Science.gov

Sample records for beam optics

  1. Dual beam optical interferometer

    NASA Technical Reports Server (NTRS)

    Gutierrez, Roman C. (Inventor)

    2003-01-01

    A dual beam interferometer device is disclosed that enables moving an optics module in a direction, which changes the path lengths of two beams of light. The two beams reflect off a surface of an object and generate different speckle patterns detected by an element, such as a camera. The camera detects a characteristic of the surface.

  2. Beam optics test stand

    NASA Astrophysics Data System (ADS)

    Humphries, S., Jr.; Hess, G.

    1988-04-01

    The design and construction of the Beam Optics Test Stand (BOTS) is presented. A variety of computer compatible diagnostics has been developed to facilitate experiments. Extensive theoretical work is presented leading to the identification of two potential methods to correct aberrations in magnetic optics: biased grid arrays and space charge corrected solenoidal lenses. A series of experiments is presented which demonstrates, for the first time, the feasibility of space charge corrected optics.

  3. Primer on Beam Optics

    DTIC Science & Technology

    2007-11-02

    Inc. San Diego, California Table of Contents Page 1 . Introduction 1 1.1 Organization of Primer 1 1.2 Introduction to Neutral Particle Beam...Optical Systems 3 2. Fundamentals of Charged Particle Optics 10 2.1 Introduction 1 ° 2.2 Phase Space and Nonlinear Motion 10 2.3 Linear Maps 22 2.4...102 Figures Figure Pag© 1 . Generic Neutral Particle Beam Device 4 2. An orthogonal three dimensional coordinate system 11 3. Trajectory of a

  4. Optical beam jitter control

    NASA Astrophysics Data System (ADS)

    Watkins, R. Joseph; Chen, Hong-Jen; Agrawal, Brij N.; Shin, Young S.

    2004-06-01

    For several future imaging and communications spacecraft, a challenging area of technology development is the fine acquisition, tracking, and pointing (ATP) control of the spacecraft and its payload. For example, some spacecraft with large aperture(s) in the range of 10~30 m diameter requires a few arc-seconds accuracy, 10~15 nano-radians jitter, and a fast slewing rate to acquire the target. Furthermore these stringent requirements are at risk of great structure and control interactions. This paper we will focus on the control of optical beam jitter. A Laser Jitter Control (LJC) testbed has been constructed to test jitter algorithms. The testbed consists of two fast steering mirrors (FSM), three position sensing modules (PSM), one diode laser, and several beam splitters and mirrors, all on an isolated Newport optical bench. Jitter is injected with one FSM and the other FSM is used to control it. The jitter spectrum, representing the on-orbit spacecraft and beam jitter environment, contains not only narrow band noise due to rotating devices such as gyroscopes and reaction wheels but also broadband noise. The performance of a Wiener Filter-adaptive algorithm with ideal reference signal is established as the baseline for comparison of adaptive control methods in suppressing both broadband and narrowband disturbances. Specifically, the Least Mean Squares (LMS) approach and the Gradient Adaptive Lattice (GAL) approach are investigated during these experiments.

  5. Matching optics for Gaussian beams

    NASA Technical Reports Server (NTRS)

    Gunter, William D. (Inventor)

    1991-01-01

    A system of matching optics for Gaussian beams is described. The matching optics system is positioned between a light beam emitter (such as a laser) and the input optics of a second optics system whereby the output from the light beam emitter is converted into an optimum input for the succeeding parts of the second optical system. The matching optics arrangement includes the combination of a light beam emitter, such as a laser with a movable afocal lens pair (telescope) and a single movable lens placed in the laser's output beam. The single movable lens serves as an input to the telescope. If desired, a second lens, which may be fixed, is positioned in the beam before the adjustable lens to serve as an input processor to the movable lens. The system provides the ability to choose waist diameter and position independently and achieve the desired values with two simple adjustments not requiring iteration.

  6. Converging beam optical Fourier transforms

    NASA Astrophysics Data System (ADS)

    Puang-ngern, Srisuda; Almeida, Silverio P.

    1985-08-01

    The classical, most often used, system for performing the optical Fourier transform is by using parallel coherent beam illumination. Lenses used in this method can become quite costly. In this paper we present results obtained using converging beam illumination which is suitable for many applications and is less expensive than the parallel beam method. The input objects for which the Fourier transforms were made are transparencies of snowflakes.

  7. Optical tractor Bessel polarized beams

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.; Li, R. X.; Guo, L. X.; Ding, C. Y.

    2017-01-01

    Axial and transverse radiation force cross-sections of optical tractor Bessel polarized beams are theoretically investigated for a dielectric sphere with particular emphasis on the beam topological charge (or order), half-cone angle and polarization. The angular spectrum decomposition method (ASDM) is used to derive the non-paraxial electromagnetic (EM) field components of the Bessel beams. The multipole expansion method using vector spherical harmonics is utilized and appropriate beam-shape coefficients are derived in order to compute the radiation force cross-sections. The analysis has no limitation to a particular range of frequencies such that the Rayleigh, Mie or geometrical optics regimes can all be considered effectively using the present rigorous formalism. The focus of this investigation is to identify some of the tractor beam conditions so as to achieve retrograde motion of a dielectric sphere located arbitrarily in space. Numerical computations for the axial and transverse radiation force cross-sections are presented for linear, right-circular, radial, azimuthal and mixed polarizations of the individual plane waves forming the Bessel beams of zeroth- and first-order (with positive or negative helicity), respectively. As the sphere shifts off the beam's axis, the axial pulling (tractor) force is weakened. Moreover, the transverse radiation force cross-section field changes with the sphere's size factor ka (where k is the wavenumber and a is the sphere radius). Both stable and unstable equilibrium regions around the beam's axis are found, depending on the choice of ka and the half-cone angle α0. These results are particularly important in the development of emergent technologies for the photophoretic assembly of optically-engineered (meta)materials with designed properties using optical tractor (vortex) beams, particle manipulation, levitation and positioning, and other applications.

  8. Optical Beam-Shear Sensors

    NASA Technical Reports Server (NTRS)

    Martin, Stefan; Szwaykowski, Piotr

    2007-01-01

    A technique for measuring optical beam shear is based on collecting light from the four quadrants of the beam and comparing the optical power collected from each quadrant with that from the other three quadrants. As used here, "shear" signifies lateral displacement of a beam of light from a nominal optical axis. A sensor for implementing this technique consists of a modified focusing lens and a quad-cell photodetector, both centered on the nominal optical axis. The modification of the lens consists in cutting the lens into four sectors (corresponding to the four quadrants) by sawing along two orthogonal diameters, then reassembling the lens following either of two approaches described next. In one approach, the lens is reassembled by gluing the sectors back together. In the simplest variant of this approach, the kerf of the saw matches the spacing of the photodetector cells, so that the focus of each sector crosses the axis of symmetry to fall on the opposite photodetector cell (see figure). In another variant of this approach, the lens sectors are spaced apart to make their individual foci to fall on separate photodetector cells, without crossing the optical axis. In the case of a sufficiently wide beam, the modified lens could be replaced with four independent lenses placed in a square array, each focusing onto an independent photodetector

  9. Airy beam optical parametric oscillator

    NASA Astrophysics Data System (ADS)

    Aadhi, A.; Chaitanya, N. Apurv; Jabir, M. V.; Vaity, Pravin; Singh, R. P.; Samanta, G. K.

    2016-05-01

    Airy beam, a non-diffracting waveform, has peculiar properties of self-healing and self-acceleration. Due to such unique properties, the Airy beam finds many applications including curved plasma wave-guiding, micro-particle manipulation, optically mediated particle clearing, long distance communication, and nonlinear frequency conversion. However, many of these applications including laser machining of curved structures, generation of curved plasma channels, guiding of electric discharges in a curved path, study of nonlinear propagation dynamics, and nonlinear interaction demand Airy beam with high power, energy, and wavelength tunability. Till date, none of the Airy beam sources have all these features in a single device. Here, we report a new class of coherent sources based on cubic phase modulation of a singly-resonant optical parametric oscillator (OPO), producing high-power, continuous-wave (cw), tunable radiation in 2-D Airy intensity profile existing over a length >2 m. Based on a MgO-doped periodically poled LiNbO3 crystal pumped at 1064 nm, the Airy beam OPO produces output power more than 8 W, and wavelength tunability across 1.51–1.97 μm. This demonstration gives new direction for the development of sources of arbitrary structured beams at any wavelength, power, and energy in all time scales (cw to femtosecond).

  10. Airy beam optical parametric oscillator.

    PubMed

    Aadhi, A; Chaitanya, N Apurv; Jabir, M V; Vaity, Pravin; Singh, R P; Samanta, G K

    2016-05-04

    Airy beam, a non-diffracting waveform, has peculiar properties of self-healing and self-acceleration. Due to such unique properties, the Airy beam finds many applications including curved plasma wave-guiding, micro-particle manipulation, optically mediated particle clearing, long distance communication, and nonlinear frequency conversion. However, many of these applications including laser machining of curved structures, generation of curved plasma channels, guiding of electric discharges in a curved path, study of nonlinear propagation dynamics, and nonlinear interaction demand Airy beam with high power, energy, and wavelength tunability. Till date, none of the Airy beam sources have all these features in a single device. Here, we report a new class of coherent sources based on cubic phase modulation of a singly-resonant optical parametric oscillator (OPO), producing high-power, continuous-wave (cw), tunable radiation in 2-D Airy intensity profile existing over a length >2 m. Based on a MgO-doped periodically poled LiNbO3 crystal pumped at 1064 nm, the Airy beam OPO produces output power more than 8 W, and wavelength tunability across 1.51-1.97 μm. This demonstration gives new direction for the development of sources of arbitrary structured beams at any wavelength, power, and energy in all time scales (cw to femtosecond).

  11. Airy beam optical parametric oscillator

    PubMed Central

    Aadhi, A.; Chaitanya, N. Apurv; Jabir, M. V.; Vaity, Pravin; Singh, R. P.; Samanta, G. K.

    2016-01-01

    Airy beam, a non-diffracting waveform, has peculiar properties of self-healing and self-acceleration. Due to such unique properties, the Airy beam finds many applications including curved plasma wave-guiding, micro-particle manipulation, optically mediated particle clearing, long distance communication, and nonlinear frequency conversion. However, many of these applications including laser machining of curved structures, generation of curved plasma channels, guiding of electric discharges in a curved path, study of nonlinear propagation dynamics, and nonlinear interaction demand Airy beam with high power, energy, and wavelength tunability. Till date, none of the Airy beam sources have all these features in a single device. Here, we report a new class of coherent sources based on cubic phase modulation of a singly-resonant optical parametric oscillator (OPO), producing high-power, continuous-wave (cw), tunable radiation in 2-D Airy intensity profile existing over a length >2 m. Based on a MgO-doped periodically poled LiNbO3 crystal pumped at 1064 nm, the Airy beam OPO produces output power more than 8 W, and wavelength tunability across 1.51–1.97 μm. This demonstration gives new direction for the development of sources of arbitrary structured beams at any wavelength, power, and energy in all time scales (cw to femtosecond). PMID:27143582

  12. Fractal zone plate beam based optical tweezers

    PubMed Central

    Cheng, Shubo; Zhang, Xinyu; Ma, Wenzhuo; Tao, Shaohua

    2016-01-01

    We demonstrate optical manipulation with an optical beam generated by a fractral zone plate (FZP). The experimental results show that the FZP beam can simultaneously trap multiple particles positioned in different focal planes of the FZP beam, owing to the multiple foci and self-reconstruction property of the FZP beam. The FZP beam can also be used to construct three-dimensional optical tweezers for potential applications. PMID:27678305

  13. Apodization of beams in an optical interferometer

    NASA Technical Reports Server (NTRS)

    Ames, Lawrence L. (Inventor); Dutta, Kalyan (Inventor)

    2006-01-01

    An interferometry apparatus comprises one or more beam generators, a detector, and a plurality of optical paths along which one or more beams of light propagate. Disposed along at least one of the optical paths is an apodization mask to shape one of the beams.

  14. Optical chirped beam amplification and propagation

    DOEpatents

    Barty, Christopher P.

    2004-10-12

    A short pulse laser system uses dispersive optics in a chirped-beam amplification architecture to produce high peak power pulses and high peak intensities without the potential for intensity dependent damage to downstream optical components after amplification.

  15. Laser beam modeling in optical storage systems

    NASA Technical Reports Server (NTRS)

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

    1991-01-01

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

  16. Optical fiber antenna generating spiral beam shapes

    SciTech Connect

    Sarkar Pal, S.; Mondal, S. K. Kumar, R.; Akula, A.; Ghosh, R.; Bhatnagar, R.; Kumbhakar, D.

    2014-01-20

    A simple method is proposed here to generate vortex beam and spiral intensity patterns from a Gaussian source. It uses a special type of optical fiber antenna of aperture ∼80 nm having naturally grown surface curvature along its length. The antenna converts linearly polarized Gaussian beam into a beam with spiral intensity patterns. The experimentally obtained spiral patterns with single and double spiral arms manifest the orbital angular momentum, l = ±1, 2, carried by the output beam. Such beam can be very useful for optical tweezer, metal machining, and similar applications.

  17. Elegant Gaussian beams for enhanced optical manipulation

    SciTech Connect

    Alpmann, Christina Schöler, Christoph; Denz, Cornelia

    2015-06-15

    Generation of micro- and nanostructured complex light beams attains increasing impact in photonics and laser applications. In this contribution, we demonstrate the implementation and experimental realization of the relatively unknown, but highly versatile class of complex-valued Elegant Hermite- and Laguerre-Gaussian beams. These beams create higher trapping forces compared to standard Gaussian light fields due to their propagation changing properties. We demonstrate optical trapping and alignment of complex functional particles as nanocontainers with standard and Elegant Gaussian light beams. Elegant Gaussian beams will inspire manifold applications in optical manipulation, direct laser writing, or microscopy, where the design of the point-spread function is relevant.

  18. Space Optical Communications Using Laser Beam Amplification

    NASA Technical Reports Server (NTRS)

    Agrawal, Govind

    2015-01-01

    The Space Optical Communications Using Laser Beam Amplification (SOCLBA) project will provide a capability to amplify a laser beam that is received in a modulating retro-reflector (MRR) located in a satellite in low Earth orbit. It will also improve the pointing procedure between Earth and spacecraft terminals. The technology uses laser arrays to strengthen the reflected laser beam from the spacecraft. The results of first year's work (2014) show amplification factors of 60 times the power of the signal beam. MMRs are mirrors that reflect light beams back to the source. In space optical communications, a high-powered laser interrogator beam is directed from the ground to a satellite. Within the satellite, the beam is redirected back to ground using the MMR. In the MMR, the beam passes through modulators, which encode a data signal onto the returning beam. MMRs can be used in small spacecraft for optical communications. The SOCLBA project is significant to NASA and small spacecraft due to its application to CubeSats for optical data transmission to ground stations, as well as possible application to spacecraft for optical data transmission.

  19. Optical vortex beam generator at nanoscale level

    NASA Astrophysics Data System (ADS)

    Garoli, Denis; Zilio, Pierfrancesco; Gorodetski, Yuri; Tantussi, Francesco; de Angelis, Francesco

    2016-07-01

    Optical beams carrying orbital angular momentum (OAM) can find tremendous applications in several fields. In order to apply these particular beams in photonic integrated devices innovative optical elements have been proposed. Here we are interested in the generation of OAM-carrying beams at the nanoscale level. We design and experimentally demonstrate a plasmonic optical vortex emitter, based on a metal-insulator-metal holey plasmonic vortex lens. Our plasmonic element is shown to convert impinging circularly polarized light to an orbital angular momentum state capable of propagating to the far-field. Moreover, the emerging OAM can be externally adjusted by switching the handedness of the incident light polarization. The device has a radius of few micrometers and the OAM beam is generated from subwavelength aperture. The fabrication of integrated arrays of PVLs and the possible simultaneous emission of multiple optical vortices provide an easy way to the large-scale integration of optical vortex emitters for wide-ranging applications.

  20. Acousto-Optic Beam Steering Study

    DTIC Science & Technology

    1994-08-01

    8217111 INK $ 1 1 illl iII Ill i, R L-TR-94-121 !1!1Il t 11I1!I!11! ilI, / Final Technical Report August 1994 ACOUSTO - OPTIC BEAM STEERING STUDY Harris...contractual obligations or notices on a specific document require that it be returned. For i ..........I ,, ACOUSTO - OPTIC BEAM STEERING STUDY H. W...4. TITLE AND SUBTITLE 5. FUNDING NUMBERS ACOUSTO - OPTIC BEAM STEERING STUDY C - F30602-91-C-0131 PE - 63215C 6. AUTHOR(S) PR - 1405 TA - 02 H. W

  1. Electro-optic Waveguide Beam Deflector.

    DTIC Science & Technology

    beam deflection by variation in the electro - optic effect produced within the waveguide region in response to known or determinable magnitude variations in the electrical potential of an applied signal source.

  2. Optical parametric osicllators with improved beam quality

    DOEpatents

    Smith, Arlee V.; Alford, William J.

    2003-11-11

    An optical parametric oscillator (OPO) having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately .rho.L.sub.crystal is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.

  3. The Particle Beam Optics Interactive Computer Laboratory

    SciTech Connect

    Gillespie, G.H.; Hill, B.W.; Brown, N.A.; Babcock, R.C.; Martono, H.; Carey, D.C. |

    1997-02-01

    The Particle Beam Optics Interactive Computer Laboratory (PBO Lab) is an educational software concept to aid students and professionals in learning about charged particle beams and particle beam optical systems. The PBO Lab is being developed as a cross-platform application and includes four key elements. The first is a graphic user interface shell that provides for a highly interactive learning session. The second is a knowledge database containing information on electric and magnetic optics transport elements. The knowledge database provides interactive tutorials on the fundamental physics of charged particle optics and on the technology used in particle optics hardware. The third element is a graphical construction kit that provides tools for students to interactively and visually construct optical beamlines. The final element is a set of charged particle optics computational engines that compute trajectories, transport beam envelopes, fit parameters to optical constraints and carry out similar calculations for the student designed beamlines. The primary computational engine is provided by the third-order TRANSPORT code. Augmenting TRANSPORT is the multiple ray tracing program TURTLE and a first-order matrix program that includes a space charge model and support for calculating single particle trajectories in the presence of the beam space charge. This paper describes progress on the development of the PBO Lab. {copyright} {ital 1997 American Institute of Physics.}

  4. The Particle Beam Optics Interactive Computer Laboratory

    SciTech Connect

    Gillespie, George H.; Hill, Barrey W.; Brown, Nathan A.; Babcock, R. Chris; Martono, Hendy; Carey, David C.

    1997-02-01

    The Particle Beam Optics Interactive Computer Laboratory (PBO Lab) is an educational software concept to aid students and professionals in learning about charged particle beams and particle beam optical systems. The PBO Lab is being developed as a cross-platform application and includes four key elements. The first is a graphic user interface shell that provides for a highly interactive learning session. The second is a knowledge database containing information on electric and magnetic optics transport elements. The knowledge database provides interactive tutorials on the fundamental physics of charged particle optics and on the technology used in particle optics hardware. The third element is a graphical construction kit that provides tools for students to interactively and visually construct optical beamlines. The final element is a set of charged particle optics computational engines that compute trajectories, transport beam envelopes, fit parameters to optical constraints and carry out similar calculations for the student designed beamlines. The primary computational engine is provided by the third-order TRANSPORT code. Augmenting TRANSPORT is the multiple ray tracing program TURTLE and a first-order matrix program that includes a space charge model and support for calculating single particle trajectories in the presence of the beam space charge. This paper describes progress on the development of the PBO Lab.

  5. Optical Beam Control Using Adaptive Optics

    DTIC Science & Technology

    2005-12-01

    30 1. Principles of Operation......................................................................31 VI. USING ZERNIKE POLYNOMIALS TO...help patience in helping me to understand the underlying principles of optics. xiv THIS PAGE INTENTIONALLY...correct this using adaptive optics. Adaptive Optics first got its start in 215 AD with the destruction of the Roman Fleet by Archimedes (Lamberson

  6. Vortex-based line beam optical tweezers

    NASA Astrophysics Data System (ADS)

    Cheng, Shubo; Tao, Shaohua

    2016-10-01

    A vortex-based line beam, which has a straight-line shape of intensity and possesses phase gradient along the line trajectory is developed and applied for optical manipulation in this paper. The intensity and phase distributions of the beam in the imaging plane of the Fourier transform are analytically studied. Simulation results show that the length of the line and phase gradient possessed by a vortex-based line beam are dependent on the topological charge and the azimuthal proportional constant. A superposition of multiple phase-only holograms with elliptical azimuthal phases can be used to generate an array of vortex-based line beams. Optical trapping with the vortex-based line beams has been implemented. Furthermore, the automatic transportation of microparticles along the line trajectory perpendicular to the optical axis is realized with an array of the beams. The generation method for the vortex-based line beam is simple. The beam would have potential applications in fields such as optical trapping, laser machining, and so on.

  7. Optical Mounts for Cryogenic Beam Splitters

    NASA Technical Reports Server (NTRS)

    Rudman, A. A.

    1985-01-01

    Spring-loaded optical mounts maintain flatness and alinement of rigid, framed, or pellicle beam splitters over wide temperature range, despite differences in thermal expansion amoung materials. Mounts permit optical adjustments at ambient temperature even though optical system operated subsequently within few degrees of absolute zero. Mounts useful as holders for integrated-circuit master patterns, survey targets, vibrating membranes, noise- or pressure-sensing membranes, osmosis filters, and fuel-cell elements.

  8. Imaging techniques with refractive beam shaping optics

    NASA Astrophysics Data System (ADS)

    Laskin, Alexander; Laskin, Vadim

    2012-10-01

    Applying of the refractive beam shapers in real research optical setups as well as in industrial installations requires very often manipulation of a final laser spot size. In many cases this task can be easily solved by using various imaging optical layouts presuming creating an image of a beam shaper output aperture. Due to the unique features of the refractive beam shapers of field mapping type, like flat wave front and low divergence of the collimated resulting beam with flattop or another intensity profile, there is a freedom in building of various imaging systems with using ordinary optical components, including off-the-shelf ones. There will be considered optical layouts providing high, up to 1/200×, de-magnifying factors, combining of refractive beam shapers like πShaper with scanning systems, building of relay imaging systems with extended depth of field. These optical layouts are widely used in such laser technologies like drilling holes in PCB, welding, various micromachining techniques with galvo-mirror scanning, interferometry and holography, various SLM-based applications. Examples of real implementations and experimental results will be presented as well.

  9. Optical beam diagnostics on PEP

    SciTech Connect

    Sabersky, A.P.

    1981-02-01

    In designing the PEP optical diagnostics we have been able to build on the experience gained with SPEAR. Most of the problems at SPEAR could be traced to the optical diagnostic system being inside the tunnel. A machine shutdown is required for any maintenance or modification. This implies that in order to make such an instrument successful, a large engineering effort must be mounted to ensure 100% operation at startup. The functions that do not work at startup may never be made to work; this has happened at several machines. Experimental setups are likewise risky and time consuming. A point which has been borne out in both SPEAR and PEP is that the mechanical part of the instrument, the special vacuum chamber, the optical mounts, the alignment and adjustments, require approximately 60% of the effort and cost of the optical diagnostics. It is far better to economize on detectors and electronics than on mechanical and optical essentials.

  10. Maritime Adaptive Optics Beam Control

    DTIC Science & Technology

    2010-09-01

    can employ enclosures, silencers, or mass-spring- damper systems, active noise control employs secondary sources, usually electronic, to produce a...a Fourier filter in the form of an iris or aperture stop is placed in the beam to select either the +1 or -1 diffractive order to propagate through

  11. Diffraction smoothing aperture for an optical beam

    DOEpatents

    Judd, O'Dean P.; Suydam, Bergen R.

    1976-01-01

    The disclosure is directed to an aperture for an optical beam having an irregular periphery or having perturbations imposed upon the periphery to decrease the diffraction effect caused by the beam passing through the aperture. Such apertures are particularly useful with high power solid state laser systems in that they minimize the problem of self-focusing which frequently destroys expensive components in such systems.

  12. Diode amplifier of modulated optical beam power

    SciTech Connect

    D'yachkov, N V; Bogatov, A P; Gushchik, T I; Drakin, A E

    2014-11-30

    Analytical relations are obtained between characteristics of modulated light at the output and input of an optical diode power amplifier operating in the highly saturated gain regime. It is shown that a diode amplifier may act as an amplitude-to-phase modulation converter with a rather large bandwidth (∼10 GHz). The low sensitivity of the output power of the amplifier to the input beam power and its high energy efficiency allow it to be used as a building block of a high-power multielement laser system with coherent summation of a large number of optical beams. (lasers)

  13. Optical vortex beam generator at nanoscale level

    PubMed Central

    Garoli, Denis; Zilio, Pierfrancesco; Gorodetski, Yuri; Tantussi, Francesco; De Angelis, Francesco

    2016-01-01

    Optical beams carrying orbital angular momentum (OAM) can find tremendous applications in several fields. In order to apply these particular beams in photonic integrated devices innovative optical elements have been proposed. Here we are interested in the generation of OAM-carrying beams at the nanoscale level. We design and experimentally demonstrate a plasmonic optical vortex emitter, based on a metal-insulator-metal holey plasmonic vortex lens. Our plasmonic element is shown to convert impinging circularly polarized light to an orbital angular momentum state capable of propagating to the far-field. Moreover, the emerging OAM can be externally adjusted by switching the handedness of the incident light polarization. The device has a radius of few micrometers and the OAM beam is generated from subwavelength aperture. The fabrication of integrated arrays of PVLs and the possible simultaneous emission of multiple optical vortices provide an easy way to the large-scale integration of optical vortex emitters for wide-ranging applications. PMID:27404659

  14. Electro-optic and Acousto-optic Laser Beam Scanners

    NASA Astrophysics Data System (ADS)

    Römer, G. R. B. E.; Bechtold, P.

    Optical solid state deflectors rely on the electro-optical or acousto-optic effect. These Electro-Optical Deflectors (EODs) and Acousto-Optical Deflectors (AODs) do not contain moving parts and therefore exhibit high deflection velocities and are free of drawbacks associated with mechanical scanners. A description of the principles of operation of EODs and AODs is presented. In addition, characteristics, properties and the (dis)advantages of EODs and AODs, when compared to mirror based mechanical deflectors, is discussed. Deflection angles, speed and accuracy are discussed in terms of resolvable spots and related quantities. Also, response time, damage threshold, efficiency and the type and magnitude of beam distortions is addressed. Optical deflectors are characterized by high angular deflection velocities, but small deflection angles. Whereas mechanical mechanical scanners are characterized by relatively small deflection velocities, but large deflection angles. Arranging an optical deflector and a mechanical scanner in series allows to take advantage of the best of both worlds.

  15. Self-trapping of optical beams through thermophoresis.

    PubMed

    Lamhot, Yuval; Barak, Assaf; Peleg, Or; Segev, Mordechai

    2010-10-15

    We demonstrate, theoretically and experimentally, self-trapping of optical beams in nanoparticle suspensions by virtue of thermophoresis. We use light to control the local concentration of nanoparticles, and increase their density at the center of the optical beam, thereby increasing the effective refractive index in the beam vicinity, causing the beam to self-trap.

  16. Triple beam optical trap for microsyringe construction

    NASA Astrophysics Data System (ADS)

    Ramsay, William T.; Bechu, Muriel; Bolanos Quinones, Vladimir A.; Mei, Yongfeng; Schmidt, Oliver G.; Paterson, Lynn

    2011-10-01

    A limited range of instruments are available which allow the controlled injection of sub-picolitre volumes; microfluidic devices and commercially produced mechanical microinjection systems accounting for the majority. We present an optically controlled microsyringe capable of dispensing femtolitres of liquid. Triple beam optical tweezers are used to manipulate hollow glass microneedles and also polymer microspheres which were used as 'handles' to assist the manipulation of microneedles and 'plungers' to dispense liquid from the microneedle. Standard optical tweezers were used with the addition of a Ronchi ruling (250 lines per inch) mounted in the image relay telescope. The diffraction pattern generated by the Ronchi ruling produced three optical traps in the sample chamber. Trap spacing was controlled by translating the ruling along the axis of beam propagation within the image relay telescope. Utilizing the three-beam trap, it was possible to manipulate pulled, borosilicate capillaries (5-150μm in length, 1-10μm in diameter) both perpendicular and parallel to the axis of the capillary. Rolled SiO/SiO2 microtubes (4μm diameter, 50μm long) were also manipulated, however in this case polymer microspheres were used as 'handles'. In both cases the microneedles did not align vertically along the propagation axis; an advantage over using a single beam optical trap. Tweezing a microsphere within a microneedle dispenses femtolitres of liquid from the needle. The force exerted on microneedles is calculated to be in the order of picoNewtons so may have applications where femtolitre volumes must be controllably delivered beyond a barrier, such as single cell microinjection.

  17. Pencil beam all-optical ultrasound imaging

    PubMed Central

    Alles, Erwin J.; Noimark, Sacha; Zhang, Edward; Beard, Paul C.; Desjardins, Adrien E.

    2016-01-01

    A miniature, directional fibre-optic acoustic source is presented that employs geometrical focussing to generate a nearly-collimated acoustic pencil beam. When paired with a fibre-optic acoustic detector, an all-optical ultrasound probe with an outer diameter of 2.5 mm is obtained that acquires a pulse-echo image line at each probe position without the need for image reconstruction. B-mode images can be acquired by translating the probe and concatenating the image lines, and artefacts resulting from probe positioning uncertainty are shown to be significantly lower than those observed for conventional synthetic aperture scanning of a non-directional acoustic source. The high image quality obtained for excised vascular tissue suggests that the all-optical ultrasound probe is ideally suited for in vivo, interventional applications. PMID:27699130

  18. Ultrafast Airy beam optical parametric oscillator.

    PubMed

    Apurv Chaitanya, N; Kumar, S Chaitanya; Aadhi, A; Samanta, G K; Ebrahim-Zadeh, M

    2016-08-01

    We report on the first realization of an ultrafast Airy beam optical parametric oscillator (OPO). By introducing intracavity cubic phase modulation to the resonant Gaussian signal in a synchronously-pumped singly-resonant OPO cavity and its subsequent Fourier transformation, we have generated 2-dimensional Airy beam in the output signal across a 250 nm tuning range in the near-infrared. The generated Airy beam can be tuned continuously from 1477 to 1727 nm, providing an average power of as much as 306 mW at 1632 nm in pulses of ~23 ps duration with a spectral bandwidth of 1.7 nm.

  19. Transformation-optical Fan-beam Synthesis

    PubMed Central

    Yang, Rui; Kong, Xianghui; Wang, Hui; Su, He; Lei, Zhenya; Wang, Jing; Zhang, Aofang; Chen, Lei

    2016-01-01

    Gradient-index dielectric lenses are generated based on the coordinate transformation by compressing the homogeneous air spaces quasi-conformally towards and outwards the primary source. The three-dimensional modeling is then performed through revolving the prescribed transformational media 180 degrees around the focal point to reach the architecture of barrel-vaults. It is found that all these two- and three-dimensional transformation-optical designs are capable of producing fan-beams efficiently over a broad frequency range with their main lobes possessing the narrow beamwidth in one dimension and the wide beamwidth in the other, while having the great ability of the wide angular scanning. Finally, we propose to construct such four types of fan-beam lenses through multiple-layered dielectrics with non-uniformed perforations and experimentally demonstrate their excellent performances in the fan-beam synthesis. PMID:26847048

  20. Ultrafast Airy beam optical parametric oscillator

    PubMed Central

    Apurv Chaitanya, N.; Kumar, S. Chaitanya; Aadhi, A.; Samanta, G. K.; Ebrahim-Zadeh, M.

    2016-01-01

    We report on the first realization of an ultrafast Airy beam optical parametric oscillator (OPO). By introducing intracavity cubic phase modulation to the resonant Gaussian signal in a synchronously-pumped singly-resonant OPO cavity and its subsequent Fourier transformation, we have generated 2-dimensional Airy beam in the output signal across a 250 nm tuning range in the near-infrared. The generated Airy beam can be tuned continuously from 1477 to 1727 nm, providing an average power of as much as 306 mW at 1632 nm in pulses of ~23 ps duration with a spectral bandwidth of 1.7 nm. PMID:27476910

  1. Transformation-optical Fan-beam Synthesis

    NASA Astrophysics Data System (ADS)

    Yang, Rui; Kong, Xianghui; Wang, Hui; Su, He; Lei, Zhenya; Wang, Jing; Zhang, Aofang; Chen, Lei

    2016-02-01

    Gradient-index dielectric lenses are generated based on the coordinate transformation by compressing the homogeneous air spaces quasi-conformally towards and outwards the primary source. The three-dimensional modeling is then performed through revolving the prescribed transformational media 180 degrees around the focal point to reach the architecture of barrel-vaults. It is found that all these two- and three-dimensional transformation-optical designs are capable of producing fan-beams efficiently over a broad frequency range with their main lobes possessing the narrow beamwidth in one dimension and the wide beamwidth in the other, while having the great ability of the wide angular scanning. Finally, we propose to construct such four types of fan-beam lenses through multiple-layered dielectrics with non-uniformed perforations and experimentally demonstrate their excellent performances in the fan-beam synthesis.

  2. Ultrafast Airy beam optical parametric oscillator

    NASA Astrophysics Data System (ADS)

    Apurv Chaitanya, N.; Kumar, S. Chaitanya; Aadhi, A.; Samanta, G. K.; Ebrahim-Zadeh, M.

    2016-08-01

    We report on the first realization of an ultrafast Airy beam optical parametric oscillator (OPO). By introducing intracavity cubic phase modulation to the resonant Gaussian signal in a synchronously-pumped singly-resonant OPO cavity and its subsequent Fourier transformation, we have generated 2-dimensional Airy beam in the output signal across a 250 nm tuning range in the near-infrared. The generated Airy beam can be tuned continuously from 1477 to 1727 nm, providing an average power of as much as 306 mW at 1632 nm in pulses of ~23 ps duration with a spectral bandwidth of 1.7 nm.

  3. Nonparaxial Near-Nondiffracting Accelerating Optical Beams

    NASA Astrophysics Data System (ADS)

    Lai, Ru-Yu; Zhou, Ting

    2017-02-01

    We show that new families of accelerating and almost nondiffracting beams (solutions) for Maxwell's equations can be constructed. These are complex geometrical optics (CGO) solutions to Maxwell's equations with nonlinear limiting Carleman weights. They have the form of wave packets that propagate along circular trajectories while almost preserving a transverse intensity profile. We also show similar waves constructed using the approach combining CGO solutions and the Kelvin transform.

  4. SLC polarized beam source electron optics design

    SciTech Connect

    Eppley, K.R.; Lavine, T.L.; Early, R.A.; Herrmannsfeldt, W.B.; Miller, R.H.; Schultz, D.C.; Spencer, C.M.; Yeremian, A.D.

    1991-05-01

    This paper describes the design of the beam-line from the polarized electron gun to the linac injector in the Stanford Linear Collider (SLC). The polarized electron source is a GaAs photocathode, requiring 10{sup {minus}11}-Torr-range pressure for adequate quantum efficiency and longevity. The photocathode is illuminated by 3-nsec-long laser pulses. The quality of the optics for the 160-kV beam is crucial since electron-stimulated gas desorption from beam loss in excess of 0.1% of the 20-nC pulses may poison the photocathode. Our design for the transport line consists of a differential pumping region isolated by a pair of valves. Focusing is provided by a pair of Helmholtz coils and by several iron-encased solenoidal lenses. Our optics design is based on beam transport simulations using 2{1/2}-D particle-in-cell codes to model the gun and to solve the fully-relativistic time-dependent equations of motion in three dimensions for electrons in the presence of azimuthally symmetric electromagnetic fields. 6 refs., 6 figs.

  5. Ion beam figuring of small optical components

    NASA Astrophysics Data System (ADS)

    Drueding, Thomas W.; Fawcett, Steven C.; Wilson, Scott R.; Bifano, Thomas G.

    1995-12-01

    Ion beam figuring provides a highly deterministic method for the final precision figuring of optical components with advantages over conventional methods. The process involves bombarding a component with a stable beam of accelerated particles that selectively removes material from the surface. Figure corrections are achieved by rastering the fixed-current beam across the workplace at appropriate, time-varying velocities. Unlike conventional methods, ion figuring is a noncontact technique and thus avoids such problems as edge rolloff effects, tool wear, and force loading of the workpiece. This work is directed toward the development of the precision ion machining system at NASA's Marshall Space Flight Center. This system is designed for processing small (approximately equals 10-cm diam) optical components. Initial experiments were successful in figuring 8-cm-diam fused silica and chemical-vapor-deposited SiC samples. The experiments, procedures, and results of figuring the sample workpieces to shallow spherical, parabolic (concave and convex), and non-axially-symmetric shapes are discussed. Several difficulties and limitations encountered with the current system are discussed. The use of a 1-cm aperture for making finer corrections on optical components is also reported.

  6. Interferometric optical fiber microcantilever beam biosensor

    NASA Astrophysics Data System (ADS)

    Wavering, Thomas A.; Meller, Scott A.; Evans, Mishell K.; Pennington, Charles; Jones, Mark E.; VanTassell, Roger; Murphy, Kent A.; Velander, William H.; Valdes, E.

    2000-12-01

    With the proliferation of biological weapons, the outbreak of food poisoning occurrences, and the spread of antibiotic resistant strains of pathogenic bacteria, the demand has arisen for portable systems capable of rapid, specific, and quantitative target detection. The ability to detect minute quantities of targets will provide the means to quickly assess a health hazardous situation so that the appropriate response can be orchestrated. Conventional test results generally require hours or even several days to be reported, and there is no change for real-time feedback. An interferometric optical fiber microcantilever beam biosensor has successfully demonstrated real time detection of target molecules. The microcantilever biosensor effectively combines advanced technology from silicon micromachining, optical fiber sensor, and biochemistry to create a novel detection device. This approach utilizes affinity coatings on micromachiend cantilever beams to attract target molecules. The presence of the target molecule causes bending in the cantilever beam, which is monitored using an optical displacement system. Dose-response trials have shown measured responses at nanogram/ml concentrations of target molecules. Sensitivity is expected to extend from the nanogram to the picogram range of total captured mass as the microcantilever sensors are optimized.

  7. Optical vortex beam based optical fan for high-precision optical measurements and optical switching.

    PubMed

    Zhou, Zhi-Yuan; Li, Yan; Ding, Dong-Sheng; Zhang, Wei; Shi, Shuai; Shi, Bao-Sen

    2014-09-01

    The polarization and orbital angular momentum properties of light are of great importance in optical science and technology in the fields of high-precision optical measurements and high-capacity and high-speed optical communications. Here we show a method for the construction of a simple and robust scheme to rotate a light beam such as a fan, which is based on a combination of these two properties and using the thermal-dispersion and electro-optical effect of birefringent crystals. Using a computer-based digital image-processing technique, we determine the temperature and thermal-dispersion difference of the crystal with high resolution. We also use the rotation phenomenon to realize thermo-optic and electro-optic switches. The basic operating principles for measurement and switching processes are presented in detail. The methods developed here will have wide practical applicability in various fields, including remote sensing, materials science, and optical communication networks.

  8. Beam shaping for laser initiated optical primers

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd E.

    2008-08-01

    Remington was one of the first firearm manufacturing companies to file a patent for laser initiated firearms, in 1969. Nearly 40 years later, the development of laser initiated firearms has not become a mainstream technology in the civilian market. Requiring a battery is definitely a short coming, so it is easy to see how such a concept would be problematic. Having a firearm operate reliably and the delivery of laser energy in an efficient manner to ignite the shock-sensitive explosive primer mixtures is a tall task indeed. There has been considerable research on optical element based methods of transferring or compressing laser energy to ignite primer charges, including windows, laser chip primers and various lens shaped windows to focus the laser energy. The focusing of laser light needs to achieve igniting temperatures upwards of >400°C. Many of the patent filings covering this type of technology discuss simple approaches where a single point of light might be sufficient to perform this task. Alternatively a multi-point method might provide better performance, especially for mission critical applications, such as precision military firearms. This paper covers initial design and performance test of the laser beam shaping optics to create simultaneous multiple point ignition locations and a circumferential intense ring for igniting primer charge compounds. A simple initial test of the ring beam shaping technique was evaluated on a standard large caliber primer to determine its effectiveness on igniting the primer material. Several tests were conducted to gauge the feasibility of laser beam shaping, including optic fabrication and mounting on a cartridge, optic durability and functional ignition performance. Initial data will be presented, including testing of optically elements and empirical primer ignition / burn analysis.

  9. An electron optical theory of beam blanking

    NASA Astrophysics Data System (ADS)

    Gesley, M.

    1993-11-01

    Trajectory equations are derived in closed form for electrons in time-dependent electric fields produced by beam blankers. Simple parallel plate and double-deflection blankers with transmission delay lines are evaluated. Lens imaging of the apparent beam motion is analyzed by developing the virtual electron trajectories obtained from linear extrapolation back into the blanker region. Lens excitation effects and conjugate blanking optics can then be described. The blanker voltage is represented by a damped exponential cosine term, which satisfies a typical circuit equation for the driver-amplifier. The form of the trajectory equation is written as a 3×3 matrix, which comprises a set of conditional solutions that are determined by blanker geometry. The optimum delay line length of any double-deflection blanker can then be determined. The blanker-induced beam jitter is shown to be significantly reduced by using this configuration. The effect of the blanker beam stop on the motion at the target plane is given by combining results on the real and apparent beam trajectories.

  10. Optical remote diagnostics of atmospheric propagating beams of ionizing radiation

    DOEpatents

    Karl JR., Robert R.

    1990-03-06

    Data is obtained for use in diagnosing the characteristics of a beam of ionizing radiation, such as charged particle beams, neutral particle beams, and gamma ray beams. In one embodiment the beam is emitted through the atmosphere and produces nitrogen fluorescence during passage through air. The nitrogen fluorescence is detected along the beam path to provide an intensity from which various beam characteristics can be calculated from known tabulations. Optical detecting equipment is preferably located orthogonal to the beam path at a distance effective to include the entire beam path in the equipment field of view.

  11. Optical remote diagnostics of atmospheric propagating beams of ionizing radiation

    DOEpatents

    Karl, Jr., Robert R.

    1990-01-01

    Data is obtained for use in diagnosing the characteristics of a beam of ionizing radiation, such as charged particle beams, neutral particle beams, and gamma ray beams. In one embodiment the beam is emitted through the atmosphere and produces nitrogen fluorescence during passage through air. The nitrogen fluorescence is detected along the beam path to provide an intensity from which various beam characteristics can be calculated from known tabulations. Optical detecting equipment is preferably located orthogonal to the beam path at a distance effective to include the entire beam path in the equipment field of view.

  12. Indexing system for optical beam steering

    NASA Technical Reports Server (NTRS)

    Sullivan, Mark T.; Cannon, David M.; Debra, Daniel B.; Young, Jeffrey A.; Mansfield, Joseph A.; Carmichael, Roger E.; Lissol, Peter S.; Pryor, G. M.; Miklosy, Les G.; Lee, Jeffrey H.

    1990-01-01

    This paper describes the design and testing of an indexing system for optical-beam steering. The cryogenic beam-steering mechanism is a 360-degree rotation device capable of discrete, high-precision alignment positions. It uses low-precision components for its rough alignment and kinematic design to meet its stringent repeatability and stability requirements (of about 5 arcsec). The principal advantages of this design include a decoupling of the low-precision, large angular motion from the high-precision alignment, and a power-off alignment position that potentially extends the life or hold time of cryogenic systems. An alternate design, which takes advantage of these attributes while reducing overall motion, is also presented. Preliminary test results show the kinematic mount capable of sub-arc second repeatability.

  13. Optical tailoring of xFEL beams

    SciTech Connect

    West, Gavin; Coffee, R.

    2015-08-20

    There is an inherent exibility unique to free electron lasers (FELs) that lends well to experimental approaches normally too difficult for other light sources to accomplish. This includes the ability to optically shape the electron bunch prior to final its acceleration for the final FEL process. Optical pulse shaping of the electron bunch can enable both femtosecond and attosecond level FEL pulse control. Pulse shaping is currently implemented, not optically but mechanically, in LCLS-I with an adjustable foil slit that physically spoils the momentum phase of the electron bunch. This selectively suppresses the downstream FEL process ofspoiled electrons. Such a mechanical spoiling method fails for both the soft x-ray regime as well as the high repetition rates that are planned in LCLS-II. Our proposed optical spoiling method circumvents this limitation by making use of the existing ultrafast laser beam that is typically used for adjusting the energy spread for the initial electron bunch. Using Fourier domain shaping we can nearly arbitrarily shape the laser pulses to affect the electron bunch. This can selectively spoil electrons within each bunch. Here we demonstrate the viability of this approach with a programmable acousto-optic dispersive filter. This method is not only well suited for LCLS-II but also has several advantages over mechanical spoiling, including lack of radiation concerns, experiment specific FEL pulse shapes, and real-time adjustment for applications that require high duty-cycle variation such as lock-in amplification of small signals.

  14. Canonical formalism for coupled beam optics

    SciTech Connect

    Kheifets, S.A.

    1989-09-01

    Beam optics of a lattice with an inter-plane coupling is treated using canonical Hamiltonian formalism. The method developed is equally applicable both to a circular (periodic) machine and to an open transport line. A solution of the equation of a particle motion (and correspondingly transfer matrix between two arbitrary points of the lattice) are described in terms of two amplitude functions (and their derivatives and corresponding phases of oscillations) and four coupling functions, defined by a solution of the system of the first-order nonlinear differential equations derived in the paper. Thus total number of independent parameters is equal to ten. 8 refs.

  15. Electro-Optic Beam Steering Using Domain Engineered Lithium Tantalate

    DTIC Science & Technology

    2005-03-01

    becomes (ne + ∆ne) d = ned + ∆ned. (6.1) where ∆ne is the electro- optically induced change in the index. Combining with Equation 2.32 ∆ned = ± 1 2 ...utilizing numerous electro-mechanical, acousto - optic and electro- optic steering mechanisms [3, 7, 14,15,17,18]. As a special motivation for this...angle electro- optic beam scanner,(b) Gradient type electro- optic beam scanner, (c)Prism type electro- optic beam scanner. 2 Additional attempts to

  16. Optical beam forming techniques for phased array antennas

    NASA Astrophysics Data System (ADS)

    Wu, Te-Kao; Chandler, C.

    Conventional phased array antennas using waveguide or coax for signal distribution are impractical for large scale implementation on satellites or spacecraft because they exhibit prohibitively large system size, heavy weight, high attenuation loss, limited bandwidth, sensitivity to electromagnetic interference (EMI) temperature drifts and phase instability. However, optical beam forming systems are smaller, lighter, and more flexible. Three optical beam forming techniques are identified as applicable to large spaceborne phased array antennas. They are (1) the optical fiber replacement of conventional RF phased array distribution and control components, (2) spatial beam forming, and (3) optical beam splitting with integrated quasi-optical components. The optical fiber replacement and the spatial beam forming approaches were pursued by many organizations. Two new optical beam forming architectures are presented. Both architectures involve monolithic integration of the antenna radiating elements with quasi-optical grid detector arrays. The advantages of the grid detector array in the optical process are the higher power handling capability and the dynamic range. One architecture involves a modified version of the original spatial beam forming approach. The basic difference is the spatial light modulator (SLM) device for controlling the aperture field distribution. The original liquid crystal light valve SLM is replaced by an optical shuffling SLM, which was demonstrated for the 'smart pixel' technology. The advantages are the capability of generating the agile beams of a phased array antenna and to provide simultaneous transmit and receive functions. The second architecture considered is the optical beam splitting approach. This architecture involves an alternative amplitude control for each antenna element with an optical beam power divider comprised of mirrors and beam splitters. It also implements the quasi-optical grid phase shifter for phase control and grid

  17. Optical beam forming techniques for phased array antennas

    NASA Technical Reports Server (NTRS)

    Wu, Te-Kao; Chandler, C.

    1993-01-01

    Conventional phased array antennas using waveguide or coax for signal distribution are impractical for large scale implementation on satellites or spacecraft because they exhibit prohibitively large system size, heavy weight, high attenuation loss, limited bandwidth, sensitivity to electromagnetic interference (EMI) temperature drifts and phase instability. However, optical beam forming systems are smaller, lighter, and more flexible. Three optical beam forming techniques are identified as applicable to large spaceborne phased array antennas. They are (1) the optical fiber replacement of conventional RF phased array distribution and control components, (2) spatial beam forming, and (3) optical beam splitting with integrated quasi-optical components. The optical fiber replacement and the spatial beam forming approaches were pursued by many organizations. Two new optical beam forming architectures are presented. Both architectures involve monolithic integration of the antenna radiating elements with quasi-optical grid detector arrays. The advantages of the grid detector array in the optical process are the higher power handling capability and the dynamic range. One architecture involves a modified version of the original spatial beam forming approach. The basic difference is the spatial light modulator (SLM) device for controlling the aperture field distribution. The original liquid crystal light valve SLM is replaced by an optical shuffling SLM, which was demonstrated for the 'smart pixel' technology. The advantages are the capability of generating the agile beams of a phased array antenna and to provide simultaneous transmit and receive functions. The second architecture considered is the optical beam splitting approach. This architecture involves an alternative amplitude control for each antenna element with an optical beam power divider comprised of mirrors and beam splitters. It also implements the quasi-optical grid phase shifter for phase control and grid

  18. 2D optical beam splitter using diffractive optical elements (DOE)

    NASA Astrophysics Data System (ADS)

    Wen, Fung J.; Chung, Po S.

    2006-09-01

    A novel approach for optical beam distribution into a 2-dimensional (2-D) packaged fiber arrays using 2-D Dammann gratings is investigated. This paper focuses on the design and fabrication of the diffractive optical element (DOE) and investigates the coupling efficiencies of the beamlets into a packaged V-grooved 2x2 fibre array. We report for the first time experimental results of a 2-D optical signal distribution into a packaged 2x2 fibre array using Dammann grating. This grating may be applicable to the FTTH network as it can support sufficient channels with good output uniformity together with low polarization dependent loss (PDL) and acceptable insertion loss. Using an appropriate optimization algorithm (the steepest descent algorithm in this case), the optimum profile for the gratings can be calculated. The gratings are then fabricated on ITO glass using electron-beam lithography. The overall performance of the design shows an output uniformity of around 0.14 dB and an insertion loss of about 12.63 dB, including the DOE, focusing lens and the packaged fiber array.

  19. Transverse Beam Shape Measurements of Intense Proton Beams Using Optical Transition Radiation

    NASA Astrophysics Data System (ADS)

    Scarpine, Victor E.

    A number of particle physics experiments are being proposed as part of the Department of Energy HEP Intensity Frontier. Many of these experiments will utilize megawatt level proton beams onto targets to form secondary beams of muons, kaons and neutrinos. These experiments require transverse size measurements of the incident proton beam onto target for each beam spill. Because of the high power levels, most beam intercepting profiling techniques will not work at full beam intensity. The possibility of utilizing optical transition radiation (OTR) for high intensity proton beam profiling is discussed. In addition, previous measurements of OTR beam profiles from the NuMI beamline are presented.

  20. Transverse beam shape measurements of intense proton beams using optical transition radiation

    SciTech Connect

    Scarpine, Victor E.; /Fermilab

    2012-03-01

    A number of particle physics experiments are being proposed as part of the Department of Energy HEP Intensity Frontier. Many of these experiments will utilize megawatt level proton beams onto targets to form secondary beams of muons, kaons and neutrinos. These experiments require transverse size measurements of the incident proton beam onto target for each beam spill. Because of the high power levels, most beam intercepting profiling techniques will not work at full beam intensity. The possibility of utilizing optical transition radiation (OTR) for high intensity proton beam profiling is discussed. In addition, previous measurements of OTR beam profiles from the NuMI beamline are presented.

  1. Initial alignment method for free space optics laser beam

    NASA Astrophysics Data System (ADS)

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

    2016-08-01

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

  2. Optics of ion beams for the neutral beam injection system on HL-2A Tokamak

    SciTech Connect

    Zou, G. Q.; Lei, G. J.; Cao, J. Y.; Duan, X. R.

    2012-07-15

    The ion beam optics for the neutral beam injection system on HL-2A Tokomak is studied by two- dimensional numerical simulation program firstly, where the emitting surface is taken at 100 Debye lengths from the plasma electrode. The mathematical formulation, computation techniques are described. Typical ion orbits, equipotential contours, and emittance diagram are shown. For a fixed geometry electrode, the effect of plasma density, plasma potential and plasma electron temperature on ion beam optics is examined, and the calculation reliability is confirmed by experimental results. In order to improve ion beam optics, the application of a small pre-acceleration voltage ({approx}100 V) between the plasma electrode and the arc discharge anode is reasonable, and a lower plasma electron temperature is desired. The results allow optimization of the ion beam optics in the neutral beam injection system on HL-2A Tokomak and provide guidelines for designing future neutral beam injection system on HL-2M Tokomak.

  3. Modal Frequency Detection in Composite Beams Using Fiber Optic Sensors

    DTIC Science & Technology

    2011-07-28

    optic sensors showed more sensitivity and better signal-to-noise ratios. The analytical classical beam theory and a finite element model validated the...61 C. INPUT AND OUTPUT FOR THE FINITE ELEMENT MODEL ..... 88 B IB LIO G RA PH Y...beam compared to MATLAB generated frequencies of classical beam theory and frequencies calculated using a finite element model (FEM

  4. Wave optics simulation approach for partial spatially coherent beams.

    PubMed

    Xiao, Xifeng; Voelz, David

    2006-08-07

    A numerical wave optics approach for simulating a partial spatially coherent beam is presented. The approach involves the application of a sequence of random phase screens to an initial beam field and the summation of the intensity results after propagation. The relationship between the screen parameters and the spatial coherence function for the beam is developed and the approach is verified by comparing results with analytic formulations for a Gaussian Schell-model beam. The approach can be used for modeling applications such as free space optical laser links that utilize partially coherent beams.

  5. Optical rogue waves generated on Gaussian background beam.

    PubMed

    Liu, Chong; Yang, Zhan-Ying; Zhao, Li-Chen; Xin, Guo-Guo; Yang, Wen-Li

    2014-02-15

    We study optical rogue waves (RWs) in a nonlinear graded-index waveguide with variable coefficients. An exact RW solution on Gaussian background beam is presented, in contrast to the previous studies about RWs, on plane wave background. It is shown that the characteristics of RWs are maintained on Gaussian background beam and that the beam's width is even a bit smaller than the RWs scale. These results may raise the possibility of related experiments and potential applications in nonlinear optics.

  6. Designing a fiber-optic beam delivery system

    SciTech Connect

    Hunter, B.V. |; Leong, K.H.; Sanders, P.G.

    1997-03-01

    One of the advantages offered by visible and NIR lasers over CO and CO{sub 2} lasers is that they can be delivered through optical fibers. Fiber-optic beam delivery is ideal when the beam must be delivered along a complex path or processing requires complicated manipulation of the beam delivery optics. Harnessing the power of a high-power laser requires that knowledgeable and prudent choices be made when selecting the laser and its beam delivery system. The purpose of this paper is to discuss a variety of issues important when designing a beam delivery system-data obtained with high power Nd:YAG lasers will be used as illustrative examples. (1) Multimode optical fibers are used for high-power applications. The fiber imposes, to varying degrees, a structure on the beam that is different from the laser output. Fibers degrade the beam quality, although the degree of degradation is dependent on the fiber length, diameter and type. Smaller fibers tend to produce less degradation to beam quality, but the minimum usable fiber size is limited by the quality of the laser beam, focusing optic and the numerical aperture of the fiber. (2) The performance of the beam delivery system is ultimately determined by the quality of the optics. Therefore, well-corrected optics are required to realize the best possible performance. Tests with both homogeneous and GRADIUM{trademark} lenses provide insights into evaluating the benefits offered by improvements in the output optics from gradient-index, aspheric and multi-element lens systems. Additionally, these tests illustrate the origins of variable focused spot size and position with increasing laser power. (3) The physical hardware used in the beam delivery system will have several characteristics which enhance its functionality and ease of use, in addition to facilitating the use of advanced diagnostics and monitoring techniques.

  7. Highly integrated optical phased arrays: photonic integrated circuits for optical beam shaping and beam steering

    NASA Astrophysics Data System (ADS)

    Heck, Martijn J. R.

    2016-06-01

    Technologies for efficient generation and fast scanning of narrow free-space laser beams find major applications in three-dimensional (3D) imaging and mapping, like Lidar for remote sensing and navigation, and secure free-space optical communications. The ultimate goal for such a system is to reduce its size, weight, and power consumption, so that it can be mounted on, e.g. drones and autonomous cars. Moreover, beam scanning should ideally be done at video frame rates, something that is beyond the capabilities of current opto-mechanical systems. Photonic integrated circuit (PIC) technology holds the promise of achieving low-cost, compact, robust and energy-efficient complex optical systems. PICs integrate, for example, lasers, modulators, detectors, and filters on a single piece of semiconductor, typically silicon or indium phosphide, much like electronic integrated circuits. This technology is maturing fast, driven by high-bandwidth communications applications, and mature fabrication facilities. State-of-the-art commercial PICs integrate hundreds of elements, and the integration of thousands of elements has been shown in the laboratory. Over the last few years, there has been a considerable research effort to integrate beam steering systems on a PIC, and various beam steering demonstrators based on optical phased arrays have been realized. Arrays of up to thousands of coherent emitters, including their phase and amplitude control, have been integrated, and various applications have been explored. In this review paper, I will present an overview of the state of the art of this technology and its opportunities, illustrated by recent breakthroughs.

  8. Highly integrated optical phased arrays: photonic integrated circuits for optical beam shaping and beam steering

    NASA Astrophysics Data System (ADS)

    Heck, Martijn J. R.

    2017-01-01

    Technologies for efficient generation and fast scanning of narrow free-space laser beams find major applications in three-dimensional (3D) imaging and mapping, like Lidar for remote sensing and navigation, and secure free-space optical communications. The ultimate goal for such a system is to reduce its size, weight, and power consumption, so that it can be mounted on, e.g. drones and autonomous cars. Moreover, beam scanning should ideally be done at video frame rates, something that is beyond the capabilities of current opto-mechanical systems. Photonic integrated circuit (PIC) technology holds the promise of achieving low-cost, compact, robust and energy-efficient complex optical systems. PICs integrate, for example, lasers, modulators, detectors, and filters on a single piece of semiconductor, typically silicon or indium phosphide, much like electronic integrated circuits. This technology is maturing fast, driven by high-bandwidth communications applications, and mature fabrication facilities. State-of-the-art commercial PICs integrate hundreds of elements, and the integration of thousands of elements has been shown in the laboratory. Over the last few years, there has been a considerable research effort to integrate beam steering systems on a PIC, and various beam steering demonstrators based on optical phased arrays have been realized. Arrays of up to thousands of coherent emitters, including their phase and amplitude control, have been integrated, and various applications have been explored. In this review paper, I will present an overview of the state of the art of this technology and its opportunities, illustrated by recent breakthroughs.

