| Liquid Crystal Based Optical Phased Array for Steering Lasers |
Oct-2009 |
192 pages |
| Authors:
Lei Shi; Philip Bos; KENT STATE UNIV OH
|
 | Beam steering technologies are attracting more and more research interests and attention because of the benefits of fast tuning, light weight, and synergy with adaptive optics. The liquid crystal OPA technology has been considered for small angle beam steering because of the small pitch, low driving voltages, large birefringence, flexibility, and electrical control. However, the large area resets of the phase profile caused by the fringe fields degrade the achievable ... |
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| Structural Mechanics for Adaptive Optics |
26-Jul-2009 |
6 pages |
| Authors:
Daniel J Inman; VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG
|
| The research performed under this grant developed the structural mechanics of an adaptive optic system consisting of a membrane reflective surface stretched over a pressurized cavity. The work presented here starts under the assumption that the quality of optical system is described by Zernike Polynomials and proceeded by coupling the Zernike Polynomials to the membrane dynamics and provide several methods to control the membrane surface and hence the optical quality. ... |
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| The Aggregate Behavior of Branch Points I - The Creation and Evolution of Branch Points (Postprint) |
19-Jun-2009 |
18 pages |
| Authors:
Darryl J Sanchez; Denis W Oesch; AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE
|
| It has long been known that branch points cause degradation in adaptive optic performance. Here, we begin a study on the aggregate nature of branch points, specifically beginning the process to relate branch points measured in the pupil to the upstream turbulence that created them. As such, we study not only the wave as measured in the telescope's pupil, but also the wave in the intervening region between the turbulence ... |
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| A New Sodium Guidestar Adaptive Optics System for the Starfire Optical Range 3.5 m Telescope (Postprint) |
18-May-2009 |
6 pages |
| Authors:
ROBERT JOHNSON; Dennis Montera; Timothy Schneeberger; James Spinhirne; AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE
|
| A new adaptive optics is being installed on the Starfire 3.5 m telescope. Its uses the existing 50 watt pump to create a sodium guidestar. Transmission to the wavefront sensor is improved from 0.16 to 0.75. |
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| Volume Control Manifold for Membrane Adaptive Optics |
15-May-2009 |
8 pages |
| Authors:
Dan K Marker; Jim Rotge; Steve Hanes; BOEING LASER TECHNICAL SERVICES (LTS) COLORADO SPRINGS CO
|
| An innovative adaptive optic concept is discussed that provides a dramatically improved dynamic bandwidth over existing approaches. This innovation is associated with membrane adaptive optics such as silicon nitride and polymer based films. This concept utilizes a volume control manifold that is co-located with the electrostatic actuators to dramatically improve total actuator force which in turn improves dynamic bandwidth and stroke. Presented is the result of a laboratory experiment showing ... |
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| Fine Surface Control of Flexible Space Mirrors Using Adaptive Optics and Robust Control |
Mar-2009 |
60 pages |
| Authors:
Daniel C Burtz; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Future space telescopes will contain lightweight, flexible, segmented mirrors. Traditional control approaches for mirror alignment and shape control may be inadequate due to flexibilities and low natural frequencies. Using adaptive optics for space telescopes presents a possible solution. This research proposes innovative H(infinity) robust control techniques for these types of systems. An H(infinity) controller is synthesized for a complex analytical model with 997 inputs, 936 outputs, and 332 states. To ... |
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| Misregistration in Adaptive Optics Systems |
Mar-2009 |
79 pages |
| Authors:
Nathan Engstrom; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| An adaptive optics (AO) system is most effective when there is a known alignment between the wave front sensor (WFS)and the deformable mirror (DM). Misregistration is the term for the unknown alignment between the WFS and DM. Misregistration degrades system performance and can make the system unstable. An AO system uses a reconstruction matrix to transform WFS measurements into DM commands. A standard AO system uses a model reconstruction matrix ... |
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| Adaptive Control Of Woofer-Tweeter Adaptive Optics |
Mar-2009 |
82 pages |
| Authors:
