Science.gov

Sample records for beam steering systems

  1. 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.

  2. Holographic memory using beam steering

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin (Inventor); Hanan, Jay C. (Inventor); Reyes, George F. (Inventor); Zhou, Hanying (Inventor)

    2007-01-01

    A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.

  3. Holographic memory using beam steering

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin (Inventor); Hanan, Jay C. (Inventor); Reyes, George F. (Inventor); Zhou, Hanying (Inventor)

    2006-01-01

    A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) or Micro-Electro-Mechanical Systems (MEMS) mirrors steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.

  4. Laser beam steering device

    NASA Technical Reports Server (NTRS)

    Motamedi, M. E.; Andrews, A. P.; Gunning, W. J.

    1993-01-01

    Agile beam steering is a critical requirement for airborne and space based LIDAR and optical communication systems. Design and test results are presented for a compact beam steering device with low inertia which functions by dithering two complementary (positive and negative) binary optic microlens arrays relative to each other in directions orthogonal to the direction of light propagation. The miniaturized system has been demonstrated at scan frequencies as high as 300 Hz, generating a 13 x 13 spot array with a total field of view of 2.4 degrees. The design is readily extendable to a 9.5 degree field of view and a 52 x 52 scan pattern. The system is compact - less than 2 in. on a side. Further size reductions are anticipated.

  5. MEMS-based beam steering system for individual addressing of trapped ions

    NASA Astrophysics Data System (ADS)

    Kim, Taehyun; Knoernschild, Caleb; Mount, Emily; Crain, Stephen; Noek, Rachel; Gaultney, Daniel; van Rynbach, Andre; Maunz, Peter; Kim, Jungsang

    2011-05-01

    One of the important components to implement large-scale trapped ion quantum information processing is a scalable technology to manipulate individual ions in a long linear chain of ions. So far, individual addressing has been demonstrated by steering a focused laser beam on individual ions with acousto-optic and electro-optic deflectors, by utilizing the Zeeman shift due to a magnetic field gradient, and by separating a single ion from the rest of the chain for individual exposure to laser light. Micro-mirrors based on microelectromechanical system (MEMS) technology can be used to design an alternative beam steering system which can handle multiple beams with different wavelengths and address locations in multiple dimensions. We will report our progress in integrating a MEMS beam steering system with an Yb ion trap experiment. Our MEMS system is designed to steer an ultraviolet beam with a waist of ~1.5 μm across a 20 μm range. To demonstrate the individual addressing capability, we plan to measure the Ramsey interference of the differential AC Stark shift induced by an individually-focused, far-detuned laser beam.

  6. High-gradient microelectromechanical system quadrupole electromagnets for particle beam focusing and steering

    NASA Astrophysics Data System (ADS)

    Harrison, Jere; Hwang, Yongha; Paydar, Omeed; Wu, Jimmy; Threlkeld, Evan; Rosenzweig, James; Musumeci, Pietro; Candler, Rob

    2015-02-01

    Recent advancements in microelectromechanical system (MEMS) fabrication techniques have enabled the batch-fabrication of quadrupole MEMS electromagnets producing 100 mT-scale field across sub-mm gaps with the potential for transformational advances in the field of compact high performance charged particle focusing and steering optics. The footprint of these in-vacuum focusing and steering optics can be as small as 3 mm ×3 mm ×0.5 mm . The low electromagnet impedance (58 m Ω , 32 nH per pole) facilitates power-efficient operation and continuous or low duty cycle operation, and the individually controlled electromagnets allow combined dipole-quadrupole fields. Here we report on an experiment where these miniature devices have been used to focus and steer a 34 keV electron beam from a DC photogun, demonstrating the first application of magnetic MEMS to particle beam focusing.

  7. Third-order theory of the Risley-prism-based beam steering system.

    PubMed

    Li, Yajun

    2011-02-10

    Nonparaxial ray tracing is performed to investigate the field scanned out by a single beam through two rotatable thick prisms with different parameters, and a general solution is obtained and then expanded into a power series to establish the third-order theory for Risley prisms that paves the way to investigate topics of interest such as optical distortions in the scan pattern and an analytical solution of the inverse problem of a Risley-prism-based laser beam steering system; i.e., the problem is concerned with how to direct a laser beam to any specified direction within the angular range of the system. PMID:21343989

  8. A microwave tomography system using a tunable mirror for beam steering

    SciTech Connect

    Tayebi, A.; Tang, J.; Paladhi, P. Roy; Udpa, L.; Udpa, S.

    2014-02-18

    Microwave tomography is a fast-growing technique in the fields of NDE and medical industry. This paper presents a new microwave tomography system which reduces the complexities of conventional microwave imaging systems by utilizing a reconfigurable mirror, a tunable reflectarray antenna. In order to build a tunable reflectarray with beam steering capabilities, the unit cell characteristics should dynamically alter. Modelling and experimental results of a single unit cell are presented in this work.

  9. More About Beam-Steering Subsystem For Laser Communication

    NASA Technical Reports Server (NTRS)

    Page, Norman A.; Chen, Chien-Chu; Hemmati, Hamid; Lesh, James R.

    1995-01-01

    Two reports present additional information about developmental beam-steering subsystem of laser-communication system. Aspects of this subsystem described previously in "Beam-Steering Subsystem for Laser Communication" (NPO-19069) and "Digital Controller for Laser-Beam-Steering Subsystem" (NPO-19193). Reports reiterate basic principles of operation of beam-steering subsystem and of laser-communication system as whole. Also presents some of details of optical and mechanical design of prototype of subsystem, called Optical Communication Demonstrator.

  10. Two-axis Beam Steering Mirror Control system for Precision Pointing and Tracking Applications

    SciTech Connect

    Ulander, K

    2006-02-08

    Precision pointing and tracking of laser beams is critical in numerous military and industrial applications. This is particularly true for systems requiring atmospheric beam propagation. Such systems are plagued by environmental influences which cause the optical signal to break up and wander. Example applications include laser communications, precision targeting, active imaging, chemical remote sensing, and laser vibrometry. The goal of this project is to build a beam steering system using a two-axis mirror to maintain precise pointing control. Ultimately, position control to 0.08% accuracy (40 {micro}rad) with a bandwidth of 200 Hz is desired. The work described encompasses evaluation of the instrumentation system and the subsequent design and implementation of an analog electronic controller for a two-axis mirror used to steer the beam. The controller operates over a wide temperature range, through multiple mirror resonances, and is independent of specific mirrors. The design was built and successfully fielded in a Lawrence Livermore National Laboratory free-space optics experiment. All measurements and performance parameters are derived from measurements made on actual hardware that was built and field tested. In some cases, specific design details have been omitted that involve proprietary information pertaining to Lawrence Livermore National Laboratory patent positions and claims. These omissions in no way impact the general validity of the work or concepts presented in this thesis.

  11. Beam Steering Devices Reduce Payload Weight

    NASA Technical Reports Server (NTRS)

    2012-01-01

    Scientists have long been able to shift the direction of a laser beam, steering it toward a target, but often the strength and focus of the light is altered. For precision applications, where the quality of the beam cannot be compromised, scientists have typically turned to mechanical steering methods, redirecting the source of the beam by swinging the entire laser apparatus toward the target. Just as the mechanical methods used for turning cars has evolved into simpler, lighter, power steering methods, so has the means by which researchers can direct lasers. Some of the typical contraptions used to redirect lasers are large and bulky, relying on steering gimbals pivoted, rotating supports to shift the device toward its intended target. These devices, some as large and awkward as a piece of heavy luggage, are subject to the same issues confronted by mechanical parts: Components rub, wear out, and get stuck. The poor reliability and bulk not to mention the power requirements to run one of the machines have made mechanical beam steering components less than ideal for use in applications where weight, bulk, and maneuverability are prime concerns, such as on an unmanned aerial vehicle (UAV) or a microscope. The solution to developing reliable, lighter weight, nonmechanical steering methods to replace the hefty steering boxes was to think outside the box, and a NASA research partner did just that by developing a new beam steering method that bends and redirects the beam, as opposed to shifting the entire apparatus. The benefits include lower power requirements, a smaller footprint, reduced weight, and better control and flexibility in steering capabilities. Such benefits are realized without sacrificing aperture size, efficiency, or scanning range, and can be applied to myriad uses: propulsion systems, structures, radiation protection systems, and landing systems.

  12. Combining the switched-beam and beam-steering capabilities in a 2-D phased array antenna system

    NASA Astrophysics Data System (ADS)

    Tsai, Yi-Che; Chen, Yin-Bing; Hwang, Ruey-Bing

    2016-01-01

    This paper presents the development, fabrication, and measurement of a novel beam-forming system consisting of 16 subarray antennas, each containing four aperture-coupled patch antennas, and the application of this system in smart wireless communication systems. The beam patterns of each of the subarray antennas can be switched toward one of nine zones over a half space by adjusting the specific phase delay angles among the four antenna elements. Furthermore, when all subarrays are pointed at the same zone, slightly continuous beam steering in around 1° increments can be achieved by dynamically altering the progressive phase delay angle among the subarrays. Phase angle calibration was implemented by coupling each transmitter output and down converter into the in-phase/quadrature baseband to calculate the correction factor to the weight. In addition, to validate the proposed concepts and the fabricated 2-D phased array antenna system, this study measured the far-field radiation patterns of the aperture-coupled patch array integrated with feeding networks and a phase-calibration system to carefully verify its spatially switched-beam and beam-steering characteristics at a center frequency of 2.4 GHz which can cover the industrial, scientific, and medical band and some long-term evolution applications. In addition, measured results were compared with calculated results, and agreement between them was observed.

  13. Steering, splitting, and cloning of an optical beam in a coherently driven Raman gain system

    NASA Astrophysics Data System (ADS)

    Verma, Onkar N.; Dey, Tarak N.

    2015-01-01

    We propose an all-optical antiwaveguide mechanism for steering, splitting, and cloning of an optical beam without diffraction. We use a spatially inhomogeneous pump beam to create an antiwaveguide structure in a Doppler broadened N -type four-level Raman gain medium for a copropagating weak probe beam. We show that a transverse modulated index of refraction and gain due to the spatially dependent pump beam hold the keys to steering, splitting, and cloning of an optical beam. We have also shown that an additional control field permits the propagation of an optical beam through an otherwise gain medium without diffraction and instability. We further discuss how finesse of the cloned images can be increased by changing the detuning of the control field. We arrive at similar results by using homogeneously broadened gain media at higher density.

  14. Pointing error analysis of Risley-prism-based beam steering system.

    PubMed

    Zhou, Yuan; Lu, Yafei; Hei, Mo; Liu, Guangcan; Fan, Dapeng

    2014-09-01

    Based on the vector form Snell's law, ray tracing is performed to quantify the pointing errors of Risley-prism-based beam steering systems, induced by component errors, prism orientation errors, and assembly errors. Case examples are given to elucidate the pointing error distributions in the field of regard and evaluate the allowances of the error sources for a given pointing accuracy. It is found that the assembly errors of the second prism will result in more remarkable pointing errors in contrast with the first one. The pointing errors induced by prism tilt depend on the tilt direction. The allowances of bearing tilt and prism tilt are almost identical if the same pointing accuracy is planned. All conclusions can provide a theoretical foundation for practical works. PMID:25321377

  15. Individual addressing of trapped {sup 171}Yb{sup +} ion qubits using a microelectromechanical systems-based beam steering system

    SciTech Connect

    Crain, S.; Mount, E.; Baek, S.; Kim, J.

    2014-11-03

    The ability to individually manipulate the increasing number of qubits is one of the many challenges towards scalable quantum information processing with trapped ions. Using micro-mirrors fabricated with micro-electromechanical systems technology, we focus laser beams on individual ions in a linear chain and steer the focal point in two dimensions. We demonstrate sequential single qubit gates on multiple {sup 171}Yb{sup +} qubits and characterize the gate performance using quantum state tomography. Our system features negligible crosstalk to neighboring ions (<3×10{sup −4}), and switching speed comparable to typical single qubit gate times (<2 μs)

  16. Automotive power steering system

    SciTech Connect

    VanGorder, D.H.; Wilson, K.R.

    1991-04-23

    This patent describes improvement in an automotive power steering system including a pump, a servo-valve, a steering assist fluid motor, a reservoir having a reservoir chamber therein, fluid ducts; a volume of hydraulic oil; a fluid level. The improvement comprises: means defining a fill port; a cover; means connect a gas accumulator.

  17. Digital Controller For Laser-Beam-Steering Subsystem: Part 2

    NASA Technical Reports Server (NTRS)

    Ansari, Homayoon; Voisinet, Leeann

    1995-01-01

    A report presents additional information about laser-beam-steering apparatus described in "Digital Controller for Laser-Beam-Steering Subsystem" (NPO-19193) and "More About Beam-Steering Subsystem for Laser Communication" (NPO-19381). Reiterates basic principles of operation of beam-steering subsystem, with emphasis on modes of operation, basic design concepts, and initial experiments on partial prototype of apparatus.

  18. Highly sensitive beam steering with plasmonic antenna

    PubMed Central

    Rui, Guanghao; Zhan, Qiwen

    2014-01-01

    In this work, we design and study a highly sensitive beam steering device that integrates a spiral plasmonic antenna with a subwavelength metallic waveguide. The short effective wavelength of the surface plasmon polaritons (SPPs) mode supported by the metallic waveguide is exploited to dramatically miniaturize the device and improve the sensitivity of the beam steering. Through introducing a tiny displacement of feed point with respect to the geometrical center of the spiral plasmonic antenna, the direction of the radiation can be steered at considerably high angles. Simulation results show that steering angles of 8°, 17° and 34° are obtainable for a displacement of 50 nm, 100 nm and 200 nm, respectively. Benefiting from the reduced device size and the shorter SPP wavelength, the beam steering sensitivity of the beam steering is improved by 10-fold compared with the case reported previously. This miniature plasmonic beam steering device may find many potential applications in quantum optical information processing and integrated photonic circuits. PMID:25091405

  19. A computer algorithm for automatic beam steering

    SciTech Connect

    Drennan, E.

    1992-06-01

    Beam steering is done by modifying the current in a trim or bending magnet. If the current change is the right amount the beam can be made to bend in such a manner that it will hit a swic or BPM downstream from the magnet at a predetermined set point. Although both bending magnets and trim magnets can be used to modify beam angle, beam steering is usually done with trim magnets. This is so because, during beam steering the beam angle is usually modified only by a small amount which can be easily achieved with a trim magnet. Thus in this note, all steering magnets will be assumed to be trim magnets. There are two ways of monitoring beam position. One way is done using a BPM and the other is done using a swic. For simplicity, beam position monitoring in this paper will be referred to being done with a swic. Beam steering can be done manually by changing the current through a trim magnet and monitoring the position of the beam downstream from the magnet with a swic. Alternatively the beam can be positioned automatically using a computer which periodically updates the current through a specific number of trim magnets. The purpose of this note is to describe the steps involved in coming up with such a computer program. There are two main aspects to automatic beam steering. First a relationship between the beam position and the bending magnet is needed. Secondly a beamline setup of swics and trim magnets has to be chosen that will position the beam according to the desired specifications. A simple example will be looked at that will show that once a mathematical relationship between the needed change of the beam position on a swic and the change in trim currents is established, a computer could be programmed to calculate and update the trim currents.

  20. Nonmechanical beam steering using optical phased arrays

    NASA Astrophysics Data System (ADS)

    Dillon, Thomas E.; Schuetz, Christopher A.; Martin, Richard D.; Mackrides, Daniel G.; Curt, Petersen F.; Bonnett, James; Prather, Dennis W.

    2011-11-01

    Beam steering is an enabling technology for establishment of ad hoc communication links, directed energy for infrared countermeasures, and other in-theater defense applications. The development of nonmechanical beam steering techniques is driven by requirements for low size, weight, and power, and high slew rate, among others. The predominant beam steering technology currently in use relies on gimbal mounts, which are relatively large, heavy, and slow, and furthermore create drag on the airframes to which they are mounted. Nonmechanical techniques for beam steering are currently being introduced or refined, such as those based on liquid crystal spatial light modulators; however, drawbacks inherent to some of these approaches include narrow field of regard, low speed operation, and low optical efficiency. An attractive method that we explore is based on optical phased arrays, which has the potential to overcome the aforementioned issues associated with other mechanical and nonmechanical beam steering techniques. The optical array phase locks a number of coherent optical emitters in addition to applying arbitrary phase profiles across the array, thereby synthesizing beam shapes that can be steered and utilized for a diverse range of applications.

  1. MAcro-Electro-Mechanical Systems (MÆMS) based concept for microwave beam steering in reflectarray antennas

    NASA Astrophysics Data System (ADS)

    Momeni Hasan Abadi, Seyed Mohamad Amin; Booske, John H.; Behdad, Nader

    2016-08-01

    We present a new approach to perform beam steering in reflecting type apertures such as reflectarray antennas. The proposed technique exploits macro-scale mechanical movements of parts of the structure to achieve two-dimensional microwave beam steering without using any solid-state devices or phase shifters integrated within the aperture of the antenna. The principles of operation of this microwave beam steering technique are demonstrated in an aperture occupied by ground-plane-backed, sub-wavelength capacitive patches with identical dimensions. We demonstrate that by tilting the ground plane underneath the entire patch array layer, a phase shift gradient can be created over the aperture of the reflectarray that determines the direction of the radiated beam. Changing the direction and slope of this phase shift gradient on the aperture allows for performing beam steering in two dimensions using only one control parameter (i.e., tilt vector of the ground plane). A proof-of-concept prototype of the structure operating at X-band is designed, fabricated, and experimentally characterized. Experiments demonstrate that small mechanical movements of the ground plane (in the order of 0.05λ0) can be used to steer the beam direction in the ±10° in two dimensions. It is also demonstrated that this beam scanning range can be greatly enhanced to ±30° by applying this concept to the same structure when its ground plane is segmented.

  2. Compact, low power precision beam steering mirror

    NASA Astrophysics Data System (ADS)

    Deweerd, Herman

    1991-02-01

    Attention is given to a family of single-mirror two-axis beam steering systems (TABS) developed for fine pointing control of an optical beam. The requirement is to control the line of sight of the optical system on board such a platform with sufficient bandwidth to overcome the perturbations and thus maintain the laser communication link between two satellites. The armature is supported on its center of gravity on a gimble. A balanced design is achieved with the mirror and tachometer magnets on one side of the gimbal and the torque magnets on the other. A negative magnetic spring constant which compensates for the angular restraining effects of the flexure bearings without any radial stiffness consequences is incorporated.

  3. Tunable beam steering enabled by graphene metamaterials.

    PubMed

    Orazbayev, B; Beruete, M; Khromova, I

    2016-04-18

    We demonstrate tunable mid-infrared (MIR) beam steering devices based on multilayer graphene-dielectric metamaterials. The effective refractive index of such metamaterials can be manipulated by changing the chemical potential of each graphene layer. This can arbitrarily tailor the spatial distribution of the phase of the transmitted beam, providing mechanisms for active beam steering. Three different beam steerer (BS) designs are discussed: a graded-index (GRIN) graphene-based metamaterial block, an array of metallic waveguides filled with graphene-dielectric metamaterial and an array of planar waveguides created in a graphene-dielectric metamaterial block with a specific spatial profile of graphene sheets doping. The performances of the BSs are numerically analyzed, showing the tunability of the proposed designs for a wide range of output angles (up to approximately 70°). The proposed graphene-based tunable beam steering can be used in tunable transmitter/receiver modules for infrared imaging and sensing. PMID:27137318

  4. Motion control of the wedge prisms in Risley-prism-based beam steering system for precise target tracking.

    PubMed

    Zhou, Yuan; Lu, Yafei; Hei, Mo; Liu, Guangcan; Fan, Dapeng

    2013-04-20

    Two exact inverse solutions of Risley prisms have been given by previous authors, based on which we calculate the gradients of the scan field that open a way to investigate the nonlinear relationship between the slewing rate of the beam and the required angular velocities of the two wedge prisms in the Risley-prism-based beam steering system for target tracking. The limited regions and singularity point at the center and the edge of the field of regard are discussed. It is found that the maximum required rotational velocities of the two prisms for target tracking are nearly the same and are dependent on the altitude angle. The central limited region is almost independent of the prism parameters. The control singularity at the crossing center path can be avoided by switching the two solutions. PMID:23669697

  5. Beam steering at the Stanford Synchrotron Radiation Laboratory

    SciTech Connect

    Hettel, R.O.

    1983-08-01

    Instability of the vertical synchrotron beam position in the experimental lines at SSRL has motivated the continuing development of its steering control system. Recent improvements have increased its ability to compensate for long term position drift and to suppress low frequency beam oscillation induced by ground motion. A description of the new system and an analysis of its performance is presented.

  6. ICESat-2 ATLAS Beam Steering Mechanism (BSM)

    NASA Technical Reports Server (NTRS)

    Hinkle, Matthew

    2015-01-01

    This work covers the design and test of a beam steering mechanism (BSM) used to accurately guide a laser on the Advanced Topographic Laser Altimeter System (ATLAS) down to Earth in order to measure elevation. It describes the main components in the BSM that allows it to perform and meet stringent requirements. Requirements of the BSM include two-axis steering of the transmitted laser beam, +-5000 uRad mechanical motion in each axis, and 1.5 uRad RMS pointing stability among many other requirements. The BSM uses four voice coil actuators in order to locate the mirror at the angle we need. There are four Differential Position Sensors that determine the position and angle of the mirror at all times. These sensors were verified through optical testing in both ambient and thermal conditions. Testing and extensive analyses were performed on the two-axis flexure throughout the program to check flexure thickness, positive margins, and infinite life. The mirror mount design has been modified to eliminate radial preload, while incorporating a titanium wave spring to provide an axial preload of 10.8N. The BSM underwent multiple tests in order to verify all components work as required under various conditions.

  7. 49 CFR 570.7 - Steering systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 6 2010-10-01 2010-10-01 false Steering systems. 570.7 Section 570.7... Pounds or Less § 570.7 Steering systems. (a) System play. Lash or free play in the steering system shall... in the steering system. Table 1—Steering System Free Play Values Steering wheel diameter...

  8. ATLAS Beam Steering Mechanism Lessons Learned

    NASA Technical Reports Server (NTRS)

    Blumenstock, Kenneth A.; Cramer, Alexander K.; Gostin, Alan B.; Hakun, Claef F.; Haney, Paul G.; Hinkle, Matthew R.; Lee, Kenneth Y.; Lugo, Carlos F.; Matuszeski, Adam J.; Morrell, Armando; Armani, Nerses V.; Bonafede, Joseph; Jackson, Molly I.; Steigner, Peter J.; Stromsdorfer, Juan J.

    2016-01-01

    This paper describes the design, testing, and lessons learned during the development of the Advanced Topographic Laser Altimeter System (ATLAS) Beam Steering Mechanism (BSM). The BSM is a 2 degree-of-freedom tip-tilt mechanism for the purpose of pointing a flat mirror to tightly control the co-alignment of the transmitted laser and the receiver telescope of the ATLAS instrument. The high resolution needs of the mission resulted in sub-arcsecond pointing and knowledge requirements, which have been met. Development of the methodology to verify performance required significant effort. The BSM will fly as part of the Ice, Cloud, and Elevation Satellite II Mission (ICESat II), which is scheduled to be launched in 2017. The ICESat II primary mission is to map the earth's surface topography for the determination of seasonal changes of ice sheet thickness and vegetation canopy thickness to establish long-term trends.

  9. ATLAS Beam Steering Mechanism (BSM) Lessons Learned

    NASA Technical Reports Server (NTRS)

    Blumenstock, Kenneth A.; Cramer, Alexander K.; Gosten, Alan B.; Hakun, Claef F.; Haney, Paul G.; Hinkle, Matthew R.; Lee, Kenneth Y.; Lugo, Carlos F.; Matuszeski, Adam J.; Morell, Armando; Armani, Nerses V.; Bonafede, Joseph; Jackson, Molly I.; Steigner, Peter J.; Stromsdorfer, Juan J.

    2016-01-01

    This paper describes the design, testing, and lessons learned during the development of the Advanced Topographic Laser Altimeter System (ATLAS) Beam Steering Mechanism (BSM). The BSM is a 2 degree-of-freedom tip-tilt mechanism for the purpose of pointing a flat mirror to tightly control the co-alignment of the transmitted laser and the receiver telescope of the ATLAS instrument. The high resolution needs of the mission resulted in sub-arcsecond pointing and knowledge requirements, which have been met. Development of the methodology to verify performance required significant effort. The BSM will fly as part of the Ice, Cloud, and Elevation Satellite II Mission (ICESat II), which is scheduled to be launched in 2017. The ICESat II primary mission is to map the Earth's surface topography for the determination of seasonal changes of ice sheet thickness and vegetation canopy thickness to establish long-term trends.

  10. Beam Steering Mechanism (BSM) Lessons Learned

    NASA Technical Reports Server (NTRS)

    Blumenstock, Kenneth A.; Cramer, Alexander K.; Gostin, Alan B.; Hakun, Claef F.; Haney, Paul G.; Hinkle, Matthew R.; Lee, Kenneth Y.; Lugo, Carlos F.; Matuszeski, Adam J.; Morell, Armando; Armani, Nerses V.; Bonafede, Joseph; Jackson, Molly I.; Steigner, Peter J.; Stromsdorfer, Juan J.