  9. Optical synchrotron radiation beam imaging with a digital mask

    SciTech Connect

    Zhang, Hao; Fiorito, Ralph; Corbett, Jeff; Shkvarunets, Anatoly; Tian, Kai; Fisher, Alan; Douglas, D.; Wilson, F.; Zhang, S.; Mok, W.; Mitsuhashi, T.

    2016-01-01

    The 3GeV SPEAR3 synchrotron light source operates in top-up injection mode with up to 500mA circulating in the storage ring (equivalently 392nC). Each injection pulse contains only 40-80 pC producing a contrast ratio between total stored charge and injected charge of about 6500:1. In order to study transient injected beam dynamics during User operations, it is desirable to optically image the injected pulse in the presence of the bright stored beam. In the present work this is done by re-imaging visible synchrotron radiation onto a digital micro-mirror-array device (DMD), which is then used as an optical mask to block out light from the bright central core of the stored beam. The physical masking, together with an asynchronously-gated, ICCD imaging camera makes it is possible to observe the weak injected beam component on a turn-by-turn basis. The DMD optical masking system works similar to a classical solar coronagraph but has some distinct practical advantages: i.e. rapid adaption to changes in the shape of the stored beam, high extinction ratio for unwanted light and minimum scattering from the primary beam into the secondary optics. In this paper we describe the DMD masking method, features of the high dynamic range point spread function for the SPEAR3 optical beam line and measurements of the injected beam in the presence of the stored beam.

  10. Polymeric waveguide prism-based electro-optic beam deflector

    NASA Astrophysics Data System (ADS)

    Sun, Lin; Kim, Jin-ha; Jang, Chiou-Hung; An, Dechang; Lu, Xuejun; Zhou, Qingjun; Taboada, John M.; Chen, Ray T.; Maki, Jeffery J.; Tang, Suning; Zhang, Hua; Steier, William H.; Zhang, Cheng H.; Dalton, Larry R.

    2001-07-01

    Beam steering devices without moving parts are highly desirable for their potential application in emerging optical technologies such as holographic optical storage systems, all optical networks, and optical switches. We demonstrate a thin-film waveguide beam deflector device that consists of an electro-optic prism array within a polymer waveguide. An electrode structure defines the prism array within the planar waveguide. The deflection efficiency of 28 mrad/kV and the maximum deflection angle of +/- 8.4 mrad at +/- 300 V are obtained for this demonstration device. Further optimization of electrode-field poling and processing is likely to improve these results by at least an order of magnitude.

  11. Optical Manipulation with Plasmonic Beam Shaping Antenna Structures

    DOE PAGES

    Jun, Young Chul; Brener, Igal

    2012-01-01

    Near-field optical trapping of objects using plasmonic antenna structures has recently attracted great attention. However, metal nanostructures also provide a compact platform for general wavefront engineering of intermediate and far-field beams. Here, we analyze optical forces generated by plasmonic beam shaping antenna structures and show that they can be used for general optical manipulation such as guiding of a dielectric particle along a linear or curved trajectory. This removes the need for bulky diffractive optical components and facilitates the integration of optical force manipulation into a highly functional, compact system.

  12. Applications of electron lenses: scraping of high-power beams, beam-beam compensation, and nonlinear optics

    SciTech Connect

    Stancari, Giulio

    2014-09-11

    Electron lenses are pulsed, magnetically confined electron beams whose current-density profile is shaped to obtain the desired effect on the circulating beam. Electron lenses were used in the Fermilab Tevatron collider for bunch-by-bunch compensation of long-range beam-beam tune shifts, for removal of uncaptured particles in the abort gap, for preliminary experiments on head-on beam-beam compensation, and for the demonstration of halo scraping with hollow electron beams. Electron lenses for beam-beam compensation are being commissioned in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). Hollow electron beam collimation and halo control were studied as an option to complement the collimation system for the upgrades of the Large Hadron Collider (LHC) at CERN; a conceptual design was recently completed. Because of their electric charge and the absence of materials close to the proton beam, electron lenses may also provide an alternative to wires for long-range beam-beam compensation in LHC luminosity upgrade scenarios with small crossing angles. At Fermilab, we are planning to install an electron lens in the Integrable Optics Test Accelerator (IOTA, a 40-m ring for 150-MeV electrons) as one of the proof-of-principle implementations of nonlinear integrable optics to achieve large tune spreads and more stable beams without loss of dynamic aperture.

  13. Exotic Optical Beam Classes for Free-Space Communication

    DTIC Science & Technology

    2016-03-24

    surprising connection between vortex evolution and infinite mathematics was uncovered. 15. SUBJECT TERMS atmospheric propagation, optical vortices...different types of optical singularities were discovered and analyzed, and a surprising connection between vortex evolution and infinite mathematics was...fields. DISTRIBUTION A: Distribution approved for public release. 6. Transfinite mathematics in optical vortex beams The investigation of other

  14. Polymorphic beams and Nature inspired circuits for optical current

    PubMed Central

    Rodrigo, José A.; Alieva, Tatiana

    2016-01-01

    Laser radiation pressure is a basis of numerous applications in science and technology such as atom cooling, particle manipulation, material processing, etc. This light force for the case of scalar beams is proportional to the intensity-weighted wavevector known as optical current. The ability to design the optical current according to the considered application brings new promising perspectives to exploit the radiation pressure. However, this is a challenging problem because it often requires confinement of the optical current within tight light curves (circuits) and adapting its local value for a particular task. Here, we present a formalism to handle this problem including its experimental demonstration. It consists of a Nature-inspired circuit shaping with independent control of the optical current provided by a new kind of beam referred to as polymorphic beam. This finding is highly relevant to diverse optical technologies and can be easily extended to electron and x-ray coherent beams. PMID:27734940

  15. Polymorphic beams and Nature inspired circuits for optical current

    NASA Astrophysics Data System (ADS)

    Rodrigo, José A.; Alieva, Tatiana

    2016-10-01

    Laser radiation pressure is a basis of numerous applications in science and technology such as atom cooling, particle manipulation, material processing, etc. This light force for the case of scalar beams is proportional to the intensity-weighted wavevector known as optical current. The ability to design the optical current according to the considered application brings new promising perspectives to exploit the radiation pressure. However, this is a challenging problem because it often requires confinement of the optical current within tight light curves (circuits) and adapting its local value for a particular task. Here, we present a formalism to handle this problem including its experimental demonstration. It consists of a Nature-inspired circuit shaping with independent control of the optical current provided by a new kind of beam referred to as polymorphic beam. This finding is highly relevant to diverse optical technologies and can be easily extended to electron and x-ray coherent beams.

  16. Arbitrarily modulated beam for phase-only optical encryption

    NASA Astrophysics Data System (ADS)

    Chen, Wen; Chen, Xudong

    2014-10-01

    Optical encryption has attracted more and more attention recently due to its remarkable advantages, such as parallel processing and multiple-dimensional characteristics. In this paper, we propose to apply an arbitrarily modulated beam for phase-only optical encryption. In optical security systems, the plane wave is commonly used for the illumination, and unauthorized receivers may easily obtain or estimate the information related to the illumination beam. The proposed strategy with an arbitrarily modulated illumination beam can effectively enhance system security, since a beam modulation pattern (such as a pinhole-array pattern or a random phase-only pattern) can be considered an additional security key. The phase-only optical encryption is taken as an example for illustrating the validity of the proposed method; however it could be straightforward to apply the proposed strategy to other optical security systems.

  17. Polymorphic beams and Nature inspired circuits for optical current.

    PubMed

    Rodrigo, José A; Alieva, Tatiana

    2016-10-13

    Laser radiation pressure is a basis of numerous applications in science and technology such as atom cooling, particle manipulation, material processing, etc. This light force for the case of scalar beams is proportional to the intensity-weighted wavevector known as optical current. The ability to design the optical current according to the considered application brings new promising perspectives to exploit the radiation pressure. However, this is a challenging problem because it often requires confinement of the optical current within tight light curves (circuits) and adapting its local value for a particular task. Here, we present a formalism to handle this problem including its experimental demonstration. It consists of a Nature-inspired circuit shaping with independent control of the optical current provided by a new kind of beam referred to as polymorphic beam. This finding is highly relevant to diverse optical technologies and can be easily extended to electron and x-ray coherent beams.

  18. Method to improve optical parametric oscillator beam quality

    DOEpatents

    Smith, Arlee V.; Alford, William J.; Bowers, Mark S.

    2003-11-11

    A method to improving optical parametric oscillator (OPO) beam quality having an optical pump, which generates a pump beam at a pump frequency greater than a desired signal frequency, a nonlinear optical medium oriented so that a signal wave at the desired signal frequency and a corresponding idler wave are produced when the pump beam (wave) propagates through the nonlinear optical medium, resulting in beam walk off of the signal and idler waves, and an optical cavity which directs the signal wave to repeatedly pass through the nonlinear optical medium, said optical cavity comprising an equivalently even number of non-planar mirrors that produce image rotation on each pass through the nonlinear optical medium. Utilizing beam walk off where the signal wave and said idler wave have nonparallel Poynting vectors in the nonlinear medium and image rotation, a correlation zone of distance equal to approximately .rho.L.sub.crystal is created which, through multiple passes through the nonlinear medium, improves the beam quality of the OPO output.

  19. Separating and combining single-mode and multimode optical beams

    SciTech Connect

    Ruggiero, Anthony J; Masquelier, Donald A; Cooke, Jeffery B; Kallman, Jeffery S

    2013-11-12

    Techniques for combining initially separate single mode and multimode optical beams into a single "Dual Mode" fiber optic have been developed. Bi-directional propagation of two beams that are differentiated only by their mode profiles (i.e., wavefront conditions) is provided. The beams can be different wavelengths and or contain different modulation information but still share a common aperture. This method allows the use of conventional micro optics and hybrid photonic packaging techniques to produce small rugged packages suitable for use in industrial or military environments.

  20. Optical trapping of nanotubes with cylindrical vector beams.

    PubMed

    Donato, M G; Vasi, S; Sayed, R; Jones, P H; Bonaccorso, F; Ferrari, A C; Gucciardi, P G; Maragò, O M

    2012-08-15

    We use laser beams with radial and azimuthal polarization to optically trap carbon nanotubes. We measure force constants and trap parameters as a function of power showing improved axial trapping efficiency with respect to linearly polarized beams. The analysis of the thermal fluctuations highlights a significant change in the optical trapping potential when using cylindrical vector beams. This enables the use of polarization states to shape optical traps according to the particle geometry, as well as paving the way to nanoprobe-based photonic force microscopy with increased performance compared to a standard linearly polarized configuration.

  1. Special diffractive elements for optical trapping fabricated on optical fiber tips using the focused ion beam

    NASA Astrophysics Data System (ADS)

    Rodrigues Ribeiro, R. S.; Guerreiro, A.; Viegas, J.; Jorge, P. A. S.

    2016-05-01

    In this work, spiral phase lenses and Fresnel zone lenses for beam tailoring, fabricated on the tip of optical fibers, are reported. The spiral phase lenses allow tailoring the fundamental guided mode, a Gaussian beam, into a Laguerre - Gaussian profile without using additional optical elements. Whereas, the Fresnel lenses are used as focusing systems. The lenses are fabricated using Focused Ion Beam milling, enabling high resolution in the manufacturing process. The output optical intensity profiles matching the numerical simulations are presented and analyzed.

  2. Beam splitter and method for generating equal optical path length beams

    DOEpatents

    Qian, Shinan; Takacs, Peter

    2003-08-26

    The present invention is a beam splitter for splitting an incident beam into first and second beams so that the first and second beams have a fixed separation and are parallel upon exiting. The beam splitter includes a first prism, a second prism, and a film located between the prisms. The first prism is defined by a first thickness and a first perimeter which has a first major base. The second prism is defined by a second thickness and a second perimeter which has a second major base. The film is located between the first major base and the second major base for splitting the incident beam into the first and second beams. The first and second perimeters are right angle trapezoidal shaped. The beam splitter is configured for generating equal optical path length beams.

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

    NASA Technical Reports Server (NTRS)

    Jennings, Donald

    2013-01-01

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

  4. Optical Synchrotron Radiation Beam Imaging with a Digital Mask

    SciTech Connect

    Fiorito, R. B.; Zhang, H. D.; Corbett, W. J.; Fisher, A. S.; Mok, W. Y.; Tian, K.; Douglas, D.; Wilson, F. G.; Zhang, S.; Mitsuhashi, T. M.; Shkvarunets, A. G.

    2012-11-01

    We have applied a new imaging/optical masking technique, which employs a digital micro-mirror device (DMD) and optical synchrotron radiation (OSR), to perform high dynamic range (DR) beam imaging at the JLAB Energy Recovery Linac and the SLAC/SPEAR3 Synchrotron Light Source. The OSR from the beam is first focused onto the DMD to produce a primary image; selected areas of this image are spatially filtered by controlling the state of individual micro-mirrors; and finally, the filtered image is refocused onto a CCD camera. At JLAB this technique has been used successfully to view the beam halo with a DR ~ 105. At SPEAR3 the DMD was used to filter out the bright core of the stored beam to study the turn-by-turn dynamics of the 10-3 weaker injected beam. We describe the optical performance, present limitations and our plans to improve the DR of both experimental systems.

  5. CO2 laser beam propagation with ZnSe optics

    NASA Astrophysics Data System (ADS)

    Leong, K. H.; Liu, Yi; Holdridge, D. J.

    Beam propagation characteristics of ZnSe optics used in kiloWatt power CO2 laser aided material processing applications are determined using the Prometec Laser Beam Analyzer. The laser used was a Rofin Sinar RS6000 CO2 laser with mode aperturing. Beam power varied from 500W to 6300W and beam modes used were TEM(sub 00), TEM(sub 01), TEM(sub 10), and TEM(sub 20). Both transmissive and reflective optics were examined. The ZnSe lenses tested included meniscus, diffractive, and cylindrical lenses of 5 in. focal length and a 10 in. focal length integrating lens. Reflective optics included an integrator and a 5 in. focal length parabolic mirror for welding. Parameters obtained included beam propagation profiles, intensity profiles, depth of focus, spot size, and back focal length. A subset of the data obtained is presented here. Details of the work will appear in a full length paper.

  6. Optics Studies of the LHC Beam Transfer Line TI8

    SciTech Connect

    J. Wenninger; G. Arduini; B. Goddard; D. Jacquet; V. Kain; M. Lamont; V. Mertens; J.A. Uythoven; Y.-C. Chao

    2005-05-16

    The optics of the newly commissioned LHC beam transfer line TI 8 was studied with beam trajectories, dispersion and profile measurements. Steering magnet response measurements were used to analyze the quality of the steering magnets and of the beam position monitors. A simultaneous fit of the quadrupole strengths was used to search for setting or calibration errors. Residual coupling between the planes was evaluated using high statistics samples of trajectories. Initial conditions for the optics at the entrance of the transfer line were reconstructed from beam profile measurements with Optical Transition Radiation monitors. The paper presents the various analysis methods and their errors. The expected emittance growth arising from optical mismatch into the LHC is evaluated.

  7. Optical beam transport system at FEL-SUT

    NASA Astrophysics Data System (ADS)

    Nomaru, K.; Kawai, M.; Yokoyama, M.; Oda, F.; Nakayama, A.; Koike, H.; Kuroda, H.

    2000-05-01

    Kawasaki Heavy Industries Ltd. has installed an FEL beam transport system at the IR FEL Research Center of the Science University of Tokyo (FEL-SUT). This system transports the FEL output beam from the FEL machine room to the optical diagnostic room through a vacuum tube. The in-vacuum multi-mirror synchronized system operated from the FEL control room enables the operator to control the multiple mirrors simultaneously on or off axis of the FEL beam and to distribute the FEL output to one of the laboratories. The essential component of the transport system is the passive control optics that is composed of an elliptical and parabolic mirror couple. Once the control optics is aligned, a parallel FEL beam with a good pointing stability is obtained without any active operation to tune the optical system for different wavelengths.

  8. Production of accelerating quad Airy beams and their optical characteristics.

    PubMed

    Ren, Zhijun; Wu, Qiong; Shi, Yile; Chen, Chen; Wu, Jiangmiao; Wang, Hui

    2014-06-16

    Based on a geometric caustic argument and diffraction catastrophe theory, we generate a novel form of accelerating beams using a symmetric 3/2 phase-only pattern. Such beams can be called accelerating quad Airy beams (AQABs) because they look very much like four face-to-face combined Airy beams. Optical characteristics of AQABs are subsequently investigated. The research results show that the beams have axial-symmetrical and centrosymmetrical transverse intensity patterns and quasi-diffraction-free propagation features for their four main lobes while undergoing transverse shift along parabolic trajectories. Moreover, we also demonstrate that AQABs possess self-construction ability when local areas are blocked. The unique optical properties of these beams will make them useful tools for future scientific applications.

  9. Singular optical manipulation of birefringent elastic media using nonsingular beams.

    PubMed

    Brasselet, Etienne

    2009-10-15

    It is shown that nonsingular light beams can generate singular birefringent patterns in homogeneous birefringent elastic media. These orientational defects of the optical-axis spatial distribution originate from an optical torque driven by a nonzero longitudinal field component. Singular radial and spin-dependent azimuthal light-induced elastic distortion patterns are described and experimentally observed in a uniform liquid-crystal film in the course of a focused circularly polarized Gaussian beam.

  10. Integrated Electro-optical Laser-Beam Scanners

    NASA Technical Reports Server (NTRS)

    Boord, Warren T.

    1990-01-01

    Scanners using solid-state devices compact, consume little power, and have no moving parts. Integrated electro-optical laser scanner, in conjunction with external lens, points outgoing beam of light in any number of different directions, depending on number of upper electrodes. Offers beam-deflection angles larger than those of acousto-optic scanners. Proposed for such diverse applications as nonimpact laser printing, color imaging, ranging, barcode reading, and robotic vision.

  11. Feedback control of optical beam spatial profiles using thermal lensing.

    PubMed

    Liu, Zhanwei; Fulda, Paul; Arain, Muzammil A; Williams, Luke; Mueller, Guido; Tanner, D B; Reitze, D H

    2013-09-10

    A method for active control of the spatial profile of a laser beam using adaptive thermal lensing is described. A segmented electrical heater was used to generate thermal gradients across a transmissive optical element, resulting in a controllable thermal lens. The segmented heater also allows the generation of cylindrical lenses, and provides the capability to steer the beam in both horizontal and vertical planes. Using this device as an actuator, a feedback control loop was developed to stabilize the beam size and position.

  12. Optical two-beam trap in a polymer microfluidic chip

    NASA Astrophysics Data System (ADS)

    Espina Palanco, Marta; Catak, Darmin; Marie, Rodolphe; Matteucci, Marco; Bilenberg, Brian; Kristensen, Anders; Berg-Sørensen, Kirstine

    2016-09-01

    An optical two-beam trap, composed from two counter propagating laser beams, is an interesting setup due to the ability of the system to trap, hold, and stretch soft biological objects like vesicles or single cells. Because of this functionality, the system was also named "the optical stretcher" by Jochen Guck, Josep Käs and co-workers some 15 years ago. In a favorable setup, the two opposing laser beams meet with equal intensities in the middle of a fluidic channel in which cells may flow past, be trapped, stretched, and allowed to move on, giving the promise of a high throughput device. Yet, single beam optical traps, aka optical tweezers, by far outnumber the existing optical stretchers in research labs throughout the world. The ability to easily construct an optical stretcher setup in a low-cost material would possibly imply more frequent use of the optical stretching technique. Here, we will outline the design, the production procedures, and results obtained in a fiber-based experimental setup built within an injection molded microfluidic polymer chip. The microfluidic chip is constructed with a three layer technology in which we ensure both horizontal and vertical focusing of the cells we wish to trap, thereby preventing too many cells to flow below the line of focus of the two counter propagating laser beams that are positioned perpendicular to the direction of flow of the cells. Results will be compared to that from other designs from previous work in the group.

  13. Quadrant-division technique for differential sensitivity optical beam measurement

    NASA Astrophysics Data System (ADS)

    Hii, K. U.

    2016-11-01

    A novel method for optical beam collimation measurement is presented. The collimating lens is utilized in four parts of quadrants with the beam aligned onto the first quadrant and configured to pass the subsequent quadrants. This allows the test beam to pass the collimating lens for four times. Subsequently, the test beam is reversed to achieve a total number of eight passes. Hence, for a defocus introduced, the collimation state of the test beam can be evaluated at the amplification of eight. The evaluation of the test beam is performed based on the approach of collimation testing using lateral shearing interferometer. The proposed technique provides a differential collimation sensitivity for accurate setting of a highly collimated beam.

  14. Nonlinear optical beam interactions in waveguide arrays.

    PubMed

    Meier, Joachim; Stegeman, George I; Silberberg, Y; Morandotti, R; Aitchison, J S

    2004-08-27

    We report our investigation of Kerr nonlinear beam interactions in discrete systems. The influence of power and the relative phase between two Gaussian shaped beams was investigated in detail by performing numerical simulations of the discrete nonlinear Schrödinger equation and comparing the results with experiments done in AlGaAs waveguide arrays. Good agreement between theory and experiment was obtained.

  15. Propagation-induced polarization changes in partially coherent optical beams.

    PubMed

    Agrawal, G P; Wolf, E

    2000-11-01

    Propagation of a partially coherent optical beam inside a linear, nondispersive, dielectric medium is studied, taking into account the vector nature of the electromagnetic field. Propagation-induced polarization changes are studied by using the Gaussian-Schell model for the cross-spectral-density tensor. The degree of polarization changes with propagation and also becomes nonuniform across the beam cross section. The extent of these changes depends on the coherence radius associated with the cross-correlation function. For optical beams with symmetric spectra, the bandwidth of the source spectra is found to play a relatively minor role.

  16. A beam halo monitor based on adaptive optics

    NASA Astrophysics Data System (ADS)

    Welsch, C. P.; Bravin, E.; Lefèvre, T.

    2007-06-01

    In future high intensity, high energy accelerators, beam losses have to be minimized to maximize performance and reduce activation of accelerator components. It is imperative to have a clear understanding of the mechanisms that can lead to halo formation and to have the possibility to test available theoretical models with an adequate experimental setup. Measurements based on optical transition radiation (OTR) provide an interesting opportunity for high resolution measurements of the transverse beam profile. An imaging system based on a beam core-suppression technique, in which the core of the beam is deflected by means of a micro mirror array, to allow for direct observation of the halo has been developed. In this contribution, a possible layout of a novel diagnostic system based on adaptive optics is presented and the results of first tests carried out in our optical lab are summarized.

  17. Trapping volume control in optical tweezers using cylindrical vector beams.

    PubMed

    Skelton, S E; Sergides, M; Saija, R; Iatì, M A; Maragó, O M; Jones, P H

    2013-01-01

    We present the result of an investigation into the optical trapping of spherical microparticles using laser beams with a spatially inhomogeneous polarization direction [cylindrical vector beams (CVBs)]. We perform three-dimensional tracking of the Brownian fluctuations in the position of a trapped particle and extract the trap spring constants. We characterize the trap geometry by the aspect ratio of spring constants in the directions transverse and parallel to the beam propagation direction and evaluate this figure of merit as a function of polarization angle. We show that the additional degree of freedom present in CVBs allows us to control the optical trap strength and geometry by adjusting only the polarization of the trapping beam. Experimental results are compared with a theoretical model of optical trapping using CVBs derived from electromagnetic scattering theory in the T-matrix framework.

  18. Resonant diffraction gratings for spatial differentiation of optical beams

    SciTech Connect

    Golovastikov, N V; Bykov, D A; Doskolovich, L L

    2014-10-31

    Diffraction of a two-dimensional optical beam from a resonant diffraction grating is considered. It is shown that at certain resonance parameters the diffraction grating allows for spatial differentiation and integration of the incident beam. The parameters of the diffraction grating for spatial differentiation of optical beams in the transmission geometry are calculated. It is shown that the differentiating diffraction grating allows the conversion of the two-dimensional beam into the two-dimensional Hermite – Gaussian mode. The presented results of numerical modelling are in good agreement with the proposed theoretical description. The use of the considered resonant diffraction gratings is promising for solving the problems of all-optical data processing. (laser applications and other topics in quantum electronics)

  19. Miniature electron microscope beam column optics

    NASA Astrophysics Data System (ADS)

    Loyd, Jody Stuart

    This investigation is in the area of electrostatic lens design with the overarching goal of contributing to the creation of a miniaturized scanning electron microscope (SEM) for use in mineralogical analysis or detection of signs of life on the surface of Mars. Such an instrument could also have application in the exploration of Earth's moon, planetary moons, asteroids, or comets. Other embodiments could include tabletop or field portable SEMs for use on Earth. The scope of this research is in the design of a beam column that attains focusing, demagnification, and aberration control within the smallest achievable package. The goals of planetary exploration and of spaceflight in general impose severe constraints on the instrument's mass and electrical power consumption, while favoring a robust design of small size and high rigidity that is also simple to align. To meet these requirements a design using electrostatic lenses was favored because of the lower power requirement and mass of electrostatic versus magnetic lenses, their relatively simple construction, as well as inherently easier shielding from extraneous fields. In modeling the lens field, a hybrid of a Boundary Element Method (BEM) and a Fourier series solution was employed, whereby an initial solution from the BEM is used to derive the bounding potential of a cylindrical subdomain for the subsequent Fourier series solution. The approach is applicable to many problems in physics and combines the inherent precision of this series solution with the flexibility of BEM to describe practical, non-idealized electrode shapes. The resulting lens field in the Fourier series subdomain is of higher precision, thereby allowing smaller errors in subsequent calculations of electron ray paths. The effects of aberrations are thus easier to observe in tracing non-paraxial rays. A significant speed increase in tracing rays is also observed. The modeling technique has been validated by reproducing example ray-traces through

  20. Application of optical beams to electrons in graphene

    SciTech Connect

    Matulis, A.; Masir, M. Ramezani; Peeters, F. M.

    2011-03-15

    The technique of beam optics is applied to the description of the wave function of Dirac electrons. This approach is illustrated by considering electron transmission through simple nonhomogeneous structures, such as flat and bent p-n junctions and superlattices. We found that a convex p-n junction compresses the beam waist, while a concave interface widens it without loosing its focusing properties. At a flat p-n junction the waist of the transmitted Gaussian beam can be narrowed or widened, depending on the angle of incidence. A general condition is derived for the occurrence of beam collimation in a superlattice which is less stringent than previous discussed.

  1. Bessel-like optical beams with arbitrary trajectories.

    PubMed

    Chremmos, Ioannis D; Chen, Zhigang; Christodoulides, Demetrios N; Efremidis, Nikolaos K

    2012-12-01

    A method is proposed for generating Bessel-like optical beams with arbitrary trajectories in free space. The method involves phase-modulating an optical wavefront so that conical bundles of rays are formed whose apexes write a continuous focal curve with pre-specified shape. These ray cones have circular bases on the input plane; thus their interference results in a Bessel-like transverse field profile that propagates along the specified trajectory with a remarkably invariant main lobe. Such beams can be useful as hybrids between non-accelerating and accelerating optical waves that share diffraction-resisting and self-healing properties.

  2. Automatic Optical Crack Tracking for Double Cantilever Beam Specimens

    DTIC Science & Technology

    2015-01-01

    TECHN ICAL ART IC LE Automatic Optical Crack Tracking for Double Cantilever Beam Specimens B. Krull1,2, J. Patrick2,3, K. Hart2,4, S. White2,4, and N...computer program with edge detection software rapidly, automatically, and accurately tracks the crack front in translucent DCB specimens by optically ...through the DCB, crack length is optically determined from hand-marked delineations along the profile (side) of each sample. Continuous crack length

  3. Freeform optical design of an XY-zoom beam expander

    NASA Astrophysics Data System (ADS)

    Duerr, Fabian; Thienpont, Hugo

    2016-04-01

    Laser sources have become indispensable for industrial materials processing applications. These applications are accompanied with a variety of different demands and requirements on the delivered laser irradiance distributions. With a high spatial uniformity, top-hat beams provide benefits for applications like surface heat treatment or welding, in which it is desirable to uniformly illuminate a target surface. Some applications might not only favor a specific beam irradiance distribution but can benefit additionally from time-varying distributions. In this work, we present the analytic design of an XY-zoom beam expander based on movable freeform optics that allows to simultaneously vary the magnification in x- and y-direction, respectively. This optical functionality is not new; what is new is the idea that axially moving freeform lenses are used to achieve such an optical functionality by optimally exploiting the additional degrees of freedom that freeform surfaces offer. The developed analytic solution is fully described by very few initial parameters and does allow an increasingly accurate calculation of four freeform lenses described by high order XY Taylor polynomial surfaces. Moreover, this solution approach can be adapted to cope with additional optical surfaces and/or lens groups to further enhance the overall optical performance. In comparison with (existing) combinations of rotated cylindrically symmetric zoom beam expanders, such a freeform system consists of less optical elements and provides a much more compact solution, yet achieving excellent overall optical performance throughout the full range of zoom positions.

  4. Laser beacon adaptive optics for power beaming applications

    SciTech Connect

    Fugate, R.Q.

    1994-12-31

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

  5. Engineering of automated assembly of beam-shaping optics

    NASA Astrophysics Data System (ADS)

    Haag, Sebastian; Sinhoff, Volker; Müller, Tobias; Brecher, Christian

    2014-03-01

    Beam-shaping is essential for any kind of laser application. Assembly technologies for beam-shaping subassemblies are subject to intense research and development activities and their technical feasibility has been proven in recent years while economic viability requires more efficient engineering tools for process planning and production ramp up of complex assembly tasks for micro-optical systems. The work presented in this paper aims for significant reduction of process development and production ramp up times for the automated assembly of micro-optical subassemblies for beam-collimation and beam-tilting. The approach proposed bridges the gap between the product development phase and the realization of automation control through integration of established software tools such as optics simulation and CAD modeling as well as through introduction of novel software tools and methods to efficiently describe active alignment strategies. The focus of the paper is put on the methodological approach regarding the engineering of assembly processes for beam-shaping micro-optics and the formal representation of assembly objectives similar to representation in mechanical assemblies. Main topic of the paper is the engineering methodology for active alignment processes based on the classification of optical functions for beam-shaping optics and corresponding standardized measurement setups including adaptable alignment algorithms. The concepts are applied to industrial use-cases: (1) integrated collimation module for fast- and slow-axis and (2) beam-tilting subassembly consisting of a fast-axis collimator and micro-lens array. The paper concludes with an overview of current limitations as well as an outlook on the next development steps considering adhesive bonding processes.

  6. Rapid Process to Generate Beam Envelopes for Optical System Analysis

    NASA Technical Reports Server (NTRS)

    Howard, Joseph; Seals, Lenward

    2012-01-01

    The task of evaluating obstructions in the optical throughput of an optical system requires the use of two disciplines, and hence, two models: optical models for the details of optical propagation, and mechanical models for determining the actual structure that exists in the optical system. Previous analysis methods for creating beam envelopes (or cones of light) for use in this obstruction analysis were found to be cumbersome to calculate and take significant time and resources to complete. A new process was developed that takes less time to complete beam envelope analysis, is more accurate and less dependent upon manual node tracking to create the beam envelopes, and eases the burden on the mechanical CAD (computer-aided design) designers to form the beam solids. This algorithm allows rapid generation of beam envelopes for optical system obstruction analysis. Ray trace information is taken from optical design software and used to generate CAD objects that represent the boundary of the beam envelopes for detailed analysis in mechanical CAD software. Matlab is used to call ray trace data from the optical model for all fields and entrance pupil points of interest. These are chosen to be the edge of each space, so that these rays produce the bounding volume for the beam. The x and y global coordinate data is collected on the surface planes of interest, typically an image of the field and entrance pupil internal of the optical system. This x and y coordinate data is then evaluated using a convex hull algorithm, which removes any internal points, which are unnecessary to produce the bounding volume of interest. At this point, tolerances can be applied to expand the size of either the field or aperture, depending on the allocations. Once this minimum set of coordinates on the pupil and field is obtained, a new set of rays is generated between the field plane and aperture plane (or vice-versa). These rays are then evaluated at planes between the aperture and field, at a

  7. Interference from multiple trapped colloids in an optical vortex beam.

    PubMed

    Lee, W M; Garcés-Chávez, V; Dholakia, K

    2006-08-07

    Laguerre-Gaussian (LG) beams are important in optical micromanipulation. We show that optically trapped microparticles within a monochromatic LG beam may lead to the formation of unique intensity patterns in the far field due to multiple interference of the forward scattered light from each particle. Trapped colloids create far field interference that exhibits distinct spiral wave patterns that are directly correlated to the helicity of the LG beam. Using two trapped particles, we demonstrate the first microscopic version of a Young's slits type experiment and detect the azimuthal phase variation around the LG beam circumference. This novel technique may be implemented to study the relative phase and spatial coherence of two points in trapping light fields with arbitrary wavefronts.

  8. Ion-beam machining of millimeter scale optics.

    PubMed

    Shanbhag, P M; Feinberg, M R; Sandri, G; Horenstein, M N; Bifano, T G

    2000-02-01

    An ion-beam microcontouring process is developed and implemented for figuring millimeter scale optics. Ion figuring is a noncontact machining technique in which a beam of high-energy ions is directed toward a target substrate to remove material in a predetermined and controlled fashion. Owing to this noncontact mode of material removal, problems associated with tool wear and edge effects, which are common in conventional machining processes, are avoided. Ion-beam figuring is presented as an alternative for the final figuring of small (<1-mm) optical components. The depth of the material removed by an ion beam is a convolution between the ion-beam shape and an ion-beam dwell function, defined over a two-dimensional area of interest. Therefore determination of the beam dwell function from a desired material removal map and a known steady beam shape is a deconvolution process. A wavelet-based algorithm has been developed to model the deconvolution process in which the desired removal contours and ion-beam shapes are synthesized numerically as wavelet expansions. We then mathematically combined these expansions to compute the dwell function or the tool path for controlling the figuring process. Various models have been developed to test the stability of the algorithm and to understand the critical parameters of the figuring process. The figuring system primarily consists of a duo-plasmatron ion source that ionizes argon to generate a focused (approximately 200-microm FWHM) ion beam. This beam is rastered over the removal surface with a perpendicular set of electrostatic plates controlled by a computer guidance system. Experimental confirmation of ion figuring is demonstrated by machining a one-dimensional sinusoidal depth profile in a prepolished silicon substrate. This profile was figured to within a rms error of 25 nm in one iteration.

  9. Update on POCIT portable optical communicators: VideoBeam and EtherBeam

    NASA Astrophysics Data System (ADS)

    Mecherle, G. Stephen; Holcomb, Terry L.

    2000-05-01

    LDSC is developing the POCITTM (Portable Optical Communication Integrated Transceiver) family of products which includes VideoBeamTM and the latest addition, EtherBeamTM. Each is a full duplex portable laser communicator: VideoBeamTM providing near-broadcast- quality analog video and stereo audio, and EtherBeamTM providing standard Ethernet connectivity. Each POCITTM transceiver consists of a 3.5-pound unit with a binocular- type form factor, which can be manually pointed, tripod- mounted or gyro-stabilized. Both units have an operational range of over two miles (clear air) with excellent jam- resistance and low probability of interception characteristics. The transmission wavelength of 1550 nm enables Class 1 eyesafe operation (ANSI, IEC). The POCITTM units are ideally suited for numerous military scenarios, surveillance/espionage, industrial precious mineral exploration, and campus video teleconferencing applications. VideoBeam will be available second quarter 2000, followed by EtherBeam in third quarter 2000.

  10. Beaconless adaptive-optics technique for HEL beam control

    NASA Astrophysics Data System (ADS)

    Khizhnyak, Anatoliy; Markov, Vladimir

    2016-05-01

    Effective performance of forthcoming laser systems capable of power delivery on a distant target requires an adaptive optics system to correct atmospheric perturbations on the laser beam. The turbulence-induced effects are responsible for beam wobbling, wandering, and intensity scintillation, resulting in degradation of the beam quality and power density on the target. Adaptive optics methods are used to compensate for these negative effects. In its turn, operation of the AOS system requires a reference wave that can be generated by the beacon on the target. This report discusses a beaconless approach for wavefront correction with its performance based on the detection of the target-scattered light. Postprocessing of the beacon-generated light field enables retrieval and detailed characterization of the turbulence-perturbed wavefront -data that is essential to control the adaptive optics module of a high-power laser system.

  11. Optical two-beam traps in microfluidic systems

    NASA Astrophysics Data System (ADS)

    Berg-Sørensen, Kirstine

    2016-08-01

    An attractive solution for optical trapping and stretching by means of two counterpropagating laser beams is to embed waveguides or optical fibers in a microfluidic system. The microfluidic system can be constructed in different materials, ranging from soft polymers that may easily be cast in a rapid prototyping manner, to hard polymers that could even be produced by injection moulding, or to silica in which waveguides may either be written directly, or with grooves for optical fibers. Here, we review different solutions to the system and also show results obtained in a polymer chip with DUV written waveguides and in an injection molded polymer chip with grooves for optical fibers.

  12. Optical homodyne tomography of information carrying laser beams

    NASA Astrophysics Data System (ADS)

    Wu, Jinwei; Lam, Ping Koy; Gray, Malcolm; Bachor, Hans Albert

    1998-08-01

    Optical homodyne tomography (OHT) is a tool that allows the reconstruction of Wigner functions for each detection frequency of a propagating optical beam. It can measure probability distribution functions (PDF's) of the field amplitude for any given quadrature of interest. We demonstrate OHT for a range of classical optical states with constant and time varying modulations and show the advantage of OHT over conventional homodyne detection. The OHT simultaneously determines the signal to noise ratio in both amplitude and phase quadratures. We show that highly non-Gaussian Wigner functions can be obtained from incoherent superpositions of optical states.

  13. Beam optical design of in-flight fragment separator for high-power heavy ion beam

    NASA Astrophysics Data System (ADS)

    Yun, C. C.; Kim, Mi-Jung; Kim, D. G.; Song, J. S.; Kim, Myeong-Jin; Kim, J. W.; Kim, J. R.; Wan, W.

    2013-12-01

    An in-flight fragment separator has been designed for the rare isotope science project (RISP) in Korea. A beam used for the design is 238U in the energy of 200 MeV/u with the maximum beam power of 400 kW. The use of high-power beam requires careful removal of the primary beam by pre-separator, for which its configuration was revised to employ four dipole magnets instead of two. Different configurations of the separator have been tested in search of optimal design in non-linear optics, which was complicated by the space needed for the target, beam dump and radiation shielding. Non-linear optical calculations have been carried out using GICOSY and COSY Infinity including the fringe fields of large-aperture quadrupole magnets. Correction of non-linear terms is made with multipole coils located inside the superconducting quadrupole magnets and by external multipole magnets. Beam simulations using LISE++ and MOCADI have been performed to consider the effects of multiple charge states of the primary and isotope beams produced at the target. Layout of the separator is being finalized, and detailed optics simulation will continue to refine its design.

  14. Broadband reconfigurable optical beam-forming systems

    NASA Astrophysics Data System (ADS)

    Toughlian, Edward N.; Zmuda, Henry; Carter, Charity A.

    1994-06-01

    It is shown that by applying spatial frequency dependent optical phase compensation in an optical heterodyne process, variable RF delay can be achieved over a prescribed frequency band. Experimental results that demonstrate the performance of the delay line with regard to both maximum delay and resolution over a broad bandwidth are presented. Additionally, a spatially integrated optical system is proposed for control of phased array antennas, providing mechanical stability, essentially eliminating the drift problems associated with free-space optical systems, and providing high packing density. This approach uses a class of SLM known as a deformable mirror device and leads to a steerable arbitrary antenna radiation pattern of the true time-delay type. Also considered is the ability to utilize the delay line as a general photonic signal processing element in an adaptive (reconfigurable) transversal frequency filter configuration. Such systems are widely applicable in jammer/noise canceling systems, broadband ISDN, spread spectrum secure communications and the like.

  15. Laser absorption velocimetry using an optical vortex beam

    NASA Astrophysics Data System (ADS)

    Yoshimura, Shinji; Aramaki, Mitsutoshi; Ozawa, Naoya; Terasaka, Kenichiro; Tanaka, Masayoshi; Morisaki, Tomohiro

    2016-09-01

    A plain-wave-like beam, or a Hermite-Gaussian mode, has been used for conventional laser spectroscopy. Since the Doppler shift in frequency of light absorbed by a moving atom is given by the dot product of the wave vector of the light beam and an atomic velocity, it is essentially a one-dimensional measurement. It has a merit that the interpretation of the result is clear and straightforward; however, it simultaneously poses a limitation that the measurable velocity component is confined to the projection along the wave vector. This limitation may be overcome by using an optical vortex beam, or a Laguerre-Gaussian mode, which has helical phase fronts associated with orbital angular momentum of light. Due to its three-dimensional phase structure, the Doppler shift for an atom moving in the optical vortex beam has three components. Therefore, the laser measurement method that has a sensitivity even for transverse motion across the beam is possible to be achieved. We have performed laser absorption measurements using optical vortex beams as a proof-of-principle experiment, where an additional frequency shift in the absorption spectra of metastable argon neutrals in a plasma has been observed. The details of experimental results will be discussed in the conference. This study was partially supported by JSPS KAKENHI Grand Numbers 15K05365 and 25287152.

  16. Electro-optic voltage sensor with beam splitting

    DOEpatents

    Woods, Gregory K.; Renak, Todd W.; Davidson, James R.; Crawford, Thomas M.

    2002-01-01

    The invention is a miniature electro-optic voltage sensor system capable of accurate operation at high voltages without use of the dedicated voltage dividing hardware typically found in the prior art. The invention achieves voltage measurement without significant error contributions from neighboring conductors or environmental perturbations. The invention employs a transmitter, a sensor, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor. Within the sensor the beam undergoes the Pockels electro-optic effect. The electro-optic effect produces a modulation of the beam's polarization, which is in turn converted to a pair of independent conversely-amplitude-modulated signals, from which the voltage of the E-field is determined by the signal processor. The use of converse AM signals enables the signal processor to better distinguish signal from noise. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  17. Electro-optic voltage sensor with Multiple Beam Splitting

    DOEpatents

    Woods, Gregory K.; Renak, Todd W.; Crawford, Thomas M.; Davidson, James R.

    2000-01-01

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages without use of the dedicated voltage dividing hardware. The invention achieves voltage measurement without significant error contributions from neighboring conductors or environmental perturbations. The invention employs a transmitter, a sensor, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor. Within the sensor the beam undergoes the Pockels electro-optic effect. The electro-optic effect produces a modulation of the beam's polarization, which is in turn converted to a pair of independent conversely-amplitude-modulated signals, from which the voltage of the E-field is determined by the signal processor. The use of converse AM signals enables the signal processor to better distinguish signal from noise. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  18. Elongated optical bottle beams generated by composite binary axicons

    NASA Astrophysics Data System (ADS)

    Porfirev, A. P.; Skidanov, R. V.

    2016-04-01

    We provide analytical, numerical and experimental study of the possibility of forming elongated optical bottle beams (OBBs) using composite binary phase axicons. In this case, the OBB is generated by the superposition of Bessel beams in the near-field region on the axicon. To generate the OBB experimentally, we utilized a spatial light modulator. The experimental results are qualitatively consistent with the results of numerical simulations performed using Fresnel transform. Such type of optical trap can be applied in many applications of microbiology, micromechanics and meteorology to manipulate micro- and nanoobjects in liquid or gaseous medium.

  19. How orbital angular momentum affects beam shifts in optical reflection

    SciTech Connect

    Merano, M.; Hermosa, N.; Woerdman, J. P.; Aiello, A.

    2010-08-15

    It is well known that reflection of a Gaussian light beam (TEM{sub 00}) by a planar dielectric interface leads to four beam shifts when compared to the geometrical-optics prediction. These are the spatial Goos-Haenchen (GH) shift, the angular GH shift, the spatial Imbert-Fedorov (IF) shift, and the angular IF shift. We report here, theoretically and experimentally, that endowing the beam with orbital angular momentum leads to coupling of these four shifts; this is described by a 4x4 mixing matrix.

  20. Multimode laser beam analyzer instrument using electrically programmable optics.

    PubMed

    Marraccini, Philip J; Riza, Nabeel A

    2011-12-01

    Presented is a novel design of a multimode laser beam analyzer using a digital micromirror device (DMD) and an electronically controlled variable focus lens (ECVFL) that serve as the digital and analog agile optics, respectively. The proposed analyzer is a broadband laser characterization instrument that uses the agile optics to smartly direct light to the required point photodetectors to enable beam measurements of minimum beam waist size, minimum waist location, divergence, and the beam propagation parameter M(2). Experimental results successfully demonstrate these measurements for a 500 mW multimode test laser beam with a wavelength of 532 nm. The minimum beam waist, divergence, and M(2) experimental results for the test laser are found to be 257.61 μm, 2.103 mrad, 1.600 and 326.67 μm, 2.682 mrad, 2.587 for the vertical and horizontal directions, respectively. These measurements are compared to a traditional scan method and the results of the beam waist are found to be within error tolerance of the demonstrated instrument.

  1. Beam shaping in flow cytometry with diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Qu, Weidong; Li, Derong; Jian, Peng

    2016-10-01

    Focusing elements are usually employed in the flow cytometry to focus the input laser beam into elliptically shaped Gaussian beam in order to increase power for excitation of fluorescence for high signal-to-noise ratio (SNR). While in order to ensure repeatable and reliable signal generation for accurate population discrimination - despite slight deviations of the cell from the flow centre, the shaped beam should be a cubic diffraction region with uniform power intensity across the cell flow stream. However, it is hard for beam shaping with refractive optical elements. In this paper, we present a beam shaping system in flow cytometry with diffractive optical elements (DOEs) to shape the input laser beam to a cubic diffraction region with uniform power intensity. The phase distribution of the DOE is obtained by using the inverse Fresnel diffraction based layered holographic stereogram, and the cubic diffraction region with uniform power intensity within the cell flow channel is well reconstructed. Simulation results demonstrate the good performance of the new beam shaping system.

  2. Parallel beam optical tomography apparatus for 3D radiation dosimetry

    NASA Astrophysics Data System (ADS)

    Krstajic, Nikola; Doran, Simon J.

    2005-06-01

    Since the discovery of X rays radiotherapy has had the same aim - to deliver a precisely measured dose of radiation to a defined tumour volume with minimal damage to surrounding healthy tissue. Recent developments in radiotherapy such as intensity modulated radiotherapy (IMRT) can generate complex shapes of dose distributions. Until recently it has not been possible to verify that the delivered dose matches the planned dose. However, one often wants to know the real three-dimensional dose distribution. Three-dimensional radiation dosimeters have been developed since the early 1980s. Most chemical formulations involve a radiosensitive species immobilised in space by gelling agent. Magnetic Resonance Imaging (MRI) and optical techniques have been the most successful gel scanning techniques so far. Optical techniques rely on gels changing colour once irradiated. Parallel beam optical tomography has been developed at the University of Surrey since the late 1990s. The apparatus involves light emitting diode light source collimated to a wide (12cm) parallel beam. The beam is attenuated or scattered (depending on the chemical formulation) as it passes through the gel. Focusing optics projects the beam onto a CCD chip. The dosimeter sits on a rotation stage. The tomography scan involves continuously rotating the dosimeter and taking CCD images. Once the dosimeter has been rotated over 180 degrees the images are processed by filtered back projection. The work presented discusses the optics of the apparatus in more detail.

  3. Single beam optical vortex tweezers with tunable orbital angular momentum

    SciTech Connect

    Gecevičius, Mindaugas; Drevinskas, Rokas Beresna, Martynas; Kazansky, Peter G.

    2014-06-09

    We propose a single beam method for generating optical vortices with tunable optical angular momentum without altering the intensity distribution. With the initial polarization state varying from linear to circular, we gradually control the torque transferred to the trapped non-absorbing and non-birefringent silica beads. The continuous transition from the maximum rotation speed to zero without changing the trapping potential gives a way to study the complex tribological interactions.

  4. Optical and control modeling for adaptive beam-combining experiments

    SciTech Connect

    Gruetzner, J.K.; Tucker, S.D.; Neal, D.R.; Bentley, A.E.; Simmons-Potter, K.

    1995-08-01

    The development of modeling algorithms for adaptive optics systems is important for evaluating both performance and design parameters prior to system construction. Two of the most critical subsystems to be modeled are the binary optic design and the adaptive control system. Since these two are intimately related, it is beneficial to model them simultaneously. Optic modeling techniques have some significant limitations. Diffraction effects directly limit the utility of geometrical ray-tracing models, and transform techniques such as the fast fourier transform can be both cumbersome and memory intensive. The authors have developed a hybrid system incorporating elements of both ray-tracing and fourier transform techniques. In this paper they present an analytical model of wavefront propagation through a binary optic lens system developed and implemented at Sandia. This model is unique in that it solves the transfer function for each portion of a diffractive optic analytically. The overall performance is obtained by a linear superposition of each result. The model has been successfully used in the design of a wide range of binary optics, including an adaptive optic for a beam combining system consisting of an array of rectangular mirrors, each controllable in tip/tilt and piston. Wavefront sensing and the control models for a beam combining system have been integrated and used to predict overall systems performance. Applicability of the model for design purposes is demonstrated with several lens designs through a comparison of model predictions with actual adaptive optics results.

  5. Further Analysis of Real Beam Line Optics From A Synthetic Beam

    SciTech Connect

    Ryan Bodenstein, Michael Tiefenback, Yves Roblin

    2012-07-01

    Standard closed-orbit techniques for Twiss parameter measurement are not applicable to the open-ended Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab. The evolution of selected sets of real orbits in the accelerator models the behavior of a 'synthetic' beam. This process will be validated against beam profile-based Twiss parameter measurements and should provide the distributed optical information needed to optimize beamline tuning for an open-ended system. This work will discuss the current and future states of this technique, as well as an example of its use in the CEBAF machine.

  6. Focusing Light Beams To Improve Atomic-Vapor Optical Buffers

    NASA Technical Reports Server (NTRS)

    Strekalov, Dmitry; Matsko, Andrey; Savchenkov, Anatoliy

    2010-01-01

    Specially designed focusing of light beams has been proposed as a means of improving the performances of optical buffers based on cells containing hot atomic vapors (e.g., rubidium vapor). There is also a companion proposal to improve performance by use of incoherent optical pumping under suitable conditions. Regarding the proposal to use focusing: The utility of atomic-vapor optical buffers as optical storage and processing devices has been severely limited by nonuniform spatial distributions of intensity in optical beams, arising from absorption of the beams as they propagate in atomic-vapor cells. Such nonuniformity makes it impossible to optimize the physical conditions throughout a cell, thereby making it impossible to optimize the performance of the cell as an optical buffer. In practical terms simplified for the sake of brevity, "to optimize" as used here means to design the cell so as to maximize the group delay of an optical pulse while keeping the absorption and distortion of the pulse reasonably small. Regarding the proposal to use incoherent optical pumping: For reasons too complex to describe here, residual absorption of light is one of the main impediments to achievement of desirably long group delays in hot atomic vapors. The present proposal is directed toward suppressing residual absorption of light. The idea of improving the performance of slow-light optical buffers by use of incoherent pumping overlaps somewhat with the basic idea of Raman-based slow-light systems. However, prior studies of those systems did not quantitatively answer the question of whether the performance of an atomic vapor or other medium that exhibits electromagnetically induced transparency (EIT) with Raman gain is superior to that of a medium that exhibits EIT without Raman gain.

  7. Generation of diffraction-free optical beams using wrinkled membranes

    PubMed Central

    Li, Ran; Yi, Hui; Hu, Xiao; Chen, Leng; Shi, Guangsha; Wang, Weimin; Yang, Tian

    2013-01-01

    Wrinkling has become a well developed bottom-up technique to make artificial surface textures in about the last decade. However, application of the optical properties of long range ordered wrinkles has been limited to one dimensional gratings to date. We report the demonstration of macroscopic optical focusing using wrinkled membranes, in which concentric wrinkle rings on a gold-PDMS bilayer membrane convert collimated illuminations to diffraction-free focused beams. Beam diameters of 300–400 μm have been observed in the visible range, which are dominantly limited by the eccentricity of the current devices. Based upon agreement between theoretical and experimental results on eccentricity effects, we predict a decrease of the beam diameter to no more than around 50 μm, if eccentricity is eliminated. PMID:24072139

  8. Terahertz beam steering using interference of femtosecond optical pulses.

    PubMed

    Uematsu, Koji; Maki, Ken-ichiro; Otani, Chiko

    2012-09-24

    A terahertz (THz) beam steering method is demonstrated by applying the characteristic of grating lobe (GL) radiation from a linear array antenna and the interference of femtosecond optical pulses. A photoconductive device is illuminated by two femtosecond laser beams combined at an angle of less than 0.5°. Considering the interference pattern as a THz point source array, THz GL radiation is generated through the superposition of radiation emitted from all point sources and steered by varying the interval of the interference pattern. The THz beam direction could be changed by 20° at 0.93THz by varying the relative incidence angle of the pump beams by 0.033°.

  9. Optical Frequency Domain Visualization of Electron Beam Driven Plasma Wakefields

    NASA Astrophysics Data System (ADS)

    Zgadzaj, Rafal; Downer, M. C.; Muggli, Patric; Yakimenko, Vitaly; Babzien, Marcus; Kusche, Karl; Fedurin, Mikhail

    2010-11-01

    Beam-driven plasma wakefield accelerators (PWFA), such as the ``plasma afterburner,'' are a promising approach for significantly increasing the particle energies of conventional accelerators. The study and optimization of PWFA would benefit from an experimental correlation between the parameters of the drive bunch, the accelerated bunch and the corresponding, accelerating plasma wave structure. However, the plasma wave structure has not yet been observed directly in PWFA. We will report our current work on noninvasive optical Frequency Domain Interferometric (FDI) and Holographic (FDH) visualization of beam-driven plasma waves. Both techniques employ two laser pulses (probe and reference) co-propagating with the particle drive-beam and its plasma wake. The reference pulse precedes the drive bunch, while the probe overlaps the plasma wave and maps its longitudinal and transverse structure. The experiment is being developed at the BNL/ATF Linac to visualize wakes generated by two and multi-bunch drive beams.

  10. Design method for automotive high-beam LED optics

    NASA Astrophysics Data System (ADS)

    Byzov, Egor V.; Moiseev, Mikhail A.; Doskolovich, Leonid L.; Kazanskiy, Nikolay L.

    2015-09-01

    New analytical method for the calculation of the LED secondary optics for automotive high-beam lamps is presented. Automotive headlamps should illuminate the road and the curb at the distance of 100-150 meters and create a bright, flat, relatively powerful light beam. To generate intensity distribution of this kind we propose to use TIR optical element (collimator working on the total internal reflection principle) with array of microlenses (optical corrector) on the upper surface. TIR part of the optical element enables reflection of the side rays to the front direction and provides a collimated beam which incidents on the microrelief. Microrelief, in its turn, dissipates the light flux in horizontal direction to meet the requirements of the Regulations 112, 113 and to provide well-illuminated area across the road in the far field. As an example, we computed and simulated the optical element with the diameter of 33 millimeters and the height of 22 millimeters. Simulation data shows that three illuminating modules including Cree XP-G2 LED and lens allow generating an appropriate intensity distribution for the class D of UNECE Regulations.

  11. Total reflection of optical beams by weakly oscillating dielectric scatterers

    NASA Astrophysics Data System (ADS)

    Granot, Er'el

    2016-12-01

    It is well known that in quantum mechanics a weak scatterer can act as a perfect reflector provided it oscillates at a specific frequency, which is close to that of the incident particles. This is a Fano resonance, in which case the propagating wave mode destructively interferes with the bound state. Due to the high frequencies of the optical domain, it is not possible to design an optical device, which is based on this effect. However, if the beam propagates in a narrow waveguide with conducting boundaries, then even a weak dielectric scatterer, which oscillates at the frequency difference between the optical frequency and the threshold frequency of the waveguide, can block the optical beam. This frequency difference can be arbitrarily small. A model for such a system is presented and solved exactly numerically without approximations. For a weak scatterer an approximate analytical expression is suggested for the point of perfect reflection. Finally, a physical realization is suggested. This effect can be used for controlling optical beams by submicron devices.

  12. Optical beam-shaping design based on aspherical lenses for circularization, collimation, and expansion of elliptical laser beams.

    PubMed

    Serkan, Mert; Kirkici, Hulya

    2008-01-10

    We present two optical system designs using aspherical lenses for beam circularization, collimation, and expansion of semiconductor lasers for possible application in lidar systems. Two different optical lens systems are investigated; namely, two aspherical lens and single aspherical lens systems. Software package programs of ZEMAX and MATLAB to simulate the optical designs are used. The beam reshaping results are presented for one specific laser beam output.

  13. Optical beam-shaping design based on aspherical lenses for circularization collimation, and expansion of elliptical laser beams

    NASA Astrophysics Data System (ADS)

    Serkan, Mert; Kirkici, Hulya

    2008-01-01

    We present two optical system designs using aspherical lenses for beam circularization, collimation, and expansion of semiconductor lasers for possible application in lidar systems. Two different optical lens systems are investigated; namely, two aspherical lens and single aspherical lens systems. Software package programs of ZEMAX and MATLAB to simulate the optical designs are used. The beam reshaping results are presented for one specific laser beam output.

  14. Quantitative comparison of single-beam gradient-force optical traps and dual-beam optical traps

    NASA Astrophysics Data System (ADS)

    Huang, Z. H.; Mehta, D. S.; Huang, H. C.; Wang, C. F.; Chiou, Arthur E. T.

    2000-07-01

    In this paper, we compare the performance of the single beam gradient-firce trap (SBGFT) and the counter propagating dual-beam trap (CPDBT) quantitively in terms of three performance parameters, namely, the transverse trapping efficiency, the width of the stable trapping zone, and the axial stiffness. Ray-Optics Model (for optical trapping of Mie particles) was used to obtain the numerical results. In the SBGFT, the particle is trapped in the vicinity of the focal spot of a strongly focused (N.A. ~ 0.65 to 1.3) laser beam by gradient forces in both the transverse and the axial directions. In the CPDBT, with the two counter- propagating beams often mildly focused (N.A. <0.6), the particle is confined transversely by the transverse gradient forces of the two beams and stabilized axially by balancing the scattering forces from the two beams. Depending on the separation between the two beam waists, there can be more than one stable trapping zones in the CPDBT. Qualitatively, one obvious key advantage of SBGFT is that it is very simple to implement. In contrast, the CPDBT requires precised alignment of the two beams. The latter, however, allows longer working distance and offers more degrees of freedom. The theoretical values of the aforementioned performance parameters for the CPDBT vary over a wide range because they depend on the distance between two beam waists. This extra degree of freedom in the CPDBT allows us to trade off one performance parameter against the others. We have also measured these performance parameters experimentally to verify the general trend predicted by the theoretical model.