Jimmie J Perez; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Adaptive optics applies advanced sensing and control to improve the ability of optical systems to collect images through a turbulent atmosphere. The results of this research effort demonstrate that the combination of two recent approaches improves the performance of adaptive optics in directed energy and laser communication scenarios. The first approach is adaptive control, which offers improved performance over fixed-gain controllers in the presence of rapidly changing turbulence. The second ... |
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| Measuring Tilt and Focus for Sodium Beacon Adaptive Optics on the Starfile 3.5 Meter Telescope -- Conference Proceedings (Preprint) |
01-Sep-2008 |
10 pages |
| Authors:
ROBERT JOHNSON; AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE
|
| Adaptive optics systems can measure high-order aberrations using an artificial laser beacon without the need for a relatively bright object near the object being imaged. Unfortunately, tilt and focus measurements are difficult to obtain from a laser beacon. One solution is to use light from the object being imaged to measure tilt and focus. Through analysis, I estimate the performance of using a Shack-Hartmann wavefront sensor with 2 by 2 ... |
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| Closed-Loop Adaptive Optics Control in Strong Atmospheric Turbulence |
01-Sep-2008 |
151 pages |
| Authors:
Todd M Venema; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| A self-referencing interferometer based closed-loop adaptive optics controller is developed which is designed to operate effectively under strong turbulence conditions. The aberrated optical field is modeled stochastically and then estimates of the state of the system are developed using a steady-state, fixed-gain Kalman filter. The phase of the optical field is considered the state of the system which is wrapped in a limited range of (-pi;pi]. This phase is unwrapped ... |
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| Consortium for Adaptive Optics and Image Post-Processing |
12-Jun-2008 |
18 pages |
| Authors:
Joseph Janni; Stuart Jefferies; MAUI ECONOMIC DEVELOPMENT BOARD KIHEI HI
|
| This was an unusual grant in that it s purpose was to improve ongoing basic research and make it more efficient and effective, rather than to actually sponsor research itself. We are pleased to report that this was being achieved. Activity under this grant is resulting in more effective adaptive optics and image post-processing basic research for the Air Force. In particular, it is enabling cross-organizational communication to a larger ... |
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| Image Reconstruction, Wave Front Sensing, and Adaptive Optics in Extreme Atmospheric Seeing Conditions |
02-Jun-2008 |
13 pages |
| Authors:
Michael C Roggemann; Timothy J Schulz; MICHIGAN TECHNOLOGICAL UNIV HOUGHTON
|
| On June 1, 2005 AFOSR awarded a grant to Michigan Technological University to investigate image reconstruction, wave front sensing, and adaptive optics in extreme imaging conditions. This is the final report for this program. The overall goal was to understand imaging under conditions where seeing is exceedingly poor, such as for space surveillance of objects at very low elevation angles, and during daytime hours. In these situations, scintillation and small ... |
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| Optical Phase Unwrapping in the Presence of Branch Points |
12-May-2008 |
15 pages |
| Authors:
Todd M Venema; Jason D Schmidt; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| Strong turbulence causes phase discontinuities known as branch points in an optical field. These discontinuities complicate the phase unwrapping necessary to apply phase corrections onto a deformable mirror in an adaptive optics (AO) system. This paper proposes a non-optimal but effective and implementable phase unwrapping method for optical fields containing branch points. This method first applies a least-squares (LS) unwrapper to the field which isolates and unwraps the LS component ... |
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| Analysis of Non-Uniform Gain for Control of a Deformable Mirror in an Adaptive-Optics System |
MAR 2008 |
131 pages |
| Authors:
Kevin P. Vitayaudom; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The objective of this research was to develop and experimentally verify the use of spatially varying gain maps on the servo-loop controller of a deformable mirror for improvements in the performance of an adaptive optics system and the mitigation of instabilities that can occur over edge actuators of a deformable mirror. The edge subapertures of a Shack-Hartmann wavefront sensor have lower signal-to-noise ratios and are more susceptible to measurement errors ... |