    2016-01-01

    This paper describes the design, testing, and lessons learned during the development of the Advanced Topographic Laser Altimeter System (ATLAS) Beam Steering Mechanism (BSM). The BSM is a 2 degree-of-freedom tip-tilt mechanism for the purpose of pointing a flat mirror to tightly control the co-alignment of the transmitted laser and the receiver telescope of the ATLAS instrument. High resolution needs of the mission resulted in sub-arcsecond pointing and knowledge requirements, which have been met. Development of methodology to verify performance was a significant effortadvancement. The BSM will fly as part of the Ice, Cloud, and Elevation Satellite 2 Mission (ICESat 2), which is scheduled to be launched in 2017. The ICESat 2 primary mission is to map the earths surface topography for the determination of seasonal changes of ice sheet thickness as well as vegetation canopy thickness.

  11. Compact holographic memory using E - O beam steering

    NASA Technical Reports Server (NTRS)

    Chao, Tien-Hsin; Zhou, Hanying; Reyes, George; Hanan, Jay

    2002-01-01

    An innovative holographic memory system has been developed at JPL for high-density and high speed data storage in a space environment. This system ulitlizes a newly developed electro-optic (E-O) beam steering technology for beam steering to enable high-speed random access memory read/write without moving parts. Recently, a compact CD-sized holographic memory broadboard has been developed and demonstrated for holographic data storage adn retrieval. Detail technical progress will be presented in this paper.

  12. SPS Beam Steering for LHC Extraction

    SciTech Connect

    Gianfelice-Wendt, Eliana; Bartosik, Hannes; Cornelis, Karel; Norderhaug Drøsdal, Lene; Goddard, Brennan; Kain, Verena; Meddahi, Malika; Papaphilippou, Yannis; Wenninger, Jorg

    2014-07-01

    The CERN Super Proton Synchrotron accelerates beams for the Large Hadron Collider to 450 GeV. In addition it produces beams for fixed target facilities which adds complexity to the SPS operation. During the run 2012-2013 drifts of the extracted beam trajectories have been observed and lengthy optimizations in the transfer lines were performed to reduce particle losses in the LHC. The observed trajectory drifts are consistent with the measured SPS orbit drifts at extraction. While extensive studies are going on to understand, and possibly suppress, the source of such SPS orbit drifts the feasibility of an automatic beam steering towards a “golden” orbit at the extraction septa, by means of the interlocked correctors, is also being investigated. The challenges and constraints related to the implementation of such a correction in the SPS are described. Simulation results are presented and a possible operational steering strategy is proposed.

  13. Laser steering of particle beams: Refraction and reflection ofparticle beams

    SciTech Connect

    Esarey, Eric; Katsouleas, T.; Mori, W.B.; Dodd, E.; Lee, S.; Hemker, R.; Clayton, C.; Joshi, C.

    1999-11-01

    The co-propagation of an intense particle beam with an ionizing laser beam in a working gas/plasma is considered. When the axes of the laser and particle beam are not aligned, then asymmetric plasma lensing results in a net dipole field acting on the particle beam. The particle beam can be steered or bent (as well as focused) by steering the laser. An analogy is made between the bending of the particle beam by collective effects at a plasma boundary and the refraction or reflection of light at an interface. This mechanism of particle steering may be of interest in applications for which permanent magnets are inconvenient of a fast turn on is required. 3-D particle-in-cell simulations and relevance to a recent experiment are discussed.

  14. Image Processing In Laser-Beam-Steering Subsystem

    NASA Technical Reports Server (NTRS)

    Lesh, James R.; Ansari, Homayoon; Chen, Chien-Chung; Russell, Donald W.

    1996-01-01

    Conceptual design of image-processing circuitry developed for proposed tracking apparatus described in "Beam-Steering Subsystem For Laser Communication" (NPO-19069). In proposed system, desired frame rate achieved by "windowed" readout scheme in which only pixels containing and surrounding two spots read out and others skipped without being read. Image data processed rapidly and efficiently to achieve high frequency response.

  15. Digital Controller For Laser-Beam-Steering Subsystem

    NASA Technical Reports Server (NTRS)

    Ansari, Homayoon

    1995-01-01

    Report presents additional information about proposed apparatus described in "Beam-Steering Subsystem for Laser Communication" (NPO-19069). Discusses design of digital beam-steering control subsystem and, in particular, that part of design pertaining to digital compensation for frequency response of steering mirror.

  16. Dynamic two-dimensional beam-pattern steering technique

    NASA Technical Reports Server (NTRS)

    Zhou, Shaomin; Yeh, Pochi; Liu, Hua-Kuang

    1993-01-01

    A dynamic two-dimensional laser-beam-pattern steering technique using photorefractive holograms in conjunction with electrically addressed spatial light modulators is proposed and investigated. The experimental results demonstrate the dynamic steering of random combinations of basis beam patterns. The proposed method has the advantages of random beam-pattern combination, good beam intensity uniformity, and higher diffraction efficiency compared with conventional methods.

  17. Steering electromagnetic beams with conical curvature singularities.

    PubMed

    Zhang, Yong-Liang; Dong, Xian-Zi; Zheng, Mei-Ling; Zhao, Zhen-Sheng; Duan, Xuan-Ming

    2015-10-15

    We describe how the transformation-optics technique can be used to design an effective medium mimicking the conical curvature singularity. Anholonomic coordinate transformation gives rise to linear topological defects that break the rotational symmetry. The bending and splitting of the optical beams are found analytically and numerically, depending on the incident direction and the topological charge. Beyond their practical applications to omnidirectional beam steering for photonics, our findings set forth an attractive realm to simulate the relevant physical phenomena in the optical laboratory. PMID:26469619

  18. Closed form analytical inverse solutions for Risley-prism-based beam steering systems in different configurations.

    PubMed

    Li, Yajun

    2011-08-01

    Nonparaxial ray tracing through Risley prisms of four different configurations is performed to give the exact solution of the inverse problem arisen from applications of Risley prisms to free space communications. Predictions of the exact solution and the third-order theory [Appl. Opt. 50, 679 (2011)] are compared and results are shown by curves for systems using prisms of different materials. The exact solution for the problem of precision pointing is generalized to investigate the synthesis of the scan pattern, i.e., to create a desirable scan pattern on some plane perpendicular to the optical axis of the system by controlling the circular motion of the two prisms. PMID:21833103

  19. Beam steering in the SLC linac

    SciTech Connect

    Sheppard, J.C.; Lee, M.J.; Ross, M.C.; Seeman, J.T.; Stiening, R.F.; Woodley, M.D.

    1985-02-01

    In order to control emittance growth due to transverse wakefields it will be necessary to transport electrons and positrons through the Stanford Linear Collider (SLC) linac to within a hundred ..mu..m of the centers of the linac irises. Beam centering will be accomplished using computer routines to read stripline beam position monitors and in turn correct the orbits with dipole magnets. Several different steering algorithms have been investigated using electrons in the first third of the SLC linac lattice. The most promising scheme is a cascade of modified ''three-bumps'' in conjunction with long spanning harmonic corrections. General features of the orbit correcting software are discussed along with the mathematical recipes for correction. Experimental results and a discussion of future plans are presented.

  20. Beam steering in the SLC linac

    SciTech Connect

    Sheppard, J.C.; Lee, M.J.; Ross, M.C.; Seeman, J.T.; Stiening, R.F.; Woodley, M.D.

    1985-10-01

    In order to control emittance growth due to transverse wakefields it will be necessary to transport electrons and positrons through the Stanford Linear Collider (SLC) linac to within a hundred ..mu..m of the centers of the linac irises. Beam centering will be accomplished using computer routines to read stripline beam position monitors and in turn correct the orbits with dipole magnets. Several different steering algorithms have been investigated using electrons in the first third of the SLC linac lattice. The most promising scheme is a cascade of modified ''three-bumps'' in conjunction with long spanning harmonic corrections. General features of the orbit correcting software are discussed along with the mathematical recipes for correction. Experimental results and a discussion of future plans are presented.

  1. Phase shifter for antenna beam steering

    NASA Astrophysics Data System (ADS)

    Jindal, Ravi; Razban, Tchanguiz

    2016-03-01

    Wide band Array Antenna operates in Ku-band (10.7-12.7 GHz) frequency composed of N×N radiating elements. This antenna aims at the reception of television satellite signals. The goal of this research is to provide better possibility of electronic beam control instead of manual or mechanical control, and design compact and low cost phase shifters to be inserted in the feeding network of this antenna. The electronic control of the phase shifter will allow the control of beam steering. The emphasis of this project will be done at the beginning on the design of a good phase shifter in Ku band. The aim of this research is to define, simulate, release and measure a continuous phase shifter. Better reflection loss, low transmission loss, low Cost of array antennas, large range of phase-shifter, phase flatness and bandwidth will be achieved by providing better gain.

  2. Ka-Band Beam Steering Reflectarray Study

    NASA Technical Reports Server (NTRS)

    McSpadden, James O.; Fan, Lu; Chang, Kai; Huang, John

    1999-01-01

    A one-meter diameter, 32 GHz active microstrip reflectarray capable of electronic beam steering has been studied. The 15_500 element array consists of rnicrostrip patch antennas, microstrip phase shifters, and dc bias lines. Specifically, the study focused on the solid-state devices and dc bias layouts for scanning the beam linearly 45 from boresight using 2-bit phase shifters. Three configurations are recommended for the reflectarray with integrated 2-bit phase shifters where the total substrate and cladding mass varies from 8 kg to 14 kg. Additionally, dc power requirements for p-i-n diodes in 1-bit, 2-bit and 3-bit phase shifting circuits are approximately 19 W, 19 W, and 39 W, respectively. The dc power requirement for phase shifters using passive MESFETs is much less than 1 W.

  3. Missile and aircraft field test data acquired with the rapid optical beam steering (ROBS) sensor system

    NASA Astrophysics Data System (ADS)

    MacDonald, Bruce; Dunn, Murray; Herr, David W.; Hyman, Howard; Leslie, Daniel H.; Lovern, Michael G.

    1997-08-01

    The ROBS instrument has recently acquired unique imagery of a missile intercepting an airborne drone target. We present a summary of that mission. We also present imagery of three airborne targets collected while the ROBS instrument simultaneously tracked all three aircraft. The recent test data highlights the capability of the ROBS instrument for autonomous acquisition, tracking, and imaging of multiple targets under field test conditions. We also describe improvements to the optical system currently underway.

  4. Modeling and simulation of the beam steering unit

    NASA Astrophysics Data System (ADS)

    Feng, Jiayun; Li, Xiaoping; He, Xin; Wang, Jinchun

    2015-03-01

    Production lithography is undergoing a technology shift, and the requirements of beam delivery system (BDS) are increasing which also raises the precision requirements of the beam steering units (BSU) in BDS. In essence, the BSU is a two rotational degree of freedom platform. In this paper, a BSU based on 3-RPS flexure parallel mechanism is proposed. By analyzing the relationship between the unit's dimensions and mechanics, a mathematical model is built. Then the BSU with a balance between lower stress of the flexure hinges and higher accuracy of the unit can be got by optimizing the dimensions with the mathematical model. Finally a simulation is conducted to verify the design.

  5. Data transfer through beam steering using agile lensing

    NASA Astrophysics Data System (ADS)

    Arshad, Muhammad Assad; Reza, Syed Azer; Muhammad, Ahsan

    2016-04-01

    This paper presents a data transfer scheme using multi-focus tunable lenses. The design involves the use of a standard laser source and a variable focus agile lens to steer to the laser beam that passes through the lens. In our proposed system, the beam steer angle depends on an input electrical signal which drives the tunable lens. Therefore the beam steer angle is made to follow the variations in the input electrical drive signal. This is extremely interesting for data transfer applications as the data signal can be used as the input drive signal to the lens. The laser beam is steered according to the input data voltage levels and when the beam is incident on a photo-detector of a finite size, only a fraction of its total incident optical power is received by the photo-detector. This power contribution is proportional to the fraction of the total number of photons per unit area which are incident on the active area of the detector. The remaining photons which are not incident on the photo-detector do not contribute to the received power at the photo-detector. We present the theory of beam steering through a tunable lens and present a theoretical framework which governs data transfer through the proposed method. We also present the transfer function of the proposed system which helps us to calculate its essential theoretical performance parameters such as modulation depth and bit error rates. We also present experimental results to demonstrate efficient data transfer through the proposed method. As tunable lenses are primarily deployed in motion-free multi-focus cameras hence most of the modern portable devices such as cellphones and tablets use these lenses to operate the in-built variable focus cameras that are part of these devices. Because tunable lenses are commonly present in several different portable devices, the proposed method of data transfer between two devices is highly promising as it expands the use of the already deployed tunable lenses with

  6. Neutral particle beam sensing and steering

    DOEpatents

    Maier, II, William B.; Cobb, Donald D.; Robiscoe, Richard T.

    1991-01-01

    The direction of a neutral particle beam (NPB) is determined by detecting Ly.alpha. radiation emitted during motional quenching of excited H(2S) atoms in the beam during movement of the atoms through a magnetic field. At least one detector is placed adjacent the beam exit to define an optical axis that intercepts the beam at a viewing angle to include a volume generating a selected number of photons for detection. The detection system includes a lens having an area that is small relative to the NPB area and a pixel array located in the focal plane of the lens. The lens viewing angle and area pixel array are selected to optimize the beam tilt sensitivity. In one embodiment, two detectors are placed coplanar with the beam axis to generate a difference signal that is insensitive to beam variations other than beam tilt.

  7. Laser Beam Steering/shaping for Free Space Optical Communication

    NASA Technical Reports Server (NTRS)

    Wang, Xinghua; Wang, Bin; Bos, Philip J.; Anderson, James E.; Pouch, John; Miranda, Felix; McManamon, Paul F.

    2004-01-01

    The 2-D Optical Phased Array (OPA) antenna based on a Liquid Crystal On Silicon (LCoS) device can be considered for use in free space optical communication as an active beam controlling device. Several examples of the functionality of the device include: beam steering in the horizontal and elevation direction; high resolution wavefront compensation in a large telescope; and beam shaping with the computer generated kinoform. Various issues related to the diffraction efficiency, steering range, steering accuracy as well as the magnitude of wavefront compensation are discussed.

  8. Liquid Crystal-based Beam Steering Technologies for NASA Applications

    NASA Technical Reports Server (NTRS)

    Pouch, John; Nguyen, Hung; Miranda, Felix; Bos, Philip; Lavrentovich, Oleg; Wang, Xinghua; Pishnyak, Oleg; Kreminska, Liubov; Golovin, Andrii

    2006-01-01

    Liquid crystal-based beam steering devices can provide electronic beam scanning to angles above 1 milliradian, sub-microradian beam pointing accuracy, as well as wave-front correction to maintain output optical beam quality. The liquid crystal technology effort will be summarized, and the potential application of the resulting devices to NASA space-based scenarios will be described.

  9. 46 CFR 176.814 - Steering systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Steering systems. 176.814 Section 176.814 Shipping COAST...) INSPECTION AND CERTIFICATION Material Inspections § 176.814 Steering systems. At each initial and subsequent inspection for certification the owner or managing operator shall be prepared to test the steering systems...

  10. Laser beam steering for GRACE Follow-On intersatellite interferometry.

    PubMed

    Schütze, Daniel; Stede, Gunnar; Müller, Vitali; Gerberding, Oliver; Bandikova, Tamara; Sheard, Benjamin S; Heinzel, Gerhard; Danzmann, Karsten

    2014-10-01

    The GRACE Follow-On satellites will use, for the first time, a Laser Ranging Interferometer to measure intersatellite distance changes from which fluctuations in Earth's geoid can be inferred. We have investigated the beam steering method that is required to maintain the laser link between the satellites. Although developed for the specific needs of the GRACE Follow-On mission, the beam steering method could also be applied to other intersatellite laser ranging applications where major difficulties are common: large spacecraft separation and large spacecraft attitude jitter. The beam steering method simultaneously coaligns local oscillator beam and transmitted beam with the laser beam received from the distant spacecraft using Differential Wavefront Sensing. We demonstrate the operation of the beam steering method on breadboard level using GRACE satellite attitude jitter data to command a hexapod, a six-degree-of-freedom rotation and translation stage. We verify coalignment of local oscillator beam/ transmitted beam and received beam of better than 10 μrad with a stability of 10 μrad/ √Hz in the GRACE Follow-On measurement band of 0.002...0.1 Hz. Additionally, important characteristics of the beam steering setup such as Differential Wavefront Sensing signals, heterodyne efficiency, and suppression of rotation-to-pathlength coupling are investigated and compared with analysis results. PMID:25321987

  11. 49 CFR 393.209 - Steering wheel systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... or slipping. The system shall not leak. The power steering system shall have sufficient fluid in the... following parameters: Steering wheel diameter Manual steering system Power steering system 406 mm or less... rotation for manual steering systems, and 30 degrees angular rotation for power steering systems....

  12. Apparatus for controlling steering power in power steering system

    SciTech Connect

    Hirakushi, S.; Matsubara, H.

    1988-10-04

    This patent describes an apparatus for controlling a steering power in a power steering system which is used in an automobile. The apparatus consists of: a main pump which supplies a first hydraulic coil to the power steering system to operate the same; an oil pressure reaction chamber for controlling the steering power; a subpump of a reduced size smaller than that of the main pump for supplying a second hydraulic oil to the oil pressure reaction chamber to operate the same; a first oil path interconnecting the subpump and oil pressure reaction chamber to each other for flowing the second hydraulic oil through the first oil path; an oil tank; a second oil path branched from the first oil path and connected to the oil tank; a first control valve means disposed in the second oil path for raising the hydraulic pressure of the oil pressure reaction chamber in response to an increase in the running speed of the automobile so as to control the oil pressure reaction chamber to increase the steering power; and a second control valve means connected in parallel relationship with the first control valve means for changing the steering power in response to the hydraulic pressure of the first hydraulic oil supplied from the main pump.

  13. Practicality of electronic beam steering for MST/ST radars, part 6.2A

    NASA Technical Reports Server (NTRS)

    Clark, W. L.; Green, J. L.

    1984-01-01

    Electronic beam steering is described as complex and expensive. The Sunset implementation of electronic steering is described, and it is demonstrated that such systems are cost effective, versatile, and no more complex than fixed beam alternatives, provided three or more beams are needed. The problem of determining accurate meteorological wind components in the presence of spatial variation is considered. A cost comparison of steerable and fixed systems allowing solution of this problem is given. The concepts and relations involved in phase steering are given, followed by the description of the Sunset ST radar steering system. The implications are discussed, references to the competing SAD method are provided, and a recommendation concerning the design of the future Doppler ST/MST systems is made.

  14. Optical beam steering using a 2D MEMS scanner

    NASA Astrophysics Data System (ADS)

    Pétremand, Yves; Clerc, Pierre-André; Epitaux, Marc; Hauffe, Ralf; Noell, Wilfried; de Rooij, N. F.

    2007-10-01

    This paper presents the design, fabrication and operation principle of an optical beam steerer for laser fiber coupling based on a MEMS device. The MEMS chip consists on a bi-dimensional movable platform based on uni-dimensional comb drive actuation. An optical lens is assembled onto the mobile platform to focus and steer the light comping from a laser diode and couple it into an optical fiber. Assembly of a complete system and measurements were performed and compared to simulation results. Both the trajectory of the MEMS and resonance frewquency measurements agree with the simulated ones.

  15. Remote manipulator system steering capability for SVDS

    NASA Technical Reports Server (NTRS)

    Martin, D. T.

    1977-01-01

    Details of the remote manipulator system steering capability to be implemented into the space vehicle dynamics simulator are reported. The resolve rate law is included as part of the overall steering capability. The steering model includes three automatic modes, four manual augmented modes, and a single joint rate mode.

  16. Semiconductor Laser With Two-Dimensional Beam Steering

    NASA Technical Reports Server (NTRS)

    Katz, J.

    1986-01-01

    Modification of monolithic semiconductor injection laser capable of one-dimensional electronic beam steering enables deflection of beam in second direction. Such laser chip provides beam pointing or raster scanning for applications in optical communications, data processing, image scanning, and optical ranging.

  17. Electrowetting-Controlled Dual Liquid Prism for Adaptive Beam Steering

    NASA Astrophysics Data System (ADS)

    Cheng, Jiangtao

    2015-03-01

    The use of concentrating photovoltaic (CPV) technology has been the most promising method of harvesting solar radiation. These CPV systems often require motor-driven tracking devices to steer the sun's beams onto solar cells. The cost of maintaining these tracking systems is the primary inhibitor for widespread application. We aim to overcome the need for mechanical trackers through the use of an electrowetting-driven solar tracking (EWST) system. The electrowetting-driven solar tracking system consists of an array of novel electrowetting-controlled dual liquid prisms, which are filled with immiscible fluids that have large differences in refractive indices. The naturally formed meniscus between the fluids can function as a dynamic optical prism. Via the full-range modulation of the liquid prisms, incident sunlight can be adaptively tracked, steered, and focused onto CPV cells through a fixed optical condenser. Furthermore, unlike the conventional and cumbersome motor-driven tracking systems used today, the liquid prism system would be suitable for rooftop applications. The results of this project reveal that the EWST system has the potential to generate ~ 70% more green energy at 50% of the conventional capital cost.

  18. 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.

  19. 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

  20. Diffraction Efficiency of Thin Film Holographic Beam Steering Devices

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

    Dynamic holography has been demonstrated as a method for correcting aberrations in space deployable optics, and can also be used to achieve high-resolution beam steering in the same environment. In this paper, we consider some of the factors affecting the efficiency of these devices. Specifically, the effect on the efficiency of a highly collimated beam from the number of discrete phase steps per period is considered for a blazed thin film beam steering grating. The effect of the number of discrete phase steps per period on steering resolution is also considered. We also present some result of Finite-Difference Time-Domain (FDTD) calculations of light propagating through liquid crystal "blazed" gratings. Liquid crystal gratings are shown to spatially modulate both the phase and amplitude of the propagating light.

  1. Forming and steering of symmetrical multiple laser beams in optical phased array

    NASA Astrophysics Data System (ADS)

    Liu, Xiang; Zhang, Jian; Wu, Liying; Gan, Yu; Wang, Dong; Ge, Jiajia

    2010-04-01

    Multi-beam technology is one of the key technologies in optical phased array systems for multi-object treatment and multi-task operation. A multi-beam forming and steering method was proposed. This method uses isosceles triangle multilevel phase grating (ITMPG) to form multiple beams simultaneously. Phase profile of the grating is a quantized isosceles triangle with stairs. By changing the phase difference corresponding to the triangle height, multiple beams can be steered symmetrically. It took 34 ms to calculate a set of parameters for one ITMPG, namely one steering. A liquid crystal spatial light modulator was used for the experiment, which formed 6 gratings. The distortion of which had been compensated with the accuracy of 0.0408 λ. Each grating included 16 phase elements with the same period. Steering angle corresponded to the triangle height, which is the phase difference. Relative diffraction efficiency for multiple beams was greater than 81%, intensity nonuniformity was less than 0.134, and the deflection resolution was 2.263 mrad. Experimental results demonstrate that the proposed method can be used to form and steer symmetrical multiple beams simultaneously with the same intensity and high diffraction efficiency in the far field, the deflection resolution is related to the reciprocal of grating period.

  2. Free-space transmission with passive 2D beam steering for multi-gigabit-per-second per-beam indoor optical wireless networks.

    PubMed

    Oh, Chin Wan; Cao, Zizheng; Tangdiongga, Eduward; Koonen, Ton

    2016-08-22

    In order to circumvent radio spectrum congestion, we propose an innovative system which can provide multiple infrared optical wireless beams simultaneously where each beam supports multi-gigabit-per-second communication. Scalable two-dimensional beam steering by means of wavelength tuning is proposed. A passive beam-steering module constructed with cascaded reflection gratings is designed for simultaneous multi-user coverage. We experimentally characterized the beam-steered system and thoroughly evaluated the performance of steered channels using the spectrally efficient and robust discrete multitone modulation in a bandwidth-limited system deploying 10 GHz telecom transceivers. This study reports the achievement of at least 37 Gbps free-space transmission per beam over a distance of up to 2 m over 5.61° × 12.66° scanning angles. PMID:27557201

  3. Oblique incidence effect on steering efficiency of liquid crystal polarization gratings used for optical phased array beam steering amplification

    NASA Astrophysics Data System (ADS)

    Xiangjie, Zhao; Jiazhu, Duan; Dayong, Zhang; Cangli, Liu; Yongquan, Luo

    2016-07-01

    A liquid crystal polarization grating (LCPG) is proposed that amplifies the steering angle of a liquid crystal optical phased array for non-mechanical beam steering, taking advantage of its high steering efficiency under normal incidence. However, oblique incidence may play an important role in the overall steering efficiency. The effect of oblique incidence on steering efficiency of a LCPG was analyzed by numerically solving the extended Jones matrix and considering propagation crosstalk. The results indicate that the outgoing laser beam is amplitude-modulated under the effect of oblique incidence and behaves as a sinusoidal-modulated amplitude grating, which diffracts certain energies to non-blazed orders. Over-oblique incidence may even eliminate the steering effect of the incident beam. The modulation depth of the induced amplitude grating was found to be proportional to the product of sinusoidal value of oblique incidence angle and the LC layer thickness, and inversely proportional to the periodic pitch length of the LCPG. Both in-plane incidence and out-of-plane incidence behave similarly to influence the steering efficiency. Finally, the overall steering efficiency for cascaded LCPGs was analyzed and a difference of up to 11 % steering efficiency can be induced between different LCPG configurations, even without considering the over-oblique incidence effect. Both the modulation depth and final steering efficiency can be optimized by varying the LC birefringence and layer thickness.

