIR) diode lasers. However, the mid infrared (MIR) spectral region is of special interest because of much stronger absorption lines compared to NIR. The status of QCL devices, system development and applications is reviewed. Special emphasis is given to the situation in Europe where a remarkable growth of QCL related R&D can be observed.

  4. Demonstration of Laser Cutting System for Tube Specimen

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Y. G.; Kim, G. S.; Heo, G. S.; Baik, S. J.; Kim, H. M.; Ahn, S. B. [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The oxide layer removal system was also developed because the oxide layer on the surface of the irradiated fuel cladding and components interrupted the applying the electric current during the processing. However, it was found that the mechanical testing data of the irradiated specimens with removal of oxide layer was less reliable than the specimens with oxide layer . The laser cutting system using Nd:YAG with fiber optic beam delivery has great potential in material processing applications of the irradiated fuel cladding and components due to non-contact process. Thus, the oxide layer doesn't interrupt the fabrication process during the laser cutting system. In the present study, the laser cutting system was designed to fabricate the mechanical testing specimens from the unirradiated fuel cladding with and without oxide. The feasibility of the laser cutting system was demonstrated for the fabrication of various types of unirradiated specimens. The effect of surface oxide layer was also investigated for machining process of the zirlo fuel cladding and it was found that laser beam machining could be a useful tool to fabricate the specimens with surface oxide layer. Based on the feasibility studies and demonstration, the design of the laser cutting machine for fully or partially automatic and remotely operable system will be proposed and made.

  5. Optical system for UV-laser technological equipment

    Science.gov (United States)

    Fedosov, Yuri V.; Romanova, Galina E.; Afanasev, Maxim Ya.

    2017-09-01

    Recently there has been an intensive development of intelligent industrial equipment that is highly automated and can be rapidly adjusted for certain details. This equipment can be robotics systems, automatic wrappers and markers, CNC machines and 3D printers. The work equipment considered is the system for selective curing of photopolymers using a UV-laser and UV-radiation in such equipment that leads to additional technical difficulties. In many cases for transporting the radiation from the laser to the point processed, a multi-mirror system is used: however, such systems are usually difficult to adjust. Additionally, such multi-mirror systems are usually used as a part of the equipment for laser cutting of metals using high-power IR-lasers. For the UV-lasers, using many mirrors leads to crucial radiation losses because of many reflections. Therefore, during the development of the optical system for technological equipment using UV-laser we need to solve two main problems: to transfer the radiation for the working point with minimum losses and to include the system for controlling/handling the radiation spot position. We introduce a system for working with UV-lasers with 450mW of power and a wavelength of 0.45 μm based on a fiber system. In our modelling and design, we achieve spot sizes of about 300 μm, and the designed optical and mechanical systems (prototypes) were manufactured and assembled. In this paper, we present the layout of the technological unit, the results of the theoretical modelling of some parts of the system and some experimental results.

  6. X-ray diffraction studies of Pompeian wall paintings using synchrotron radiation and dedicated laboratory made systems

    International Nuclear Information System (INIS)

    Duran, A.; Castaing, J.; Walter, P.

    2010-01-01

    The full identification of artwork materials requires not only elemental analysis but also structural information of the compounds as provided by X-ray diffraction (XRD). This is easily done when taking samples (or micro-samples) from artworks. However, there is an increasing interest in performing non-destructive studies that require adapted XRD systems. Comparative study of synchrotron high-resolution X-ray powder diffraction (SR-HRPD) and laboratory non-destructive systems (portable XRD and micro-XRD) is the main objective of this work. There are no qualitative differences among the three systems as for detected phases in the Pompeian wall paintings that were studied, except in the case of minority phases which only were detected by SR-HRPD. The identified pigments were goethite, hematite, cinnabar, glauconite, Pompeian blue, together with calcite, dolomite and aragonite. Synchrotron XRD diagrams show better resolution than the others. In general, the peak widths in the diagrams obtained with the portable XRD system are similar to those obtained by micro-diffraction equipment. Factors such as residual divergence of X-ray sources, incidence angle and slit or collimator size are discussed in relation with the quality of XRD diagrams. (orig.)

  7. Secondary waste characteristics and ITS filtration system on laser cutting

    Energy Technology Data Exchange (ETDEWEB)

    Hara, Kunio; Miyao, Hidehiko [Research Association for Facility Decommissioning (RANDEC), Tokai, Ibaraki (Japan); Nakazawa, Masaharu [Tokyo Univ. (Japan); Kataoka, Shinichi; Nagura, Yasumi; Saiki, Hideo [Mitsubishi Heavy Industries Ltd., Tokyo (Japan)

    2001-03-01

    Technology of dismantling nuclear facilities has been developing in various fields for its evaluation and dismantling system. RANDEC has been studying remote dismantling system for highly activated equipments such as core internals with a laser using optical fiber. Recently a high power YAG laser having the advantage of application for remote dismantling on thick metallic material is the stage for practical use, and narrow kerf can bring the reduction of secondary waste as well. The present paper describes the experimental results and discussion on the laser cutting, including the secondary waste characteristics and its filtration system using the YAG laser. This study has been performed on consignment to RANDEC from the Science and Technology Agency of Japan. (author)

  8. Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

    Science.gov (United States)

    Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

    2016-02-23

    A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

  9. System of laser pump and synchrotron radiation probe microdiffraction to investigate optical recording process

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, Nobuhiro; Fukuyama, Yoshimitsu; Osawa, Hitoshi [Research and Utilization Division, Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Kimura, Shigeru [Research and Utilization Division, Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Japan Science and Technology Agency, CREST, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); Ito, Kiminori; Tanaka, Yoshihito [RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Matsunaga, Toshiyuki; Kojima, Rie; Hisada, Kazuya; Tsuchino, Akio; Birukawa, Masahiro [R and D Division, Panasonic Corporation, 3-4 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237 (Japan); Yamada, Noboru [Department of Materials Science and Engineering, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto, Kyoto 606-8501 (Japan); Sekiguchi, Koji; Fujiie, Kazuhiko; Kawakubo, Osamu [Advanced Optical Storage Development Department, Advanced Device Technology Platform, Sony Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa 243-0014 (Japan); Takata, Masaki [Research and Utilization Division, Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Department of Advanced Materials Science, School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan)

    2013-06-15

    We have developed a system of laser-pump and synchrotron radiation probe microdiffraction to investigate the phase-change process on a nanosecond time scale of Ge{sub 2}Sb{sub 2}Te{sub 5} film embedded in multi-layer structures, which corresponds to real optical recording media. The measurements were achieved by combining (i) the pump-laser system with a pulse width of 300 ps, (ii) a highly brilliant focused microbeam with wide peak-energy width ({Delta}E/E {approx} 2%) made by focusing helical undulator radiation without monochromatization, and (iii) a precise sample rotation stage to make repetitive measurements. We successfully detected a very weak time-resolved diffraction signal by using this system from 100-nm-thick Ge{sub 2}Sb{sub 2}Te{sub 5} phase-change layers. This enabled us to find the dependence of the crystal-amorphous phase change process of the Ge{sub 2}Sb{sub 2}Te{sub 5} layers on laser power.

  10. An in situ diffraction study of a solid oxide fuel cell system

    DEFF Research Database (Denmark)

    Sörby, L.; Poulsen, F.W.; Poulsen, H.F.

    1998-01-01

    The design of a synchrotron diffraction experiment on a working SOFC air-electrode is outlined. A large number of diffraction data sets were collected successfully from LSM/YSZ/Ag cells under different polarization states at 850 degrees C. Systematic changes are observed in lattice parameters...... and FWHM's for the LSM phase when the cell is polarized. The peak positions for the YSZ electrode are unchanged throughout the entire experiment. This is the first experimental evidence that oxygen stoichiometry in LSM is strongly influenced by the electrochemical reactions which take place. The cell...... parameters increase under reducing conditions, due to a decrease in the oxygen content of the LSM. All observed changes seem to be reversible....

  11. Improvement of laser irradiation uniformity in GEKKO XII glass laser system

    International Nuclear Information System (INIS)

    Miyanaga, Noriaki; Matsuoka, Shinichi; Ando, Akinobu; Amano, Shinji; Nakatsuka, Masahiro; Kanabe, Tadashi; Jitsuno, Takahisa; Nakai, Sadao

    1995-01-01

    The uniform laser irradiation is one of key issues in the direct drive laser fusion research. The several key technologies for the uniform laser irradiation are reported. This paper includes the uniformity performance as a result of the introduction of the random phase plate, the partially coherent light and the beam smoothing by spectral dispersion into the New Gekko XI glass laser system. Finally the authors summarize the overall irradiation uniformity on the spherical target surface by considering the power imbalance effect. The technologies developed for the beam smoothing and the power balance control enable them to achieve the irradiation nonuniformities of around 1% level for a foot pulse and of a few % for a main drive pulse, respectively

  12. Power Measurements for Microvision, Inc., Aircrew Integrated Helmet System Scanning Laser Helmet-Mounted Display

    National Research Council Canada - National Science Library

    Rash, Clarence

    2002-01-01

    ...) technology based on scanning lasers. Under this program, Microvision, Inc., Bothell, Washington, has developed a scanning laser HMD prototype for use with the Aircrew Integrated Helmet System (AIHS...