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| Limitations of Segmented Wavefront Control Devices in Emulating Optical Turbulence |
MAR 2008 |
111 pages |
| Authors:
Michael D. Plourde; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| Using a device to act as a surrogate for atmospheric turbulence in a laboratory is necessary to build and test optical systems for imaging, lidar, laser weapons, and laser communications. Liquid-crystal spatial light modulators (LC SLMs) and segmented micro-electro-mechanical-system (MEMS) deformable mirrors (DMs) are commonly used devices for altering wavefronts in order to simulate a portion of atmospheric turbulence. The best location of these devices was theoretically analyzed to obtain ... |
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| Wavefront Control for Space Telescope Applications Using Adaptive Optics |
01 DEC 2007 |
109 pages |
| Authors:
Matthew R. Allen; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Future long dwell high resolution imagery satellites and space telescopes will require very large flexible primary mirrors. These large mirrors face many challenges including optical surface imperfections, structural vibrations, and jitter. A flexible mirror can overcome some of these challenges by applying adaptive optics techniques to correct mirror deformations and aberrations to produce image quality data. This paper examines and develops control techniques to control a deformable mirror subjected to ... |
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| Adaptive Optics Performance Model for Optical Interferometry |
10 JUL 2007 |
11 pages |
| Authors:
D. Mozurkewich; S. R. Restaino; J. T. Armstrong; G. C. Gilbreath; NAVAL RESEARCH LAB WASHINGTON DC OPTICAL SCIENCES DIV
|
| The optical interferometry community has discussed the possibility of using adaptive optics (AO) on apertures much larger than the atmospheric coherence length in order to increase the sensitivity of an interferometer, although few quantitative models have been investigated. The aim of this paper is to develop an analytic model of an AO-equipped interferometer and to use it to quantify, in relative terms, the gains that may be achieved over an ... |
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| Extragalactic Optical-Radio Link Research at USNO |
2007 |
7 pages |
| Authors:
N. Zacharias; M. I. Zacharias; D. Boboltz; A. Fey; R. Gaume; G. S. Hennessy; K. J. Johnston; R. Ojha; NAVAL OBSERVATORY WASHINGTON DC
|
| Over 500 counterparts of International Celestial Reference Frame (ICRF) sources were observed during 24 deep CCD observing runs as part of the USNO CCD Astrograph Catalog (UCAC) project, providing a direct link to Tycho-2 stars. For some sources a positional accuracy of 10 mas is achieved. A sample of 12 extragalactic ICRF sources are being observed at the Naval Observatory Flagstaff Station's (NOFS) 1.55-meter telescope over several years to monitor ... |
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| Closed-Loop Control Techniques for an Adaptive-Optical System with an Interferometric Wavefront Sensor (Postprint) |
01 SEP 2006 |
11 pages |
| Authors:
Laura M. Klein; Troy A. Rhoadarmer; AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE
|
| The self-referencing interferometer (SRI) wavefront sensor (WRS) is being developed for applications requiring laser propagation in strong scintillation. Because it directly measures the optical field of the wavefront, the SRI WFS is less effected by scintillation than conventional WFSs. This feature also means the phrase determined from the WRS measurements is limited to the range-pie to pie, due to the use of the arctangent function. If a segmented wavefront corrector ... |
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| How Important is Oblique Vision in Aviation? |
15 AUG 2006 |
24 pages |
| Authors:
Cheng-Jong Chang; TRI-SERVICE GENERAL HOSPITAL TAIPEI (TAIWAN)
|
| (A) We propose a basic system layout that combines with the microdisplay for contrast sensitivity function measurement. The optical components need to be modified to eliminate the aberrations. (B) We made the power and control electronics for this system that increase the capabilities to build the specific deformable pattern by our self. (C) We measured the interferences patterns for the deformable mirror and build the influences matrix (D) We did ... |
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| Intensity Redistribution for Multiconjugate Adaptive Optics (postprint) |
10 AUG 2006 |
11 pages |
| Authors:
Troy Rhoadarmer; Jr. Beckner Charles C.; Laura M. Klein; AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE
|