  4. Adaptive beam tracking and steering via electrowetting-controlled liquid prism

    SciTech Connect

    Cheng, JT; Chen, CL

    2011-11-07

    We report an electrowetting-controlled optofluidic system for adaptive beam tracking and agile steering. With two immiscible fluids in a transparent cell, we can actively control the contact angle along the fluid-fluid-solid tri-junction line and hence the orientation of the fluid-fluid interface via electrowetting. The naturally formed meniscus between the two liquids can function as an optical prism. We have fabricated a liquid prism module with an aperture size of 10 mm -10mm. With 1 wt.% KCl and 1 wt.% Sodium Dodecyl Sulfate added into deionized water, the orientation of the water-silicone oil interface has been modulated between -26 degrees and 26 degrees that can deflect and steer beam within the incidence angle of 0 degrees-15 degrees. The wide-range beam tracking and steering enables the liquid prism work as an electrowetting solar cell. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3660578

  5. Adaptive beam tracking and steering via electrowetting-controlled liquid prism

    NASA Astrophysics Data System (ADS)

    Cheng, Jiangtao; Chen, Chung-Lung

    2011-11-01

    We report an electrowetting-controlled optofluidic system for adaptive beam tracking and agile steering. With two immiscible fluids in a transparent cell, we can actively control the contact angle along the fluid-fluid-solid tri-junction line and hence the orientation of the fluid-fluid interface via electrowetting. The naturally formed meniscus between the two liquids can function as an optical prism. We have fabricated a liquid prism module with an aperture size of 10 mm × 10mm. With 1 wt. % KCl and 1 wt. % Sodium Dodecyl Sulfate added into deionized water, the orientation of the water-silicone oil interface has been modulated between -26° and 26° that can deflect and steer beam within the incidence angle of 0°-15°. The wide-range beam tracking and steering enables the liquid prism work as an electrowetting solar cell.

  6. Suppression of beam steering in an injection-locked laser diode array

    SciTech Connect

    Brewer, L.R. )

    1991-12-09

    Experimental measurements were made to demonstrate that the degree of beam steering in an injection-locked laser diode array is related to the divergence of the master laser beam. For a collimated master laser beam the beam steering was suppressed. The injection-locked laser diode array beam steers with the master laser wavelength because only a portion of the divergent master laser beam satisfies the round trip mode condition.

  7. Hybrid silicon free-space source with integrated beam steering

    NASA Astrophysics Data System (ADS)

    Doylend, J. K.; Heck, M. J. R.; Bovington, J. T.; Peters, J. D.; Davenport, M. L.; Coldren, L. A.; Bowers, J. E.

    2013-02-01

    Free-space beam steering using optical phase arrays are desirable as a means of implementing Light Detection and Ranging (LIDAR) and free-space communication links without the need for moving parts, thus alleviating vulnerabilities due to vibrations and inertial forces. Implementing such an approach in silicon photonic integrated circuits is particularly desirable in order to take advantage of established CMOS processing techniques while reducing both device size and packaging complexity. In this work we demonstrate a free-space diode laser together with beam steering implemented on-chip in a silicon photonic circuit. A waveguide phased array, surface gratings, a hybrid III-V/silicon laser and an array of hybrid III/V silicon amplifiers were fabricated on-chip in order to achieve a fully integrated steerable free-space optical source with no external optical inputs, thus eliminating the need for fiber coupling altogether. The chip was fabricated using a modified version of the hybrid silicon process developed at UCSB, with modifications in order to incorporate diodes within the waveguide layer as well as within the III-V gain layer. Beam steering across a 12° field of view with +/-0.3° accuracy and 1.8°x0.6° beam width was achieved, with background peaks suppressed 7 dB relative to the main lobe within the field of view for arbitrarily chosen beam directions.

  8. Analysis of beam steering tolerances and divergence for various long range FSO communication links

    NASA Astrophysics Data System (ADS)

    Harris, Alan; Sluss, James J., Jr.; Refai, Hazem H.; LoPresti, Peter G.

    2005-06-01

    Through the use of recent technological developments, it is now feasible to establish free-space optical (FSO) communication links over ultra-long distances. Recent research has shown that FSO systems could be deployed to establish high-rate data links to deep space. This study analyzes beam steering tolerances, beam divergence, and geometric loss for different distance ranges of interest for FSO communication links based on a mechanical gimbaled beam steering mechanism. The tolerance, divergence and geometric loss calculations are performed to evaluate the feasibility of establishing FSO links between the Earth and satellites, the Earth and aircraft, aircraft and satellites, the Earth and moon, the Earth and Mars, and the Earth and the edge of the solar system. The analysis and calculations performed take into consideration the availability of new technology such as low noise photon-counting detectors and fiber lasers and amplifiers. The beam steering tolerance and divergence calculations provide beneficial information for determining the extent to which future FSO systems could be deployed for both commercial, military and space exploration applications. Recommendations on the suitability of an FSO communication link for various applications are then made based on the beam steering tolerance and divergence calculations.

  9. 46 CFR 169.623 - Power-driven steering systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Power-driven steering systems. 169.623 Section 169.623... Machinery and Electrical Steering Systems § 169.623 Power-driven steering systems. (a) Power-driven steering... system must automatically resume operation after an electric power outage. (b) Control of...

  10. 46 CFR 169.623 - Power-driven steering systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Power-driven steering systems. 169.623 Section 169.623... Machinery and Electrical Steering Systems § 169.623 Power-driven steering systems. (a) Power-driven steering... system must automatically resume operation after an electric power outage. (b) Control of...

  11. Liquid Crystal-Based Beam Steering Device Development for NASA Applications

    NASA Technical Reports Server (NTRS)

    Pouch, John; Nguyen, Hung; Miranda, Felix; Bos, Philip; Lavrentovich, Oleg; Wang, Xinghua

    2004-01-01

    The NASA Computing, Information and Communications Technology (CICT) Program is supporting the development of liquid crystal-based beam steering devices. The device would use inexpensive, light-weight, optical components, and it would have the following capabilities: electronic beam scanning to angles above 1 milliradian, and submicroradian beam pointing accuracy. In order to correct for the imperfections resulting from the space-deployable optics, the technique of wave-front correction would be implemented. Hence, the output beam quality would be maintained. The potential applications could include satellite tracking, near-Earth inter-satellite communications, deep-space communications, and optical phased array systems. The status of the beam steering device development based on the liquid crystal technology and its relationship to prospective NASA mission scenarios will be described.

  12. Coherent optical monolithic phased-array antenna steering system

    DOEpatents

    Hietala, Vincent M.; Kravitz, Stanley H.; Vawter, Gregory A.

    1994-01-01

    An optical-based RF beam steering system for phased-array antennas comprising a photonic integrated circuit (PIC). The system is based on optical heterodyning employed to produce microwave phase shifting by a monolithic PIC constructed entirely of passive components. Microwave power and control signal distribution to the antenna is accomplished by optical fiber, permitting physical separation of the PIC and its control functions from the antenna. The system reduces size, weight, complexity, and cost of phased-array antenna systems.

  13. Terahertz beam steering and frequency tuning by using the spatial dispersion of ultrafast laser pulses.

    PubMed

    Maki, Ken-ichiro; Otani, Chiko

    2008-07-01

    We demonstrate a terahertz (THz) beam steering method using difference frequency generation that is based on the principle of phased array antennas. A strip-line photoconductive antenna was illuminated by two spatially dispersed beams produced from an ultrafast laser. THz radiation with a bandwidth of 65 GHz was generated from the overlapping area of the two beams, between which the frequency difference was approximately constant. We confirmed that the THz beam can be steered by tilting one of the incident pump beams so as to change their relative phase relation. The steering range of the THz beam was 29 degrees when the angle between the incident pump beams was only varied within a range of 0.155 degrees, that is, 187 times less. In addition, by laterally shifting one of the pump beams, the frequency of the THz radiation could be tuned from 0.3 to 1.7 THz. This technique can be applied to high-speed terahertz imaging and spectroscopy systems. PMID:18607423

  14. New approaches to enhance active steering system functionalities: preliminary results

    NASA Astrophysics Data System (ADS)

    Serarslan, Benan

    2014-09-01

    An important development of the steering systems in general is active steering systems like active front steering and steer-by-wire systems. In this paper the current functional possibilities in application of active steering systems are explored. A new approach and additional functionalities are presented that can be implemented to the active steering systems without additional hardware such as new sensors and electronic control units. Commercial active steering systems are controlling the steering angle depending on the driving situation only. This paper introduce methods for enhancing active steering system functionalities depending not only on the driving situation but also vehicle parameters like vehicle mass, tyre and road condition. In this regard, adaptation of the steering ratio as a function of above mentioned vehicle parameters is presented with examples. With some selected vehicle parameter changes, the reduction of the undesired influences on vehicle dynamics of these parameter changes has been demonstrated theoretically with simulations and with real-time driving measurements.

  15. Field Emitter Magnetic Sensor with Steered Focused Electron Beam

    NASA Astrophysics Data System (ADS)

    Nicolaescu, Dan; Filip, Valeriu; Itoh, Junji

    2001-04-01

    A novel field emission magnetic sensor is proposed and its operation is theoretically analyzed. The sensor comprises a dual-gate wedge field emitter with a split gate having the double role of focusing and steering the electron beam. The electron beam deflection due to the Lorentz force is compensated by appropriate potentials applied to this electrode. The modeling results have been obtained using the Simion 3D 7.0 software package. The device has high sensitivity and its operation is not influenced by fluctuations in the emission current. Arrangements of mutually normal wedge emitters can be used for two-dimensional magnetic field sensing.

  16. Non-Mechanical Beam Steering in Free-Space Optical Communication Transceivers

    NASA Astrophysics Data System (ADS)

    Shortt, Kevin

    Free-space optical communications systems are a rapidly growing field as they carry many of the advantages of traditional fibre-based communications systems without the added investment of installing complex infrastructure. Moreover, these systems are finding key niches in mobile platforms in order to take advantage of the increased bandwidth over traditional RF systems. Of course, the inevitable problem of tracking arises when dealing with mobile stations. To compound the problem in the case of communications to low Earth or geosynchronous orbits, FSOC systems typically operate with tightly confined beams over great distances often requiring pointing accuracies on the order of micro-radians or smaller. Mechanisms such as gimbal mounts and fine-steering mirrors are the usual candidates for platform stabilization, however, these clearly have substantial power requirements and inflate the mass of the system. Spatial light modulators (also known as optical phased arrays), on the other hand, offer a suitable alternative for beam-pointing stabilization. Some of the advantages of spatial light modulators over fine-steering mirrors include programmable multiple simultaneous beams, dynamic focus/defocus and moderate to excellent optical power handling capability. This thesis serves as an investigation into the implementation of spatial light modulators as a replacement for traditional fine-steering mirrors in the fine-pointing subsystem. In particular, pointing accuracy and scanning ability will be highlighted as performance metrics in the context of a variety of communication scenarios. Keywords: Free-space optical communications, beam steering, fine-steering mirror, spatial light modulator, optical phased array.

  17. Conceptual design of a beam steering lens through transformation electromagnetics.

    PubMed

    Yi, Jianjia; Burokur, Shah Nawaz; de Lustrac, André

    2015-05-18

    In this paper, based on transformation electromagnetics, the design procedure of a lens antenna, which steers the radiated beam of a patch array, is presented. Laplace's equation is adopted to construct the mapping between the virtual space and the physical space. The two dimensional (2D) design method can be extended to a potential three-dimensional (3D) realization, and with a proper parameter simplification, the lens can be further realized by common metamaterials or isotropic graded refractive index (GRIN) materials. Full wave simulations are performed to validate the proposed concept. It is observed that by placing the lens on a feeding source, we are able to steer the radiation emitted by the latter source. PMID:26074547

  18. Packaging consideration of two-dimensional polymer-based photonic crystals for laser beam steering

    NASA Astrophysics Data System (ADS)

    Dou, Xinyuan; Chen, Xiaonan; Chen, Maggie Yihong; Wang, Alan Xiaolong; Jiang, Wei; Chen, Ray T.

    2009-02-01

    In this paper, we report the theoretical study of polymer-based photonic crystals for laser beam steering which is based on the superprism effect as well as the experiment fabrication of the two dimensional photonic crystals for the laser beam steering. Superprism effect, the principle for beam steering, was separately studied in details through EFC (Equifrequency Contour) analysis. Polymer based photonic crystals were fabricated through double exposure holographic interference method using SU8-2007. The experiment results were also reported.

  19. Design and development of an electrically-controlled beam steering mirror for microwave tomography

    SciTech Connect

    Tayebi, A.; Tang, J.; Paladhi, P. Roy; Udpa, L.; Udpa, S.

    2015-03-31

    Microwave tomography has gained significant attention due to its reliability and unhazardous nature in the fields of NDE and medical industry. A new microwave tomography system is presented in this paper, which significantly reduces the design and operational complexities of traditional microwave imaging systems. The major component of the proposed system is a reconfigurable reflectarray antenna which is used for beam steering in order to generate projections from multiple angles. The design, modeling and fabrication of the building block of the antenna, a tunable unit cell, are discussed in this paper. The unit cell is capable of dynamically altering the phase of the reflected field which results in beam steering ability of the reflectarray antenna. A tomographically reconstructed image of a dielectric sample using this new microwave tomography system is presented in this work.

  20. Studies of non-linear optical effects for agile beam steering

    NASA Astrophysics Data System (ADS)

    Vachss, F.; McMichael, I.; Yeh, P.

    1993-11-01

    The objective of this program is the demonstration of a new technique for massless beam steering of high energy laser radiation. Using the effect of nonlinear electrostriction in acousto-optic devices, we show large improvements in diffraction efficiency and resolution. These results are obtained through the development of a novel geometry for acousto-optic beam steering and of a prototype device designed to take advantage of this geometry. Theoretical and experimental results of this effort establish the validity of large aperture, high frequency nonlinear acousto-optic beam steering. The results are found to be applicable to steering of high power laser beams.

  1. Laser stability and beam steering in a nonregular polygonal cavity.

    PubMed

    Currie, Bryn E; Stedman, Geoffrey E; Dunn, Robert W

    2002-03-20

    Two laser stability criteria or lasing conditions for cavity geometry based on the standard ABCD matrix analysis and the Bilger and Stedman analysis [Appl. Opt. 26, 3710 (1987)] are reconciled. Beam steering from mirror misalignment is discussed similarly, generalizing the Bilger and Stedman analysis to nonregular polygons by extending the standard ABCD matrix analysis to 3 x 3 matrices, which facilitates the thorough design of large rectangular ring lasers and is applied to a number of existing or planned ring lasers with perimeters of 77-120 m. PMID:11921797

  2. Modeling and control of a two-axis fast steering mirror with piezoelectric stack actuators for laser beam tracking

    NASA Astrophysics Data System (ADS)

    Zhu, Wei; Bian, Leixiang; An, Yi; Chen, Gangli; Rui, Xiaoting

    2015-07-01

    This paper outlines an optical beam steering system built using a two-axis fast steering mirror (FSM) with piezoelectric stack actuators to maintain precise pointing control. A novel mathematical model of the FSM is put forward by using a transfer matrix method of a multibody system to describe the dynamics characteristics and a hysteresis model to represent the hysteresis. Based on the proposed model, a model-based hybrid control is applied to force the output angle of the FSM to track the laser beam accurately thereafter. The experimental results are in accordance with the theoretical analysis. The results highlight significantly improved accuracy in the beam tracking control of the FSM.

  3. Beam steering and deflecting device using step-based micro-blazed grating

    NASA Astrophysics Data System (ADS)

    Yang, Junbo; Su, Xianyu; Xu, Ping; Gu, Zheng

    2008-08-01

    The rapidly evolving demands of optical communications and optical switching systems have created a new market for high capacity all-optical beam steering and deflecting techniques. One technology potentially capable of realizing such systems uses the multistep micro-blazed grating optical beam deflectors based on binary and multiple-phase modulation methods. The micro-optical element has been fabricated by introducing very large scale integration (VLSI), stepping photolithography and reactive ion etching (RIE), which can realize beam steering, deflecting, splitting, and switching in free space, and its diffraction properties are determined by the blazed-grating parameters, such as the number of steps, grating depth, grating period, as well as blazed profile. The theoretical analysis and primarily experimental result show that this phase-type element has the advantages of high diffractive efficiency, low cross talk, small feature size, and high reliability due to nonmechanical beam steering without any moving parts. Hence it is ideally suited to applications in optical communication and optical interconnection network.

  4. Bottom profiling by correlating beam-steered noise sequences.

    PubMed

    Harrison, Chris H; Siderius, Martin

    2008-03-01

    It has already been established that by cross-correlating ambient noise time series received on the upward and downward steered beams of a drifting vertical array one can obtain a subbottom layer profile. Strictly, the time differential of the cross correlation is the impulse response of the seabed. Here it is shown theoretically and by simulation that completely uncorrelated surface noise results in a layer profile with predictable amplitudes proportional to those of an equivalent echo sounder at the same depth as the array. The phenomenon is simulated by representing the sound sources as multiple random time sequences emitted from random locations in a horizontal plane above a vertical array and then accounting for the travel times of the direct and bottom reflected paths. A well-defined correlation spike is seen at the depth corresponding to the bottom reflection despite the fact that the sound sources contain no structure whatsoever. The effects of using simultaneously steered upward and downward conical beams with a tilted or faceted seabed and multiple layers are also investigated by simulation. Experimental profiles are obtained using two different vertical arrays in smooth and rough bottom sites in the Mediterranean. Correlation peak amplitudes follow the theory and simulations closely. PMID:18345817

  5. 46 CFR 169.623 - Power-driven steering systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Power-driven steering systems. 169.623 Section 169.623 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Steering Systems § 169.623 Power-driven steering systems. (a) Power-driven...

  6. 46 CFR 169.623 - Power-driven steering systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Power-driven steering systems. 169.623 Section 169.623 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Steering Systems § 169.623 Power-driven steering systems. (a) Power-driven...

  7. 46 CFR 169.623 - Power-driven steering systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Power-driven steering systems. 169.623 Section 169.623 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Steering Systems § 169.623 Power-driven steering systems. (a) Power-driven...

  8. Vertical flight path steering system for aircraft

    NASA Technical Reports Server (NTRS)

    Lambregts, Antonius A. (Inventor)

    1983-01-01

    Disclosed is a vertical flight path angle steering system for aircraft, utilizing a digital flight control computer which processes pilot control inputs and aircraft response parameters into suitable elevator commands and control information for display to the pilot on a cathode ray tube. The system yields desirable airplane control handling qualities and responses as well as improvements in pilot workload and safety during airplane operation in the terminal area and under windshear conditions.

  9. Steering system for a train of rail-less vehicles

    DOEpatents

    Voight, Edward T.

    1983-01-01

    A steering system for use with a multiple vehicle train permits tracking without rails of one vehicle after another. This system is particularly useful for moving conveyor systems into and out of curved paths of room and pillar underground mine installations. The steering system features an elongated steering bar pivotally connected to each of adjacent vehicles at end portions of the bar permitting angular orientation of each vehicle in respect to the steering bar and other vehicles. Each end portion of the steering bar is linked to the near pair of vehicle wheels through wheel yoke pivot arms about king pin type pivots. Movement of the steering bar about its pivotal connection provides proportional turning of the wheels to effect steering and tracking of one vehicle following another in both forward and reverse directions.

  10. Giant and high-resolution beam steering using slow-light waveguide amplifier.

    PubMed

    Gu, Xiaodong; Shimada, Toshikazu; Koyama, Fumio

    2011-11-01

    We propose a novel beam-steering device based on a slow-light waveguide amplifier. In this paper, we present the idea of this steering technique and show its modeling characteristics. Giant steering of the radiation beam is obtained by tuning the wavelength of input light, which is coupled into the Bragg reflector waveguide. A tunable deflection-angle range can be over 40 degrees. High beam coherency and flat intensity distribution enable us to obtain an ultra-large number of resolution-points over 1,000 for few-millimeter long devices. PMID:22109148

  11. Modeling and simulations of new electrostatically driven, bimorph actuator for high beam steering micromirror deflection angles

    NASA Astrophysics Data System (ADS)

    Walton, John P.; Coutu, Ronald A.; Starman, LaVern

    2015-02-01

    There are numerous applications for micromirror arrays seen in our everyday lives. From flat screen televisions and computer monitors, found in nearly every home and office, to advanced military weapon systems and space vehicles, each application bringing with it a unique set of requirements. The microelectromechanical systems (MEMS) industry has researched many ways micromirror actuation can be accomplished and the different constraints on performance each design brings with it. This paper investigates a new "zipper" approach to electrostatically driven micromirrors with the intent of improving duel plane beam steering by coupling large deflection angles, over 30°, and a fast switching speed. To accomplish this, an extreme initial deflection is needed which can be reached using high stress bimorph beams. Currently this requires long beams and high voltage for the electrostatic pull in or slower electrothermal switching. The idea for this "zipper" approach is to stack multiple beams of a much shorter length and allow for the deflection of each beam to be added together in order to reach the required initial deflection height. This design requires much less pull-in voltage because the pull-in of one short beam will in turn reduce the height of the all subsequent beams, making it much easier to actuate. Using modeling and simulation software to characterize operations characteristics, different bimorph cantilever beam configurations are explored in order to optimize the design. These simulations show that this new "zipper" approach increases initial deflection as additional beams are added to the assembly without increasing the actuation voltage.

  12. High power transcranial beam steering for ultrasonic brain therapy

    NASA Astrophysics Data System (ADS)

    Pernot, M.; Aubry, J.-F.; Tanter, M.; Thomas, J.-L.; Fink, M.

    2003-08-01

    A sparse phased array is specially designed for non-invasive ultrasound transskull brain therapy. The array is made of 200 single elements corresponding to a new generation of high power transducers developed in collaboration with Imasonic (Besançon, France). Each element has a surface of 0.5 cm2 and works at 0.9 MHz central frequency with a maximum 20 W cm-2 intensity on the transducer surface. In order to optimize the steering capabilities of the array, several transducer distributions on a spherical surface are simulated: hexagonal, annular and quasi-random distributions. Using a quasi-random distribution significantly reduces the grating lobes. Furthermore, the simulations show the capability of the quasi-random array to electronically move the focal spot in the vicinity of the geometrical focus (up to +/-15 mm). Based on the simulation study, the array is constructed and tested. The skull aberrations are corrected by using a time reversal mirror with amplitude correction achieved thanks to an implantable hydrophone, and a sharp focus is obtained through a human skull. Several lesions are induced in fresh liver and brain samples through human skulls, demonstrating the accuracy and the steering capabilities of the system.

  13. High power transcranial beam steering for ultrasonic brain therapy

    PubMed Central

    Pernot, Mathieu; Aubry, Jean-François; Tanter, Mickaël; Thomas, Jean-Louis; Fink, Mathias

    2003-01-01

    A sparse phased array is specially designed for non-invasive ultrasound transskull brain therapy. The array is made of 200 single-elements corresponding to a new generation of high power transducers developed in collaboration with Imasonic (Besançon, France). Each element has a surface of 0.5cm2 and works at 0.9 MHz central frequency with a maximum 20W.cm−2 intensity on the transducer surface. In order to optimize the steering capabilities of the array, several transducers distributions on a spherical surface are simulated: hexagonal, annular, and quasi-random distributions. Using a quasi-random distribution significantly reduces the grating lobes. Furthermore, the simulations show the capability of the quasi-random array to electronically move the focal spot in the vicinity of the geometrical focus (up to +/− 15 mm). Based on the simulation study, the array is constructed and tested. The skull aberrations are corrected by using a time reversal mirror with amplitude correction achieved thanks to an implantable hydrophone, and a sharp focus is obtained through a human skull. Several lesions are induced in fresh liver and brain samples through human skulls, demonstrating the accuracy and the steering capabilities of the system. PMID:12974575

  14. 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. PMID:22714214

  15. Optical beam steering using surface micromachined gratings and optical phased arrays

    NASA Astrophysics Data System (ADS)

    Burns, David M.; Bright, Victor M.; Gustafson, Steven C.; Watson, Edward A.

    1997-07-01

    Two categories of optical beam steering micro-electro- mechanical systems (MEMS) were investigated: variable blaze gratings (VBGs) and linear optical phased arrays. All devices were surface micromachined using the multi-user MEMS processes (MUMPs). VBGs use an adjustable blaze angle to direct the majority of reflected light into a selectable diffraction order. Diffraction efficiencies greater than 50% were demonstrated. Linear optical phased arrays use a single row of piston micromirrors to create a far-field pattern with a steerable main lobe along one axis. All devices were constructed of polysilicon and gold and were actuated with electrostatic force. Electrostatic actuation provides high speed operation at a very low drive power. These optical beam steering devices discussed in this work are less optically efficient than a single pivoting mirror, but they require no post-fabrication assembly and can handle large beam diameters. Also, the low individual mass of the elements in surface micromachined VBGs and optical phased arrays yield faster system response times than a single macroscale pivoting mirror.

  16. Report for simultaneous, multiple independently steered beam study for Airborne Electronically Steerable Phased Array (AESPA) program

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Design concepts of an array for the formation of multiple, simultaneous, independently pointed beams for satellite communication links were investigated through tradeoffs of various approaches which were conceived as possible solutions to the problem. After the preferred approach was selected, a more detailed design was configured and is presented as a candidate system that should be given further consideration for development leading to a preliminary design. This array uses an attenuator and a phase shifter with every element. The aperture excitation necessary to form the four beams is calculated and then placed across the array using these devices. Pattern analysis was performed for two beam and four beam cases with numerous patterns being presented. Parameter evaluation shown includes pointing accuracy and beam shape, sidelobe characteristics, gain control, and beam normalization. It was demonstrated that a 4 bit phase shifter and a 6 bit, 30 dB attenuator were sufficient to achieve adequate pattern performances. The phase amplitude steered multibeam array offers the flexibility of 1 to 4 beams with an increase in gain of 6 dB if only one beam is selected.