  13. Residual strain in the Nb-H system measured by selected area diffraction (SAD)

    International Nuclear Information System (INIS)

    Bulhoes, I.A.M.; Akune, K.; Pinatti, Dyonisio G.

    1981-07-01

    Various specimens of Nb were annealed in vacuum of 10 -3 torr for four hours at 1770 0 K. These speciments were doped with hydrogen up to 1000 ppm by weight and then were analyzed selected area diffraction. The line resolution of the electron channelling pattern was meassured for the specimens with different hydrogen content. These measurements, combined with the measurement of density, permitted one to estimate the residual strain caused by hydrogen. (Author) [pt

  14. Integral staggered point-matching method for millimeter-wave reflective diffraction gratings on electron cyclotron heating systems

    International Nuclear Information System (INIS)

    Xia, Donghui; Huang, Mei; Wang, Zhijiang; Zhang, Feng; Zhuang, Ge

    2016-01-01

    Highlights: • The integral staggered point-matching method for design of polarizers on the ECH systems is presented. • The availability of the integral staggered point-matching method is checked by numerical calculations. • Two polarizers are designed with the integral staggered point-matching method and the experimental results are given. - Abstract: The reflective diffraction gratings are widely used in the high power electron cyclotron heating systems for polarization strategy. This paper presents a method which we call “the integral staggered point-matching method” for design of reflective diffraction gratings. This method is based on the integral point-matching method. However, it effectively removes the convergence problems and tedious calculations of the integral point-matching method, making it easier to be used for a beginner. A code is developed based on this method. The calculation results of the integral staggered point-matching method are compared with the integral point-matching method, the coordinate transformation method and the low power measurement results. It indicates that the integral staggered point-matching method can be used as an optional method for the design of reflective diffraction gratings in electron cyclotron heating systems.

  15. Integral staggered point-matching method for millimeter-wave reflective diffraction gratings on electron cyclotron heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Donghui [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Huang, Mei [Southwestern Institute of Physics, 610041 Chengdu (China); Wang, Zhijiang, E-mail: wangzj@hust.edu.cn [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China); Zhang, Feng [Southwestern Institute of Physics, 610041 Chengdu (China); Zhuang, Ge [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, 430074 Wuhan (China)

    2016-10-15

    Highlights: • The integral staggered point-matching method for design of polarizers on the ECH systems is presented. • The availability of the integral staggered point-matching method is checked by numerical calculations. • Two polarizers are designed with the integral staggered point-matching method and the experimental results are given. - Abstract: The reflective diffraction gratings are widely used in the high power electron cyclotron heating systems for polarization strategy. This paper presents a method which we call “the integral staggered point-matching method” for design of reflective diffraction gratings. This method is based on the integral point-matching method. However, it effectively removes the convergence problems and tedious calculations of the integral point-matching method, making it easier to be used for a beginner. A code is developed based on this method. The calculation results of the integral staggered point-matching method are compared with the integral point-matching method, the coordinate transformation method and the low power measurement results. It indicates that the integral staggered point-matching method can be used as an optional method for the design of reflective diffraction gratings in electron cyclotron heating systems.

  16. Diffraction radiation from relativistic particles

    CERN Document Server

    Potylitsyn, Alexander Petrovich; Strikhanov, Mikhail Nikolaevich; Tishchenko, Alexey Alexandrovich

    2010-01-01

    This book deals with diffraction radiation, which implies the boundary problems of electromagnetic radiation theory. Diffraction radiation is generated when a charged particle moves in a vacuum near a target edge. Diffraction radiation of non-relativistic particles is widely used to design intense emitters in the cm wavelength range. Diffraction radiation from relativistic charged particles is important for noninvasive beam diagnostics and design of free electron lasers based on Smith-Purcell radiation which is diffraction radiation from periodic structures. Different analytical models of diffraction radiation and results of recent experimental studies are presented in this book. The book may also serve as guide to classical electrodynamics applications in beam physics and electrodynamics. It can be of great use for young researchers to develop skills and for experienced scientists to obtain new results.

  17. Diffraction radiation from relativistic particles

    International Nuclear Information System (INIS)

    Potylitsyn, Alexander Petrovich; Ryazanov, Mikhail Ivanovich; Strikhanov, Mikhail Nikolaevich; Tishchenko, Alexey Alexandrovich

    2010-01-01

    This book deals with diffraction radiation, which implies the boundary problems of electromagnetic radiation theory. Diffraction radiation is generated when a charged particle moves in a vacuum near a target edge. Diffraction radiation of non-relativistic particles is widely used to design intense emitters in the cm wavelength range. Diffraction radiation from relativistic charged particles is important for noninvasive beam diagnostics and design of free electron lasers based on Smith-Purcell radiation which is diffraction radiation from periodic structures. Different analytical models of diffraction radiation and results of recent experimental studies are presented in this book. The book may also serve as guide to classical electrodynamics applications in beam physics and electrodynamics. It can be of great use for young researchers to develop skills and for experienced scientists to obtain new results. (orig.)

  18. Rotating and standing waves in a diffractive nonlinear optical system with delayed feedback under O(2) Hopf bifurcation

    Science.gov (United States)

    Budzinskiy, S. S.; Razgulin, A. V.

    2017-08-01

    In this paper we study one-dimensional rotating and standing waves in a model of an O(2)-symmetric nonlinear optical system with diffraction and delay in the feedback loop whose dynamics is governed by a system of coupled delayed parabolic equation and linear Schrodinger-type equation. We elaborate a two-step approach: transition to a rotating coordinate system to obtain the profiles of the waves as small parameter expansions and the normal form technique to study their qualitative dynamic behavior and stability. Theoretical results stand in a good agreement with direct computer simulations presented.

  19. miniPixD : a compact sample analysis system which combines X-ray imaging and diffraction

    International Nuclear Information System (INIS)

    Moss, Robert; Crews, Chiaki; Speller, Robert; Wilson, Matthew

    2017-01-01

    This paper introduces miniPixD : a new, compact system that utilises transmission X-ray imaging and X-ray diffraction (XRD) to locate and identify materials of interest within an otherwise opaque volume. The system and the embodied techniques have utility in security screening, medical diagnostics, non-destructive testing (NDT) and quality assurance (QA). This paper outlines the design of the system including discussion on the choice of components and presents some data from relevant samples which are compared to other energy dispersive and angular dispersive XRD techniques.

  20. Neutronics of Laser Fission-Fusion Systems

    International Nuclear Information System (INIS)

    Velarde, G.

    1976-01-01

    Neutronics of Fission-Fusion microsystems inertially confined by Lasers are analysed by transport calculation, both stationary (DTF, TIHOC) and time dependent (TDA, TIHEX), discussing the results obtained for the basic parameters of the fission process (multiplication factor, neutron generation time and Rossi-∞). (Author) 14 refs

  1. Nonlinear propagation in fusion laser systems

    International Nuclear Information System (INIS)

    Bliss, E.S.; Glass, A.J.; Glaze, J.A.

    1977-11-01

    This report was assembled to provide a brief review of the historical development of the study of self-focusing and nonlinear light propagation and its impact on the design of large, Nd-glass lasers for fusion research. No claim to completeness is made, but we feel that the enclosed summary does not miss many of the major developments in the field

  2. Neutronics of Laser Fission-Fusion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Velarde, G

    1976-07-01

    Neutronics of Fission-Fusion microsystems inertially confined by Lasers are analysed by transport calculation, both stationary (DTF, TIHOC) and time dependent (TDA, TIHEX), discussing the results obtained for the basic parameters of the fission process (multiplication factor, neutron generation time and Rossi-{infinity}). (Author) 14 refs.

  3. Efficient TEA CO2 laser based coating removal system

    CSIR Research Space (South Africa)

    Prinsloo, FJ

    2007-04-01

    Full Text Available stream_source_info Prinsloo_2007.pdf.txt stream_content_type text/plain stream_size 11617 Content-Encoding UTF-8 stream_name Prinsloo_2007.pdf.txt Content-Type text/plain; charset=UTF-8 Efficient TEA CO2 laser based... by keeping energy density below the damage threshold. The advantage of a pulsed TEA CO2 laser system is that a laser frequency and temporal profile can be chosen to maximize paint removal and concurrently minimize substrate damage. To achieve...