  15. Self-accelerating fan-shaped beams along arbitrary trajectories: a new tool for optical manipulation

    NASA Astrophysics Data System (ADS)

    Sui, Xiaolin; Zhao, Juanying; Liu, Bo; Yan, Ziheng; Cao, Changdong; Zhou, Shouhuan

    2017-01-01

    We demonstrate, both theoretically and experimentally, a kind of fan-shaped optical beam propagating along the arbitrary trajectories (such as parabolic, hyperbolic and three-dimensional spiraling trajectories). With a controlled profile, this fan-shaped optical beam can be obtained from superposition of the Bessel-like beam and vortex Bessel-like beam. Also, the ability of guiding and transporting microparticles along its lobes is explored. These beams may find a variety of applications in optical trapping and manipulation.

  16. Dual Ion Beam Deposition Of Diamond Films On Optical Elements

    NASA Astrophysics Data System (ADS)

    Deutchman, Arnold H.; Partyka, Robert J.; Lewis, J. C.

    1990-01-01

    Diamond film deposition processes are of great interest because of their potential use for the formation of both protective as well as anti-reflective coatings on the surfaces of optical elements. Conventional plasma-assisted chemical vapor deposition diamond coating processes are not ideal for use on optical components because of the high processing temperatures required, and difficulties faced in nucleating films on most optical substrate materials. A unique dual ion beam deposition technique has been developed which now makes possible deposition of diamond films on a wide variety of optical elements. The new DIOND process operates at temperatures below 150 aegrees Farenheit, and has been used to nucleate and grow both diamondlike carbon and diamond films on a wide variety of optical :taterials including borosilicate glass, quartz glass, plastic, ZnS, ZnSe, Si, and Ge.

  17. A simple multipurpose double-beam optical image analyzer

    NASA Astrophysics Data System (ADS)

    Popowicz, A.; Blachowicz, T.

    2016-07-01

    In the paper we present a low cost optical device which splits the light in the focal plane into two separate optical paths and collimates it back into a single image plane, and where a selective information processing can be carried out. The optical system is straightforward and easily implementable as it consists of only three lenses and two mirrors. The system is dedicated for imaging in low-light-level conditions in which widely used optical devices, based on beam splitters or dichroic mirrors, suffer from light loss. We expose examples of applications of our device, using a prototype model. The proposed optical system may be employed for: monitoring the objects located at different distances from observer (1), creating regions of different magnification within a single image plane (2), high dynamic range photometry (3), or imaging in two wavelength bands simultaneously (4).

  18. An Alternative High Luminosity LHC with Flat Optics and Long-Range Beam-Beam Compensation

    SciTech Connect

    Fartoukh, Stephane; Valishev, Alexander; Shatilov, Dmitry

    2015-06-01

    In the baseline scenario of the High-Luminosity LHC (HL-LHC), the geometric loss of luminosity in the two high luminosity experiments due to collisions with a large crossing angle is recovered by tilting the bunches in the interaction region with the use of crab cavities. A possible backup scenario would rely on a reduced crossing angle together with flat optics (with different horizontal and vertical $\\beta^{\\ast}$values) for the preservation of luminosity performance. However, the reduction of crossing angle coupled with the flat optics significantly enhances the strength of long-range beam-beam interactions. This paper discusses the possibility to mitigate the long-range beam-beam effects by current bearing wire compensators (or e-lens). We develop a new HL-LHC parameter list and analyze it in terms of integrated luminosity performance as compared to the baseline. Further, we evaluate the operational scenarios using numerical simulations of single-particle dynamics with beam-beam effects.

  19. Beam shaping for laser-based adaptive optics in astronomy.

    PubMed

    Béchet, Clémentine; Guesalaga, Andrés; Neichel, Benoit; Fesquet, Vincent; González-Núñez, Héctor; Zúñiga, Sebastián; Escarate, Pedro; Guzman, Dani

    2014-06-02

    The availability and performance of laser-based adaptive optics (AO) systems are strongly dependent on the power and quality of the laser beam before being projected to the sky. Frequent and time-consuming alignment procedures are usually required in the laser systems with free-space optics to optimize the beam. Despite these procedures, significant distortions of the laser beam have been observed during the first two years of operation of the Gemini South multi-conjugate adaptive optics system (GeMS). A beam shaping concept with two deformable mirrors is investigated in order to provide automated optimization of the laser quality for astronomical AO. This study aims at demonstrating the correction of quasi-static aberrations of the laser, in both amplitude and phase, testing a prototype of this two-deformable mirror concept on GeMS. The paper presents the results of the preparatory study before the experimental phase. An algorithm to control amplitude and phase correction, based on phase retrieval techniques, is presented with a novel unwrapping method. Its performance is assessed via numerical simulations, using aberrations measured at GeMS as reference. The results predict effective amplitude and phase correction of the laser distortions with about 120 actuators per mirror and a separation of 1.4 m between the mirrors. The spot size is estimated to be reduced by up to 15% thanks to the correction. In terms of AO noise level, this has the same benefit as increasing the photon flux by 40%.

  20. Reactive ion beam figuring of optical aluminium surfaces

    NASA Astrophysics Data System (ADS)

    Bauer, Jens; Frost, Frank; Arnold, Thomas

    2017-03-01

    Ultra-smooth and arbitrarily shaped reflective optics are necessary for further progress in EUV/XUV lithography, x-ray and synchrotron technology. As one of the most important technological mirror optic materials, aluminium behaves in a rather difficult way in ultra-precision machining with such standard techniques as diamond-turning and subsequent ion beam figuring (IBF). In particular, in the latter, a strong surface roughening is obtained. Hence, up to now it has not been possible to attain the surface qualities required for UV or just visible spectral range applications. To overcome the limitations mainly caused by the aluminium alloy structural and compositional conditions, a reactive ion beam machining process using oxygen process gas is evaluated. To clarify the principle differences in the effect of oxygen gas contrary to oxygen ions on aluminium surface machining, we firstly focus on chemical-assisted ion beam etching (CAIBE) and reactive ion beam etching (RIBE) experiments in a phenomenological manner. Then, the optimum process route will be explored within a more quantitative analysis applying the concept of power spectral density (PSD) for a sophisticated treatment of the surface topography. Eventually, the surface composition is examined by means of dynamic secondary ion mass spectrometry (SIMS) suggesting a characteristic model scheme for the chemical modification of the aluminium surface during oxygen ion beam machining. Monte Carlo simulations were applied to achieve a more detailed process conception.

  1. Remote nano-optical beam focusing lens by illusion optics

    NASA Astrophysics Data System (ADS)

    Margousi, David; Shoorian, Hamed Reza

    2014-08-01

    In this paper, as a new application of illusion optics, a nano-optical plasmonic focusing lens structure is proposed to manipulate the light remotely by employing illusion optics theory. Plasmonic nano-optic lenses that enable super-focusing beyond the diffraction limit have been proposed as an alternative to the conventional dielectric-based refractive lenses. In the presence of an illusion device, the electromagnetic plane-waves can penetrate into a metal layer and a clear focus appears. When the illusion device is removed, waves are blocked to transmit through the metal wall. In comparison with conventional methods, our proposed method avoids any physical changes or damages in the original structure. The proposed structure can be realized by isotropic layered materials, using effective medium theory. The special feature of the proposed structure and the device concepts introduced in this work gives it an opportunity to be used as a flexible element in ultrahigh nano-scale integrated circuits for miniaturization and tuning purposes.

  2. Two-Photon-Absorption Scheme for Optical Beam Tracking

    NASA Technical Reports Server (NTRS)

    Ortiz, Gerardo G.; Farr, William H.

    2011-01-01

    A new optical beam tracking approach for free-space optical communication links using two-photon absorption (TPA) in a high-bandgap detector material was demonstrated. This tracking scheme is part of the canonical architecture described in the preceding article. TPA is used to track a long-wavelength transmit laser while direct absorption on the same sensor simultaneously tracks a shorter-wavelength beacon. The TPA responsivity was measured for silicon using a PIN photodiode at a laser beacon wavelength of 1,550 nm. As expected, the responsivity shows a linear dependence with incident power level. The responsivity slope is 4.5 x 10(exp -7) A/W2. Also, optical beam spots from the 1,550-nm laser beacon were characterized on commercial charge coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) imagers with as little as 13.7 microWatts of optical power (see figure). This new tracker technology offers an innovative solution to reduce system complexity, improve transmit/receive isolation, improve optical efficiency, improve signal-to-noise ratio (SNR), and reduce cost for free-space optical communications transceivers.

  3. Forked grating coupler optical vortex beam interface for silicon photonics

    NASA Astrophysics Data System (ADS)

    Nadovich, Christopher T.; Kosciolek, Derek J.; Jemison, William D.; Crouse, David T.

    2016-09-01

    The forked grating coupler (FGC) is a novel low-profile device compatible with silicon photonics that is capable of sensitive detection or efficient radiation of Optical Vortex (OV) light beams conveying orbital optical angular momentum (OAM). The FGC device combines the idea of a Bragg coupler with the forked hologram to create an integrated optics device that can selectively and efficiently couple selected optical vortex modes at near-normal incidence into planar confined dielectric waveguide modes of a photonic IC. FGCs retain many of the advantages of Bragg couplers, including convenience of placement and fabrication, reasonable bandwidth, small size, and CMOS process compatibility. In this work, prototype designs of FGC structures for 1550 nm wavelength have been developed for implementation on silicon on insulator (SOI) substrate. Fully vectorial three-dimensional (3D) electromagnetic simulation has allowed performance to be optimized over a range of structural parameters. Results have been evaluated against optical performance metrics including overall efficiency, mode match efficiency, and crosstalk between OV modes. Candidate FGC devices have been fabricated on SOI with e-beam lithography and tested optically. Tolerance to etch depth error has been evaluated.

  4. POCIT portable optical communicators: VideoBeam and EtherBeam

    NASA Astrophysics Data System (ADS)

    Mecherle, G. Stephen; Holcomb, Terry L.

    1999-12-01

    LDSC is developing the POCITTM (Portable Optical Communication Integrated Transceiver) family of products which now includes VideoBeamTM and the latest addition, EtherBeamTM. Each is a full duplex portable laser communicator: VideoBeamTM providing near-broadcast- quality analog video and stereo audio, and EtherBeamTM providing standard Ethernet connectivity. Each POCITTM transceiver consists of a 3.5-pound unit with a binocular- type form factor, which can be manually pointed, tripod- mounted or gyro-stabilized. Both units have an operational range of over two miles (clear air) with excellent jam- resistance and low probability of interception characteristics. The transmission wavelength of 1550 nm enables Class I eyesafe operation (ANSI, IEC). The POCITTM units are ideally suited for numerous miliary scenarios, surveillance/espionage, industrial precious mineral exploration, and campus video teleconferencing applications.

  5. Gaussian laser beam transformation into an optical vortex beam by helical lens

    NASA Astrophysics Data System (ADS)

    Janicijevic, Ljiljana; Topuzoski, Suzana

    2016-01-01

    In this article, we investigate the Fresnel diffraction characteristics of the hybrid optical element which is a combination of a spiral phase plate (SPP) with topological charge p and a thin lens with focal length f, named the helical lens (HL). As incident a Gaussian laser beam is treated, having its waist a distance ζ from the HL plane and its axis passing through the centre of the HL. It is shown that the SPP introduces a phase singularity of pth order to the incident beam, while the lens transforms the beam characteristic parameters. The output light beam is analyzed in detail: its characteristic parameters and focusing properties, amplitude and intensity distributions and the vortex rings profiles, and radii, at any z distance behind the HL plane, as well as in the near and far field.

  6. Efficient Optical Energy Harvesting in Self-Accelerating Beams

    PubMed Central

    Bongiovanni, Domenico; Hu, Yi; Wetzel, Benjamin; Robles, Raul A.; Mendoza González, Gregorio; Marti-Panameño, Erwin A.; Chen, Zhigang; Morandotti, Roberto

    2015-01-01

    We report the experimental observation of energetically confined self-accelerating optical beams propagating along various convex trajectories. We show that, under an appropriate transverse compression of their spatial spectra, these self-accelerating beams can exhibit a dramatic enhancement of their peak intensity and a significant decrease of their transverse expansion, yet retaining both the expected acceleration profile and the intrinsic self-healing properties. We found our experimental results to be in excellent agreement with the numerical simulations. We expect further applications in such contexts where power budget and optimal spatial confinement can be important limiting factors. PMID:26299360

  7. Beam propagation method analysis of optical waveguide lenses.

    PubMed

    Ishikawa, A; Izutsu, M; Sueta, T

    1990-12-01

    Focusing characteristics of optical waveguide lenses are analyzed by the beam propagation method (BPM) instead of the ray tracing method. By use of the BPM, we can observe field distributions of a converging or diverging light beam after it passes through a waveguide lens. Variations of the spot width and magnitude of diffraction can immediately be evaluated with this calculation. The BPM calculations are used for a mode-index, Luneburg, and geodesic lenses. For the application of the method to the geodesic lens, the surface deformation is converted into an equivalent index.

  8. Optical apparatus using liquid crystals for shaping the spatial intensity of optical beams having designated wavelengths

    DOEpatents

    Jacobs, S.D.; Cerqua, K.A.

    1987-07-14

    The spatial intensity profile of an optical beam of designated wavelengths, such as a laser beam, is shaped (the beam is apodized) by means of cholesteric liquid crystals of opposite chirality disposed successively along the path of the beam. The crystals have curved surfaces, which may be defined by a lens which defines the thickness of the liquid crystal fluid gap in a liquid crystal cell, so as to vary the selective reflection of the designated wavelength across the aperture of the beam. In this way, a soft aperture is provided. By using tandem cell pairs having liquid crystals of opposite chirality, but of different pitch, and with lenses of different curvature, beams of different wavelengths which are projected colinearly along the path may be individually tailored in spatial intensity profile. 11 figs.

  9. Optical apparatus using liquid crystals for shaping the spatial intensity of optical beams having designated wavelengths

    DOEpatents

    Jacobs, Stephen D.; Cerqua, Kathleen A.

    1987-01-01

    The spatial intensity profile of an optical beam of designated wavelengths, such as a laser beam, is shaped (the beam is apodized) by means of cholesteric liquid crystals of opposite chirality disposed successively along the path of the beam. The crystals have curved surfaces, which may be defined by a lens which defines the thickness of the liquid crystal fluid gap in a liquid crystal cell, so as to vary the selective reflection of the designated wavelength across the aperture of the beam. In this way, a soft aperture is provided. By using tandem cell pairs having liquid crystals of opposite chirality, but of different pitch, and with lenses of different curvature, beams of different wavelengths which are projected colinearly along the path may be individually tailored in spatial intensity profile.

  10. Adaptive beam shaping by controlled thermal lensing in optical elements.

    PubMed

    Arain, Muzammil A; Quetschke, Volker; Gleason, Joseph; Williams, Luke F; Rakhmanov, Malik; Lee, Jinho; Cruz, Rachel J; Mueller, Guido; Tanner, D B; Reitze, David H

    2007-04-20

    We describe an adaptive optical system for use as a tunable focusing element. The system provides adaptive beam shaping via controlled thermal lensing in the optical elements. The system is agile, remotely controllable, touch free, and vacuum compatible; it offers a wide dynamic range, aberration-free focal length tuning, and can provide both positive and negative lensing effects. Focusing is obtained through dynamic heating of an optical element by an external pump beam. The system is especially suitable for use in interferometric gravitational wave interferometers employing high laser power, allowing for in situ control of the laser modal properties and compensation for thermal lensing of the primary laser. Using CO(2) laser heating of fused-silica substrates, we demonstrate a focal length variable from infinity to 4.0 m, with a slope of 0.082 diopter/W of absorbed heat. For on-axis operation, no higher-order modes are introduced by the adaptive optical element. Theoretical modeling of the induced optical path change and predicted thermal lens agrees well with measurement.

  11. Two-beam interferometer with optical path difference magnified.

    PubMed

    Zhang, Liang; Lu, Ping; Liu, Deming; Zhang, Jiangshan; Wang, Shun; Wang, Dajian

    2013-01-15

    A two-beam interferometer is proposed and experimentally demonstrated with OPD magnified. Two cascaded fiber ring resonators with almost the same fiber length are spliced into a fiber loop. An acousto-optic modulator is employed to generate optical pulses and to choose the pulses traveling around one of the resonators for x trips. The interferometer is characterized in displacement in our experiment. Experimental results show the proportional relationship between the sensitivity and x. The high-sensitivity interferometer scheme is useful in some measurement applications that require high sensitivity, such as solid earth tide gauge.

  12. Force feedback microscopy based on an optical beam deflection scheme

    SciTech Connect

    Vitorino, Miguel V.; Rodrigues, Mario S.; Carpentier, Simon; Costa, Luca

    2014-07-07

    Force feedback microscopy circumvents the jump to contact in atomic force microscopy when using soft cantilevers and quantitatively measures the interaction properties at the nanoscale by simultaneously providing force, force gradient, and dissipation. The force feedback microscope developed so far used an optical cavity to measure the tip displacement. In this Letter, we show that the more conventional optical beam deflection scheme can be used to the same purpose. With this instrument, we have followed the evolution of the Brownian motion of the tip under the influence of a water bridge.

  13. Method to render second order beam optics programs symplectic

    SciTech Connect

    Douglas, D.; Servranckx, R.V.

    1984-10-01

    We present evidence that second order matrix-based beam optics programs violate the symplectic condition. A simple method to avoid this difficulty, based on a generating function approach to evaluating transfer maps, is described. A simple example illustrating the non-symplectricity of second order matrix methods, and the effectiveness of our solution to the problem, is provided. We conclude that it is in fact possible to bring second order matrix optics methods to a canonical form. The procedure for doing so has been implemented in the program DIMAT, and could be implemented in programs such as TRANSPORT and TURTLE, making them useful in multiturn applications. 15 refs.

  14. Fiber-optic holography employing multiple beam fringe stabilization and object/reference beam intensity variability.

    PubMed

    Muhs, J D; Leilabady, P A; Corke, M

    1988-09-01

    The use of fiber optics in the field of optical holography is discussed with emphasis on the design of systems used to overcome several inherent shortcomings associated with fiber-optic holographic systems. Specifically, random environmentally induced optical phase changes within the fiber are minimized by employing a Michelson interferometer in conjunction with a closed loop feedback system. Furthermore, by using several passive single-mode couplers, complete object illumination via several illumination fibers is observed. Finally, by implementing a Mach-Zehnder interferometric technique, control of the object and reference beam intensity ratios in a fiber-optic holographic system can be accomplished. The resulting schemes are very stable and highly versatile systems suitable for remote holographic interferometric sensing and other applications where conventional holography techniques are impractical. Experimental results on fringe visibility, fringe stability, and the stabilization of object/reference beam intensity ratios are also given along with a composite summary of the overall system constraints associated with fiber-optic holographic systems.

  15. Expanded beam non-imaging fiber optic connector

    DOEpatents

    Jannson, Tommasz; Jannson, Joanna; Yeung, Peter

    1990-01-01

    There is disclosed an expanded beam fiber to fiber connector, based on non-imaging optic principles for coupling light beams from one optical fiber to another. The system consists of two identical connector parts, referred to herein as a collimating part and a concentrating part, each having a preferred partially curved reflective boundary surface for minimizing power loss and surrounding either a hollow space or a space filled with a uniform transparent medium. In one embodiment the boundary is metallic while in a second embodiment the boundary is in the form of an interface allowing total internal reflection. In both the hollow and filled case a lens may be located at the expanded end of both the collimater part and the concentrator part forming the connector. The connector is preferably located in a housing in order to protect and preserve the mechanical stability of the coupler.

  16. Expanded beam non-imaging fiber optic connector

    DOEpatents

    Jannson, T.; Jannson, J.; Yeung, P.

    1990-02-06

    There is disclosed an expanded beam fiber to fiber connector, based on non-imaging optic principles for coupling light beams from one optical fiber to another. The system consists of two identical connector parts, referred to herein as a collimating part and a concentrating part, each having a preferred partially curved reflective boundary surface for minimizing power loss and surrounding either a hollow space or a space filled with a uniform transparent medium. In one embodiment the boundary is metallic while in a second embodiment the boundary is in the form of an interface allowing total internal reflection. In both the hollow and filled case a lens may be located at the expanded end of both the collimator part and the concentrator part forming the connector. The connector is preferably located in a housing in order to protect and preserve the mechanical stability of the coupler. 13 figs.

  17. Optical observations of the beam-plasma discharge phenomenon

    NASA Technical Reports Server (NTRS)

    Sivjee, G. G.; Hamwey, R. M.; Hallinan, T. J.

    1993-01-01

    Spectroscopic observations of optical emissions from the beam-plasma discharge (BPD) phenomenon were made with NASA's vacuum chamber facility, at the Johnson Space Center, configured to simulate the physical conditions of magnetospheric electron beam injection into the ionospheric/upper-atmospheric environment. Nonlinear N2 and N2(+) optical emission growth rates (with respect to incremental electron beam current values) were observed from the chamber gas during transition to the BPD state. For electron-beam currents (I) near the BPD transition value (I(sub c)), the band emissions from the chamber gas produced by relatively low energy (less than or equal to 50 eV) electrons interacting with N2 were anomalously more intense than those requiring higher energy (greater than 100 eV) electrons to excite them. For I more greater than I(sub c), the optical emissions increased linearly with I (as was the case for I less than I(sub c)) and their ratios decreased significantly from the peak values attained when I approximately equals I(sub c). These observations suggest that during BPD some of the energy of the primary electron beam is efficiently transferred, via wave-particle interactions, to local electrons produced through ionization of the chamber gas; the resulting suprathermal electrons provide an additional source of excitation for the relatively low energy states (A, B and C) of N2. Such nonlinear excitation of upper atmospheric gas may occur in certain auroral events wherein the current due to the precipitating electrons approaches a value close to I(sub c).

  18. Alignment of optical system components using an ADM beam through a null assembly

    NASA Technical Reports Server (NTRS)

    Hayden, Joseph E. (Inventor); Olczak, Eugene G. (Inventor)

    2010-01-01

    A system for testing an optical surface includes a rangefinder configured to emit a light beam and a null assembly located between the rangefinder and the optical surface. The null assembly is configured to receive and to reflect the emitted light beam toward the optical surface. The light beam reflected from the null assembly is further reflected back from the optical surface toward the null assembly as a return light beam. The rangefinder is configured to measure a distance to the optical surface using the return light beam.

  19. Structural design considerations for the beam transmission optical system

    NASA Astrophysics Data System (ADS)

    MacNeal, Paul D.; Lou, Michael C.

    1993-04-01

    The paper describes the JPL study leading to a baseline design of the Beam Transmission Optical System (BTOS), designed for the delivery of laser energy from earth to space targets. The study identified the driving environmental and functional requirements; developed a conceptual design of the BTOS telescope; and performed static, thermal distortion, and model analyses to verify that these requirements are met. The study also identified major areas of concern which should be investigated further.

  20. EQUAL OPTICAL PATH BEAM SPLITTERS BY USE OF AMPLITUDE-SPLITTING AND WAVEFRONT-SPLITTING METHODS FOR PENCIL BEAM INTERFEROMETER.

    SciTech Connect

    QIAN,S.TAKACS,P.

    2003-08-03

    A beam splitter to create two separated parallel beams is a critical unit of a pencil beam interferometer, for example the long trace profiler (LTP). The operating principle of the beam splitter can be based upon either amplitude-splitting (AS) or wavefront-splitting (WS). For precision measurements with the LTP, an equal optical path system with two parallel beams is desired. Frequency drift of the light source in a non-equal optical path system will cause the interference fringes to drift. An equal optical path prism beam splitter with an amplitude-splitting (AS-EBS) beam splitter and a phase shift beam splitter with a wavefront-splitting (WS-PSBS) are introduced. These beam splitters are well suited to the stability requirement for a pencil beam interferometer due to the characteristics of monolithic structure and equal optical path. Several techniques to produce WS-PSBS by hand are presented. In addition, the WS-PSBS using double thin plates, made from microscope cover plates, has great advantages of economy, convenience, availability and ease of adjustment over other beam splitting methods. Comparison of stability measurements made with the AS-EBS, WS-PSBS, and other beam splitters is presented.

  1. Optically induced rotation of Rayleigh particles by vortex beams with different states of polarization

    NASA Astrophysics Data System (ADS)

    Li, Manman; Yan, Shaohui; Yao, Baoli; Liang, Yansheng; Lei, Ming; Yang, Yanlong

    2016-01-01

    Optical vortex beams carry optical orbital angular momentum (OAM) and can induce an orbital motion of trapped particles in optical trapping. We show that the state of polarization (SOP) of vortex beams will affect the details of this optically induced orbital motion to some extent. Numerical results demonstrate that focusing the vortex beams with circular, radial or azimuthal polarizations can induce a uniform orbital motion on a trapped Rayleigh particle, while in the focal field of the vortex beam with linear polarization the particle experiences a non-uniform orbital motion. Among the formers, the vortex beam with circular polarization induces a maximum optical torque on the particle. Furthermore, by varying the topological charge of the vortex beams, the vortex beam with circular polarization gives rise to an optimum torque superior to those given by the other three vortex beams. These facts suggest that the circularly polarized vortex beam is more suitable for rotating particles.

  2. Optical microscope using an interferometric source of two-color, two-beam entangled photons

    DOEpatents

    Dress, William B.; Kisner, Roger A.; Richards, Roger K.

    2004-07-13

    Systems and methods are described for an optical microscope using an interferometric source of multi-color, multi-beam entangled photons. A method includes: downconverting a beam of coherent energy to provide a beam of multi-color entangled photons; converging two spatially resolved portions of the beam of multi-color entangled photons into a converged multi-color entangled photon beam; transforming at least a portion of the converged multi-color entangled photon beam by interaction with a sample to generate an entangled photon specimen beam; and combining the entangled photon specimen beam with an entangled photon reference beam within a single beamsplitter. An apparatus includes: a multi-refringent device providing a beam of multi-color entangled photons; a condenser device optically coupled to the multi-refringent device, the condenser device converging two spatially resolved portions of the beam of multi-color entangled photons into a converged multi-color entangled photon beam; a beam probe director and specimen assembly optically coupled to the condenser device; and a beam splitter optically coupled to the beam probe director and specimen assembly, the beam splitter combining an entangled photon specimen beam from the beam probe director and specimen assembly with an entangled photon reference beam.

  3. Improvements in neutron beam applications by using capillary neutron optics

    NASA Astrophysics Data System (ADS)

    Downing, Robert G.; Xiao, Qi-Fan; Sharov, V. A.; Ponomarev, Igor Y.; Ullrich, Johannes B.; Gibson, David M.; Chen-Mayer, Huaiyu H.; Mildner, David F. R.; Lamaze, G. P.

    1997-02-01

    Capillary neutron optics improve the capabilities of neutron beam techniques such as neutron depth profiling and prompt gamma activation analysis. Millions of glass capillaries are configured to capture and guide low-energy neutrons by grazing total reflection from the smooth inner surface of the hollow channels. By precise orientation of the capillaries, beams of neutrons are readily collimated with good angular control or can be finely focused - as required by the application. In addition, the optics can improve the signal-to-noise ratio by diverting a neutron beam to a convenient off-axis direction, thereby circumventing interferences from gamma rays and fast neutrons characteristic of simple aperture collimation. The focused intensity of neutrons obtained in an area of 0.03 mm2 may be increased up to a hundred times over that previously available for NDP or PGAA techniques. Furthermore, the spatial resolution can be improved by up to 100 times. Consequently, small samples, or small volumes within larger samples, may be better and more rapidly investigated with neutron probe techniques. We report on developments in the application of capillary neutron optics.

  4. Fast character projection electron beam lithography for diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Harzendorf, Torsten; Fuchs, Frank; Banasch, Michael; Zeitner, Uwe D.

    2014-05-01

    Electron beam lithography becomes attractive also for the fabrication of large scale diffractive optical elements by the use of the character projection (CP) technique. Even in the comparable fast variable shaped beam (VSB) exposure approach for conventional electron beam writers optical nanostructures may require very long writing times exceeding 24 hours per wafer because of the high density of features, as required by e.g. sub-wavelength nanostructures. Using character projection, the writing time can be reduced by more than one order of magnitude, due to the simultaneous exposure of multiple features. The benefit of character projection increases with increasing complexity of the features and decreasing period. In this contribution we demonstrate the CP technique for a grating of hexagonal symmetry at 350nm period. The pattern is designed to provide antireflective (AR) properties, which can be adapted in their spectral and angular domain for applications from VIS to NIR by changing the feature size and the etching depth of the nanostructure. This AR nanostructure can be used on the backside of optical elements e.g. gratings, when an AR coating stack could not be applied for the reason of climatic conditions or wave front accuracy.

  5. Multiple Optical Traps with a Single-Beam Optical Tweezer Utilizing Surface Micromachined Planar Curved Grating

    NASA Astrophysics Data System (ADS)

    Kuo, Ju-Nan; Chen, Kuan-Yu

    2010-11-01

    In this paper, we present a single-beam optical tweezer integrated with a planar curved diffraction grating for microbead manipulation. Various curvatures of the surface micromachined planar curved grating are systematically investigated. The planar curved grating was fabricated using multiuser micro-electro-mechanical-system (MEMS) processes (MUMPs). The angular separation and the number of diffracted orders were determined. Experimental results indicate that the diffraction patterns and curvature of the planar curved grating are closely related. As the curvature of the planar curved grating increases, the vertical diffraction angle increases, resulting in the strip patterns of the planar curved grating. A single-beam optical tweezer integrated with a planar curved diffraction grating was developed. We demonstrate a technique for creating multiple optical traps from a single laser beam using the developed planar curved grating. The strip patterns of the planar curved grating that resulted from diffraction were used to trap one row of polystyrene beads.

  6. Electro-Optic Beam Steering Using Non-Linear Organic Materials

    DTIC Science & Technology

    1993-08-01

    York (SUNY), Buffalo, for potential application to the Hughes electro - optic beam deflector device. Evaluations include electro - optic coefficient...response time, transmission, and resistivity. Electro - optic coefficient measurements were made at 633 nm using a simple reflection technique. The

  7. Improved Oxygen-Beam Texturing of Glucose-Monitoring Optics

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.

    2006-01-01

    An improved method has been devised for using directed, hyperthermal beams of oxygen atoms and ions to impart desired textures to the tips of polymethylmethacrylate [PMMA] optical fibers to be used in monitoring the glucose content of blood. The improved method incorporates, but goes beyond, the method described in Texturing Blood-Glucose- Monitoring Optics Using Oxygen Beams (LEW-17642-1), NASA Tech Briefs, Vol. 29, No. 4 (April 2005), page 11a. The basic principle of operation of such a glucose-monitoring sensor is as follows: The textured surface of the optical fiber is coated with chemicals that interact with glucose in such a manner as to change the reflectance of the surface. Light is sent down the optical fiber and is reflected from, the textured surface. The resulting change in reflectance of the light is measured as an indication of the concentration of glucose. The required texture on the ends of the optical fibers is a landscape of microscopic cones or pillars having high aspect ratios (microscopic structures being taller than they are wide). The average distance between hills must be no more than about 5 mso that blood cells (which are wider) cannot enter the valleys between the hills, where they would interfere with optical sensing of glucose in the blood plasma. On the other hand, the plasma is required to enter the valleys, and high aspect ratio structures are needed to maximize the surface area in contact with the plasma, thereby making it possible to obtain a given level of optical glucose-measurement sensitivity with a relatively small volume of blood. There is an additional requirement that the hills be wide enough that a sufficient amount of light can propagate into them and, after reflection, can propagate out of them. The method described in the cited prior article produces a texture comprising cones and pillars that conform to the average-distance and aspect-ratio requirements. However, a significant fraction of the cones and pillars are so

  8. System for generating shaped optical pulses and measuring optical pulses using spectral beam deflection (SBD)

    DOEpatents

    Skupsky, Stanley; Kessler, Terrance J.; Letzring, Samuel A.

    1993-01-01

    A temporally shaped or modified optical output pulse is generated from a bandwidth-encoded optical input pulse in a system in which the input pulse is in the form of a beam which is spectrally spread into components contained within the bandwidth, followed by deflection of the spectrally spread beam (SBD) thereby spatially mapping the components in correspondence with the temporal input pulse profile in the focal plane of a lens, and by spatially selective attenuation of selected components in that focal plane. The shaped or modified optical output pulse is then reconstructed from the attenuated spectral components. The pulse-shaping system is particularly useful for generating optical pulses of selected temporal shape over a wide range of pulse duration, such pulses finding application in the fields of optical communication, optical recording and data storage, atomic and molecular spectroscopy and laser fusion. An optical streak camera is also provided which uses SBD to display the beam intensity in the focal plane as a function of time during the input pulse.

  9. System for generating shaped optical pulses and measuring optical pulses using spectral beam deflection (SBD)

    DOEpatents

    Skupsky, S.; Kessler, T.J.; Letzring, S.A.

    1993-11-16

    A temporally shaped or modified optical output pulse is generated from a bandwidth-encoded optical input pulse in a system in which the input pulse is in the form of a beam which is spectrally spread into components contained within the bandwidth, followed by deflection of the spectrally spread beam (SBD) thereby spatially mapping the components in correspondence with the temporal input pulse profile in the focal plane of a lens, and by spatially selective attenuation of selected components in that focal plane. The shaped or modified optical output pulse is then reconstructed from the attenuated spectral components. The pulse-shaping system is particularly useful for generating optical pulses of selected temporal shape over a wide range of pulse duration, such pulses finding application in the fields of optical communication, optical recording and data storage, atomic and molecular spectroscopy and laser fusion. An optical streak camera is also provided which uses SBD to display the beam intensity in the focal plane as a function of time during the input pulse. 10 figures.

  10. Two-dimensional beam steering using a thermo-optic silicon photonic optical phased array

    NASA Astrophysics Data System (ADS)

    Rabinovich, William S.; Goetz, Peter G.; Pruessner, Marcel W.; Mahon, Rita; Ferraro, Mike S.; Park, Doe; Fleet, Erin; DePrenger, Michael J.

    2016-11-01

    Many components for free-space optical (FSO) communication systems have shrunken in size over the last decade. However, the steering systems have remained large and power hungry. Nonmechanical beam steering offers a path to reducing the size of these systems. Optical phased arrays can allow integrated beam steering elements. One of the most important aspects of an optical phased array technology is its scalability to a large number of elements. Silicon photonics can potentially offer this scalability using CMOS foundry techniques. A phased array that can steer in two dimensions using the thermo-optic effect is demonstrated. No wavelength tuning of the input laser is needed and the design allows a simple control system with only two inputs. A benchtop FSO link with the phased array in both transmit and receive mode is demonstrated.

  11. Fiber optic reference frequency distribution to remote beam waveguide antennas

    NASA Technical Reports Server (NTRS)

    Calhoun, Malcolm; Kuhnle, Paul; Law, Julius

    1995-01-01

    In the NASA/JPL Deep Space Network (DSN), radio science experiments (probing outer planet atmospheres, rings, gravitational waves, etc.) and very long-base interferometry (VLBI) require ultra-stable, low phase noise reference frequency signals at the user locations. Typical locations for radio science/VLBI exciters and down-converters are the cone areas of the 34 m high efficiency antennas or the 70 m antennas, located several hundred meters from the reference frequency standards. Over the past three years, fiber optic distribution links have replaced coaxial cable distribution for reference frequencies to these antenna sites. Optical fibers are the preferred medium for distribution because of their low attenuation, immunity to EMI/IWI, and temperature stability. A new network of Beam Waveguide (BWG) antennas presently under construction in the DSN requires hydrogen maser stability at tens of kilometers distance from the frequency standards central location. The topic of this paper is the design and implementation of an optical fiber distribution link which provides ultra-stable reference frequencies to users at a remote BWG antenna. The temperature profile from the earth's surface to a depth of six feet over a time period of six months was used to optimize the placement of the fiber optic cables. In-situ evaluation of the fiber optic link performance indicates Allan deviation on the order of parts in 10(exp -15) at 1000 and 10,000 seconds averaging time; thus, the link stability degradation due to environmental conditions still preserves hydrogen maser stability at the user locations. This paper reports on the implementation of optical fibers and electro-optic devices for distributing very stable, low phase noise reference signals to remote BWG antenna locations. Allan deviation and phase noise test results for a 16 km fiber optic distribution link are presented in the paper.

  12. Theory of optical beam deflection for single microparticles

    NASA Astrophysics Data System (ADS)

    Wu, Jiaqi; Kitamori, Takehiko; Sawada, Tsuguo

    1991-05-01

    A theory was developed for the optical beam deflection (OBD) signal generated from a single microparticle. From the thermal-diffusion equations, the temperature fields inside and outside the microparticle, which has a two-layer structure, was deduced. A three-dimensional theoretical treatment was established for the deflection signal of the probe beam passing through the temperature field formed by photothermal conversion of the excitation beam energy absorbed by the sample. The proprieties of the theoretical model and its results were confirmed by comparing the theoretical values of the frequency characteristics, probe beam offset dependencies, and particle size dependencies of the OBD signal with the experimental ones for 25-300-μm-radius microparticles. From the theory, the unique particle size dependencies and frequency characteristics of the OBD method for the single microparticle, i.e., higher sensitivity for smaller particles and at high frequencies, were identified as due to the microparticle surface curvature. The optimal experimental conditions in the OBD measurement of the single microparticle were also obtained using theoretical analysis.

  13. Beam Wave Considerations for Optical Link Budget Calculations

    NASA Technical Reports Server (NTRS)

    Manning, Robert M.

    2016-01-01

    The bounded beam wave nature of electromagnetic radiation emanating from a finite size aperture is considered for diffraction-based link power budget calculations for an optical communications system. Unlike at radio frequency wavelengths, diffraction effects are very important at optical wavelengths. In the general case, the situation cannot be modeled by supposing isotropic radiating antennas and employing the concept of effective isotropic radiated power. It is shown here, however, that these considerations are no more difficult to treat than spherical-wave isotopic based calculations. From first principles, a general expression governing the power transfer for a collimated beam wave is derived and from this are defined the three regions of near-field, first Fresnel zone, and far-field behavior. Corresponding equations for the power transfer are given for each region. It is shown that although the well-known linear expressions for power transfer in the far-field hold for all distances between source and receiver in the radio frequency case, nonlinear behavior within the first Fresnel zone must be accounted for in the optical case at 1550 nm with typical aperture sizes at source/receiver separations less that 100 km.

  14. 1-D ELECTRO-OPTIC BEAM STEERING DEVICE.

    PubMed

    Wang, Wei-Chih; Tsui, Chi Leung

    2011-06-05

    In this paper, we present the design and fabrication of a 1D beam steering device based on planar electro-optic thermal-plastic prisms and a collimator lens array. With the elimination of moving parts, the proposed device is able to overcome the mechanical limitations of present scanning devices, such as fatigue and low operating frequency, while maintaining a small system footprint (~0.5mm×0.5mm). From experimental data, our prototype device is able to achieve a maximum deflection angle of 5.6° for a single stage prism design and 29.2° for a cascaded three prisms stage design. The lens array shows a 4µm collimated beam diameter.

  15. Beam Optics Analysis - An Advanced 3D Trajectory Code

    SciTech Connect

    Ives, R. Lawrence; Bui, Thuc; Vogler, William; Neilson, Jeff; Read, Mike; Shephard, Mark; Bauer, Andrew; Datta, Dibyendu; Beal, Mark

    2006-01-03

    Calabazas Creek Research, Inc. has completed initial development of an advanced, 3D program for modeling electron trajectories in electromagnetic fields. The code is being used to design complex guns and collectors. Beam Optics Analysis (BOA) is a fully relativistic, charged particle code using adaptive, finite element meshing. Geometrical input is imported from CAD programs generating ACIS-formatted files. Parametric data is inputted using an intuitive, graphical user interface (GUI), which also provides control of convergence, accuracy, and post processing. The program includes a magnetic field solver, and magnetic information can be imported from Maxwell 2D/3D and other programs. The program supports thermionic emission and injected beams. Secondary electron emission is also supported, including multiple generations. Work on field emission is in progress as well as implementation of computer optimization of both the geometry and operating parameters. The principle features of the program and its capabilities are presented.

  16. Optical Hash function based on two-beam interference.

    PubMed

    Lai, Hongji; He, Wenqi; Peng, Xiang

    2013-09-01

    An approach for constructing an optical Hash function, also known as a one-way cryptosystem, based on two-beam interference (OHF-TBI) is proposed. The purpose of this method is creating the "digital fingerprint" of any precoding message with arbitrary length. This approach consists of three steps, in which the main step is a one-way processing procedure with a compression mechanism. To achieve the function of one-way property and compressibility, we designed a cascaded process on the basis of the two-beam interference principle and phase-truncation operation. The performance of the mentioned OHF-TBI is verified by theoretical analysis and a set of numerical simulations.

  17. Optical studies of ion-beam synthesized metal alloy nanoparticles

    NASA Astrophysics Data System (ADS)

    Magudapathy, P.; Srivatsava, S. K.; Gangopadhyay, P.; Amirthapandian, S.; Sairam, T. N.; Panigrahi, B. K.

    2015-06-01

    AuxAg1-x alloy nanoparticles with tunable surface plasmon resonance (SPR) have been synthesized on a silica glass substrate. A small Au foil on an Ag foil is irradiated as target substrates such that ion beam falls on both Ag foil and Au foils. Silica slides are kept at an angle ˜45° with respect to the metallic foils. While irradiating the metallic foils with 100 keV Ar+ ions, sputtered Au and Ag atoms get deposited on the silica-glass. In this configuration the foils have been irradiated by Ar+ ions to various fluences at room temperature and the sputtered species are collected on silica slides. Formation of AuxAg1-x nanoparticles has been confirmed from the optical absorption measurements. With respect to the exposure area of Au and Ag foils to the ion beam, the SPR peak position varies from 450 to 500 nm. Green photoluminescence has been observed from these alloy metal nanoparticles.

  18. 1-D ELECTRO-OPTIC BEAM STEERING DEVICE

    PubMed Central

    Wang, Wei-Chih; Tsui, Chi Leung

    2011-01-01

    In this paper, we present the design and fabrication of a 1D beam steering device based on planar electro-optic thermal-plastic prisms and a collimator lens array. With the elimination of moving parts, the proposed device is able to overcome the mechanical limitations of present scanning devices, such as fatigue and low operating frequency, while maintaining a small system footprint (~0.5mm×0.5mm). From experimental data, our prototype device is able to achieve a maximum deflection angle of 5.6° for a single stage prism design and 29.2° for a cascaded three prisms stage design. The lens array shows a 4µm collimated beam diameter. PMID:22199458

  19. Optical beam deflection signal from a single microparticle

    NASA Astrophysics Data System (ADS)

    Wu, Jiaqi; Kitamori, Takehiko; Sawada, Tsuguo

    1990-07-01

    The optical beam deflection (OBD) method was applied to the measurement of a single microparticle, and the signal from one resin microparticle of 200-600 μm in diameter could be detected. Based on the frequency characteristics and size dependence of the OBD signal, this method was found to be more sensitive for a smaller particle, and more effective than the photoacoustic method. Theoretical considerations showed that these characteristics were attributable to the enhancement of the temperature field gradient due to the curvature of the microparticle.

  20. Production and all-optical deceleration of molecular beams

    NASA Astrophysics Data System (ADS)

    Chen, Gary; Jayich, Andrew; Long, Xueping; Ransford, Anthony; Campbell, Wesley

    2015-05-01

    Ultracold molecules open up new opportunities in many areas of study, including many-body physics, quantum chemistry, quantum information, and precision measurements. Current methods cannot easily address the spontaneous decay of molecules into dark states without an amalgam of repump lasers. We present an alternative method to produce cold molecules. A cryogenic buffer gas beam (CBGB) is used to create an intense, slow, cold source of molecules. By using a CBGB for the production, we can quench vibrational modes that cannot be addressed with optical methods. This is then followed by an all-optical scheme using a single ultra-fast laser to decelerate the molecules and a continuous wave laser to cool the species. We have started experiments with strontium monohydride (SrH), but the proposed method should be applicable to a wide range of molecular species.

  1. Texturing Blood-Glucose-Monitoring Optics Using Oxygen Beams

    NASA Technical Reports Server (NTRS)

    Banks, Bruce

    2005-01-01

    A method has been invented for utilizing directed, hyperthermal oxygen atoms and ions for texturing tips of polymeric optical fibers or other polymeric optical components for use in optical measurement of concentration of glucose in blood. The required texture of the sensory surface of such a component amounts to a landscape of microscopic hills having high aspect ratios (hills taller than they are wide), with an average distance between hills of no more than about 5 m. This limit on the average distance between hills is chosen so that blood cells (which are wider) cannot enter the valleys between the hills, where they could obstruct optical sensing of glucose in the blood plasma. On the other hand, the plasma is required to enter the valleys, and a high aspect ratio is intended to maximize the hillside and valley surface area in contact with the plasma, thereby making it possible to obtain a given level of optical glucose- measurement sensitivity with a relatively small volume of blood. The present method of texturing by use of directed, hyperthermal (particle energy >1 eV) oxygen atoms and ions stands in contrast to a prior method of texturing by use of thermal monatomic oxygen characterized by a temperature of the order of 0.5 eV. The prior method yields low-aspect- ratio (approximately hemispherical) craters that are tens of microns wide . too wide to exclude blood cells. The figure schematically depicts parts of a typical apparatus for texturing according to the present method. One or more polymeric optical components to be textured (e.g., multiple optical fibers bundled together for simultaneous processing) are mounted in a vacuum chamber facing a suitable ion- or atom-accelerating device capable of generating a beam of oxygen atoms and/or ions having kinetic energies >1 eV. Typically, such a device includes a heated cathode, in which case it is desirable to interpose a water-cooled thermal-radiation shield to prevent melting of the polymeric component(s) to

  2. Optical trapping of core-shell magnetic microparticles by cylindrical vector beams

    SciTech Connect

    Zhong, Min-Cheng; Gong, Lei; Li, Di; Zhou, Jin-Hua; Wang, Zi-Qiang; Li, Yin-Mei

    2014-11-03

    Optical trapping of core-shell magnetic microparticles is experimentally demonstrated by using cylindrical vector beams. Second, we investigate the optical trapping efficiencies. The results show that radially and azimuthally polarized beams exhibit higher axial trapping efficiencies than the Gaussian beam. Finally, a trapped particle is manipulated to kill a cancer cell. The results make possible utilizing magnetic particles for optical manipulation, which is an important advantage for magnetic particles as labeling agent in targeted medicine and biological analysis.

  3. Non-linear optical measurements using a scanned, Bessel beam

    NASA Astrophysics Data System (ADS)

    Collier, Bradley B.; Awasthi, Samir; Lieu, Deborah K.; Chan, James W.

    2015-03-01

    Oftentimes cells are removed from the body for disease diagnosis or cellular research. This typically requires fluorescent labeling followed by sorting with a flow cytometer; however, possible disruption of cellular function or even cell death due to the presence of the label can occur. This may be acceptable for ex vivo applications, but as cells are more frequently moving from the lab to the body, label-free methods of cell sorting are needed to eliminate these issues. This is especially true of the growing field of stem cell research where specialized cells are needed for treatments. Because differentiation processes are not completely efficient, cells must be sorted to eliminate any unwanted cells (i.e. un-differentiated or differentiated into an unwanted cell type). In order to perform label-free measurements, non-linear optics (NLO) have been increasingly utilized for single cell analysis because of their ability to not disrupt cellular function. An optical system was developed for the measurement of NLO in a microfluidic channel similar to a flow cytometer. In order to improve the excitation efficiency of NLO, a scanned Bessel beam was utilized to create a light-sheet across the channel. The system was tested by monitoring twophoton fluorescence from polystyrene microbeads of different sizes. Fluorescence intensity obtained from light-sheet measurements were significantly greater than measurements made using a static Gaussian beam. In addition, the increase in intensity from larger sized beads was more evident for the light-sheet system.

  4. Compact Simultaneous-beam Optical Strain Measurement System, Phase 5

    NASA Technical Reports Server (NTRS)

    Lant, Christian T.

    1994-01-01

    Recent advances on the laser speckle strain measurement system under development at NASA Lewis Research Center have resulted in a compact, easy-to-use measurement package having many performance improvements over previous systems. NASA has developed this high performance optical strain measurement system for high temperature material testing applications. The system is based on I. Yamaguchi's two-beam speckle-shift strain measurement theory, and uses a new optical design that allows simultaneous recording of laser speckle patterns. This design greatly improves system response over previous implementations of the two-beam speckle-shift technique. The degree of immunity to transient rigid body motions is no longer dependent on the data transfer rate. The system automatically calculates surface strains at a frequency of about 5 Hz using a high speed digital signal processor in a personal computer. This system is fully automated, and can be operated remotely. This report describes the designs and methods used by the system, and shows low temperature strain test results obtained from small diameter tungsten-rhenium and palladium-chrome wires.

  5. Sub-micrometer transverse beam size diagnostics using optical transition radiation

    NASA Astrophysics Data System (ADS)

    Kruchinin, K.; Aryshev, A.; Karataev, P.; Bolzon, B.; Lefevre, T.; Mazzoni, S.; Shevelev, M.; Boogert, S. T.; Nevay, L. J.; Terunuma, N.; Urakawa, J.

    2014-05-01

    Optical transition radiation (OTR) arising when a relativistic charged particle crosses a boundary between two media with different optical properties is widely used as a tool for diagnostics of particle beams in modern accelerator facilities. The resolution of the beam profile monitors based on OTR depends on different effects of the optical system such as spherical and chromatic aberrations and diffraction. In this paper we present a systematic study of the different optical effects influencing the OTR beam profile monitor resolution. Obtained results have shown that such monitors can be used for sub-micrometer beam profile diagnostics. Further improvements and studies of the monitor are discussed.

  6. Beam shaping to provide round and square-shaped beams in optical systems of high-power lasers

    NASA Astrophysics Data System (ADS)

    Laskin, Alexander; Laskin, Vadim

    2016-05-01

    Optical systems of modern high-power lasers require control of irradiance distribution: round or square-shaped flat-top or super-Gaussian irradiance profiles are optimum for amplification in MOPA lasers and for thermal load management while pumping of crystals of solid-state ultra-short pulse lasers to control heat and minimize its impact on the laser power and beam quality while maximizing overall laser efficiency, variable profiles are also important in irradiating of photocathode of Free Electron lasers (FEL). It is suggested to solve the task of irradiance re-distribution using field mapping refractive beam shapers like piShaper. The operational principle of these devices presumes transformation of laser beam intensity from Gaussian to flat-top one with high flatness of output wavefront, saving of beam consistency, providing collimated output beam of low divergence, high transmittance, extended depth of field, negligible residual wave aberration, and achromatic design provides capability to work with ultra-short pulse lasers having broad spectrum. Using the same piShaper device it is possible to realize beams with flat-top, inverse Gauss or super Gauss irradiance distribution by simple variation of input beam diameter, and the beam shape can be round or square with soft edges. This paper will describe some design basics of refractive beam shapers of the field mapping type and optical layouts of their applying in optical systems of high-power lasers. Examples of real implementations and experimental results will be presented as well.

  7. Laser beaming demonstrations at the Starfire Optical Range

    SciTech Connect

    Lipinski, R.J.; Meister, D.C.; Tucker, S.; Leatherman, P.; Fugate, R.Q.; Maes, C.; Lange, W.J.; Cowan, W.

    1995-03-01

    The ability to acquire, track, and accurately direct a laser beam to a satellite is crucial for power-beaming and laser-communications. To assess the state of the art in this area, a team consisting of Air Force Phillips Laboratory, Sandia National Laboratories, and COMSAT Corporation personnel performed some laser beaming demonstrations to various satellites. A ruby laser and a frequency-doubled YAG laser were used with the Phillips Lab Starfire Optical Range (SOR) beam director for this activity. The ruby laser projected 20 J in 6 ms out the telescope with a beam divergence that increased from 1.4 to 4 times the diffraction limit during that time. The doubled YAG projected 0.09 J in 10 ns at 20 Hz. The SOR team demonstrated the ability to move rapidly to a satellite, center it in the telescope, then lock onto it with the tracker, and establish illumination. Several low-earth-orbit satellites with corner-cube retro-reflectors were illuminated at ranges from 1000 to 6000 km with a beam divergence estimated to be about 20 {mu}radians. The return signal from the ruby laser was collected in a 15-cm telescope, detected by a photomultiplier tube, and recorded at 400 kHz. Rapid variations in intensity (as short at 15 {mu}s) were noted, which may be due to speckles caused by phase interference from light reflected from different retro-reflectors on the satellite. The return light from the YAG was collected by a 35-cm telescope and detected by an intensified CCD camera. The satellite brightened by about a factor of 30 in the sunlight when the laser was turned on, and dimmed back to normal when the 50-{mu}radian point-ahead was turned off. The satellite was illuminated at 1 Hz as it entered the earth`s shadow and followed for about 10 seconds in the shadow. In another demonstration, four neighboring GEO satellites were located and centered in succession with a 3.5-m telescope at a rate of about 16 seconds per satellite.

  8. Propagation of a general-type beam through a truncated fractional Fourier transform optical system.

    PubMed

    Zhao, Chengliang; Cai, Yangjian

    2010-03-01

    Paraxial propagation of a general-type beam through a truncated fractional Fourier transform (FRT) optical system is investigated. Analytical formulas for the electric field and effective beam width of a general-type beam in the FRT plane are derived based on the Collins formula. Our formulas can be used to study the propagation of a variety of laser beams--such as Gaussian, cos-Gaussian, cosh-Gaussian, sine-Gaussian, sinh-Gaussian, flat-topped, Hermite-cosh-Gaussian, Hermite-sine-Gaussian, higher-order annular Gaussian, Hermite-sinh-Gaussian and Hermite-cos-Gaussian beams--through a FRT optical system with or without truncation. The propagation properties of a Hermite-cos-Gaussian beam passing through a rectangularly truncated FRT optical system are studied as a numerical example. Our results clearly show that the truncated FRT optical system provides a convenient way for laser beam shaping.

  9. Conversion circularly polarized beam shifting optical vortices with a fractional topological charges in a uniaxial crystal

    NASA Astrophysics Data System (ADS)

    Pogrebnaya, A. O.; Halilov, S. I.; Rubass, A. F.

    2016-08-01

    In this work we have studied the distribution of a circularly polarized beam carrying the optical vortex with fractional topological charge equal to ½ in a uniaxial crystal. We have found that by increasing the angle of inclination of the beam relative to the optical axis of the crystal to α = 1.75 °, mixed dislocation movement observed wave front interference pattern to beam periphery. Experimental research has shown that when the angle α = 2 ° in the central region of the beam, we are seeing the emergence of "fork", optical vortex with a topological charge of the order of 1. The results show depolarization of the beam and the transition to the spin angular momentum of the orbital angular momentum. The intensity of the RCP and LCP component in the beam carrying the optical vortex with fractional topological charge oscillate. The total intensity of the beam as the sum of two orthogonally polarized components does not change.

  10. Generation of highly confined optical bottle beams by exploiting the photonic nanojet effect

    NASA Astrophysics Data System (ADS)

    Kim, Myun-Sik; Scharf, Toralf; Mühlig, Stefan; Rockstuhl, Carsten; Herzig, Hans Peter

    2012-03-01

    We report on the generation of photonic nanojets, which resemble optical bottle beams. They are realized by manipulating the illumination of dielectric microspheres. As illumination we use the outer region of deliberately truncated Bessel-Gauss beam or a focused Gaussian beam with intentionally induced spherical aberrations. For the Bessel-Gauss beam possessing a single side lobe only, the nanojet spot resembles an optical bottle beam with a strong confinement due to the nanojet effect. When multiple side lobes of the aberrated focal spot are used, a chain of 3D optical bottle beams appears. We show the 3D intensity distributions close to the spot and discuss the main characteristics of such optical bottle beams.

  11. Ultrafast Optical Beam Deflection in a Planar Waveguide for High Dynamic Range Recording at Picosecond Resolution

    SciTech Connect

    Sarantos, C H; Heebner, J E

    2008-07-02

    We report the latest performance of an ultrafast, all-optical beam deflector based on a prism array imprinted in a planar waveguide. The deflector enables single-shot, high dynamic range optical recording with picosecond resolution.

  12. Multi-slit triode ion optical system with ballistic beam focusing

    SciTech Connect

    Davydenko, V. Amirov, V.; Gorbovsky, A.; Deichuli, P.; Ivanov, A.; Kolmogorov, A.; Kapitonov, V.; Mishagin, V.; Shikhovtsev, I.; Sorokin, A.; Stupishin, N.; Karpushov, A. N.; Smirnov, A.; Uhlemann, R.

    2016-02-15

    Multi-slit triode ion-optical systems with spherical electrodes are of interest for formation of intense focused neutral beams for plasma heating. At present, two versions of focusing multi-slit triode ion optical system are developed. The first ion optical system forms the proton beam with 15 keV energy, 140 A current, and 30 ms duration. The second ion optical system is intended for heating neutral beam injector of Tokamak Configuration Variable (TCV). The injector produces focused deuterium neutral beam with 35 keV energy, 1 MW power, and 2 s duration. In the later case, the angular beam divergence of the neutral beam is 20-22 mrad in the direction across the slits of the ion optical system and 12 mrad in the direction along the slits.

  13. Two dimensional thermo-optic beam steering using a silicon photonic optical phased array

    NASA Astrophysics Data System (ADS)

    Mahon, Rita; Preussner, Marcel W.; Rabinovich, William S.; Goetz, Peter G.; Kozak, Dmitry A.; Ferraro, Mike S.; Murphy, James L.

    2016-03-01

    Components for free space optical communication terminals such as lasers, amplifiers, and receivers have all seen substantial reduction in both size and power consumption over the past several decades. However, pointing systems, such as fast steering mirrors and gimbals, have remained large, slow and power-hungry. Optical phased arrays provide a possible solution for non-mechanical beam steering devices that can be compact and lower in power. Silicon photonics is a promising technology for phased arrays because it has the potential to scale to many elements and may be compatible with CMOS technology thereby enabling batch fabrication. For most free space optical communication applications, two-dimensional beam steering is needed. To date, silicon photonic phased arrays have achieved two-dimensional steering by combining thermo-optic steering, in-plane, with wavelength tuning by means of an output grating to give angular tuning, out-of-plane. While this architecture might work for certain static communication links, it would be difficult to implement for moving platforms. Other approaches have required N2 controls for an NxN element phased array, which leads to complexity. Hence, in this work we demonstrate steering using the thermo-optic effect for both dimensions with a simplified steering mechanism requiring only two control signals, one for each steering dimension.