  17. Beam Steering Experiment with Two Cascaded Ferroelectric Liquid-Crystal Spatial Light Modulators

    NASA Astrophysics Data System (ADS)

    Engström, David; Hård, Sverker; Rudquist, Per; D'Havé, Koen; Matuszczyk, Tomasz; Skeren, Marek; Löfving, Björn

    2004-03-01

    The design, construction, and evaluation of a laser beam steerer that uses two binary ferroelectric liquid-crystal (FLC) spatial light modulators (SLMs) operated in conjunction are presented. The system is characterized by having few components and is in principle lossless. Experimentally, a throughput of ~20% was achieved. The simple system design was achieved because of the high tilt angle FLC material used in the SLMs, which were specifically designed and manufactured for this study. By coherently imaging the first SLM onto the second SLM, pixel by pixel, we obtained an effective four-level phase structure with a phase step of 90°. An appropriate alignment procedure is presented. The beam steering performance of the system is reported and analyzed.

  18. Certifying single-system steering for quantum-information processing

    NASA Astrophysics Data System (ADS)

    Li, Che-Ming; Chen, Yueh-Nan; Lambert, Neill; Chiu, Ching-Yi; Nori, Franco

    2015-12-01

    Einstein-Podolsky-Rosen (EPR) steering describes how different ensembles of quantum states can be remotely prepared by measuring one particle of an entangled pair. Here, we investigate quantum steering for single quantum d -dimensional systems (qudits) and devise efficient conditions to certify the steerability therein, which we find are applicable both to single-system steering and EPR steering. In the single-system case our steering conditions enable the unambiguous ruling out of generic classical means of mimicking steering. Ruling out "false-steering" scenarios has implications for securing channels against both cloning-based individual attack and coherent attacks when implementing quantum key distribution using qudits. We also show that these steering conditions also have applications in quantum computation, in that they can serve as an efficient criterion for the evaluation of quantum logic gates of arbitrary size. Finally, we describe how the nonlocal EPR variant of these conditions also function as tools for identifying faithful one-way quantum computation, secure entanglement-based quantum communication, and genuine multipartite EPR steering.

  19. Broadband time reversed acoustic focusing and steering system

    NASA Astrophysics Data System (ADS)

    Sutin, Alexander; Sarvazyan, Armen; Montaldo, Gabriel; Palacio, Delphine; Bercoff, Jeremy; Tanter, Mickael; Fink, Mathias

    2001-05-01

    We present results of experimental testing and theoretical modeling of a time reversal acoustic (TRA) focusing system based on a multifaceted aluminum resonator with 15 piezoceramic transducers glued to the resonator facets. One of the facets of the resonator, a pentagon with characteristic dimension of about 30 mm, was submerged into a water tank and served as a virtual phased array which provided ultrasound focusing and beam steering in a wide frequency band (0.7-3 MHz). Ultrasonic pulses with different carrier frequencies and various complex waveforms were focused; the focal length was varied in the range of 10-55 mm and the focused beam was steered in a range of angles of +/-60 deg. The amplitude of the signal in the focal region reached 40 MPa. A theoretical model was based on an assumption that the radiating part of the resonator works as a phase conjugation screen for a spherical wave radiated from the focal point. Theoretical dependencies of the field structure on the position of the focus point and ultrasound frequency are in a good agreement with experimental results. TRA based focusing of ultrasound has numerous applications in medical diagnostics, surgery and therapy. [Work supported by NIH grant.

  20. Steering and Suspension Systems. Auto Mechanics Curriculum Guide. Module 5. Instructor's Guide.

    ERIC Educational Resources Information Center

    Rains, Larry

    This module is the fifth of nine modules in the competency-based Missouri Auto Mechanics Curriculum Guide. Seventeen units cover: steering system design; diagnosing steering systems problems; inspecting and replacing steering linkage components; manual and power steering gear service; manual and power rack and pinion steering gear service; power…

  1. 49 CFR 570.60 - Steering system.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... steering axle wheels in the straight ahead position, turn the steering wheel in one direction until there... are correctly adjusted. Grasp the front and rear of a tire and attempt to turn the tire and wheel assemble left and right. If the free movement at the front or rear tread of the tire exceeds the...

  2. Demonstration of large-angle nonmechanical laser beam steering based on LC polymer polarization gratings

    NASA Astrophysics Data System (ADS)

    Kim, Jihwan; Miskiewicz, Matthew N.; Serati, Steve; Escuti, Michael J.

    2011-05-01

    Polarization gratings (PGs) as polarization sensitive diffractive optical elements work in broadband (UV to Mid- IR) with nearly 100% diffraction efficiency. We have introduced and utilized the PGs in different types of beam steering modules presented in our previous papers. Here, we describe and demonstrate a nonmechanical beam steering device based on passive gratings, liquid crystal (LC) polymer PGs. The device covers a large-angle Field-Of-Regard (FOR) with high efficiency, and is based on a stack of alternating LC half-wave plates and LC polymer PGs. The half-wave plates are switchable and are used to select the handedness of the circularly polarized input beam. The polymer PGs diffract the input beam to either of the first diffraction orders based on the circular handedness of the beam previously selected. When compared with conventional beam steering methods based on active gratings (ternary and quasi-ternary designs), this technique is experimentally able to steer an equivalent number of angles with similar efficiency, but fewer LC cells, and hence, fewer transparent electrodes and lower absorption. We successfully demonstrate the ability to steer 80° FOR with roughly 2.6° resolution at 1064 nm wavelength.

  3. Theoretical and experimental determination of steering mechanism for Risley prism systems.

    PubMed

    Lu, Yafei; Zhou, Yuan; Hei, Mo; Fan, Dapeng

    2013-03-01

    Two different analytical methods, the first-order paraxial approximation method and the nonparaxial ray tracing method, are applied to determine the steering mechanism of the Risley prism system, including the pointing prediction and the complete and exact inverse orientation solutions. The analytical results obtained with the two different methods are investigated in detail about the pointing prediction and the two groups of inverse orientation solutions, respectively. Risley prism equipment for wide angular range beam scanning is assembled and the experimental setup is built to test the steering mechanism of the Risley prism system. Experimental results validate the availability of the nonparaxial ray tracing method to discuss the beam steering mechanism for the Risley prism system. PMID:23458790

  4. 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.

  5. 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.

  6. Low Cost Beam-Steering Approach for a Series-Fed Array

    NASA Technical Reports Server (NTRS)

    Host, Nicholas K.; Chen, Chi-Chih; Volakis, John L.; Miranda, Felix A.

    2013-01-01

    Phased array antennas showcase many advantages over mechanically steered systems. However, they are also more complex and costly. This paper presents a concept which overcomes these detrimental attributes by eliminating all of the phased array backend (including phase shifters). Instead, a propagation constant reconfigurable transmission line in a series fed array arrangement is used to allow phase shifting with one small (less than or equal to 100mil) linear mechanical motion. A novel slotted coplanar stripline design improves on previous transmission lines by demonstrating a greater control of propagation constant, thus allowing practical prototypes to be built. Also, beam steering pattern control is explored. We show that with correct choice of line impedance, pattern control is possible for all scan angles. A 20 element array scanning from -25 deg less than or equal to theta less than or equal to 21 deg. with mostly uniform gain at 13GHz is presented. Measured patterns show a reduced scan range of 12 deg. less than or equal to theta less than or equal to 25 deg. due to a correctable manufacturing error as verified by simulation. Beam squint is measured to be plus or minus 2.5 deg for a 600MHz bandwidth and cross-pol is measured to be at least -15dB.

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

    NASA Astrophysics Data System (ADS)

    Shi, Yubin; Zhang, Jianmin; Zhang, Zhen

    2016-06-01

    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.

  8. MSAT-X electronically steered phased array antenna system

    NASA Technical Reports Server (NTRS)

    Chung, H. H.; Foy, W.; Schaffner, G.; Pagels, W.; Vayner, M.; Nelson, J.; Peng, S. Y.

    1988-01-01

    A low profile electronically steered phased array was successfully developed for the Mobile Satellite Experiment Program (MSAT-X). The newly invented cavity-backed printed crossed-slot was used as the radiating element. The choice of this element was based on its low elevation angle gain coverage and low profile. A nineteen-way radial type unequal power divider and eighteen three-bit diode phase shifters constitute the beamformer module which is used to scan the beams electronically. A complete hybrid mode pointing system was also developed. The major features of the antenna system are broad coverage, low profile, and fast acquisition and tracking performance, even under fading conditions. Excellent intersatellite isolation (better than 26 dB) was realized, which will provide good quality mobile satellite communication in the future.

  9. Active terahertz beam steering by photo-generated graded index gratings in thin semiconductor films.

    PubMed

    Steinbusch, T P; Tyagi, H K; Schaafsma, M C; Georgiou, G; Gómez Rivas, J

    2014-11-01

    We demonstrate active beam steering of terahertz radiation using a photo-excited thin layer of gallium arsenide. A constant gradient of phase discontinuity along the interface is introduced by an spatially inhomogeneous density of free charge carriers that are photo-generated in the GaAs with an optical pump. The optical pump has been spatially modulated to form the shape of a planar blazed grating. The phase gradient leads to an asymmetry between the +1 and -1 transmission diffracted orders of more than a factor two. Optimization of the grating structure can lead to an asymmetry of more than one order of magnitude. Similar to metasurfaces made of plasmonic antennas, the photo-generated grating is a planar structure that can achieve large beam steering efficiency. Moreover, the photo-generation of such structures provides a platform for active THz beam steering. PMID:25401807

  10. A prototype of a beam steering assistant tool for accelerator operations

    SciTech Connect

    M. Bickley; P. Chevtsov

    2006-10-24

    The CEBAF accelerator provides nuclear physics experiments at Jefferson Lab with high quality electron beams. Three experimental end stations can simultaneously receive the beams with different energies and intensities. For each operational mode, the accelerator setup procedures are complicated and require very careful checking of beam spot sizes and positions on multiple beam viewers. To simplify these procedures and make them reproducible, a beam steering assistant GUI tool has been created. The tool is implemented as a multi-window control screen. The screen has an interactive graphical object window, which is an overlay on top of a digitized live video image from a beam viewer. It allows a user to easily create and edit any graphical objects consisting of text, ellipses, and lines, right above the live beam viewer image and then save them in a file that is called a beam steering template. The template can show, for example, the area within which the beam must always be on the viewer. Later, this template can be loaded in the interactive graphical object window to help accelerator operators steer the beam to the specified area on the viewer.

  11. Primary Beam Steering Due To Field Leakage From Superconducting SHMS Magnets

    NASA Astrophysics Data System (ADS)

    Moore, Michael; Covrig, Silviu; Carlini, Roger; Waidyawansa, Buddhini; Benesch, Jay

    2014-03-01

    The Super High Momentum Spectrometer (SHMS) was designed for the 12 GeV/c physics program in Hall C at Thomas Jefferson National Accelerator (JLab). At JLab an electron beam impinges on a fixed target and scattered particles are analyzed with magnetic spectrometers. The SHMS angular acceptance is 5 .5° <= θ <=40° . When positioned at θ = 5 .5° and full field strength the external fields from the magnets are large enough to steer the unscattered primary beam away from the beam dump window located 51.8 m from the target. The effects of these magnetic fields on the primary beam line downstream of the target are studied using Opera 3-D and TOSCA. A solution is presented that uses passive elements to shape these fields and assure that the primary beam is steered onto the beam dump window.

  12. Rear wheel suspension and steering system

    SciTech Connect

    Ewen, J.G.

    1990-07-17

    This patent describes an improvement in a rear wheel support and driving system. The system comprises a rack-type dead axle adapted to support a vehicle body thereupon through suitable spring means, a pair of wheels rotatably supported upon the dead axle, a differential drive mechanism adapted to be supported upon the vehicle body movable with the body relative to the dead axle, the differential mechanism including a power input shaft and power output shafts, a pair of live axles drivingly connecting the output shafts with the wheels. The dead axle being generally rectilinear in shape and having a first pair of longitudinal beams respectively transversely spaced outboard of the differential mechanism, a second pair of cross beams respectively spaced fore and aft of the differential mechanism and secured to the first pair of beams.

  13. Acoustic prism for continuous beam steering based on piezo-electric metamaterial

    NASA Astrophysics Data System (ADS)

    Xu, J.; Tang, J.

    2016-04-01

    This paper investigates an acoustic prism for continuous acoustic beam steering by a simple frequency sweep. This idea takes advantages of acoustic wave velocity shifting in metamaterials in the vicinity of local resonance. We apply this concept into the piezoelectric metamaterial consisting of host medium and piezoelectric LC shunt. Theoretical modeling and FEM simulations are carried out. It is shown that the phase velocity of acoustic wave changes dramatically in the vicinity of local resonance. The directions of acoustic wave can be adjusted continuously between 2 to 16 degrees by a simple sweep of the excitation frequency. Such an electro-mechanical coupling system has a feature of adjusting local resonance without altering the mechanical part of the system.

  14. Cyclic additional optical true time delay for microwave beam steering with spectral filtering.

    PubMed

    Cao, Z; Lu, R; Wang, Q; Tessema, N; Jiao, Y; van den Boom, H P A; Tangdiongga, E; Koonen, A M J

    2014-06-15

    Optical true time delay (OTTD) is an attractive way to realize microwave beam steering (MBS) due to its inherent features of broadband, low-loss, and compactness. In this Letter, we propose a novel OTTD approach named cyclic additional optical true time delay (CAO-TTD). It applies additional integer delays of the microwave carrier frequency to achieve spectral filtering but without disturbing the spatial filtering (beam steering). Based on such concept, a broadband MBS scheme for high-capacity wireless communication is proposed, which allows the tuning of both spectral filtering and spatial filtering. The experimental results match well with the theoretical analysis. PMID:24978496

  15. Optical phased array using high-contrast grating all-pass filters for fast beam steering

    NASA Astrophysics Data System (ADS)

    Yang, Weijian; Sun, Tianbo; Rao, Yi; Chan, Trevor; Megens, Mischa; Yoo, Byung-Wook; Horsley, David A.; Wu, Ming C.; Chang-Hasnain, Connie J.

    2013-03-01

    A novel 8x8 optical phased array based on high-contrast grating (HCG) all-pass filters (APFs) is experimentally demonstrated with high speed beam steering. Highly efficient phase tuning is achieved by micro-electro-mechanical actuation of the HCG to tune the cavity length of the APFs. Using APF phase-shifters allows a large phase shift with an actuation range of only tens of nanometers. The ultrathin HCG further ensures a high tuning speed (0.626 MHz). Both one-dimensional and two-dimensional HCGs are demonstrated as the actuation mirrors of the APF arrays with high beam steering performance.

  16. Beam Control and Steering in the University of Maryland Electron Ring (UMER)

    NASA Astrophysics Data System (ADS)

    Walter, M.; Bai, G.; Bernal, S.; Feldman, D.; Godlove, T.; Haber, I.; Holloway, M.; Kishek, R.; O'Shea, P.; Papadopoulos, C.; Quinn, B.; Reiser, M.; Stratakis, D.; Sutter, D.; Thangaraj, J.; Wilson, M.; Wu, C.

    2006-11-01

    The University of Maryland Electron Ring (UMER) is a low energy, high current recirculator for beam physics research. Ring construction has been completed for multi-turn operation of beams over a broad range of intensities and initial conditions. The electron beam current is adjustable up to 100 mA and pulse length as long as 100 ns. UMER is addressing issues in beam physics relevant to many applications that require intense beams of high quality, such as advanced concept accelerators, free electron lasers, spallalion neutron sources, and future heavy-ion drivers for inertial fusion. The primary focus of this presentation is experimental results in the area of beam steering and control within the injection line and ring. Unique beam steering algorithms now include measurement of the beam response matrix at each quadrupole and matrix inversion by singular value decomposition (SVD). With these advanced steering methods, transport of an intense beam over 50 turns (3600 full lattice periods) of the ring has been achieved.

  17. A Novel Approach to Beam Steering Using Arrays Composed of Multiple Unique Radiating Modes

    NASA Astrophysics Data System (ADS)

    Labadie, Nathan Richard

    Phased array antennas have found wide application in both radar and wireless communications systems particularly as implementation costs continue to decrease. The primary advantages of electronically scanned arrays are speed of beam scan and versatility of beamforming compared to mechanically scanned fixed beam antennas. These benefits come at the cost of a few well known design issues including element pattern rolloff and mutual coupling between elements. Our primary contribution to the field of research is the demonstration of significant improvement in phased array scan performance using multiple unique radiating modes. In short, orthogonal radiating modes have minimal coupling by definition and can also be generated with reduced rolloff at wide scan angles. In this dissertation, we present a combination of analysis, full-wave electromagnetic simulation and measured data to support our claims. The novel folded ring resonator (FRR) antenna is introduced as a wideband and multi-band element embedded in a grounded dielectric substrate. Multiple radiating modes of a small ground plane excited by a four element FRR array were also investigated. A novel hemispherical null steering antenna composed of two collocated radiating elements, each supporting a unique radiating mode, is presented in the context of an anti-jam GPS receiver application. Both the antenna aperture and active feed network were fabricated and measured showing excellent agreement with analytical and simulated data. The concept of using an antenna supporting multiple radiating modes for beam steering is also explored. A 16 element hybrid linear phased array was fabricated and measured demonstrating significantly improved scan range and scanned gain compared to a conventional phased array. This idea is expanded to 2 dimensional scanning arrays by analysis and simulation of a hybrid phased array composed of novel multiple mode monopole on patch antenna sub-arrays. Finally, we fabricated and

  18. Wide-angle nonmechanical beam steering using thin liquid crystal polarization gratings

    NASA Astrophysics Data System (ADS)

    Kim, Jihwan; Oh, Chulwoo; Escuti, Michael J.; Hosting, Lance; Serati, Steve

    2008-08-01

    We introduce and demonstrate a compact, nonmechanical beam steering device based on liquid Crystal (LC) Polarization Gratings (PGs). Directional control of collimated light is essential for free-space optical communications, remote sensing, and related technologies. However, current beam steering methods often require moving parts, or are limited to small angle operation, offer low optical throughput, and are constrained by size and weight. We employ multiple layers of LCPGs to achieve wide-angle (> +/-40°), coarse beam steering of 1550 nm light in a remarkably thin package. LCPGs can be made in switchable or polymer materials, and possess a continuous periodic birefringence profile, that renders several compelling properties (experimentally realized): ~ 100% experimental diffraction efficiency into a single order, high polarization sensitivity, and very low scattering. Light may be controlled within and between the zero- and first-diffraction orders by the handedness of the incident light and potentially by voltage applied to the PG itself. We implement a coarse steering device with several LCPGs matched with active halfwave LC variable retarders. Here, we present the preliminary experimental results and discuss the unique capability of this wide-angle steering.

  19. Towards doubling solar harvests using wide-angle, broad-band microfluidic beam steering arrays.

    PubMed

    DiDomenico, Leo D

    2015-11-30

    This paper introduces Microfluidic Beam Steering (MBS), which is a new technique for electronically steering light having multiple octaves of bandwidth, any polarization state and incidence from any direction of the sky without significant restrictions due to physical area, optical loss and power handling capacity. It is based on optical elements comprising both transparent solids and electronically controllable fluids to control Total Internal Reflection (TIR), refraction and/or diffraction from micro-structured surfaces within a transparent solid. A TIR-based MBS is discussed in the context of solar energy and its potential to significantly increase annual energy harvests from solar arrays situated on fixed areas like roofs. The advantages and challenges associated with analog and digital MBS systems are discussed and early-stage MBS hardware is demonstrated. Finally, an analytic model of sun-tracking is provided to formally establish the potential for MBS to increase annual solar energy harvests by approximately 45% more than conventional 0-Degree Of Freedom (0-DOF) solar arrays, 62% more than 1-DOF arrays and 233% more than 2-DOF arrays, all at 20% atmospheric aerosol scattering. PMID:26698790

  20. Primary beam steering due to field leakage from superconducting SHMS magnets

    SciTech Connect

    Moore, Michael H.; Waidyawansa, Buddhini P.; Covrig, Silviu; Carlini, Roger; Benesch, Jay

    2014-11-05

    In this study, simulations of the magnetic fields from the Super High Momentum Spectrometer in Hall C at Thomas Jefferson National Accelerator Facility show significant field leakage into the region of the primary beam line between the target and the beam dump. Without mitigation, these remnant fields will steer the unscattered beam enough to limit beam operations at small scattering angles. Presented here are magnetic field simulations of the spectrometer magnets and a solution using optimal placement of a minimal amount of shielding iron around the beam line.

  1. Primary beam steering due to field leakage from superconducting SHMS magnets

    NASA Astrophysics Data System (ADS)

    Moore, M. H.; Waidyawansa, B. P.; Covrig, S.; Carlini, R.; Benesch, J.

    2014-11-01

    Simulations of the magnetic fields from the Super High Momentum Spectrometer in Hall C at Thomas Jefferson National Accelerator Facility show significant field leakage into the region of the primary beam line between the target and the beam dump. Without mitigation, these remnant fields will steer the unscattered beam enough to limit beam operations at small scattering angles. Presented here are magnetic field simulations of the spectrometer magnets and a solution using optimal placement of a minimal amount of shielding iron around the beam line.

  2. Beam steering for virtual/augmented reality displays with a cycloidal diffractive waveplate.

    PubMed

    Chen, Haiwei; Weng, Yishi; Xu, Daming; Tabiryan, Nelson V; Wu, Shin-Tson

    2016-04-01

    We proposed a switchable beam steering device with cycloidal diffractive waveplate (CDW) for eye tracking in a virtual reality (VR) or augmented reality (AR) display system. Such a CDW diffracts the incident circularly polarized light to the first order with over 95% efficiency. To convert the input linearly polarized light to right-handed or left-handed circular polarization, we developed a broadband polarization switch consisting of a twisted nematic liquid crystal cell and an achromatic quarter-wave retardation film. By cascading 2-3 CDWs together, multiple diffraction angles can be achieved. To suppress the color dispersion, we proposed two approaches to obtain the same diffraction angle for red, green, and blue LEDs-based full color displays. Our device exhibits several advantages, such as high diffraction efficiency, fast response time, low power consumption, and low cost. It holds promise for the emerging VR/AR displays. PMID:27137019

  3. Demonstration of beam steering via dipole-coupled plasmonic spiral antenna.

    PubMed

    Rui, Guanghao; Abeysinghe, Don C; Nelson, Robert L; Zhan, Qiwen

    2013-01-01

    Optical antennas have been utilized to tailor the emission properties of nanoscale emitters in terms of the intensity, directivity and polarization. In this letter, we further explore the capability of beam steering via the use a spiral plasmonic structure as a transmitting antenna. According to both numerical simulation and experimental observations, the beaming direction can be steered through introducing a displacement of the feeding point to the spiral antenna from the geometrical center. For a 3-turn Archimedes' spiral antenna, experimental results show that steering angles of 3° and 7° are obtainable when the excitation location is transversally shifted from the center by a displacement of 200 nm and 500 nm, respectively. Furthermore, the emitted photons carry spin angular momentum determined by the chirality of the spiral optical antenna. A steerable nanoscale spin photon source may find important applications in single molecule sensing, quantum optical information processing and integrated photonic circuits. PMID:23868718

  4. Demonstration of beam steering via dipole-coupled plasmonic spiral antenna

    PubMed Central

    Rui, Guanghao; Abeysinghe, Don C.; Nelson, Robert L.; Zhan, Qiwen

    2013-01-01

    Optical antennas have been utilized to tailor the emission properties of nanoscale emitters in terms of the intensity, directivity and polarization. In this letter, we further explore the capability of beam steering via the use a spiral plasmonic structure as a transmitting antenna. According to both numerical simulation and experimental observations, the beaming direction can be steered through introducing a displacement of the feeding point to the spiral antenna from the geometrical center. For a 3-turn Archimedes' spiral antenna, experimental results show that steering angles of 3° and 7° are obtainable when the excitation location is transversally shifted from the center by a displacement of 200 nm and 500 nm, respectively. Furthermore, the emitted photons carry spin angular momentum determined by the chirality of the spiral optical antenna. A steerable nanoscale spin photon source may find important applications in single molecule sensing, quantum optical information processing and integrated photonic circuits. PMID:23868718

  5. 49 CFR 570.7 - Steering systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... binding or jamming in the steering gear mechanism. (d) Alignment. Toe-in and toe-out measurements shall... alignment setting. (1) Inspection procedure. Verify that toe-in or toe-out is not greater than 1.5 times the values listed in the vehicle manufacturer's service specification for alignment settings as measured by...

  6. 49 CFR 570.7 - Steering systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... binding or jamming in the steering gear mechanism. (d) Alignment. Toe-in and toe-out measurements shall... alignment setting. (1) Inspection procedure. Verify that toe-in or toe-out is not greater than 1.5 times the values listed in the vehicle manufacturer's service specification for alignment settings as measured by...

  7. 49 CFR 570.7 - Steering systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... binding or jamming in the steering gear mechanism. (d) Alignment. Toe-in and toe-out measurements shall... alignment setting. (1) Inspection procedure. Verify that toe-in or toe-out is not greater than 1.5 times the values listed in the vehicle manufacturer's service specification for alignment settings as measured by...

  8. 49 CFR 570.7 - Steering systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... binding or jamming in the steering gear mechanism. (d) Alignment. Toe-in and toe-out measurements shall... alignment setting. (1) Inspection procedure. Verify that toe-in or toe-out is not greater than 1.5 times the values listed in the vehicle manufacturer's service specification for alignment settings as measured by...

  9. 49 CFR 570.60 - Steering system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... is a perceptible movement of the wheel. If a point on the steering wheel rim moves more than the... Free Play Nominal bead diameter or rim size (inches) Play (inches) 16 or less 1/4 16.01 through 18.00...