  4. Fiber laser master oscillators for optical synchronization systems

    Energy Technology Data Exchange (ETDEWEB)

    Winter, A.

    2008-04-15

    New X-ray free electron lasers (e.g. the European XFEL) require a new generation of synchronization system to achieve a stability of the FEL pulse, such that pump-probe experiments can fully utilize the ultra-short pulse duration (50 fs). An optical synchronization system has been developed based on the distribution of sub-ps optical pulses in length-stabilized fiber links. The synchronization information is contained in the precise repetition frequency of the optical pulses. In this thesis, the design and characterization of the laser serving as laser master oscillator is presented. An erbium-doped mode-locked fiber laser was chosen. Amplitude and phase noise were measured and record-low values of 0.03 % and 10 fs for the frequency range of 1 kHz to the Nyquist frequency were obtained. Furthermore, an initial proof-of-principle experiment for the optical synchronization system was performed in an accelerator environment. In this experiment, the fiber laser wase phase-locked to a microwave reference oscillator and a 500 meter long fiber link was stabilized to 12 fs rms over a range of 0.1 Hz to 20 kHz. RF signals were obtained from a photodetector without significant degradation at the end of the link. Furthermore, the laser master oscillator for FLASH was designed and is presently in fabrication and the initial infrastructure for the optical synchronization system was setup. (orig.)

  5. Fiber laser master oscillators for optical synchronization systems

    International Nuclear Information System (INIS)

    Winter, A.

    2008-04-01

    New X-ray free electron lasers (e.g. the European XFEL) require a new generation of synchronization system to achieve a stability of the FEL pulse, such that pump-probe experiments can fully utilize the ultra-short pulse duration (50 fs). An optical synchronization system has been developed based on the distribution of sub-ps optical pulses in length-stabilized fiber links. The synchronization information is contained in the precise repetition frequency of the optical pulses. In this thesis, the design and characterization of the laser serving as laser master oscillator is presented. An erbium-doped mode-locked fiber laser was chosen. Amplitude and phase noise were measured and record-low values of 0.03 % and 10 fs for the frequency range of 1 kHz to the Nyquist frequency were obtained. Furthermore, an initial proof-of-principle experiment for the optical synchronization system was performed in an accelerator environment. In this experiment, the fiber laser wase phase-locked to a microwave reference oscillator and a 500 meter long fiber link was stabilized to 12 fs rms over a range of 0.1 Hz to 20 kHz. RF signals were obtained from a photodetector without significant degradation at the end of the link. Furthermore, the laser master oscillator for FLASH was designed and is presently in fabrication and the initial infrastructure for the optical synchronization system was setup. (orig.)

  6. Evaluation of crystalline changes and resistance to demineralization of the surface of human dental enamel treated with Er:YAG laser and fluoride using x-ray diffraction analysis and Vickers microhardness

    Science.gov (United States)

    Behroozibakhsh, Marjan; Shahabi, Sima; Ghavami-Lahiji, Mehrsima; Sadeghian, Safura; Sadat Faal Nazari, Neda

    2018-06-01

    This study aimed to investigate the changes in crystalline structure and resistance to demineralization of human dental surface enamel treated with erbium-doped yttrium aluminium garnet laser (Er:YAG) laser and fluoride. The enamel surfaces were divided into four groups according to the treatment process including, (L): irradiated with Er:YAG; (F): treated with acidulated phosphate fluoride gel (LF): Pre-irradiated surfaces with Er:YAG subjected to acidulated phosphate fluoride gel and (FL): laser irradiation was performed on the fluoridated enamel surface. Before and after the treatment procedure, the samples were evaluated using X-ray diffraction, scanning electron microscope (SEM) and the Vickers microhardness test. The surface microhardness values also were measured after a pH-cycling regime and acid challenge. The a-axis of all lased groups was contracted after treatment procedure. Measurement of the area under the peaks showed the highest crysallinity in the FL group. The hardness values of all laser treated samples significantly reduced after treatment procedure compared to the F group (p  ⩽  0.001). The morphological observations showed remarkable changes on the lased enamel surfaces including cracks, craters and exposed prisms. These findings suggest, irradiation of the Er:YAG laser accompanying with fluoride application can induce some beneficial crystalline changes regarding the acid-resistance properties of enamel, however, the craters and cracks produced by laser irradiation can promote enamel demineralization and consequently the positive effects of the Er:YAG laser will be eliminated.

  7. Acousto-optic laser projection systems for displaying TV information

    Energy Technology Data Exchange (ETDEWEB)

    Gulyaev, Yu V [V.A.Kotel' nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Moscow (Russian Federation); Kazaryan, M A [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Mokrushin, Yu M [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (Russian Federation); Shakin, O V [Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg (Russian Federation)

    2015-04-30

    This review addresses various approaches to television projection imaging on large screens using lasers. Results are presented of theoretical and experimental studies of an acousto-optic projection system operating on the principle of projecting an image of an entire amplitude-modulated television line in a single laser pulse. We consider characteristic features of image formation in such a system and the requirements for its individual components. Particular attention is paid to nonlinear distortions of the image signal, which show up most severely at low modulation signal frequencies. We discuss the feasibility of improving the process efficiency and image quality using acousto-optic modulators and pulsed lasers. Real-time projectors with pulsed line imaging can be used for controlling high-intensity laser radiation. (review)

  8. Acousto-optic laser projection systems for displaying TV information

    International Nuclear Information System (INIS)

    Gulyaev, Yu V; Kazaryan, M A; Mokrushin, Yu M; Shakin, O V

    2015-01-01

    This review addresses various approaches to television projection imaging on large screens using lasers. Results are presented of theoretical and experimental studies of an acousto-optic projection system operating on the principle of projecting an image of an entire amplitude-modulated television line in a single laser pulse. We consider characteristic features of image formation in such a system and the requirements for its individual components. Particular attention is paid to nonlinear distortions of the image signal, which show up most severely at low modulation signal frequencies. We discuss the feasibility of improving the process efficiency and image quality using acousto-optic modulators and pulsed lasers. Real-time projectors with pulsed line imaging can be used for controlling high-intensity laser radiation. (review)

  9. Acousto-optic laser projection systems for displaying TV information

    Science.gov (United States)

    Gulyaev, Yu V.; Kazaryan, M. A.; Mokrushin, Yu M.; Shakin, O. V.

    2015-04-01

    This review addresses various approaches to television projection imaging on large screens using lasers. Results are presented of theoretical and experimental studies of an acousto-optic projection system operating on the principle of projecting an image of an entire amplitude-modulated television line in a single laser pulse. We consider characteristic features of image formation in such a system and the requirements for its individual components. Particular attention is paid to nonlinear distortions of the image signal, which show up most severely at low modulation signal frequencies. We discuss the feasibility of improving the process efficiency and image quality using acousto-optic modulators and pulsed lasers. Real-time projectors with pulsed line imaging can be used for controlling high-intensity laser radiation.

  10. Mid-IR laser system for advanced neurosurgery

    Science.gov (United States)

    Klosner, M.; Wu, C.; Heller, D. F.

    2014-03-01

    We present work on a laser system operating in the near- and mid-IR spectral regions, having output characteristics designed to be optimal for cutting various tissue types. We provide a brief overview of laser-tissue interactions and the importance of controlling certain properties of the light beam. We describe the principle of operation of the laser system, which is generally based on a wavelength-tunable alexandrite laser oscillator/amplifier, and multiple Raman conversion stages. This configuration provides robust access to the mid-IR spectral region at wavelengths, pulse energies, pulse durations, and repetition rates that are attractive for neurosurgical applications. We summarize results for ultra-precise selective cutting of nerve sheaths and retinas with little collateral damage; this has applications in procedures such as optic-nerve-sheath fenestration and possible spinal repair. We also report results for cutting cornea, and dermal tissues.

  11. Evaluation of Poisson's ratio and Young's modulus of nitride films by combining grazing incidence X-ray diffraction and laser curvature techniques

    International Nuclear Information System (INIS)

    Chen, H.-Y.; Chen, J.-H.; Lu, F.-H.

    2007-01-01

    Measurements of Poisson's ratio and the Young's modulus of thin films have been problematic. In this work, evaluation of both Poisson's ratio and Young's modulus is conducted using grazing incidence X-ray diffraction combined with measurement of the induced stress. Poisson's ratio was evaluated from analysis of the X-ray diffraction data to obtain a strain-cos 2 α.sin 2 ψ plot. Moreover, the Young's modulus of the films could be also calculated from that plot as well as from the residual stress, which could be determined by a measurement of stress induced substrate curvature. The ternary nitride TiAlN is used as a model system for the evaluation. The films, prepared by cathodic arc plasma deposition, exhibited a strong (111) preferred orientation and a composition corresponding to Ti 0.6 Al 0.4 N. The measured Poisson's ratio and the Young's modulus of the films were 0.143 ± 0.003 and 310 ± 20 GPa, respectively, which are comparable to those reported in the literature

  12. Diffraction dissociation

    International Nuclear Information System (INIS)

    Abarbanel, H.