  14. Optical fiber tip templating using direct focused ion beam milling.

    PubMed

    Micco, A; Ricciardi, A; Pisco, M; La Ferrara, V; Cusano, A

    2015-11-04

    We report on a method for integrating sub-wavelength resonant structures on top of optical fiber tip. Our fabrication technique is based on direct milling of the glass on the fiber facet by means of focused ion beam. The patterned fiber tip acts as a structured template for successive depositions of any responsive or functional overlay. The proposed method is validated by depositing on the patterned fiber a high refractive index material layer, to obtain a 'double-layer' photonic crystal slab supporting guided resonances, appearing as peaks in the reflection spectrum. Morphological and optical characterizations are performed to investigate the effects of the fabrication process. Our results show how undesired effects, intrinsic to the fabrication procedure should be taken into account in order to guarantee a successful development of the device. Moreover, to demonstrate the flexibility of our approach and the possibility to engineering the resonances, a thin layer of gold is also deposited on the fiber tip, giving rise to a hybrid photonic-plasmonic structure with a complementary spectral response and different optical field distribution at the resonant wavelengths. Overall, this work represents a significant step forward the consolidation of Lab-on-Fiber Technology.

  15. Optical fiber tip templating using direct focused ion beam milling

    PubMed Central

    Micco, A.; Ricciardi, A.; Pisco, M.; La Ferrara, V.; Cusano, A.

    2015-01-01

    We report on a method for integrating sub-wavelength resonant structures on top of optical fiber tip. Our fabrication technique is based on direct milling of the glass on the fiber facet by means of focused ion beam. The patterned fiber tip acts as a structured template for successive depositions of any responsive or functional overlay. The proposed method is validated by depositing on the patterned fiber a high refractive index material layer, to obtain a ‘double-layer’ photonic crystal slab supporting guided resonances, appearing as peaks in the reflection spectrum. Morphological and optical characterizations are performed to investigate the effects of the fabrication process. Our results show how undesired effects, intrinsic to the fabrication procedure should be taken into account in order to guarantee a successful development of the device. Moreover, to demonstrate the flexibility of our approach and the possibility to engineering the resonances, a thin layer of gold is also deposited on the fiber tip, giving rise to a hybrid photonic-plasmonic structure with a complementary spectral response and different optical field distribution at the resonant wavelengths. Overall, this work represents a significant step forward the consolidation of Lab-on-Fiber Technology. PMID:26531887

  16. Monolithically integrated optical displacement sensor based on triangulation and optical beam deflection.

    PubMed

    Higurashi, E; Sawada, R; Ito, T

    1999-03-20

    A monolithically integrated optical displacement sensor based on triangulation and optical beam deflection is reported. This sensor is simple and consists of only a laser diode, a polyimide waveguide, and a split detector (a pair of photodiodes) upon a GaAs substrate. The resultant prototype device is extremely small (750 microm x 800 microm). Experiments have shown that this sensor can measure the displacement of a mirror with resolution of better than 4 nm. Additionally, we have experimentally demonstrated both axial and lateral displacement measurements when we used a cylindrical micromirror (diameter, 125 microm) as a movable external object.

  17. An all-optical velocity filter and beam splitter for generating cold molecular beams: a proposal and simulation

    NASA Astrophysics Data System (ADS)

    Li, Xingjia; Liu, Runqin; Yin, Jianping

    2015-12-01

    In order to generate one or two cold molecular beams that have neither a permanent electric dipole moment nor a magnetic dipole one, a controllable scheme to form an all-optical velocity filter and molecular beam splitter by using two red-detuned, crossing and cavity-enhanced guiding laser beams is proposed, and both the dynamic velocity filtering and beam splitting processes of the guided cold I2 molecular beam are studied by using the three-dimensional Monte Carlo method. Our study shows that by adjusting the laser power difference between the two guiding laser beams from -124 W to 124 W, a splitting ratio of the two-arm output molecular beams from about 10.3% to 89.7% can be obtained. Also, by adjusting the intersection angle between the two standing wave cavities from 80° to 10°, an adjustable splitting ratio from about 1.6% to 98.4% can be obtained. If the intersection angle between the guided oblique beam and the guided straight beam is set to 80°, a cold I2 molecular beam with a full-width at half-maximum longitudinal velocity of 1 m s-1 and a longitudinal temperature of 8 mK can be generated by using an all-optical velocity filter.

  18. Nonparaxial propagation of Lorentz-Gauss beams in uniaxial crystal orthogonal to the optical axis.

    PubMed

    Wang, Xun; Liu, Zhirong; Zhao, Daomu

    2014-04-01

    Analytical expressions for the three components of nonparaxial propagation of a polarized Lorentz-Gauss beam in uniaxial crystal orthogonal to the optical axis are derived and used to investigate its propagation properties in uniaxial crystal. The influences of the initial beam parameters and the parameters of the uniaxial crystal on the evolution of the beam-intensity distribution in the uniaxial crystal are examined in detail. Results show that the statistical properties of a nonparaxial Lorentz-Gauss beam in a uniaxial crystal orthogonal to the optical axis are closely determined by the initial beam's parameters and the parameters of the crystal: the beam waist sizes-w(0), w(0x), and w(0y)-not only affect the size and shape of the beam profile in uniaxial crystal but also determine the nonparaxial effect of a Lorentz-Gauss beam; the beam profile of a Lorentz-Gauss beam in uniaxial crystal is elongated in the x or y direction, which is determined by the ratio of the extraordinary refractive index to the ordinary refractive index; with increasing deviation of the ratio from unity, the extension of the beam profile augments. The results indicate that uniaxial crystal provides an effective and convenient method for modulating the Lorentz-Gauss beams. Our results may be valuable in some fields, such as optical trapping and nonlinear optics, where a light beam with a special profile and polarization is required.

  19. Dual axis translation apparatus and system for translating an optical beam and related method

    DOEpatents

    Cassidy, Kelly

    1991-01-01

    A dual axis translation device and system in accordance with this invention, for translating an optical beam along both an x-axis and a y-axis which are perpendicular to one another, has a beam directing means acting on said optical beam for directing the beam along a particular path transverse to said x and y axes. An arrangement supporting said beam directing means for movement in the x and y direction within a given plane is provided. The arrangement includes a first means for translating said beam directing means along the x-axis in said given plane in order to translate the beam along said x-axis. The arrangement comprises a second means for translating said beam directing means along the y-axis in said given plane in order to translate the beam along said y-axis.

  20. Differential Polarization Nonlinear Optical Microscopy with Adaptive Optics Controlled Multiplexed Beams

    PubMed Central

    Samim, Masood; Sandkuijl, Daaf; Tretyakov, Ian; Cisek, Richard; Barzda, Virginijus

    2013-01-01

    Differential polarization nonlinear optical microscopy has the potential to become an indispensable tool for structural investigations of ordered biological assemblies and microcrystalline aggregates. Their microscopic organization can be probed through fast and sensitive measurements of nonlinear optical signal anisotropy, which can be achieved with microscopic spatial resolution by using time-multiplexed pulsed laser beams with perpendicular polarization orientations and photon-counting detection electronics for signal demultiplexing. In addition, deformable membrane mirrors can be used to correct for optical aberrations in the microscope and simultaneously optimize beam overlap using a genetic algorithm. The beam overlap can be achieved with better accuracy than diffraction limited point-spread function, which allows to perform polarization-resolved measurements on the pixel-by-pixel basis. We describe a newly developed differential polarization microscope and present applications of the differential microscopy technique for structural studies of collagen and cellulose. Both, second harmonic generation, and fluorescence-detected nonlinear absorption anisotropy are used in these investigations. It is shown that the orientation and structural properties of the fibers in biological tissue can be deduced and that the orientation of fluorescent molecules (Congo Red), which label the fibers, can be determined. Differential polarization microscopy sidesteps common issues such as photobleaching and sample movement. Due to tens of megahertz alternating polarization of excitation pulses fast data acquisition can be conveniently applied to measure changes in the nonlinear signal anisotropy in dynamically changing in vivo structures. PMID:24022688

  1. Transformation of optical-vortex beams by holograms with embedded phase singularity

    NASA Astrophysics Data System (ADS)

    Bekshaev, A. Ya.; Orlinska, O. V.

    2010-04-01

    Spatial characteristics of diffracted beams produced by the "fork" holograms from incident circular Laguerre-Gaussian modes are studied theoretically. The complex amplitude distribution of a diffracted beam is described by models of the Kummer beam or of the hypergeometric-Gaussian beam. Physically, in most cases its structure is formed under the influence of the divergent spherical wave originating from the discontinuity caused by the hologram's groove bifurcation. Presence of this wave is manifested by the ripple structure in the near-field beam pattern and by the power-law amplitude decay at the beam periphery. Conditions when the divergent wave is not excited are discussed. The diffracted beam carries a screw wavefront dislocation (optical vortex) whose order equals to algebraic sum of the incident beam azimuthal index and the topological charge of the singularity imparted by the hologram. The input beam singularity can be healed when the above sum is zero. In such cases the diffracted beam can provide better energy concentration in the central intensity peak than the Gaussian beam whose initial distribution coincides with the Gaussian envelope of the incident beam. Applications are possible for generation of optical-vortex beams with prescribed properties and for analyzing the optical-vortex beams in problems of information processing.

  2. Iron free permanent magnet systems for charged particle beam optics

    SciTech Connect

    Lund, S.M.; Halbach, K.

    1995-09-03

    The strength and astounding simplicity of certain permanent magnet materials allow a wide variety of simple, compact configurations of high field strength and quality multipole magnets. Here we analyze the important class of iron-free permanent magnet systems for charged particle beam optics. The theory of conventional segmented multipole magnets formed from uniformly magnetized block magnets placed in regular arrays about a circular magnet aperture is reviewed. Practical multipole configurations resulting are presented that are capable of high and intermediate aperture field strengths. A new class of elliptical aperture magnets is presented within a model with continuously varying magnetization angle. Segmented versions of these magnets promise practical high field dipole and quadrupole magnets with an increased range of applicability.

  3. Electrically Switched Holographic Film for High Speed Optical Beam Steering

    NASA Astrophysics Data System (ADS)

    Sutherland, R. L.; Natarajan, L. V.; Tondiglia, V. P.; Bunning, T. J.

    1997-03-01

    We have developed a novel composite material which forms electrically switchable gratings upon standard holographic recording. The gratings consist of periodic arrays of nanometer scale liquid crystal domains in a dense polymer host. NMR and SEM studies indicate a homeotropic alignment of the liquid crystal with an axial defect or symmetry axis along the long axis of prolate sheroid droplets. Samples exhibit good optical quality with high diffraction efficiency in a single Bragg mode. The diffraction efficiency can be modulated by an external electric field, and wide on/off dynamic range switching (>25 dB) is achieved. Simple models relate the dynamic range, switching voltage (<5 V/μm), and response time (25 μs) to the material morphology. Applications incorporating high speed beam steering will be discussed.

  4. Generation of Laguerre Gaussian beams using spiral phase diffractive elements fabricated on optical fiber tips using focused ion beam milling

    NASA Astrophysics Data System (ADS)

    Rodrigues Ribeiro, R. S.; Dahal, P.; Guerreiro, A.; Jorge, P. A. S.; Viegas, J.

    2016-03-01

    In this work, spiral phase lenses fabricated on the tip of single mode optical fibers are reported. This allows tailoring the fundamental guided mode, a Gaussian beam, into a Laguerre - Gaussian profile without using additional optical elements. The lenses are fabricated using Focused Ion Beam milling, enabling high resolution in the manufacturing process. The phase profiles are evaluated and validated using an implementation of the Finite Differences Time Domain. The output optical intensity profiles matching the numerical simulations are presented and analyzed. Finally, results on cell trapping and manipulation are briefly described.

  5. Optical studies of ion-beam synthesized metal alloy nanoparticles

    SciTech Connect

    Magudapathy, P. Srivatsava, S. K.; Gangopadhyay, P.; Amirthapandian, S.; Sairam, T. N.; Panigrahi, B. K.

    2015-06-24

    Au{sub x}Ag{sub 1-x} alloy nanoparticles with tunable surface plasmon resonance (SPR) have been synthesized on a silica glass substrate. A small Au foil on an Ag foil is irradiated as target substrates such that ion beam falls on both Ag foil and Au foils. Silica slides are kept at an angle ∼45° with respect to the metallic foils. While irradiating the metallic foils with 100 keV Ar{sup +} ions, sputtered Au and Ag atoms get deposited on the silica-glass. In this configuration the foils have been irradiated by Ar{sup +} ions to various fluences at room temperature and the sputtered species are collected on silica slides. Formation of Au{sub x}Ag{sub 1-x} nanoparticles has been confirmed from the optical absorption measurements. With respect to the exposure area of Au and Ag foils to the ion beam, the SPR peak position varies from 450 to 500 nm. Green photoluminescence has been observed from these alloy metal nanoparticles.

  6. Novel adaptive fiber-optics collimator for coherent beam combination.

    PubMed

    Zhi, Dong; Ma, Pengfei; Ma, Yanxing; Wang, Xiaolin; Zhou, Pu; Si, Lei

    2014-12-15

    In this manuscript, we experimentally validate a novel design of adaptive fiber-optics collimator (AFOC), which utilizes two levers to enlarge the movable range of the fiber end cap. The enlargement of the range makes the new AFOC possible to compensate the end-cap/tilt aberration in fiber laser beam combining system. The new AFOC based on flexible hinges and levers was fabricated and the performance of the new AFOC was tested carefully, including its control range, frequency response and control accuracy. Coherent beam combination (CBC) of two 5-W fiber amplifiers array with simultaneously end-cap/tilt control and phase-locking control was implemented successfully with the novel AFOC. Experimental results show that the average normalized power in the bucket (PIB) value increases from 0.311 to 0.934 with active phasing and tilt aberration compensation simultaneously, and with both controls on, the fringe contrast improves to more than 82% from 0% for the case with both control off. This work presents a promising structure for tilt aberration control in high power CBC system.

  7. Implementation of ordinary and extraordinary beams interference by application of diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Khonina, S. N.; Karpeev, S. V.; Morozov, A. A.; Paranin, V. D.

    2016-07-01

    We apply diffractive optical elements in problems of transformation of Bessel beams in a birefringent crystal. Using plane waves expansion we show a significant interference between the ordinary and extraordinary beams due to the energy transfer in the orthogonal transverse components in the nonparaxial mode. A comparative analysis of the merits and lack of diffractive and refractive axicons in problems of formation non-paraxial Bessel beams has shown the preferability of diffractive optics application in crystal optics. The transformation of uniformly polarised Bessel beams in the crystal of Iceland spar in the nonparaxial mode by application of a diffractive axicon is investigated numerically and experimentally.

  8. Instantaneous electron beam emittance measurement system based on the optical transition radiation principle

    NASA Astrophysics Data System (ADS)

    Jiang, Xiao-Guo; Wang, Yuan; Zhang, Kai-Zhi; Yang, Guo-Jun; Shi, Jin-Shui; Deng, Jian-Jun; Li, Jin

    2014-01-01

    One kind of instantaneous electron beam emittance measurement system based on the optical transition radiation principle and double imaging optical method has been set up. It is mainly adopted in the test for the intense electron-beam produced by a linear induction accelerator. The system features two characteristics. The first one concerns the system synchronization signal triggered by the following edge of the main output waveform from a Blumlein switch. The synchronous precision of about 1 ns between the electron beam and the image capture time can be reached in this way so that the electron beam emittance at the desired time point can be obtained. The other advantage of the system is the ability to obtain the beam spot and beam divergence in one measurement so that the calculated result is the true beam emittance at that time, which can explain the electron beam condition. It provides to be a powerful beam diagnostic method for a 2.5 kA, 18.5 MeV, 90 ns (FWHM) electron beam pulse produced by Dragon I. The ability of the instantaneous measurement is about 3 ns and it can measure the beam emittance at any time point during one beam pulse. A series of beam emittances have been obtained for Dragon I. The typical beam spot is 9.0 mm (FWHM) in diameter and the corresponding beam divergence is about 10.5 mrad.

  9. Prevention of electron beam transmittance for biological cell imaging using electron beam excitation-assisted optical microscope

    NASA Astrophysics Data System (ADS)

    Fukuta, Masahiro; Nawa, Yasunori; Inami, Wataru; Kawata, Yoshimasa

    2016-12-01

    We demonstrated the high-spatial-resolution imaging of label-free biological cells using an electron beam excitation-assisted optical (EXA) microscope without irradiation damage by the electron beam. An EXA microscope can be used to observe a specimen with a nanometric light source excited in the Si3N4 membrane by an electron beam. The incident electron beam penetrates the Si3N4 membrane and damages the specimen. To suppress the irradiation damage of the specimen, we prevented the transmittance of the electron beam by coating the Si3N4 membrane with a gold thin film. To obtain an electron beam transmittance through the Si3N4 of 0%, a gold film of 15 nm thickness was required. By adding the gold layer, a label-free cellular structure was observed with 135-nm spatial resolution.

  10. Phase-space analysis of charged and optical beam transport: Wigner rotation angle

    NASA Technical Reports Server (NTRS)

    Dattoli, G.; Torre, Amalia

    1994-01-01

    The possibility of using the phase space formalism to establish a correspondence between the dynamical behavior of squeezed states and optical or charged beams, propagating through linear systems, has received a great deal of attention during the last years. In this connection, it has been indicated how optical experiments may be conceived to measure the Wigner rotation angle. In this paper we address the topic within the context of the paraxial propagation of optical or charged beams and suggest a possible experiment for measuring the Wigner angle using an electron beam passing through quadrupoles and drift sections. The analogous optical system is also discussed.

  11. Optical Mixing Controlled Stimulated Scattering Instabilities Using Blue-Green Interaction Beams

    NASA Astrophysics Data System (ADS)

    Mardirian, M.; Afeyan, B.; Won, K.; Montgomery, D.; Hammer, J.; Kirkwood, R.; Schmitt, A.

    2003-10-01

    The optical mixing of blue and green laser beams in an underdense exploding foil plasma where a resonant EPW can be resonantly generated was examined experimentally on the Omega laser facility at LLE. The effect of this optical mixing generated large amplitude EPW on the SRS backscattering of a separate blue interaction/witness beam was measured. The backscattering and transmission of the Green beam, the backscattering of the witness beam and the transmission of the crossing blue beam were studied as a function of different beam energies to see how to optimize the disruption of the witness beam's backscattering levels by the introduction of controlled levels of fluctuations and incoherence into the plasma. Results will be compared to numerical simulations and previous PRI experiments where large levels of IAW turbulence was generated by using same color crossing laser beams.

  12. Novel theory for propagation of tilted Gaussian beam through aligned optical system

    NASA Astrophysics Data System (ADS)

    Xia, Lei; Gao, Yunguo; Han, Xudong

    2017-03-01

    A novel theory for tilted beam propagation is established in this paper. By setting the propagation direction of the tilted beam as the new optical axis, we establish a virtual optical system that is aligned with the new optical axis. Within the first order approximation of the tilt and off-axis, the propagation of the tilted beam is studied in the virtual system instead of the actual system. To achieve more accurate optical field distributions of tilted Gaussian beams, a complete diffraction integral for a misaligned optical system is derived by using the matrix theory with angular momentums. The theory demonstrates that a tilted TEM00 Gaussian beam passing through an aligned optical element transforms into a decentered Gaussian beam along the propagation direction. The deviations between the peak intensity axis of the decentered Gaussian beam and the new optical axis have linear relationships with the misalignments in the virtual system. ZEMAX simulation of a tilted beam through a thick lens exposed to air shows that the errors between the simulation results and theoretical calculations of the position deviations are less than 2‰ when the misalignments εx, εy, εx', εy' are in the range of [-0.5, 0.5] mm and [-0.5, 0.5]°.

  13. Ghost reflections of Gaussian beams in anamorphic optical systems with an application to Michelson interferometer.

    PubMed

    Abd El-Maksoud, Rania H

    2016-02-20

    In this paper, a methodology is developed to model and analyze the effect of undesired (ghost) reflections of Gaussian beams that are produced by anamorphic optical systems. The superposition of these beams with the nominal beam modulates the nominal power distribution at the recording plane. This modulation may cause contrast reduction, veiling parts of the nominal image, and/or the formation of spurious interference fringes. The developed methodology is based on synthesizing the beam optical paths into nominal and ghost optical beam paths. Similar to the nominal beam, we present the concept that each ghost beam is characterized by a beam size, wavefront radius of curvature, and Gouy phase in the paraxial regime. The nominal and ghost beams are sequentially traced through the system and formulas for estimating the electric field magnitude and phase of each ghost beam at the recording plane are presented. The effective electric field is the addition of the individual nominal and ghost electric fields. Formulas for estimating Gouy phase, the shape of the interference fringes, and the central interference order are introduced. As an application, the theory of the formation of the interference fringes by Michelson interferometer is presented. This theory takes into consideration the ghost reflections that are formed by the beam splitter. To illustrate the theory and to show its wide applicability, simulation examples that include a Mangin mirror, a Michelson interferometer, and a black box optical system are provided.

  14. Beam divergence changing mechanism for short-range inter-unmanned aerial vehicle optical communications.

    PubMed

    Heng, Kiang Huat; Zhong, Wen-De; Cheng, Tee Hiang; Liu, Ning; He, Yingjie

    2009-03-10

    The problems associated with using a single fixed beam divergence for short-range inter-unmanned aerial vehicle free-space optical communications are discussed. To overcome the problems, a beam divergence changing mechanism is proposed. Four different methods are then proposed to implement the beam divergence changing mechanism. The performance of these methods is evaluated in terms of transmission distance under adverse weather conditions. The results show that the performance is greatly improved when the beam divergence changing mechanism is used.

  15. Laser beam propagation through turbulence and adaptive optics for beam delivery improvement

    NASA Astrophysics Data System (ADS)

    Nicolas, Stephane

    2015-10-01

    We report results from numerical simulations of laser beam propagation through atmospheric turbulence. In particular, we study the statistical variations of the fractional beam energy hitting inside an optical aperture placed at several kilometer distance. The simulations are performed for different turbulence conditions and engagement ranges, with and without the use of turbulence mitigation. Turbulence mitigation is simulated with phase conjugation. The energy fluctuations are deduced from time sequence realizations. It is shown that turbulence mitigation leads to an increase of the mean energy inside the aperture and decrease of the fluctuations even in strong turbulence conditions and long distance engagement. As an example, the results are applied to a high energy laser countermeasure system, where we determine the probability that a single laser pulse, or one of the pulses in a sequence, will provide a lethal energy inside the target aperture. Again, turbulence mitigation contributes to increase the performance of the system at long-distance and for strong turbulence conditions in terms of kill probability. We also discuss a specific case where turbulence contributes to increase the pulse energy within the target aperture. The present analysis can be used to evaluate the performance of a variety of systems, such as directed countermeasures, laser communication, and laser weapons.

  16. Scattering of a Tightly Focused Beam by an Optically Trapped Particle

    NASA Technical Reports Server (NTRS)

    Lock, James A.; Wrbanek, Susan Y.; Weiland, Kenneth E.

    2006-01-01

    Near-forward scattering of an optically trapped 5 m radius polystyrene latex sphere by the trapping beam was examined both theoretically and experimentally. Since the trapping beam is tightly focused, the beam fields superpose and interfere with the scattered fields in the forward hemisphere. The observed light intensity consists of a series of concentric bright and dark fringes centered about the forward scattering direction. Both the number of fringes and their contrast depend on the position of the trapping beam focal waist with respect to the sphere. The fringes are caused by diffraction due to the truncation of the tail of the trapping beam as the beam is transmitted through the sphere.

  17. Spatial routing of optical beams through time-domain spatial-spectral filtering

    NASA Astrophysics Data System (ADS)

    Babbitt, W. R.; Mossberg, T. W.

    1995-04-01

    We propose a novel new method of temporal-waveform-controlled high-speed passive spatial routing of optical beams. The method provides for the redirection of optical signals contained within a single input beam into output directions that are specified entirely by temporal information encoded on the waveform of each incident signal. The routing is effected by means of deflection from spectrally structured spatial gratings that may be optically programmed into materials with or without intrinsic frequency selectivity.

  18. Field and imaging properties of two orthogonally polarized Gaussian optical beams with a nonlinear parabolic graded-index rod lens

    NASA Astrophysics Data System (ADS)

    Li, Yucui

    1996-04-01

    The field and imaging formulas of two orthogonally polarized Gaussian light beams through a nonlinear parabolic graded-index rod lens are derived by use of a variational approach and the ABCD law of Gaussian beam propagation. The effects of power and position of one optical beam on the field and propagation and imaging properties of the other optical beam are analyzed.

  19. Optical Gaussian beam interaction with one-dimensional thermal wave in the Raman-Nath configuration.

    PubMed

    Bukowski, Roman J

    2009-03-01

    Optical Gaussian beam interaction with a one-dimensional temperature field in the form of a thermal wave in the Raman-Nath configuration is analyzed. For the description of the Gaussian beam propagation through the nonstationary temperature field the complex geometric optics method was used. The influence of the refractive coefficient modulation by thermal wave on the complex ray phase, path, and amplitude was taken into account. It was assumed that for detection of the modulated Gaussian beam parameters two types of detector can be used: quadrant photodiodes or centroidal photodiodes. The influence of such parameters as the size and position of the Gaussian beam waist, the laser-screen (detector) distance, the thermal wave beam position and width, as well as thermal wave frequency and the distance between the probing optical beam axis and source of thermal waves on the so-called normal signal was taken into account.

  20. Beam studies at the SPEAR3 synchrotron using a digital optical mask

    SciTech Connect

    Zhang, H. D.; Fiorito, R. B.; Corbett, J.; Shkvarunets, A. G.; Tian, K.; Fisher, A.

    2016-05-01

    The 3GeV SPEAR3 synchrotron light source operates in top-up injection mode with up to 500 mA circulating in the storage ring (equivalently 392 nC). Each injection pulse contains 40–80 pC producing a contrast ratio between total stored charge and injected charge of about 6500:1. In order to study transient injected beam dynamics during user operations, it is desirable to optically image the injected pulse in the presence of the bright stored beam. In the present work this is done by imaging the visible component of the synchrotron radiation onto a digital micro-mirror-array device (DMD), which is then used as an optical mask to block out light from the bright central core of the stored beam. The physical masking, together with an asynchronously-gated, ICCD imaging camera, makes it possible to observe the weak injected beam component on a turn-by-turn basis. The DMD optical masking system works similar to a classical solar coronagraph but has some distinct practical advantages: i.e. rapid adaption to changes in the shape of the stored beam, a high extinction ratio for unwanted light and minimum scattering from the primary beam into the secondary optics. In this paper we describe the DMD masking method, features of the high dynamic range point spread function for the SPEAR3 optical beam line and measurements of the injected beam in the presence of the stored beam.

  1. Beam studies at the SPEAR3 synchrotron using a digital optical mask

    NASA Astrophysics Data System (ADS)

    Zhang, H. D.; Fiorito, R. B.; Corbett, J.; Shkvarunets, A. G.; Tian, K.; Fisher, A.

    2016-05-01

    The 3GeV SPEAR3 synchrotron light source operates in top-up injection mode with up to 500 mA circulating in the storage ring (equivalently 392 nC). Each injection pulse contains 40-80 pC producing a contrast ratio between total stored charge and injected charge of about 6500:1. In order to study transient injected beam dynamics during user operations, it is desirable to optically image the injected pulse in the presence of the bright stored beam. In the present work this is done by imaging the visible component of the synchrotron radiation onto a digital micro-mirror-array device (DMD), which is then used as an optical mask to block out light from the bright central core of the stored beam. The physical masking, together with an asynchronously-gated, ICCD imaging camera, makes it possible to observe the weak injected beam component on a turn-by-turn basis. The DMD optical masking system works similar to a classical solar coronagraph but has some distinct practical advantages: i.e. rapid adaption to changes in the shape of the stored beam, a high extinction ratio for unwanted light and minimum scattering from the primary beam into the secondary optics. In this paper we describe the DMD masking method, features of the high dynamic range point spread function for the SPEAR3 optical beam line and measurements of the injected beam in the presence of the stored beam.

  2. Fiber Optic Picosecond Laser Pulse Transmission Line for Hydrogen Ion Beam Profile Measurement

    SciTech Connect

    Liu, Yun; Huang, Chunning; Aleksandrov, Alexander V

    2013-01-01

    We present a fiber optic laser pulse transmission line for non-intrusive longitudinal profile measurement of the hydrogen ion (H-) beam at the front-end of the Spallation Neutron Source (SNS) accelerator. The 80.5 MHz, 2.5 ps, multi-killowatt optical pulses are delivered to the accelerator beam line through a large mode area polarization maintaining optical fiber to ensure a high measurement stability. The transmission efficiency, output laser beam quality, pulse jitter and pulse width broadening over a 100-ft fiber line are experimentally investigated. A successful measurement of the H- beam microbunch (~130 ps) profile is obtained. Our experiment is the first demonstration of particle beam profile diagnostics using fiber optic laser pulse transmission line.

  3. Orbital angular momentum of helical necklace beams in colloid-based nonlinear optical metamaterials (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Walasik, Wiktor T.; Silahli, Salih Z.; Litchinitser, Natalia M.

    2016-09-01

    Colloidal metamaterials are a robust and flexible platform for engineering of optical nonlinearities and studies of light filamentation. To date, nonlinear propagation and modulation instability of Gaussian beams and optical vortices carrying orbital angular momentum were studied in such media. Here, we investigate the propagation of necklace beams and the conservation of the orbital angular momentum in colloidal media with saturable nonlinearity. We study various scenarios leading to generation of helical necklace beams or twisted beams, depending on the radius, power, and charge of the input vortex beam. Helical beams are build of two separate solitary beams with circular cross-sections that spiral around their center of mass as a result of the equilibrium between the attraction force of in-phase solitons and the centrifugal force associated with the rotational movement. A twisted beam is a single beam with an elliptical cross-section that rotates around it's own axis. We show that the orbital angular momentum is converted into the rotational motion at different rates for helical and twisted beams. While earlier studies reported that solitary beams are expelled form the initial vortex ring along straight trajectories tangent to the vortex ring, we show that depending on the charge and the power of the initial beam, these trajectories can diverge from the tangential direction and may be curvilinear. These results provide a detailed description of necklace beam dynamics in saturable nonlinear media and may be useful in studies of light filamentation in liquids and light propagation in highly scattering colloids and biological samples.

  4. Focusing optics of a parallel beam CCD optical tomography apparatus for 3D radiation gel dosimetry.

    PubMed

    Krstajić, Nikola; Doran, Simon J

    2006-04-21

    Optical tomography of gel dosimeters is a promising and cost-effective avenue for quality control of radiotherapy treatments such as intensity-modulated radiotherapy (IMRT). Systems based on a laser coupled to a photodiode have so far shown the best results within the context of optical scanning of radiosensitive gels, but are very slow ( approximately 9 min per slice) and poorly suited to measurements that require many slices. Here, we describe a fast, three-dimensional (3D) optical computed tomography (optical-CT) apparatus, based on a broad, collimated beam, obtained from a high power LED and detected by a charged coupled detector (CCD). The main advantages of such a system are (i) an acquisition speed approximately two orders of magnitude higher than a laser-based system when 3D data are required, and (ii) a greater simplicity of design. This paper advances our previous work by introducing a new design of focusing optics, which take information from a suitably positioned focal plane and project an image onto the CCD. An analysis of the ray optics is presented, which explains the roles of telecentricity, focusing, acceptance angle and depth-of-field (DOF) in the formation of projections. A discussion of the approximation involved in measuring the line integrals required for filtered backprojection reconstruction is given. Experimental results demonstrate (i) the effect on projections of changing the position of the focal plane of the apparatus, (ii) how to measure the acceptance angle of the optics, and (iii) the ability of the new scanner to image both absorbing and scattering gel phantoms. The quality of reconstructed images is very promising and suggests that the new apparatus may be useful in a clinical setting for fast and accurate 3D dosimetry.

  5. Influence of laser beam characteristics and focusing optics on optical laser-induced breakdown detection

    NASA Astrophysics Data System (ADS)

    Walther, C.; Hauser, W.

    2009-12-01

    Laser-induced breakdown detection (LIBD) is a well established technique for measuring size and concentration of inorganic colloids in liquids. However, most applications of LIBD are restricted to the measurement of mean sizes, which is problematic in cases of wide colloid size distributions (PSD) as typically is the case in natural systems. Evaluation of PSDs from LIBD is possible but requires detailed control of the power density within the laser focus. In the present work we describe the mathematical treatment how to calculate this power density from the beam characteristics of the light source and the optical properties of the focusing optics. The results are compared to measured spatial distributions of breakdown events of three LIBD setups.

  6. Optical methods for measurements of surface shape in optical components for high power laser beam forming

    NASA Astrophysics Data System (ADS)

    Józwik, Michał; Trusiak, Maciej; LiŻewski, Kamil; Martínez-Carranza, Juan; Voznesenskiy, Nikolay; Kujawińska, Małgorzata

    2016-12-01

    The paper presents modifications of full-field optical methods commonly used to test the surface quality of optical components used for forming a high power laser beam and tests of a final wavefront. The modifications in reference to surface measurements rely on implementation of the novel fringe pattern processing methods including the quality improvement of initial interferogram and analysis of a reconstructed phase based on Hilbert-Huang transform aided by the principal component analysis. Also the Point Diffraction Interferometer as the efficient tool for high quality measurements of elements with high NA is introduced. In reference to a wavefront quality measurements two solutions are discussed: the use of a lateral shear interferometer and the system employing Transport of Intensity Equation method. The pros and cons for both methods are discussed.

  7. Generating optical superimposed vortex beam with tunable orbital angular momentum using integrated devices

    PubMed Central

    Wang, Yu; Feng, Xue; Zhang, Dengke; Zhao, Peng; Li, Xiangdong; Cui, Kaiyu; Liu, Fang; Huang, Yidong

    2015-01-01

    An integrated device, which consists of a variable amplitude splitter and an orbital angular momentum (OAM) emitter, is proposed for the superposition of optical vortex beams. With fixed wavelength and power of incident beam, the OAM of the radiated optical superimposed vortex beam can be dynamically tuned. To verify the operating principle, the proposed device has been fabricated on the SOI substrate and experimentally measured. The experimental results confirm the tunability of superimposed vortex beams. Moreover, the ability of independently varying the OAM flux and the geometric distribution of intensity is illustrated and discussed with numerical simulation. We believe that this work would be promising in various applications. PMID:26190669

  8. SU-E-T-159: Characteristics of Fiber-Optic Radiation Sensor for Proton Therapeutic Beam

    SciTech Connect

    Son, J; Kim, M; Hwang, U; Park, J; Lim, Y; Lee, S; Shin, D; Park, S; Yoon, M

    2015-06-15

    Purpose: A fiber-optic radiation sensor using Cerenkov radiation has been widely studied for use as a dosimeter for proton therapeutic beam. Although the fiber-optic radiation sensor has already been investigated for proton therapeutic, it has been examined relatively little work for clinical therapeutic proton beams. In this study, we evaluated characteristics of a fiber-optic radiation sensor for clinical therapeutic proton beams. We experimentally evaluated dose-rate dependence, dose response and energy dependence for the proton beam. Methods: A fiber-optic radiation sensor was placed in a water phantom. Beams with energies of low, middle and high were used in the passively-scattered proton therapeutic beam at the National Cancer Center in Korea. The sensor consists of two plastic optical fibers (POF). A reference POF and 2 cm longer POF were used to utilize the subtraction method for having sensitive volume. Each POF is optically coupled to the Multi-Anode Photo Multiplier Tube (MAPMT) and the MAPMT signals are processed using National Instruments Data Acquisition System (NI-DAQ). We were investigated dosimetric properties including dose-rate dependence, dose response and energy dependence. Results: We have successfully evaluated characteristics of a fiber optic radiation sensor using Cerenkov radiation. The fiber-optic radiation sensor showed the dose response linearity and low energy dependence. In addition, as the dose-rate was increased, Cerenkov radiation increased linearly. Conclusion: We evaluated the basic characteristics of the fiber optic radiation sensor, the dosimetry tool, to raise the quality of proton therapy. Based on the research, we developed a real time dosimetry system of the optic fiber to confirm the real time beam position and energy for therapeutic proton pencil beam.

  9. Optical Frequency Domain Visualization of Electron Beam Driven Plasma Wakefields

    SciTech Connect

    Zgadzaj, Rafal; Downer, Michael C.; Muggli, Patric; Yakimenko, Vitaly; Kusche, Karl; Fedurin, Michhail; Babzien, Marcus

    2010-11-04

    Bunch driven plasma wakefield accelerators (PWFA), such as the 'plasma afterburner', are a promising emerging method for significantly increasing the energy output of conventional particle accelerators. The study and optimization of this method would benefit from an experimental correlation of the drive bunch parameters and the accelerated particle parameters with the corresponding plasma wave structure. However, the plasma wave structure has not been observed directly so far. We will report ongoing development of a noninvasive optical Frequency Domain Interferometric (FDI) and Holographic (FDH) diagnostics of bunch driven plasma wakes. Both FDI and FDH have been previously demonstrated in the case of laser driven wakes. These techniques employ two laser pulses co-propagating with the drive particle bunch and the trailing plasma wave. One pulse propagates ahead of the drive bunch and serves as a reference, while the second is overlapped with the plasma wave and probes its structure. The multi-shot FDI and single-shot FDH diagnostics permit direct noninvasive observation of longitudinal and transverse structure of the plasma wakes. The experiment is being developed at the 70 MeV Linac in the Accelerator Test Facility at Brookhaven National Laboratory to visualize wakes generated by two and multi-bunch drive beams.

  10. Molecular Beam Optical Zeeman Spectroscopy of Vanadium Monoxide, VO

    NASA Astrophysics Data System (ADS)

    Nguyen, Trung; Zhang, Ruohan; Steimle, Timothy

    2016-06-01

    Like almost all astronomical studies, exoplanet investigations are observational endeavors that rely primarily on remote spectroscopic sensing to infer the physical properties of planets. Most exoplanet related information is inferred from to temporal variation of luminosity of the parent star. An effective method of monitoring this variation is via Magnetic Doppler Imaging (MDI), which uses optical polarimetry of paramagnetic molecules or atoms. One promising paramagnetic stellar absorption is the near infrared spectrum of VO. With this in mind, we have begun a project to record and analyze the field-free and Zeeman spectrum of the band. A cold (approx. 20 K) beam of VO was probed with a single frequency laser and detected using laser induced fluorescence. The determined spectral parameters will be discussed and compared to those extracted from the analysis of a hot spectrum. Supported by the National Science Foundation under the Grant No. CHE-1265885. O. Kochukhov, N. Rusomarov, J. A. Valenti, H. C. Stempels, F. Snik, M. Rodenhuis, N. Piskunov, V. Makaganiuk, C. U. Keller and C. M. Johns-Krull, Astron. Astrophys. 574 (Pt. 2), A79/71-A79/12 (2015). S. V. Berdyugina, Astron. Soc. Pac. Conf. Ser. 437 (Solar Polarization 6), 219-235 (2011). S. V. Berdyugina, P. A. Braun, D. M. Fluri and S. K. Solanki, Astron. Astrophys. 444 (3), 947-960 (2005). A. S. C. Cheung, P. G. Hajigeorgiou, G. Huang, S. Z. Huang and A. J. Merer, J. Mol. Spectrosc. 163 (2), 443-458 (1994)

  11. Optical Frequency Domain Visualization of Electron Beam Driven Plasma Wakefields

    NASA Astrophysics Data System (ADS)

    Zgadzaj, Rafal; Downer, Michael C.; Muggli, Patric; Yakimenko, Vitaly; Kusche, Karl; Fedurin, Michhail; Babzien, Marcus

    2010-11-01

    Bunch driven plasma wakefield accelerators (PWFA), such as the "plasma afterburner," are a promising emerging method for significantly increasing the energy output of conventional particle accelerators [1]. The study and optimization of this method would benefit from an experimental correlation of the drive bunch parameters and the accelerated particle parameters with the corresponding plasma wave structure. However, the plasma wave structure has not been observed directly so far. We will report ongoing development of a noninvasive optical Frequency Domain Interferometric (FDI) [2] and Holographic (FDH) [3] diagnostics of bunch driven plasma wakes. Both FDI and FDH have been previously demonstrated in the case of laser driven wakes. These techniques employ two laser pulses co-propagating with the drive particle bunch and the trailing plasma wave. One pulse propagates ahead of the drive bunch and serves as a reference, while the second is overlapped with the plasma wave and probes its structure. The multi-shot FDI and single-shot FDH diagnostics permit direct noninvasive observation of longitudinal and transverse structure of the plasma wakes. The experiment is being developed at the 70 MeV Linac in the Accelerator Test Facility at Brookhaven National Laboratory to visualize wakes generated by two [4] and multi-bunch [5] drive beams.

  12. Stability analysis of direct-detection cooperative optical beam tracking

    NASA Astrophysics Data System (ADS)

    Marola, Giovanni; Santerini, Daniele; Prati, Giancarlo

    1989-05-01

    The system under consideration is a cooperative spatial tracking system between two stations for laser beam communications, using a quadrant photodetector at each station. After determining the equilibrium points of the cooperative system for the case of periodical relative motion, the authors concentrate on the stability of the transient behavior around the equilibrium points for the case of uniform angular relative motion. This case corresponds to an assumption that the steady-state motion is slow with respect to transient phenomena, and is applicable to currently foreseen intersatellite and deep-space optical communications. The analysis is aimed at determining the combined effect of the basic system parameters, such as propagation delay time, tracking loop gains, DC servomotors time constant, and point-ahead velocity error, on the stability and the transient behavior of the overall tracking system. The stability conditions and the transient response around the steady-state trajectory provide a tool for evaluating the consistency of the design parameters for a given propagation delay.

  13. Acousto-Optic Beam Sampler, Part 2. Green’s Function Solution to Acousto-Optic Interaction Problem.

    DTIC Science & Technology

    This part of the ’ Acousto - Optic Beam Sampler,’ series lays down the formalism behind the Green’s function integral approach to solving the acousto ... optic scattering problem. The advantage of this formulation which is applicable to gases is shown through developing the solution to the scattering

  14. Optical vortex conversion in the elliptic vortex-beam propagating orthogonally to the crystal optical axis: the experiment

    NASA Astrophysics Data System (ADS)

    Sokolenko, Bogdan; Kudryavtseva, Maria; Zinovyev, Alexey; Konovalenko, Victor; Rubass, Alex

    2012-01-01

    We have experimentally analyzed the topological reactions occurred in the elliptic vortex-beam transmitting orthogonally to the optical axis of the SiO2 crystal. We have revealed that the oscillations of the polarization state when propagating the beam are accompanied by reconstruction of the polarization singularities at the beam cross-section that, in turn, entails the reconstruction of the wavefront in each circularly polarized beam component. Both synchronic oscillations of the spin angular momentum and the sign of the vortex topological charge are expressing in a field structure as birth and annihilation of topological dipoles. Also periodical conversion of the vortex ellipticity along the crystal length z and huge splash of spin angular momentum were analysed. The run of the dislocation reactions in the beam component results in converting the sign of the topological charge in the centered optical vortex, the distance of the vortex conversion being about 0.05 of the wavelength.

  15. LogAmp electronics and optical transmission for the new SPS beam position measurement system

    NASA Astrophysics Data System (ADS)

    Bogey, T.; Deplano, C.; Gonzalez, J. L.; Savioz, J. J.

    2013-12-01

    A new front-end board is under development for the CERN SPS Multi ORbit Position System (MOPOS). Based on logarithmic amplifiers, it measures the beam position over a large dynamic range of beam intensities and resolves the multi-batch structure of the SPS beams. Analogue data are digitized at 10 MS/s, packed in frames by an FPGA and on every turn sent to the readout board, via a 2.4 Gb/s optical transmission link. A first prototype has been successfully tested with several SPS beams. This paper presents an overall description of the system and its capabilities highlighted by the first beam measurements.

  16. Beam quality after propagation of Nd:YAG laser light through large-core optical fibers.

    PubMed

    Kuhn, A; Blewett, I J; Hand, D P; Jones, J D

    2000-12-20

    Laser beam characteristics are altered during propagation through large-core optical fibers. The distribution of modes excited by the input laser beam is modified by means of mode coupling on transmission through the fiber, leading to spatial dispersion of the profile and, ultimately and unavoidably, to degradation in the quality of the delivered beam unless the beam is spatially filtered with consequent power loss. Furthermore, a mismatch between the intensity profile of a typical focused high-power laser beam and the profile of the step-index fiber gives rise to additional beam-quality degradation. Modern materials processing applications demand ever higher delivered beam qualities (as measured by a parameter such as M(2)) to achieve greater machining precision and efficiency, a demand that is currently in conflict with the desire to utilize the convenience and flexibility of large-core fiber-optic beam delivery. We present a detailed experimental investigation of the principal beam-quality degradation effects associated with fiber-optic beam delivery and use numerical modeling to aid an initial discussion of the causes of such degradation.

  17. Optical profile determining apparatus and associated methods including the use of a plurality of wavelengths in the reference beam and a plurality of wavelengths in a reflective transit beam

    NASA Technical Reports Server (NTRS)

    Montgomery, Robert M. (Inventor)

    2006-01-01

    An optical profile determining apparatus includes an optical detector and an optical source. The optical source generates a transmit beam including a plurality of wavelengths, and generates a reference beam including the plurality of wavelengths. Optical elements direct the transmit beam to a target, direct a resulting reflected transmit beam back from the target to the optical detector, and combine the reference beam with the reflected transmit beam so that a profile of the target is based upon fringe contrast produced by the plurality of wavelengths in the reference beam and the plurality of wavelengths in the reflected transmit beam.

  18. Acousto-optic liquid-crystal analog beam former for phased-array antennas.

    PubMed

    Riza, N A

    1994-06-10

    A compact phased-array antenna acousto-optic beam former with element-level analog phase (0-2π) and amplitude control using nematic-liquid-crystal display-type technology is experimentally demonstrated. Measurements indicate > 6-bit phase control and 52.6 dB of amplitude-attenuation control. High-quality error calibration and antenna sidelobe-level control is possible with this low-control-power analog beam former. Optical system options using rf Bragg cells or wideband Bragg cells are discussed, with the rf design being the current preferred approach. Transmit-receive beam forming based on frequency upconversion-downconversion by electronic mixing is introduced for the rf Bragg-cell beam former, and comparisons with digital beam forming are highlighted. A millimeter-wave signal generation and control optical architecture is described.

  19. CO[sub 2] laser beam propagation with ZnSe optics

    SciTech Connect

    Leong, K.H.; Liu, Yi; Holdridge, D.J.

    1992-01-01

    Beam propagation characteristics of ZnSe optics used in kiloWatt power CO[sub 2] laser aided material processing applications are determined using the Prometec Laser Beam Analyzer. The laser used was a Rofin Sinar RS6000 CO[sub 2] laser with mode aperturing. Beam power varied from 500W to 6300W and beam modes used were TEM[sub 00], TEM[sub 01], TEM[sub 10] and TEM[sub 20]. Both transmissive and reflective optics were examined. The ZnSe lenses tested included meniscus, diffractive and cylindrical lenses of 5in focal length and a 10in focal length integrading lens. Reflective optics included an integrator and a 5in focal length parabolic mirror for welding. Parameters obtained included beam propagation profiles, intensity profiles, depth of focus, spot size and back focal length. A subset of the data obtained is presented here. Details of the work will appear in a full length paper.

  20. CO{sub 2} laser beam propagation with ZnSe optics

    SciTech Connect

    Leong, K.H.; Liu, Yi; Holdridge, D.J.

    1992-11-01

    Beam propagation characteristics of ZnSe optics used in kiloWatt power CO{sub 2} laser aided material processing applications are determined using the Prometec Laser Beam Analyzer. The laser used was a Rofin Sinar RS6000 CO{sub 2} laser with mode aperturing. Beam power varied from 500W to 6300W and beam modes used were TEM{sub 00}, TEM{sub 01}, TEM{sub 10} and TEM{sub 20}. Both transmissive and reflective optics were examined. The ZnSe lenses tested included meniscus, diffractive and cylindrical lenses of 5in focal length and a 10in focal length integrading lens. Reflective optics included an integrator and a 5in focal length parabolic mirror for welding. Parameters obtained included beam propagation profiles, intensity profiles, depth of focus, spot size and back focal length. A subset of the data obtained is presented here. Details of the work will appear in a full length paper.

  1. Propagation of a random electromagnetic beam through a misaligned optical system in turbulent atmosphere.

    PubMed

    Zhu, Yingbin; Zhao, Daomu

    2008-10-01

    On the basis of the generalized diffraction integral formula for misaligned optical systems in the spatial domain, an analytical propagation expression for the elements of the cross-spectral density matrix of a random electromagnetic beam passing through a misaligned optical system in turbulent atmosphere is derived. Some analyses are illustrated by numerical examples relating to changes in the state of polarization of an electromagnetic Gaussian Schell-model beam propagating through such an optical system. It is shown that the misalignment has a significant influence on the intensity profile and the state of polarization of the beam, but the influence becomes smaller for the beam propagating in strong turbulent atmosphere. The method in this paper can be applied for sources that are either isotropic or anisotropic. It is shown that the isotropic sources and the anisotropic sources have different polarization properties on beam propagation.

  2. Quantum electrodynamics analysis of optical binding in counterpropagating beams and effect of particle size.

    PubMed

    Rodriguez, Justo

    2008-10-01

    A general expression for optical binding energy between particles of any size, in counterpropagating beams with and without interference, is derived using quantum electrodynamics. The effect of particle size on the optically induced interparticle energy surface, which has been the subject of recent research, is explored. Significant changes in this surface when particle size approaches the wavelength of the optical field are revealed. Finally, optically induced particle arrays that may be fabricated with these potentials are briefly discussed.

  3. Optical pulling force on a magneto-dielectric Rayleigh sphere in Bessel tractor polarized beams

    NASA Astrophysics Data System (ADS)

    Mitri, F. G.; Li, R. X.; Yang, R. P.; Guo, L. X.; Ding, C. Y.

    2016-11-01

    The optical radiation force induced by Bessel (vortex) beams on a magneto-dielectric subwavelength sphere is investigated with particular emphasis on the beam polarization and order l (or topological charge). The analysis is focused on identifying the regions and some of the conditions to achieve retrograde motion of the sphere centered on the axis of wave propagation of the incident beam, or shifted off-axially. Exact non-paraxial analytical solutions are established, and computations for linear, circular, radial, azimuthal and mixed polarizations of the individual plane wave components forming the Bessel (vortex) beams by means of the angular spectrum decomposition method (ASDM) illustrate the theory with particular emphasis on the tractor (i.e. reversal) behavior of the force. This effect results in the pulling of the magneto-dielectric sphere against the forward linear momentum density flux associated with the incoming waves. Should some conditions related to the choice of the beam parameters as well as the permittivity and permeability of the sphere be met, the optical force vanishes and reverses sign. Moreover, the beam polarization is shown to affect differently the axial negative pulling force for either the zeroth- or the first-order Bessel beam. When the sphere is centered on the beam‧s axis, the axial force component is always negative for the zeroth-order Bessel beam except for the radial and azimuthal polarization configurations. Nonetheless, for the first-order Bessel beam, the axial force is negative for the radial polarization case only. Additional tractor beam effects arise when the sphere departs from the center of the beam. It is also demonstrated that the tractor beam effect arises from the force component originating from the cross-interaction between the electric and magnetic dipoles. Potential applications are in particle manipulation, optical levitation, tractor beam tweezers, and other emergent technologies using polarized Bessel beams on

  4. Remarks on the differential algebraic approach to particle beam optics by M. Berz

    SciTech Connect

    Garczynski, V.

    1992-12-31

    The underlying mathematical structure of the differential algebraic approach of M. Berz to particle beam optics is isomorphic to the familiar truncated polynomial algebra. Concrete examples of derivations in this algebra, consistent with the truncation operation, are given.

  5. High-speed high-density holographic memory using electro-optic beam steering devices

    NASA Astrophysics Data System (ADS)

    Chao, Tien-Hsin; Zhou, Hanying; Reyes, George F.; Dragoi, Danut; Hanan, Jay

    2002-11-01

    An innovative compact holographic memory system will be presented. This system utilizes a new electro-optic (E-O) beam steering technology to achieve high-speed, high-density holographic data storage.

  6. Experimental demonstration of spatially coherent beam combining using optical parametric amplification.

    PubMed

    Kurita, Takashi; Sueda, Keiichi; Tsubakimoto, Koji; Miyanaga, Noriaki

    2010-07-05

    We experimentally demonstrated coherent beam combining using optical parametric amplification with a nonlinear crystal pumped by random-phased multiple-beam array of the second harmonic of a Nd:YAG laser at 10-Hz repetition rate. In the proof-of-principle experiment, the phase jump between two pump beams was precisely controlled by a motorized actuator. For the demonstration of multiple-beam combining a random phase plate was used to create random-phased beamlets as a pump pulse. Far-field patterns of the pump, the signal, and the idler indicated that the spatially coherent signal beams were obtained on both cases. This approach allows scaling of the intensity of optical parametric chirped pulse amplification up to the exa-watt level while maintaining diffraction-limited beam quality.

  7. The lensing effect of trapped particles in a dual-beam optical trap.

    PubMed

    Grosser, Steffen; Fritsch, Anatol W; Kiessling, Tobias R; Stange, Roland; Käs, Josef A

    2015-02-23

    In dual-beam optical traps, two counterpropagating, divergent laser beams emitted from opposing laser fibers trap and manipulate dielectric particles. We investigate the lensing effect that trapped particles have on the beams. Our approach makes use of the intrinsic coupling of a beam to the opposing fiber after having passed the trapped particle. We present measurements of this coupling signal for PDMS particles, as well as a model for its dependence on size and refractive index of the trapped particle. As a more complex sample, the coupling of inhomogeneous biological cells is measured and discussed. We show that the lensing effect is well captured by the simple ray optics approximation. The measurements reveal intricate details, such as the thermal lens effect of the beam propagation in a dual-beam trap. For a particle of known size, the model further allows to infer its refractive index simply from the coupling signal.

  8. Three-dimensional focus shaping of partially coherent circularly polarized vortex beams using a binary optic

    NASA Astrophysics Data System (ADS)

    Zhang, Zhou; Fan, Hong; Xu, Hua-Feng; Qu, Jun; Huang, Wei

    2015-06-01

    The three-dimensional (3D) focus shaping technique using the combination of partially coherent circularly polarized vortex beams with a binary diffractive optical element (DOE) is reported. It is found that the intensity distribution near the focus can be tailored in three dimensions by appropriately adjusting the parameters of the incident beams, numerical aperture of the objective lens, and the design of the DOE. Numerical results show that partially coherent circularly polarized vortex beams can be used to generate several special beam patterns, such as optical chain, optical needle, optical dark channel, flat-topped field, and 3D optical cage. Furthermore, compared with the ordinary 3D optical cage, this kind of 3D optical cage generated by our method has a controllable switch; that is, it can be easy to ‘open’ and ‘close’ by controlling the coherence length of the incident beams. Our work may find valuable applications in optical tweezers, microscopes, laser processing, and so on.

  9. Numerical study of super-resolved optical microscopy with partly staggered beams

    NASA Astrophysics Data System (ADS)

    He, Jinping; Wang, Nan; Kobayashi, Takayoshi

    2016-12-01

    The resolving power of optical microscopy involving two or even more beams, such as pump-probe microscopy and nonlinear optical microscopy, can be enhanced both laterally and longitudinally with partly staggered beams. A numerical study of the new super-resolution imaging technology is performed with vector diffraction theory. The influence of polarization is discussed. A resolving power of sub-100 nm and sub-300 nm in the lateral and longitudinal directions, respectively, is achievable.

  10. BOA, Beam Optics Analyzer A Particle-In-Cell Code

    SciTech Connect

    Thuc Bui

    2007-12-06

    The program was tasked with implementing time dependent analysis of charges particles into an existing finite element code with adaptive meshing, called Beam Optics Analyzer (BOA). BOA was initially funded by a DOE Phase II program to use the finite element method with adaptive meshing to track particles in unstructured meshes. It uses modern programming techniques, state-of-the-art data structures, so that new methods, features and capabilities are easily added and maintained. This Phase II program was funded to implement plasma simulations in BOA and extend its capabilities to model thermal electrons, secondary emissions, self magnetic field and implement a more comprehensive post-processing and feature-rich GUI. The program was successful in implementing thermal electrons, secondary emissions, and self magnetic field calculations. The BOA GUI was also upgraded significantly, and CCR is receiving interest from the microwave tube and semiconductor equipment industry for the code. Implementation of PIC analysis was partially successful. Computational resource requirements for modeling more than 2000 particles begin to exceed the capability of most readily available computers. Modern plasma analysis typically requires modeling of approximately 2 million particles or more. The problem is that tracking many particles in an unstructured mesh that is adapting becomes inefficient. In particular memory requirements become excessive. This probably makes particle tracking in unstructured meshes currently unfeasible with commonly available computer resources. Consequently, Calabazas Creek Research, Inc. is exploring hybrid codes where the electromagnetic fields are solved on the unstructured, adaptive mesh while particles are tracked on a fixed mesh. Efficient interpolation routines should be able to transfer information between nodes of the two meshes. If successfully developed, this could provide high accuracy and reasonable computational efficiency.

  11. A Novel Approach to the Sensing of Liquid Density Using a Plastic Optical Fibre Cantilever Beam

    ERIC Educational Resources Information Center

    Kulkarni, Atul; Kim, Youngjin; Kim, Taesung

    2009-01-01

    This article reports for the first time the use of a plastic optical fibre (POF) cantilever beam to measure the density of a liquid. The sensor is based on the Archimedes buoyancy principle. The sensor consists of a POF bonded on the surface of a metal beam in the form of a cantilever configuration, and at the free end of the beam a displacer is…

  12. Surface heating by optical beams and application to mid-infrared imaging.

    PubMed

    Haché, Alain; Do, Phuong Anh; Bonora, Stefano

    2012-09-20

    Heating of surfaces by optical beams is investigated theoretically and compared with experimental results in the context of infrared imaging with vanadium dioxide thin films. Using known solutions for the diffusion of point heat sources at the interface between two semi-infinite media, the theory is extended to beams of Gaussian and flat profiles, for steady-state and dynamic regimes. Parameters relevant to imaging, such as spatial resolution and response time, are linked to thermal diffusivity, beam dimensions, and intensity.

  13. Two and Three Beam Pumped Optical Parametric Amplifier of Chirped Pulses

    NASA Astrophysics Data System (ADS)

    Ališauskas, S.; Butkus, R.; Pyragaitė, V.; Smilgevičius, V.; Stabinis, A.; Piskarskas, A.

    2010-04-01

    We present two and three beam pumped optical parametric amplifier of broadband chirped pulses. The seed pulses from Ti:sapphire oscillator were stretched and amplified in a non-collinear geometry pumping with up to three beams derived from independent laser amplifiers. The signal with ˜90 nm bandwidth was amplified up to 0.72 mJ. The conversion efficiency dependence on intersection angles of pump beams is also revealed.