  10. 49 CFR 570.60 - Steering system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... is a perceptible movement of the wheel. If a point on the steering wheel rim moves more than the... Free Play Nominal bead diameter or rim size (inches) Play (inches) 16 or less 1/4 16.01 through 18.00...

  11. 49 CFR 570.60 - Steering system.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... is a perceptible movement of the wheel. If a point on the steering wheel rim moves more than the... Free Play Nominal bead diameter or rim size (inches) Play (inches) 16 or less 1/4 16.01 through 18.00...

  12. 49 CFR 570.60 - Steering system.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... is a perceptible movement of the wheel. If a point on the steering wheel rim moves more than the... Free Play Nominal bead diameter or rim size (inches) Play (inches) 16 or less 1/4 16.01 through 18.00...

  13. Electrostatic steering and beamlet aiming in large neutral beam injectors

    SciTech Connect

    Veltri, P. Chitarin, G.; Marcuzzi, D.; Sartori, E.; Serianni, G.; Sonato, P.; Cavenago, M.

    2015-04-08

    Neutral beam injection is the main method for plasma heating in magnetic confinement fusion devices. In high energy injector (E>100 keV/amu), neutrals are obtained with reasonable efficiency by conversion of negative ions (H- or D-) via electron detachment reactions. In the case of ITER injectors, which shall operate at 1 MeV, a total ion current of ∼ 40 A is required to satisfy the heating power demand. Gridded electrodes are therefore used in the accelerator, so that 1280 negative ion beamlets are accelerated together. A carefully designed aiming system is required to control the beamlet trajectories, and to deliver their power on a focal point located several meters away from the beam source. In nowadays injectors, the aiming is typically obtained by aperture offset technique or by grid shaping. This paper discuss an alternative concept of beamlets aiming, based on an electrostatic ”steerer” to be placed at the end of the accelerator. A feasibility study of this component is also presented, and its main advantages and drawbacks with respect to other methods are discussed.

  14. Characterizing the beam steering and distortion of Gaussian and Bessel beams focused in tissues with microscopic heterogeneities

    PubMed Central

    Chen, Ye; Liu, Jonathan T.C.

    2015-01-01

    Bessel beams have recently been investigated as a means of improving deep-tissue microscopy in highly scattering and heterogeneous media. It has been suggested that the long depth-of-field and self-reconstructing property of a Bessel beam enables an increased penetration depth of the focused beam in tissues compared to a conventional Gaussian beam. However, a study is needed to better quantify the magnitude of the beam steering as well as the distortion of focused Gaussian and Bessel beams in tissues with microscopic heterogeneities. Here, we have developed an imaging method and quantitative metrics to evaluate the motion and distortion of low-numerical-aperture (NA) Gaussian and Bessel beams focused in water, heterogeneous phantoms, and fresh mouse esophagus tissues. Our results indicate that low-NA Bessel beams exhibit reduced beam-steering artifacts and distortions compared to Gaussian beams, and are therefore potentially useful for microscopy applications in which pointing accuracy and beam quality are critical, such as dual-axis confocal (DAC) microscopy. PMID:25909015

  15. Light steering of Air-Gaussian beam in Nonlocal Nonlinear Medium

    NASA Astrophysics Data System (ADS)

    Chen, Ran; Zhang, Xiaping

    2016-07-01

    With a nonlocal model, we investigate the propagation dynamics of a single Airy-Gaussian (AiG) beam and their interaction in one-dimensional condition by means of direct numerical simulations. With the split-step Fourier method, numerical results show that nonlocality can support periodic intensity distribution of AiG beams leading to the formation of stable bound states. Espesically, by tuning the phase difference between the two beams, we can steer the centre of the bound AiG beams in nonlocal nonlinear media.

  16. A compact beam focusing and steering element using quadrupoles with independently excited poles

    NASA Astrophysics Data System (ADS)

    Grime, Geoffrey W.

    2013-07-01

    Beam steering elements for accelerator beam transport are conventionally and conveniently incorporated into beamlines by fitting magnetic dipole elements around the vacuum tube of the line. Two steerers in each plane (X and Y) together with a quadrupole doublet constitute a module providing full control of the direction, position and focus of the beam. In some installations however, there may be insufficient space on the beamline to mount separate steerer elements. To provide steering capabilities in such a situation we have used a magnetic quadrupole doublet with the coils of each pole independently excited to synthesise the desired combination of quadrupole, horizontal dipole and vertical dipole fields. This paper describes the quadrupole steerer and its multichannel power supply and presents calculated magnetic field distributions together with raytracing simulation of its performance.

  17. A propulsion and steering control system for the Mars rover

    NASA Technical Reports Server (NTRS)

    Turner, J. M.

    1980-01-01

    The design of a propulsion and steering control system for the Rensselaer Polytechnic Institute prototype autonomous Mars roving vehicle is presented. The vehicle is propelled and steered by four independent electric motors. The control system must regulate the speeds of the motors so they work in unison during turns and on irregular terrain. An analysis of the motor coordination problem on irregular terrain, where each motor must supply a different torque at a different speed is presented. A procedure was developed to match the output of each motor to the varying load. A design for the control system is given. The controller uses a microprocessor which interprets speed and steering commands from an off-board computer, and produces the appropriate drive voltages for the motors.

  18. Initial investigation using statistical process control for quality control of accelerator beam steering

    PubMed Central

    2011-01-01

    Background This study seeks to increase clinical operational efficiency and accelerator beam consistency by retrospectively investigating the application of statistical process control (SPC) to linear accelerator beam steering parameters to determine the utility of such a methodology in detecting changes prior to equipment failure (interlocks actuated). Methods Steering coil currents (SCC) for the transverse and radial planes are set such that a reproducibly useful photon or electron beam is available. SCC are sampled and stored in the control console computer each day during the morning warm-up. The transverse and radial - positioning and angle SCC for photon beam energies were evaluated using average and range (Xbar-R) process control charts (PCC). The weekly average and range values (subgroup n = 5) for each steering coil were used to develop the PCC. SCC from September 2009 (annual calibration) until two weeks following a beam steering failure in June 2010 were evaluated. PCC limits were calculated using the first twenty subgroups. Appropriate action limits were developed using conventional SPC guidelines. Results PCC high-alarm action limit was set at 6 standard deviations from the mean. A value exceeding this limit would require beam scanning and evaluation by the physicist and engineer. Two low alarms were used to indicate negative trends. Alarms received following establishment of limits (week 20) are indicative of a non-random cause for deviation (Xbar chart) and/or an uncontrolled process (R chart). Transverse angle SCC for 6 MV and 15 MV indicated a high-alarm 90 and 108 days prior to equipment failure respectively. A downward trend in this parameter continued, with high-alarm, until failure. Transverse position and radial angle SCC for 6 and 15 MV indicated low-alarms starting as early as 124 and 116 days prior to failure, respectively. Conclusion Radiotherapy clinical efficiency and accelerator beam consistency may be improved by instituting SPC

  19. Optical properties of beam-steering elements utilizing volume holographic gratings

    NASA Astrophysics Data System (ADS)

    Butler, James Jay

    2000-06-01

    An optical beam steering element is a device that is used to control the direction in which a beam of light travels. We have investigated the optical properties of two classes of optical beam steering elements. The first type utilized the polarization dependence of the diffraction efficiency of volume holographic gratings. The second type utilized the fact that the diffraction efficiency of holograms imbibed with a nematic liquid crystal can be controlled by the application of an electric field. In both cases, elements with excellent switching contrasts were fabricated for operation in the visible and near infrared wavelength range including the commonly used telecommunications wavelength of 1.3μm. The holographic recording material that we have used is Polaroid Corporation's DMP-128 photopolymer. This material is porous after exposure and processing, a feature useful in two ways for this work. First, volume gratings with very large refractive index modulations, on the order of 0.2, can be fabricated using this material. Secondly, the pores can be filled with a nematic liquid crystal, resulting in electrically-switchable gratings. In our analysis of polarization-sensitive gratings we have employed several coupled wave theories, each with a different set of approximations. We have found that rigorous coupled wave theory must be used in predicting the diffractive properties of highly modulated volume gratings, where the effects of higher diffraction orders and form birefringence become important. In our analysis of the optical properties of electrically-switchable liquid crystal composite holograms, we have employed a theoretical analysis that treats the birefringent nature of the gratings. The results of Kogelnik theory that neglects the grating anisotropy, a two-wave theory that treats anisotropy, and a formulation of rigorous coupled wave theory that includes anisotropy were compared. We found it was necessary to include the effects of optical anisotropy to

  20. The Evolvement of Automobile Steering System Based on TRIZ

    NASA Astrophysics Data System (ADS)

    Zhao, Xinjun; Zhang, Shuang

    Products and techniques pass through a process of birth, growth, maturity, death and quit the stage like biological evolution process. The developments of products and techniques conform to some evolvement rules. If people know and hold these rules, they can design new kind of products and forecast the develop trends of the products. Thereby, enterprises can grasp the future technique directions of products, and make product and technique innovation. Below, based on TRIZ theory, the mechanism evolvement, the function evolvement and the appearance evolvement of automobile steering system had been analyzed and put forward some new ideas about future automobile steering system.

  1. Broadband polarization gratings for efficient liquid crystal display, beam steering, spectropolarimetry, and Fresnel zone plate

    NASA Astrophysics Data System (ADS)

    Oh, Chulwoo

    displays is the polymer-PG display, which allows an immediate brightness improvement (up to a factor of two) of conventional LC displays by replacing absorbing polarizers with achromatic PGs as thin, transmissive polymer films. We demonstrate the first proof-of-concept prototype projector based on the polymer-PG display and we also discuss optical design considerations and challenges toward a viable solution for our ultrabright pico-projector applications of the polymer-PG display. Second, two novel beam steering concepts based on the PG diffraction have been proposed. The polarization-sensitive diffraction of the PGs provides very attractive beam steering operations with ultra-high efficiency over wide steering angles by all-thin-plate electro-optical systems. We developed a non-mechanical, wide-angle beam steering system using stacked PGs and LC waveplates, and we also demonstrated a continuous beam steering using two rotating PGs, named the Risley grating as a thin-plate version of the Risley prism. The third PG application is in imaging and non-imaging spectropolarimetry. We have shown a snapshot, hyperspectral, full-Stokes polarimeter using inline PGs and quarter-waveplates. The use of PGs as a new polarimetric element for astronomical instruments in the mid-wave IR wavelengths also has been proposed to overcome current limitations of existing IR polarimeters. In the last part of this Dissertation, we introduce a polarization-type Fresnel zone plates (P-FZPs), comprising of spatially distributed linear birefringence or concentric PG (CPG) patterns. Effective fabrication methods of P-FZPs have been developed using polarization holography based on the Michelson interferometer and photoalignment of LC materials. We demonstrated high-quality P-FZPs, which exhibit ideal Fresnel-type lens effects, formed as both LC polymer films and electro-optical LC devices. We also discuss the polarization-selective lens properties of the P-FZPs as well as their electro-optical switching

  2. MIMO based optical phased array technology with electronic beam steering for laser radar applications

    NASA Astrophysics Data System (ADS)

    Sharma, Neha; Zmuda, Henry

    2010-04-01

    This paper will address the analysis and design of an electronically scanned phased array laser radar (ladar) system utilizing the techniques of multi-input multi-output (MIMO) array design. MIMO radar is has attracted much attention recently from both researchers and practitioners alike due to its significant potential for advancing the state-of-the-art RF radar technology. The laser radar architecture presented stands to gain significant inroads on the ability to apply RF array processing methods to laser radar systems in several ways. Specifically, using MIMO array design concepts, it is shown that the resolution of the ladar array can substantially exceed the diffraction limited resolution of a conventional array. Additionally, the use of array methods provides the capability to electronically steer the aperture, thus avoiding the mechanical beam scanning methods generally encountered in laser radar systems. Finally, by using an array of radiators, an increase in total radiated power is achieved, relieving the power burden on a single laser. The problems traditionally encountered in applying conventional array techniques to laser/detector arrays, for example, the inability to achieve half-wavelength spacing or the surfacing of source coherence issues, actually work to one's advantage when viewed in the MIMO paradigm. It is anticipated that the successful implementation of this system will significantly advance the state-of-the-art of laser radar capabilities for high speed imaging, target detection, tracking, and signature analysis.

  3. 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.

  4. Vertical split-ring resonator based anomalous beam steering with high extinction ratio

    PubMed Central

    Hsu, Wei-Lun; Wu, Pin Chieh; Chen, Jia-Wern; Chen, Ting-Yu; Cheng, Bo Han; Chen, Wei Ting; Huang, Yao-Wei; Liao, Chun Yen; Sun, Greg; Tsai, Din Ping

    2015-01-01

    Metasurfaces created artificially with metal nanostructures that are patterned on surfaces of different media have shown to possess “unusual” abilities to manipulate light. Limited by nanofabrication difficulties, so far most reported works have been based on 2D metal structures. We have recently developed an advanced e-beam process that allowed for the deposition of 3D nanostructures, namely vertical split-ring resonators (VSRRs), which opens up another degree of freedom in the metasurface design. Here we explore the functionality of beam steering with phase modulation by tuning only the vertical dimension of the VSRRs and show that anomalous steering reflection of a wide range of angles can be accomplished with high extinction ratio using the finite-difference-time-domain simulation. We also demonstrate that metasurfaces made of 3D VSRRs can be made with roughly half of the footprint compared to that of 2D nano-rods, enabling high density integration of metal nanostructures. PMID:26054048

  5. High power microwave beam steering based on gyromagnetic nonlinear transmission lines

    NASA Astrophysics Data System (ADS)

    Romanchenko, I. V.; Rostov, V. V.; Gunin, A. V.; Konev, V. Yu.

    2015-06-01

    We demonstrate electronically controlled beam steering by high power RF pulses produced by two gyromagnetic nonlinear transmission lines (NLTLs) connected to a one high voltage driver. Each NLTL is capable of producing several ns RF pulses with peak power from 50 to 700 MW (6% standard deviation) at frequencies from 0.5 to 1.7 GHz (1% standard deviation) with 100 Hz repetition rate. Using a helix antenna allows irradiating of RF pulses with almost circular polarization and 350 MW maximum peak power, which corresponds to 350 kV effective potential of radiation. At the installation of two identical channels, we demonstrate the possibility of beam steering within ±15° in the horizontal plane by coherent RF pulses with circular polarization at 1.0 GHz center frequency. Fourfold increase in the power flux density for in-phase irradiation of RF pulses is confirmed by comparison with one-channel operation.

  6. Effect of feeding system on performance and carcass characteristics of yearling steers, steer calves and heifer calves.

    PubMed

    Danner, M L; Fox, D G; Black, J R

    1980-03-01

    Three types of cattle (Angus x Hereford yearling steers, Charolais x British breed steer calves and Hereford heifer calves) were evaluated for their response to different feeding systems utilizing high moisture corn, corn silage and soybean meal as major feed ingredients. Feeding ing systems for steers included: A = 85% concentrate; B = 40% concentrate; C = two phase, with switch from all corn silage to 85% concentrate in the middle of the feeding period; D = same as C except switch occurred late in the feeding period; E = all corn silage continuously. Heifer diets consisted of the following ratios of corn silage to concentrate: low energy = 89:11; medium energy = 67:33; and high energy = 100 fed at a moderate (10.9% for low energy and medium energy, and 11.7% for high energy) and high (13.8%) crude protein level. Treatments within each experiment were terminated at approximately the same final weight. Increasing percentage corn added to the total diet increased ADG in most comparisons. Adjusted to a constant carcass weight, increasing dietary energy increased fat thickness and reduced percentage retail product with no effect on quality grade in yearling steers and heifer calves. In Charolais cross-steer calves, increasing energy level increased quality grade with no effect on yield grade or percentage retail product. Energetic efficiency slightly favored system C in yearling steers while steer calves maximized efficiency on A. Hereford heifers were the most energetically efficient on medium energy diets. PMID:7364676

  7. 2D Traveling Wave Array Employing a Trapezoidal Dielectric Wedge for Beam Steering

    NASA Technical Reports Server (NTRS)

    Host, Nicholas K.; Chen, Chi-Chih; Volakis, John L.; Miranada, Felix A.

    2014-01-01

    This presentation addresses the progress made so far in the development of an antenna array with reconfigurable transmission line feeds connecting each element in series. In particular, 2D traveling wave array employing trapezoidal Dielectric Wedge for Beam Steering will be discussed. The presentation includes current status of the effort and suggested future work. The work is being done as part of the NASA Office of the Chief Technologist's Space Technology Research Fellowship (NSTRF).

  8. 46 CFR 58.25-70 - Steering-gear control systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Steering-gear control systems. 58.25-70 Section 58.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY MACHINERY AND RELATED SYSTEMS Steering Gear § 58.25-70 Steering-gear control systems. (a) Each power-driven steering-gear system must be...

  9. 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.

  10. 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.

  11. Beam steering by computer generated hologram for optical switches

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Keita; Suzuki, Kenya; Yamaguchi, Joji

    2016-02-01

    We describe a computer generated hologram (CGH) method for application to a multiple input and multiple output (MxN) optical switch based on a liquid crystal on silicon (LCOS). The conventional MxN optical switch needs multiple spatial light modulations. However, the CGH method realizes an MxN optical switch simply with a one-time spatial light modulation, resulting in fewer optical elements and better cost efficiency. Moreover, the intrinsic loss of the proposed MxN switch resulting from beam splitting can be reduced by routing multiple signals with a single knob control, which is called a multi-pole multi-throw switch. In this paper, we demonstrate a 5x5 wavelength selective switch (WSS) and a 2-degree ROADM that we realized using the above CGH method. The experimental results indicate that these switches work well with a crosstalk of < -14.9 dB.

  12. Einstein-Podolsky-Rosen paradox and quantum steering in a three-mode optomechanical system

    NASA Astrophysics Data System (ADS)

    He, Qiongyi; Ficek, Zbigniew

    2014-02-01

    We study multipartite entanglement, the generation of Einstein-Podolsky-Rosen (EPR) states, and quantum steering in a three-mode optomechanical system composed of an atomic ensemble located inside a single-mode cavity with a movable mirror. The cavity mode is driven by a short laser pulse, has a nonlinear parametric-type interaction with the mirror and a linear beam-splitter-type interaction with the atomic ensemble. There is no direct interaction of the mirror with the atomic ensemble. A threshold effect for the dynamics of the system is found, above which the system works as an amplifier and below which as an attenuator of the output fields. The threshold is determined by the ratio of the coupling strengths of the cavity mode to the mirror and to the atomic ensemble. It is shown that above the threshold, the system effectively behaves as a two-mode system in which a perfect bipartite EPR state can be generated, while it is impossible below the threshold. Furthermore, a fully inseparable tripartite entanglement and even further a genuine tripartite entanglement can be produced above and below the threshold. In addition, we consider quantum steering and examine the monogamy relations that quantify the amount of bipartite steering that can be shared between different modes. It is found that the mirror is more capable for steering of entanglement than the cavity mode. The two-way steering is found between the mirror and the atomic ensemble despite the fact that they are not directly coupled to each other, while it is impossible between the output of cavity mode and the ensemble which are directly coupled to each other.

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

    NASA Astrophysics Data System (ADS)

    Krantz, Harry; Wiencke, Lawrence

    2016-03-01

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

  14. Fully integrated hybrid silicon free-space beam steering source with 32-channel phased array

    NASA Astrophysics Data System (ADS)

    Hulme, J. C.; Doylend, J. K.; Heck, M. J. R.; Peters, J. D.; Davenport, M. L.; Bovington, J. T.; Coldren, L. A.; Bowers, J. E.

    2014-03-01

    Free-space beam steering using optical phased arrays is a promising method for implementing free-space communication links and Light Detection and Ranging (LIDAR) without the sensitivity to inertial forces and long latencies which characterize moving parts. Implementing this approach on a silicon-based photonic integrated circuit adds the additional advantage of working with highly developed CMOS processing techniques. In this work we discuss our progress in the development of a fully integrated 32 channel PIC with a widely tunable diode laser, a waveguide phased array, an array of fast phase modulators, an array of hybrid III-V/silicon amplifiers, surface gratings, and a graded index lens (GRIN) feeding an array of photodiodes for feedback control. The PIC has been designed to provide beam steering across a 15°x5° field of view with 0.6°x0.6° beam width and background peaks suppressed 15 dB relative to the main lobe within the field of view for arbitrarily chosen beam directions. Fabrication follows the hybrid silicon process developed at UCSB with modifications to incorporate silicon diodes and a GRIN lens.

  15. High-contrast grating MEMS optical phase-shifters for two-dimensional free-space beam steering

    NASA Astrophysics Data System (ADS)

    Megens, Mischa; Yoo, Byung-Wook; Chan, Trevor; Yang, Weijian; Sun, Tianbo; Chang-Hasnain, Connie J.; Wu, Ming C.; Horsley, David A.

    2014-02-01

    We report an optical phased array (OPA) for two-dimensional free-space beam steering. The array is composed of tunable MEMS all-pass filters (APFs) based on polysilicon high contrast grating (HCG) mirrors. The cavity length of each APF is voltage controlled via an electrostatically-actuated HCG top mirror and a fixed DBR bottom mirror. The HCG mirrors are composed of only a single layer of polysilicon, achieving >99% reflectivity through the use of a subwavelength grating patterned into the polysilicon surface. Conventional metal-coated MEMS mirrors must be thick (1-50 μm) to prevent warpage arising from thermal and residual stress. The single material construction used here results in a high degree of flatness even in a thin 350 nm HCG mirror. Relative to beamsteering systems based on a single rotating MEMS mirror, which are typically limited to bandwidths below 50 kHz, the MEMS OPA described here has the advantage of greatly reduced mass and therefore achieves a bandwidth over 500 kHz. The APF structure affords large (~2π) phase shift at a small displacement (< 50 nm), an order-of-magnitude smaller than the displacement required in a single-mirror phase-shifter design. Precise control of each all-pass-filter is achieved through an interferometric phase measurement system, and beam steering is demonstrated using binary phase patterns.

  16. Ultra-Wideband, Dual-Polarized, Beam-Steering P-Band Array Antenna

    NASA Technical Reports Server (NTRS)

    duToit, Cornelis

    2014-01-01

    A dual-polarized, wide-bandwidth (200 MHz for one polarization, 100 MHz for the orthogonal polarization) antenna array at P-band was designed to be driven by NASA's EcoSAR digital beam former. EcoSAR requires two wide P-band antenna arrays mounted on the wings of an aircraft, each capable of steering its main beam up to 35deg off-boresight, allowing the twin radar beams to be steered at angles to the flight path. The science requirements are mainly for dual-polarization capability and a wide bandwidth of operation of up to 200 MHz if possible, but at least 100 MHz with high polarization port isolation and low cross-polarization. The novel design geometry can be scaled with minor modifications up to about four times higher or down to about half the current design frequencies for any application requiring a dual-polarized, wide-bandwidth steerable antenna array. EcoSAR is an airborne interferometric P-band synthetic aperture radar (SAR) research application for studying two- and three-dimensional fine-scale measurements of terrestrial ecosystem structure and biomass, which will ultimately aid in the broader study of the carbon cycle and climate change. The two 2×8 element Pband antenna arrays required by the system will be separated by a baseline of about 25 m, allowing for interferometry measurements. The wide 100-to- 200-MHz bandwidth dual-polarized beams employed will allow the determination of the amount of biomass and even tree height on the ground. To reduce the size of the patches along the boresight dimension in order to fit them into the available space, two techniques were employed. One technique is to add slots along the edges of each patch where the main electric currents are expected to flow, and the other technique is to bend the central part of the patch away from the ground plane. The latter also facilitates higher mechanical rigidity. The high port isolation of more than 40 dB was achieved by employing a highly symmetrical feed mechanism for each

  17. The influence of wavelength in extinction measurements and beam steering in laser-induced incandescence measurements in sooting flames

    NASA Astrophysics Data System (ADS)

    Zerbs, J.; Geigle, K. P.; Lammel, O.; Hader, J.; Stirn, R.; Hadef, R.; Meier, W.

    2009-09-01

    The accuracy of laser-induced incandescence (LII) measurements is significantly influenced by the calibration process and the laser profile degradation due to beam steering. Additionally, the wavelength used for extinction measurements, needed for LII calibration, is critical and should be kept as high as possible in order to avoid light absorption by molecular species in the flame. The influence of beam steering on the LII measurement was studied in turbulent sooting C2H4/air flames at different pressures. While inhomogeneities in the laser profile become smoothed out in time-averaged measurements, especially at higher pressure, the corresponding single-shot beam profiles reveal an increasing effect of beam steering. In the current configuration it was observed that the resulting local laser fluence remains within certain limits (30% to 200%) of the original value. A sufficiently high incident laser fluence can thus prevent the local fluence from dropping below the LII threshold value of approximately 0.3 J/cm2 at the cost of increased soot surface vaporization. A spatial resolution in the dimension of the sheet thickness of below 1 mm cannot be guaranteed at increased pressure of 9 bars due to beam steering. A feasibility study in a combustor at technical conditions demonstrates the influence of both effects beam steering and choice of calibration wavelength and led to the conclusion that, however, a shot-to-shot calibration of LII with simultaneously measured extinction can be realized.

  18. Experimental analysis of beam aiming and pointing system with phased only spatial light modulators

    NASA Astrophysics Data System (ADS)

    Shi, Yubin; Feng, Guobin; Si, Lei

    2015-05-01

    In this paper, an advanced non-mechanical beam aiming and pointing system is presented. Traditional beam steering is based on the mechanical systems. In the complex and expensive systems, beam jittering and many other problems are major limitations. However, beam steering with optical phased array (OPA) devices can realize agile beam control with random access pointing and high efficiency. Our system is mainly based on phased only spatial light modulators (SLM), which can realize beam steering non-mechanically. Based on the conventional one dimensional beam steering method of SLM, two dimensional beam steering method was presented at first in order to demonstrate the feasibility of the whole system. Then the whole system was tested. Our beam steering system can steer beam to a target which was moving at the speed of 3.8mrad/s within the field of view. The RMS error of the system was 0.0246mrad in one dimension, and 0.139mrad in two dimension respectively. Meanwhile the whole process was recorded by another camera in order to show the results.