    1972-01-01

    An attempt is made to analyse the present theoretical situation in the field of diffraction scattering. Two not yet fully answered questions related with a typical diffraction process AB→CD, namely: what is the structure of the transition matrix elements, and what is the structure of the exchange mechanism responsible for the scattering, are formulated and various proposals for answers are reviewed. Interesting general statement that the products (-1)sup(J)P, where J and P are respectively spin and parity, is conserved at each vertex has been discussed. The exchange mechanism in diffractive scattering has been considered using the language of the complex J-plane as the most appropriate. The known facts about the exchange mechanism are recalled and several routs to way out are proposed. The idea to consider the moving pole and associated branch points as like a particle and the associated two and many particle unitarity cuts is described in more details. (S.B.)

  13. Optical design and analysis of carbon dioxide laser fusion systems using interferometry and fast Fourier transform techniques

    International Nuclear Information System (INIS)

    Viswanathan, V.K.

    1979-01-01

    The optical design and analysis of the LASL carbon dioxide laser fusion systems required the use of techniques that are quite different from the currently used method in conventional optical design problems. The necessity for this is explored and the method that has been successfully used at Los Alamos to understand these systems is discussed with examples. This method involves characterization of the various optical components in their mounts by a Zernike polynomial set and using fast Fourier transform techniques to propagate the beam, taking diffraction and other nonlinear effects that occur in these types of systems into account. The various programs used for analysis are briefly discussed

  14. Wavelength stabilized multi-kW diode laser systems

    Science.gov (United States)

    Köhler, Bernd; Unger, Andreas; Kindervater, Tobias; Drovs, Simon; Wolf, Paul; Hubrich, Ralf; Beczkowiak, Anna; Auch, Stefan; Müntz, Holger; Biesenbach, Jens

    2015-03-01

    We report on wavelength stabilized high-power diode laser systems with enhanced spectral brightness by means of Volume Holographic Gratings. High-power diode laser modules typically have a relatively broad spectral width of about 3 to 6 nm. In addition the center wavelength shifts by changing the temperature and the driving current, which is obstructive for pumping applications with small absorption bandwidths. Wavelength stabilization of high-power diode laser systems is an important method to increase the efficiency of diode pumped solid-state lasers. It also enables power scaling by dense wavelength multiplexing. To ensure a wide locking range and efficient wavelength stabilization the parameters of the Volume Holographic Grating and the parameters of the diode laser bar have to be adapted carefully. Important parameters are the reflectivity of the Volume Holographic Grating, the reflectivity of the diode laser bar as well as its angular and spectral emission characteristics. In this paper we present detailed data on wavelength stabilized diode laser systems with and without fiber coupling in the spectral range from 634 nm up to 1533 nm. The maximum output power of 2.7 kW was measured for a fiber coupled system (1000 μm, NA 0.22), which was stabilized at a wavelength of 969 nm with a spectral width of only 0.6 nm (90% value). Another example is a narrow line-width diode laser stack, which was stabilized at a wavelength of 1533 nm with a spectral bandwidth below 1 nm and an output power of 835 W.

  15. Diffraction attraction

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Elastic scattering – when colliding particles 'bounce' off each other like billiard balls – has always had a special interest for high energy physicists. While its simplicity makes for deep analogies with classical ideas like diffraction, its jbtle details also test our understanding of the intricate inner mechanisms which drive particle interactions. With a new stock of elastic scattering data now available thanks to experiments at the CERN proton-antiproton Collider, and with studies at higher energies imminent or planned, some seventy physicists gathered in the magnificent chateau at Blois, France, for a 'Workshop on Elastic and Diffractive Scattering at the Collider and Beyond'

  16. Diffractive scattering

    CERN Document Server

    De Wolf, E.A.

    2002-01-01

    We discuss basic concepts and properties of diffractive phenomena in soft hadron collisions and in deep-inelastic scattering at low Bjorken-x. The paper is not a review of the rapidly developing field but presents an attempt to show in simple terms the close inter-relationship between the dynamics of high-energy hadronic and deep-inelastic diffraction. Using the saturation model of Golec-Biernat and Wusthoff as an example, a simple explanation of geometrical scaling is presented. The relation between the QCD anomalous multiplicity dimension and the Pomeron intercept is discussed.

  17. Diffractive Scattering

    International Nuclear Information System (INIS)

    Wolf, E.A. de

    2002-01-01

    We discuss basic concepts and properties of diffractive phenomena in soft hadron collisions and in deep-inelastic scattering at low Bjorken - x. The paper is not a review of the rapidly developing field but presents an attempt to show in simple terms the close inter-relationship between the dynamics of high-energy hadronic and deep-inelastic diffraction. Using the saturation model of Golec-Biernat and Wuesthoff as an example, a simple explanation of geometrical scaling is presented. The relation between the QCD anomalous multiplicity dimension and the Pomeron intercept is discussed. (author)

  18. Diffraction attraction

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1986-03-15

    Elastic scattering – when colliding particles 'bounce' off each other like billiard balls – has always had a special interest for high energy physicists. While its simplicity makes for deep analogies with classical ideas like diffraction, its jbtle details also test our understanding of the intricate inner mechanisms which drive particle interactions. With a new stock of elastic scattering data now available thanks to experiments at the CERN proton-antiproton Collider, and with studies at higher energies imminent or planned, some seventy physicists gathered in the magnificent chateau at Blois, France, for a 'Workshop on Elastic and Diffractive Scattering at the Collider and Beyond'.

  19. A comparative study with a 755 nm picosecond Alexandrite laser with a diffractive lens array and a 532 nm/1064 nm Nd:YAG with a holographic optic.

    Science.gov (United States)

    Tanghetti Md, Emil; Jennings, John

    2018-01-01

    This study was performed to better understand the cutaneous effects of using a fractional picosecond laser at 755 nm with a diffractive lens array and a picosecond Nd:YAG laser at 532 mn and 1064 nm with a holographic optic. We characterized the injuries created by these devices on skin clinically and histologically over 24 hours. With this information we modeled the effects of these devices on a cutaneous target. Eight patients, representing Fitzpatrick skin types I-VI, were treated on their backs with a picosecond Alexandrite laser with a diffractive lens array, as well as a picosecond Nd:YAG laser at 532 nm and 1064 nm with a holographic optic. Photographs were taken 15 minutes and 24 hours after treatments. Punch biopsies were obtained at 24 hours and examined histologically. Treatment with the picosecond Nd:YAG laser at both 532 nm and 1064 nm with the holographic optic revealed erythema and small scatted areas of petechial hemorrhage areas immediately and in many cases at 24 hours after treatment. The 755 nm picosecond Alexandrite laser with diffractive lens array produced erythema immediately after treatment, which largely dissipated 24 hours later. Histologies revealed intra-epidermal vacuoles with all three wavelengths. Fractional picosecond Nd:YAG laser at 532 nm and 1064 nm with the holographic optic showed focal areas of dermal and intra-epidermal hemorrhage with areas of vascular damage in some patients. This study demonstrates that both fractional picosecond devices produce vacuoles in the skin, which are most likely due to areas of laser induced optical breakdown (LIOB). In the patients (skin type II-IV) we observed scatter areas of hemorrhage in the skin, due to vascular damage with the 532 nm and 1064 nm, but not with 755 nm wavelengths. Lasers Surg. Med. 50:37-44, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Development of a Laser Induced Fluorescence (LIF) System with a Tunable Diode Laser

    International Nuclear Information System (INIS)

    Woo, Hyun Jong; Do, Jeong Jun; You, Hyun Jong; Choi, Geun Sik; Lee, Myoung Jae; Chung, Kyu Sun

    2005-01-01

    The Laser Induced Fluorescence (LIF) is known as one of the most powerful techniques for measurements of ion velocity distribution function (IVDF) and ion temperature by means of Doppler broadening and Doppler shift. The dye lasers are generally used for LIF system with 611.66 nm (in vac.) for Ar ion, the low power diode laser was also proposed by Severn et al with the wavelength of 664.55 nm and 668.61 nm (in vac.) for Ar ion. Although the diode laser has the disadvantages of low power and small tuning range, it can be used for LIF system at the low temperature plasmas. A tunable diode laser with 668.614 nm of center wavelength and 10 GHz mode hop free tuning region has been used for our LIF system and it can be measured the ion temperature is up to 1 eV. The ion temperature and velocity distribution function have been measured with LaB6 plasma source, which is about 0.23 eV with Ar gas and 2.2 mTorr working pressure

  1. Optimized laser system for decontamination of painted surfaces

    International Nuclear Information System (INIS)

    Champonnois, F.; Lascoutouna, C.; Long, H.; Thro, P.Y.; Mauchien, P.