  14. A possibility for using an APPLE undulator to generate a photon beam with transverse optical modes.

    SciTech Connect

    Sasaki, S.; McNulty, I.; Shimada, T.; JAEA

    2008-01-01

    We investigate use of an APPLE-type undulator for generating Laguerre-Gaussian (LG) and Hermite-Gaussian (HG) mode beams. We find that the second harmonic radiation in the circular mode corresponds to an LG beam with l=1, and the second harmonic in the linear mode corresponds to an HG beam with l=1. The combination of an APPLE undulator and conventional monochromator optics may provide an opportunity for a new type of experimental research in the synchrotron radiation community.

  15. Generalized formulas for stochastic electromagnetic beams on inverse propagation through nonsymmetrical optical systems.

    PubMed

    Zhao, Daomu; Zhu, Yingbin

    2009-04-01

    Generalized propagation formulas for the elements of the cross-spectral density matrix of stochastic electromagnetic beams on inverse propagation through an axially symmetrical or nonsymmetrical optical system are derived with the help of Fourier transform and inverse Fourier transform. As an example, we apply the formula to the inverse source problem of stochastic electromagnetic Gaussian Schell-model beams.

  16. Normalization of optical Weber waves and Weber-Gauss beams.

    PubMed

    Rodríguez-Lara, B M

    2010-02-01

    The normalization of energy divergent Weber waves and finite energy Weber-Gauss beams is reported. The well-known Bessel and Mathieu waves are used to derive the integral relations between circular, elliptic, and parabolic waves and to present the Bessel and Mathieu wave decomposition of the Weber waves. The efficiency to approximate a Weber-Gauss beam as a finite superposition of Bessel-Gauss beams is also given.

  17. Bessel beams as virtual tips for near-field optics.

    PubMed

    Grosjean, T; Courjon, D; Van Labeke, D

    2003-06-01

    In the previous NFO meeting, we proposed the use of confined evanescent light beams as 'virtual' or 'immaterial' tips. Unfortunately, this technique was hindered by the need for perfectly radially polarized light beams. In this communication, we propose a simple, stable and cheap method allowing the generation of beams of any polarization and more especially of purely radially polarized light beams. We also demonstrate both theoretically and experimentally that for near-field imaging systems polarization is a limiting factor of resolution and light confinement. Finally, we present the very first experimental results dealing with virtual tips.

  18. Experimental generation of tripartite polarization entangled states of bright optical beams

    NASA Astrophysics Data System (ADS)

    Wu, Liang; Yan, Zhihui; Liu, Yanhong; Deng, Ruijie; Jia, Xiaojun; Xie, Changde; Peng, Kunchi

    2016-04-01

    The multipartite polarization entangled states of bright optical beams directly associating with the spin states of atomic ensembles are one of the essential resources in the future quantum information networks, which can be conveniently utilized to transfer and convert quantum states across a network composed of many atomic nodes. In this letter, we present the experimental demonstration of tripartite polarization entanglement described by Stokes operators of optical field. The tripartite entangled states of light at the frequency resonant with D1 line of Rubidium atoms are transformed into the continuous variable polarization entanglement among three bright optical beams via an optical beam splitter network. The obtained entanglement is confirmed by the extended criterion for polarization entanglement of multipartite quantized optical modes.

  19. Direct core structuring of microstructured optical fibers using focused ion beam milling.

    PubMed

    Warren-Smith, Stephen C; André, Ricardo M; Perrella, Christopher; Dellith, Jan; Bartelt, Hartmut

    2016-01-11

    We demonstrate the use of focused ion beam milling to machine optical structures directly into the core of microstructured optical fibers. The particular fiber used was exposed-core microstructured optical fiber, which allowed direct access to the optically guiding core. Two different designs of Fabry-Perot cavity were fabricated and optically characterized. The first cavity was formed by completely removing a section of the fiber core, while the second cavity consisted of a shallow slot milled into the core, leaving the majority of the core intact. This work highlights the possibility of machining complex optical devices directly onto the core of microstructured optical fibers using focused ion beam milling for applications including environmental, chemical, and biological sensing.

  20. Tuning the optical orbital angular momentum of a focused Gaussian beam in an optical supperlattice under the electro-optic effect

    NASA Astrophysics Data System (ADS)

    Wang, Jie; Shi, Jianhong; Tian, Linghao; Chen, Xianfeng

    2012-04-01

    In this paper, we theoretically propose a new method to generate and tune the optical orbital angular momentum. A focused Gaussian beam passing through an optical superlattice under the electro-optic effect carries orbital angular momentum (OAM). This kind of OAM arises from the curl of the polarization. By adjusting the external electric field, the beam waist radius and the crystal length, we can obtain a dramatic variation of the OAM across the output light transverse section. This invention will find applications in the area of optical manipulation.

  1. Experimental analysis of beam pointing system based on liquid crystal optical phase array

    NASA Astrophysics Data System (ADS)

    Shi, Yubin; Zhang, Jianmin; Zhang, Zhen

    2016-12-01

    In this paper, we propose and demonstrate an elementary non-mechanical beam aiming and steering system with a single liquid crystal optical phase array (LC-OPA) and charge-coupled device (CCD). With the conventional method of beam steering control, the LC-OPA device can realize one dimensional beam steering continuously. An improved beam steering strategy is applied to realize two dimensional beam steering with a single LC-OPA. The whole beam aiming and steering system, including an LC-OPA and a retroreflective target, is controlled by the monitor. We test the feasibility of beam steering strategy both in one dimension and in two dimension at first, then the whole system is build up based on the improved strategy. The experimental results show that the max experimental pointing error is 56 μrad, and the average pointing error of the system is 19 μrad.

  2. Optical guiding in a sheet-beam free-electron laser

    NASA Astrophysics Data System (ADS)

    Fruchtman, Amnon

    1988-04-01

    Electron-beam guiding of the amplified wave in the linear growth regime of a cavityless sheet-beam FEL with a planar wiggler is investigated theoretically. The governing equations and the energy integral are derived; analytical results for beams with uniform and triangular density profiles and low or high values of Moore's (1985) coupling parameter (alpha) are obtained; and numerical results for intermediate values are presented in graphs. For low alpha, diffraction is large and the density profile does not affect gain and wave profile; for high alpha, there is significant optical guiding, the gain with a triangular beam is 2 exp 1/3 times higher than with a uniform beam, and the wave profile of the uniform-density beam remains confined to the beam volume.

  3. Scattering of a Gaussian beam by a large perfectly conducting cylinder with application to optical sensors

    NASA Astrophysics Data System (ADS)

    Gardner, Judd Steven

    1999-10-01

    Optical proximity sensing is often used in industry and the commercial realm to provide a system with information it may use in some decision making process. The applications for optical proximity sensing have changed and expanded over the years, and has presented a continually increased demand for higher accuracy. In order to satisfy this demand, new optical techniques have been established which have provided more precise proximity data than ever before, e.g. Atomic Force Microscopy and Photothermal Detection. To accommodate the increase in sensing precision, the precision of the mathematical models used to predict the behavior of the optical scheme must also increase. The particular interest pursued in this dissertation involves the detection of the change in the position of a beam due to some phenomena, e.g. Photothermal Deflection or Atomic Force Microscopy. The deflection of the beam in these cases may be on the order of microradians, and too small to detect with ordinary means. To remedy this, a reflecting cylinder is strategically positioned to reflect the incident deflected beam and, by the cylinder geometry, the reflected beam from the cylinder shows an increased deflection angle compared to the incident beam. If the optical scheme has been designed successfully, the resulting deflection of the reflected beam will be large enough to be detected by a sensor. In order to predict the optical behavior of an incident deflected beam reflected from a cylinder, three mathematical methods, Geometrical Optics, Physical Optics, and an Exact Formulation rigorously based on Maxwell's equations are employed. From these methods, a Geometrical Optics solution, two Physical Optics solutions, and an Exact solution are obtained and compared to demonstrate the accuracy of these mathematical models to predict the electric field behavior of a beam reflected from a cylinder. In all cases a Gaussian, well focused beam is used. The near, transitional, and far zones are considered

  4. Bessel beams in tunable acoustic gradient index lenses and optical trap assisted nanolithography

    NASA Astrophysics Data System (ADS)

    McLeod, Euan

    2009-12-01

    Bessel beams are laser beams whose shape gives them nondiffracting and self-healing properties. They find use in applications requiring a narrow laser beam with a high depth of field. The first part of this thesis presents the study of a new adaptive optical element capable of generating rapidly tunable Bessel beams: the tunable acoustic gradient index (TAG) lens. This device uses piezoelectrically-generated acoustic waves to modulate a fluid's density and refractive index, leading to electrically controllable lensing behavior. Both modeling and experiment are used to explain the observed multiscale Bessel beams. Because the TAG lens operates at frequencies of hundreds of kilohertz, the effective Bessel beam cone angle continuously varies at timescales on the order of microseconds or smaller-orders of magnitude faster than other existing technologies. In addition, the TAG lens may be driven with a Fourier superposition of multiple frequencies, which could enable the generation of arbitrary patterns. The second part of this thesis presents the application of Bessel beams in a new probe-based direct-write optical nanolithography method called optical trap assisted nanolithography (OTAN). When compared to alternative techniques, OTAN makes probe placement and parallelization easier. The method uses Bessel beam optical tweezers to trap dielectric microspheres in close proximity to a surface. These microspheres are then illuminated with pulses from a second laser beam, whose fluence is enhanced directly below the microsphere by focusing and near-field effects to a level great enough to modify the substrate. This technique is used to produce 100 nm features, which are less than lambda/3, and whose sizes agree well with finite-difference time-domain models of the experiment. A demonstration is given of how the technique can be parallelized by trapping multiple microspheres with multiple beams and exposing all spheres in unison with a single pulsed beam. Finally, modeling

  5. Optically pumped Cs vapor lasers: pump-to-laser beam overlap optimization

    NASA Astrophysics Data System (ADS)

    Auslender, Ilya; Cohen, Tom; Lebiush, Eyal; Barmashenko, Boris D.; Rosenwaks, Salman

    2017-01-01

    We present the results of an experimental study of Ti:Sapphire pumped Cs laser and theoretical modeling of these results, where we focused on the influence of the pump-to-laser beam overlap, a crucial parameter for optimizing the output laser power. The dependence of the output laser power on the incident pump power was found for varying pump beam cross-section widths and for a constant laser beam. Maximum laser power > 370 mW with an optical-to-optical efficiency of 43% and slope efficiency 55% was obtained. Non monotonic dependence of the laser power and threshold power on the pump beam radius (at a given pump power) was observed with a maximum laser power and minimum threshold power achieved at the ratio 0.7 between the optimal pump beam and laser beam radius. A simple optical model of the laser, where Gaussian spatial shapes of the pump and laser intensities in any cross section of the beams were assumed, was compared to the experiments. Good agreement was obtained between the measured and calculated dependence of the laser power on the incident pump power at different pump beam radii and of the laser power, threshold power and optimal temperature on the pump beam radius. The model does not use empirical parameters such as mode overlap efficiency but rather the pump and laser beam spatial shapes as input parameters. This model can be applied to different optically pumped alkali lasers with arbitrary spatial distributions of the pump and laser beam widths.

  6. Miniaturized photogenerated electro-optic axicon lens Gaussian-to-Bessel beam conversion.

    PubMed

    Di Domenico, G; Parravicini, J; Antonacci, G; Silvestri, S; Agranat, A J; DelRe, E

    2017-04-01

    We experimentally demonstrate an electro-optic Gaussian-to-Bessel beam-converter miniaturized down to a 30×30  μm pixel in a potassium-lithium-tantalate-niobate (KLTN) paraelectric crystal. The converter is based on the electro-optic activation of a photoinduced and reconfigurable volume axicon lens achieved using a prewritten photorefractive funnel space-charge distribution. The transmitted light beam has a tunable depth of field that can be more than twice that of a conventional beam with the added feature of being self-healing.

  7. Optical apparatus for conversion of whispering-gallery modes into a free space gaussian like beam

    DOEpatents

    Stallard, Barry W.; Makowski, Michael A.; Byers, Jack A.

    1992-01-01

    An optical converter for efficient conversion of millimeter wavelength whispering-gallery gyrotron output into a linearly polarized, free-space Gaussian-like beam. The converter uses a mode-converting taper and three mirror optics. The first mirror has an azimuthal tilt to eliminate the k.sub..phi. component of the propagation vector of the gyrotron output beam. The second mirror has a twist reflector to linearly polarize the beam. The third mirror has a constant phase surface so the converter output is in phase.

  8. Optical 90-deg hybrid of birefringent crystals for freely propagating laser beams

    NASA Astrophysics Data System (ADS)

    Wan, Lingyu; Zhi, Yanan; Zhou, Yu; Liu, Liren

    2010-12-01

    An optical 90-deg hybrid of birefringent crystals for freely propagating laser beams is presented. It consists principally of a quarter-wave plate, two pairs of birefringent crystal plates, and a polarization analyzer. The splitting and recombination of the signal and local-oscillator beams are achieved through the birefringence of the crystals, and a 90-deg phase shift is introduced between orthogonally polarized beam components by use of a quarter-wave plate. The optical hybrid has a self-compensating light path, and its correct function is demonstrated in a self-heterodyne measurement setup.

  9. Continuous Beam Steering From A Segmented Liquid Crystal Optical Phased Array

    NASA Technical Reports Server (NTRS)

    Pouch, John; Nguyen, Hung; Miranda, Felix; Titus, Charles M.; Bos, Philip J.

    2002-01-01

    Optical communications to and from deep space probes will require beams possessing divergence on the order of a microradian, and must be steered with sub-microradian precision. Segmented liquid crystal spatial phase modulators, a type of optical phased array, are considered for this ultra-high resolution beam steering. It is shown here that in an ideal device of this type, there are ultimately no restrictions on the angular resolution. Computer simulations are used to obtain that result, and to analyze the influence of beam truncation and substrate flatness on the performance of this type of device.

  10. Continuous Beam Steering From a Segmented Liquid Crystal Optical Phased Array

    NASA Technical Reports Server (NTRS)

    Titus, Charles M.; Pouch, John; Nguyen, Hung; Miranda, Felix; Bos, Philip J.

    2002-01-01

    Optical communications to and from deep space probes will require beams possessing divergence on the order of a microradian, and must be steered with sub-microradian precision. Segmented liquid crystal spatial phase modulators, a type of optical phased array, are considered for this ultra-high resolution beam steering. It is shown here that in an ideal device of this type, there are ultimately no restrictions on the angular resolution. Computer simulations are used to obtain that result, and to analyze the influence of beam truncation and substrate flatness on the performance of this type of device.

  11. Investigations on the beam pointing stability of a pulsed optical parametric oscillator.

    PubMed

    Fix, Andreas; Stöckl, Christian

    2013-05-06

    Although the beam pointing stability of optical parametric oscillators and amplifiers is important for various applications few results on this parameter have been published. Here, we investigate the beam pointing stability of an injection-seeded, nanosecond optical parametric oscillator, compare it to its pump laser, and measure correlations between them. Although correlation between both quantities are found, the beam pointing stability of the OPO is significantly better that the one of its pump. Furthermore, the concept of the Allan variance is applied to analyze the temporal components of the pointing stability.

  12. Optical binding of particle pairs in retro-reflected beam geometry

    NASA Astrophysics Data System (ADS)

    Damková, Jana; Chvátal, Lukáš; Brzobohatý, Oto; Zemánek, Pavel

    2016-12-01

    Optical binding of polystyrene microparticle pairs in retro-reflected wide Gaussian beam, called "tractor beam", is studied experimentally and the results are compared with the numerical calculations based on the multiple-particle Mie scattering theory. To investigate the dynamics of optically bound particle pairs in three dimensions we employ holographic video microscopy technique. We show that the particle pair motion is strongly dependent on the relative distances of the particles and the switching between applying pushing and pulling force on particle pairs can be achieved only by changing their configuration even though the "tractor-beam" parameters remain unchanged.

  13. Effects of beam wander on free-space optical communications through turbulent atmosphere

    NASA Astrophysics Data System (ADS)

    Zhao, Zhijun; Liao, Rui

    2010-04-01

    Effects of beam wander on uncoded bit-error-rate (BER) of direct-detection OOK modulated FSO communication systems using collimated and focused Gaussian beams are studied. Channel fading statistics are obtained from large-scale wave optics simulations and compared with the closed-form log-normal and gamma-gamma models. The avalanche photodiode (APD) is chosen for photodetection. The accurate McIntyre-Conradi APD model is adopted for performance evaluation. Results show that large performance gain (more than 15dB) can be achieved with fast-tracked focused beams. The upper bound of higher-order adaptive optics gain beyond tracking gain is also studied.

  14. Diffractive optical elements fabricated for beam shaping of high-power diode lasers

    NASA Astrophysics Data System (ADS)

    Vogt, Helge; Biertümpfel, Ralf; Pawlowski, Edgar

    2008-02-01

    This paper discusses the use of diffractive optical elements (DOEs) and micro-optics fabricated by precise pressing in glass for beam shaping of high-power diode lasers. The DOEs are used to diffract the light into the point of interest and to improve the laser beam quality. We have realized circular, flat-top and multi-beam intensity profiles. The highest measured diffraction efficiency was higher than 95 %. The new established fabrication process has potential for mass production of DOEs. SCHOTT's precision glass molding process guarantees a very constant quality over the complete production chain.

  15. Optics measurement and correction during beam acceleration in the Relativistic Heavy Ion Collider

    SciTech Connect

    Liu, C.; Marusic, A.; Minty, M.

    2014-09-09

    To minimize operational complexities, setup of collisions in high energy circular colliders typically involves acceleration with near constant β-functions followed by application of strong focusing quadrupoles at the interaction points (IPs) for the final beta-squeeze. At the Relativistic Heavy Ion Collider (RHIC) beam acceleration and optics squeeze are performed simultaneously. In the past, beam optics correction at RHIC has taken place at injection and at final energy with some interpolation of corrections into the acceleration cycle. Recent measurements of the beam optics during acceleration and squeeze have evidenced significant beta-beats which if corrected could minimize undesirable emittance dilutions and maximize the spin polarization of polarized proton beams by avoidance of higher-order multipole fields sampled by particles within the bunch. In this report the methodology now operational at RHIC for beam optics corrections during acceleration with simultaneous beta-squeeze will be presented together with measurements which conclusively demonstrate the superior beam control. As a valuable by-product, the corrections have minimized the beta-beat at the profile monitors so reducing the dominant error in and providing more precise measurements of the evolution of the beam emittances during acceleration.

  16. Optical apparatus for conversion of whispering-gallery modes into a free space gaussian like beam

    DOEpatents

    Stallard, B.W.; Makowski, M.A.; Byers, J.A.

    1992-05-19

    An optical converter for efficient conversion of millimeter wavelength whispering-gallery gyrotron output into a linearly polarized, free-space Gaussian-like beam is described. The converter uses a mode-converting taper and three mirror optics. The first mirror has an azimuthal tilt to eliminate the k[sub [phi

  17. Electro-optical deflectors as a method of beam smoothing for Inertial Confinement Fusion

    SciTech Connect

    Rothenberg, J.E.

    1997-01-01

    The electro-optic deflector is analyzed and compared to smoothing by spectral dispersion for efficacy as a beam smoothing method for ICF. It is found that the electro-optic deflector is inherently somewhat less efficient when compared either on the basis of equal peak phase modulation or equal generated bandwidth.

  18. Ion beam and plasma jet based methods in ultra-precision optics manufacturing

    NASA Astrophysics Data System (ADS)

    Arnold, Th.; Boehm, G.; Paetzelt, H.; Pietag, F.

    2015-01-01

    Ion beam and plasma jet based techniques can be used in alternative machining processes for generating and finishing of ultra-precision optical surfaces. Since atomistic mechanisms are responsible for surface material modification, etching, and deposition, very high accuracy on the atomic level can be achieved. Various advanced techniques like pulse-width modulated ion beam figuring, sub-aperture reactive ion beam etching, or ion beam assisted structuring, planarization and smoothing technologies have been investigated aiming at precision on sub-nanometer height scale and lateral scales ranging over the full spatial wavelength range from nanometers to meters. Additionally, different atmospheric reactive plasma jet processes and plasma jet assisted process chains for generating, correction and smoothing of complex shaped optical surfaces like aspheres with large departures to best fit sphere or free forms exhibiting strong gradients have been developed in the last decade. In the paper an overview to the most recent trends of non-conventional ultra-precision optics processing is given and latest results of optics manufacturing are shown. Specific examples are given to demonstrate that form generation (e.g. for laser beam shaping optics) and surface finishing and polishing using atmospheric plasma jet tools are promising applications exhibiting advantages with respect to process efficiency and flexibility. Furthermore, the capabilities of ion beam surface figure correction using a new approach to control the tool function are demonstrated.

  19. Superposition and detection of two helical beams for optical orbital angular momentum communication

    NASA Astrophysics Data System (ADS)

    Liu, Yi-Dong; Gao, Chunqing; Gao, Mingwei; Qi, Xiaoqing; Weber, Horst

    2008-07-01

    A loop-like system with a Dove prism is used to generate a collinear superposition of two helical beams with different azimuthal quantum numbers in this manuscript. After the generation of the helical beams distributed on the circle centered at the optical axis by using a binary amplitude grating, the diffractive field is separated into two polarized ones with the same distribution. Rotated by the Dove prism in the loop-like system in counter directions and combined together, the two fields will generate the collinear superposition of two helical beams in certain direction. The experiment shows consistency with the theoretical analysis. This method has potential applications in optical communication by using orbital angular momentum of laser beams (optical vortices).

  20. Electron-beam lithography for micro and nano-optical applications

    NASA Technical Reports Server (NTRS)

    Wilson, Daniel W.; Muller, Richard E.; Echternach, Pierre M.

    2005-01-01

    Direct-write electron-beam lithography has proven to be a powerful technique for fabricating a variety of micro- and nano-optical devices. Binary E-beam lithography is the workhorse technique for fabricating optical devices that require complicated precision nano-scale features. We describe a bi-layer resist system and virtual-mark height measurement for improving the reliability of fabricating binary patterns. Analog E-beam lithography is a newer technique that has found significant application in the fabrication of diffractive optical elements. We describe our techniques for fabricating analog surface-relief profiles in E-beam resist, including some discussion regarding overcoming the problems of resist heating and charging. We also describe a multiple-field-size exposure scheme for suppression of field-stitch induced ghost diffraction orders produced by blazed diffraction gratings on non-flat substrates.

  1. Development of a synchrotron radiation beam monitor for the Integrable Optics Test Accelerator

    SciTech Connect

    Scarpelli, Andrea

    2016-01-01

    Nonlinear integrable optics applied to beam dynamics may mitigate multi-particle instabilities, but proof of principle experiments have never been carried out. The Integrable Optics Test Accelerator (IOTA) is an electron and proton storage ring currently being built at Fermilab, which addresses tests of nonlinear lattice elements in a real machine in addition to experiments on optical stochastic cooling and on the single-electron wave function. These experiments require an outstanding control over the lattice parameters, achievable with fast and precise beam monitoring systems. This work describes the steps for designing and building a beam monitor for IOTA based on synchrotron radiation, able to measure intensity, position and transverse cross-section beam.

  2. Optical design in beam steering environments with emphasis on laser transmission measurements.

    PubMed

    Kranendonk, Laura A; Sanders, Scott T

    2005-11-01

    Optical sensors applied to practical devices often encounter beam steering: the wander and/or diffusion of laser light. Here we provide a framework for minimizing the sensitivity of transmission-based sensors to beam steering without quantitative prediction of the severity of the beam-steering field. Typical goals are increased transmission and/or minimized fluctuations in transmission; such features can improve optical sensor performance (e.g., improved signal-to-noise ratio, response time, or spectral resolution). In our framework, we introduce a parameter for characterizing beam-steering severity. We then compare two approaches for absorption spectroscopy and show that the preferred approach depends on the total spectral range monitored, the spectral resolution desired, and the severity of the beam steering.

  3. Time-Resolved Emittance Characterization of an Induction Linac Beam using Optical Transition Radiation

    SciTech Connect

    Le Sage, G P

    2002-11-05

    An induction linac is used by Lawrence Livermore National Laboratory to perform radiographic testing at the Flash X-ray Radiography facility. Emittance characterization is important since x-ray spot size impacts the resolution of shadow-graphs. Due to the long pulse length, high current, and beam energy, emittance measurement using Optical Transition Radiation is an attractive alternative for reasons that will be described in the text. The utility of OTR-based emittance measurement has been well demonstrated for both RF and induction linacs. We describe the time-resolved emittance characterization of an induction linac electron beam. We have refined the optical collection system for the induction linac application, and have demonstrated a new technique for probing the divergence of a subset of the beam profile. The experimental apparatus, data reduction, and conclusions will be presented. Additionally, a new scheme for characterizing the correlation between beam divergence and spatial coordinates within the beam profile will be described.

  4. Generation of Bessel Beams at mm- and Sub mm-wavelengths by Binary Optical Elements

    NASA Astrophysics Data System (ADS)

    Yu, Y. Z.; Dou, W. B.

    2008-07-01

    In this paper, binary optical elements (BOE’s) are designed for generating Bessel beams at mm- and sub mm- wavelengths. The design tool is to combine a genetic algorithm (GA) for global optimization with a two-dimension finite-difference time-domain (2-D FDTD) method for rigorous electromagnetic computation. The design process for converting a normally incident Gaussian beam into a Bessel beam is described in detail. Numerical results demonstrate that the designed BOE’s can not only successfully produce arbitrary order Bessel beams, but also have higher diffraction efficiencies when compared with amplitude holograms.

  5. Simulation research on beam steering technology based on optical phased array

    NASA Astrophysics Data System (ADS)

    Tian, Junlin; Pan, Xudong

    2015-02-01

    The principle of beam steering technology based on optical phased array (OPA), which is composed of individual phase-modulating units, is introduced. By use of Fraunhofer diffraction and Fourier transformation, the OPA models are established. The influence of main parameters of OPA on beam steering efficiency, including duty ratio (ratio of effective unit size to total unit size), total unit size, unit number, and steering angle, is simulated and analyzed. It shows that beam steering efficiency of OPA is improved with larger duty ratio, smaller total unit size, and smaller steering angle, while the number of units has a very small impact on beam steering efficiency.

  6. Binary micro optics: An application to beam steering

    SciTech Connect

    Goltsos, W.; Holz, M.

    1989-01-01

    Agile steering of a helium-neon laser beam (lambda = 632.8nm) was demonstrated using a complementary pair of 5-cm-aperture diffractive microlens arrays in the Galilean telescopic geometry. Having as many as 60,000 F/5 microlenses, each with parabolic phase profile and 200 micrometers diameter, results in nearly aberration-free beam steering over 11 deg. field of view for top + or - 100 micrometers lateral displacements of one array relative to the other. Wavefront quality and steering efficiency of the deflected beam has been measured as a function of steering angle and is compared to a simple theoretical model.

  7. Analytic design of a zoom XY-beam expander with freeform optical surfaces.

    PubMed

    Duerr, Fabian; Thienpont, Hugo

    2015-11-16

    Many laser applications require specific irradiance distributions to ensure optimal performance. In addition, some applications can benefit from time-varying distributions. In this work, we present the analytic design of a zoom XY-beam expander based on movable freeform optics that allows to simultaneously vary the magnification in x- and y-direction, respectively. This concept is not new: the new is to design and optimally exploit freeform lenses to achieve such an optical functionality. In comparison with zoom beam expanders that use combinations of rotated cylindrical lenses, a freeform system can be more compact, yet achieving excellent overall optical performance throughout the full zoom range.

  8. Effect of control-beam polarization and power on optical time-domain demultiplexing in a new nonlinear optical loop mirror design

    NASA Astrophysics Data System (ADS)

    Grendár, Drahomír; Pottiez, Olivier; Dado, Milan; Müllerová, Jarmila; Dubovan, Jozef

    2009-05-01

    A new scheme of a control-beam-driven nonlinear optical loop mirror (NOLM) with a birefringent twisted fiber and a symmetrical coupler designed for optical time division demultiplexing (OTDM) is analyzed. The theoretical model of the proposed NOLM scheme considers the evolution of polarization states of data and control beams and the mutual interactions of the data and control beams due to the cross-phase modulation (XPM). Attention is given to the optical switching commanded by the control-beam power and by the manipulation of nonlinear polarization rotation of the data and control beam. The simulations of NOLM transmissions demonstrate that the cross talk between demultiplexed and nondemultiplexed beams as an important parameter for optical switching by the presented NOLM can be significantly reduced. The results show that the device can be of interest for all-optical signal manipulations in optical communication networks.

  9. Distributed beam loss monitor based on the Cherenkov effect in an optical fiber

    NASA Astrophysics Data System (ADS)

    Maltseva, Yu; Emanov, F. A.; Petrenko, A. V.; Prisekin, V. G.

    2015-05-01

    This review discusses a distributed beam loss monitor which is based on the Cherenkov effect in an optical fiber and which has been installed at the VEPP-5 Injection Complex at the Budker Institute of Nuclear Physics. The principle of the device operation consists in detecting the Cherenkov radiation generated in an optical fiber by relativistic charged particles that are produced in an electromagnetic shower when highly relativistic beam particles (electrons or positrons) hit the accelerator vacuum chamber wall. Our experiments used a photomultiplier tube (PMT) to detect the Cherenkov light. Knowing when the PMT signal arrives tells us where the beam loss occurs. Using a 20-m-long optical fiber allowed a detector spatial resolution of 3 m. The way to improve the resolution is to optimize the monitor working conditions and optical fiber and PMT parameters, potentially leading to a resolution of as fine as 0.5 m according to our estimates.

  10. Cerenkov light spectrum in an optical fiber exposed to a photon or electron radiation therapy beam

    SciTech Connect

    Lambert, Jamil; Yin Yongbai; McKenzie, David R.; Law, Sue; Suchowerska, Natalka

    2009-06-20

    A Cerenkov signal is generated when energetic charged particles enter the core of an optical fiber. The Cerenkov intensity can be large enough to interfere with signals transmitted through the fiber. We determine the spectrum of the Cerenkov background signal generated in a poly(methyl methacrylate) optical fiber exposed to photon and electron therapeutic beams from a linear accelerator. This spectral measurement is relevant to discrimination of the signal from the background, as in scintillation dosimetry using optical fiber readouts. We find that the spectrum is approximated by the theoretical curve after correction for the wavelength dependent attenuation of the fiber. The spectrum does not depend significantly on the angle between the radiation beam and the axis of the fiber optic but is dependent on the depth in water at which the fiber is exposed to the beam.

  11. Determination of Flow Orientation of an Optically Active Turbulent Field by Means of a Single Beam

    DTIC Science & Technology

    2013-06-18

    optically active turbulent field was determined by Fourier transforming the wander of a laser beam propagating in the ocean. A simple physical model... Fourier transform for the situation depicted on the right and on the left, respectively. July 1, 2013 / Vol. 38, No. 13 / OPTICS LETTERS 2185 0146-9592/13...132185-03$15.00/0 © 2013 Optical Society of America to the flow (see top row of Fig. 3). However, the magni- tude of the Fourier transform, in

  12. Propagation of a cosh-Gaussian beam through an optical system in turbulent atmosphere.

    PubMed

    Chu, Xiuxiang

    2007-12-24

    The propagation of a cosh-Gaussian beam through an arbitrary ABCD optical system in turbulent atmosphere has been investigated. The analytical expressions for the average intensity at any receiver plane are obtained. As an elementary example, the average intensity and its radius at the image plane of a cosh-Gaussian beam through a thin lens are studied. To show the effects of a lens on the average intensity and the intensity radius of the laser beam in turbulent atmosphere, the properties of a collimated cosh-Gaussian beam and a focused cosh-Gaussian beam for direct propagation in turbulent atmosphere are studied and numerically calculated. The average intensity profiles of a cosh-Gaussian beam through a lens can have a shape similar to that of the initial beam for a longer propagation distance than that of a collimated cosh-Gaussian beam for direct propagation. With the increment in the propagation distance, the average intensity radius at the image plane of a cosh-Gaussian beam through a thin lens will be smaller than that at the focal plane of a focused cosh-Gaussian beam for direct propagation. Meanwhile, the intensity distributions at the image plane of a cosh-Gaussian beam through a lens with different w(0) and Omega(0) are also studied.

  13. Optical bistability based on nonlinear oblique reflection of light beams from a screen with an aperture on its axis

    SciTech Connect

    Nikitenko, K Yu; Trofimov, V A

    1999-02-28

    It is shown that, in principle, optical bistability can be based on a nonlinear interaction of noncollinearly propagating beams when one of them is reflected from a plane screen with an aperture on its axis. The requirements to be satisfied by the interacting beams are discussed and estimates are obtained of the shortest response time of such an optically bistable system. (nonlinear optical phenomena)

  14. Grating beam splitting with liquid crystal adaptive optics

    NASA Astrophysics Data System (ADS)

    Albero, J.; Moreno, I.

    2012-07-01

    We report on the generation of equi-intense light beams from an adaptive point of view. A phase mask is generated and displayed onto a spatial light modulator, in order to divide an incoming light beam into a chosen number of beams. The use of liquid crystal spatial light modulators can introduce polarization into scalar designs as a parameter acting on the output efficiency. We reproduce the modulator optimal designs proposed theoretically in the literature and we add the polarization features. In addition, we compare this with another beam splitting technique, based on spatial multiplexing of phase masks. It spreads as low-level background noise the light concentrated on diffraction orders other than those targeted. We also demonstrate that using polarization with spatial light modulators can improve in some cases the optimal theoretical efficiencies. Experimental results agree with simulations.

  15. Random optical beam propagation in anisotropic turbulence along horizontal links.

    PubMed

    Wang, Fei; Korotkova, Olga

    2016-10-17

    Considerable amount of data has been collected in the past asserting that atmospheric turbulence has regions where it exhibits anisotropic statistics. For instance, it is known that the fluctuations in the refractive index within the first meter above the ground are typically stronger in the vertical direction compared with those in the horizontal directions. We have investigated the second-order statistical properties of a Gaussian Schell-model (GSM) beam traversing anisotropic atmospheric turbulence along a horizontal path. Analytical expression is rigorously derived for the cross-spectral density function of a GSM beam. It is shown that the spread of the beam and its coherence properties become different in two transverse directions due to anisotropy. In the limiting case when the source coherence width becomes infinite our results reduce to those for Gaussian beam propagation. Source partial coherence is shown to mitigate anisotropy at sub-kilometer distances.

  16. Fourier optics along a hybrid optical fiber for Bessel-like beam generation and its applications in multiple-particle trapping.

    PubMed

    Kim, Jongki; Jeong, Yoonseob; Lee, Sejin; Ha, Woosung; Shin, Jeon-Soo; Oh, Kyunghwan

    2012-02-15

    Highly efficient Bessel-like beam generation was achieved based on a new all-fiber method that implements Fourier transformation of a micro annular aperture along a concatenated composite optical fiber. The beam showed unique characteristics of tilted washboard optical potential in the transverse plane and sustained a nondiffracting length over 400 μm along the axial direction. Optical trapping of multiple dielectric particles and living Jurkat cells were successfully demonstrated along the axial direction of the beam in the water.

  17. Optical torque on a magneto-dielectric Rayleigh absorptive sphere by a vector Bessel (vortex) beam

    NASA Astrophysics Data System (ADS)

    Li, Renxian; Yang, Ruiping; Ding, Chunying; Mitri, F. G.

    2017-04-01

    The optical torque exerted on an absorptive megneto-dielectric sphere by an axicon-generated vector Bessel (vortex) beam with selected polarizations is investigated in the framework of the dipole approximation. The total optical torque is expressed as the sum of orbital and spin torques. The axial orbital torque component is calculated from the z-component of the cross-product of the vector position r and the optical force exerted on the sphere F. Depending on the beam characteristics (such as the half-cone angle and polarization type) and the physical properties of the sphere, it is shown here that the axial orbital torque vanishes before reversing sign, indicating a counter-intuitive orbital motion in opposite handedness of the angular momentum carried by the incident waves. Moreover, analytical formulas for the spin torque, which is divided into spin torques induced by electric and magnetic dipoles, are derived. The corresponding components of both the optical spin and orbital torques are numerically calculated, and the effects of polarization, the order of the beam, and half-cone angle are discussed in detail. The left-handed (i.e., negative) optical torque is discussed, and the conditions for generating optical spin and orbital torque sign reversal are numerically investigated. The transverse optical spin torque has a vortex-like character, whose direction depends on the polarization, the half-cone angle, and the order of the beam. Numerical results also show that the vortex direction depends on the radial position of the particle in the transverse plane. This means that a sphere may rotate with different directions when it moves radially. Potential applications are in particle manipulation and rotation, single beam optical tweezers, and other emergent technologies using vector Bessel beams on a small magneto-dielectric (nano) particle.

  18. Crosstalk elimination in the detection of dual-beam optical tweezers by spatial filtering

    SciTech Connect

    Ott, Dino; Oddershede, Lene B.; Reihani, S. Nader S.

    2014-05-15

    In dual-beam optical tweezers, the accuracy of position and force measurements is often compromised by crosstalk between the two detected signals, this crosstalk leading to systematic and significant errors on the measured forces and distances. This is true both for dual-beam optical traps where the splitting of the two traps is done by polarization optics and for dual optical traps constructed by other methods, e.g., holographic tweezers. If the two traps are orthogonally polarized, most often crosstalk is minimized by inserting polarization optics in front of the detector; however, this method is not perfect because of the de-polarization of the trapping beam introduced by the required high numerical aperture optics. Here we present a simple and easy-to-implement method to efficiently eliminate crosstalk. The method is based on spatial filtering by simply inserting a pinhole at the correct position and is highly compatible with standard back focal plane photodiode based detection of position and force. Our spatial filtering method reduces crosstalk up to five times better than polarization filtering alone. The effectiveness is dependent on pinhole size and distance between the traps and is here quantified experimentally and reproduced by theoretical modeling. The method here proposed will improve the accuracy of force-distance measurements, e.g., of single molecules, performed by dual-beam optical traps and hence give much more scientific value for the experimental efforts.

  19. Arrangement for multiplexing and intensity splitting light beams for interface into fiber optic cables

    DOEpatents

    Johnson, Steve A.

    1990-01-01

    An arrangement especially suitable for use in a laser apparatus for converting a plurality of different input light beams, for example copper vapor laser beams, into a plurality of substantially identical light beams is disclosed herein. This arrangement utilizes an optical mixing bar which is preferably integrally formed as a single unit and which includes a main body for mixing light therein, a flat input surface on one end of the main body, and a multi-faceted output face on the opposite end of the main body. This arrangement also includes means for directing the plurality of different input light beams onto the input face of the mixing base, whereby to cause the different beams to mix within the main body of the mixing bar and exit the latter from its multi-faceted output face as the desired plurality of substantially identical output beams.

  20. Effect of secondary ions on the electron beam optics in the Recycler Electron Cooler

    SciTech Connect

    Shemyakin, A.; Prost, L.; Saewert, G.; /Fermilab

    2010-05-01

    Antiprotons in Fermilab's Recycler ring are cooled by a 4.3 MeV, 0.1-0.5 A DC electron beam (as well as by a stochastic cooling system). The unique combination of the relativistic energy ({gamma} = 9.49), an Ampere-range DC beam, and a relatively weak focusing makes the cooling efficiency particularly sensitive to ion neutralization. A capability to clear ions was recently implemented by way of interrupting the electron beam for 1-30 {micro}s with a repetition rate of up to 40 Hz. The cooling properties of the electron beam were analyzed with drag rate measurements and showed that accumulated ions significantly affect the beam optics. For a beam current of 0.3 A, the longitudinal cooling rate was increased by factor of {approx}2 when ions were removed.

  1. Scattering of a tightly focused beam by an optically trapped particle

    SciTech Connect

    Lock, James A.; Wrbanek, Susan Y.; Weiland, Kenneth E

    2006-05-20

    Near-forward scattering of an optically trapped 5-{mu}m-radius polystyrene latex sphere by the trapping beam was examined both theoretically and experimentally. Since the trapping beam is tightly focused, the beam fields superpose and interfere with the scattered fields in the forward hemisphere. The observed light intensity consists of a series of concentric bright and dark fringes centered about the forward-scattering direction. Both the number of fringes and their contrast depend on the position of the trapping beam focal waist with respect to the sphere. The fringes are caused by diffraction that is due to the truncation of the tail of the trapping beam as the beam is transmitted through the sphere.

  2. Optical beam interactions with a periodic array of Fresnel zone plates

    NASA Astrophysics Data System (ADS)

    Roszkiewicz, A.; Nasalski, W.

    2014-08-01

    The interactions of first-order elegant Laguerre-Gaussian beams (ELG) with a two-dimensional periodic array are analysed theoretically and numerically. The structure consists of a periodic composition of two-zone Fresnel plates engraved in a silver film. The beam field is composed of periodic sequences of beams of circular or polar polarization incidence upon the structure. The beam axes coincide with the symmetry axes of every fourth Fresnel zone plate placed periodically along two orthogonal coordinates of a horizontal plane of the structure. It is shown that the beam-structure interaction results in substantial cross-polarization coupling, higher-order mode excitation, strong focussing and the extraordinary transmission of the optical field. An interpretation of the results is given per an analogy to the beam-structure interactions observed at planar, homogeneous and isotropic dielectric interfaces and layers.

  3. Measurement of Electron Beam Emittance Using Optical Transition Radiation and Development of a Diffuse Screen Electron Beam Monitor

    DTIC Science & Technology

    1990-12-01

    Zerodur ,irror, 2" relfects light. 1OZ20BD.1; 20th wave zerodur mirror , 1" reflects light. LS-35; 3’ x 5’ optical breadboard; for mounting components...profile measurements using the diffuse screen were compared with measurements using a front surface mirror and a fluorescent screen. The 20 DISTRIBUTION...Beam current and profile measurements using the diffuse screen were compared with measurements using a front surface mirror and a fluorescent screen

  4. Generation of a Cold Atom Beam from a Pyramidal Magneto-Optical Trap

    NASA Technical Reports Server (NTRS)

    Kohel, J.; Thompson, R. J.; Seidel, D. J.; Klipstein, W. M.; Maleki, L.; Bliss, J.; Libbrecht, K. G.

    2000-01-01

    Techniques to generate cold atom beams are of great interest in a variety of applications, from atomic frequency standards and atom optics to experimental studies of Bose-Einstein condensation. Cold atom beams have been produced by slowing thermal atomic beams using the Zeeman-slowing technique or chirped lasers, or using laser-cooling techniques to extract a slow atomic beam from the background gas in a low-pressure vapor cell. These laser-cooling techniques include "atomic funnels" or two-dimensional magneto-optical traps, as well as a variation of the conventional vapor cell magneto-optical trap called the "low-velocity intense source" (LVIS). Variations of the LVIS have been realized with unique trap geometries such as conical or pyramidal mirror traps. The present work implements a simple and robust design based on the pyramidal trap geometry and allows use of a single large diameter (beam to obtain large capture rates of atoms from the background vapor. The four 45 deg mirrors are truncated just before the apex of the pyramid, and the 1 sq cm region at the center of the incident laser beam is retro-reflected by lambda /4 plate with a high-reflectance gold coating on the second surface. A small (1 mm diameter) hole in this retro-optic forms an extraction column for the atoms while maintaining a low conductance between the source region and an adjacent UHV chamber.

  5. Evaluation of the OSC-TV iterative reconstruction algorithm for cone-beam optical CT

    SciTech Connect

    Matenine, Dmitri Mascolo-Fortin, Julia; Goussard, Yves

    2015-11-15

    Purpose: The present work evaluates an iterative reconstruction approach, namely, the ordered subsets convex (OSC) algorithm with regularization via total variation (TV) minimization in the field of cone-beam optical computed tomography (optical CT). One of the uses of optical CT is gel-based 3D dosimetry for radiation therapy, where it is employed to map dose distributions in radiosensitive gels. Model-based iterative reconstruction may improve optical CT image quality and contribute to a wider use of optical CT in clinical gel dosimetry. Methods: This algorithm was evaluated using experimental data acquired by a cone-beam optical CT system, as well as complementary numerical simulations. A fast GPU implementation of OSC-TV was used to achieve reconstruction times comparable to those of conventional filtered backprojection. Images obtained via OSC-TV were compared with the corresponding filtered backprojections. Spatial resolution and uniformity phantoms were scanned and respective reconstructions were subject to evaluation of the modulation transfer function, image uniformity, and accuracy. The artifacts due to refraction and total signal loss from opaque objects were also studied. Results: The cone-beam optical CT data reconstructions showed that OSC-TV outperforms filtered backprojection in terms of image quality, thanks to a model-based simulation of the photon attenuation process. It was shown to significantly improve the image spatial resolution and reduce image noise. The accuracy of the estimation of linear attenuation coefficients remained similar to that obtained via filtered backprojection. Certain image artifacts due to opaque objects were reduced. Nevertheless, the common artifact due to the gel container walls could not be eliminated. Conclusions: The use of iterative reconstruction improves cone-beam optical CT image quality in many ways. The comparisons between OSC-TV and filtered backprojection presented in this paper demonstrate that OSC-TV can

  6. OTR Measurements and Modeling of the Electron Beam Optics at the E-Cooling Facility

    NASA Astrophysics Data System (ADS)

    Warner, A.; Burov, A.; Carlson, K.; Kazakevich, G.; Nagaitsev, S.; Prost, L.; Sutherland, M.; Tiunov, M.

    2006-03-01

    Optics of the electron beam accelerated in the Pelletron, intended for the electron cooling of 8.9 GeV antiprotons in the Fermilab recycler storage ring, has been studied. The beam profile parameters were measured under the accelerating section using Optical Transition Radiation (OTR) monitor. The monitor employs a highly-reflective 2 inch-diameter aluminum OTR-screen with a thickness of 5 μm and a digital CCD camera. The measurements were done in a pulse-signal mode in the beam current range of 0.03-0.8 A and at pulse durations ranging from 1 μs to 4 μs. Differential profiles measured in pulsed mode are compared with results obtained by modeling of the DC beam dynamics from the Pelletron cathode to the OTR monitor. The modeling was done with SAM, ULTRASAM and BEAM programs. An adjustment of the magnetic fields in the lenses of the accelerating section was done in the simulations. The simulated electron beam optics downstream of the accelerating section was in good agreement with the measurements made with pulsed beam.

  7. Methods of optical diagnostics of electron-positron beams and interaction between plasma and high-current electron beam

    NASA Astrophysics Data System (ADS)

    Vyacheslavov, L. N.; Ivantsivskii, M. V.; Meshkov, O. I.; Popov, S. S.; Smaluk, V. V.

    2012-03-01

    Optical diagnostics is widely used, both in plasma-physics experiments and in measuring parameters of electron and positron beams in accelerators. In doing so, the approaches with the same methodological base are often applied, which is explained by similarity of certain properties of objects under study despite the fact that these fields of physics are absolutely specific and require using the specialized techniques. The possibility of close contacts and cooperation among scientists concerned with similar problems in different fields of physics contributes to the fruitful exchange of ideas and helps to overcome these problems. It is especially characteristic of the Budker Institute of Nuclear Physics, Siberian Branch of Russian Academy of Sciences, which is famous for pioneering works in the field of electron-positron colliders and controlled thermonuclear fusion. The first part of this paper presents a review of optical diagnostics of the stationary beam parameters in cyclic accelerators of electrons and positrons. The only techniques considered are those that became the recognized tools at colliders and storage rings of the latest generation, without which the routine operation of the facility is difficult to imagine. The second part of the paper describes optical diagnostics used in experiments of heating the plasma by a high-current electron beam.

  8. Multiple Beam Correlation Using Single-Mode Fiber Optics with Application to Interferometric Imaging

    NASA Astrophysics Data System (ADS)

    Shaklan, Stuart Bruce

    A study of the application of single-mode fiber optics to the multiple-beam interferometric recombination problem is presented. In the laboratory, the fibers have been used in wide bandwidth, two-arm, Mach-Zehnder test interferometers as well as a 5-telescope imaging interferometer connected to an all-fiber beam combiner. Based upon these experiments and some theoretical studies it is shown that fiber optics and fiber optic components such as directional couplers provide an excellent alternative to conventional optics such as mirrors, beamsplitters, and relay lenses. The equations describing the measurement of the complex degree of coherence in an interferometer with a single-mode fiber in each arm are derived. The equations reveal an important feature of the fibers: they filter phase fluctuations due to aberrations and turbulence at the input and convert them to intensity fluctuations at the output. This leads to a simplification of the calibration of measured visibilities. The coupling efficiency of light which has passed through a turbulent atmosphere is also studied as a function of fiber parameters and turbulence conditions for both image motion stabilized and non-stabilized cases. For the former case, coupling efficiency remains greater than 50% as long as telescope diameter is no larger than the turbulence coherence length. Beam combination architectures using arrays of directional couplers are fully discussed. Arrays accommodating up to 20 input beams are presented. The arrays require only N detector pixels for N input beams. A scheme of temporal multiplexing of the phase of each beam is used to identify individual fringe pairs. One possible scheme allows wide bandwidths even for large numbers of beams. A 5-telescope interferometer has been constructed and connected to an all-fiber beam combiner. Two extended objects were observed and reconstructed using standard radio astronomy VLBI software. The interferometer and beam combiner had good thermal and

  9. Novel beam delivery system for microvia drilling using holographic and refractive optics

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd E.; Ohar, Orest P.

    2003-07-01

    The research and development of the optical system described was due in part to the virtual stalemate of current microvia dirlling technology within the High Density Interconnect market. The desire by industry to acquire faster processes for drilling microvias led to our research in the utilization of hybrid optical systems, where standard refractive and computer generated diffractive optics could be meshed to create a system that would out perform the current technology in the marketplace. The outcome of this work is covered in the following paper and will, at the outset, briefly cover the targeted market segment for which the beam delivery system was developed, as well as its general capabilities. The paper will cover the basic architecture and technology behind the laser optical beam delivery system, as well as the unique components that make up the assembly. Each of the optical elements within the system will be briefly described, and the CGH elements will be briefly explained, including a description of the software used. The laser beam characteristics at several points along the beam delivery will be discussed, as well as the final image formed at the target plane where the microvia is drilled. Specific performance details will be shared with regards to component efficiency, i.e. diffraction efficiency losses, as well as total system performance throughout the beam line. The final section will cover materials processing, including the remarkable process rate increases and microvia hole quality achieved.

  10. Off-axis mirror based optical system design for circularization, collimation, and expansion of elliptical laser beams.

    PubMed

    Serkan, Mert; Kirkici, Hulya; Cetinkaya, Hakan

    2007-08-01

    In this paper, we present two optical system design methods for beam circularization, collimation, and expansion of semiconductor laser output beam for possible application in LIDAR systems. Two different optical mirror systems are investigated: an off-axis hyperbolic/parabolic mirror system and an off-axis parabolic mirror system. Equations specific to these mirror systems are derived and computer package programs such as ZEMAX and MATLAB are used to simulate the optical designs. The beam reshaping results are presented.

  11. Off-axis mirror based optical system design for circularization, collimation, and expansion of elliptical laser beams

    NASA Astrophysics Data System (ADS)

    Serkan, Mert; Kirkici, Hulya; Cetinkaya, Hakan

    2007-08-01

    In this paper, we present two optical system design methods for beam circularization, collimation, and expansion of semiconductor laser output beam for possible application in LIDAR systems. Two different optical mirror systems are investigated: an off-axis hyperbolic/parabolic mirror system and an off-axis parabolic mirror system. Equations specific to these mirror systems are derived and computer package programs such as ZEMAX and MATLAB are used to simulate the optical designs. The beam reshaping results are presented.

  12. Note: Investigation of atom transfer using a red-detuned push beam in a double magneto-optical trap setup.

    PubMed

    Ram, S P; Mishra, S R; Tiwari, S K; Mehendale, S C

    2011-12-01

    We present our results on transfer of cold (87)Rb atoms from a vapor cell magneto-optical trap to ultrahigh vacuum magneto-optical trap (UHV-MOT) using a red-detuned continuous wave push beam in a double-magneto-optical trap setup. We find that use of retro-reflected red-detuned push laser beam results in higher number in UHV-MOT than the number obtained without retro-reflection of push beam.

  13. Secure transmission of static and dynamic images via chaotic encryption in acousto-optic hybrid feedback with profiled light beams

    NASA Astrophysics Data System (ADS)

    Chatterjee, Monish R.; Almehmadi, Fares S.

    2015-01-01

    Secure information encryption via acousto-optic (AO) chaos with profiled optical beams indicates substantially better performance in terms of system robustness. This paper examines encryption of static and time-varying (video) images onto AO chaotic carriers using Gaussian-profile beams with diffracted data numerically generated using transfer functions. The use of profiled beams leads to considerable improvement in the encrypted signal. While static image encryption exhibits parameter tolerances within about +/-10% for uniform optical beams, profiled beams reduce the tolerance to less than 1%, thereby vastly improving both the overall security of the transmitted information as well as the quality of the image retrieval.

  14. Mitigation of Laser Beam Scintillation in Free-Space Optical Communication Systems Through Coherence-Reducing Optical Materials

    NASA Technical Reports Server (NTRS)

    Renner, Christoffer J.

    2005-01-01

    Free-space optical communication systems (also known as lasercom systems) offer several performance advantages over traditional radio frequency communication systems. These advantages include increased data rates and reduced operating power and system weight. One serious limiting factor in a lasercom system is Optical turbulence in Earth's atmosphere. This turbulence breaks up the laser beam used to transmit the information into multiple segments that interfere with each other when the beam is focused onto the receiver. This interference pattern at the receiver changes with time causing fluctuations in the received optical intensity (scintillation). Scintillation leads to intermittent losses of the signal and an overall reduction in the lasercom system's performance. Since scintillation is a coherent effect, reducing the spatial and temporal coherence of the laser beam will reduce the scintillation. Transmitting a laser beam through certain materials is thought to reduce its coherence. Materials that were tested included: sapphire, BK7 glass, fused silica and others. The spatial and temporal coherence of the laser beam was determined by examining the interference patterns (fringes) it formed when interacting with various interferometers and etalons.

  15. Theoretical considerations on imaging of micron size electron beam with optical transition radiation

    NASA Astrophysics Data System (ADS)

    Xiang, Dao; Huang, Wen-Hui

    2007-01-01

    Optical transition radiation (OTR) has been widely used to image electron beam profile. In this paper, we systematically investigated the issues related to imaging of electron beam with OTR. It is found that the point-spread function (PSF) largely depends on the acceptance angle of the lens and is only very weakly dependent on beam energy and the distance from the OTR target to the lens. This excludes the potential obstacles to imaging of high-energy electron beam for which, the photons are emitted in a relatively small cone and the far field condition is hard to fulfill. The image of a whole beam is found by convoluting the real beam distribution with the PSF. It is shown that for micron size beam, the image formed with OTR largely deviates from the real beam distribution. And the real beam distribution could be restored from deconvoluting the image with the PSF. The effectiveness of the restoration is demonstrated, which opens up the possibility of measuring micron size beam profile with OTR.

  16. Analytic beam spread function for ocean optics applications

    NASA Astrophysics Data System (ADS)

    Sanchez, Richard; McCormick, Norman J.

    2002-10-01

    A discrete ordinates code is developed with which to compute the beam spread function (BSF) without invoking the small-angle scattering approximation or performing Monte Carlo calculations. The computed BSF is used to predict the response of a detector versus its distance to the origin of a highly collimated beam, its angle with respect to the beam, and the two local angles that specify the detector orientation. Numerical results have been obtained for water models that simulate a clear ocean, a coastal ocean, and a turbid harbor. Six orders of magnitude or more change in the detector response caused by scattered photons can be predicted for different detector locations while simultaneously obtaining small changes for different detector orientations. This capability is useful for assessment of the sensitivity of the detector response to the interpretation of time-independent underwater imaging systems or visibility models.

  17. Analytic beam spread function for ocean optics applications.

    PubMed

    Sanchez, Richard; McCormick, Norman J

    2002-10-20

    A discrete ordinates code is developed with which to compute the beam spread function (BSF) without invoking the small-angle scattering approximation or performing Monte Carlo calculations. The computed BSF is used to predict the response of a detector versus its distance to the origin of a highly collimated beam, its angle with respect to the beam, and the two local angles that specify the detector orientation. Numerical results have been obtained for water models that simulate a clear ocean, a coastal ocean, and a turbid harbor. Six orders of magnitude or more change in the detector response caused by scattered photons can be predicted for different detector locations while simultaneously obtaining small changes for different detector orientations. This capability is useful for assessment of the sensitivity of the detector response to the interpretation of time-independent underwater imaging systems or visibility models.

  18. Approach to improve beam quality of inter-satellite optical communication system based on diffractive optical elements.

    PubMed

    Tan, Liying; Yu, Jianjie; Ma, Jing; Yang, Yuqiang; Li, Mi; Jiang, Yijun; Liu, Jianfeng; Han, Qiqi

    2009-04-13

    For inter-satellite optical communication transmitter with reflective telescope of two-mirrors on axis, a large mount of the transmitted energy will be blocked by central obscuration of the secondary mirror. In this paper, a novel scheme based on diffractive optical element (DOE) is introduced to avoid it. This scheme includes one diffractive beam shaper and another diffractive phase corrector, which can diffract the obscured part of transmitted beam into the domain unobscured by the secondary mirror. The proposed approach is firstly researched with a fixed obscuration ratio of 1/4. Numerical simulation shows that the emission efficiency of new figuration is 99.99%; the beam divergence from the novel inter-satellite optical communication transmitter is unchanged; and the peak intensity of receiver plane is increased about 31% compared with the typical configuration. Then the intensy patterns of receiver plane are analyzed with various obscuration ratio, the corresponding numerical modelling reveals that the intensity patterns with various obscuration ratio are nearly identical, but the amplify of relative peak intensity is getting down with the growth of obscuration ratio. This work can improve the beam quality of inter-satellite optical communication system without affecting any other functionality.

  19. 30 Watts mid-infrared optical parametric oscillator based on spectral beam combination technology

    NASA Astrophysics Data System (ADS)

    Shang, Yaping; Wang, Peng; Li, Xiao; Xu, Xiaojun

    2017-01-01

    Limited by the thermal effects and the laser-induced damage characteristics of the non-linear crystals, mid-infrared (MIR) output power of single optical parametric oscillator (OPO) is hard to get further promoted with excellent beam quality. An alternative solution is the multiple-beams combination technology, which exactly provided an effective approach for decreasing the thermal effects and the damage risk of the OPO system under high power operation. In this letter, the experimental study on the spectral beam combination of three idler MIR lasers was carried out for the first time. An optical parametric system with MIR output power of 30 W at 3130nm, 3352nm, and 3670nm was finally obtained. Experimental results indicated that the beam quality M2 factors of the combined laser were measured to be 1.76 and 2.42 in the horizontal and vertical directions, respectively, which confirmed the feasibility of the schematic design.