| Multi-Conjugate Adaptive-Optical (MCAO) systems have been proposed as a means of compensating both intensity and phase aberrations in a beam propagating through strong-scintillation environments. Progress made on implementing a MCAO system at the Starfire Optical Range (SOR), Air Force Research Laboratory, Kirtland AFB, is discussed. As a preliminary step toward controlling a two Deformable Mirror (DM) system, the first-stage intensity redistribution experiment (FIRE) examines one aspect of an MCAO system-control ... |
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| Fabrication, Testing, Coating and Alignment of Fast Segmented Optics |
25 MAY 2006 |
24 pages |
| Authors:
Hubert Martin; Roger Angel; James Burge; Joseph Talghader; STEWARD OBSERVATORY TUCSON AZ
|
| The report presents the results of the MRI addressing four of the most critical technologies needed to produce large-aperture, lightweight, high-power HEL systems. They are: polishing large off-axis segments of fast primary mirrors; testing large segments in an off-axis geometry; alignment of multiple segments of a large mirror; and coatings that reflect high-intensity light without distorting the substrate. The program made substantial progress in all areas. Some of the most ... |
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| Naval Prototype Optical Interferometer (NPOI) Upgrade with Lightweight Telescopes and Adaptive Optics: A Status Update |
Apr-2006 |
9 pages |
| Authors:
Sergio R Restaino; Jonathan R Andrews; Tom Armstrong; Christopher C Wilcox; Robert Romeo; Robert Martin; NAVAL RESEARCH LAB KIRTLAND AFB NM REMOTE SENSING DIV
|
| The portability of meter-class telescopes has been limited by the weight of the mirror, tube assembly, and the mount required to provide pointing and tracking. The novel lightweight carbon fiber-reinforced polymer telescopes being developed for array population at the Naval Prototype Optical Interferometer are orders of magnitude lighter than traditional telescopes. When combined with a lightweight carbon fiber mount, these telescopes will be easily transportable from one telescope station to ... |
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| Multi-Dimensional Wave Front Sensing Algorithms for Embedded Tracking and Adaptive Optics Applications |
MAR 2006 |
157 pages |
| Authors:
Christopher C. Wood; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| Current tracking and adaptive optics techniques cannot compensate for fast-moving extended objects, which is important for ground-based telescopes providing space situational awareness. To fill this need, a vector-projection maximum-likelihood wave-front sensing algorithm development and testing follows for this application. A derivation and simplification of the Cramer-Rao Lower Bound for wavefront sensing using a laser guide star bounds the performance of these systems and guides implementation of a vastly optimized maximum-likelihood ... |
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| Optical Beam Control Using Adaptive Optics |
DEC 2005 |
93 pages |
| Authors:
Lisa McLaughlin; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Adaptive optics is a new and growing research area aimed at creating high-quality imagery by correcting aberrations in optical systems caused by turbulence in the earth s atmosphere. This paper concentrates on the basics of physical optics leading into the design of an adaptive optics test bed to study the correction of aberrations using optical beam control. Adaptive optics requires the use of sophisticated optical equipment such as deformable mirrors ... |
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| Experimental Results of a MEMS-Based Adaptive Optics System |
DEC 2005 |
5 pages |
| Authors:
Sergio R. Restaino; G. C. Gilbreath; Don M. Payne; Jonathan R. Andrews; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| Adaptive optics techniques have been demonstrated in both laboratory and field tests, with a great level of scientific satisfaction, especially in astronomical and surveillance communities. Such successes have sparked the interest for these techniques in other fields, like biomedical imaging and industrial applications. However, to decrease complexity and costs, both very important issues for applications other than astronomical and surveillance, new technologies have to be brought to fruition. MEMS are ... |
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| Membrane Adaptive Optics |
01 AUG 2005 |
10 pages |
| Authors:
Dan Marker; James Wilkes; Eric Riggiero; Dab Inman; AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE
|
| An innovative adaptive optic is discussed that provides a range of capabilities unavailable with either existing, or newly reported, research devices. It is believed that this device will be inexpensive and uncomplicated to construct and operate, with a large correction range that should dramatically relax the static and dynamic structural tolerances of a telescope. As the areal density of a telescope primary is reduced, the optimal optical figure and the ... |