    2010-01-01

    Laser systems have long been seen as potentially very interesting for removing contamination from surfaces. The main expected advantages are the possibility of remote process and the absence of secondary waste. However these systems were unable to find their way to an industrial deployment due to the lack of reliability of the laser and the difficulty to satisfactory collect the (contaminated) ablated matter. In this contribution we report on a compact, reliable and efficient laser decontaminating system called ASPILASERO. It is adapted to the constraints bound to a nuclear environment. It takes advantages of the recent progress made by the fibre lasers which have now a lifetime longer than 20000 hours without maintenance. The collecting system collects all the removed matter (gases and aerosols) on nuclear grade filters. The fully automated system has been successfully tested on a vertical wall of a stopped nuclear installation. It has demonstrated an efficiency of 1 m 2 /hr which is in the same order of other classical techniques but with a much lower quantity of waste and the ability to work continuously without human intervention. Measurements performed after the laser treatment have shown that the contamination was completely removed by removing the paint and that this contamination was not re-deposited elsewhere on the wall. The system will also be used in highly contaminated hot cells to decrease the radiation and allow maintenance or refurbishing in safe working conditions. (authors)

  2. Development of tunable flashlamp excited dye laser system

    International Nuclear Information System (INIS)

    Bhanthumnavin, V.; Apikitmata, S.; Kochareon, P.

    1991-01-01

    A tunable flashlamp excited dye laser (FEDL) was successfully developed for the first time in Thailand by Thai scientists at KMIT Thonburi (Bangmod). The Rhodamine 6G dissolved in ethyl alcohol was utilized as a laser medium and circulated by a pump through a laser head. The dye cuvette had an inner diameter of 4.0 mm and was 90 mm long. The cavity mirrors M 1 , and M 2 were concave mirrors with reflectivities of 100% and 73% respectively. A power supply of 0-20 kV and current of 0-50 mA charged a capacitor of 0.3 μ f at 10-15 kV which was then discharged via a spark gap through the flashlamp. The output laser wavelengths was tunable from λ = 550-640 nm. It is the first FEDL system, locally developed, which has a tunable wavelength for the laser output. The laser pulse width is about 1.0 μs with energy of 20 mJ and peak power pf 20 KW. The repetition rate of the laser is 1/15 Hz. (author). 14 refs, 7 figs

  3. Development of an integrated automated retinal surgical laser system.

    Science.gov (United States)

    Barrett, S F; Wright, C H; Oberg, E D; Rockwell, B A; Cain, C; Rylander, H G; Welch, A J

    1996-01-01

    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. Preliminary testing on rhesus primate subjects have been accomplished with the CW argon laser and also the ultrashort pulse 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. Several interesting areas of study have developed in integrating the two subsystems: 1) "doughnut" shaped lesions that occur under certain combinations of laser power, spot size, and irradiation time complicating measurements of central lesion reflectance, 2) the optimal retinal field of view (FOV) to achieve both tracking and lesion parameter control, and 3) development of a hybrid analog/digital tracker using confocal reflectometry to achieve retinal tracking speeds of up to 100 dgs. This presentation will discuss these design issues of this clinically significant prototype system. Details of the hybrid prototype system are provided in "Hybrid Eye Tracking for Computer-Aided Retinal Surgery" at this conference. The paper will close with remaining technical hurdles to clear prior to testing the full-up clinical prototype system.

  4. A noncontact laser system for measuring soil surface topography

    International Nuclear Information System (INIS)

    Huang, C.; White, I.; Thwaite, E.G.; Bendeli, A.

    1988-01-01

    Soil surface topography profoundly influences runoff hydrodynamics, soil erosion, and surface retention of water. Here we describe an optical noncontact system for measuring soil surface topography. Soil elevation is measured by projecting a laser beam onto the surface and detecting the position of the interception point. The optical axis of the detection system is oriented at a small angle to the incident beam. A low-power HeNe (Helium-Neon) laser is used as the laser source, a photodiode array is used as the laser image detector and an ordinary 35-mm single lens reflex camera provides the optical system to focus the laser image onto the diode array. A wide spectrum of measurement ranges (R) and resolutions are selectable, from 1 mm to 1 m. These are determined by the laser-camera distance and angle, the focal length of the lens, and the sensing length of the diode array and the number of elements (N) contained in the array. The resolution of the system is approximately R/2N. We show for the system used here that this resolution is approximately 0.2%. In the configuration selected, elevation changes of 0.16 mm could be detected over a surface elevation range of 87 mm. The sampling rate of the system is 1000 Hz, which permits soil surfaces to be measured at speeds of up to 1 m s −1 with measurements taken at 1-mm spacing. Measurements of individual raindrop impacts on the soil and of soil surfaces before and after rain show the versatility of the laser surface profiler, which has applications in studies of erosion processes, surface storage and soil trafficability

  5. Field-Testing of an Active Laser Tracking System

    Science.gov (United States)

    Markov, V.; Khiznyak, A.; Woll, D.; Liu, S.

    Comprehensive space surveillance demands a more accurate technique in tracking multi-dimensional state vector (3D coordinate, velocity, vibration, etc.) of the space objects. RF radiometric techniques typically can not provide the needed accuracy, while passive optical (and laser) tracking systems can provide distance to the object and its angular position, but not a direct reading of velocity, the parameter of primary importance for space object tracking and characterization. Addressing this problem with active optical tracking techniques is challenging because of the great distances involved, the high velocity of the satellites, and the optical aberrations induced by the atmosphere. We have proposed a phase conjugation based laser tracking concept, and accomplished the first version of design and engineering of a prototype for an Active Laser Tracking System (ALTS). In its current state the ALTS is capable to demonstrate the very basics operational principles of the proposed active tracking technique. We then performed a number of experiments to prove operational capabilities of this prototype both at MetroLaser's lab environment and at Edwards AFB Test Range. In its current architecture the ALTS is comprised of two laser cavities, Master and Slave that are coupled through a Phase Conjugate Mirror (PCM) formed in a non-linear medium (NLM) set at Master laser cavity. By pumping NLM and forming PCM, Master laser establishes the cavities coupling mode and injects the photons in the slave cavity. It is essential that the specific features of the PCM not only serve to couple ALTS cavities, but also serves to compensate optical aberrations of the ALTS (gain media and optical elements of the laser resonator). Due to its ability to compensate optical aberrations, phase conjugate resonators are capable of sustaining oscillation with a remote target as an output coupler. The entire system comprises of several modules, including a laser, emitting/receiving telescope, gimbal

  6. Development of a multi-beam laser ultrasonic inspection system and its application on flaw sizing

    International Nuclear Information System (INIS)

    Chivavibul, Pornthep; Lin, Shan; Fukutomi, Hiroyuki; Higuchi, Sadao; Ogata, Takashi; Fukuchi, Tetsuo

    2006-01-01

    Laser ultrasonic technique is a powerful tool for non-contact, nondestructive testing of materials. It is expected to apply to where the conventional ultrasonic technique is not applicable. However, this technique suffers from low sensitivity. In order to overcome this shortcoming, a multi-beam laser ultrasonic system was developed to increase signal-to-noise ratio (SNR) and steer beam direction. The system consisted of eight pulsed Nd:YAG lasers used for ultrasonic generation, and a two-wave mixing interferometer with a long-pulsed Nd:YAG used for ultrasonic detection. Spatial and temporal control of the firing of the individual lasers permitted the generation of both phased array single pulse and narrow-band ultrasonic signals. The performance of developed system was verified using aluminum specimens with the wave generation in a slight ablation mode. A significant increase in sensitivity was obtained, with an increase in signal amplitude with no change in noise level. In the narrow band case, tone bursts were successfully generated in both surface and bulk waves. Beam steering of bulk waves was also performed, and the directivity was confirmed by visualization using a conventional transducer. The developed system was applied to flaw sizing using two techniques: shadow and short-path of diffraction (SPOD), using aluminum specimens with 2-mm, 5-mm, 8-mm slit depths. The shadow technique accurately measured the 5- and 8-mm slits, but not the 2-mm slit. The SPOD technique, carried out using a 5-MHz normal longitudinal transducer as a detector instead of TWN interferometer, accurately measured slits in all specimens with an error less than 0.5 mm. (author)

  7. Uses of ORACLE in the Nova Laser Control System

    International Nuclear Information System (INIS)

    McGuigan, D.L.