  20. Lidar Electro-Optic Beam Switch with a Liquid Crystal Variable Retarder

    NASA Technical Reports Server (NTRS)

    Baer, James

    2012-01-01

    A document discusses a liquid crystal variable retarder, an electro-optic element that changes the polarization of an optical beam in response to a low-voltage electronic signal. This device can be fabricated so that the element creates, among other states, a half-wave of retardance that can be reduced to a very small retardance. When aligned to a polarized source, this can act to rotate the polarization by 90 in one state, but generate no rotation in the other state. If the beam is then incident on a polarization beam splitter, it will efficiently switch from one path to the other when the voltage is applied. The laser beam switching system has no moving parts, improving reliability over mechanical switching. It is low cost, tolerant of high laser power density, and needs only simple drive electronics, minimizing the required system resources.

  1. Design of optics for the final focus test beam at SLAC

    SciTech Connect

    Oide, Katsunobu

    1989-05-01

    The goal of the Final Focus Test Beam experiment (FFTB) is to produce an electron beam spot of 1 ..mu..m by 60 nm in transverse dimensions. In the future linear collider of TeV region (TLC), a typical spot size of 100 nm by 1 nm at the interaction point is required to get luminosity of 1 /times/ 10/sup 34/cm/sup /minus/2/s/sup /minus/1/. This spot size is about 1/1000 of the SLC in the vertical dimension, and is demanding for an optics design, alignments, beam diagnostics, and tuning procedures. The spot size of the FFTB will be an important next step from the SLC toward the TLC. This paper describes the design of the beam optics. 11 refs., 2 figs., 1 tab.

  2. Quantification of optical turbulence in the ocean and its effects on beam propagation.

    PubMed

    Nootz, Gero; Jarosz, Ewa; Dalgleish, Fraser R; Hou, Weilin

    2016-11-01

    The influence of optically active turbulence on the propagation of laser beams is investigated in clear ocean water over a path length of 8.75 m. The measurement apparatus is described and the effects of optical turbulence on the laser beam are presented. The index of refraction structure constant is extracted from the beam deflection and the results are compared to independently made measures of the turbulence strength (Cn2) by a vertical microstructure profiler. Here we present values of Cn2 taken from aboard the R/V Walton Smith during the Bahamas optical turbulence exercise (BOTEX) in the Tongue of the Ocean between June 30 and July 12, 2011, spanning a range from 10-14 to 10-10  m-2/3. To the best of our knowledge, this is the first time such measurements are reported for the ocean.

  3. Avoiding disentanglement of multipartite entangled optical beams with a correlated noisy channel

    PubMed Central

    Deng, Xiaowei; Tian, Caixing; Su, Xiaolong; Xie, Changde

    2017-01-01

    A quantum communication network can be constructed by distributing a multipartite entangled state to space-separated nodes. Entangled optical beams with highest flying speed and measurable brightness can be used as carriers to convey information in quantum communication networks. Losses and noises existing in real communication channels will reduce or even totally destroy entanglement. The phenomenon of disentanglement will result in the complete failure of quantum communication. Here, we present the experimental demonstrations on the disentanglement and the entanglement revival of tripartite entangled optical beams used in a quantum network. We experimentally demonstrate that symmetric tripartite entangled optical beams are robust in pure lossy but noiseless channels. In a noisy channel, the excess noise will lead to the disentanglement and the destroyed entanglement can be revived by the use of a correlated noisy channel (non-Markovian environment). The presented results provide useful technical references for establishing quantum networks. PMID:28295024

  4. Dynamics analysis of microsphere in a dual-beam fiber-optic trap with transverse offset.

    PubMed

    Chen, Xinlin; Xiao, Guangzong; Luo, Hui; Xiong, Wei; Yang, Kaiyong

    2016-04-04

    A comprehensive dynamics analysis of microsphere has been presented in a dual-beam fiber-optic trap with transverse offset. As the offset distance between two counterpropagating beams increases, the motion type of the microsphere starts with capture, then spiral motion, then orbital rotation, and ends with escape. We analyze the transformation process and mechanism of the four motion types based on ray optics approximation. Dynamic simulations show that the existence of critical offset distances at which different motion types transform. The result is an important step toward explaining physical phenomena in a dual-beam fiber-optic trap with transverse offset, and is generally applicable to achieving controllable motions of microspheres in integrated systems, such as microfluidic systems and lab-on-a-chip systems.

  5. Avoiding disentanglement of multipartite entangled optical beams with a correlated noisy channel

    NASA Astrophysics Data System (ADS)

    Deng, Xiaowei; Tian, Caixing; Su, Xiaolong; Xie, Changde

    2017-03-01

    A quantum communication network can be constructed by distributing a multipartite entangled state to space-separated nodes. Entangled optical beams with highest flying speed and measurable brightness can be used as carriers to convey information in quantum communication networks. Losses and noises existing in real communication channels will reduce or even totally destroy entanglement. The phenomenon of disentanglement will result in the complete failure of quantum communication. Here, we present the experimental demonstrations on the disentanglement and the entanglement revival of tripartite entangled optical beams used in a quantum network. We experimentally demonstrate that symmetric tripartite entangled optical beams are robust in pure lossy but noiseless channels. In a noisy channel, the excess noise will lead to the disentanglement and the destroyed entanglement can be revived by the use of a correlated noisy channel (non-Markovian environment). The presented results provide useful technical references for establishing quantum networks.

  6. Statistical description of the free-space propagation of highly aberrated optical beams.

    PubMed

    Mani, Ali; Wang, Meng; Moin, Parviz

    2006-12-01

    The free-space propagation of initially aberrated optical beams is considered with an emphasis on aero-optical applications. An exact statistical solution of the paraxial wave equation is derived that can be used to obtain statistics of the beam such as beam center, spread, and higher-order statistics as algebraic functions of propagation distance, wavelength, and statistics of the initial wavefront. Correlations between the proposed description and intensity-based statistics, such as the Strehl ratio, are investigated. It is found that the root-mean-square (rms) of the gradient of the wavefront plays an important role in causing coherence degradation and that the rms of the wavefront error is not always an appropriate measure of the degradation. To illustrate the use of this statistical tool, index of refraction data from a numerical simulation of compressible flow over a cylinder are employed to perform an aero-optical analysis.

  7. Beam shaping in high-power broad-area quantum cascade lasers using optical feedback

    PubMed Central

    Ferré, Simon; Jumpertz, Louise; Carras, Mathieu; Ferreira, Robson; Grillot, Frédéric

    2017-01-01

    Broad-area quantum cascade lasers with high output powers are highly desirable sources for various applications including infrared countermeasures. However, such structures suffer from strongly deteriorated beam quality due to multimode behavior, diffraction of light and self-focusing. Quantum cascade lasers presenting high performances in terms of power and heat-load dissipation are reported and their response to a nonlinear control based on optical feedback is studied. Applying optical feedback enables to efficiently tailor its near-field beam profile. The different cavity modes are sequentially excited by shifting the feedback mirror angle. Further control of the near-field profile is demonstrated using spatial filtering. The impact of an inhomogeneous gain as well as the influence of the cavity width are investigated. Compared to existing technologies, that are complex and costly, beam shaping with optical feedback is a more flexible solution to obtain high-quality mid-infrared sources. PMID:28287175

  8. On-chip silicon optical phased array for two-dimensional beam steering.

    PubMed

    Kwong, David; Hosseini, Amir; Covey, John; Zhang, Yang; Xu, Xiaochuan; Subbaraman, Harish; Chen, Ray T

    2014-02-15

    A 16-element optical phased array integrated on chip is presented for achieving two-dimensional (2D) optical beam steering. The device is fabricated on the silicon-on-insulator platform with a 250 nm silicon device layer. Steering is achieved via a combination of wavelength tuning and thermo-optic phase shifting with a switching power of P(π)=20  mW per channel. Using a silicon waveguide grating with a polycrystalline silicon overlay enables narrow far field beam widths while mitigating the precise etching needed for conventional shallow etch gratings. Using this system, 2D steering across a 20°×15° field of view is achieved with a sidelobe level better than 10 dB and with beam widths of 1.2°×0.5°.

  9. Optical material removal property analysis of Ar+ and Kr+ in ion beam figuring

    NASA Astrophysics Data System (ADS)

    Lu, Ying; Xie, Xu Hui; Zhou, Lin; Dai, Zuo Cai; Chen, Gui Yang

    2016-10-01

    Ion beam figuring (IBF) provides a highly deterministic method for the final precision figuring of optical components. According to the Sigmund sputtering theory, the mass of incident ions is an important factor to the sputtering rate and the optical surface quality. Both Ar+ and Kr+ are alternative ions in IBF, but the mass of Kr+ equals two times that of Ar+. In order to achieve the nanometer and sub-nanometer precision fabrication with IBF, the optical material removal property of Ar+ and Kr+ ions was researched. The bombardment process had been simulated with the software TRIM, and the sputtering yield of Ar+ and Kr+ ions for different incident angles was calculated. Then the removal function experiments on Si were conducted. The simulations and experiments result indicated that Ar+ ion beam achieves higher removal rate at 0° incident angle, but Kr+ ion beam performs more efficiently when the incident angle gets across a critical point.

  10. Steerable pencil beams for multi-Gbps indoor optical wireless communication.

    PubMed

    Oh, C W; Tangdiongga, E; Koonen, A M J

    2014-09-15

    We report a novel optical wireless communication (OWC) system solution that supports multi-Gbps (Gigabit-per-second) capacity for indoors. Narrow beams, termed as pencil beams, are directed to wireless users using a tunable laser and a passive diffractive optical element. This enables a wide coverage of ultra-high-capacity communication links to serve multiple network users simultaneously. Experimental results demonstrating data rates of up to 10 Gbps, with on-off keying modulation format, over a distance of more than 2.5 m, are reported. Error-free links beam-steered over a total wavelength range of 130 nm, with steering angle of 17.16°, have been achieved. This system is proposed for short-range OWC and is promising for seamless integration in in-building optical networks.

  11. Beam-shaping via femtosecond laser-modified optical fibre end faces

    NASA Astrophysics Data System (ADS)

    Ioannou, A.; Polis, M.; Lacraz, A.; Theodosiou, A.; Kalli, K.

    2016-04-01

    We present the results of investigations regarding laser micro-structuring of single mode optical fibres by direct access of the fibre end face and compare this with inscription in planar samples. We combine a high numerical aperture objective and femtosecond laser radiation at visible wavelengths to examine the spatial limits of direct writing and structuring at the surface of the optical fibre. We realise a number of interesting devices from one- and two-dimensional grating structures, to Bessel, Airy and vortex beam generators. We show the versatility of this simple but effective inscription method, where we demonstrate classic multiple slit diffraction patterns and patterns for non-diffracting beams, confirming that the flexible direct write method using femtosecond lasers can be to produce binary masks that can lead to beam shaping using a method that is applicable to all types of planar samples and through fine control of laser parameters to multi-mode and singlemode optical fibres.

  12. Beam shaping in high-power broad-area quantum cascade lasers using optical feedback

    NASA Astrophysics Data System (ADS)

    Ferré, Simon; Jumpertz, Louise; Carras, Mathieu; Ferreira, Robson; Grillot, Frédéric

    2017-03-01

    Broad-area quantum cascade lasers with high output powers are highly desirable sources for various applications including infrared countermeasures. However, such structures suffer from strongly deteriorated beam quality due to multimode behavior, diffraction of light and self-focusing. Quantum cascade lasers presenting high performances in terms of power and heat-load dissipation are reported and their response to a nonlinear control based on optical feedback is studied. Applying optical feedback enables to efficiently tailor its near-field beam profile. The different cavity modes are sequentially excited by shifting the feedback mirror angle. Further control of the near-field profile is demonstrated using spatial filtering. The impact of an inhomogeneous gain as well as the influence of the cavity width are investigated. Compared to existing technologies, that are complex and costly, beam shaping with optical feedback is a more flexible solution to obtain high-quality mid-infrared sources.

  13. Beam shaping in high-power broad-area quantum cascade lasers using optical feedback.

    PubMed

    Ferré, Simon; Jumpertz, Louise; Carras, Mathieu; Ferreira, Robson; Grillot, Frédéric

    2017-03-13

    Broad-area quantum cascade lasers with high output powers are highly desirable sources for various applications including infrared countermeasures. However, such structures suffer from strongly deteriorated beam quality due to multimode behavior, diffraction of light and self-focusing. Quantum cascade lasers presenting high performances in terms of power and heat-load dissipation are reported and their response to a nonlinear control based on optical feedback is studied. Applying optical feedback enables to efficiently tailor its near-field beam profile. The different cavity modes are sequentially excited by shifting the feedback mirror angle. Further control of the near-field profile is demonstrated using spatial filtering. The impact of an inhomogeneous gain as well as the influence of the cavity width are investigated. Compared to existing technologies, that are complex and costly, beam shaping with optical feedback is a more flexible solution to obtain high-quality mid-infrared sources.

  14. Three-dimensional optical manipulation using four collimated intersecting laser beams.

    PubMed

    Huisken, J; Swoger, J; Stelzer, E H

    2007-04-16

    The optical Earnshaw theorem states that a small particle cannot be trapped solely by scattering forces. This limitation is overcome in a novel differential all-optical manipulator. It utilizes four collimated laser beams arranged along the axes of a tetrahedron to confine and move a microscopic sample in an aqueous medium. By adjusting the intensity of each beam individually the magnitude and direction of the optical forces acting on the sample, and via these its position, are controlled. Since only scattering forces are exploited the system is not confined to trapping near a geometrical focus, and therefore enables three-dimensional manipulation over ultra-long working distances. Latex beads 20 microm in diameter can be positioned arbitrarily within a volume defined by the overlap of the four 100 microm diameter beams. The sample is observed from four directions simultaneously, demonstrating the instrument's potential as a universal manipulator in connection with high- and isotropic-resolution light microscopy.

  15. Precision beam pointing control with jitter attenuation by optical deflector exhibiting dynamic hysteresis in COIL

    NASA Astrophysics Data System (ADS)

    Ma, Yan-Hua; Zhang, Zeng-Bao; Zhang, Zhi-Guo; Liu, Qin; He, Xin; Shi, Wen-Bo; Mao, Jian-Qin; Jin, Yu-Qi

    2015-02-01

    Due to the existence of various disturbances during the lasing process of the chemical oxygen iodine laser (COIL), the optical beam pointing performance is severely degraded. In this paper, an adaptive control methodology is proposed for the precise pointing control of the optical beam with active beam jitter rejection using a giant magnetostrictive optical deflector (GMOD) which exhibits severe dynamic hysteresis nonlinearity. In particular, a least square support vector machine (LS-SVM) based fast compensator is employed to eliminate the dynamic hysteresis without the inverse model construction. Then an improved feedforward adaptive filter is developed to deal with jitter attenuation when the full-coherent reference signal is unavailable. To improve the stability and overall robustness of the controller, especially when a large initial bias exists, a PI controller is placed in parallel with the adaptive filter. Experimental results validate the precise pointing ability of the proposed control method.

  16. Single-Beam Optical Conveyor Belt for Chiral Particles

    NASA Astrophysics Data System (ADS)

    Fernandes, David E.; Silveirinha, Mário G.

    2016-07-01

    A different paradigm is proposed to selectively manipulate and transport small engineered chiral particles and discriminate different enantiomers using unstructured chiral light. It is theoretically shown that the response of a chiral metamaterial particle may be tailored to enable an optical conveyor-belt operation with no optical traps, such that for a fixed incident light helicity the nanoparticle is either steadily pushed towards the direction of the photon flow or steadily pulled against the photon flow, independent of its position. Our findings create distinct opportunities for unconventional optical manipulations of tailored nanoparticles and may have applications in sorting racemic mixtures of artificial chiral molecules and in particle delivery.

  17. MEMS-based diffractive optical-beam-steering technology

    NASA Astrophysics Data System (ADS)

    Winick, David A.; Duewer, Bruce E.; Chaudhury, Som; Wilson, John M.; Tucker, John; Eksi, Umut; Franzon, Paul D.

    1998-03-01

    This paper presents some results from phase-1 research into developing a beam steerer based on micro-mechanical diffractive elements. The position of these elements is electrostatically controlled, to allow dynamic programming of a 2D phase function. Feasibility prototypes were constructed in the MUMPs polysilicon surface micromachine process.

  18. All-optical beam deflection method for simultaneous thermal conductivity and thermo-optic coefficient ( d n / d T ) measurements

    NASA Astrophysics Data System (ADS)

    Putnam, Shawn A.; Fairchild, Steven B.; Arends, Armando A.; Urbas, Augustine M.

    2016-05-01

    This work describes an all-optical beam deflection method to simultaneously measure the thermal conductivity ( Λ) and thermo-optic coefficient ( d n / d T ) of materials that are absorbing at λ = 10.6 μm and are transparent to semi-transparent at λ = 632.8 nm. The technique is based on the principle of measuring the beam deflection of a probe beam (632.8 nm) in the frequency-domain due to a spatially and temporally varying index gradient that is thermally induced by 50:50 split pump beam from a CO2 laser (10.6 μm). The technique and analysis methods are validated with measurements of 10 different optical materials having Λ and d n / d T properties ranging between 0.7 W/m K ≲ Λ ≲ 33.5 W/m K and -12 × 10-6 K-1 ≲ d n / d T ≲ 14 × 10-6 K-1, respectively. The described beam deflection technique is highly related to other well-established, all-optical materials characterization methods, namely, thermal lensing and photothermal deflection spectroscopy. Likewise, due to its all-optical, pump-probe nature, it is applicable to materials characterization in extreme environments with minimal errors due to black-body radiation. In addition, the measurement principle can be extended over a broad range of electromagnetic wavelengths (e.g., ultraviolet to THz) provided the required sources, detectors, and focusing elements are available.

  19. Experimental research on beam steering characteristics of liquid crystal optical phased array

    NASA Astrophysics Data System (ADS)

    Li, Man; Cai, Jun; Xu, Hong; Wang, Xiangru; Wu, Liang

    2016-01-01

    Beam steering characteristics of transmission liquid crystal optical phased array(LC-OPA) were measured using ultra precision electronic autocollimator. A continuous beam steering with a constant angular resolution in the order of 20 μrad is obtained experimentally from 0° to 6° based on the method of variable period grating (VPG).Meanwhile, the angular repeatability of less than 4 μrad (RMS) has been achieved.

  20. Improved rate control for electron-beam evaporation and evaluation of optical performance improvements.

    PubMed

    Gevelber, Michael; Xu, Bing; Smith, Douglas

    2006-03-01

    A new deposition-rate-control and electron-beam-gun (e-gun) strategy was developed that significantly reduces the growth-rate variations for e-beam-deposited SiO2 coatings. The resulting improvements in optical performance are evaluated for multilayer bandpass filters. The adverse effect of uneven silica-source depletion on coating spectral performances during long deposition runs is discussed.

  1. Database Applications to Integrate Beam Line Optics Changes with the Engineering Databases

    SciTech Connect

    Chan, A.; Bellomo, P.; Crane, G.R.; Emma, P.; Grunhaus, E.; Luchini, K.; MacGregor, I.A.; Marsh, D.S.; Pope, R.; Prickett, P.; Rago, C.; Ratcliffe, K.; Shab, T.; /SLAC

    2007-07-06

    The LCLS project databases provide key nomenclature information while integrating many engineering and physics processes in the building of an accelerator. Starting with the elements existing in the beam line optics files, the engineers add non-beam-line elements, and controls engineers assign ''Formal Device Names'' to these elements. Inventory, power supplies, racks, crates and cable plants are databases that are being integrated into the project database. This approach replaces individual spreadsheets and/or integrates standalone existing institutional databases.

  2. Applications of Ion-Beam Milling and Deposition Techniques to HEL (High Energy Laser) Optics.

    DTIC Science & Technology

    1981-11-23

    using a Twyman -Green interferometer with one leg in the vacuum deposition chamber ........ ...................... .. 14 Figure 3. Deomonstration of...of beam current and voltage. 13 b) I Figure 2. Photographs of interference pattern produced using a Twyman -Green interferometer with one leg in the...Measurements of optical surface roughness were made versus milling depth for various ion beam conditions and geometry arrangements. A Twyman -Green

  3. Stray light in cone beam optical computed tomography: II. Reduction using a convergent light source

    NASA Astrophysics Data System (ADS)

    Dekker, Kurtis H.; Battista, Jerry J.; Jordan, Kevin J.

    2016-04-01

    Optical cone beam computed tomography (CBCT) using a broad beam and CCD camera is a fast method for densitometry of 3D optical gel dosimeters. However, diffuse light sources introduce considerable stray light into the imaging system, leading to underestimation of attenuation coefficients and non-uniformities in CT images unless corrections are applied to each projection image. In this study, the light source of a commercial optical CT scanner is replaced with a convergent cone beam source consisting of almost exclusively image forming primary rays. The convergent source is achieved using a small isotropic source and a Fresnel lens. To characterize stray light effects, full-field cone beam CT imaging is compared to fan beam CT (FBCT) using a 1 cm high fan beam aperture centered on the optic axis of the system. Attenuating liquids are scanned within a large 96 mm diameter uniform phantom and in a small 13.5 mm diameter finger phantom. For the uniform phantom, cone and fan beam CT attenuation coefficients agree within a maximum deviation of (1  ±  2)% between mean values over a wide range from 0.036 to 0.43 cm-1. For the finger phantom, agreement is found with a maximum deviation of (4  ±  2)% between mean values over a range of 0.1-0.47 cm-1. With the convergent source, artifacts associated with refractive index mismatch and vessel optical features are more pronounced. Further optimization of the source size to achieve a balance between quantitative accuracy and artifact reduction should enable practical, accurate 3D dosimetry, avoiding time consuming 3D scatter measurements.

  4. Stray light in cone beam optical computed tomography: II. Reduction using a convergent light source.

    PubMed

    Dekker, Kurtis H; Battista, Jerry J; Jordan, Kevin J

    2016-04-07

    Optical cone beam computed tomography (CBCT) using a broad beam and CCD camera is a fast method for densitometry of 3D optical gel dosimeters. However, diffuse light sources introduce considerable stray light into the imaging system, leading to underestimation of attenuation coefficients and non-uniformities in CT images unless corrections are applied to each projection image. In this study, the light source of a commercial optical CT scanner is replaced with a convergent cone beam source consisting of almost exclusively image forming primary rays. The convergent source is achieved using a small isotropic source and a Fresnel lens. To characterize stray light effects, full-field cone beam CT imaging is compared to fan beam CT (FBCT) using a 1 cm high fan beam aperture centered on the optic axis of the system. Attenuating liquids are scanned within a large 96 mm diameter uniform phantom and in a small 13.5 mm diameter finger phantom. For the uniform phantom, cone and fan beam CT attenuation coefficients agree within a maximum deviation of (1  ±  2)% between mean values over a wide range from 0.036 to 0.43 cm(-1). For the finger phantom, agreement is found with a maximum deviation of (4  ±  2)% between mean values over a range of 0.1-0.47 cm(-1). With the convergent source, artifacts associated with refractive index mismatch and vessel optical features are more pronounced. Further optimization of the source size to achieve a balance between quantitative accuracy and artifact reduction should enable practical, accurate 3D dosimetry, avoiding time consuming 3D scatter measurements.

  5. Optical Device, System, and Method of Generating High Angular Momentum Beams

    NASA Technical Reports Server (NTRS)

    Savchenkov, Anatoliy A. (Inventor); Matsko, Andrey B. (Inventor); Strekalov, Dmitry V. (Inventor); Grudinin, Ivan S. (Inventor); Maleki, Lute (Inventor)

    2009-01-01

    An optical device, optical system, and method of generating optical beams having high angular momenta are provided. The optical device includes a whispering gallery mode resonator defining a resonator radius and an elongated wavegWde having a length defined between a first end and a second end of the waveguide. The waveguide defines a waveguide radius which increases at least along a portion of the length of the waveguide in a direction from the first end to the second end. The waveguide radius at the first end of the waveguide is smaller than the resonator radius and the resonator is integrally formed with the first end of the waveguide.

  6. Distortion of optical wedges with a large angle of incidence in a collimated beam

    NASA Astrophysics Data System (ADS)

    Mao, Wenwei; Xu, Yuxian

    1999-04-01

    The optical wedge engenders a distortion aberration in a collimated beam in general. Presented is a set of distortion formulas and of third-order distortion formulas in the component form of TAx and TAy for optical wedges. The main dependence of the distortion as a function of the apex angle, of the incident angle of the optical axis, and of the view field of the optical wedge is established. The slope formula of a curved line, which is the image of a straight line of an optical wedge, is developed. They are suited for the large incident angle of the optical axis and the small apex angle. The analysis and calculation indicate that the image of a square for an optical wedge is in the shape of a church bell with a slightly convex or flat side rather than with a concave side.

  7. Multifunctional diffractive optical elements for the generation of higher order Bessel-like-beams

    NASA Astrophysics Data System (ADS)

    Vijayakumar, A.; Bhattacharya, Shanti

    2015-01-01

    Higher Order Bessel Beams (HOBBs) have many useful applications in optical trapping experiments. The generation of HOBBs is achieved by illuminating an axicon by a Laguerre-Gaussian beam generated by a spiral phase plate. It can also be generated by a Holographic Optical Element (HOE) containing the functions of the Spiral Phase Plate (SPP) and an axicon. However the HOBB's large focal depth reduces the intensity at each plane. In this paper, we propose a multifunctional Diffractive Optical Element (DOE) containing the functions of a SPP, axicon and a Fresnel Zone Lens (FZL) to generate higher efficiency higher order Bessel-like-beams with a reduced focal depth. The functions of a SPP and a FZL were combined by shifting the location of zones of FZL in a spiral fashion. The resulting element is combined with an axicon by modulo-2π phase addition technique. The final composite element contains the functions of SPP, FZL and axicon. The elements were designed with different topological charges and fabricated using electron beam direct writing. The elements were tested and the generation of a higher order Bessel-like-beams is confirmed. Besides, the elements also generated high quality donut beams at two planes equidistant from the focal plane of the FZL.

  8. Three-dimensional deep sub-diffraction optical beam lithography with 9 nm feature size.

    PubMed

    Gan, Zongsong; Cao, Yaoyu; Evans, Richard A; Gu, Min

    2013-01-01

    The current nanofabrication techniques including electron beam lithography provide fabrication resolution in the nanometre range. The major limitation of these techniques is their incapability of arbitrary three-dimensional nanofabrication. This has stimulated the rapid development of far-field three-dimensional optical beam lithography where a laser beam is focused for maskless direct writing. However, the diffraction nature of light is a barrier for achieving nanometre feature and resolution in optical beam lithography. Here we report on three-dimensional optical beam lithography with 9 nm feature size and 52 nm two-line resolution in a newly developed two-photon absorption resin with high mechanical strength. The revealed dependence of the feature size and the two-line resolution confirms that they can reach deep sub-diffraction scale but are limited by the mechanical strength of the new resin. Our result has paved the way towards portable three-dimensional maskless laser direct writing with resolution fully comparable to electron beam lithography.

  9. Optical waveguide beam splitters based on hybrid metal-dielectric-semiconductor nanostructures

    NASA Astrophysics Data System (ADS)

    Li, Yunyun; Liang, Junwu; Zhang, Qinglin; Zhou, Zidong; Li, Honglai; Fan, Xiaopeng; Wang, Xiaoxia; Fan, Peng; Yang, Yankun; Guo, Pengfei; Zhuang, Xiujuan; Zhu, Xiaoli; Liao, Lei; Pan, Anlian

    2015-11-01

    Miniature integration is desirable for the future photonics circuit. Low-dimensional semiconductor and metal nanostructures is the potential building blocks in compact photonic circuits for their unique electronic and optical properties. In this work, a hybrid metal-dielectric-semiconductor nanostructure is designed and fabricated to realizing a nano-scale optical waveguide beam splitter, which is constructed with the sandwiched structure of a single CdS nanoribbon/HfO2 thin film/Au nanodisk arrays. Micro-optical investigations reveal that the guided light outputting at the terminal end of the CdS ribbon is well separated into several light spots. Numerical simulations further demonstrate that the beam splitting mechanism is attributed to the strong electromagnetic coupling between the Au nanodisks and light guided in the nanoribbon. The number of the split beams (light spots) at the terminal end of the nanoribbon is mainly determined by the number of the Au nanodisk rows, as well as the distance of the blank region between the nanodisks array and the end of the CdS ribbon, owing to the interference between the split beams. These optical beam splitters may find potential applications in high-density integrated photonic circuits and systems.

  10. Development of Laser Beam Transmission Strategies for Future Ground-to-Space Optical Communications

    NASA Technical Reports Server (NTRS)

    Wilson, Keith E.; Kovalik, Joseph M.; Biswas, Abhijit; Roberts, William T.

    2007-01-01

    Optical communications is a key technology to meet the bandwidth expansion required in the global information grid. High bandwidth bi-directional links between sub-orbital platforms and ground and space terminals can provide a seamless interconnectivity for rapid return of critical data to analysts. The JPL Optical Communications Telescope Laboratory (OCTL) is located in Wrightwood California at an altitude of 2.2.km. This 200 sq-m facility houses a state-of- the-art 1-m telescope and is used to develop operational strategies for ground-to-space laser beam propagation that include safe beam transmission through navigable air space, adaptive optics correction and multi-beam scintillation mitigation, and line of sight optical attenuation monitoring. JPL has received authorization from international satellite owners to transmit laser beams to more than twenty retro-reflecting satellites. This paper presents recent progress in the development of these operational strategies tested by narrow laser beam transmissions from the OCTL to retro-reflecting satellites. We present experimental results and compare our measurements with predicted performance for a variety of atmospheric conditions.

  11. Generation and homodyne detection of continuous-variable entangled optical beams with a large wavelength difference

    SciTech Connect

    Guo Xiaomin; Xie Changde; Li Yongmin

    2011-08-15

    We present a scheme for generating and homodyne detecting of continuous-variable entanglement of bright optical beams with a large wavelength difference by utilizing an optical parametric oscillator (OPO) and an optical parametric amplifier (OPA) simultaneously. Entangled optical beams at 0.8 and 1.5 {mu}m are generated from the OPA; the seed beams injected in the OPA as well as the local oscillators at the two wavelengths needed for homodyne detection are provided by the OPO. The entangler is a ring resonator involving a second-order nonlinear crystal that is pumped from two opposite directions. In one direction the pump power is above the oscillation threshold and the optical nonlinear resonator operates as an OPO. In the other direction the pump power is below the threshold and it operates as a phase-sensitive frequency nondegenerate optical parametric amplifier. Our scheme combines the advantages of both OPO and OPA quantum optical devices and opens another avenue for preparation and homodyne detection of high quality bright entangled light with a large wavelength difference.

  12. Observation of optical transition radiation from electron beams generated by laser plasma accelerator

    NASA Astrophysics Data System (ADS)

    Lin, Chen; Nakamura, K.; Van, Tilborg J.; Gonsalves, A. J.; Sokollik, T.; Shiraishi, S.; Leemans, W. P.; Guo, Zhi-Yu

    2013-02-01

    Laser plasma accelerators (LPAs) have made great progress, achieving electron beam with energy up to 1 GeV from a centimeter scale capillary plasma waveguide. Here, we report the measurement of optical transition radiation (OTR) from the capillary-based LPA electron beams. Transition radiation images, produced by electrons passing through two separate foils (located at 2.3 m and 3.8 m away from the exit of the LPA) were recorded with a high resolution imaging system, respectively. Two magnetic quadrupole lenses were placed right after the capillary to focus and collimate the electron beams. Significant localized spikes appeared in the OTR images when the electron beam was focused by the magnetic quadrupole lenses, indicating the coherence of the radiation and the existence of ultrashort longitudinal structures inside the electron beam.

  13. Evidence for anomalous optical transition radiation linear polarization effects in beam-profile monitors

    NASA Astrophysics Data System (ADS)

    Lumpkin, A. H.; Johnson, A. S.; Ruan, J.; Thurman-Keup, R. M.; Yao, C.-Y.; Evtushenko, P.

    2013-10-01

    Investigations of the effects of optical transition radiation (OTR) polarization components on beam profiles are presented. The transverse profiles are examined using the OTR perpendicular and parallel polarization components with respect to the dimension of interest. We observed ˜15% projected profile size reductions with the perpendicularly polarized components on a 65-μm beam image size case at 14 MeV, a 150-μm beam image size at 4.5 GeV, and a 1100-μm beam image size at 7 GeV. These effects are all several times larger than expected (and anomalous in this sense) when compared to the standard OTR point-spread function calculations. We propose the time-averaged induced-current distribution which generates the OTR represents the actual beam size more faithfully with the perpendicular polarization component and recommend its routine use and subsequent deconvolution.

  14. A novel method for sub-micrometer transverse electron beam size measurements using optical transition radiation

    NASA Astrophysics Data System (ADS)

    Aryshev, A.; Boogert, S. T.; Howell, D.; Karataev, P.; Terunuma, N.; Urakawa, J.

    2010-06-01

    Optical Transition Radiation (OTR) appearing when a charged particle crosses a boundary between two media with different dielectric properties has widely been used as a tool for transverse profile measurements of charged particle beams in various facilities worldwide. The resolution of the monitor is defined by so-called Point Spread Function (PSF), source distribution generated by a single electron and projected by an optical system onto a screen. In this paper we represent the development of a novel sub-micrometre electron beam profile monitor based on the measurements of the PSF structure. The first experimental results are presented and future plans on the optimization of the monitor are discussed

  15. Interferometric adaptive optics for high-power laser beam correction in fast ignition experiments

    SciTech Connect

    Homoelle, D C; Baker, K L; Patel, P K; Utterback, E; Rushford, M C; Siders, C W; Barty, C J

    2009-10-22

    We present the design for a high-speed adaptive optics system that will be used to achieve the necessary laser pointing and beam-quality performance for initial fast-ignition coupling experiments. This design makes use of a 32 x 32 pixellated MEMS device as the adaptive optic and a two-channel interferometer as the wave-front sensor. We present results from a system testbed that demonstrates improvement of the Strehl ratio from 0.09 to 0.61 and stabilization of beam pointing from {approx}75{micro}rad to <2{micro}rad.

  16. Regular oscillations and random motion of glass microspheres levitated by a single optical beam in air

    DOE PAGES

    Moore, Jeremy; Martin, Leopoldo L.; Maayani, Shai; ...

    2016-02-03

    We experimentally reporton optical binding of many glass particles in air that levitate in a single optical beam. A diversity of particle sizes and shapes interact at long range in a single Gaussian beam. Our system dynamics span from oscillatory to random and dimensionality ranges from 1 to 3D. In conclusion, the low loss for the center of mass motion of the beads could allow this system to serve as a standard many body testbed, similar to what is done today with atoms, but at the mesoscopic scale.

  17. Plasmonic particles set into fast orbital motion by an optical vortex beam.

    PubMed

    Lehmuskero, Anni; Li, Yanming; Johansson, Peter; Käll, Mikael

    2014-02-24

    We optically trap plasmonic gold particles in two dimensions and set them into circular motion around the optical axis using a helically phased vortex laser beam. The orbiting frequency of the particles reaches 86 Hz, which corresponds to a particle velocity of the order 1 mm per second, for an incident laser power of a few tens of milliwatts. The experimentally determined orbiting frequencies are found to be well in line with the notion that the beam carries an orbital angular momentum of ħl per photon.

  18. Diagnostics of Electron Beams Based on Cherenkov Radiation in an Optical Fiber

    NASA Astrophysics Data System (ADS)

    Vukolov, A. V.; Novokshonov, A. I.; Potylitsyn, A. P.; Uglov, S. R.

    2017-02-01

    The use of an optical fiber in which Cherenkov radiation is generated instead of a metal wire for scanning a beam profile allows a compact and noise-proof device for diagnostics of charged particle beams in a wide energy range to be developed. Results of experimental investigation of the yield of Vavilov-Cherenkov radiation generated in optical fibers with thickness in the range from 0.125 to 1 mm by electrons with energy of 5.7 MeV are presented.

  19. Electro-optic harmonic conversion to switch a laser beam out of a cavity

    DOEpatents

    Haas, Roger A.; Henesian, Mark A.

    1987-01-01

    The invention is a switch to permit a laser beam to escape a laser cavity through the use of an externally applied electric field across a harmonic conversion crystal. Amplification takes place in the laser cavity, and then the laser beam is switched out by the laser light being harmonically converted with dichroic or polarization sensitive elements present to alter the optical path of the harmonically converted laser light. Modulation of the laser beam can also be accomplished by varying the external electric field.

  20. Overview of Nonintercepting Beam-Size Monitoring with Optical Diffraction Radiation

    SciTech Connect

    Lumpkin, Alex H.

    2010-11-04

    The initial demonstrations over the last several years of the use of optical diffraction radiation (ODR) as nonintercepting electron-beam-parameter monitors are reviewed. Developments in both far-field imaging and near-field imaging are addressed for ODR generated by a metal plane with a slit aperture, a single metal plane, and two-plane interferences. Polarization effects and sensitivities to beam size, divergence, and position will be discussed as well as a proposed path towards monitoring 10-micron beam sizes at 25 GeV.

  1. Overview of nonintercepting beam-size monitoring with optical diffraction radiation

    SciTech Connect

    Lumpkin, Alex H.; /Fermilab

    2010-08-01

    The initial demonstrations over the last several years of the use of optical diffraction radiation (ODR) as nonintercepting electron-beam-parameter monitors are reviewed. Developments in both far-field imaging and near-field imaging are addressed for ODR generated by a metal plane with a slit aperture, a single metal plane, and two-plane interferences. Polarization effects and sensitivities to beam size, divergence, and position will be discussed as well as a proposed path towards monitoring 10-micron beam sizes at 25 GeV.

  2. Vortex algebra by multiply cascaded four-wave mixing of femtosecond optical beams.

    PubMed

    Hansinger, Peter; Maleshkov, Georgi; Garanovich, Ivan L; Skryabin, Dmitry V; Neshev, Dragomir N; Dreischuh, Alexander; Paulus, Gerhard G

    2014-05-05

    Experiments performed with different vortex pump beams show for the first time the algebra of the vortex topological charge cascade, that evolves in the process of nonlinear wave mixing of optical vortex beams in Kerr media due to competition of four-wave mixing with self-and cross-phase modulation. This leads to the coherent generation of complex singular beams within a spectral bandwidth larger than 200nm. Our experimental results are in good agreement with frequency-domain numerical calculations that describe the newly generated spectral satellites.

  3. An optical system to transform the output beam of a quantum cascade laser to be uniform

    NASA Astrophysics Data System (ADS)

    Jacobson, Jordan M.

    Quantum cascade lasers (QCLs) are a candidate for calibration sources in space-based remote sensing applications. However, the output beam from a QCL has some characteris- tics that are undesirable in a calibration source. The output beam from a QCL is polarized, both temporally and spatially coherent, and has a non-uniform bivariate Gaussian prole. These characteristics need to be mitigated before QCLs can be used as calibration sources. This study presents the design and implementation of an optical system that manipulates the output beam from a QCL so that it is spatially and angularly uniform with reduced coherence and polarization. (85 pages).

  4. Optical-beam wavefront control based on the atmospheric backscatter signal

    SciTech Connect

    Banakh, V A; Razenkov, I A; Rostov, A P; Tsvyk, R Sh; Zhmylevskii, V V; Ignatiev, A B; Morozov, V V

    2015-02-28

    The feasibility of compensating for aberrations of the optical-beam initial wavefront by aperture sounding, based on the atmospheric backscatter signal from an additional laser source with a different wavelength, is experimentally studied. It is shown that the adaptive system based on this principle makes it possible to compensate for distortions of the initial beam wavefront on a surface path in atmosphere. Specifically, the beam divergence decreases, while the level of the detected mean backscatter power from the additional laser source increases. (light scattering)

  5. Optical beam focusing by a single subwavelength metal slit surrounded by chirped dielectric surface gratings

    SciTech Connect

    Kim, Seyoon; Lim, Yongjun; Kim, Hwi; Park, Junghyun; Lee, Byoungho

    2008-01-07

    A method for optical beam focusing by a single subwavelength metal slit surrounded by surface gratings is proposed. In our proposed method, the period of each surface grating is chirped so that the radiation fields of surface plasmon polaritons can be controlled to make a beam spot at the desired focal length. Through our proposed method, it is numerically shown that we can make a beam spot which is located at the several times of wavelength distance from the slit, and its focal length can be controlled.

  6. Application of Electron Beams in Space for Energy Storage and Optical Beam Generation,

    DTIC Science & Technology

    1978-04-01

    MIRROR -DRIFT __ SPACE BUNCHER OUTPUT RADIATION Fig. 6-Optical klystron I/ // CATCHER MAGNET - / PAIR OF CORNER MAGNETSI ~FORM AN ACHROMATIC SERVCO.Rl I...optical link will be unable to penetrate heavy cloud formations and will thus present availability problems in most regions of the world. CONCLUDING

  7. Electron beam optics and trajectory control in the Fermi free electron laser delivery system

    NASA Astrophysics Data System (ADS)

    di Mitri, S.; Cornacchia, M.; Scafuri, C.; Sjöström, M.

    2012-01-01

    Electron beam optics (particle betatron motion) and trajectory (centroid secular motion) in the FERMI@Elettra free electron laser (FEL) are modeled and experimentally controlled by means of the elegant particle tracking code. This powerful tool, well known to the accelerator community, is here for the first time fully integrated into the Tango-server based high level software of an FEL facility, thus ensuring optimal charge transport efficiency and superposition of the beam Twiss parameters to the design optics. The software environment, the experimental results collected during the commissioning of FERMI@Elettra, and the comparison with the model are described. As a result, a matching of the beam optics to the design values is accomplished and quantified in terms of the betatron mismatch parameter with relative accuracy down to the 10-3 level. The beam optics control allows accurate energy spread measurements with sub-keV accuracy in dedicated dispersive lines. Trajectory correction and feedback is achieved to a 5μm level with the implementation of theoretical response matrices. In place of the empirical ones, they speed up the process of trajectory control when the machine optics is changed, avoid particle losses that may occur during the on-line computation of experimental matrices, and confirm a good agreement of the experimental magnetic lattice with the model.

  8. Research on the effect of coherent beam combination based on array of liquid crystal optical phased arrays

    NASA Astrophysics Data System (ADS)

    Yang, Zhenming; Kong, Lingjiang; Xiao, Feng; Chen, Jian

    2014-12-01

    On the basis of Coherent Beam Combination(CBC) based on Array of Liquid Crystal Optical Phased Arrays(LCOPA array), two major contributions are made in this article. Firstly, grating lobes and side lobes of combined beam are analyzed. Furthermore, according to interference theory the methods to suppress grating lobes and side lobes are put forward. Secondly, a new beam quality factor Q(θ0) is proposed to evaluate the beam quality of combined beam and several influence factors are discussed. These analysis results help to obtain combined beam with better beam quality.

  9. Software for a Multi-beam Optical Stress Sensor

    SciTech Connect

    Hunter, John A.; Hearne, Sean J.

    2000-04-19

    This software program tracks multiple laser beam spots reflected from a substrate which is changing its shape in response to changes in environment or changes in its physical state. The geometry of the laser, substrate, camera, and substrate parameters result in a final measurement of the stress-thickness product that would bend the substrate to its final curvature. A typical example is thin film growth.

  10. Acoustic field structure simulation in quasi-collinear acousto-optic cells with ultrasound beam reflection.

    PubMed

    Mantsevich, S N; Molchanov, V Ya; Yushkov, K B; Khorkin, V S; Kupreychik, M I

    2017-04-02

    Ultrasound wave reflection from one of the crystal faces is the convenient way to arouse the acoustic beam with a desired propagation direction in acousto-optic cells with collinear and quasi-collinear interaction geometries. The reflection process effects on the ultrasound field amplitude and phase structure. The method to simulate the reflected finite ultrasound beam structure in the case of acoustically anisotropic media is presented in this paper. The investigation is carried on the example of two quasi-collinear acousto-optic cells fabricated on the base of tellurium dioxide crystal. The cells have special geometry that allows to obtain extremely long acousto-optic interaction length and to achieve unprecedented spectral resolution. The influence of reflection process in the acousto-optic diffraction characteristics was also examined.

  11. Wave-optics description of self-healing mechanism in Bessel beams.

    PubMed

    Aiello, Andrea; Agarwal, Girish S

    2014-12-15

    Bessel beams' great importance in optics lies in that these propagate without spreading and can reconstruct themselves behind an obstruction placed across their path. However, a rigorous wave-optics explanation of the latter property is missing. In this work, we study the reconstruction mechanism by means of a wave-optics description. We obtain expressions for the minimum distance beyond the obstruction at which the beam reconstructs itself, which are in close agreement with the traditional one determined from geometrical optics. Our results show that the physics underlying the self-healing mechanism can be entirely explained in terms of the propagation of plane waves with radial wave vectors lying on a ring.

  12. Controlled modulation of laser beam and dynamic patterning of colloidal particles using optical tweezers

    NASA Astrophysics Data System (ADS)

    Singh, Brijesh Kumar; Singh Mehta, Dalip; Kumar, Ranjeet; Senthilkumaran, Paramasivam

    2016-02-01

    We present controlled generation of complex-structured beam profiles using diffractive optical element and demonstrate multiple dynamic trapping of colloidal particles. The phase element is programmed to generate various tailored optical fields having structures, similar to that of number three, spiral, and circle but in a tractable manner. Thus, the generated spatially tailored optical fields are confined to focal volume in optical tweezers. This enabled real-time trapping of multiple microscopic objects whereby its transverse organization was controlled in a dynamic manner from one structure to another with the help of spatial light modulator. Such a controlled beam shaping finds potential applications in biophotonics, super resolution imaging, and measurement of biophysical parameters, cell sorting, and micro-manipulation of colloidal particles.

  13. Scintillation and beam-wander analysis in an optical ground station-satellite uplink.

    PubMed

    Dios, Federico; Rubio, Juan Antonio; Rodrfguez, Alejandro; Comerón, Adolfo

    2004-07-01

    In an optical communication link between an optical ground station and a geostationary satellite the main problems appear in the uplink and are due to beam wander and to scintillation. Reliable methods for modeling both effects simultaneously are needed to provide an accurate tool with which the robustness of the communication channel can be tested. Numerical tools, especially the split-step method (also referred to as the fast-Fourier-transform beam propagation method), have demonstrated their ability to deal with problems of optical propagation during atmospheric turbulence. However, obtaining statistically significant results with this technique is computationally intensive. We present an analytical-numerical hybrid technique that provides good information on the variance in optical irradiance with an important saving of time and computational resources.

  14. Adaptive control of modal properties of optical beams using photothermal effects.

    PubMed

    Arain, Muzammil A; Korth, William Z; Williams, Luke F; Martin, Rodica M; Mueller, Guido; Tanner, D B; Reitze, David H

    2010-02-01

    We present an experimental demonstration of adaptive control of modal properties of optical beams. The control is achieved via heat-induced photothermal actuation of transmissive optical elements. We apply the heat using four electrical heaters in thermal contact with the element. The system is capable of controlling both symmetrical and astigmatic aberrations providing a powerful means for in situ correction and control of thermal aberrations in high power laser systems. We demonstrate a tunable lens with a focusing power varying from minus infinity to -10 m along two axes using SF57 optical glass. Applications of the proposed system include laser material processing, thermal compensation of high laser power radiation, and optical beam steering.

  15. Data and Analysis from a Time-Resolved Tomographic Optical Beam Diagnostic

    SciTech Connect

    Daniel K. Frayer, Douglas Johnson, Carl Ekdahl

    2010-05-02

    An optical tomographic diagnostic instrument developed for the acquisition of high-speed time-resolved images has been fielded at the Dual-Axis Radiographic Hydrodynamic Test (DARHT) Facility at Los Alamos National Laboratory. The instrument was developed for the creation of time histories of electron-beam cross section through the collection of Cerenkov light. Four optical lines of sight optically collapse an image and relay projections via an optical fiber relay to recording instruments; a tomographic reconstruction algorithm creates the time history. Because the instrument may be operated in an adverse environment, it may be operated, adjusted, and calibrated remotely. The instrument was operated over the course of various activities during and after DARHT commissioning, and tomographic reconstructions reported verifiable beam characteristics. Results from the collected data and reconstructions and analysis of the data are discussed.

  16. Wave optics simulation of spatially partially coherent beams: Applications to free space laser communications

    NASA Astrophysics Data System (ADS)

    Xiao, Xifeng

    One of the main drawbacks that prevent the extensive application of free space laser communications is the atmospheric turbulence through which the beam must propagate. For the past four decades, much attention has been devoted to finding different methods to overcome this difficulty. A partially coherent beam (PCB) has been recognized as an effective approach to improve the performance of an atmospheric link. It has been examined carefully with most analyses considering the Gaussian Schell-model (GSM) beam. However, practical PCBs may not follow GSM theory and are better examined through some numerical simulation approach such as a wave optics simulation. Consequently, an approach for modeling the spatially PCB in wave optics simulation is presented here. The approach involves the application of a sequence of random phase screens to an initial beam field and the summation of the intensity results after propagation. The relationship between the screen parameters and the spatial coherence function for the beam is developed and the approach is verified by comparing results with analytic formulations for a Gaussian Schell-model (GSM) beam. A variety of simulation studies were performed for this dissertation. The propagation through turbulence of a coherent beam and a particular version of a PCB, a pseudo-partially coherent beam (PPCB), is analyzed. The beam is created with a sequence of several Gaussian random phase screens for each atmospheric realization. The average intensity profiles, the scintillation index and aperture averaging factor for a horizontal propagation scenario are examined. Comparisons between these results and their corresponding analytic results for the well-known GSM beam are also made. Cumulative probability density functions for the received irradiance are initially investigated. Following the general simulation investigations, a performance metric is proposed as a general measure for optimizing the transverse coherence length of a partial

  17. Phase space tomography reconstruction of the Wigner distribution for optical beams separable in Cartesian coordinates.

    PubMed

    Cámara, Alejandro; Alieva, Tatiana; Rodrigo, José A; Calvo, María L

    2009-06-01

    We propose a simple approach for the phase space tomography reconstruction of the Wigner distribution of paraxial optical beams separable in Cartesian coordinates. It is based on the measurements of the antisymmetric fractional Fourier transform power spectra, which can be taken using a flexible optical setup consisting of four cylindrical lenses. The numerical simulations and the experimental results clearly demonstrate the feasibility of the proposed scheme.

  18. Neural nets for aligning optical components in harsh environments: Beam smoothing spatial filter as an example

    NASA Technical Reports Server (NTRS)

    Decker, Arthur J.; Krasowski, Michael J.

    1991-01-01

    The goal is to develop an approach to automating the alignment and adjustment of optical measurement, visualization, inspection, and control systems. Classical controls, expert systems, and neural networks are three approaches to automating the alignment of an optical system. Neural networks were chosen for this project and the judgements that led to this decision are presented. Neural networks were used to automate the alignment of the ubiquitous laser-beam-smoothing spatial filter. The results and future plans of the project are presented.

  19. Ultrafast Radiation Detection by Modulation of an Optical Probe Beam

    SciTech Connect

    Vernon, S P; Lowry, M E

    2006-02-22

    We describe a new class of radiation sensor that utilizes optical interferometry to measure radiation-induced changes in the optical refractive index of a semiconductor sensor medium. Radiation absorption in the sensor material produces a transient, non-equilibrium, electron-hole pair distribution that locally modifies the complex, optical refractive index of the sensor medium. Changes in the real (imaginary) part of the local refractive index produce a differential phase shift (absorption) of an optical probe used to interrogate the sensor material. In contrast to conventional radiation detectors where signal levels are proportional to the incident energy, signal levels in these optical sensors are proportional to the incident radiation energy flux. This allows for reduction of the sensor form factor with no degradation in detection sensitivity. Furthermore, since the radiation induced, non-equilibrium electron-hole pair distribution is effectively measured ''in place'' there is no requirement to spatially separate and collect the generated charges; consequently, the sensor risetime is of the order of the hot-electron thermalization time {le} 10 fs and the duration of the index perturbation is determined by the carrier recombination time which is of order {approx} 600 fs in, direct-bandgap semiconductors, with a high density of recombination defects; consequently, the optical sensors can be engineered with sub-ps temporal response. A series of detectors were designed, and incorporated into Mach Zehnder and Fabry-Perot interferometer-based detection systems: proof of concept, lower detection sensitivity, Mach-Zehnder detectors were characterized at beamline 6.3 at SSRL; three generations of high sensitivity single element and imaging Fabry-Perot detectors were measured at the LLNL Europa facility. Our results indicate that this technology can be used to provide x-ray detectors and x-ray imaging systems with single x-ray sensitivity and S/N {approx} 30 at x

  20. Development of dual-probe atomic force microscopy system using optical beam deflection sensors with obliquely incident laser beams.

    PubMed

    Tsunemi, Eika; Kobayashi, Kei; Matsushige, Kazumi; Yamada, Hirofumi

    2011-03-01

    We developed a dual-probe (DP) atomic force microscopy (AFM) system that has two independently controlled probes. The deflection of each cantilever is measured by the optical beam deflection (OBD) method. In order to keep a large space over the two probes for an objective lens with a large numerical aperture, we employed the OBD sensors with obliquely incident laser beams. In this paper, we describe the details of our developed DP-AFM system, including analysis of the sensitivity of the OBD sensor for detection of the cantilever deflection. We also describe a method to eliminate the crosstalk caused by the vertical translation of the cantilever. In addition, we demonstrate simultaneous topographic imaging of a test sample by the two probes and surface potential measurement on an α-sexithiophene (α-6T) thin film by one probe while electrical charges were injected by the other probe.

  1. Development of dual-probe atomic force microscopy system using optical beam deflection sensors with obliquely incident laser beams

    NASA Astrophysics Data System (ADS)

    Tsunemi, Eika; Kobayashi, Kei; Matsushige, Kazumi; Yamada, Hirofumi

    2011-03-01

    We developed a dual-probe (DP) atomic force microscopy (AFM) system that has two independently controlled probes. The deflection of each cantilever is measured by the optical beam deflection (OBD) method. In order to keep a large space over the two probes for an objective lens with a large numerical aperture, we employed the OBD sensors with obliquely incident laser beams. In this paper, we describe the details of our developed DP-AFM system, including analysis of the sensitivity of the OBD sensor for detection of the cantilever deflection. We also describe a method to eliminate the crosstalk caused by the vertical translation of the cantilever. In addition, we demonstrate simultaneous topographic imaging of a test sample by the two probes and surface potential measurement on an α-sexithiophene (α-6T) thin film by one probe while electrical charges were injected by the other probe.

  2. SU-E-T-610: Phosphor-Based Fiber Optic Probes for Proton Beam Characterization

    SciTech Connect

    Darafsheh, A; Soldner, A; Liu, H; Kassaee, A; Zhu, T; Finlay, J

    2015-06-15

    Purpose: To investigate feasibility of using fiber optics probes with rare-earth-based phosphor tips for proton beam radiation dosimetry. We designed and fabricated a fiber probe with submillimeter resolution (<0.5 mm3) based on TbF3 phosphors and evaluated its performance for measurement of proton beam including profiles and range. Methods: The fiber optic probe with TbF3 phosphor tip, embedded in tissue-mimicking phantoms was irradiated with double scattering proton beam with energy of 180 MeV. Luminescence spectroscopy was performed by a CCD-coupled spectrograph to analyze the emission spectra of the fiber tip. In order to measure the spatial beam profile and percentage depth dose, we used singular value decomposition method to spectrally separate the phosphors ionoluminescence signal from the background Cerenkov radiation signal. Results: The spectra of the TbF3 fiber probe showed characteristic ionoluminescence emission peaks at 489, 542, 586, and 620 nm. By using singular value decomposition we found the contribution of the ionoluminescence signal to measure the percentage depth dose in phantoms and compared that with measurements performed with ion chamber. We observed quenching effect at the spread out Bragg peak region, manifested as under-responding of the signal, due to the high LET of the beam. However, the beam profiles were not dramatically affected by the quenching effect. Conclusion: We have evaluated the performance of a fiber optic probe with submillimeter resolution for proton beam dosimetry. We demonstrated feasibility of spectral separation of the Cerenkov radiation from the collected signal. Such fiber probes can be used for measurements of proton beams profile and range. The experimental apparatus and spectroscopy method developed in this work provide a robust platform for characterization of proton-irradiated nanophosphor particles for ultralow fluence photodynamic therapy or molecular imaging applications.

  3. Dual focused coherent beams for three-dimensional optical trapping and continuous rotation of metallic nanostructures

    PubMed Central

    Xu, Xiaohao; Cheng, Chang; Zhang, Yao; Lei, Hongxiang; Li, Baojun

    2016-01-01

    Metallic nanoparticles and nanowires are extremely important for nanoscience and nanotechnology. Techniques to optically trap and rotate metallic nanostructures can enable their potential applications. However, because of the destabilizing effects of optical radiation pressure, the optical trapping of large metallic particles in three dimensions is challenging. Additionally, the photothermal issues associated with optical rotation of metallic nanowires have far prevented their practical applications. Here, we utilize dual focused coherent beams to realize three-dimensional (3D) optical trapping of large silver particles. Continuous rotation of silver nanowires with frequencies measured in several hertz is also demonstrated based on interference-induced optical vortices with very low local light intensity. The experiments are interpreted by numerical simulations and calculations. PMID:27386838

  4. Dual focused coherent beams for three-dimensional optical trapping and continuous rotation of metallic nanostructures

    NASA Astrophysics Data System (ADS)

    Xu, Xiaohao; Cheng, Chang; Zhang, Yao; Lei, Hongxiang; Li, Baojun

    2016-07-01

    Metallic nanoparticles and nanowires are extremely important for nanoscience and nanotechnology. Techniques to optically trap and rotate metallic nanostructures can enable their potential applications. However, because of the destabilizing effects of optical radiation pressure, the optical trapping of large metallic particles in three dimensions is challenging. Additionally, the photothermal issues associated with optical rotation of metallic nanowires have far prevented their practical applications. Here, we utilize dual focused coherent beams to realize three-dimensional (3D) optical trapping of large silver particles. Continuous rotation of silver nanowires with frequencies measured in several hertz is also demonstrated based on interference-induced optical vortices with very low local light intensity. The experiments are interpreted by numerical simulations and calculations.

  5. Measurements of the optical emission produced during the laboratory beam plasma discharge

    NASA Technical Reports Server (NTRS)

    Hallinan, T. J.; Leinbach, H.; Mantjoukis, G.; Bernstein, W.