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| Evaluation of Phase-Shifting Techniques for a Self-Referencing Interferometer Wavefront Sensor (Postprint) |
29 JUL 2005 |
14 pages |
| Authors:
Melissa S. Corley; Troy A. Rhoadarmer; AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE
|
| The Air Force Research Laboratory is developing a Self-Referencing Interferometer (SRI) wavefront sensor (WFS) for applications requiring laser propagation in strong scintillation. This paper compares several phase-shifting techniques that can be used to capture interference patterns and examines their effects on SRI WFS performance. These techniques included temporal, spatial, spatial-temporal phase shifting. Temporal phase shifting allows for straightforward setup, alignment, and calibration, though its performance is degraded by changes in ... |
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| Performance Measurements of a Self-Referencing Interferometer Wavefront Sensor with Optical Amplification--Briefing Charts (Preprint) |
29 JUL 2005 |
18 pages |
| Authors:
Laura Klein; Troy A. Rhoadarmer; AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE
|
| The Self-referencing Interferometer Wavefront Sensor (SRI WFS) has been shown to outperform conventional wavefront sensors in strong scintillation environments. Recently, the Starfire Optical Range has developed a prototype SRI to evaluate its performance. This paper discusses the purposes of optically amplifying the reference beam. Specifically, it addresses regions of operation where gain improves signal-to-noise ratio (SNR) values, and thus the SRI WFS performance. Conditions are also addresses when Amplified Spontaneous ... |
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| DARPA Bio-Optic Synthetic Systems Programs: A Novel Lens System Featuring a Highly Dynamic Focal Length |
11 JUN 2004 |
37 pages |
| Authors:
Steven A. Snow; Udo C. Pernisz; Kai Su; Fumito Nishida; Timothy M. Lauer; DOW CORNING CORP MIDLAND MI
|
| The major goal of the project was to develop an adaptive optical system featuring a radical, dynamic and reversible change in focal length using polydimethylsiloxane (silicone) science and technology. The assertion that silicone-functional mesogens (liquid crystals), where the mesogen displayed an intrinsically high birefringence, would behave similarly and yield the necessary nematic liquid crystalline mesophase in an appropriate temperature range, was demonstrated to be a robust hypothesis. The silicone portion ... |
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| Adaptive Optics Performance Model for Optical Interferometry |
2004 |
8 pages |
| Authors:
D. Mozurkewich; S. R. Restaino; G. C. Gilbreath; SEABROOK ENGINEERING SEABROOK MD
|
| We argue that adding large apertures with adaptive optics to an optical interferometer improves the performance of the interferometer in two ways: it improves the signal to noise of bright, low-visibility fringes and it also improves the sensitivity of the interferometer. A simple model is presented to support this conclusion. |
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| A Massively Parallel Simulation Code for AEOS and Astronomical Adaptive Optics |
2004 |
10 pages |
| Authors:
Brent Ellerbroek; ASSOCIATION OF UNIVERSITIES FOR RESEARCH IN ASTRONOMY-GEMINI HILO HI GEMINI OBSERVATORY
|
| This is the second and final status report for a project to port an existing parallel adaptive optics (AO) simulation code to the Huinalu cluster at the Maui High Performance Computing Center, and to upgrade the simulation to provide an improved modeling capability for both the AEOS AO system and the astronomical AO systems proposed for future extremely large telescopes (ELTs). The functional elements of the simulation include the basic ... |
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| Developing a Portable NRL Fast Frame Rate Seeing Monitor |
2004 |
11 pages |
| Authors:
Bun Oh; James L. Murphy; Jeffrey T. Baker; G. C. Gilbreath; Robert B. Hindsley; David Mozurkewich; Sergio R. Restaino; Susan L. Fortenberry; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| We describe the development of a portable NRL seeing monitor which consists of a 12 inch Meade f/10 telescope with a Dalsa Cad6 260x260 camera having 10 micron pixels. This seeing monitor is capable of up to 700 frames per second. We have three different techniques to measure Fried's r0 parameter: full aperture, two-hole mask, and two-hole mask with in-line intensifier. For the observations done at the Anderson Mesa, Arizona ... |
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| Compact Adaptive Optics Systems 2 (CAOS-II) |
21 SEP 2003 |
17 pages |
| Authors:
Alan H. Greenaway; HERIOT-WATT UNIV EDINBURGH (UNITED KINGDOM) DEPT OF PHYSICS
|