    1983-01-01

    The Nova Laser System is a large-scale fusion experiment being constructed at the Lawrence Livermore National Laboratory. Modern control system technology is required to efficiently manage the thousands of devices needed to operate the system. In order to reduce the requirements on the operations staff, much of the system is being automated. This requires a significant knowledge base including frequently used system configurations and device parameters. We will be using ORACLE to provide this information to the control system. To insure the control-system integrity, ORACLE will be used to maintain information about the control-system software. This information will be used to document the system as well as help track down problems. ORACLE will also be used to maintain data on the system performance. This data will be analyzed to optimize the laser performance and point out when maintenance is required

  8. A 1-kJ KrF laser system for laser fusion research

    International Nuclear Information System (INIS)

    Owadano, Y.; Okuda, I.; Tanimoto, M.; Matsumoto, Y.; Yaoita, A.; Komeiji, S.; Yano, M.

    1987-01-01

    Ultraviolet laser light has several advantages in coupling with a laser fusion target, and the KrF laser is considered to be a promising candidate for the driver because of its short wavelength, high overall efficiency, and scalability to a megajoule class system. The Electrotechnical Laboratory is developing a 1-kJ class KrF laser system to perform target-shooting experiments in the 10/sup 13/-10/sup 15/-W/cm/sup 2/, 10-20-ns range and to investigate the possibility of a compact laser fusion driver which operates at a high pumping density and high laser power density. Based on the pulsed-power technology used in Amp2 and the characteristics of the Kr-rich mixture measured, Amp3 was designed to operate at high optical power density with a Kr-rich mixture. Amp3 has four PFLs charged by a single 40-kJ Marx generator and four e-beam diodes (550 kV, 4 Ω) arranged cylindrically around the laser cell. The active volume is 660 cm/sup 2/ (29 cm in diameter) X 1 m, and 2-atm Kr is pumped at a density of 1.9 MW/cm/sup 3/. Output energy of 1 kJ is expected at an intrinsic efficiency of 8.3% and overall efficiency of 2.5%. Output energy fluence is 1.5 J/cm/sup 2/ (15 MW/cm/sup 2/) on average, which is lower than the damage threshold of our fully reflecting AR coatings (>3 J/cm/sup 2/)

  9. Development of Blue Laser Direct-Write Lithography System

    Directory of Open Access Journals (Sweden)

    Hao-Wen Chang

    2012-01-01

    Full Text Available The optical lithography system researched in this study adopted the laser direct-write lithography technology with nano-positioning stage by using retailing blue ray optical pickup head contained 405nm wavelength and 0.85 numerical aperture of focus lens as the system lighting source. The system employed a photodiode received the focusing error signal reflected by the glass substrate to identify specimen position and automatic focused control with voice coil motor. The pattern substrate was loaded on a nano-positioning stage; input pattern path automatically and collocate with inner program at the same time. This research has successfully developed a blue laser lithography process system. The single spot size can be narrowed down to 3.07 μm and the linewidth is 3.3μm, time of laser control can reach to 450 ns and the exposure pattern can be controlled by program as well.

  10. In-situ X-ray diffraction system using sources and detectors at fixed angular positions

    Science.gov (United States)

    Gibson, David M [Voorheesville, NY; Gibson, Walter M [Voorheesville, NY; Huang, Huapeng [Latham, NY

    2007-06-26

    An x-ray diffraction technique for measuring a known characteristic of a sample of a material in an in-situ state. The technique includes using an x-ray source for emitting substantially divergent x-ray radiation--with a collimating optic disposed with respect to the fixed source for producing a substantially parallel beam of x-ray radiation by receiving and redirecting the divergent paths of the divergent x-ray radiation. A first x-ray detector collects radiation diffracted from the sample; wherein the source and detector are fixed, during operation thereof, in position relative to each other and in at least one dimension relative to the sample according to a-priori knowledge about the known characteristic of the sample. A second x-ray detector may be fixed relative to the first x-ray detector according to the a-priori knowledge about the known characteristic of the sample, especially in a phase monitoring embodiment of the present invention.

  11. University of Hawaii Lure Observatory. [lunar laser ranging system construction

    Science.gov (United States)

    Carter, W. E.; Williams, J. D.

    1973-01-01

    The University of Hawaii's Institute for Astronomy is currently constructing a lunar laser ranging observatory at the 3050-meter summit of Mt. Haleakala, Hawaii. The Nd YAG laser system to be employed provides three pulses per second, each pulse being approximately 200 picoseconds in duration. The energy contained in one pulse at 5320 A lies in the range from 250 to 350 millijoules. Details of observatory construction are provided together with transmitter design data and information concerning the lunastat, the feed telescope, the relative pointing system, the receiver, and the event timer system.

  12. Fiber optic coherent laser radar 3d vision system

    International Nuclear Information System (INIS)

    Sebastian, R.L.; Clark, R.B.; Simonson, D.L.

    1994-01-01

    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 of 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. Measurement system with high accuracy for laser beam quality.

    Science.gov (United States)

    Ke, Yi; Zeng, Ciling; Xie, Peiyuan; Jiang, Qingshan; Liang, Ke; Yang, Zhenyu; Zhao, Ming

    2015-05-20

    Presently, most of the laser beam quality measurement system collimates the optical path manually with low efficiency and low repeatability. To solve these problems, this paper proposed a new collimated method to improve the reliability and accuracy of the measurement results. The system accuracy controlled the position of the mirror to change laser beam propagation direction, which can realize the beam perpendicularly incident to the photosurface of camera. The experiment results show that the proposed system has good repeatability and the measuring deviation of M2 factor is less than 0.6%.

  14. Laser fusion systems design study. Final technical report

    International Nuclear Information System (INIS)

    1975-06-01

    This study investigated: (1) the formulation and evaluation of an alignment system to accomplish pointing, focusing, centering and translation for the 20-arm SHIVA laser, (2) the formulation and evaluation of concepts for the correction of static phase distortions introduced by the accumulated optical elements in the laser chains, (3) the formulation and evaluation of concepts for the correction of optical path length differences between the arms of the SHIVA system, and (4) the conceptual design of appropriate control system hardware. (U.S.)

  15. Method of laser beam coding for control systems

    Science.gov (United States)

    Pałys, Tomasz; Arciuch, Artur; Walczak, Andrzej; Murawski, Krzysztof

    2017-08-01

    The article presents the method of encoding a laser beam for control systems. The experiments were performed using a red laser emitting source with a wavelength of λ = 650 nm and a power of P ≍ 3 mW. The aim of the study was to develop methods of modulation and demodulation of the laser beam. Results of research, in which we determined the effect of selected camera parameters, such as image resolution, number of frames per second on the result of demodulation of optical signal, is also shown in the paper. The experiments showed that the adopted coding method provides sufficient information encoded in a single laser beam (36 codes with the effectiveness of decoding at 99.9%).

  16. Requirements and new materials for fusion laser systems

    International Nuclear Information System (INIS)

    Stokowski, S.E.; Weber, M.J.; Saroyan, R.A.; Hagen, W.F.

    1977-10-01

    Higher focusable power in neodymium glass fusion lasers can be obtained through the use of new materials with lower nonlinear index (n 2 ) and better energy storage capabilities than the presently employed silicate glass. Silicate, phosphate, fluorophosphate, and beryllium fluoride glasses are discussed in terms of fusion laser requirements, particularly those for the proposed Nova laser. Examples of the variation in spectroscopic and optical properties obtainable with compositional changes are given. Results of a system evaluation of potential laser materials show that fluorophosphate glasses have many of the desired properties for use in Nova. These glasses are now being cast in large sizes (30-cm diameter) and will be tested in prototype amplifiers in 1978

  17. Requirements and new materials for fusion laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Stokowski, S.E.; Weber, M.J.; Saroyan, R.A.; Hagen, W.F.

    1977-10-01

    Higher focusable power in neodymium glass fusion lasers can be obtained through the use of new materials with lower nonlinear index (n/sub 2/) and better energy storage capabilities than the presently employed silicate glass. Silicate, phosphate, fluorophosphate, and beryllium fluoride glasses are discussed in terms of fusion laser requirements, particularly those for the proposed Nova laser. Examples of the variation in spectroscopic and optical properties obtainable with compositional changes are given. Results of a system evaluation of potential laser materials show that fluorophosphate glasses have many of the desired properties for use in Nova. These glasses are now being cast in large sizes (30-cm diameter) and will be tested in prototype amplifiers in 1978.

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

    Energy Technology Data Exchange (ETDEWEB)

    Yakovlev, I V [Institute of Applied Physics, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation)

    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)

  19. Apparatus, system, and method for laser-induced breakdown spectroscopy

    Science.gov (United States)

    Effenberger, Jr., Andrew J; Scott, Jill R; McJunkin, Timothy R

    2014-11-18

    In laser-induced breakdown spectroscopy (LIBS), an apparatus includes a pulsed laser configured to generate a pulsed laser signal toward a sample, a constructive interference object and an optical element, each located in a path of light from the sample. The constructive interference object is configured to generate constructive interference patterns of the light. The optical element is configured to disperse the light. A LIBS system includes a first and a second optical element, and a data acquisition module. The data acquisition module is configured to determine an isotope measurement based, at least in part, on light received by an image sensor from the first and second optical elements. A method for performing LIBS includes generating a pulsed laser on a sample to generate light from a plasma, generating constructive interference patterns of the light, and dispersing the light into a plurality of wavelengths.