  19. Analysis of beam steering by diffraction and the scattering of light by turbulence

    NASA Astrophysics Data System (ADS)

    Tsui, Jing M.

    This thesis addresses two problems. The first is the performance of non-mechanical beam steering devices based on diffractive optics, and the second is the problem of the scattering of light by turbulence. Two beam steering devices namely holographic optical elements and optical phased arrays are analyzed. Of particular interest are the wavelength selectivity of the uniform volume holographic grating and the impact of dispersion on the spatial and temporal fidelity of an optically transmitted communication signal through both beamsteering devices. Longitudinal refractive index modulation (apodization) in photosensitive glass is used to improve sidelobe. Theoretical methods are developed to model both devices. For uniform grating, it is shown that the temporal dispersion due to the diffraction increase with beam diameter yielding a higher power penalty for large diffraction angles and aperture sizes. For an optical phased array, it is shown the power penalty increase as the diffraction angles and diameters increase. In addition, the scattering of light in turbulent medium is investigated. Of particular interest is to determine region of validity of the Born approximation which is used to compute the scattering field. Pade approximants are used to analyze the propagation through a media having strong turbulent intensity. It is shown that the region of convergence of Born approximation increases as the outer scale of the turbulence decreases. In the case of the strong turbulence, the Born approximation does not capture the correct angular distribution of the scattering intensity.

  20. Beam steering in superconducting quarter-wave resonators: An analytical approach

    NASA Astrophysics Data System (ADS)

    Facco, Alberto; Zvyagintsev, Vladimir

    2011-07-01

    Beam steering in superconducting quarter-wave resonators (QWRs), which is mainly caused by magnetic fields, has been pointed out in 2001 in an early work [A. Facco and V. Zviagintsev, in Proceedings of the Particle Accelerator Conference, Chicago, IL, 2001 (IEEE, New York, 2001), p. 1095], where an analytical formula describing it was proposed and the influence of cavity geometry was discussed. Since then, the importance of this effect was recognized and effective correction techniques have been found [P. N. Ostroumov and K. W. Shepard, Phys. Rev. ST Accel. Beams 4, 110101 (2001)PRABFM1098-440210.1103/PhysRevSTAB.4.110101]. This phenomenon was further studied in the following years, mainly with numerical methods. In this paper we intend to go back to the original approach and, using well established approximations, derive a simple analytical expression for QWR steering which includes correction methods and reproduces the data starting from a few calculable geometrical constants which characterize every cavity. This expression, of the type of the Panofski equation, can be a useful tool in the design of superconducting quarter-wave resonators and in the definition of their limits of application with different beams.

  1. Catheter steering using a Magnetic Resonance Imaging system.

    PubMed

    Lalande, Viviane; Gosselin, Frederick P; Martel, Sylvain

    2010-01-01

    A catheter is successfully bent and steered by applying magnetic gradients inside a Magnetic Resonance Imaging system (MRI). One to three soft ferromagnetic spheres are attached at the distal tip of the catheter with different spacing between the spheres. Depending on the interactions between the spheres, progressive or discontinuous/jumping displacement was observed for increasing magnetic load. This phenomenon is accurately predicted by a simple theoretical dipole interaction model. PMID:21096567

  2. Steering magnet power supply control system for the TRISTAN AR

    SciTech Connect

    Kubo, T.; Endo, K.; Fukuma, H.; Kabe, A.; Ozaki, T.

    1985-10-01

    The closed orbit distortion of TRISTAN Accumulation Ring (AR) is corrected by the steering magnets (correction dipole magnets). These magnets are excited by the bipolar power supplies with the rated power of about 1 KVA. The power supplies are controlled remotely through the serial camac dataway. The camac modules which include the microprocessor are developed for this system and these modules send out the reference current patterns to the individual power supply.

  3. 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. PMID:23482053

  4. Polymeric waveguide electro-optic beam-steering device with DNA biopolymer conductive cladding layers

    NASA Astrophysics Data System (ADS)

    Aga, Roberto S.; Ouchen, Fahima; Lesko, Alyssa; Telek, Brian A.; Fehrman Cory, Emily M.; Bartsch, Carrie M.; Lombardi, Jack; Grote, James; Heckman, Emily M.

    2012-11-01

    A polymer electro-optic (EO) waveguide beam-steering device with deoxyribonucleic acid (DNA) biopolymer conductive cladding layers and a core layer of the commercially available EO polymer SEO100 is demonstrated with 100% relative poling efficiency. This demonstration device exhibits a deflection efficiency of 99 mrad/kV with a corresponding in-device EO coefficient r33 of 124 pm/V at 1550 nm. When the DNA biopolymer bottom cladding layer is replaced by the commonly used cladding polymer UV15, the deflection efficiency and in-device r33 drop to 34 mrad/kV and 43 pm/V, respectively.

  5. All-Optical Steering of Laser-Wakefield-Accelerated Electron Beams

    SciTech Connect

    Popp, A.; Osterhoff, J.; Major, Zs.; Hoerlein, R.; Fuchs, M.; Weingartner, R.; Krausz, F.; Gruener, F.; Karsch, S.; Vieira, J.; Marti, M.; Fonseca, R. A.; Martins, S. F.; Silva, L. O.

    2010-11-19

    We investigate the influence of a tilted laser-pulse-intensity front on laser-wakefield acceleration. Such asymmetric light pulses may be exploited to obtain control over the electron-bunch-pointing direction and in our case allowed for reproducible electron-beam steering in an all-optical way within an 8 mrad opening window with respect to the initial laser axis. We also discovered evidence of collective electron-betatron oscillations due to off-axis electron injection into the wakefield induced by a pulse-front tilt. These findings are supported by 3D particle-in-cell simulations.

  6. All-optical steering of laser-wakefield-accelerated electron beams.

    PubMed

    Popp, A; Vieira, J; Osterhoff, J; Major, Zs; Hörlein, R; Fuchs, M; Weingartner, R; Rowlands-Rees, T P; Marti, M; Fonseca, R A; Martins, S F; Silva, L O; Hooker, S M; Krausz, F; Grüner, F; Karsch, S

    2010-11-19

    We investigate the influence of a tilted laser-pulse-intensity front on laser-wakefield acceleration. Such asymmetric light pulses may be exploited to obtain control over the electron-bunch-pointing direction and in our case allowed for reproducible electron-beam steering in an all-optical way within an 8 mrad opening window with respect to the initial laser axis. We also discovered evidence of collective electron-betatron oscillations due to off-axis electron injection into the wakefield induced by a pulse-front tilt. These findings are supported by 3D particle-in-cell simulations. PMID:21231309

  7. Correction of vignetting and distortion errors induced by two-axis light beam steering

    PubMed Central

    Gao, Liang; Tkaczyk, Tomasz S.

    2012-01-01

    A mirror facet’s angle correction approach is presented for eliminating pupil plane distortions and sub-field image vignetting in the image mapping spectrometry (IMS). The two-axis light reflection problem on the image mapper is solved and a rigorous analytical solution is provided. The cellular fluorescence imaging experiment demonstrates that, with an angle-corrected image mapper, the acquired image quality of spectral channels has been significantly improved compared to previous IMS images. The proposed mathematical model can also be used in solving general two-axis beam steering problems for instruments with active optical mirrors. PMID:24976654

  8. Planar laser-induced incandescence of turbulent sooting flames: the influence of beam steering and signal trapping

    NASA Astrophysics Data System (ADS)

    Sun, Z. W.; Alwahabi, Z. T.; Gu, D. H.; Mahmoud, S. M.; Nathan, G. J.; Dally, B. B.

    2015-03-01

    The influence of beam steering and signal trapping on the accuracy of soot volume fractions measured using planar laser-induced incandescence (LII) has been investigated in turbulent non-premixed sooting flames at atmospheric pressure. In turbulent non-premixed C2H4/air flames, the influence of local de-focusing/focusing of the laser sheet from beam steering can result in the underestimate of the averaged LII signal by 30 %, even when operating within the so-called plateau regime of laser fluence. Beam steering was also found to be significant in both the upstream region of C2H4/air flames and non-reacting C2H4 flows, because the fuel has a relatively high refractive index compared with ambient air. The extent of beam steering at different heights of reacting and isothermal flows as well as its dependence on exit Reynolds number (Re) has been measured. The measurements reveal that even at low turbulence levels (2000 < Re < 3000), beam steering effects can be significant. Also found is that the LII signal at a 450 nm wavelength can be attenuated by a few per cent at high soot loading regions in turbulent flames due to signal trapping. Finally, the feasibility of directly evaluating the signal attenuation via planar LII results was assessed by comparing the virtual soot attenuation calculated based on the planar LII result with that measured using light-of-sight extinction.

  9. 46 CFR 115.814 - Steering systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... for the service intended. Servo-type power systems, such as orbitrol systems, must be tested and capable of smooth operation by a single person in the manual mode, with hydraulic pumps secured....

  10. 46 CFR 115.814 - Steering systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... for the service intended. Servo-type power systems, such as orbitrol systems, must be tested and capable of smooth operation by a single person in the manual mode, with hydraulic pumps secured....

  11. 46 CFR 115.814 - Steering systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... for the service intended. Servo-type power systems, such as orbitrol systems, must be tested and capable of smooth operation by a single person in the manual mode, with hydraulic pumps secured....

  12. 46 CFR 115.814 - Steering systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... for the service intended. Servo-type power systems, such as orbitrol systems, must be tested and capable of smooth operation by a single person in the manual mode, with hydraulic pumps secured....

  13. 46 CFR 115.814 - Steering systems.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... for the service intended. Servo-type power systems, such as orbitrol systems, must be tested and capable of smooth operation by a single person in the manual mode, with hydraulic pumps secured....

  14. Development of fast steering mirror control system for plasma heating and diagnostics

    SciTech Connect

    Okada, K. Kubo, S.; Shimozuma, T.; Yoshimura, Y.; Igami, H.; Takahashi, H.; Tanaka, K.; Kobayashi, S.; Ito, S.; Mizuno, Y.; Ogasawara, S.; Nishiura, M.

    2014-11-15

    A control system for a fast steering mirror has been newly developed for the electron cyclotron heating (ECH) launchers in the large helical device. This system enables two-dimensional scan during a plasma discharge and provides a simple feedback control function. A board mounted with a field programmable gate array chip has been designed to realize feedback control of the ECH beam position to maintain higher electron temperature by ECH. The heating position is determined by a plasma diagnostic signal related to the electron temperature such as electron cyclotron emission and Thomson scattering.

  15. Development of fast steering mirror control system for plasma heating and diagnostics.

    PubMed

    Okada, K; Nishiura, M; Kubo, S; Shimozuma, T; Yoshimura, Y; Igami, H; Takahashi, H; Tanaka, K; Kobayashi, S; Ito, S; Mizuno, Y; Ogasawara, S

    2014-11-01

    A control system for a fast steering mirror has been newly developed for the electron cyclotron heating (ECH) launchers in the large helical device. This system enables two-dimensional scan during a plasma discharge and provides a simple feedback control function. A board mounted with a field programmable gate array chip has been designed to realize feedback control of the ECH beam position to maintain higher electron temperature by ECH. The heating position is determined by a plasma diagnostic signal related to the electron temperature such as electron cyclotron emission and Thomson scattering. PMID:25430376

  16. Digital Beam Steering Device Based on Decoupled Birefringent Prism Deflector and Polarization Rotator

    NASA Technical Reports Server (NTRS)

    Pishnyak, Oleg; Kreminska, Lyubov; Laventovich, Oleg D.; Pouch, John J.; Miranda, Felix A.; Winker, Bruce K.

    2004-01-01

    We describe digital beam deflectors (DBDs) based on liquid crystals. Each stage of the device comprises a polarization rotator and a birefringent prism deflector. The birefringent prism deflects the beam by an angle that depends on polarization of the incident beam. The prism can be made of the uniaxial smectic A (SmA) liquid crystal (LC) or a solid crystal such as yttrium orthovanadate (YVO4). SmA prisms have high birefringence and can be constructed in a variety of shapes, including single prisms and prismatic blazed gratings of different angles and profiles. We address the challenges of uniform alignment of SmA, such as elimination of focal conic domains. Rotation of linear polarization is achieved by an electrically switched twisted nematic (TN) cell. A DBD composed of N rotator-deflector pairs steers the beam into 2(sup N) directions. As an example, we describe a four-stage DBD deflecting normally incident laser beam within the range of +/- 56 mrad with 8 mrad steps. Redirection of the beam is achieved by switching the TN cells.

  17. High-performance beam steering using electrowetting-driven liquid prism fabricated by a simple dip-coating method

    NASA Astrophysics Data System (ADS)

    Enrico Clement, Carlos; Park, Sung-Yong

    2016-05-01

    A high degree of beam steering is demonstrated using an electrowetting-driven liquid prism. While prism devices have typically relied on complex and expensive laboratory setups, such as high-vacuum facilities for fabrication of dielectric layers, this work utilizes a simple dip-coating method to provide an ion gel layer as a dielectric, offering 2 or 3 orders higher specific capacitance (c ≈ 10 μF/cm2) than that of conventional dielectrics. Analytical studies present the effects of liquid selection and arrangement on overall prism performance. For experimental demonstrations of high-performance beam steering, we not only selected two immiscible liquids of water and 1-bromonaphthalene (1-BN) oil which provide the large refractive index difference (nwater = 1.33 and n1-BN = 1.65 at λ = 532 nm) between them, but also utilized a double-stacked prism configuration which increases the number of interfaces for incoming light to be steered. At a prism apex angle of φ = 27°, we were able to achieve significantly large beam steering of up to β = 19.06°, which is the highest beam steering performance ever demonstrated using electrowetting technology.

  18. High power microwave beam steering based on gyromagnetic nonlinear transmission lines

    SciTech Connect

    Romanchenko, I. V. Rostov, V. V.; Gunin, A. V.; Konev, V. Yu.

    2015-06-07

    We demonstrate electronically controlled beam steering by high power RF pulses produced by two gyromagnetic nonlinear transmission lines (NLTLs) connected to a one high voltage driver. Each NLTL is capable of producing several ns RF pulses with peak power from 50 to 700 MW (6% standard deviation) at frequencies from 0.5 to 1.7 GHz (1% standard deviation) with 100 Hz repetition rate. Using a helix antenna allows irradiating of RF pulses with almost circular polarization and 350 MW maximum peak power, which corresponds to 350 kV effective potential of radiation. At the installation of two identical channels, we demonstrate the possibility of beam steering within ±15° in the horizontal plane by coherent RF pulses with circular polarization at 1.0 GHz center frequency. Fourfold increase in the power flux density for in-phase irradiation of RF pulses is confirmed by comparison with one-channel operation.

  19. New design of a beam-steering thermooptic multimode polymer waveguide switch

    NASA Astrophysics Data System (ADS)

    Ma, C.; van Keuren, E.

    2006-12-01

    We present simulations of a Y-branch directional coupler activated using the thermooptic effect in a multimode polymer waveguide. Microheaters embedded beneath both sides of the waveguide at the Y-branch are used to generate an inhomogeneous temperature profile. Through the thermooptic effect, this temperature profile creates a refractive index profile in the channel waveguide material, which steers the beam to one of the two output branches. We determined the expected thermal profiles using finite element modeling (FEM). The transmission of a basic mode through the waveguide was then simulated using the beam propagation method (BPM). The results show that a high contrast ratio (>90%) can be achieved in response times on the order of 1 ms.

  20. Focusing, wavelength tuning, beam steering and beam shaping of circular grating surface emitting distributed Bragg reflector lasers

    NASA Astrophysics Data System (ADS)

    Penner, Robert Scott

    Over the past decade, circular grating surface emitting DBR lasers (CGSELs) have progressed from theory to reality. These devices possess several properties that make them attractive options for such applications as optical interconnects and laser arrays. These advantages include low divergence angles, circular beam profiles, and high power output. In this dissertation, the addition of new functionality to these lasers including wavelength tunability, focusing, beam steering and beam shaping is investigated. The theory governing device operation is presented. Pertinent discussions include the coupled mode equations, grating coupling, focusing and changes to the effective index of refraction resulting from current injection through a transparent electrode on the grating. The development and refinement of the device fabrication process is detailed. Key milestones in the grating writing process included achieving first order gratings (Λ = 0.15 μm), creating chirped period gratings for focusing and optimizing the linewidth and uniformity of the grating for high power devices. Of equal importance in obtaining high efficiency devices was the reactive ion etch process. Two different etch recipes were developed: one for mesa-definition and a shallower grating-defining etch. Significant evaluation of the electrical and optical properties of the transparent electrode, Indium Tin Oxide, was performed. Incorporating ITO into the fabrication process required optimization of deposition, patterning, etching and annealing. Device performance, efficiency and functionality improved with each generation. Consequentially, over 225 mW of output power for a injection current of 600 mA, or a slope efficiency of 0.43 mW/mA, was produced by the final generation of high power CGSELs. Focusing was demonstrated by the creation of individual devices with different focal lengths. Coarse mode selection was obtained by removing radial segments of the circular grating thereby eliminating both

  1. Modeling of accelerator systems and experimental verification of Quarter-Wave Resonator steering

    NASA Astrophysics Data System (ADS)

    Benatti, Carla

    beam pipe, which has the potential to induce steering on the beam. These additional complications make this a significant device to study in order to optimize the accelerator's overall performance. The NSCL and ReA, along with FRIB, are first introduced to provide background and motivate the central modeling objectives presented throughout this work. In the next chapter, underlying beam physics principles are then discussed, as they form the basis from which modeling methods are derived. The modeling methods presented include multi-particle tracking and beam envelope matrix transport. The following chapter investigates modeling elements in more detail, including quadrupoles, solenoids, and coaxial accelerating cavities. Assemblies of accelerator elements, or lattices, have been modeled as well, and a method for modeling multiple charge state transport using linear matrix methods is also given. Finally, an experiment studying beam steering induced by QWR resonators is presented, the first systematic experimental investigation of this effect. As mentioned earlier, characterization of this steering on beam properties is important for accurate modeling of the beam transport through the linac. The measurement technique devised at ReA investigates the effect's dependence on the beam's vertical offset within the cavity, the cavity amplitude, and the beam energy upon entrance into the cavity. The results from this experiment agree well with the analytical predictions based on geometrical parameters calculated from on-axis field profiles. The incorporation of this effect into modeling codes has the potential to speed up complex accelerator operations and tuning procedures in systems using QWRs.

  2. Optical modulators and beam steering based on electrically tunable plasmonic material

    NASA Astrophysics Data System (ADS)

    Shi, Kaifeng; Lu, Zhaolin

    2015-01-01

    Surface plasmon based photonic (or plasmonic) circuits merge electronics and photonics at the nanoscale, creating the ability to combine the superior technical advantages of photonics and electronics on the same chip. Recent work has demonstrated their remarkable applications in subwavelength optics, data storage and transmission, light harvesting and generation, and microscopy, as well as bioapplications. Plasmonics has become one of the most intensive research subjects in recent years, and much effort has been made to develop novel and efficient waveguiding structures and plasmonic materials. We will first review some major progress in subwavelength plasmonic waveguides and plasmonic materials. Then, focusing on the applications of a class of promising alternative plasmonic materials, transparent conducting oxides, we will introduce some of our up-to-date study, especially on electro-absorption modulators and beam steering.

  3. Highly bent (110) Ge crystals for efficient steering of ultrarelativistic beams

    SciTech Connect

    De Salvador, D.; Maggioni, G.; Carturan, S.; Bazzan, M.; Argiolas, N.; Carnera, A.; Dalla Palma, M.; Della Mea, G.; Bagli, E.; Mazzolari, A.; Bandiera, L.; Guidi, V.; Lietti, D.; Berra, A.; Guffanti, G.; Prest, M.; Vallazza, E.

    2013-10-21

    Thanks to the effective electrostatic potential generated by the ordered atomic structure, bent crystals can efficiently deflect ultra relativistic charged beams by means of planar and axial channeling phenomena as well as of the recently discovered volume reflection effect. Most of the experimental knowledge about these phenomena has been gathered with Si crystals, but it has been recently demonstrated that the steering performance can be improved by using high quality Ge materials which have a larger atomic number. In this paper, we investigate channeling and volume reflection of 400 GeV protons from (110) lattice planes in highly bent Ge strips crystals. Both production and characterization of the strips are presented. Herein, the experimental results on deflection are compared with theoretical predictions, with previous published data and with the expected performances of Si crystals in similar experimental conditions.

  4. 46 CFR 185.320 - Steering gear, controls, and communication system tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Steering gear, controls, and communication system tests... gear, controls, and communication system tests. The master of a vessel shall have examined and tested the steering gear, signaling whistle, propulsion controls, and communication systems of the...

  5. 46 CFR 122.320 - Steering gear, controls, and communication system tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Steering gear, controls, and communication system tests... communication system tests. The master of a vessel shall have examined and tested the steering gear, signaling whistle, propulsion controls, and communication systems of the vessel prior to getting underway for...

  6. 46 CFR 122.320 - Steering gear, controls, and communication system tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Steering gear, controls, and communication system tests... communication system tests. The master of a vessel shall have examined and tested the steering gear, signaling whistle, propulsion controls, and communication systems of the vessel prior to getting underway for...

  7. Designing Beam Steering for Accurate Measurement of Intima-Media Thickness at Carotid Sinus

    NASA Astrophysics Data System (ADS)

    Mashiyama, Takashi; Hasegawa, Hideyuki; Kanai, Hiroshi

    2006-05-01

    Recently, cardiovascular disease has become the second most common cause of death in Japan following malignant neoplasm formation. Therefore, it is necessary to diagnose atherosclerosis during its early stages because atherosclerosis is one of the main causes of cardiovascular diseases. The carotid sinus is a site that is easily affected by atherosclerosis [C. K. Zarins et al.: Circ. Res. 53 (1983) 502]; therefore, the diagnosis of this disease at this site is important [S. C. Nicholls et al.: Stroke 20 (1989) 175]. However, it is difficult to accurately diagnose atherosclerosis in the carotid sinus in the long-axis plane, which is parallel to the axis of the vessel, using conventional linear scanning because the carotid sinus is not flat along the axis of the vessel, and the ultrasonic beams used in linear scanning are perpendicular to the arterial wall in a limited region. Echoes from regions that are not perpendicular to the ultrasonic beams are very weak and the arterial wall in such regions is hardly recognized in a B-mode image. In this study, the position of the arterial wall was predetermined on the basis of the B-mode image obtained by conventional linear scanning, then ultrasonic beams were transmitted again so that all beams were almost perpendicular to the arterial wall. In basic experiments, a nonflat object made of silicone rubber was measured and it was shown that it is possible to image a nonflat object over the entire scanned area using the proposed beam steering method. Furthermore, in in vivo experiments, the intima-media complex was imaged over the entire scanned area at the carotid sinus.

  8. Switched steerable multiple beam antenna system

    NASA Astrophysics Data System (ADS)

    Iwasaki, Richard S.

    1988-09-01

    A steerable multibeam five element cross-feed cluster antenna system is described. The feed power is divided into five branches. Each branch includes a switching network comprised of a plurality of time delay elements each individually controlled by a respective electromagnetic latching switch. Frequency independent individual two-dimensional beam steering at intermediate (IF) scanning frequencies is thereby provided wherein discrete incremental time delays are introduced by the switching networks into each branch and the signals recombined thereafter to form each beam. The electromagnetic latched switching reduces power consumption and permits higher power switching and reciprocal coincident tranmsit and receive operation. Frequency independence due to incremental time delay switching permits coincident reciprocal operation and steering for transmit-receive signal paths carrying different transmit-receive frequencies. Diagonal quarter wave plates in the waveguides alter polarization from the circular to orthogonal linear to provide transmitter-receiver isolation.

  9. Analysing Finnish Steering System from the Perspective of Social Space: The Case of the "Campus University"

    ERIC Educational Resources Information Center

    Treuthardt, Leena; Valimaa, Jussi

    2008-01-01

    The present study analyses Finnish higher education steering system, management by results, from the perspective of higher education institutions. We ask what happens inside a higher education institution, called here the "Campus University", during the actual negotiations related to the national steering system. We analyse not only the management…

  10. Electron beam focusing system

    SciTech Connect

    Dikansky, N.; Nagaitsev, S.; Parkhomchuk, V.

    1997-09-01

    The high energy electron cooling requires a very cold electron beam. Thus, the electron beam focusing system is very important for the performance of electron cooling. A system with and without longitudinal magnetic field is presented for discussion. Interaction of electron beam with the vacuum chamber as well as with the background ions and stored antiprotons can cause the coherent electron beam instabilities. Focusing system requirements needed to suppress these instabilities are presented.

  11. Electron beam size measurements in the Fermilab Electron Cooling System

    SciTech Connect

    Kroc, T.K.; Burov, A.V.; Bolshakov, T.B.; Shemyakin, A.; Seletskiy, S.M.; /Rochester U.

    2005-09-01

    The Fermilab Electron Cooling Project requires a straight trajectory and constant beam size to provide maximum cooling of the antiprotons in the Recycler. A measurement system was developed using movable apertures and steering bumps to measure the beam size in a 20m long, nearly continuous, solenoid. This paper will focus on results of these measurements of the beam size and the difficulties in making those measurements.

  12. Electron Beam Size Measurements in the Fermilab Electron Cooling System

    SciTech Connect

    Kroc, T. K.; Burov, A. V.; Bolshakov, T. B.; Shemyakin, A.; Seletskiy, S. M.