    1984-01-01

    Optical observations of a beam-plasma discharge (BPD) in the laboratory showed that the discharge remained confined to a diameter little more than double that of the beam for injection parallel to the magnetic field and approximately equal to that of the beam for injection at large pitch angles. The diameter was independent of beam current but varied linearly with beam velocity and inversely with magnetic field strength. The ionization rate inferred from the total emission of 3914 A, integrated over the radial extent of the beam, was proportional to the excess beam current above that requied for BPD ignition. The proportionality constant ( 12 + or - 2) x 10 to the 14th ions/cm s A was valid over a wide range of pressure and of magnetic field strength. Power loss to ionization in a 20 m path was estimated at up to 4 percent of the beam power. Evidence is presented for effective confinement of suprathermal electrons (parallel to B) by some unidentified process other than electrostatic confinement.

  6. Numerical investigation of output beam quality in efficient broadband optical parametric chirped pulse amplification

    NASA Astrophysics Data System (ADS)

    Liu, Xiao-Di; Xu, Lu; Liang, Xiao-Yan

    2017-01-01

    We theoretically analyzed output beam quality of broad bandwidth non-collinear optical parametric chirped pulse amplification (NOPCPA) in LiB3O5 (LBO) centered at 800 nm. With a three-dimensional numerical model, the influence of the pump intensity, pump and signal spatial modulations, and the walk-off effect on the OPCPA output beam quality are presented, together with conversion efficiency and the gain spectrum. The pump modulation is a dominant factor that affects the output beam quality. Comparatively, the influence of signal modulation is insignificant. For a low-energy system with small beam sizes, walk-off effect has to be considered. Pump modulation and walk-off effect lead to asymmetric output beam profile with increased modulation. A special pump modulation type is found to optimize output beam quality and efficiency. For a high-energy system with large beam sizes, the walk-off effect can be neglected, certain back conversion is beneficial to reduce the output modulation. A trade-off must be made between the output beam quality and the conversion efficiency, especially when the pump modulation is large since. A relatively high conversion efficiency and a low output modulation are both achievable by controlling the pump modulation and intensity.

  7. Optical guiding of laser beam in nonuniform plasma

    NASA Astrophysics Data System (ADS)

    Singh Gill, Tarsem

    2000-11-01

    A plasma channel produced by a short ionising laser pulse is axially nonuniform resulting from the self-defocusing. Through such preformed plasma channel, when a delayed pulse propagates, the phenomena of diffraction, refraction and self-phase modulation come into play. We have solved the nonlinear parabolic partial differential equation governing the propagation characteristics for an approximate analytical solution using variational approach. Results are compared with the theoretical model of Liu and Tripathi ( Phys. Plasmas, 1, 3100 (1994)) based on paraxial ray approximation. Particular emphasis is on both beam width and longitudinal phase delay which are crucial to many applications.}

  8. Turbid media optical properties derived from the characteristics of propagating laser radiation beams

    NASA Astrophysics Data System (ADS)

    Gurdev, Ljuan; Dreischuh, Tanja; Vankov, Orlin; Bliznakova, Irina; Avramov, Lachezar; Stoyanov, Dimitar

    2014-06-01

    The possibility is studied to develop a straightforward analytical approach to the determination of the optical properties of liquid turbid media having forward-peaked scattering indicatrices. The approach is based on investigating the in-depth behavior of the radius and the axial intensity of a laser radiation beam propagating through the turbid medium. Based on the small-angle approximation, the detected forward-propagating light power spatial distribution, at relatively small or large optical depths along the beam axis, is obtained asymptotically in analytical form allowing one to derive relatively simple expressions of the extinction, reduced-scattering and absorption coefficients and the anisotropy factor of the medium through the characteristics of the propagating light beam. Preliminary experiments have also been performed, using Intralipid dilutions of different relatively low concentrations and measuring the cross-sectional radial distribution of the detected light power at different depths along the beam axis. The corresponding on-axis detected light power profiles have been measured independently as well. The experimental results are consistent with the analytical expressions obtained that allow one to estimate the optical coefficients and the anisotropy factor of the investigated media on the basis of the measured beam characteristics. The values obtained are near those predicted by other researchers.

  9. Uniformity of reshaped beam by diffractive optical elements with light-emitted diode illumination

    NASA Astrophysics Data System (ADS)

    Chen, Mengzhu; Gu, Huarong; Wang, Qixia; Tan, Qiaofeng

    2015-10-01

    Due to its low energy consumption, high efficiency and fast switching speed, light-emitted diode (LED) has been used as a new light source in optical wireless communication. To ensure uniform lighting and signal-to-noise ratio (SNR) during the data transmission, diffractive optical elements (DOEs) can be employed as optical antennas. Different from laser, LED has a low temporal and spatial coherence. And its impacts upon the far-field diffraction patterns of DOEs remain unclear. Thus the mathematical models of far-field diffraction intensity for LED with a spectral bandwidth and source size are first derived in this paper. Then the relation between source size and uniformity of top-hat beam profile for LEDs either considering the spectral bandwidth or not are simulated. The results indicate that when the size of LED is much smaller than that of reshaped beam, the uniformity of reshaped beam obtained by light source with a spectral bandwidth is significantly better than that by a monochromatic light. However, once the size is larger than a certain threshold value, the uniformity of reshaped beam of two LED models are almost the same, and the influence introduced by spectral bandwidth can be ignored. Finally the reshaped beam profiles are measured by CCD camera when the areas of LED are 0.5×0.5mm2 and 1×1mm2. And the experimental results agree with the simulations.

  10. Beam evolutions of solitons in strongly nonlocal media with fading optical lattices

    NASA Astrophysics Data System (ADS)

    Dai, Zhi-Ping; Lu, Shi-Zhuan; You, Kai-Ming

    2013-01-01

    We address the impact of imprinted fading optical lattices on the beam evolution of solitons in strongly nonlocal nonlinear media. The results show that the width of the soliton experiences a change with the increasing propagation distance, the critical power for the soliton varies with the lattice fading away, and the soliton breathing is affected by the initial lattice depth and the nonlocality degree.

  11. Synthetic diagnostic for the beam emission spectroscopy diagnostic using a full optical integration

    NASA Astrophysics Data System (ADS)

    Hausammann, L.; Churchill, R. M.; Shi, L.

    2017-02-01

    The beam emission spectroscopy (BES) diagnostic is used to measure fluctuations of electron density in the edge and core of fusion plasmas, and is a key in understanding turbulence in a plasma reactor. A synthetic BES diagnostic for the turbulence simulation code XGC1 has been developed using a realistic neutral beam model and an optical system easily adaptable to different kinds of tokamaks. The beam is modeled using multiple beam energy components, each one with a fraction of the total energy and their own mass and energy (mono-energetic components). The optical system consists of a lens focusing a bundle of optical fibers and resulting in a 2D measurement. The synthetic diagnostic gives similar correlation functions and behaviour of the turbulences than the usual methods that do not take into account the full 3D optical effects. The results, based on a simulation of XGC1, contain an analysis of the correlation (in space and time), a comparison of different approximations possible and their importance in accurately modeling the BES diagnostic.

  12. Application of Cerenkov radiation generated in plastic optical fibers for therapeutic photon beam dosimetry.

    PubMed

    Jang, Kyoung Won; Yagi, Takahiro; Pyeon, Cheol Ho; Yoo, Wook Jae; Shin, Sang Hun; Jeong, Chiyoung; Min, Byung Jun; Shin, Dongho; Misawa, Tsuyoshi; Lee, Bongsoo

    2013-02-01

    A Cerenkov fiber-optic dosimeter (CFOD) is fabricated using plastic optical fibers to measure Cerenkov radiation induced by a therapeutic photon beam. We measured the Cerenkov radiation generated in optical fibers in various irradiation conditions to evaluate the usability of Cerenkov radiation for a photon beam therapy dosimetry. As a results, the spectral peak of Cerenkov radiation was measured at a wavelength of 515 nm, and the intensity of Cerenkov radiation increased linearly with increasing irradiated length of the optical fiber. Also, the intensity peak of Cerenkov radiation was measured in the irradiation angle range of 30 to 40 deg. In the results of Monte Carlo N-particle transport code simulations, the relationship between fluxes of electrons over Cerenkov threshold energy and energy deposition of a 6 MV photon beam had a nearly linear trend. Finally, percentage depth doses for the 6 MV photon beam could be obtained using the CFOD and the results were compared with those of an ionization chamber. Here, the mean dose difference was about 0.6%. It is anticipated that the novel and simple CFOD can be effectively used for measuring depth doses in radiotherapy dosimetry.

  13. Imaging of high-energy electron beam profile with optical diffraction radiation

    NASA Astrophysics Data System (ADS)

    Xiang, Dao; Huang, Wen-Hui; Lin, Yu-Zheng

    2007-06-01

    Optical transition radiation (OTR) has been widely used in electron beam profile imaging. Optical diffraction radiation (ODR) has recently been used to measure the electron beam’s transverse size with the angular distribution. Because of the close relationship between OTR and ODR, it is natural to ask whether ODR could be used to image the beam profile as is done with OTR. In this paper, the image formation process is investigated as a two-dimensional (2D) convolution. The image formed with ODR as a single electron passes through a circular aperture, through a rectangular slit, and beneath a semi-infinite plane is studied from first principle and taken to be the point spread function (PSF) of the imaging system. It is found that, unlike the OTR case, the PSF of ODR is space variant and largely depends on the shape of the ODR target. With this characteristic, the beam image formed with ODR differs greatly from the real beam profile, and the deconvolution process is generally needed in order to retrieve the real beam distribution from the ODR image. The possibility of using an image formed with ODR from a rectangular slit and a semi-infinite plane to determine beam profile in the direction parallel to the edge of the slit or plane and monitoring the beam’s position are estimated. The theoretical prediction is compared to recently reported experimental results and a qualitative agreement is achieved.

  14. Ion beam figuring approach for thermally sensitive space optics.

    PubMed

    Yin, Xiaolin; Deng, Weijie; Tang, Wa; Zhang, Binzhi; Xue, Donglin; Zhang, Feng; Zhang, Xuejun

    2016-10-01

    During the ion beam figuring (IBF) of a space mirror, thermal radiation of the neutral filament and particle collisions will heat the mirror. The adhesive layer used to bond the metal parts and the mirror is very sensitive to temperature rise. When the temperature exceeds the designed value, the mirror surface shape will change markedly because of the thermal deformation and stress release of the adhesive layer, thereby reducing the IBF accuracy. To suppress the thermal effect, we analyzed the heat generation mechanism. By using thermal radiation theory, we established a thermal radiation model of the neutral filament. Additionally, we acquired a surface-type Gaussian heat source model of the ion beam sputtering based on the removal function and Faraday scan result. Using the finite-element-method software ABAQUS, we developed a method that can simulate the thermal effect of the IBF for the full path and all dwell times. Based on the thermal model, which was experimentally confirmed, we simulated the thermal effects for a 675  mm×374  mm rectangular SiC space mirror. By optimizing the dwell time distribution, the peak temperature value of the adhesive layer during the figuring process was reduced under the designed value. After one round of figuring, the RMS value of the surface error changed from 0.094 to 0.015λ (λ=632.8  nm), which proved the effectiveness of the thermal analysis and suppression method.

  15. Experimental validation of ultra-thin metalenses for N-beam emissions based on transformation optics

    SciTech Connect

    Zhang, Kuang; Ding, Xumin; Meng, Fanrong; Wu, Qun; Wo, Deliang

    2016-02-01

    A general design of metalenses for N-beam emissions is proposed based on transformation optics. A linear mapping function is adopted to achieve the homogeneous characterization of the transforming medium, which is therefore easy to be achieved compared with previous designs limited by inhomogeneity based on transformation optics. To verify the theoretical design, a four-beam antenna constructed with ultrathin, homogenous, and uniaxial anisotropic metalens is designed, fabricated, and measured. It is shown that the realized gain of the four-beam antenna is increased by 6 dB compared with the single dipole source, while working frequency and relative bandwidth are kept unchanged. The measured far-field pattern verifies theoretical design procedure.

  16. Thermomagnetic recording and magneto-optic playback system having constant intensity laser beam control

    NASA Technical Reports Server (NTRS)

    Lewicki, G. W.; Guisinger, J. E. (Inventor)

    1973-01-01

    A system is developed for maintaining the intensity of a laser beam at a constant level in a thermomagnetic recording and magneto-optic playback system in which an isotropic film is heated along a continuous path by the laser beam for recording. As each successive area of the path is heated locally to the vicinity of its Curie point in the presence of a controlled magnetic field, a magneto-optic density is produced proportional to the amplitude of the controlled magnetic field. To play back the recorded signal, the intensity of the laser beam is reduced and a Faraday or Kerr effect analyzer is used, with a photodetector, as a transducer for producing an output signal.

  17. High-voltage scanning ion microscope: Beam optics and design

    NASA Astrophysics Data System (ADS)

    Magilin, D.; Ponomarev, A.; Rebrov, V.; Ponomarov, A.

    2015-05-01

    This article is devoted to the conceptual design of a compact high-voltage scanning ion microscope (HVSIM). In an HVSIM design, the ion optical system is based on a high-brightness ion source. Specifically, the ion optical system is divided into two components: an ion injector and a probe-forming system (PFS) that consists of an accelerating tube and a multiplet of quadrupole lenses. The crossover is formed and controlled by the injector, which acts as an object collimator, and is focused on the image plane by the PFS. The ion microprobe has a size of 0.1 μm and an energy of 2 MeV. When the influence of the chromatic and third-order aberrations is theoretically taken into account, the HVSIM forms an ion microprobe.

  18. Electro-optic techniques in electron beam diagnostics

    SciTech Connect

    van Tilborg, Jeroen; Toth, Csaba; Matlis, Nicholas; Plateau, Guillaume; Leemans, Wim

    2011-06-17

    Electron accelerators such as laser wakefield accelerators, linear accelerators driving free electron lasers, or femto-sliced synchrotrons, are capable of producing femtosecond-long electron bunches. Single-shot characterization of the temporal charge profile is crucial for operation, optimization, and application of such accelerators. A variety of electro-optic sampling (EOS) techniques exists for the temporal analysis. In EOS, the field profile from the electron bunch (or the field profile from its coherent radiation) will be transferred onto a laser pulse co-propagating through an electro-optic crystal. This paper will address the most common EOS schemes and will list their advantages and limitations. Strong points that all techniques share are the ultra-short time resolution (tens of femtoseconds) and the single-shot capabilities. Besides introducing the theory behind EOS, data from various research groups is presented for each technique.

  19. Electronically controlled optical beam-steering by an active phased array of metallic nanoantennas.

    PubMed

    DeRose, C T; Kekatpure, R D; Trotter, D C; Starbuck, A; Wendt, J R; Yaacobi, A; Watts, M R; Chettiar, U; Engheta, N; Davids, P S

    2013-02-25

    An optical phased array of nanoantenna fabricated in a CMOS compatible silicon photonics process is presented. The optical phased array is fed by low loss silicon waveguides with integrated ohmic thermo-optic phase shifters capable of 2π phase shift with ∼ 15 mW of applied electrical power. By controlling the electrical power to the individual integrated phase shifters fixed wavelength steering of the beam emitted normal to the surface of the wafer of 8° is demonstrated for 1 × 8 phased arrays with periods of both 6 and 9 μm.

  20. Studies of Non-Linear Optical Effects for Agile Beam Steering

    DTIC Science & Technology

    1993-11-01

    corresponded to: 1. An initial demonstration of the nonlinear optical enhancement effect in an off-the-shelf AO beam deflector . 2 . A demonstration of an...by showing an intensity-dependentertun• acousto - optic diffraction efficiency in a Tel) 2 Bragg ceUl un-ertures.der high-power pulsed illumination. The...proportional refractive-index d variation through the medium’s photoelastic response, the - d 2 (Ap)/dt- + v2V2 ( p) + ( 2 */0 2L,. - V(Ap) incident optical

  1. Collimation of a thulium atomic beam by two-dimensional optical molasses

    SciTech Connect

    Sukachev, D D; Kalganova, E S; Sokolov, A V; Savchenkov, A V; Vishnyakova, G A; Golovizin, A A; Akimov, A V; Kolachevsky, Nikolai N; Sorokin, Vadim N

    2013-04-30

    The number of laser cooled and trapped thulium atoms in a magneto-optical trap is increased by a factor of 3 using a two-dimensional optical molasses which collimated the atomic beam before entering a Zeeman slower. A diode laser operating at 410.6 nm was employed to form optical molasses: The laser was heated to 70 Degree-Sign C by a two-step temperature stabilisation system. The laser system consisting of a master oscillator and an injection-locked amplifier emitted more than 100 mW at 410 nm and had a spectral linewidth of 0.6 MHz. (extreme light fields and their applications)

  2. Development of novel high-speed en face optical coherence tomography system using KTN optical beam deflector

    NASA Astrophysics Data System (ADS)

    Ohmi, Masato; Fukuda, Akihiro; Miyazu, Jun; Ueno, Masahiro; Toyoda, Seiji; Kobayashi, Junya

    2015-02-01

    We developed a novel high-speed en face optical coherence tomography (OCT) system using a KTa1-xNbxO3 (KTN) optical beam deflector. Using the imaging system, fast scanning was performed at 200 kHz by the KTN beam deflector, while slow scanning was performed at 400 Hz by the galvanometer mirror. In a preliminary experiment, we obtained en face OCT images of a human fingerprint at 400 fps. This is the highest speed reported in time-domain en face OCT imaging and is comparable to the speed of swept-source OCT. A 3D-OCT image of a sweat gland was also obtained by our imaging system.

  3. Study of beam optics and beam halo by integrated modeling of negative ion beams from plasma meniscus formation to beam acceleration

    SciTech Connect

    Miyamoto, K.; Okuda, S.; Hatayama, A.; Hanada, M.; Kojima, A.

    2013-01-14

    To understand the physical mechanism of the beam halo formation in negative ion beams, a two-dimensional particle-in-cell code for simulating the trajectories of negative ions created via surface production has been developed. The simulation code reproduces a beam halo observed in an actual negative ion beam. The negative ions extracted from the periphery of the plasma meniscus (an electro-static lens in a source plasma) are over-focused in the extractor due to large curvature of the meniscus.

  4. The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry

    PubMed Central

    Carbone, Ludovico; Fulda, Paul; Bond, Charlotte; Brueckner, Frank; Brown, Daniel; Wang, Mengyao; Lodhia, Deepali; Palmer, Rebecca; Freise, Andreas

    2013-01-01

    Thermal noise in high-reflectivity mirrors is a major impediment for several types of high-precision interferometric experiments that aim to reach the standard quantum limit or to cool mechanical systems to their quantum ground state. This is for example the case of future gravitational wave observatories, whose sensitivity to gravitational wave signals is expected to be limited in the most sensitive frequency band, by atomic vibration of their mirror masses. One promising approach being pursued to overcome this limitation is to employ higher-order Laguerre-Gauss (LG) optical beams in place of the conventionally used fundamental mode. Owing to their more homogeneous light intensity distribution these beams average more effectively over the thermally driven fluctuations of the mirror surface, which in turn reduces the uncertainty in the mirror position sensed by the laser light. We demonstrate a promising method to generate higher-order LG beams by shaping a fundamental Gaussian beam with the help of diffractive optical elements. We show that with conventional sensing and control techniques that are known for stabilizing fundamental laser beams, higher-order LG modes can be purified and stabilized just as well at a comparably high level. A set of diagnostic tools allows us to control and tailor the properties of generated LG beams. This enabled us to produce an LG beam with the highest purity reported to date. The demonstrated compatibility of higher-order LG modes with standard interferometry techniques and with the use of standard spherical optics makes them an ideal candidate for application in a future generation of high-precision interferometry. PMID:23962813

  5. Optical trapping with superfocused high-M2 laser diode beam

    NASA Astrophysics Data System (ADS)

    Sokolovskii, G. S.; Dudelev, V. V.; Melissinaki, V.; Losev, S. N.; Soboleva, K. K.; Deryagin, A. G.; Kuchinskii, V. I.; Farsari, M.; Sibbett, W.; Rafailov, E. U.

    2015-03-01

    Many applications of high-power laser diodes demand tight focusing. This is often not possible due to the multimode nature of semiconductor laser radiation possessing beam propagation parameter M2 values in double-digits. We propose a method of `interference' superfocusing of high-M2 diode laser beams with a technique developed for the generation of Bessel beams based on the employment of an axicon fabricated on the tip of a 100 μm diameter optical fiber with high-precision direct laser writing. Using axicons with apex angle 1400 and rounded tip area as small as ~10 μm diameter, we demonstrate 2-4 μm diameter focused laser `needle' beams with approximately 20 μm propagation length generated from multimode diode laser with beam propagation parameter M2=18 and emission wavelength of 960 nm. This is a few-fold reduction compared to the minimal focal spot size of ~11 μm that could be achieved if focused by an `ideal' lens of unity numerical aperture. The same technique using a 1600 axicon allowed us to demonstrate few-μm-wide laser `needle' beams with nearly 100 μm propagation length with which to demonstrate optical trapping of 5-6 μm rat blood red cells in a water-heparin solution. Our results indicate the good potential of superfocused diode laser beams for applications relating to optical trapping and manipulation of microscopic objects including living biological objects with aspirations towards subsequent novel lab-on-chip configurations.

  6. Phase signal of optical beam deflection from single microparticles: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Harada, Masaaki; Kitamori, Takehiko; Sawada, Tsuguo

    1993-03-01

    The optical beam deflection (OBD) signal from a single microparticulate sample was theoretically derived for the photothermal response to an intensity-modulated excitation in the transverse experimental configuration. The dependencies of phase signal on the normal and transverse offsets of the probe beam were calculated and then experimentally verified. The OBD phase signal was chosen as a means of inspecting the particle interior, since it contains information about the heat source depth. The results showed that the phase signal was independent of the excitation beam power and that the surface absorbing layer thickness could be estimated from the phase variation using the modulation frequency. The possibility of correcting beam offsets by the phase signal was also considered.

  7. ESA's Toolboxes for Optical Earth Observation Data: BEAM, CHRIS-Box and the Glob-Toolbox

    NASA Astrophysics Data System (ADS)

    Fomferra, Norman; Peters, Marco; Quast, Ralf; Zuhlke, Marco; Danne, Olaf; Storm, Thomas; Brockmann, Carsten; Regner, Peter

    2010-12-01

    With the launch of ENVISAT in 2002 ESA started the development of the Basic AATSR and MERIS toolbox BEAM [1]. With the requirement to be an open platform for scientists and operational users as well as software developers, ESA laid the foundation for this sustainable and successful open source software development project. Today BEAM is a toolbox and development platform supporting a wide range of optical sensors for Earth Observation, including SMOS, CHRIS/Proba, Landsat/TM, AVNIR, PRISM, MODIS and AVHRR, and enables importing of generic formats such as Geo-TIFF and NetCDF. Widely known is the interactive Visualisation and Analysis Tool VISAT of the BEAM toolbox. On top of the various EO data sources, a wide range of tools and data processors have meanwhile been developed for BEAM.

  8. Variable velocity range imaging of the choroid with dual-beam optical coherence angiography.

    PubMed

    Jaillon, Franck; Makita, Shuichi; Yasuno, Yoshiaki

    2012-01-02

    In this study, we present dual-beam Doppler optical coherence angiography with variable beam separation. Altering beam distance, independently of the scanning protocol, provides a flexible way to select the velocity range of detectable blood flow. This system utilized a one-micrometer wavelength light source to visualize deep into the posterior eye, i.e., the choroid. Two-dimensional choroidal vasculature maps of a human subject acquired with different beam separations, and hence with several velocity ranges, are presented. Combining these maps yields a semi-quantitative visualization of axial velocity of the choroidal circulation. The proposed technique may be useful for identifying choroidal abnormalities that occur in pathological conditions of the eye.

  9. Compact generation of superposed higher-order Bessel beams via composite diffractive optical elements

    NASA Astrophysics Data System (ADS)

    Vijayakumar, Anand; Bhattacharya, Shanti

    2015-11-01

    Binary composite diffractive optical elements with the functions of a spiral phase plate (SPP), an axicon, and a Fresnel zone lens (FZL) were designed with different topological charges. The element was designed in two steps. In the first step, the function of an SPP was combined with that of an axicon by spiraling the periods of the axicon with respect to the phase of the SPP followed by a modulo-2π phase addition with the phase of an FZL in the second step. The higher-order Bessel beams generated by the binary phase spiral axicon are superposed at the FZL's focal plane. Although location of the focal plane is wavelength dependent, the radius of the flower-like beams generated by the element was found to be independent of wavelength. The element was fabricated using electron-beam direct writing. The evaluation results matched well with the simulation results, generating flower-like beams at the focal plane of the FZL.

  10. Red blood cell micromanipulation with elliptical laser beam profile optical tweezers in different osmolarity conditions

    NASA Astrophysics Data System (ADS)

    Spyratou, E.; Makropoulou, M.; Serafetinides, A. A.

    2011-07-01

    In this work optical tweezers with elliptical beam profiles have been developed in order to examine the effect of optical force on fresh red blood cells (RBC) in isotonic, hypertonic and hypotonic buffer solutions. Considering that the optical force depends essentially on the cell surface and the cytoplasmic refractive index, it is obvious that biochemical modifications associated with different states of the cell will influence its behaviour in the optical trap. Line optical tweezers were used to manipulate simultaneously more than one red blood cell. After we have been manipulated a RBC with an elliptical laser beam profile in an isotonic or hypertonic buffer, we noticed that it rotates by itself when gets trapped by optical tweezers and undergoes folding. Further shape deformations can be observed attributed to the competition between alignment and rotational torque which are transferred by laser light to the cell. In hypotonic buffer RBCs become spherical and do not rotate or fold since the resultant force due to rays emerging from diametrically opposite points of the cell leads to zero torque. Manipulation of fresh red blood cells in isotonic solution by line optical tweezers leads to folding and elongation of trapped RBCs. Membrane elasticity properties such as bending modulus can be estimated by measuring RBC's folding time in function with laser power.

  11. The optical band gap and surface free energy of polyethylene modified by electron beam irradiations

    NASA Astrophysics Data System (ADS)

    Abdul-Kader, A. M.

    2013-04-01

    In this study, investigations have been carried out on electron beam irradiated ultra high molecular weight polyethylene (UHMWPE). Polyethylene samples were irradiated with 1.5 MeV electron beam at doses ranging from 50 to 500 kGy. Modifications in optical properties and photoluminescence behavior of the polymer were evaluated by UV-vis and photoluminescence techniques. Changes of surface layer composition of UHMWPE produced by electron irradiations were studied by Rutherford back scattering spectrometry (RBS). The change in wettability and surface free energy induced by irradiations was also investigated. The optical absorption studies reveal that both optical band gap and Urbach's energy decreases with increasing electron dose. A correlation between energy gap and the number of carbon atoms in clusters is discussed. Photoluminescence spectra were reveal remarkable decrease in the integrated luminescence intensity with increasing irradiation dose. Contact angle measurements showed that wettability and surface free energy increases with increasing the irradiation dose.

  12. Influence of the least-squares phase on optical vortices in strongly scintillated beams

    SciTech Connect

    Chen Mingzhou; Roux, Filippus S.

    2009-07-15

    The optical vortices that exist in strongly scintillated beams make it difficult for conventional adaptive optics systems to remove the phase distortions. When the least-squares reconstructed phase is removed, the vortices still remain. However, we found that the removal of the least-squares phase induces a portion of the vortices to be annihilated during subsequent propagation, causing a reduction in the total number of vortices. This can be understood in terms of the restoration of equilibrium between explicit vortices, which are visible in the phase function, and vortex bound states, which are somehow encoded in the continuous phase fluctuations. Numerical simulations are provided to show that the total number of optical vortices in a strongly scintillated beam can be reduced significantly after a few steps of least-squares phase corrections.

  13. Beam coupling in hybrid photorefractive inorganic-cholesteric liquid crystal cells: Impact of optical rotation

    SciTech Connect

    Reshetnyak, V. Yu.; Pinkevych, I. P.; Sluckin, T. J.; Cook, G.; Evans, D. R.

    2014-03-14

    We develop a theoretical model to describe two-beam energy exchange in a hybrid photorefractive inorganic-cholesteric cell. A cholesteric layer is placed between two inorganic substrates. One of the substrates is photorefractive (Ce:SBN). Weak and strong light beams are incident on the hybrid cell. The interfering light beams induce a periodic space-charge field in the photorefractive window. This penetrates into the cholesteric liquid crystal (LC), inducing a diffraction grating written on the LC director. In the theory, the flexoelectric mechanism for electric field-director coupling is more important than the LC static dielectric anisotropy coupling. The LC optics is described in the Bragg regime. Each beam induces two circular polarized waves propagating in the cholesteric cell with different velocities. The model thus includes optical rotation in the cholesteric LC. The incident light beam wavelength can fall above, below, or inside the cholesteric gap. The theory calculates the energy gain of the weak beam, as a result of its interaction with the pump beam within the diffraction grating. Theoretical results for exponential gain coefficients are compared with experimental results for hybrid cells filled with cholesteric mixture BL038/CB15 at different concentrations of chiral agent CB15. Reconciliation between theory and experiment requires the inclusion of a phenomenological multiplier in the magnitude of the director grating. This multiplier is cubic in the space-charge field, and we provide a justification of the q-dependence of the multiplier. Within this paradigm, we are able to fit theory to experimental data for cholesteric mixtures with different spectral position of cholesteric gap relative to the wavelength of incident beams, subject to the use of some fitting parameters.

  14. Multiple Fan-Beam Optical Tomography: Modelling Techniques

    PubMed Central

    Rahim, Ruzairi Abdul; Chen, Leong Lai; San, Chan Kok; Rahiman, Mohd Hafiz Fazalul; Fea, Pang Jon

    2009-01-01

    This paper explains in detail the solution to the forward and inverse problem faced in this research. In the forward problem section, the projection geometry and the sensor modelling are discussed. The dimensions, distributions and arrangements of the optical fibre sensors are determined based on the real hardware constructed and these are explained in the projection geometry section. The general idea in sensor modelling is to simulate an artificial environment, but with similar system properties, to predict the actual sensor values for various flow models in the hardware system. The sensitivity maps produced from the solution of the forward problems are important in reconstructing the tomographic image. PMID:22291523

  15. Optical Riblet Sensor: Beam Parameter Requirements for the Probing Laser Source.

    PubMed

    Tschentscher, Juliane; Hochheim, Sven; Brüning, Hauke; Brune, Kai; Voit, Kay-Michael; Imlau, Mirco

    2016-03-30

    Beam parameters of a probing laser source in an optical riblet sensor are studied by considering the high demands on a sensors' precision and reliability for the determination of deviations of the geometrical shape of a riblet. Mandatory requirements, such as minimum intensity and light polarization, are obtained by means of detailed inspection of the optical response of the riblet using ray and wave optics; the impact of wavelength is studied. Novel measures for analyzing the riblet shape without the necessity of a measurement with a reference sample are derived; reference values for an ideal riblet structure obtained with the optical riblet sensor are given. The application of a low-cost, frequency-doubled Nd:YVO₄ laser pointer sufficient to serve as a reliable laser source in an appropriate optical riblet sensor is discussed.

  16. Optical Riblet Sensor: Beam Parameter Requirements for the Probing Laser Source

    PubMed Central

    Tschentscher, Juliane; Hochheim, Sven; Brüning, Hauke; Brune, Kai; Voit, Kay-Michael; Imlau, Mirco

    2016-01-01

    Beam parameters of a probing laser source in an optical riblet sensor are studied by considering the high demands on a sensors’ precision and reliability for the determination of deviations of the geometrical shape of a riblet. Mandatory requirements, such as minimum intensity and light polarization, are obtained by means of detailed inspection of the optical response of the riblet using ray and wave optics; the impact of wavelength is studied. Novel measures for analyzing the riblet shape without the necessity of a measurement with a reference sample are derived; reference values for an ideal riblet structure obtained with the optical riblet sensor are given. The application of a low-cost, frequency-doubled Nd:YVO4 laser pointer sufficient to serve as a reliable laser source in an appropriate optical riblet sensor is discussed. PMID:27043567

  17. Beam optics and the pp2pp experiment at RHIC

    SciTech Connect

    Pile P. H.; Guryn, W.; Lee, J.H.; Tepikian, S.; Yip, K.

    2012-05-20

    The newly installed forward detector system at the STAR experiment at RHIC measures small angle elastic and inelastic scattering of polarized protons on polarized protons. The detector system makes use of a pair of Roman Pot (RP) detectors, instrumented with silicon detectors, and located on either side of the STAR intersection region downstream of the DX and D0 dipoles and quadrupole triplets. The parallel to point optics is designed so that scattering angles are determined from position measurements at the RP's with small error. The RP setup allows measurement of position and angle for a subset of the scattered protons. With this position/angle correlations at the RP's can be compared with optics model predictions to get a measure of the accuracy of the quadrupole triplet current settings. The current in each quadrupole in the triplets is comprised of sums and differences of up to six power supplies and an overall 1% error in the triplet field strengths results in a 4% error in four-momentum transfer squared. This technique is also useful to check the polarity of the skew elements located in each quadrupole triplet. Results of the analysis will be presented.

  18. Ion beam induced optical and surface modification in plasmonic nanostructures

    NASA Astrophysics Data System (ADS)

    Singh, Udai B.; Gautam, Subodh K.; Kumar, Sunil; Hooda, Sonu; Ojha, Sunil; Singh, Fouran

    2016-07-01

    In present work, ion irradiation induced nanostructuring has been exploited as an efficient and effective tool for synthesis of coupled plasmonics nanostructures by using 1.2 MeV Xe ions on Au/ZnO/Au system deposited on glass substrate. The results are correlated on the basis of their optical absorption, surface morphologies and enhanced sensitivity of evolved phonon modes by using UV Visible spectroscopy, scanning electron microscopy (SEM), and Raman spectroscopy (RS), respectively. Optical absorbance spectra of plasmonic nanostructures (NSs) show a decrease in band gap, which may be ascribed to the formation of defects with ion irradiation. The surface morphology reveals the formation of percolated NSs upon ion irradiation and Rutherford backscattering spectrometry (RBS) study clearly shows the formation of multilayer system. Furthermore, RS measurements on samples are studied to understand the enhanced sensitivity of ion irradiation induced phonon mode at 573 cm-1 along with other modes. As compared to pristine sample, a stronger and pronounced evolution of these phonon modes is observed with further ion irradiation, which indicates localized surface plasmon results with enhanced intensity of phonon modes of Zinc oxide (ZnO) material. Thus, such plasmonic NSs can be used as surface enhanced Raman scattering (SERS) substrates.

  19. Energy-efficient low-Fresnel-number Bessel beams and their application in optical coherence tomography.

    PubMed

    Lorenser, Dirk; Christian Singe, C; Curatolo, Andrea; Sampson, David D

    2014-02-01

    Bessel beams feature a very large depth-of-focus (DOF) compared to conventional focusing schemes, but their central lobe carries only a small fraction of the total beam power, leading to a strongly reduced peak irradiance. This is problematic for power-limited applications, such as optical coherence tomography (OCT) or optical coherence microscopy, as it can result in a prohibitive reduction of the signal-to-noise ratio (SNR). Using scalar diffraction theory, we show that the trade-off between DOF and peak irradiance of Bessel beams depends solely on the Fresnel number N. We demonstrate the existence of a low-Fresnel-number regime, N<10, in which axicons with Gaussian illumination can generate energy-efficient Bessel beams with a small number of sidelobes. In the context of OCT, this translates into DOF enhancements of up to 13× for a SNR penalty below 20 dB, which is confirmed by our experiments. We expect that these findings will enable improved performance of optical systems with extended DOF.

  20. Design and optimization of a highly efficient optical multipass system for γ-ray beam production from electron laser beam Compton scattering

    NASA Astrophysics Data System (ADS)

    Dupraz, K.; Cassou, K.; Delerue, N.; Fichot, P.; Martens, A.; Stocchi, A.; Variola, A.; Zomer, F.; Courjaud, A.; Mottay, E.; Druon, F.; Gatti, G.; Ghigo, A.; Hovsepian, T.; Riou, J. Y.; Wang, F.; Mueller, A. C.; Palumbo, L.; Serafini, L.; Tomassini, P.

    2014-03-01

    A new kind of nonresonant optical recirculator, dedicated to the production of γ rays by means of Compton backscattering, is described. This novel instrument, inspired by optical multipass systems, has its design focused on high flux and very small spectral bandwidth of the γ-ray beam. It has been developed to fulfill the project specifications of the European Extreme Light Infrastructure "Nuclear Pillar," i.e., the Gamma Beam System. Our system allows a single high power laser pulse to recirculate 32 times synchronized on the radio frequency driving accelerating cavities for the electron beam. Namely, the polarization of the laser beam and crossing angle between laser and electrons are preserved all along the 32 passes. Moreover, optical aberrations are kept at a negligible level. The general tools developed for designing, optimizing, and aligning the system are described. A detailed simulation demonstrates the high efficiency of the device.

  1. Non-intercepting diagnostic for high brightness electron beams using Optical Diffraction Radiation Interference (ODRI)

    NASA Astrophysics Data System (ADS)

    Cianchi, A.; Balandin, V.; Castellano, M.; Catani, L.; Chiadroni, E.; Gatti, G.; Golubeva, N.; Honkavaara, K.; Kube, G.

    2012-05-01

    High-gain Free Electron Lasers and future Linear Colliders require development of modern electron linacs with high brightness beams. Conventional intercepting transverse electron beam diagnostics, e.g. based on Optical Transition Radiation (OTR), cannot tolerate such high power beams without remarkable mechanical damages on the diagnostics device. Optical Diffraction Radiation (ODR) is an excellent candidate for measurements of the transverse phase space parameters in a non-intercepting way. One of the main problems of this method is the low signal to noise ratio, mainly due to the unavoidable synchrotron radiation background. This problem can be overcome by using two slits on metallic foils, placed at a distance shorter than the radiation formation zone. In this case a nearly background-free ODR interference pattern is produced allowing the determination of the beam size and angular divergence. The accuracy on these parameters can be increased by exploiting both ODR polarization states, as well as different wavelengths. Here we report measurements of the ODR interference between two slits with different aperture sizes in a non-collinear geometry, carried out at FLASH (DESY, Germany). Our results demonstrate the unique potential of this technique to determine the beam parameters.

  2. Quasi-optical Gaussian beam tracing to evaluate Doppler backscattering conditions

    NASA Astrophysics Data System (ADS)

    Honoré, C.; Hennequin, P.; Truc, A.; Quéméneur, A.

    2006-09-01

    Microwave beam backscattering near the cut-off layer appears to be the most interesting diagnostic to observe density fluctuation time evolution for a given localization in the plasma and at a defined wave vector. It also provides perpendicular plasma velocity. Scattering only occurs when the Bragg selection rule is fulfilled, i.e. when the scattering wave vector is almost perpendicular to the magnetic field. In order to evaluate these scattering conditions, ray tracing is required. 3D geometry is necessary to evaluate the angle between the magnetic field and the wave vector at the reflection. The ripple effect on the iso-index layer curve cannot be neglected. Scattering localization and wave vector resolution can be approached if single ray tracing is replaced with quasi-optical beam tracing. Optical propagation is still considered in the WKB approximation but the beam is described as multiple connected rays. The beam radial expansion due to diffraction is well described. This approach allows one to compute beam parameters for all data acquisitions (50 triggers per shot) and all shots (40 shots per day) during the following night on a recent personal computer with MatLab©.

  3. Propagation of a partially coherent hollow vortex Gaussian beam through a paraxial ABCD optical system in turbulent atmosphere.

    PubMed

    Zhou, Guoquan; Cai, Yangjian; Chu, Xiuxiang

    2012-04-23

    The propagation of a partially coherent hollow vortex Gaussian beam through a paraxial ABCD optical system in turbulent atmosphere has been investigated. The analytical expressions for the average intensity and the degree of the polarization of a partially coherent hollow vortex Gaussian beam through a paraxial ABCD optical system are derived in turbulent atmosphere, respectively. The average intensity distribution and the degree of the polarization of a partially coherent hollow vortex Gaussian beam in turbulent atmosphere are numerically demonstrated. The influences of the beam parameters, the topological charge, the transverse coherent lengths, and the structure constant of the atmospheric turbulence on the propagation of a partially coherent hollow vortex Gaussian beam in turbulent atmosphere are also examined in detail. This research is beneficial to the practical applications in free-space optical communications and the remote sensing of the dark hollow beams.

  4. Resolution of Transverse Electron Beam Measurements using Optical Transition Radiation

    SciTech Connect

    Ischebeck, Rasmus; Decker, Franz-Josef; Hogan, Mark; Iverson, Richard H.; Krejcik, Patrick; Lincoln, Melissa; Siemann, Robert H.; Walz, Dieter; Clayton, Chris E.; Huang, Chengkun; Lu, Wei; Deng, Suzhi; Oz, Erdem; /Southern California U.

    2005-06-22

    In the plasma wakefield acceleration experiment E-167, optical transition radiation is used to measure the transverse profile of the electron bunches before and after the plasma acceleration. The distribution of the electric field from a single electron does not give a point-like distribution on the detector, but has a certain extension. Additionally, the resolution of the imaging system is affected by aberrations. The transverse profile of the bunch is thus convolved with a point spread function (PSF). Algorithms that deconvolve the image can help to improve the resolution. Imaged test patterns are used to determine the modulation transfer function of the lens. From this, the PSF can be reconstructed. The Lucy-Richardson algorithm is used to deconvolute this PSF from test images.

  5. Optical Multiplications With Single Element 2-D Acousto-Optic Laser Beam Deflector

    NASA Astrophysics Data System (ADS)

    Soos, Jolanta I.; Leepa, Douglas C.; Rosemeier, Ronald G.

    1989-05-01

    With the current need for developing very fast computers in comparison to conventional digital chip based systems, the future for optical based signal processing is very bright. Attention has turned to a different application of optics utilizing mathematical operations, in which case operations are numerical, sometimes discrete, and often algebraic in nature. Interest has been so vigorous that many view it as a small revolution in optics, whereby optical signal processing is beginning to encompass what is frequently described as optical computing. The term is fully intended to imply a close comparison with the operations performed by scientific digital canputers. This paper will describe the applications of single element 2-D acousto-optic deflectors for optical multiplication systems.

  6. Electron beam fracturing of ZnO nanostructures and modification in optical band gap

    NASA Astrophysics Data System (ADS)

    Siraj, K.; Kanwal, M.; Saleem, S.; Pedarnig, J. D.; Rafique, M. S.; Naseem, S.

    2016-12-01

    In our previous work Siraj et al (J Alloys Comp 563:280, 2013), the electron beam irradiation at high energies (6-15 MeV) at constant dose of 30 Gy produced Zinc oxide elongated nanostructures and modified the optical band gap energies accordingly. In present work, those nanostructures are fractured to smaller sizes by increasing the electron doses to 100 and 200 Gy. The very high temperature gradient induced stresses are responsible for further fracturing of ZnO nanostructures. The optical properties such as refractive index, extinction coefficient and optical band gap energy have also modified when higher cumulative electron doses are used. The optical band gap energies are found to decrease by increasing electron doses at all used electron energies, which is attributed to the production of different defects like vacancies, unpaired bonds, nanovoids, nanocavities, nanocracks and high strains. The electron beam irradiation of ZnO thin films at used parameters (doses and energies) is found to be plausible technique to produce nanostructures of different sizes and accordingly modify the optical band gap energies. The results can be beneficial for optical and optoelectronic industries.

  7. RadSensor: Xray Detection by Direct Modulation of an Optical Probe Beam

    SciTech Connect

    Lowry, M E; Bennett, C V; Vernon, S P; Bond, T; Welty, R; Behymer, E; Petersen, H; Krey, A; Stewart, R; Kobayashi, N P; Sperry, V; Stephan, P; Reinhardt, C; Simpson, S; Stratton, P; Bionta, R; McKernan, M; Ables, E; Ott, L; Bond, S; Ayers, J.; Landen, O L; Bell, P M

    2003-08-01

    We present a new x-ray detection technique based on optical measurement of the effects of x-ray absorption and electron hole pair creation in a direct band-gap semiconductor. The electron-hole pairs create a frequency dependent shift in optical refractive index and absorption. This is sensed by simultaneously directing an optical carrier beam through the same volume of semiconducting medium that has experienced an xray induced modulation in the electron-hole population. If the operating wavelength of the optical carrier beam is chosen to be close to the semiconductor band-edge, the optical carrier will be modulated significantly in phase and amplitude. This approach should be simultaneously capable of very high sensitivity and excellent temporal response, even in the difficult high-energy xray regime. At xray photon energies near 10 keV and higher, we believe that sub-picosecond temporal responses are possible with near single xray photon sensitivity. The approach also allows for the convenient and EMI robust transport of high-bandwidth information via fiber optics. Furthermore, the technology can be scaled to imaging applications. The basic physics of the detector, implementation considerations, and preliminary experimental data are presented and discussed.

  8. Influence of the pump-to-laser beam overlap on the performance of optically pumped cesium vapor laser.

    PubMed

    Cohen, Tom; Lebiush, Eyal; Auslender, Ilya; Barmashenko, Boris D; Rosenwaks, Salman

    2016-06-27

    Experimental and theoretical study of the influence of the pump-to-laser beam overlap, a crucial parameter for optimization of optically pumped alkali atom lasers, is reported for Ti:Sapphire pumped Cs laser. Maximum laser power > 370 mW with an optical-to-optical efficiency of 43% and slope efficiency ~55% was obtained. The dependence of the lasing power on the pump power was found for different pump beam radii at constant laser beam radius. Non monotonic dependence of the laser power (optimized over the temperature of the Cs cell) on the pump beam radius was observed with a maximum achieved at the ratio ~0.7 between the pump and laser beam radii. The optimal temperature decreased with increasing pump beam radius. A simple optical model of the laser, where Gaussian spatial shapes of the pump and laser intensities in any cross section of the beams were assumed, was compared to the experiments. Good agreement was obtained between the measured and calculated dependence of the laser power on the pump power at different pump beam radii and also of the laser power, threshold pump power and optimal temperature on the pump beam radius. The model does not use empirical parameters such as mode overlap efficiency and can be applied to different Ti:Sapphire and diode pumped alkali lasers with arbitrary spatial distributions of the pump and laser beam widths.

  9. Reducing aberration effect of Fourier transform lens by modifying Fourier spectrum of diffractive optical element in beam shaping optical system.

    PubMed

    Zhang, Fang; Zhu, Jing; Song, Qiang; Yue, Weirui; Liu, Jingdan; Wang, Jian; Situ, Guohai; Huang, Huijie

    2015-10-20

    In general, Fourier transform lenses are considered as ideal in the design algorithms of diffractive optical elements (DOEs). However, the inherent aberrations of a real Fourier transform lens disturb the far field pattern. The difference between the generated pattern and the expected design will impact the system performance. Therefore, a method for modifying the Fourier spectrum of DOEs without introducing other optical elements to reduce the aberration effect of the Fourier transform lens is proposed. By applying this method, beam shaping performance is improved markedly for the optical system with a real Fourier transform lens. The experiments carried out with a commercial Fourier transform lens give evidence for this method. The method is capable of reducing the system complexity as well as improving its performance.

  10. FDTD approach to optical forces of tightly focused vector beams on metal particles.

    PubMed

    Qin, Jian-Qi; Wang, Xi-Lin; Jia, Ding; Chen, Jing; Fan, Ya-Xian; Ding, Jianping; Wang, Hui-Tian

    2009-05-11

    We propose an improved FDTD method to calculate the optical forces of tightly focused beams on microscopic metal particles. Comparison study on different kinds of tightly focused beams indicates that trapping efficiency can be altered by adjusting the polarization of the incident field. The results also show the size-dependence of trapping forces exerted on metal particles. Transverse tapping forces produced by different illumination wavelengths are also evaluated. The numeric simulation demonstrates the possibility of trapping moderate-sized metal particles whose radii are comparable to wavelength.

  11. Experimental validation of a transformation optics based lens for beam steering

    SciTech Connect

    Yi, Jianjia; Burokur, Shah Nawaz Lustrac, André de

    2015-10-12

    A transformation optics based lens for beam control is experimentally realized and measured at microwave frequencies. Laplace's equation is adopted to construct the mapping between the virtual and physical spaces. The metamaterial-based lens prototype is designed using electric LC resonators. A planar microstrip antenna source is used as transverse electric polarized wave launcher for the lens. Both the far field radiation patterns and the near-field distributions have been measured to experimentally demonstrate the beam steering properties. Measurements agree quantitatively and qualitatively with numerical simulations, and a non-narrow frequency bandwidth operation is observed.

  12. Optically-tunable beam steering grating based n azobenzene doped cholesteric liquid crystal.

    PubMed

    Jau, Hung-Chang; Lin, Tsung-Hsien; Fung, Ri-Xin; Huang, San-Yi; Liu, J-H; Fuh, Andy Y-G

    2010-08-02

    This work proposes an optically controllable beam-steering device, fabricated using cholesteric liquid crystals (CLCs) that are doped with azobenzene. The trans-cis photoisomerization of azobenzene changes the pitch of the CLC fingerprint structure and shifts the diffraction angle. The diffraction angle increases when the cell is irradiated with UV light, and restored when it is irradiated with green light. Combining the photoisomerization effect with electrical effect, the CLC beam-steering device provides a steering angle of approximately 19 degrees. The tuning is continuous and could be completed within a few seconds.

  13. Experimental validation of a transformation optics based lens for beam steering

    NASA Astrophysics Data System (ADS)

    Yi, Jianjia; Burokur, Shah Nawaz; de Lustrac, André

    2015-10-01

    A transformation optics based lens for beam control is experimentally realized and measured at microwave frequencies. Laplace's equation is adopted to construct the mapping between the virtual and physical spaces. The metamaterial-based lens prototype is designed using electric LC resonators. A planar microstrip antenna source is used as transverse electric polarized wave launcher for the lens. Both the far field radiation patterns and the near-field distributions have been measured to experimentally demonstrate the beam steering properties. Measurements agree quantitatively and qualitatively with numerical simulations, and a non-narrow frequency bandwidth operation is observed.

  14. Optical design and performance of the X25 hybrid wiggler beam line at the NSLS

    SciTech Connect

    Berman, L.E.; Hastings, J.B.; Oversluizen, T.; Woodle, M.

    1991-01-01

    The X25 beam line at the National Synchrotron Light Source (NSLS) began full-power commissioning in 1990. It extracts radiation from a 27 pole hybrid wiggler, which produces up to 1.8 kW of total power with a peak horizontal density of 450 W/mrad and critical energy of 4.6 keV. The design and performance of the beam line optics are described, in particular the cooling of the first monochromator crystal. 28 refs., 5 figs.

  15. (abstract) Optical Scattering and Surface Microroughness of Ion Beam Deposited Au and Pt Thin Films

    NASA Technical Reports Server (NTRS)

    Al-Jumaily, Ghanim A.; Raouf, Nasrat A.; Edlou, Samad M.; Simons, John C.

    1994-01-01

    Thin films of gold and platinum have been deposited onto superpolished fused silica substrates using thermal evaporation, ion assisted deposition (IAD), and ion assisted sputtering. The influence of ion beam flux, thin film material, and deposition rate on the films microroughness have been investigated. Short range surface microroughness of the films has been examined using scanning tunneling microscopy (STM) and atomic force microscopy (AFM). Long range surface microroughness has been characterized using an angle resolved optical scatterometer. Results indicate that ion beam deposited coatings have improved microstructure over thermally evaporated films.

  16. Diffractive optical elements on non-flat substrates using electron beam lithography

    NASA Technical Reports Server (NTRS)

    Maker, Paul D. (Inventor); Muller, Richard E. (Inventor); Wilson, Daniel W. (Inventor)

    2002-01-01

    The present disclosure describes a technique for creating diffraction gratings on curved surfaces with electron beam lithography. The curved surface can act as an optical element to produce flat and aberration-free images in imaging spectrometers. In addition, the fabrication technique can modify the power structure of the grating orders so that there is more energy in the first order than for a typical grating. The inventors noticed that by using electron-beam lithography techniques, a variety of convex gratings that are well-suited to the requirements of imaging spectrometers can be manufactured.

  17. Efficient out-coupling and beaming of Tamm optical states via surface plasmon polariton excitation

    SciTech Connect

    Lopez-Garcia, M.; Ho, Y.-L. D.; Taverne, M. P. C.; Chen, L.-F.; Rarity, J. G.; Oulton, R.; Murshidy, M. M.; Edwards, A. P.; Adawi, A. M.; Serry, M. Y.

    2014-06-09

    We present evidence of optical Tamm states to surface plasmon polariton (SPP) coupling. We experimentally demonstrate that for a Bragg stack with a thin metal layer on the surface, hybrid Tamm-SPP modes may be excited when a grating on the air-metal interface is introduced. Out-coupling via the grating to free space propagation is shown to enhance the transmission as well as the directionality and polarization selection for the transmitted beam. We suggest that this system will be useful on those devices, where a metallic electrical contact as well as beaming and polarization control is needed.

  18. Polarization and intensity correlations in stochastic electromagnetic beams upon interaction with devices of polarization optics

    NASA Astrophysics Data System (ADS)

    Jacks, H. C.; Korotkova, O.

    2011-05-01

    Based on the recently formulated unified theory of coherence and polarization of light, we explore the behavior of the intensity-intensity correlations and the auxiliary quantity called the degree of cross-polarization in stochastic electromagnetic beams upon their passage through the devices of polarization optics. In particular, the effects of deterministic devices (such as polarizers, absorbers, compensators, and rotators) as well as of random devices (such as spatial light modulators) on passing beams are investigated. Our results may find applications in polarimetric communications, imaging and sensing.

  19. Efficient out-coupling and beaming of Tamm optical states via surface plasmon polariton excitation

    NASA Astrophysics Data System (ADS)

    Lopez-Garcia, M.; Ho, Y.-L. D.; Taverne, M. P. C.; Chen, L.-F.; Murshidy, M. M.; Edwards, A. P.; Serry, M. Y.; Adawi, A. M.; Rarity, J. G.; Oulton, R.

    2014-06-01

    We present evidence of optical Tamm states to surface plasmon polariton (SPP) coupling. We experimentally demonstrate that for a Bragg stack with a thin metal layer on the surface, hybrid Tamm-SPP modes may be excited when a grating on the air-metal interface is introduced. Out-coupling via the grating to free space propagation is shown to enhance the transmission as well as the directionality and polarization selection for the transmitted beam. We suggest that this system will be useful on those devices, where a metallic electrical contact as well as beaming and polarization control is needed.

  20. Diffractive-optics-based beam combination of a phase-locked fiber laser array.

    PubMed

    Cheung, Eric C; Ho, James G; Goodno, Gregory D; Rice, Robert R; Rothenberg, Josh; Thielen, Peter; Weber, Mark; Wickham, Michael

    2008-02-15

    A diffractive optical element (DOE) is used as a beam combiner for an actively phase-locked array of fiber lasers. Use of a DOE eliminates the far-field sidelobes and the accompanying loss of beam quality typically observed in tiled coherent laser arrays. Using this technique, we demonstrated coherent combination of five fiber lasers with 91% efficiency and M2=1.04. Combination efficiency and phase locking is robust even with large amplitude and phase fluctuations on the input laser array elements. Calculations and power handling measurements suggest that this approach can scale to both high channel counts and high powers.

  1. Application of optical broadband monitoring to quasi-rugate filters by ion-beam sputtering.

    PubMed

    Lappschies, Marc; Görtz, Björn; Ristau, Detlev

    2006-03-01

    Methods for the manufacture of rugate filters by the ion-beam-sputtering process are presented. The first approach gives an example of a digitized version of a continuous-layer notch filter. This method allows the comparison of the basic theory of interference coatings containing thin layers with practical results. For the other methods, a movable zone target is employed to fabricate graded and gradual rugate filters. The examples demonstrate the potential of broadband optical monitoring in conjunction with the ion-beam-sputtering process. First-characterization results indicate that these types of filter may exhibit higher laser-induced damage-threshold values than those of classical filters.

  2. Beam width and transmitter power adaptive to tracking system performance for free-space optical communication.

    PubMed

    Arnon, S; Rotman, S; Kopeika, N S

    1997-08-20

    The basic free-space optical communication system includes at least two satellites. To communicate between them, the transmitter satellite must track the beacon of the receiver satellite and point the information optical beam in its direction. Optical tracking and pointing systems for free space suffer during tracking from high-amplitude vibration because of background radiation from interstellar objects such as the Sun, Moon, Earth, and stars in the tracking field of view or the mechanical impact from satellite internal and external sources. The vibrations of beam pointing increase the bit error rate and jam communication between the two satellites. One way to overcome this problem is to increase the satellite receiver beacon power. However, this solution requires increased power consumption and weight, both of which are disadvantageous in satellite development. Considering these facts, we derive a mathematical model of a communication system that adapts optimally the transmitter beam width and the transmitted power to the tracking system performance. Based on this model, we investigate the performance of a communication system with discrete element optical phased array transmitter telescope gain. An example for a practical communication system between a Low Earth Orbit Satellite and a Geostationary Earth Orbit Satellite is presented. From the results of this research it can be seen that a four-element adaptive transmitter telescope is sufficient to compensate for vibration amplitude doubling. The benefits of the proposed model are less required transmitter power and improved communication system performance.

  3. Propagation of an optical vortex carried by a partially coherent Laguerre-Gaussian beam in turbulent ocean.

    PubMed

    Cheng, Mingjian; Guo, Lixin; Li, Jiangting; Huang, Qingqing; Cheng, Qi; Zhang, Dan

    2016-06-10

    The analytical formulas for the orbital angular momentum (OAM) mode probability density, signal OAM mode detection probability, and spiral spectrum of partially coherent Laguerre-Gaussian (LG) beams with optical vortices propagation in weak horizontal oceanic turbulent channels were developed, based on the Rytov approximation theory. The effect of oceanic turbulence and beam source parameters on the propagation behavior of the optical vortices carried by partially coherent LG beams was investigated in detail. Our results indicated that optical turbulence in an ocean environment produced a much stronger effect on the optical vortex than that in an atmosphere environment; the effective range of the signal OAM mode of LG beams with a smaller ratio of the mode crosstalk was limited to only several tens of meters in turbulent ocean. The existence of oceanic turbulence evidently induced OAM mode crosstalk and spiral spectrum spread. The effects of oceanic turbulence on the OAM mode detection probability increased with the increase of radial and azimuthal mode orders, oceanic turbulent equivalent temperature structure parameter, and temperature-salinity balance parameter. The spatial partial coherence of the beam source would enhance the effect of turbulent aberrations on the signal OAM mode detection probability, and fully coherent vortex beams provided better performance than partially coherent ones. Increasing wavelength of the vortex beams would help improve the performance of this quantum optical communication system. These results might be of interest for the potential application of optical vortices in practical underwater quantum optical communication among divers, submarines, and sensors in the ocean environment.