  20. Recent developments in retinal lasers and delivery systems

    Directory of Open Access Journals (Sweden)

    Naresh Kumar Yadav

    2014-01-01

    Full Text Available Photocoagulation is the standard of care for several ocular disorders and in particular retinal conditions. Technology has offered us newer lasing mediums, wavelengths and delivery systems. Pattern scan laser in proliferative diabetic retinopathy and diabetic macular edema allows laser treatment that is less time consuming and less painful. Now, it is possible to deliver a subthreshold micropulse laser that is above the threshold of biochemical effect but below the threshold of a visible, destructive lesion thereby preventing collateral damage. The advent of solid-state diode yellow laser allows us to treat closer to the fovea, is more effective for vascular structures and offers a more uniform effect in patients with light or irregular fundus pigmentation. Newer retinal photocoagulation options along with their advantages is discussed in this review.

  1. BENCHMARKING MOBILE LASER SCANNING SYSTEMS USING A PERMANENT TEST FIELD

    Directory of Open Access Journals (Sweden)

    H. Kaartinen

    2012-07-01

    Full Text Available The objective of the study was to benchmark the geometric accuracy of mobile laser scanning (MLS systems using a permanent test field under good coverage of GNSS. Mobile laser scanning, also called mobile terrestrial laser scanning, is currently a rapidly developing area in laser scanning where laser scanners, GNSS and IMU are mounted onboard a moving vehicle. MLS can be considered to fill the gap between airborne and terrestrial laser scanning. Data provided by MLS systems can be characterized with the following technical parameters: a point density in the range of 100-1000 points per m2 at 10 m distance, b distance measurement accuracy of 2-5 cm, and c operational scanning range from 1 to 100 m. Several commercial, including e.g. Riegl, Optech and others, and some research mobile laser scanning systems surveyed the test field using predefined driving speed and directions. The acquired georeferenced point clouds were delivered for analyzing. The geometric accuracy of the point clouds was determined using the reference targets that could be identified and measured from the point cloud. Results show that in good GNSS conditions most systems can reach an accuracy of 2 cm both in plane and elevation. The accuracy of a low cost system, the price of which is less than tenth of the other systems, seems to be within a few centimetres at least in ground elevation determination. Inaccuracies in the relative orientation of the instruments lead to systematic errors and when several scanners are used, in multiple reproductions of the objects. Mobile laser scanning systems can collect high density point cloud data with high accuracy. A permanent test field suits well for verifying and comparing the performance of different mobile laser scanning systems. The accuracy of the relative orientation between the mapping instruments needs more attention. For example, if the object is seen double in the point cloud due to imperfect boresight calibration between two

  2. A supervisor system for computer aided laser machining

    International Nuclear Information System (INIS)

    Mukherjee, J.K.

    1990-01-01

    Lasers achieve non divergent beam of short wavelength energy which can propagate through normal atmosphere with little divergence and can be focused on very fine points. The final high energy per unit area on target is highly localised and suitable for various types of machining at high speeds. The most notable factor is that this high energy spot can be located precisely using light-weight optical components. The laser-machining is very amenable to environmental conditions unlike electron beam and other techniques. Precision cutting and welding of nuclear materials in normal or non oxidising atmosphere can be done using this fairly easily. To achieve these objectives, development of a computer controlled laser machining system has been undertaken. The development project aims at building a computer aided machine with indegenous controller and medium power laser suitable for cutting, welding, and marking. This paper describes the integration of the various computer aided functions, spanning over the full range, from job-defining to final finished part-delivary, in computer aided laser machining. Various innovative features of the system that render it suitable for laser tool development as well as for special machining applications with user-friendliness have been covered. (author). 5 refs., 5 figs

  3. The design of laser atmosphere transmission characteristic measurement system based on virtual instrument

    Science.gov (United States)

    Zhang, Laixian; Sun, Huayan; Xu, Jiawen

    2010-10-01

    The laser atmosphere transmission characteristic affects the use of laser in engineering greatly. This paper designed a laser atmosphere transmission characteristic measurement system based on LabVIEW software, a product of NI. The system acquires laser spacial distribution by means of controlling NI image acquisition card and CCD through PCI, controls oscillograph to acquire laser time domain distribution through Ethernet and controls power meter to acquire energy of laser through RS-232. It processes the data acquired and analyses the laser atmosphere transmission characteristic using Matlab, which is powerful in data processing, through software interface. It provided a new way to study the laser atmosphere transmission characteristic.

  4. Applications of OALCLV in the high power laser systems

    Science.gov (United States)

    Huang, Dajie; Fan, Wei; Cheng, He; Wei, Hui; Wang, Jiangfeng; An, Honghai; Wang, Chao; Cheng, Yu; Xia, Gang; Li, Xuechun; Lin, Zunqi

    2017-10-01

    This paper introduces the recent development of our integrated optical addressed spatial light modulator and its applications in the high power laser systems. It can be used to convert the incident beam into uniform beam for high energy effiency, or it can realize special distribution to meet the requirements of physical experiment. The optical addressing method can avoid the problem of the black matrix effect of the electric addressing device. Its transmittance for 1053nm light is about 85% and the aperture of our device has reached 22mm× 22mm. As a transmissive device, it can be inserted into the system without affecting the original optical path. The applications of the device in the three laser systems are introduced in detail in this paper. In the SGII-Up laser facility, this device demonstrates its ability to shape the output laser beam of the fundamental frequency when the output energy reaches about 2000J. Meanwhile, there's no change in the time waveform and far field distribution. This means that it can effectively improve the capacity of the maximum output energy. In the 1J1Hz Nd-glass laser system, this device has been used to improve the uniformity of the output beam. As a result, the PV value reduces from 1.4 to 1.2, which means the beam quality has been improved effectively. In the 9th beam of SGII laser facility, the device has been used to meet the requirements of sampling the probe light. As the transmittance distribution of the laser beam can be adjusted, the sampling spot can be realized in real time. As a result, it's easy to make the sampled spot meet the requirements of physics experiment.

  5. Laser rangefinders for autonomous intelligent cruise control systems

    Science.gov (United States)

    Journet, Bernard A.; Bazin, Gaelle

    1998-01-01

    THe purpose of this paper is to show to what kind of application laser range-finders can be used inside Autonomous Intelligent Cruise Control systems. Even if laser systems present good performances the safety and technical considerations are very restrictive. As the system is used in the outside, the emitted average output power must respect the rather low level of 1A class. Obstacle detection or collision avoidance require a 200 meters range. Moreover bad weather conditions, like rain or fog, ar disastrous. We have conducted measurements on laser rangefinder using different targets and at different distances. We can infer that except for cooperative targets low power laser rangefinder are not powerful enough for long distance measurement. Radars, like 77 GHz systems, are better adapted to such cases. But in case of short distances measurement, range around 10 meters, with a minimum distance around twenty centimeters, laser rangefinders are really useful with good resolution and rather low cost. Applications can have the following of white lines on the road, the target being easily cooperative, detection of vehicles in the vicinity, that means car convoy traffic control or parking assistance, the target surface being indifferent at short distances.

  6. Operative and economic evaluation of a 'Laser Printer Multimodality' System

    International Nuclear Information System (INIS)

    Battaglia, G.; Moscatelli, G.; Maroldi, R.; Chiesa, A.

    1991-01-01

    The increasing application of digital techniques to diagnostic imaging is causing significant changes in several related activities, such as a reproduction of digital images on film. In the Department of Diagnostic Imaging of the University of Brescia, about 70% of the whole of images are produced by digital techniques; at present, most of these images are reproduced on film with a Multimodality System interfacing CT, MR, DSA, and DR units with a single laser printer. Our analysis evaluates the operative and economics aspects of image reproduction, by comparing the 'single cassette' multiformat Camera and the Laser Printer Multimodality SAystem. Our results point out the advantages obtained by reproducing images with a Laser Printer Multimodality System: outstanding quality, reproduction of multiple originals, and marked reduction in the time needed for both image archiving and film handling. The Laser Printer Multimodality System allows over 5 hours/day to be saved -that is to say the working day of an operator, who can be thus shifted to other functions. The important economic aspect of the reproduction of digital images on film proves the Laser Printer Multimodality System to have some advantage over Cameras

  7. Designing, modeling and controlling a novel autonomous laser weeding system

    DEFF Research Database (Denmark)

    Shahrak Nadimi, Esmaeil; Andersson, Kim Johan; Jørgensen, Rasmus Nyholm

    2009-01-01

      Abstract: in this paper, the process of designing and developing a novel laser weeding test setup is explained. The main purpose of designing this system was to simulate the dynamic field conditions of a mobile vehicle capable of targeting weeds. This system consists of a rig containing three...