    2006-03-20

    The Fermilab Electron Cooling Project requires a straight trajectory and constant beam size to provide maximum cooling of the antiprotons in the Recycler. A measurement system was developed using movable apertures and steering bumps to measure the beam size in a 20m long, nearly continuous, solenoid. This paper will focus on results of these measurements of the beam size and the difficulties in making those measurements.

  13. Ministerial Steering and Institutional Responses: Recent Developments of the Finnish Higher Education System in Germany.

    ERIC Educational Resources Information Center

    Holtta, Sepp; Rekila, Eila

    2003-01-01

    Studied recent changes in the higher education system of Finland through two studies, one on the change in governmental steering instruments from the mid-1980s to the present and one on the institutional reaction to the new steering-by-results model. Data from various sources provide details of the reformulation of higher education policy. (SLD)

  14. 46 CFR 185.320 - Steering gear, controls, and communication system tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Steering gear, controls, and communication system tests. 185.320 Section 185.320 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Miscellaneous Operating Requirements § 185.320 Steering gear, controls, and communication...

  15. A steering law for three double-gimbal control moment gyro systems

    NASA Technical Reports Server (NTRS)

    Yoshikawa, T.

    1975-01-01

    A steering law for three double-gimbal control moment gyro (CMG) systems is proposed. This steering law is applicable to systems with almost any configuration of CMGs and the CMG-out operation needs no special modification. Examples of three double gimbal CMG systems in an orthogonal configuration and in a parallel configuration are shown along with the results of digital simulations. Simulation results show that any command torque can always be met except when the system is in a singular state and that, whenever the system is in, or close to, a singularity, the steering law drives the system state out of the vicinity of the singularity.

  16. Diode laser lidar wind velocity sensor using a liquid-crystal retarder for non-mechanical beam-steering.

    PubMed

    Rodrigo, Peter John; Iversen, Theis F Q; Hu, Qi; Pedersen, Christian

    2014-11-01

    We extend the functionality of a low-cost CW diode laser coherent lidar from radial wind speed (scalar) sensing to wind velocity (vector) measurements. Both speed and horizontal direction of the wind at ~80 m remote distance are derived from two successive radial speed estimates by alternately steering the lidar probe beam in two different lines-of-sight (LOS) with a 60° angular separation. Dual-LOS beam-steering is implemented optically with no moving parts by means of a controllable liquid-crystal retarder (LCR). The LCR switches the polarization between two orthogonal linear states of the lidar beam so it either transmits through or reflects off a polarization splitter. The room-temperature switching time between the two LOS is measured to be in the order of 100 μs in one switch direction but 16 ms in the opposite transition. Radial wind speed measurement (at 33 Hz rate) while the lidar beam is repeatedly steered from one LOS to the other every half a second is experimentally demonstrated - resulting in 1 Hz rate estimates of wind velocity magnitude and direction at better than 0.1 m/s and 1° resolution, respectively. PMID:25401817

  17. Efficient multibeam large-angle nonmechanical laser beam steering from computer-generated holograms rendered on a liquid crystal spatial light modulator.

    PubMed

    Lindle, James R; Watnik, Abbie T; Cassella, Vincent A

    2016-06-01

    Multibeam large-angle beam steering is demonstrated in the visible spectral region by imprinting computer-generated holographic Fresnel zone plates on a liquid crystal spatial light modulator (SLM) configured as the first element of a telescope. The position and intensity of each beam are controlled independently. The laser beam is steered over a ±37° field of regard, with the power in the beam at 37° being greater than 50% of the on-axis power. The power delivered on axis for a single beam was 48% of the power incident on the SLM. The beam profile remained Gaussian over the full steering range, and the on-axis beam divergence is 2.1 mrad. PMID:27411184

  18. Use of Rayleigh imaging and ray tracing to correct for beam-steering effects in turbulent flames.

    PubMed

    Kaiser, Sebastian A; Frank, Jonathan H; Long, Marshall B

    2005-11-01

    Laser Rayleigh imaging has been applied in a number of flow and flame studies to measure concentration or temperature distributions. Rayleigh cross sections are dependent on the index of refraction of the scattering medium. The same index of refraction changes that provide contrast in Rayleigh images can also deflect the illuminating laser sheet. By applying a ray-tracing algorithm to the detected image, it is possible to correct for some of these beam-steering effects and thereby improve the accuracy of the measured field. Additionally, the quantification of the degree of beam steering through the flow provides information on the degradation of spatial resolution in the measurement. Application of the technique in a well-studied laboratory flame is presented, along with analysis of the effects of image noise and spatial resolution on the effectiveness of the algorithm. PMID:16270544

  19. Metamaterial loading of electrically small patch antennas to enable beam steering up to the horizon

    NASA Astrophysics Data System (ADS)

    Pai Raikar, Vandita Rajiv

    This thesis research has been conducted with an aim of investigating the effects of metamaterials on microstrip patch antennas. Metamaterials exhibit interesting properties such as single negative or simultaneous double negative values of relative permittivity and permeability, due to which they have gained immense popularity. The influence of metamaterials on traditional patch antennas has been a topic of focus throughout this research. Different metamaterial unit cells have been designed to possess satisfactory behavior in terms of permittivity and permeability. The use of metamaterials as a substrate for patch antennas has been explored, highlighting the possibility of designing electrically small patch antennas. Several metamaterial unit cells and modified patch antennas have been designed and modeled in Ansys HFSS, a highly competent full wave electromagnetic solver. On achieving a satisfactory results from a single patch antenna, the same concept has been applied to design a planar phased array patch antenna having 8x8 elements. The planar phased array antenna will be designed to enable beam steering from broadside toward the horizon.

  20. Visual Analytics for Complex Engineering Systems: Hybrid Visual Steering of Simulation Ensembles.

    PubMed

    Matković, Krešimir; Gračanin, Denis; Splechtna, Rainer; Jelović, Mario; Stehno, Benedikt; Hauser, Helwig; Purgathofer, Werner

    2014-12-01

    In this paper we propose a novel approach to hybrid visual steering of simulation ensembles. A simulation ensemble is a collection of simulation runs of the same simulation model using different sets of control parameters. Complex engineering systems have very large parameter spaces so a naïve sampling can result in prohibitively large simulation ensembles. Interactive steering of simulation ensembles provides the means to select relevant points in a multi-dimensional parameter space (design of experiment). Interactive steering efficiently reduces the number of simulation runs needed by coupling simulation and visualization and allowing a user to request new simulations on the fly. As system complexity grows, a pure interactive solution is not always sufficient. The new approach of hybrid steering combines interactive visual steering with automatic optimization. Hybrid steering allows a domain expert to interactively (in a visualization) select data points in an iterative manner, approximate the values in a continuous region of the simulation space (by regression) and automatically find the "best" points in this continuous region based on the specified constraints and objectives (by optimization). We argue that with the full spectrum of optimization options, the steering process can be improved substantially. We describe an integrated system consisting of a simulation, a visualization, and an optimization component. We also describe typical tasks and propose an interactive analysis workflow for complex engineering systems. We demonstrate our approach on a case study from automotive industry, the optimization of a hydraulic circuit in a high pressure common rail Diesel injection system. PMID:26356894

  1. Design and Control Implementation of AC Electric Power Steering System Test Bench*

    NASA Astrophysics Data System (ADS)

    Zhang, Weidong; Ai, Yibo

    Using AC motor is an important development trend of electric power steering system, and in this paper, we proposed a design of AC electric power steering system test bench. The paper introduced the bench structure, working principle and main components selection first, and then given the implementation scheme of test bench's three functions: simulation of the road resistance, power assistant control and data acquisition. The test results showed the feasibility of the test bench.

  2. Dynamic characterization and modelling of a dual-axis beam steering device for performance understanding, optimization and control design

    NASA Astrophysics Data System (ADS)

    Berglund, Martin; Palmer, Kristoffer; Lotfi, Sara; Kratz, Henrik; Thornell, Greger

    2013-04-01

    This paper presents a lumped thermal model of a dual-axis laser micromirror device for beam steering in a free-space optical (FSO) communication system, designed for fractionated spacecraft. An FSO communication system provides several advantages, such as larger bandwidth, smaller size and weight of the communication payload and less power consumption. A dual-axis mirror device is designed and realized using microelectromechanical systems technology. The fabrication is based on a double-sided, bulk micromachining process, where the mirror actuates thermally by joints consisting of v-grooves filled with the SU-8 polymer. The size of the device, consisting of a mirror, which is deflectable versus its frame in one direction, and through deflection of the frame in the other, is 15.4 × 10.4 × 0.3 mm3. In order to further characterize and understand the micromirror device, a Simulink state-space model of the actuator is set up using thermal and mechanical properties from a realized actuator. A deviation of less than 2% between the modelled and measured devices was obtained in an actuating temperature range of 20-200 °C. The model of the physical device was examined by evaluating its performance in vacuum, and by changing physical parameters, such as thickness and material composition. By this, design parameters were evaluated for performance gain and usability. For example, the crosstalk between the two actuators deflecting the mirror along its two axes in atmospheric pressure is projected to go down from 97% to 6% when changing the frame material from silicon to silicon dioxide. A feedback control system was also designed around the model in order to examine the possibility to make a robust control system for the physical device. In conclusion, the model of the actuator presented in this paper can be used for further understanding and development of the actuator system.

  3. Leaky wave antenna with amplitude controlled beam steering based on composite right/left-handed transmission lines

    NASA Astrophysics Data System (ADS)

    Eberspächer, M. A.; Eibert, T. F.

    2010-09-01

    An antenna comprising two different composite right/left-handed transmission line structures is proposed which enables easy beam steering at an operation frequency of 10 GHz. The composite right/left-handed transmission lines are based on planar, periodically arranged via free unit cells, implemented in microstrip technology. Both transmission lines exhibit the infinite wavelength phenomenon which occurs at 9.72 GHz and 9.89 GHz, respectively. Thus, operating the different leaky wave structures at 10 GHz, radiation with azimuth angles of ±8° and ±17° can be achieved depending on the selected input port. In order to obtain a tunable main beam direction, the radiation patterns of both structures are superimposed by feeding them simultaneously. The influence of each guiding structure, and hence the direction of the main beam, can be controlled via the feeding amplitude. As a result of this, the beam can be steered between ±17° with a gain of up to 10 dBi. The guiding structures are arranged in parallel with a clearance of a=12.2 mm which is less than half of the wavelength in free space. This allows in a further step the attachment of additional guiding structures in order to increase the tunable angle range or creating an antenna array with a small beamwidth in the elevation plane without the occurrence of grating lobes. An antenna prototype was fabricated and validated by measurements.

  4. 20 MHz Forward-imaging Single-element Beam Steering with an Internal Rotating Variable-Angle Reflecting Surface: Wire phantom and Ex vivo pilot study

    PubMed Central

    Raphael, David T.; Li, Xiang; Park, Jinhyoung; Chen, Ruimin; Chabok, Hamid; Barukh, Arthur; Zhou, Qifa; Elgazery, Mahmoud; Shung, K. Kirk

    2012-01-01

    Feasibility is demonstrated for a forward-imaging beam steering system involving a single-element 20 MHz angled-face acoustic transducer combined with an internal rotating variable-angle reflecting surface (VARS). Rotation of the VARS structure, for a fixed position of the transducer, generates a 2-D angular sector scan. If these VARS revolutions were to be accompanied by successive rotations of the single-element transducer, 3-D imaging would be achieved. In the design of this device, a single-element 20 MHz PMN-PT press-focused angled-face transducer is focused on the circle of midpoints of a micro-machined VARS within the distal end of an endoscope. The 2-D imaging system was tested in water bath experiments with phantom wire structures at a depth of 10 mm, and exhibited an axial resolution of 66 μm and a lateral resolution of 520 μm. Chirp coded excitation was used to enhance the signal-to-noise ratio, and to increase the depth of penetration. Images of an ex vivo cow eye were obtained. This VARS-based approach offers a novel forward-looking beam-steering method, which could be useful in intra-cavity imaging. PMID:23122968

  5. 20 MHz forward-imaging single-element beam steering with an internal rotating variable-angle reflecting surface: Wire phantom and ex vivo pilot study.

    PubMed

    Raphael, David T; Li, Xiang; Park, Jinhyoung; Chen, Ruimin; Chabok, Hamid; Barukh, Arthur; Zhou, Qifa; Elgazery, Mahmoud; Shung, K Kirk

    2013-02-01

    Feasibility is demonstrated for a forward-imaging beam steering system involving a single-element 20MHz angled-face acoustic transducer combined with an internal rotating variable-angle reflecting surface (VARS). Rotation of the VARS structure, for a fixed position of the transducer, generates a 2-D angular sector scan. If these VARS revolutions were to be accompanied by successive rotations of the single-element transducer, 3-D imaging would be achieved. In the design of this device, a single-element 20MHz PMN-PT press-focused angled-face transducer is focused on the circle of midpoints of a micro-machined VARS within the distal end of an endoscope. The 2-D imaging system was tested in water bath experiments with phantom wire structures at a depth of 10mm, and exhibited an axial resolution of 66μm and a lateral resolution of 520μm. Chirp coded excitation was used to enhance the signal-to-noise ratio, and to increase the depth of penetration. Images of an ex vivo cow eye were obtained. This VARS-based approach offers a novel forward-looking beam-steering method, which could be useful in intra-cavity imaging. PMID:23122968

  6. Design and Performance Evaluation of Optical Ethernet Switching Architecture with Liquid Crystal on Silicon-Based Beam-Steering Technology

    NASA Astrophysics Data System (ADS)

    Cheng, Yuh-Jiuh; Chou, H.-H.; Shiau, Yhi; Cheng, Shu-Ying

    2016-07-01

    A non-blocking optical Ethernet switching architecture with liquid crystal on a silicon-based beam-steering switch and optical output buffer strategies are proposed. For preserving service packet sequencing and fairness of routing sequence, priority and round-robin algorithms are adopted at the optical output buffer in this research. Four methods were used to implement tunable fiber delay modules for the optical output buffers to handle Ethernet packets with variable bit-rates. The results reported are based on the simulations performed to evaluate the proposed switching architecture with traffic analysis under a traffic model captured from a real-core network.

  7. Focused ion beam system

    DOEpatents

    Leung, K.; Gough, R.A.; Ji, Q.; Lee, Y.Y.

    1999-08-31

    A focused ion beam (FIB) system produces a final beam spot size down to 0.1 {mu}m or less and an ion beam output current on the order of microamps. The FIB system increases ion source brightness by properly configuring the first (plasma) and second (extraction) electrodes. The first electrode is configured to have a high aperture diameter to electrode thickness aspect ratio. Additional accelerator and focusing electrodes are used to produce the final beam. As few as five electrodes can be used, providing a very compact FIB system with a length down to only 20 mm. Multibeamlet arrangements with a single ion source can be produced to increase throughput. The FIB system can be used for nanolithography and doping applications for fabrication of semiconductor devices with minimum feature sizes of 0.1 m or less. 13 figs.

  8. Focused ion beam system

    DOEpatents

    Leung, Ka-Ngo; Gough, Richard A.; Ji, Qing; Lee, Yung-Hee Yvette

    1999-01-01

    A focused ion beam (FIB) system produces a final beam spot size down to 0.1 .mu.m or less and an ion beam output current on the order of microamps. The FIB system increases ion source brightness by properly configuring the first (plasma) and second (extraction) electrodes. The first electrode is configured to have a high aperture diameter to electrode thickness aspect ratio. Additional accelerator and focusing electrodes are used to produce the final beam. As few as five electrodes can be used, providing a very compact FIB system with a length down to only 20 mm. Multibeamlet arrangements with a single ion source can be produced to increase throughput. The FIB system can be used for nanolithography and doping applications for fabrication of semiconductor devices with minimum feature sizes of 0.1 .mu.m or less.

  9. Ion beam lithography system

    DOEpatents

    Leung, Ka-Ngo

    2005-08-02

    A maskless plasma-formed ion beam lithography tool provides for patterning of sub-50 nm features on large area flat or curved substrate surfaces. The system is very compact and does not require an accelerator column and electrostatic beam scanning components. The patterns are formed by switching beamlets on or off from a two electrode blanking system with the substrate being scanned mechanically in one dimension. This arrangement can provide a maskless nano-beam lithography tool for economic and high throughput processing.

  10. Ion beam accelerator system

    NASA Technical Reports Server (NTRS)

    Aston, G. (Inventor)

    1981-01-01

    A system is described that combines geometrical and electrostatic focusing to provide high ion extraction efficiency and good focusing of an accelerated ion beam. The apparatus includes a pair of curved extraction grids with multiple pairs of aligned holes positioned to direct a group of beamlets along converging paths. The extraction grids are closely spaced and maintained at a moderate potential to efficiently extract beamlets of ions and allow them to combine into a single beam. An accelerator electrode device downstream from the extraction grids is at a much lower potential than the grids to accelerate the combined beam. The application of the system to ion implantation is mentioned.

  11. Microhole Smart Steering and Logging While Drilling System

    SciTech Connect

    John Macpherson; Mathias Moeller; Thomas Gregg; Roland Chemali

    2006-06-30

    A background to Coiled Tubing Bottom Hole Assemblies (CT-BHA) is given, and the development of a resistivity measurement component, and a rib-steering motor component, is described. The successful operation of these components in both the laboratory and field environment is described. The primary conclusion of this development is that both components operate as anticipated within the CT-BHA, and significantly extend the possibility of drilling with coiled tubing in the microhole environment.

  12. Simulation of the Dynamic Behavior of Electric Power Steering Systems Using Dedicated Finite Elements

    NASA Astrophysics Data System (ADS)

    Besson, François; Ferraris, Guy; Guingand, Michèle; Vaujany, Jean-Pierre De

    During the last decade, many new technical solutions dedicated to the comfort of automotive vehicle's drivers have raised, like Electrical Power Steering (EPS). To fulfill the more and more demanding requirements in terms of vibration and acoustics, the dynamic behavior of the whole steering is studied. The system is divided into dedicated finite elements (FE) describing the whole steering. The stress was first put on the gears models (worm gear and rack-and-pinion) and their anti-backlash systems as they have been identified as potential vibration sources. Mechanical non-linearities (clearances, non-linear stiffness) of the mechanical system are taken into account in these models. Then, this model allows simulating the transient response of the system to an input excitation. Each developed element is validated using a fitted experimental test bench. Then, the general model is correlated the same way. Hence models can be used to study the dynamic behavior of EPS systems or sub-systems.

  13. Ion beam accelerator system

    NASA Technical Reports Server (NTRS)

    Aston, Graeme (Inventor)

    1984-01-01

    A system is described that combines geometrical and electrostatic focusing to provide high ion extraction efficiency and good focusing of an accelerated ion beam. The apparatus includes a pair of curved extraction grids (16, 18) with multiple pairs of aligned holes positioned to direct a group of beamlets (20) along converging paths. The extraction grids are closely spaced and maintained at a moderate potential to efficiently extract beamlets of ions and allow them to combine into a single beam (14). An accelerator electrode device (22) downstream from the extraction grids, is at a much lower potential than the grids to accelerate the combined beam.

  14. Postquantum Steering.

    PubMed

    Sainz, Ana Belén; Brunner, Nicolas; Cavalcanti, Daniel; Skrzypczyk, Paul; Vértesi, Tamás

    2015-11-01

    The discovery of postquantum nonlocality, i.e., the existence of nonlocal correlations that are stronger than any quantum correlations but nevertheless consistent with the no-signaling principle, has deepened our understanding of the foundations of quantum theory. In this work, we investigate whether the phenomenon of Einstein-Podolsky-Rosen steering, a different form of quantum nonlocality, can also be generalized beyond quantum theory. While post-quantum steering does not exist in the bipartite case, we prove its existence in the case of three observers. Importantly, we show that postquantum steering is a genuinely new phenomenon, fundamentally different from postquantum nonlocality. Our results provide new insight into the nonlocal correlations of multipartite quantum systems. PMID:26588364

  15. Infrared beam-steering using acoustically modulated surface plasmons over a graphene monolayer

    NASA Astrophysics Data System (ADS)

    Chen, P.-Y.; Farhat, M.; Askarpour, A. N.; Tymchenko, M.; Alù, A.

    2014-09-01

    We model and design a graphene-based infrared beamformer based on the concept of leaky-wave (fast traveling wave) antennas. The excitation of infrared surface plasmon polaritons (SPPs) over a ‘one-atom-thick’ graphene monolayer is typically associated with intrinsically ‘slow light’. By modulating the graphene with elastic vibrations based on flexural waves, a dynamic diffraction grating can be formed on the graphene surface, converting propagating SPPs into fast surface waves, able to radiate directive infrared beams into the background medium. This scheme allows fast on-off switching of infrared emission and dynamic tuning of its radiation pattern, beam angle and frequency of operation, by simply varying the acoustic frequency that controls the effective grating period. We envision that this graphene beamformer may be integrated into reconfigurable transmitter/receiver modules, switches and detectors for THz and infrared wireless communication, sensing, imaging and actuation systems.

  16. [Application of ICP-AES in automotive hydraulic power steering system fault diagnosis].

    PubMed

    Chen, Li-Dan

    2013-01-01

    The authors studied the innovative applications of the inductively coupled plasma-atomic emission spectrometry in automotive hydraulic power steering system fault diagnosis. After having determined Fe, Cu and Al content in the four groups of Buick Regal 2.4 main metal power-steering fluid whose travel course was respectively 2-9 thousand kilometers, 11-18 thousand kilometers, 22-29 thousandkilometers, and 31-40 thousand kilometers, and the database of primary metal content in the Buick Regal 2.4 different mileage power-steering fluid was established. The research discovered that the main metal content increased with increasing mileage and its normal level is between the two trend lines. Determination of the power-steering fluid main metal content and comparison with its database value can not only judge the wear condition of the automotive hydraulic power steering system and maintain timely to avoid the traffic accident, but also help the automobile detection and maintenance personnel to diagnose failure reasons without disintegration. This reduced vehicle maintenance costs, and improved service quality. PMID:23586258

  17. Real-time two-dimensional beam steering with gate-tunable materials: a theoretical investigation.

    PubMed

    Cheng, Jierong; Jafar-Zanjani, Samad; Mosallaei, Hossein

    2016-08-01

    A leaky-wave antenna is proposed that furnishes two-dimensional (2-D) beam scanning in both elevation and azimuth planes via electrical control in real time, and at a single frequency. The structure consists of a graphene sheet on a metal-backed substrate. The 2-D beam-scanning performance is achieved through the proper biasing configuration of graphene. Traditional pixel-by-pixel electrical control makes the biasing network a huge challenge for chip-scale designs in the terahertz regime and beyond. The method presented here enables dynamic control by applying two groups of one-dimensional biasing on the sides of the sheet. They are orthogonal and decoupled, with one group offering monotonic impedance variation along one direction, and the other sinusoidal impedance modulation along the other direction. The conductivity profile of the graphene sheet for a certain radiation angle, realized by applying proper voltage to each pad underneath the sheet, is determined by a holographic technique and can be reconfigured electronically and desirably. Such innovative biasing design makes real-time control of the beam direction and beamwidth simple and highly integrated. The concept is not limited to graphene-based structures, and can be generalized to any available gate-tunable material system. PMID:27505400

  18. Effects of calf weaning age and subsequent management systems on growth performance and carcass characteristics of beef steers.

    PubMed

    Moriel, P; Johnson, S E; Vendramini, J M B; McCann, M A; Gerrard, D E; Mercadante, V R G; Hersom, M J; Arthington, J D

    2014-08-01

    Brahman × British crossbred steers (n = 40 and 38 in yr 1 and 2, respectively) were used to evaluate the effects of calf management systems following early weaning (EW) on growth performance, muscle gene expression, and carcass characteristics. On the day of EW (d 0), steers were stratified by BW and age (95 ± 14 kg; 74 ± 14 d) and randomly assigned to a control treatment that was normally weaned (NW) on d 180 (n = 10 steers/yr) or to 1 of 3 EW treatments: 1) EW and limit fed a high-concentrate diet at 3.5% of BW (as-fed basis) in drylot until d 180 (EW180; n = 10 steers/yr), 2) EW and limit fed a high-concentrate diet at 3.5% of BW (as-fed basis) in drylot until d 90 and then grazed on bahiagrass pastures until d 180 (EW90; n = 10 steers/yr), or 3) EW and grazed on annual ryegrass pastures until d 60 (yr 1; n = 10 steers) or 90 (yr 2; n = 8 steers) and then on bahiagrass pastures until d 180 (EWRG). Early-weaned steers on ryegrass and bahiagrass pastures were supplemented with high-concentrate diet at 1.0% of BW (as-fed basis) until d 180. From d 180 to 270 (yr 1), all EW steers remained in their respective treatments, whereas NW steers were provided high-concentrate diet at 1.0% of BW (as-fed basis) on bahiagrass pastures. In yr 1, feedlot finishing period began on d 270. In yr 2, the study was terminated on d 180. In both years, EW180 steers were heaviest (P < 0.0001) on d 180. On d 180 of yr 1, EWRG steers were lightest (P < 0.0001) and EW90 steers were heavier (P = 0.05) than NW steers, whereas EW90, EWRG, and NW steers had similar BW on d 180 of yr 2 (P ≥ 0.14). On d 90, muscle PPARγ mRNA expression tended (P = 0.07) to be greater for EW180 steers and was greater (P = 0.008) for EW90 vs. EWRG steers but similar (P = 0.25) between EW180 and NW steers. On d 180, PPARγ mRNA was greater (P ≤ 0.06) for EW180 vs. NW, EW90, and EWRG steers. From d 274 to 302, EW180 steers had the least ADG (P ≤ 0.09), whereas EW90 steers had similar (P = 0.19) ADG

  19. 49 CFR 571.203 - Standard No. 203; Impact protection for the driver from the steering control system.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    .... 208 (49 CFR 571.208) by means of other than seat belt assemblies. It also does not apply to walk-in... control system is impacted by a body block in accordance with SAE Recommended Practice J944 JUN80 Steering... force developed on the chest of the body block transmitted to the steering control system shall...