  4. Response of Nanodot Optically Stimulated Luminescence Dosimeters to Therapeutic Electron Beams

    PubMed Central

    Ponmalar, Y. Retna; Manickam, Ravikumar; Sathiyan, S.; Ganesh, K. M.; Arun, R.; Godson, Henry Finlay

    2017-01-01

    Response of Al2O3:C-based nanoDot optically stimulated luminescence (OSL) dosimeter was studied for the dosimetry of 6, 9, 12, 16, and 20 MeV therapeutic electron beams. With reference to ionization chamber, no change in the response was observed with the change in the energy of electron beams for the field size from 6 cm × 6 cm to 25 cm × 25 cm, dose rates from 100 MU/min to 600 MU/min, and the linearity in the response up to 300 cGy. The fading of the transient signal was higher for 20 MeV electron beam than that of 6 MeV electron beam by about 5% as compared to value at 20 min after irradiation. The depletion of OSL signal per readout in 200 successive readouts was also found to change with dose and energy of electron beam from 6 MeV (9% and 12% per readout at 2 and 10 Gy, respectively) to 20 MeV (9% and 16% at 2 and 10 Gy, respectively). The OSL sensitivity changed in the range from 2% to 6% with accumulated doses from 2 to 8 Gy and with electron energy from 6 to 20 MeV, but the sensitivity could be reset using an optical annealing treatment. Although negligible fading for postirradiation storage from 20 min to several months, acceptable precision and linearity in the desired range, and high reproducibility makes nanoDot dosimeters very attractive for the dosimetry of therapeutic electron beams, a note should be made for changes in sensitivity at doses beyond 2 Gy and electron beams energy dependence in reuse, short-term fading, and signal depletion on repeated readout.

  5. Controlling laser beam irradiation area using an optical duplicate system to improve satellite-ground laser communications

    NASA Astrophysics Data System (ADS)

    Nakayama, Tomoko; Takayama, Yoshihisa; Fujikawa, Chiemi; Kodate, Kashiko

    2016-08-01

    To improve the quality of ground to satellite laser communications, we propose an optical duplicate system of the optical ground station. Our proposed approach can be used to control the beam irradiation area for a satellite position without changing the total power of the output beam and the mechanical drive unit; this is performed by controlling the input pattern of a liquid crystal filter inserted in the input plane of the optical duplicate system. Most of the power of the diffracted laser beam emitted from the ground is focused on the optical axis. By distributing the power to side lobes, it is possible to extend the coverage area for a satellite position. This system allows the laser beam irradiation area to be controlled by a sufficient degree by adjusting the threshold of the satellite reception level. We verify the efficacy of the system using wave optics numerical calculations.

  6. Characterizing the divergence properties of the laser diode beams propagation through collimator and aperture ABCD optical system

    NASA Astrophysics Data System (ADS)

    Reza Hedayati Rad, M.; Kashani, F. D.; Eftekhari, M. M.; Reza Mahzoun, M.

    2010-11-01

    The propagation properties of Gaussian laser beams through a complete optical path including free space and the optics of transmitter and receiver containing a collimator, an aperture and a lens is studied. Based on the Collins integral and using the second order moment method, analytical formulas for intensity distribution and Power In Bucket (PIB) along the propagation path are derived. The effects of initial beam divergence, collimator-source separation distance and beam width deviation on laser beams properties are investigated. Obtained results are confirmed and illustrated with numerical examples and resulted graphs.

  7. Measurement of wavefront and Wigner distribution function for optics alignment and full beam characterization of FELs

    NASA Astrophysics Data System (ADS)

    Mey, Tobias; Schäfer, Bernd; Mann, Klaus; Keitel, Barbara; Kreis, Svea; Kuhlmann, Marion; Plönjes, Elke; Tiedtke, Kai

    2013-05-01

    Free-electron lasers deliver EUV and soft x-ray pulses with the highest brilliance available and high spatial coherence. Users of such facilities have high demands on the coherence properties of the beam, for instance when working with coherent di ractive imaging (CDI). Experimentally, we are recovering the phase distribition with an EUV Hartmann wavefront sensor. This allows for online adjustment of focusing optics such as ellipsoidal or Kirkpatrick-Baez mirrors minimizing the aberrations in the focused beam. To gain highly resolved spatial coherence information, we have performed a caustic scan at beamline BL2 of the free-electron laser FLASH using the ellipsoidal focusing mirror and a movable EUV sensitized CCD detector. This measurement allows for retrieving the Wigner distribution function, being the two-dimensional Fourier transform of the mutual intensity of the beam. Computing the reconstruction on a four-dimensional grid, this yields the entire Wigner distribution which describes the beam propagation completely. Hence, we are able to provide comprehensive information about spatial coherence properties of the FLASH beam including the global degree of coherence. Additionally, we derive the beam propagation parameters such as Rayleigh length, waist diameter and M2.

  8. Dynamic analysis of trapping and escaping in dual beam optical trap

    NASA Astrophysics Data System (ADS)

    Li, Wenqiang; Hu, Huizhu; Su, Heming; Li, Zhenggang; Shen, Yu

    2016-10-01

    In this paper, we simulate the dynamic movement of a dielectric sphere in optical trap. This dynamic analysis can be used to calibrate optical forces, increase trapping efficiency and measure viscous coefficient of surrounding medium. Since an accurate dynamic analysis is based on a detailed force calculation, we calculate all forces a sphere receives. We get the forces of dual-beam gradient radiation pressure on a micron-sized dielectric sphere in the ray optics regime and utilize Einstein-Ornstein-Uhlenbeck to deal with its Brownian motion forces. Hydrodynamic viscous force also exists when the sphere moves in liquid. Forces from buoyance and gravity are also taken into consideration. Then we simulate trajectory of a sphere when it is subject to all these forces in a dual optical trap. From our dynamic analysis, the sphere can be trapped at an equilibrium point in static water, although it permanently fluctuates around the equilibrium point due to thermal effects. We go a step further to analyze the effects of misalignment of two optical traps. Trapping and escaping phenomena of the sphere in flowing water are also simulated. In flowing water, the sphere is dragged away from the equilibrium point. This dragging distance increases with the decrease of optical power, which results in escaping of the sphere with optical power below a threshold. In both trapping and escaping process we calculate the forces and position of the sphere. Finally, we analyze a trapping region in dual optical tweezers.

  9. Multiple optical trapping based on high-order axially symmetric polarized beams

    NASA Astrophysics Data System (ADS)

    Zhou, Zhe-Hai; Zhu, Lian-Qing

    2015-02-01

    Multiple optical trapping with high-order axially symmetric polarized beams (ASPBs) is studied theoretically, and a scheme based on far-field optical trapping with ASPBs is first proposed. The focused fields and the corresponding gradient forces on Rayleigh dielectric particles are calculated for the scheme. The calculated results indicate that multiple ultra-small focused spots can be achieved, and multiple nanometer-sized particles with refractive index higher than the ambient can be trapped simultaneously near these focused spots, which are expected to enhance the capabilities of traditional optical trapping systems and provide a solution for massive multiple optical trapping of nanometer-sized particles. Project supported by the National Natural Science Foundation of China (Grant Nos. 61108047 and 61475021), the Program for New Century Excellent Talents in University, China (Grant No. NCET-13-0667), and the Beijing Top Young Talents Support Program, China (Grant No. CIT&TCD201404113).

  10. Three-dimensional analysis of optical forces generated by an active tractor beam using radial polarization.

    PubMed

    Carretero, Luis; Acebal, Pablo; Blaya, Salvador

    2014-02-10

    We theoretically study the three-dimensional behavior of nanoparticles in an active optical conveyor. To do this, we solved the Langevin equation when the forces are generated by a focusing system at the near field. Analytical expressions for the optical forces generated by the optical conveyor were obtained by solving the Richards and Wolf vectorial diffraction integrals in an approximated form when a mask of two annular pupils is illuminated by a radially polarized Hermite-Gauss beam. Trajectories, in both the transverse plane and the longitudinal direction, are analyzed showing that the behavior of the optical conveyor can be optimized by conveniently choosing the configuration of the mask of the two annular pupils (inner and outer radius of the two rings) in order to trap and transport all particles at the focal plane.

  11. Molecular Beam Optical Study of Gold Sulfide and Gold Oxide

    NASA Astrophysics Data System (ADS)

    Zhang, Ruohan; Yu, Yuanqin; Steimle, Timothy

    2016-06-01

    Gold-sulfur and gold-oxygen bonds are key components to numerous established and emerging technologies that have applications as far ranging as medical imaging, catalysis, electronics, and material science. A major theoretical challenge for describing this bonding is correctly accounting for the large relativistic and electron correlation effects. Such effects are best studied in diatomic, AuX, molecules. Recently, the observed AuS electronic state energy ordering was measured and compared to a simple molecular orbital diagram prediction. Here we more thoroughly investigate the nature of the electronic states of both AuS and AuO from the analysis of high-resolution (FWHM\\cong35MHz) optical Zeeman spectroscopy of the (0,0){B}2Σ--{X}2Π3/2 bands. The determined fine and hyperfine parameters for the {B}2Σ- state of AuO differ from those extracted from the analysis of a hot, Doppler-limited, spectrum. It is demonstrated that the nature of the {B}2Σ- states of AuO and AuS are radically different. The magnetic tuning of AuO and AuS indicates that the {B}2Σ- states are heavily contaminated. Supported by the National Science Foundation under Grant No.1265885. D. L. Kokkin, R. Zhang, T. C. Steimle, I. A. Wyse, B. W. Pearlman and T. D. Varberg, J. Phys. Chem. A., 119(48), 4412, 2015. L. C. O'Brien, B. A. Borchert, A. Farquhar, S. Shaji, J. J. O'Brien and R. W. Field, J. Mol. Spectrosc., 252(2), 136, 2008

  12. LARGE ANGLE ELECTRO-OPTIC BEAM DEFLECTOR FOR THE INFRARED BASED ON A FERROELECTRIC.

    SciTech Connect

    Gahagan, K. T.; Casson, J. L.; Robinson, J. M.; Scymgeour, D. A.; Gopalan, V.; Libatique, N. J; Tafoya, J.; Jain, R.

    2001-01-01

    An electro-optic beam scanner fabricated on ferroelectric LiTaO{sub 3} is demonstrated which is capable of continuously scanning at wavelengths ranging from 0.4-5 {micro}m. The scanning performance varied from a total deflection angle of 13.38{sup o} at 1558 nm to 16.18{sup o} at 632.8 nm. The dispersion of the r{sub 33} and r{sub 13} electro-optic coefficients of LiTaO{sub 3} with wavelength was also determined.

  13. Structural and optical properties of electron beam evaporated yttria stabilized zirconia thin films

    SciTech Connect

    Kirubaharan, A. Kamalan; Kuppusami, P. Dharini, T.; Ramachandran, D.; Singh, Akash; Mohandas, E.

    2015-06-24

    Yttria stabilized zirconia (10 mole % Y{sub 2}O{sub 3}) thin films were deposited on quartz substrates using electron beam physical vapor deposition at the substrate temperatures in the range 300 – 973 K. XRD analysis showed cubic crystalline phase of YSZ films with preferred orientation along (111). The surface roughness was found to increase with the increase of deposition temperatures. The optical band gap of ∼5.7 eV was calculated from transmittance curves. The variation in the optical properties is correlated with the changes in the microstructural features of the films prepared as a function of substrate temperature.

  14. Total retinal blood flow measurement by three beam Doppler optical coherence tomography

    PubMed Central

    Haindl, Richard; Trasischker, Wolfgang; Wartak, Andreas; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K.

    2016-01-01

    We present measurements of total retinal blood flow in healthy volunteers using a three beam Doppler optical coherence tomography (D-OCT) technique. This technology has the advantage of a precise determination of the flow vector without the use of any a-priori information on the vessel geometry. Circular D-OCT scans around the optic disc were recorded and venous as well as arterial total blood flow was determined and compared for each subject. The reproducibility of the method was assessed in 6 subjects by repeated measurements. Only small deviations of around 6% between the measurements were found which indicates the high precision of the proposed method. PMID:26977340

  15. What is the Temporal Analog of Reflection and Refraction of Optical Beams?

    PubMed

    Plansinis, B W; Donaldson, W R; Agrawal, G P

    2015-10-30

    It is shown numerically and analytically that when an optical pulse approaches a moving temporal boundary across which the refractive index changes, it undergoes a temporal equivalent of reflection and refraction of optical beams at a spatial boundary. The main difference is that the role of angles is played by changes in the frequency. The frequency dependence of the dispersion of the material in which the pulse is propagating plays a fundamental role in determining the frequency shifts experienced by the reflected and refracted pulses. Our analytic expressions for these frequency shifts allow us to find the condition under which an analog of total internal reflection may occur at the temporal boundary.

  16. Advanced matrix-based algorithm for ion-beam milling of optical components

    NASA Astrophysics Data System (ADS)

    Carnal, Charles L.; Egert, Charles M.; Hylton, Kathy W.

    1992-12-01

    Control of an ion beam for milling optical surfaces is a nontrivial problem in two-dimensional deconvolution. The ion milling operation is performed by moving an ion beam gun through a grid of points over the surface of an optical workpiece. The control problem is to determine the amount of time to dwell at each point in the grid to obtain a desired surface profile. This research treats the problem in linear algebra terms. The required dwell times are the solutions to a large, sparse system of linear equations. Traditional factorization methods such as Gaussian elimination cannot be used because the linear equations are severely ill conditioned. Theoretically, a least-squares solution to this problem exists. Practical approaches to finding a minimal least-squares solution are discussed.

  17. On astigmatism of multi-beam optical stress sensor mounted at large incident angle

    NASA Astrophysics Data System (ADS)

    Jiang, Jinbo; Hwang, Heedon; Lee, Hak Sun; Kim, Byongju; Bong, Kee; Yoon, Euijoon

    2004-01-01

    When multi-beam optical stress sensor (MOSS) system is mounted at a large incident angle ( α), despite an improvement of the resolution in the measurements, it also induces optical astigmatism in the spot images on a charge-coupled device. During epitaxial growth, as the film stress increases, the astigmatism may result in the beam deflection changing at different rates in the directions parallel and perpendicular to the incident plane, if the α is large. In this paper, the system error due to the astigmatism is analyzed by the ray-tracing method and its predictions are compared with the experimental results. It is demonstrated here, how the spot spacing changes along the above mentioned orthogonal directions can be considered separately to minimize the error due to astigmatism in the MOSS measurements at any large α.

  18. Generalized Stokes parameters of a stochastic electromagnetic beam propagating through a paraxial ABCD optical system.

    PubMed

    Zhu, Yingbin; Zhao, Daomu

    2008-08-01

    On the basis of the generalized diffraction integral formula for an ABCD optical system in the spatial domain, a propagation law for the generalized Stokes parameters of a stochastic electromagnetic beam passing through an ABCD optical system is obtained. We describe the Stokes parameters of the source as linear combinations of the elements of the cross-spectral density matrix, and study the changes in the spectral degree of polarization and in the state of the polarization ellipse of a stochastic electromagnetic Gaussian Schell-model beam propagating through a gradient-index fiber with the help of generalized Stokes parameters and the cross-spectral density matrix. The medium has significant effect on the change of the spectral degree of polarization. However, when the correlation coefficients of the source satisfy the relation delta(xx)=delta(yy)=delta(xy)=delta(yx), the medium does not influence the spectral degree of polarization.

  19. Non-linear optical flow cytometry using a scanned, Bessel beam light-sheet.

    PubMed

    Collier, Bradley B; Awasthi, Samir; Lieu, Deborah K; Chan, James W

    2015-05-29

    Modern flow cytometry instruments have become vital tools for high-throughput analysis of single cells. However, as issues with the cellular labeling techniques often used in flow cytometry have become more of a concern, the development of label-free modalities for cellular analysis is increasingly desired. Non-linear optical phenomena (NLO) are of growing interest for label-free analysis because of the ability to measure the intrinsic optical response of biomolecules found in cells. We demonstrate that a light-sheet consisting of a scanned Bessel beam is an optimal excitation geometry for efficiently generating NLO signals in a microfluidic environment. The balance of photon density and cross-sectional area provided by the light-sheet allowed significantly larger two-photon fluorescence intensities to be measured in a model polystyrene microparticle system compared to measurements made using other excitation focal geometries, including a relaxed Gaussian excitation beam often used in conventional flow cytometers.

  20. An optical beam frequency reference with 10{sup -14} range frequency instability

    SciTech Connect

    McFerran, J. J.; Hartnett, J. G.; Luiten, A. N.

    2009-07-20

    The authors report on a thermal beam optical frequency reference with a fractional frequency instability of 9.2x10{sup -14} at 1 s reducing to 2.0x10{sup -14} at 64 s before slowly rising. The {sup 1}S{sub 0}{r_reversible}{sup 3}P{sub 1} intercombination line in neutral {sup 40}Ca is used as a frequency discriminator. A diode laser at 423 nm probes the ground state population after a Ramsey-Borde sequence of 657 nm light-field interactions on the atoms. The measured fractional frequency instability is an order of magnitude improvement on previously reported thermal beam optical clocks. The photon shot-noise of the read-out produces a limiting square root {lambda}-variance of 7x10{sup -14}/{radical}({tau})

  1. Studies on transmitted beam modulation effect from laser induced damage on fused silica optics.

    PubMed

    Zheng, Yi; Ma, Ping; Li, Haibo; Liu, Zhichao; Chen, Songlin

    2013-07-15

    UV laser induced damage (LID) on exit surface of fused silica could cause modulation effect to transmitted beam and further influence downstream propagation properties. This paper presents our experimental and analytical studies on this topic. In experiment, a series of measurement instruments are applied, including beam profiler, interferometer, microscope, and optical coherent tomography (OCT). Creating and characterizing of LID on fused silica sample have been implemented. Morphological features are studied based on their particular modulation effects on transmitted beam. In theoretical investigation, analytical modeling and numerical simulation are performed. Modulation effects from amplitude, phase, and size factors are analyzed respectively. Furthermore, we have novelly designed a simplified polygon model to simulate actual damage site with multiform modulation features, and the simulation results demonstrate that the modeling is usable and representative.

  2. Geometrical optics of beams with vortices: Berry phase and orbital angular momentum Hall effect.

    PubMed

    Bliokh, Konstantin Yu

    2006-07-28

    We consider propagation of a paraxial beam carrying the spin angular momentum (polarization) and intrinsic orbital angular momentum (IOAM) in a smoothly inhomogeneous isotropic medium. It is shown that the presence of IOAM can dramatically enhance and rearrange the topological phenomena that previously were considered solely in connection to the polarization of transverse waves. In particular, the appearance of a new type of Berry phase that describes the parallel transport of the beam structure along a curved ray is predicted. We derive the ray equations demonstrating the splitting of beams with different values of IOAM. This is the orbital angular momentum Hall effect, which resembles the Magnus effect for optical vortices. Unlike the spin Hall effect of photons, it can be much larger in magnitude and is inherent to waves of any nature. Experimental means to detect the phenomena are discussed.

  3. Hardware Implementation of Multiple Fan Beam Projection Technique in Optical Fibre Process Tomography

    PubMed Central

    Rahim, Ruzairi Abdul; Fazalul Rahiman, Mohd Hafiz; Leong, Lai Chen; Chan, Kok San; Pang, Jon Fea

    2008-01-01

    The main objective of this project is to implement the multiple fan beam projection technique using optical fibre sensors with the aim to achieve a high data acquisition rate. Multiple fan beam projection technique here is defined as allowing more than one emitter to transmit light at the same time using the switch-mode fan beam method. For the thirty-two pairs of sensors used, the 2-projection technique and 4-projection technique are being investigated. Sixteen sets of projections will complete one frame of light emission for the 2-projection technique while eight sets of projection will complete one frame of light emission for the 4-projection technique. In order to facilitate data acquisition process, PIC microcontroller and the sample and hold circuit are being used. This paper summarizes the hardware configuration and design for this project. PMID:27879885

  4. Emittance and Energy Measurements of Low-Energy Electron Beam Using Optical Transition Radiation Techniques

    NASA Astrophysics Data System (ADS)

    Sakamoto, Fumito; Iijima, Hokuto; Dobashi, Katsuhiro; Imai, Takayuki; Ueda, Toru; Watanabe, Takahiro; Uesaka, Mitsuru

    2005-03-01

    Emittance and energy of an electron beam in the range of 8 to 22 MeV were measured via optical transition radiation (OTR) techniques. The beam divergence effect on observations of the far-field OTR image at low energies was studied by means of numerical analysis. The numerical analysis indicates that if the beam divergence is under 1.5 mrad, a simultaneous single-shot measurement of emittance and energy is possible. The results of the single-shot experiment agree with independent measurements conducted using the quadrupole scan method and an electron spectrometer. The experiments were performed with an S-band linac at the Nuclear Engineering Research Laboratory, The University of Tokyo (UTNL).

  5. New electron optical column with large field for nanometer e-beam lithography system

    NASA Astrophysics Data System (ADS)

    Ohta, Hiroya; Matsuzaka, Takashi; Saitou, Norio

    1995-05-01

    An electron beam lithography system for nanometer devices has been developed. The target specifications of the system are a Gaussian beam diameter of 10 nm and a beam current of 1 nA, an acceleration voltage of 50 kV, a 500 micrometers X 500 micrometers deflection field and an overlay accuracy of 10 nm (3(sigma) ). To realize such high performance, the following two technologies have been developed for the design of the electron optical column: (1) a low aberration objective lens system with a one stage electrostatic deflector and (2) a thermal field emission (TFE) gun system with a low energy spread and a high brightness Zr/O/W cathode. The exposed results shown are a 30 nm isolated line and a 40 nm lines and spaces. An overlay accuracy of 10 nm are also obtained. This system is capable of being put into practical use in the fabrication of nanometer devices.

  6. Beam-splitting code for light scattering by ice crystal particles within geometric-optics approximation

    NASA Astrophysics Data System (ADS)

    Konoshonkin, Alexander V.; Kustova, Natalia V.; Borovoi, Anatoli G.

    2015-10-01

    The open-source beam-splitting code is described which implements the geometric-optics approximation to light scattering by convex faceted particles. This code is written in C++ as a library which can be easy applied to a particular light scattering problem. The code uses only standard components, that makes it to be a cross-platform solution and provides its compatibility to popular Integrated Development Environments (IDE's). The included example of solving the light scattering by a randomly oriented ice crystal is written using Qt 5.1, consequently it is a cross-platform solution, too. Both physical and computational aspects of the beam-splitting algorithm are discussed. Computational speed of the beam-splitting code is obviously higher compared to the conventional ray-tracing codes. A comparison of the phase matrix as computed by our code with the ray-tracing code by A. Macke shows excellent agreement.

  7. Geometrical Optics of Beams with Vortices: Berry Phase and Orbital Angular Momentum Hall Effect

    SciTech Connect

    Bliokh, Konstantin Yu.

    2006-07-28

    We consider propagation of a paraxial beam carrying the spin angular momentum (polarization) and intrinsic orbital angular momentum (IOAM) in a smoothly inhomogeneous isotropic medium. It is shown that the presence of IOAM can dramatically enhance and rearrange the topological phenomena that previously were considered solely in connection to the polarization of transverse waves. In particular, the appearance of a new type of Berry phase that describes the parallel transport of the beam structure along a curved ray is predicted. We derive the ray equations demonstrating the splitting of beams with different values of IOAM. This is the orbital angular momentum Hall effect, which resembles the Magnus effect for optical vortices. Unlike the spin Hall effect of photons, it can be much larger in magnitude and is inherent to waves of any nature. Experimental means to detect the phenomena are discussed.

  8. Laser-electron beam interaction applied to optical amplifiers and oscillators

    NASA Technical Reports Server (NTRS)

    Pantell, R. H.; Piestrup, M. A.

    1976-01-01

    Momentum modulation of a relativistic electron beam by a Nd:YAG laser is demonstrated. The electrons, at 100 MeV energy, interact with the laser light in helium gas at standard temperature and pressure. At an angle of 6.55 mrad between the two wavevectors, corresponding to the Cerenkov angle, a given electron remains in a field of constant phase as it passes through the light beam. The experimental arrangement is illustrated showing the trajectories of the electron and light. The particle momentum is measured by a mass spectrometer, and the angle between the wavevectors is controlled by a rotatable mirror. Experimental results indicate that momentum modulation of an electron beam may be used for amplification. A possible configuration for an optical klystron is illustrated.

  9. Total retinal blood flow and reproducibility evaluation by three beam optical Doppler tomography

    NASA Astrophysics Data System (ADS)

    Haindl, Richard; Trasischker, Wolfgang; Wartak, Andreas; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K.

    2016-03-01

    We present a three beam optical Doppler tomography (ODT) technique suitable for 3-D velocity and flow measurements to evaluate total retinal blood circulation from and to the optic nerve head (ONH). The system consists of three independent ODT channels. Superluminescent diodes with a central wavelength of 840 nm and a spectral bandwidth of 50 nm were used. The sources are coupled to collimators resting in a specially designed mount to ensure a well-defined beam geometry, necessary for the full reconstruction of the three dimensional velocity vector. The reconstruction works without prior knowledge on the vessel geometry, which is normally required for ODT systems with less than three beams. The beams share a common bulk optics Michelson interferometer, while the detection comprises three identical spectrometers with a line scan rate of 50 kHz. 20 eyes of healthy volunteers were imaged with the 3 beam ODT, employing a circular scan pattern around the ONH. The mean total blood flow was calculated for arteries (47.1 +/- 2.4 μl/min (mean +/- SD)) and veins (47.1 +/- 2.7 μl/min μl/min) independently. The two results showed no significant difference (paired t-test, p < 0.96), rendering both equally reliable for total flow measurements. Furthermore the reproducibility of the method was evaluated for the total flow and flow, velocities within each individual vessel of 6 eyes. The average variation for total flow measurements is sufficiently low to detect deviations of ~ 6% indicating high precision of the proposed method.

  10. Modification of the velocity distribution of H(2) molecules in a supersonic beam by intense pulsed optical gradients.

    PubMed

    Ramirez-Serrano, Jaime; Strecker, Kevin E; Chandler, David W

    2006-07-07

    We report the acceleration and deceleration of H(2) molecules in a supersonic molecular beam by means of its interaction with an intense optical gradient from a nanosecond far-off-resonant optical pulse. The strong optical gradients are formed in the interference pattern of two intense optical pulses at 532 nm. The velocity distribution of the molecular beam, before and after the applied optical pulse, is measured by a velocity-mapped ion imaging technique. Changes in velocity up to 202 m s(-1)+/- 61 m s(-1) are observed in a molecular beam initially travelling at a mean speed of 563 m s(-1). We report the dependence of this change in velocity with the strength of the optical gradient applied.

  11. Analysis of surface plasmon interference pattern formed by optical vortex beams.

    PubMed

    Tan, P S; Yuan, X-C; Lin, J; Wang, Q; Burge, R E

    2008-10-27

    Following our recent experimental approach to excitation of surface plasmon polaritons induced by optical vortex beams [5], we report further analysis and verification of the surface plasmon interference pattern formed by locally excited standing surface plasmon polaritons in a metal/dielectric film. Our simulation model can be demonstrated by using angular spectrum representation. The generated standing interference pattern has potential as a resolution enhancement technique for sub-diffraction imaging.

  12. Observation of Shot Noise Suppression at Optical Wavelengths in a Relativistic Electron Beam

    SciTech Connect

    Ratner, Daniel; Stupakov, Gennady; /SLAC

    2012-06-19

    Control of collective properties of relativistic particles is increasingly important in modern accelerators. In particular, shot noise affects accelerator performance by driving instabilities or by competing with coherent processes. We present experimental observations of shot noise suppression in a relativistic beam at the Linac Coherent Light Source. By adjusting the dispersive strength of a chicane, we observe a decrease in the optical transition radiation emitted from a downstream foil. We show agreement between the experimental results, theoretical models, and 3D particle simulations.

  13. Nd:YAG laser bloodless tonsillectomy by fiber optic doppler coupled handpiece beam delivery

    NASA Astrophysics Data System (ADS)

    Palmieri, Beniamino; Rottigni, Valentina

    2012-09-01

    Laser ablation of palatine tonsils is a relatively new technique recently performed in head and neck surgery departments, in order to treat recurrent tonsillar infections or obstructions from enlarged tonsils. In our study, we have investigated a new procedure using the fiber optic laser beam Nd:YAG to remove up to the 89% of tonsillar tissue, and leaving in place the capsule avoiding any hemorrhagic complication and limiting the pain.

  14. All-optical optoacoustic microscopy system based on probe beam deflection technique

    NASA Astrophysics Data System (ADS)

    Maswadi, Saher M.; Tsyboulskic, Dmitri; Roth, Caleb C.; Glickman, Randolph D.; Beier, Hope T.; Oraevsky, Alexander A.; Ibey, Bennett L.

    2016-03-01

    It is difficult to achieve sub-micron resolution in backward mode OA microscopy using conventional piezoelectric detectors, because of wavefront distortions caused by components placed in the optical path, between the sample and the objective lens, that are required to separate the acoustic wave from the optical beam. As an alternate approach, an optoacoustic microscope (OAM) was constructed using the probe beam deflection technique (PBDT) to detect laserinduced acoustic signals. The all-optical OAM detects laser-generated pressure waves using a probe beam passing through a coupling medium, such as water, filling the space between the microscope objective lens and sample. The acoustic waves generated in the sample propagate through the coupling medium, causing transient changes in the refractive index that deflect the probe beam. These deflections are measured with a high-speed, balanced photodiode position detector. The deflection amplitude is directly proportional to the magnitude of the acoustic pressure wave, and provides the data required for image reconstruction. The sensitivity of the PBDT detector expressed as noise equivalent pressure was 12 Pa, comparable to that of existing high-performance ultrasound detectors. Because of the unimpeded working distance, a high numerical aperture objective lens, i.e. NA = 1, was employed in the OAM to achieve near diffraction-limited lateral resolution of 0.5 μm at 532nm. The all-optical OAM provides several benefits over current piezoelectric detector-based systems, such as increased lateral and axial resolution, higher sensitivity, robustness, and potentially more compatibility with multimodal instruments.

  15. Gaps of free-space optics beams with the Beer-Lambert law.

    PubMed

    Lacaze, Bernard

    2009-05-10

    Lasers used in free-space optics propagate a beam within a truncated cone. Because of this shape, the intensity cannot follow the Beer-Lambert law. In the case of a homogeneous atmosphere, we calculate the gap from the cylinder case. We will see that the gap exists but is generally very weak and, therefore, that the use of the Beer-Lambert law is a justified approximation.

  16. Absolute Retinal Blood Flow Measurement With a Dual-Beam Doppler Optical Coherence Tomography

    PubMed Central

    Dai, Cuixia; Liu, Xiaojing; Zhang, Hao F.; Puliafito, Carmen A.; Jiao, Shuliang

    2013-01-01

    Purpose. To test the capability of a novel dual-beam Doppler optical coherence tomography (OCT) technique for simultaneous in vivo measurement of the Doppler angle and, thus, the absolute retinal blood velocity and the retinal flow rate, without the influence of motion artifacts. Methods. A novel dual-beam Doppler spectral domain OCT (SD-OCT) was developed. The two probing beams are separated with a controllable distance along an arbitrary direction, both of which are controlled by two independent 2D optical scanners. Two sets of optical Doppler tomography (ODT) images are acquired simultaneously. The Doppler angle of each blood vessel segment is calculated from the relative coordinates of the centers of the blood vessel in the two corresponding ODT images. The absolute blood flow velocity and the volumetric blood flow rate can then be calculated. To measure the total retinal blood flow, we used a circular scan pattern centered at the optic disc to obtain two sets of concentric OCT/ODT images simultaneously. Results. We imaged two normal human subjects at ages of 48 and 34 years. The total retinal blood flow rates of the two human subjects were calculated to be 47.01 μL/min (older subject) and 51.37 μL/min (younger subject), respectively. Results showed that the performance of this imaging system is immune to eye movement, since the two sets of ODT images were acquired simultaneously. Conclusions. The dual-beam OCT/ODT system is successful in measuring the absolute retinal blood velocity and the volumetric flow rate. The advantage of the technique is that the two sets of ODT images used for the calculation are acquired simultaneously, which eliminates the influence of eye motion and ensures the accuracy of the calculated hemodynamic parameters. PMID:24222303

  17. Three-dimensional ultrashort optical Airy beams in an inhomogeneous medium with carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Zhukov, Alexander V.; Bouffanais, Roland; Belonenko, Mikhail B.; Dvuzhilov, Ilya S.

    2017-03-01

    In this Letter, we consider the problem of the dynamics of propagation of three-dimensional optical pulses (a.k.a. light bullets) with an Airy profile through a heterogeneous environment of carbon nanotubes. We show numerically that such beams exhibit sustained and stable propagation. Moreover, we demonstrate that by varying the density modulation period of the carbon nanotubes one can indirectly control the pulse velocity, which is a particularly valuable feature for the design and manufacturing of novel pulse delay devices.

  18. Stress control in optical thin films by sputtering and electron beam evaporation.

    PubMed

    Tajima, Naoya; Murotani, Hiroshi; Matsumoto, Shigeharu; Honda, Hiromitsu

    2017-02-01

    It is necessary to control the internal stress of optical thin films in order to address problems such as peeling and cracking. Internal stress differs among films prepared by different deposition methods. We investigated the internal stress of films prepared by sputtering, electron beam (EB) evaporation, and a combination deposition method that we developed. The internal stress was successfully controlled, showing a value between that of EB evaporation and sputtering.

  19. Observation of dynamic wavelength shifts of a four-beam laser diode and study of its adaptability to optical heads.

    PubMed

    Shinoda, M; Kime, K

    1995-04-01

    Dynamic wavelength shifts for a four-beam laser diode were observed with a streak camera system. The wavelength shift does not exceed 2 nm for pulsed laser beam operation at a bottom power of 5 mW and a peak power of 40 mW. For a 5-mW continuous operation laser beam, the induced wavelength shift in the presence of another laser beam under the above pulse condition does not exceed 1 nm. The observed wavelength shifts are small enough for practical use, and this four-beam laser diode can be successfully applied to multibeam optical heads for parallel data processing.

  20. Optical Tagging of Ion Beams Accelerated by Double Layers in Laboratory Plasma

    NASA Astrophysics Data System (ADS)

    Good, Timothy; Aguirre, Evan; Thompson, Derek; Scime, Earl

    2016-10-01

    Experiments in helicon sources that investigate plasma expansion into weakly magnetized, low density regions reveal the production of supersonic ion beams attributed to acceleration by spatially localized double layer structures. Current efforts are aimed at mapping the ion velocity flow field utilizing 2D spatially scanning laser induced fluorescence (LIF) probes that yield metastable ion velocity distribution functions (IVDF) for velocities along and perpendicular to the flow. Observation of metastable ion beams by LIF renders plausible a Lagrangian approach to studying the field-ion interaction via optical tagging. We propose a tagging scheme in which metastable state ion populations are modulated by optical pumping upstream of the double layer and the synchronous detection of LIF at the ion beam velocity is recorded downstream. Besides the unambiguous identification of the source of beam ions, this method can provide detailed dynamical information through time of flight analysis. Preliminary results will be presented. Please include this poster in session that includes poster authored by Evan Aguirre et al.

  1. Potential of vortex beams with orbital angular momentum modulation for deep-space optical communication

    NASA Astrophysics Data System (ADS)

    Wang, Xiaorui; Liu, Yejun; Guo, Lei; Li, Hui

    2014-05-01

    In order to achieve multigigabit transmission in deep-space optical communication, our study applies a new modulation mode named orbital angular momentum (OAM) modulation, and uses the encoded OAM states of single photon as data information carriers, thus providing a reliable and high-speed transmission of signals. According to the long link characteristic of deep-space communication, we conduct a reasonable deployment for communication nodes in deep-space environment. First, we present the reliability of deep-space channel and analyze the data rate and spectral efficiency of beams with OAM. Second, we study the characteristics and generations of vortex beams with OAM by simulation. Results show that vortex beams have better spatial multiplexing capability of realizing high capacity data transmission. Finally, we propose an encoding method with OAM states of single photon. The transceiver units are based on spatial light modulators to perform the modulation and demodulation of vortex beams. At the receiver, the charged-coupled device camera is used to detect the signal intensity and decodes the OAM states. Our proposal not only ensures the confidentiality of deep-space optical communication, but also greatly increases the transmission rate.

  2. Femtosecond laser-induced damage threshold of electron beam deposited dielectrics for 1-m class optics

    NASA Astrophysics Data System (ADS)

    Hervy, Adrien; Gallais, Laurent; Chériaux, Gilles; Mouricaud, Daniel

    2017-01-01

    In order to transport multi-petawatt (PW) femtosecond laser beams with large spectral bandwidth, specific mirrors have to be designed and manufactured. We report on an experimental study of the laser-damage resistance and other optical properties of coating materials deposited in a 1-m class coating chamber. The study is conducted on single-layer coatings deposited by electron beam evaporation at 500 fs. Based on the experience of large optics for nanosecond applications, hafnia and silica are particularly investigated. However, in the case of sub-15 fs, the spectral specifications for PW beam transport mirrors cannot be reached by classical high laser-resistant quarter-wave SiO2/HfO2 stacks. Therefore, we investigate the laser resistance of different dielectrics of interest deposited with electron-beam processes: Al2O3, Y2O3, Sc2O3, HfO2, Ta2O5, TiO2. The influence of multiple pulse irradiations and environmental conditions, such as vacuum and temperature, is studied. With the investigation of multilayer stacks, we also show that there is no difference in behavior when a film is studied as a single layer or embedded in a stack. Based on these results, we were able to optimize high reflective (>99.5%), broadband (300 nm) and high laser-induced damage threshold (2.5 J/cm2) mirrors for PW applications.

  3. Probing the interaction between two microspheres in a single Gaussian beam optical trap

    NASA Astrophysics Data System (ADS)

    Parthasarathi, Praveen; Iyengar, Shruthi Subhash; Lakkegowda, Yogesha; Bhattacharya, Sarbari; Ananthamurthy, Sharath

    2016-09-01

    Interactions between trapped microspheres have been studied in two geometries so far: (i) using line optical tweezers and (ii) in traps using two counter propagating laser beams. In both trap geometries, the stable inter bead separations have been attributed to optical binding. One could also trap two such beads in a single beam Gaussian laser trap. While there are reports that address this configuration through theoretical or simulation based treatments, there has so far been no detailed experimental work that measures the interactions. In this work, we have recorded simultaneously the fluctuation spectra of two beads trapped along the laser propagation direction in a single Gaussian beam trap by measuring the back scattered signal from the trapping and a tracking laser beam that are counter propagating . The backscattering from the trapping laser monitors the bead encountered earlier in the propagation path. The counter propagating tracking laser, on the other hand, is used to monitor the fluctuations of the second bead. Detection is by using quadrant photo detectors placed at either end. The autocorrelation functions of both beads reveal marked departures from that obtained when there is only one bead in the trap. Moreover, the fall-off profiles of the autocorrelation indicates the presence of more than one relaxation time. This indicates a method of detecting the presence of a second bead in a trap without directly carrying out measurements on it. Further, a careful analysis of the relaxation times could also reveal the nature of interactions between the beads.

  4. Nanopatterning of optical surfaces during low-energy ion beam sputtering

    NASA Astrophysics Data System (ADS)

    Liao, Wenlin; Dai, Yifan; Xie, Xuhui

    2014-06-01

    Ion beam figuring (IBF) provides a highly deterministic method for high-precision optical surface fabrication, whereas ion-induced microscopic morphology evolution would occur on surfaces. Consequently, the fabrication specification for surface smoothness must be seriously considered during the IBF process. In this work, low-energy ion nanopatterning of our frequently used optical material surfaces is investigated to discuss the manufacturability of an ultrasmooth surface. The research results indicate that ion beam sputtering (IBS) can directly smooth some amorphous or amorphizable material surfaces, such as fused silica, Si, and ULE under appropriate processing conditions. However, for IBS of a Zerodur surface, preferential sputtering together with curvature-dependent sputtering overcome ion-induced smoothing mechanisms, leading to the granular nanopatterns' formation and the coarsening of the surface. Furthermore, the material property difference at microscopic scales and the continuous impurity incorporation would affect the ion beam smoothing of optical surfaces. Overall, IBS can be used as a promising technique for ultrasmooth surface fabrication, which strongly depends on processing conditions and material characters.

  5. Inspection of commercial optical devices for data storage using a three Gaussian beam microscope interferometer

    SciTech Connect

    Flores, J. Mauricio; Cywiak, Moises; Servin, Manuel; Juarez P, Lorenzo

    2008-09-20

    Recently, an interferometric profilometer based on the heterodyning of three Gaussian beams has been reported. This microscope interferometer, called a three Gaussian beam interferometer, has been used to profile high quality optical surfaces that exhibit constant reflectivity with high vertical resolution and lateral resolution near {lambda}. We report the use of this interferometer to measure the profiles of two commercially available optical surfaces for data storage, namely, the compact disk (CD-R) and the digital versatile disk (DVD-R). We include experimental results from a one-dimensional radial scan of these devices without data marks. The measurements are taken by placing the devices with the polycarbonate surface facing the probe beam of the interferometer. This microscope interferometer is unique when compared with other optical measuring instruments because it uses narrowband detection, filters out undesirable noisy signals, and because the amplitude of the output voltage signal is basically proportional to the local vertical height of the surface under test, thus detecting with high sensitivity. We show that the resulting profiles, measured with this interferometer across the polycarbonate layer, provide valuable information about the track profiles, making this interferometer a suitable tool for quality control of surface storage devices.

  6. Fast beam steering with full polarization control using a galvanometric optical scanner and polarization controller.

    PubMed

    Jofre, M; Anzolin, G; Steinlechner, F; Oliverio, N; Torres, J P; Pruneri, V; Mitchell, M W

    2012-05-21

    Optical beam steering is a key element in many industrial and scientific applications like in material processing, information technologies, medical imaging and laser display. Even though galvanometer-based scanners offer flexibility, speed and accuracy at a relatively low cost, they still lack the necessary control over the polarization required for certain applications. We report on the development of a polarization steerable system assembled with a fiber polarization controller and a galvanometric scanner, both controlled by a digital signal processor board. The system implements control of the polarization decoupled from the pointing direction through a feed-forward control scheme. This enables to direct optical beams to a desired direction without affecting its initial polarization state. When considering the full working field of view, we are able to compensate polarization angle errors larger than 0.2 rad, in a temporal window of less than ∼ 20 ms. Given the unification of components to fully control any polarization state while steering an optical beam, the proposed system is potentially integrable and robust.

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

    SciTech Connect

    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. Inspection of commercial optical devices for data storage using a three Gaussian beam microscope interferometer.

    PubMed

    Flores, J Mauricio; Cywiak, Moisés; Servín, Manuel; Juárez, Lorenzo

    2008-09-20

    Recently, an interferometric profilometer based on the heterodyning of three Gaussian beams has been reported. This microscope interferometer, called a three Gaussian beam interferometer, has been used to profile high quality optical surfaces that exhibit constant reflectivity with high vertical resolution and lateral resolution near lambda. We report the use of this interferometer to measure the profiles of two commercially available optical surfaces for data storage, namely, the compact disk (CD-R) and the digital versatile disk (DVD-R). We include experimental results from a one-dimensional radial scan of these devices without data marks. The measurements are taken by placing the devices with the polycarbonate surface facing the probe beam of the interferometer. This microscope interferometer is unique when compared with other optical measuring instruments because it uses narrowband detection, filters out undesirable noisy signals, and because the amplitude of the output voltage signal is basically proportional to the local vertical height of the surface under test, thus detecting with high sensitivity. We show that the resulting profiles, measured with this interferometer across the polycarbonate layer, provide valuable information about the track profiles, making this interferometer a suitable tool for quality control of surface storage devices.

  9. Combined polarizing interferometer and optical beam deflection system for MEMS characterization

    NASA Astrophysics Data System (ADS)

    Jenkins, David F. L.; Clegg, Warwick W.; Liu, Xinqun; Tunstall, Glen; Cattan, Eric; Remiens, Denis; Liu, B.

    2001-12-01

    A potential application for ferroelectric thin films is micro positioning and actuation, as in MEMS devices. The amount of actuation possible is determined by a number of factors: the piezoelectric coefficient d31, geometric factors and the compliance of both the actuator and cantilever and the electric field across the film. It is important for their realization as devices in applications that these micro-actuators are characterized. One such means is to use optical beam deflection (OBD). However, whilst extremely simple to implement, optical beam deflection does not provide an absolute measure of displacement. For absolute displacement measurement, with directional determination, a dual-beam normal incidence polarization interferometer is required. Based upon an interferometer developed in our laboratory to measure the flying height or head-disk spacing in a hard disk drive, an optical system is proposed which enables both an OBD and a polarization interferometer to be combined in one compact system. Details of both systems and are presented and the combined system described.

  10. Fiber coupling and field mixing of coherent free-space optical beams in satellite communications

    NASA Astrophysics Data System (ADS)

    Poliak, J.; Giggenbach, D.; Mata Calvo, R.; Bok, D.

    2016-03-01

    Effective coupling of the optical field from free-space to optical fiber is an essential prerequisite for modern free-space optical communications systems. It allows for easier system integration with active and passive optical fiber-coupled components as well as for efficient optical field mixing for coherent communications. While coupling into single-mode fiber provides the advantage of using low-noise erbium-doped fiber preamplifiers, its relatively small mode field diameter limits achievable fiber coupling efficiency. Coupling into multimode fiber (MMF) increases the fiber coupling efficiency while introducing other spurious effects the authors have set out to analyze. The study of free-space optical beam coupling in the context of satellite communications will be presented. Here, we assume satellite link scenarios with different elevations, which correspond to different index-of-refraction turbulence (IRT) conditions. IRT gives rise to both intensity and phase aberration of the received optical field, which then causes extended speckle patterns in the focus of the receiver telescope. The speckle field at the fiber input is calculated by means of Fourier transform of the received field. Using dedicated modelling software, study of the fiber coupling efficiency, polarization preservation and high-order mode coupling in different multi-mode fibers is carried out.

  11. Radiation optic neuropathy after megavoltage external-beam irradiation: Analysis of time-dose factors

    SciTech Connect

    Parsons, J.T.; Bova, F.J.; Million, R.R.

    1994-11-15

    To investigate the risk of radiation-induced optic neuropathy according to total radiotherapy dose and fraction size, based on both retrospective and prospectively collected data. Between October 1964 and May 1989, 215 optic nerves in 131 patients received fractionated external-beam irradiation during the treatment of primary extracranial head and neck tumors. All patients had a minimum of 3 years of ophthalmologic follow-up (range, 3 to 21 years). The clinical end point was visual acuity of 20/100 or worse as a result of optic nerve injury. Anterior ischemic optic neuropathy developed in five nerves (at mean and median times of 32 and 30 months, respectively, and a range of 2-4 years). Retrobulbar optic neuropathy developed in 12 nerves (at mean and median times of 47 and 28 months, respectively, and a range of 1-14 years). No injuries were observed in 106 optic nerves that received a total dose of <59 Gy. Among nerves that received doses of {ge} 60 Gy, the dose per fraction was more important than the total dose in producing optic neuropathy. The 15-year actuarial risk of optic compared with 47% when given in fraction sizes {ge}1.9 Gy. The data also suggest an increased risk of optic nerve injury with increasing age. As there is no effective treatment of radiation-induced optic neuropathy, efforts should be directed at its prevention by minimizing the total dose, paying attention to the dose per fraction to the nerve, and using reduced field techniques where appropriate to limit the volume of tissues that receive high-dose irradiation. 32 refs., 5 figs., 5 tabs.

  12. Push beam spot-size dependence of atom transfer in a double magneto-optical trap setup.

    PubMed

    Ram, S P; Tiwari, S K; Mishra, S R; Rawat, H S

    2013-07-01

    We have studied the dependence of atom transfer between two magneto-optical traps (MOTs) on the spot-size of a push laser beam in a double magneto-optical trap setup. It was observed that the spot-size of the push beam at vapor-chamber MOT (VC-MOT) affects significantly the transfer of atoms from the VC-MOT to an ultrahigh vacuum MOT (UHV-MOT). The number of atoms accumulated in the UHV-MOT first increases with the push beam spot-size and then decreases with it after attaining a maximum value, for a given power of the push beam. Our results show that the number of atoms accumulated in the UHV-MOT is dependent on the push beam spot-size, push beam power, and capture speed of the UHV-MOT.

  13. Adaptive optical beam shaping for compensating projection-induced focus deformation

    NASA Astrophysics Data System (ADS)

    Pütsch, Oliver; Stollenwerk, Jochen; Loosen, Peter

    2016-02-01

    Scanner-based applications are already widely used for the processing of surfaces, as they allow for highly dynamic deflection of the laser beam. Particularly, the processing of three-dimensional surfaces with laser radiation initiates the development of highly innovative manufacturing techniques. Unfortunately, the focused laser beam suffers from deformation caused by the involved projection mechanisms. The degree of deformation is field variant and depends on both the surface geometry and the working position of the laser beam. Depending on the process sensitivity, the deformation affects the process quality, which motivates a method of compensation. Current approaches are based on a local adaption of the laser power to maintain constant intensity within the interaction zone. For advanced manufacturing, this approach is insufficient, as the residual deformation of the initial circular laser spot is not taken into account. In this paper, an alternative approach is discussed. Additional beam-shaping devices are integrated between the laser source and the scanner, and allow for an in situ compensation to ensure a field-invariant circular focus spot within the interaction zone. Beyond the optical design, the approach is challenging with respect to the control theory's point of view, as both the beam deflection and the compensation have to be synchronized.

  14. FreeCAD visualization of realistic 3D physical optics beams within a CAD system-model

    NASA Astrophysics Data System (ADS)

    Gayer, D.; O'Sullivan, C.; Scully, S.; Burke, D.; Brossard, J.; Chapron, C.

    2016-07-01

    The facility to realise the shape and extent of optical beams within a telescope or beamcombiner can aid greatly in the design and layout of optical elements within the system. It can also greatly facilitate communication between the optical design team and other teams working on the mechanical design of an instrument. Beyond the realm where raytracing is applicable however, it becomes much more difficult to realise accurate 3D beams which incorporate diffraction effects. It then is another issue to incorporate this into a CAD model of the system. A novel method is proposed which has been used to aid with the design of an optical beam combiner for the QUBIC (Q and U Bolometric Interferometer for Cosmology) 1 experiment operating at 150 GHz and 220 GHz. The method combines calculation work in GRASP 2, a commercial physical optics modelling tool from TICRA, geometrical work in Mathematica, and post processing in MATLAB. Finally, the Python console of the open source package FreeCAD3 is exploited to realise the 3D beams in a complete CAD system-model of the QUBIC optical beam combiner. This paper details and explains the work carried out to reach the goal and presents some graphics of the outcome. 3D representations of beams from some back-to-back input horns of the QUBIC instrument are shown within the CAD model. Beams of the -3dB and -13dB contour envelope are shown as well as envelopes enclosing 80% and 95% of the power of the beam. The ability to see these beams in situ with all the other elements of the combiner such as mirrors, cold stop, beam splitter and cryostat widows etc. greatly simplified the design for these elements and facilitated communication of element dimension and location between different subgroups within the QUBIC group.

  15. Beam position controlling method for 3D optical system and its application in non-planar ring resonators.

    PubMed

    Yuan, Jie; Chen, Meixiong; Long, Xingwu; Tan, Yanyang; Kang, Zhenglong; Li, Yingying

    2012-08-13

    A novel theoretical beam position controlling method for 3D optical system has been proposed in this paper. Non-planar ring resonator, which is a typical 3D optical system, has been chosen as an example to show its application. To the best of our knowledge, the generalized ray matrices, augmented 5 × 5 ray matrices for paraxial dielectric interface transmission and paraxial optical-wedge transmission, and their detailed deducing process have been proposed in this paper for the first time. By utilizing the novel coordinate system for Gaussian beam reflection and the generalized ray matrix of paraxial optical-wedge transmission, the rules and some novel results of the optical-axis perturbations of non-planar ring resonators have been obtained. Wedge angle-induced mismatching errors of non-planar ring resonators have been found out and two experimental beam position controlling methods to effectively eliminate the wedge angle-induced mismatching errors have been proposed. All those results have been confirmed by related alignment experiments and the experimental results have been described with diagrammatic representation. These findings are important to the beam control, cavity design, and cavity alignment of high precision non-planar ring laser gyroscopes. Those generalized ray matrices and their deducing methods are valuable for ray analysis of various kinds of paraxial optical-elements and resonators. This novel theoretical beam position controlling method for 3D optical system is valuable for the controlling of various kinds of 3D optical systems.

  16. A new generation of IC based beam steering devices for free-space optical communication

    NASA Astrophysics Data System (ADS)

    Bedi, Vijit

    Free Space Optical (FSO) communication has tremendously advanced within the last decade to meet the ever increasing demand for higher communication bandwidth. Advancement in laser technology since its invention in the 1960's [1] attracted them to be the dominant source in FSO communication modules. The future of FSO systems lay in implementing semiconductor lasers due to their small size, power efficiency and mass fabrication abilities. In the near future, these systems are very likely to be used in space and ground based applications and revolutionary beam steering technologies will be required for distant communications in free-space. The highly directional characteristic inherent to a laser beam challenges and calls for new beam pointing and steering technologies for such type of communication. In this dissertation, research is done on a novel FSO communication device based on semiconductor lasers for high bandwidth communication. The "Fly eye transceiver" is an extremely wide steering bandwidth, completely non-mechanical FSO laser communication device primarily designed to replace traditional mechanical beam steering optical systems. This non-mechanical FSO device possesses a full spherical steering range and a very high tracking bandwidth. Inspired by the evolutionary model of a fly's eye, the full spherical steering range is assured by electronically controlled switching of its sub-eyes. Non mechanical technologies used in the past for beam steering such as acousto-optic Bragg cells, liquid crystal arrays or piezoelectric elements offer the wide steering bandwidth and fast response time, but are limited in their angular steering range. Mechanical gimbals offer a much greater steering range but face a much slower response time or steering bandwidth problem and often require intelligent adaptive controls with bulky driver amplifiers to feed their actuators. As a solution to feed both the fast and full spherical steering, the Fly-eye transceiver is studied as

  17. An etched fiber optic vibration sensor to monitor the simply supported beam

    NASA Astrophysics Data System (ADS)

    Putha, Kishore; Dinakar, Dantala; Rao, Pachava V.; Sengupta, Dipankar; Srimannarayana, K.; Sai Shankar, M.

    2012-04-01

    A single mode fiber optic vibration senor is designed and demonstrated to monitor the vibration of a simply supported beam. A rectangular beam (length 30.8 cm, width 2.5cm and thickness 0.5mm) made of spring-steel is arranged as simply supported beam and is made to vibrate periodically. To sense the vibrations a telecommunication fiber is chemically etched such that its diameter reaches 50μm and is glued using an epoxy at the centre of the beam. A broadband light (1550nm) is launched into Fiber Bragg Grating (FBG) through a circulator. The light reflected by the FBG (1540.32nm) is coupled into the centre etched fibre through the circulator and is detected by photodiode connected to a transimpedance amplifier. The electrical signal is logged into the computer through NI-6016 DAQ. The sensor works on transmission power loss due to the mode volume mismatch and flexural strain (field strength) of the fiber due to the bending in the fiber with respect to the bending of the spring-steel beam. The beam is made to vibrate and the corresponding intensity of light is recorded. Fast Fourier transform (FFT) technique is used to measure the frequencies of vibration. The results show that this sensor can sense vibration of low frequency accurately and repeatability is high. The sensor has high linear response to axial displacement of about 0.8 mm with sensitivity of 32mV/10μm strain. This lowcost sensor may find a place in industry to monitor the vibrations of the beam structures and bridges.

  18. A novel differential optical beam deflection detection system for measuring laser-generated surface acoustic waves

    NASA Astrophysics Data System (ADS)

    Shi, Yifei; Shen, Zhonghua; Ni, Xiaowu; Lu, Jian

    2008-03-01

    As the application of the laser ultrasonics developed rapidly, there is especial call for more sensitive and convenient optical installation to detect the ultrasonic waves induced by pulsed laser. The optical beam deflection (OBD) methods have abstracted the interest of people for many years for their merits over the interference method. In this paper a novel differential OBD detection system for measuring laser-generated surface acoustic waves (SAW) is presented. The detection principle of this optical system is discussed in detail according to the scheme. And we get the linear relation between the physical parameter of the SAW and the output of the detection system. For confirm the conclusion the Monte Carlo computation method is utilized to simulate the ray propagation in the system, adding the consideration of the light spot distribution of the detection laser. The numerical result agrees with the analytic method. The linear relation between the detection system output current and the deflection angle induced by SAW is validated. Furthermore, the sensitivity and the spatial resolution of the system proposed are also calculated for comparing with the other OBD methods. The results show that this differential optical beam deflection detection system is more sensitive to the small disturbance and has higher space resolution. It has considerable potential in ultrasonic measurement.

  19. Study on power coupling of annular vortex beam propagating through a two-Cassegrain-telescope optical system in turbulent atmosphere.

    PubMed

    Wu, Huiyun; Sheng, Shen; Huang, Zhisong; Zhao, Siqing; Wang, Hua; Sun, Zhenhai; Xu, Xiegu

    2013-02-25

    As a new attractive application of the vortex beams, power coupling of annular vortex beam propagating through a two- Cassegrain-telescope optical system in turbulent atmosphere has been investigated. A typical model of annular vortex beam propagating through a two-Cassegrain-telescope optical system is established, the general analytical expression of vortex beams with limited apertures and the analytical formulas for the average intensity distribution at the receiver plane are derived. Under the H-V 5/7 turbulence model, the average intensity distribution at the receiver plane and power coupling efficiency of the optical system are numerically calculated, and the influences of the optical topological charge, the laser wavelength, the propagation path and the receiver apertures on the power coupling efficiency are analyzed. These studies reveal that the average intensity distribution at the receiver plane presents a central dark hollow profile, which is suitable for power coupling by the Cassegrain telescope receiver. In the optical system with optimized parameters, power coupling efficiency can keep in high values with the increase of the propagation distance. Under the atmospheric turbulent conditions, great advantages of vortex beam in power coupling of the two-Cassegrain-telescope optical system are shown in comparison with beam without vortex.

  20. Effects of Optical Loss Factors on Heliostat Field Layout for Beam-Down Solar Concentrating Systems

    NASA Astrophysics Data System (ADS)

    Utamura, Motoaki; Takamatsu, Tadahiko; Yuasa, Minoru; Kajita, Rina; Yamamoto, Takashi

    A methodology to give an optimal layout of a group of heliostats has been developed for beam-down concentrating solar tower systems. Given the maximum solar power together with optical parameters, the method determines an optimal configuration of a heliostat field around a tower. Various optical losses such as cosine factor, shadowing and blocking at heliostats are considered in the calculation. Furthermore, spillage at the receiver is taken into account due to the spread of light caused by the effects of a finite solar disk, flat facet and various stochastic errors in optical hardware and control. It is found the effect of spillage becomes significant at heliostats from the tower at the distance farther than four times of upper focus height of the reflector when receiver diameter is one fifteenth of the height and dominates the configuration of the optimal heliostat layout.