  8. High Power laser power conditioning system new discharge circuit research

    CERN Document Server

    Li Yi; Peng Han Sheng; Zhou Pei Zhang; Zheng Wan Guo; Guo Lang Fu; Chen Li Hua; Chen De Hui; Lai Gui You; Luan Yong Ping

    2002-01-01

    The new discharge circuit of power conditioning system for high power laser is studied. The theoretical model of the main discharge circuit is established. The pre-ionization circuit is studied in experiment. In addition, the explosion energy of the new large xenon lamp is successfully measured. The conclusion has been applied to 4 x 2 amplifier system

  9. Semiconductor Mode-Locked Lasers for Optical Communication Systems

    DEFF Research Database (Denmark)

    Yvind, Kresten

    2003-01-01

    The thesis deals with the design and fabrication of semiconductor mode-locked lasers for use in optical communication systems. The properties of pulse sources and characterization methods are described as well as requirements for application in communication systems. Especially, the importance of...

  10. CSIR National Laser Centre develops a high speed OCT system

    CSIR Research Space (South Africa)

    Sharma, Ameeth

    2016-11-01

    Full Text Available . The system, which is not limited to this application, can image a large volume (25mm x 25mm x 11mm) and resultant 3-D images (512 x 512 x 2048 pixels) are acquired in less than three seconds. The heart of the system is a swept laser source and a two...

  11. High resolution Fresnel zone plate laser alignment system

    International Nuclear Information System (INIS)

    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

  12. Performance of a MOPA laser system for photocathode research

    NARCIS (Netherlands)

    Mols, R.F.X.A.M.; Mols, R.F.X.A.M.; Ernst, G.J.

    1994-01-01

    A Nd:YLF laser system with frequency doubled output is described. Several aspects concerning energy and stability of the pulses will be discussed. The system consists of a CW mode locked Nd:YLF oscillator and two double pass amplifiers having a total small signal gain of about a million which means

  13. Laser metrology and optic active control system for GAIA

    Science.gov (United States)

    D'Angelo, F.; Bonino, L.; Cesare, S.; Castorina, G.; Mottini, S.; Bertinetto, F.; Bisi, M.; Canuto, E.; Musso, F.

    2017-11-01

    The Laser Metrology and Optic Active Control (LM&OAC) program has been carried out under ESA contract with the purpose to design and validate a laser metrology system and an actuation mechanism to monitor and control at microarcsec level the stability of the Basic Angle (angle between the lines of sight of the two telescopes) of GAIA satellite. As part of the program, a breadboard (including some EQM elements) of the laser metrology and control system has been built and submitted to functional, performance and environmental tests. In the followings we describe the mission requirements, the system architecture, the breadboard design, and finally the performed validation tests. Conclusion and appraisals from this experience are also reported.

  14. Relay telescope for high power laser alignment system

    Science.gov (United States)

    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.

  15. The laser-based calibration system of delta spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Malakhov, A.I. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Anisimov, Yu.S. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Gmuca, S. [Inst. of Physics, SAS, Bratislava (Slovakia); Kizka, V.A. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Kliman, J. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Inst. of Physics, SAS, Bratislava (Slovakia); Krasnov, V.A. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Kurepin, A.B. [Inst. for Nuclear Research RAS, Moscow (Russian Federation); Kuznetsov, S.N. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Livanov, A.N. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Matousek, V. [Inst. of Physics, SAS, Bratislava (Slovakia); Morhac, M. [Inst. of Physics, SAS, Bratislava (Slovakia)]. E-mail: Miroslav.Morhac@savba.sk; Turzo, I. [Inst. of Physics, SAS, Bratislava (Slovakia)

    2006-10-15

    We present a report on a laser calibration system of DELTA spectrometer that has been designed and developed in the Laboratory of High Energies, JINR, Dubna. The system is intended for monitoring and continuous stabilization of the outputs of the detectors of the spectrometer. The UV nitrogen pulse laser along with optical filters, collection of optical fibers and plastic scintillators serving for conversion of UV light pulses to longer wavelength and for diffusion of the light beam to illuminate 300 photomultipliers are used. We stabilize the positions of laser peaks by corrections of high voltages of the corresponding photomultipliers. The proposed system allows one to accomplish the stabilization during the experiment with the use of the same electronics. The control software together with the first results from test runs are described as well.

  16. Picosecond high power laser systems and picosecond diagnostic technique in laser produced plasma

    International Nuclear Information System (INIS)

    Kuroda, Hiroto; Masuko, H.; Maekawa, Shigeru; Suzuki, Yoshiji; Sugiyama, Masaru.

    1979-01-01

    Highly repetitive, high power YAG and Glass laser systems have been developed and been successfully used for the studies of laser-plasma interactions. Various picosecond diagnostic techniques have been developed for such purposes in the regions from optical to X-ray frequency. Recently highly sensitive X-ray (1 - 10 KeV) streak camera for highly repetitive operations have been developed. Preliminary experiment shows the achievement of 28ps temporal resolution (100μm slit) and good sensitivity with detectable minimum number of 10E3-1KeV photons/shot/slit area. (author)

  17. Help system for control of JAERI FEL (Free Electron laser)

    International Nuclear Information System (INIS)

    Sugimoto, Masayoshi

    1993-01-01

    The control system of JAERI FEL (Free Electron Laser) has a help system to provide the information necessary to operate the machine and to develop the new user interface. As the control software is constructed on the MS-Windows 3.x, the hyper-text feature of the Windows help system can be accessed. It consists of three major parts: (1) on-line help, (2) full document, and (3) tutorial system. (author)

  18. Powder diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Hart, M.

    1995-12-31

    the importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer in Germany and, quite independently, by Hull in the US. Three distinct periods of evolution lead to ubiquitous application in many fields of science and technology. In the first period, until the mid-1940`s, applications were and developed covering broad categories of materials including inorganic materials, minerals, ceramics, metals, alloys, organic materials and polymers. During this formative period, the concept of quantitative phase analysis was demonstrated. In the second period there followed the blossoming of technology and commercial instruments became widely used. The history is well summarized by Parrish and by Langford and Loueer. By 1980 there were probably 10,000 powder diffractometers in routine use, making it the most widely used of all x-ray crystallographic instruments. In the third, present, period data bases became firmly established and sophisticated pattern fitting and recognition software made many aspects of powder diffraction analysis routine. High resolution, tunable powder diffractometers were developed at sources of synchrotron radiation. The tunability of the spectrum made it possible to exploit all the subtleties of x-ray spectroscopy in diffraction experiments.

  19. Powder diffraction

    International Nuclear Information System (INIS)

    Hart, M.

    1995-01-01

    The importance of x-ray powder diffraction as an analytical tool for phase identification of materials was first pointed out by Debye and Scherrer in Germany and, quite independently, by Hull in the US. Three distinct periods of evolution lead to ubiquitous application in many fields of science and technology. In the first period, until the mid-1940's, applications were and developed covering broad categories of materials including inorganic materials, minerals, ceramics, metals, alloys, organic materials and polymers. During this formative period, the concept of quantitative phase analysis was demonstrated. In the second period there followed the blossoming of technology and commercial instruments became widely used. The history is well summarized by Parrish and by Langford and Loueer. By 1980 there were probably 10,000 powder diffractometers in routine use, making it the most widely used of all x-ray crystallographic instruments. In the third, present, period data bases became firmly established and sophisticated pattern fitting and recognition software made many aspects of powder diffraction analysis routine. High resolution, tunable powder diffractometers were developed at sources of synchrotron radiation. The tunability of the spectrum made it possible to exploit all the subtleties of x-ray spectroscopy in diffraction experiments

  20. An All-Solid-State High Repetiton Rate Titanium:Sapphire Laser System For Resonance Ionization Laser Ion Sources

    Science.gov (United States)

    Mattolat, C.; Rothe, S.; Schwellnus, F.; Gottwald, T.; Raeder, S.; Wendt, K.

    2009-03-01

    On-line production facilities for radioactive isotopes nowadays heavily rely on resonance ionization laser ion sources due to their demonstrated unsurpassed efficiency and elemental selectivity. Powerful high repetition rate tunable pulsed dye or Ti:sapphire lasers can be used for this purpose. To counteract limitations of short pulse pump lasers, as needed for dye laser pumping, i.e. copper vapor lasers, which include high maintenance and nevertheless often only imperfect reliability, an all-solid-state Nd:YAG pumped Ti:sapphire laser system has been constructed. This could complement or even replace dye laser systems, eliminating their disadvantages but on the other hand introduce shortcomings on the side of the available wavelength range. Pros and cons of these developments will be discussed.