  20. 49 CFR 571.203 - Standard No. 203; Impact protection for the driver from the steering control system.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    .... 208 (49 CFR 571.208) by means of other than seat belt assemblies. It also does not apply to walk-in... control system is impacted by a body block in accordance with SAE Recommended Practice J944 JUN80 Steering... force developed on the chest of the body block transmitted to the steering control system shall...

  1. Wheeled Vehicle Steering Systems. Military Curriculum Materials for Vocational and Technical Education.

    ERIC Educational Resources Information Center

    Army Ordnance Center and School, Aberdeen Proving Ground, MD.

    This course is one of several subcourses that make up the entire Army correspondence course on wheeled vehicle maintenance. The subcourse is designed to provide the student with information about the operation, malfunction diagnosis, maintenance, and repair of wheeled vehicle steering systems. It provides the basic theory, and also includes…

  2. V-TECS Guide for Auto Mechanics: Suspension Systems, Brakes and Steering.

    ERIC Educational Resources Information Center

    Moore, Charles G.; And Others

    The materials in this document are an extension of a catalog of occupational duties, tasks, and performance objectives relevant to maintaining automotive suspension systems, brakes, and steering mechanisms. This document provides the following for each occupational task within each duty: (1) a standard of performance; (2) the conditions under…

  3. 46 CFR 58.25-70 - Steering-gear control systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Steering-gear control systems. 58.25-70 Section 58.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY... gear must be operable from the pilothouse by mechanical, hydraulic, electrical, or other...

  4. 46 CFR 58.25-70 - Steering-gear control systems.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Steering-gear control systems. 58.25-70 Section 58.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY... gear must be operable from the pilothouse by mechanical, hydraulic, electrical, or other...

  5. 46 CFR 58.25-70 - Steering-gear control systems.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Steering-gear control systems. 58.25-70 Section 58.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MAIN AND AUXILIARY... gear must be operable from the pilothouse by mechanical, hydraulic, electrical, or other...

  6. Monogamy of quantum steering

    NASA Astrophysics Data System (ADS)

    Milne, Antony; Jennings, David; Jevtic, Sania; Rudolph, Terry; Wiseman, Howard

    The quantum steering ellipsoid formalism naturally extends the Bloch vector picture for qubits to provide a visualisation of two-qubit systems. If Alice and Bob share a correlated state then a local measurement by Bob steers Alice's qubit inside the Bloch sphere; given all possible measurements by Bob, the set of states to which Alice can be steered form her steering ellipsoid. We apply the formalism to a three-party scenario and find that steering ellipsoid volumes obey a simple monogamy relation. This gives us a novel derivation of the well-known CKW (Coffman-Kundu-Wootters) inequality for entanglement monogamy. The geometric perspective also identifies a new measure of quantum correlation, `obesity', and a set of `maximally obese' states that saturate the steering monogamy bound. These states are found to have extremal quantum correlation properties that are significant in the steering ellipsoid picture and for the study of two-qubit states in general.

  7. Simultaneous demultiplexing and steering of multiple orbital angular momentum modes

    PubMed Central

    Li, Shuhui; Wang, Jian

    2015-01-01

    We present a simple scheme to perform simultaneous demultiplexing and steering of multiple orbital angular momentum (OAM) modes using a single complex phase mask. By designing the phase mask, the propagation directions of demultiplexed beams can be arbitrarily steered. System experiments using orthogonal frequency-division multiplexing 32-ary quadrature amplitude modulation (OFDM-32QAM) signals over two OAM modes are carried out by using a two-mode complex phase mask. Moreover, demultiplexing of sixteen OAM modes and arbitrary demultiplexed beam steering are also demonstrated in the experiment. PMID:26503167

  8. Simultaneous demultiplexing and steering of multiple orbital angular momentum modes.

    PubMed

    Li, Shuhui; Wang, Jian

    2015-01-01

    We present a simple scheme to perform simultaneous demultiplexing and steering of multiple orbital angular momentum (OAM) modes using a single complex phase mask. By designing the phase mask, the propagation directions of demultiplexed beams can be arbitrarily steered. System experiments using orthogonal frequency-division multiplexing 32-ary quadrature amplitude modulation (OFDM-32QAM) signals over two OAM modes are carried out by using a two-mode complex phase mask. Moreover, demultiplexing of sixteen OAM modes and arbitrary demultiplexed beam steering are also demonstrated in the experiment. PMID:26503167

  9. Line-of-sight kinematics and corrections for fast-steering mirrors used in precision pointing and tracking systems

    NASA Astrophysics Data System (ADS)

    Hilkert, J. M.; Kanga, Gavin; Kinnear, K.

    2014-06-01

    Fast steering mirrors, or FSMs, have been used for several decades to enhance or augment the performance of electrooptical imaging and beam-steering systems in applications such as astronomy, laser communications and military targeting and surveillance systems. FSMs are high-precision, high-bandwidth electro-mechanical mechanisms used to deflect a mirror over a small angular displacement relative to the base it is mounted on which is typically a stabilized gimbal or other primary pointing device. Although the equations describing the line-of-sight kinematics derive entirely from the simple plane-mirror law of reflection, they are non-linear and axis-coupled and these effects increase as the FSM angular displacement increases. These inherent non-linearities and axis-coupling effects can contribute to pointing errors in certain modes of operation. The relevant kinematic equations presented in this paper can be used to assess the magnitude of the errors for a given application and make corrections as necessary.

  10. Control effects of steer-by-wire system for motorcycles on lane-keeping performance

    NASA Astrophysics Data System (ADS)

    Marumo, Yoshitaka; Katagiri, Nozomi

    2011-08-01

    This study discusses the control effects of the steer-by-wire (SBW) system for motorcycles on the lane-keeping performance by examining computer simulation with a rider-vehicle system which consists of a simplified vehicle model, a rider control model and the controller of the SBW system. The SBW system, which compensates the rolling angle deviation between the desired rolling angle intended by the rider and the actual rolling angle, improves the lane-keeping performance of the rider-vehicle system under the steering torque disturbance. The SBW system is, on the other hand, not effective in the lane-keeping performance under the lateral force disturbance. In addition, the lane-keeping assistance (LKA) system is applied to the SBW system and the cooperativeness of the SBW and the LKA systems is examined. The LKA system improves the lane-keeping performance of the SBW system under not only the steering torque disturbance but also the lateral force disturbance.

  11. Investigation of beam steering performances in rotation Risley-prism scanner.

    PubMed

    Li, Anhu; Sun, Wansong; Yi, Wanli; Zuo, Qiyou

    2016-06-13

    Rotation Risley-prism scanner appears to be the most promising solution to high-accuracy beam scanning and target tracking. In the paper, some important issues crucial to the function implementation are thoroughly investigated. First the forming law of scan blind zone relative to double-prism structural parameters is explored by a quantitative analysis method. Then the nonlinear relationship between the rotation speeds of double prisms and the change rate of beam deviation angle is presented, and the beam scan singularity is indicated as an essential factor that confines the beam scan region. Finally, the high-accuracy radial scan theory is verified to illustrate the important application owing to the high reduction ratio from the rotation angles of double prisms to the deviation angles of the emergent beam. The research not only reveals the inner mechanisms of the Risley-prism beam scanning in principle, but also provide a foundation for the nonlinear control of various beam scan modes. PMID:27410303

  12. Control of A Five-axle, Three-steering Coupled-vehicle System

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Hiroaki; Mori, Masato; Kawakami, Atsushi

    This paper presents a new type of coupled-vehicle system: a five-axle, three-steering coupled-vehicle system and its path following feedback control law. The coupled-vehicle system consists of two car-like mobile robots, two carriers and a steering system. One of the two car-like mobile robots is coupled by one of the two carriers via a revolute joint passively rotating and the other car-like mobile robot is also coupled by one remaining carrier via a passive revolute joint, and the two carriers are coupled via another passive revolute joint. The steering system is attached to one of the carriers and its steering axis is located at the same position of the rotating axis of the passive revolute joint coupling the two carriers. We first show that, by assuming virtual mechanical elements, it is possible to convert the kinematical equation of the coupled-vehicle system into three-chain, single-generator chained form in a coordinate system in which a path two times differentiable is an axis and a straight line perpendicular to the tangent of the path is another axis. Based on chained form, we secondly derive the path following feedback control law which enables the orientations of the two carriers relative to the tangent of the path to be controllable. By the feedback control law, it is possible to cause the two carriers to form a line-shaped composed carrier or a V-shaped composed carrier and to cause them to keep such shapes while performing a path following behavior, which means that the coupled-vehicle system is able to adapt the shape of the composed carrier to the shape of a transported object. The validity of the mechanical design of the coupled-vehicle system and its path following feedback control law has been verified experimentally.

  13. Vehicle having hydraulic and power steering systems using a single high pressure pump

    DOEpatents

    Bartley, Bradley E.; Blass, James R.; Gibson, Dennis H.

    2001-06-22

    A vehicle comprises a plurality of wheels attached to a vehicle housing. Also attached to the vehicle housing is a power steering system, including a fluid flow circuit, which is operably coupled to a number of the wheels. An internal combustion engine attached to the vehicle housing is connected to a hydraulically actuated system that includes a high pressure pump. An outlet of the high pressure pump is in fluid communication with the fluid flow circuit.

  14. Beam measurements on the H- source and Low Energy Beam Transport system for the Spallation Neutron Source

    SciTech Connect

    Thomae, R.; Gough, R.; Keller, R.; Leung, K.N.; Schenkel, T.; Aleksandrov, A.; Stockli, M.; Welton, R.

    2001-09-01

    The ion source and Low Energy Beam Transport section of the front-end systems presently being built by Berkeley Lab are required to provide 50 mA of H - beam current at 6% duty factor (1 ms pulses at 60 Hz) with a normalized rms emittance of less than 0.20 p-mm-mrad. Experimental results, including emittance, chopping, and steering measurements, on the performance of the ion source and LEBT system operated at the demanded beam parameters will be discussed.

  15. Modeling of Steer-by-Wire System Used in New Braking Handwheel Concept

    NASA Astrophysics Data System (ADS)

    Messaoudène, K.; Oufroukh, N. Ait; Mammar, S.

    2008-06-01

    The handwheel is one of the primary control mechanisms of automobile thus interaction between the handwheel and the driver is critical to safety. The driver applies forces that direct the vehicle while the handwheel communicates feedback information to the driver of the forces experience by the car within its environment. The handwheel also provides a predictable mechanical feel to the driver to allow smooth and safe control. Many researchers tried to reproduce this feeling by creating steer-by-wire systems. This paper explores this new concept of handwheel and it describes the modeling steps of the components including the restitution mechanism for force feedback and its various links with the vehicle lateral dynamics and the pneumatic contacts. The aim is to explore the possibility to combine a braking device within the steer-by-wire system in order to provide a more suitable and ergonomic device to the driver.

  16. System design and algorithmic development for computational steering in distributed environments

    SciTech Connect

    Wu, Qishi; Zhu, Mengxia; Gu, Yi; Rao, Nageswara S

    2010-03-01

    Supporting visualization pipelines over wide-area networks is critical to enabling large-scale scientific applications that require visual feedback to interactively steer online computations. We propose a remote computational steering system that employs analytical models to estimate the cost of computing and communication components and optimizes the overall system performance in distributed environments with heterogeneous resources. We formulate and categorize the visualization pipeline configuration problems for maximum frame rate into three classes according to the constraints on node reuse or resource sharing, namely no, contiguous, and arbitrary reuse. We prove all three problems to be NP-complete and present heuristic approaches based on a dynamic programming strategy. The superior performance of the proposed solution is demonstrated with extensive simulation results in comparison with existing algorithms and is further evidenced by experimental results collected on a prototype implementation deployed over the Internet.

  17. ADDJUST - An automated system for steering Centaur launch vehicles in measured winds

    NASA Technical Reports Server (NTRS)

    Swanson, D. C.

    1977-01-01

    ADDJUST (Automatic Determination and Dissemination of Just-Updated Steering Terms) is an automated computer and communication system designed to provide Atlas/Centaur and Titan/Centaur launch vehicles with booster-phase steering data on launch day. Wind soundings are first obtained, from which a smoothed wind velocity vs altitude relationship is established. Design for conditions at the end of the boost phase with initial pitch and yaw maneuvers, followed by zero total angle of attack through the filtered wind establishes the required vehicle attitude as a function of altitude. Polynomial coefficients for pitch and yaw attitude vs altitude are determined and are transmitted for validation and loading into the Centaur airborne computer. The system has enabled 14 consecutive launches without a flight wind delay.

  18. Method and system for controlling the position of a beam of light

    DOEpatents

    Steinkraus, Jr., Robert F.; Johnson, Gary W.; Ruggiero, Anthony J.

    2011-08-09

    An method and system for laser beam tracking and pointing is based on a conventional position sensing detector (PSD) or quadrant cell but with the use of amplitude-modulated light. A combination of logarithmic automatic gain control, filtering, and synchronous detection offers high angular precision with exceptional dynamic range and sensitivity, while maintaining wide bandwidth. Use of modulated light enables the tracking of multiple beams simultaneously through the use of different modulation frequencies. It also makes the system resistant to interfering light sources such as ambient light. Beam pointing is accomplished by feeding back errors in the measured beam position to a beam steering element, such as a steering mirror. Closed-loop tracking performance is superior to existing methods, especially under conditions of atmospheric scintillation.

  19. Rolling Beam Umbilical System

    NASA Technical Reports Server (NTRS)

    Tatem, B. C., Jr.

    1983-01-01

    The decision to make the Centaur Vehicle a Space Transportation System (STS) payload meant that new ground support equipment provisions at Launch Pads Pads 39A and 39B were required. These new equipment provisions were needed to service the Centaur vehicle while it was installed in the Orbiter's payload bay prior to launch. This paper describes the design of a new rolling beam umbilical syste (RBUS) being added to the pad fixed service structure (FSS) in order to provide the primary functions of liquid hydrogen (LH2) fill, drain, and vent. The carrier plate itself is a Government-furnished equipment item and of necessity became a T-O disconnect. This permits quick offloading in the event of an abort prior to lift-off. In addition to the rolling beam structure, mechanisms, and fluid lines, it was necessary to design and build a carrier plate simulator to support early development testing of the mast at the Launch Equipment Test Facility at Kennedy Space Center. The RBUS is designed to be compatible with the rotating service structure (RSS) to the extent that the umbilical may be deployed with the RSS mated with the vehicle. It is also designed to clear the RSS as the RSS rotates back out of the way. Accessibility to the Orbiter aft compartment via the 50-1 door had to be maintained.

  20. Fiber optic sensor for angular position measurement: application for an electrical power-assisted steering system

    NASA Astrophysics Data System (ADS)

    Javahiraly, Nicolas; Chakari, Ayoub

    2013-05-01

    To achieve a very effective automotive power steering system, we need two important data, the angular position of the wheel and the torque applied on the shaft by the driver of the car. We present a new accurate optical fiber angular position sensor connected to an automotive power steering column. In this new design, the sensor allows the measurement of the angular position of a car steering wheel over a large and adjustable range (± several turns of the wheel). The wheel rotation induces micro-bending in the transducer part of the optical fiber sensing system. This system operates as an amplitude modulation sensor based on mode coupling in the transducing fiber in the case when all the modes are equally excited. We study the sensor response both theoretically and experimentally with a multimode step index optical fiber [rf (fiber radius) = 300 μm rc (core radius) = 50 μm nc (core index) = 1,457; N.A. = 0, 22 and the wavelength is 632,8 nm at the ambient Temperature (20°C)]. We show that the sensitivity can be controlled as a function of the sensor's length. We compare modeling and experimental validation and we conclude with a perspective on what could soon be an industrial sensor.

  1. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XXIII, I--MAINTAINING THE FUEL SYSTEM, PART II--CATERPILLAR DIESEL ENGINE, II--UNDERSTANDING STEERING SYSTEMS.

    ERIC Educational Resources Information Center

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE FUEL INJECTION SYSTEM AND THE STEERING SYSTEM OF DIESEL POWERED VEHICLES. TOPICS ARE FUEL INJECTION SECTION, AND DESCRIPTION OF THE STEERING SYSTEM. THE MODULE CONSISTS OF A SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING…

  2. Current Control in ITER Steady State Plasmas With Neutral Beam Steering

    SciTech Connect

    R.V. Budny

    2009-09-10

    Predictions of quasi steady state DT plasmas in ITER are generated using the PTRANSP code. The plasma temperatures, densities, boundary shape, and total current (9 - 10 MA) anticipated for ITER steady state plasmas are specified. Current drive by negative ion neutral beam injection, lower-hybrid, and electron cyclotron resonance are calculated. Four modes of operation with different combinations of current drive are studied. For each mode, scans with the NNBI aimed at differing heights in the plasma are performed to study effects of current control on the q profile. The timeevolution of the currents and q are calculated to evaluate long duration transients. Quasi steady state, strongly reversed q profiles are predicted for some beam injection angles if the current drive and bootstrap currents are sufficiently large.

  3. Particle beam injection system

    DOEpatents

    Jassby, Daniel L.; Kulsrud, Russell M.

    1977-01-01

    This invention provides a poloidal divertor for stacking counterstreaming ion beams to provide high intensity colliding beams. To this end, method and apparatus are provided that inject high energy, high velocity, ordered, atomic deuterium and tritium beams into a lower energy, toroidal, thermal equilibrium, neutral, target plasma column that is magnetically confined along an endless magnetic axis in a strong restoring force magnetic field having helical field lines to produce counterstreaming deuteron and triton beams that are received bent, stacked and transported along the endless axis, while a poloidal divertor removes thermal ions and electrons all along the axis to increase the density of the counterstreaming ion beams and the reaction products resulting therefrom. By balancing the stacking and removal, colliding, strong focused particle beams, reaction products and reactions are produced that convert one form of energy into another form of energy.

  4. Retro-modulators and fast beam steering for free-space optical communications

    NASA Astrophysics Data System (ADS)

    Chan, Trevor Keith

    Free-space optical (FSO) communications is a means of secure, high bandwidth communication through the use of a modulated laser beam in free-space as the information medium. The chaotic nature of the atmosphere and the motion of the communication nodes make laser alignment a crucial concern. The employment of retro-reflecting modulators makes the bidirectional quality of a communication link into a one sided alignment problem. While there are existing retro-reflecting modulators, their trade-offs create a lack of abilities (such as aperture size, angular range, high modulation speeds, economic viability) which do not fulfill the requirements for certain applications. Also, the beam must be directed towards the intended receiver. Form mobile or scintillated communication links, beam direction must be adaptable in real time. Once again, this area suffers from trade-offs where beamsteering speed is often limited. Research used to mitigate the trade-offs and adapt the devices into viable options for a wider range of applications is explored in this dissertation. Two forms of retro-modulators were explored; a MEMS deformable mirror retro-modulator and a solid silicon retro-modulator that modulated the light by frustrated total internal reflection (FTIR). The MEMS version offered a high speed, scalable, wavelength/angle insensitive retro-modulator which can be massed produced at low cost, while the solid retro-modulator offered a large field of view with low cost as well. Both modulator's design, simulated performances, fabrication and experimental characterization are described in this dissertation. An ultra-fast beamscanner was also designed using 2-dimensional dispersion. By using wavelength switching for directional control, a beamscanner was developed that could switch light faster than pre-existing beamscanners while the beams characteristics (most importantly its aperture) could be freely adjusted by the independent optics. This beamscanner was preceded by our

  5. Carcass characteristics, the calpain proteinase system, and aged tenderness of Angus and Brahman crossbred steers.

    PubMed

    Pringle, T D; Williams, S E; Lamb, B S; Johnson, D D; West, R L

    1997-11-01

    We used 69 steers of varying percentage Brahman (B) breeding (0% B, n = 11; 25% B, n = 13; 37% B, n = 10; 50% B, n = 12; 75% B, n = 12; 100% B, n = 11) to study the relationship between carcass traits, the calpain proteinase system, and aged meat tenderness in intermediate B crosses. Calpains and calpastatin activities were determined on fresh longissimus muscle samples using anion-exchange chromatography. The USDA yield and quality grade data (24 h) were collected for each carcass. Longissimus steaks were removed and aged for 5 or 14 d for determination of shear force and 5 d for sensory panel evaluation. Even though some yield grade factors were affected by the percentage of B breeding, USDA yield grades did not differ (P > .15) between breed types. Marbling score and USDA quality grade decreased linearly (P < .01) with increasing percentage of B breeding. Shear force after 5 and 14 d of aging was higher (P < .05) in the 100% B steers than in all other breed types, which were not significantly different. Sensory panel tenderness and connective tissue scores decreased linearly (P < .05) with increasing B breeding. A quadratic effect was also noted for tenderness and connective tissue scores; 37% B steers received the highest scores. A similar response was found in mu-calpain activities; the 37% B steers had the highest activities. Conversely, calpastatin activity increased linearly (P < .01) with increasing percentage B breeding. These data show strong linear relationships between calpastatin activity (positive), marbling score (negative), and percentage B breeding, suggesting a possible combined effect of these traits on aged tenderness of intermediate Brahman crosses. PMID:9374310

  6. An improved lateral control wheel steering law for the Transport Systems Research Vehicle (TSRV)

    NASA Technical Reports Server (NTRS)

    Ragsdale, W. A.

    1992-01-01

    A lateral control wheel steering law with improved performance was developed for the Transport Systems Research Vehicle (TSRV) simulation and used in the Microwave Landing System research project. The control law converted rotational hand controller inputs into roll rate commands, manipulated ailerons, spoilers, and the rudder to achieve the desired roll rates. The system included automatic turn coordination, track angle hold, and autopilot/autoland modes. The resulting control law produced faster roll rates (15 degrees/sec), quicker response to command reversals, and safer bank angle limits, while using a more concise program code.

  7. Integrated Computational System for Aerodynamic Steering and Visualization

    NASA Technical Reports Server (NTRS)

    Hesselink, Lambertus

    1999-01-01

    In February of 1994, an effort from the Fluid Dynamics and Information Sciences Divisions at NASA Ames Research Center with McDonnel Douglas Aerospace Company and Stanford University was initiated to develop, demonstrate, validate and disseminate automated software for numerical aerodynamic simulation. The goal of the initiative was to develop a tri-discipline approach encompassing CFD, Intelligent Systems, and Automated Flow Feature Recognition to improve the utility of CFD in the design cycle. This approach would then be represented through an intelligent computational system which could accept an engineer's definition of a problem and construct an optimal and reliable CFD solution. Stanford University's role focused on developing technologies that advance visualization capabilities for analysis of CFD data, extract specific flow features useful for the design process, and compare CFD data with experimental data. During the years 1995-1997, Stanford University focused on developing techniques in the area of tensor visualization and flow feature extraction. Software libraries were created enabling feature extraction and exploration of tensor fields. As a proof of concept, a prototype system called the Integrated Computational System (ICS) was developed to demonstrate CFD design cycle. The current research effort focuses on finding a quantitative comparison of general vector fields based on topological features. Since the method relies on topological information, grid matching and vector alignment is not needed in the comparison. This is often a problem with many data comparison techniques. In addition, since only topology based information is stored and compared for each field, there is a significant compression of information that enables large databases to be quickly searched. This report will (1) briefly review the technologies developed during 1995-1997 (2) describe current technologies in the area of comparison techniques, (4) describe the theory of our new

  8. Laser beam alignment system

    DOEpatents

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

    1984-01-01

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

  9. Mechanical 144 GHz beam steering with all-metallic epsilon-near-zero lens antenna

    NASA Astrophysics Data System (ADS)

    Pacheco-Peña, V.; Torres, V.; Orazbayev, B.; Beruete, M.; Navarro-Cía, M.; Sorolla, M.; Engheta, N.

    2014-12-01

    An all-metallic steerable beam antenna composed of an ɛ-near-zero (ENZ) metamaterial lens is experimentally demonstrated at 144 GHz (λ0 = 2.083 mm). The ENZ lens is realized by an array of narrow hollow rectangular waveguides working just near and above the cut-off of the TE10 mode. The lens focal arc on the xz-plane is initially estimated analytically as well as numerically and compared with experimental results demonstrating good agreement. Next, a flange-ended WR-6.5 waveguide is placed along the lens focal arc to evaluate the ENZ-lens antenna steerability. A gain scan loss below 3 dB is achieved for angles up to ±15°.

  10. Consistent Steering System using SCTP for Bluetooth Scatternet Sensor Network

    NASA Astrophysics Data System (ADS)

    Dhaya, R.; Sadasivam, V.; Kanthavel, R.

    2012-12-01

    Wireless communication is the best way to convey information from source to destination with flexibility and mobility and Bluetooth is the wireless technology suitable for short distance. On the other hand a wireless sensor network (WSN) consists of spatially distributed autonomous sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants. Using Bluetooth piconet wireless technique in sensor nodes creates limitation in network depth and placement. The introduction of Scatternet solves the network restrictions with lack of reliability in data transmission. When the depth of the network increases, it results in more difficulties in routing. No authors so far focused on the reliability factors of Scatternet sensor network's routing. This paper illustrates the proposed system architecture and routing mechanism to increase the reliability. The another objective is to use reliable transport protocol that uses the multi-homing concept and supports multiple streams to prevent head-of-line blocking. The results show that the Scatternet sensor network has lower packet loss even in the congestive environment than the existing system suitable for all surveillance applications.