| This report results from a contract tasking Heriot-Watt University as follows: The contractor will (1) determine the conditions for construction of a null sensor using the phase-diversity principle and implemented using a diffractive optical element (DOE) and a single detector plane; (2) investigate and, if possible, quantify necessary conditions for the use of a null sensor based on phase-diversity and the use of DOEs; (3) investigate whether a null sensor ... |
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| Three-Dimensional Structure of Turbulent Scalar Fields With Applications in Aerooptics |
15 MAY 2003 |
17 pages |
| Authors:
Paul E. Dimotakis; Christopher Martin; CALIFORNIA INST OF TECH PASADENA GRADUATE AERONAUTICAL LABS
|
| This is the final report for AFOSR Grant F49620-OO-l-0036, which ended 31 Jan 2003. This program aimed to develop an interferometric technique for mitigating the effects of turbulence on visible-light imaging, complementary to techniques such as Adaptive Optics (AO) or speckle imaging. This technique employs a rotation shearing interferometer and high-speed, low-noise digital imaging system. Where an AO system would employ a complex high-bandwidth electro-mechanical system to mitigate the effects ... |
|
| Fluid-Optic Interactions III (Adaptive-Optic) |
10 FEB 2003 |
28 pages |
| Authors:
Eric J. Jumper; NOTRE DAME UNIV IN DEPT OF AEROSPACE AND MECHANICAL ENGINEERING
|
| This report describes fluid-optic interaction research at the University of Notre Dame. When a laser beam propagates through a variable-index- of-refraction, turbulent fluid, its wavefront becomes aberrated, reducing associated optical-system performance. For flight Mach numbers above 0.6 Mach, "compressibility" effects in the flow past the aircraft become important in aberrating wavefronts (aero-optics). This report presents experimental validation for the mechanism responsible for these aberrations in high, subsonic-Mach, free shear-layer flows, ... |
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| Liquid Crystal Technology for Adaptive Optics: an Update |
2003 |
7 pages |
| Authors:
Sergio R. Restaino; Don M. Payne; Jeff T. Baker; Jonathan R. Andrews; Scott W. Teare; G. C. Gilbreath; Dave Dayton; John Gonglewski; NAVAL RESEARCH LAB WASHINGTON DC REMOTE SENSING DIV
|
| The idea of using liquid crystal (LC) devices as an adaptive optics component has been proposed by several authors. In recent years a vigorous research effort has been carried out, and it is still flourishing, in several countries. Mainly the research and experimental work has been concentrated in the USA, U.K. and Russia. There are several reasons why liquid crystals may represent a valid alternative to the traditional deformable mirror ... |
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| Improving the Performance of Air Force Adaptive Optics Systems Using High-Resolution Spatial Light Modulators with Deformable Mirrors: Final Report |
30 DEC 2002 |
43 pages |
| Authors:
Michael K. Giles; Mikhail Vorontsov; Michael Roggem; NEW MEXICO STATE UNIV LAS CRUCES
|
| This document presents a comprehensive technical summary of the most significant work accomplished on Air Force Office of Scientific Research Contract Number F49620-99-l-0342. Since closed loop wave front control (WFC) systems currently being developed by the Air Force have residual wave front errors that reduce image quality, New Mexico State University has developed methods to reduce those residual errors and improve the quality (Strehl ratio) of Air Force WFC systems. ... |
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| Compact Adaptive Optics Systems (CAOS) |
27 AUG 2002 |
11 pages |
| Authors:
A. H. Greenway; HERIOT-WATT UNIV EDINBURGH (UNITED KINGDOM) DEPT OF PHYSICS
|
| As feasibility study has been conducted to investigate whether compact adaptive optical (AO) systems based on the use of transparent wavefront modulators are viable. The results presented here consider the generic properties of suitable wavefront sensor technologies and establish sufficient conditions for their exploitation. Schemes by means of which these properties might be exploited in a multi-conjugate AO system are then considered. It is shown that the prospects for such ... |
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| High-Bandwidth Adaptive-Optic System |
05 JUN 2002 |
5 pages |
| Authors:
Eric J. Jumper; NOTRE DAME UNIV IN DEPT OF AEROSPACE AND MECHANICAL ENGINEERING
|
| This award was to procure a high-bandwidth adaptive-optic system. A system capable of operating at 20 kHz was contracted to be constructed by Boeing SVS, Albuquerque NM using hardware primarily furnished by Xinetics. The components and operational concept for the adaptive-optic system is described in this report. |
|
| Unconventional Laser Guide Stars and Wavefront Correction of Blue Starlight |
28 MAY 2002 |
10 pages |
| Authors:
Robert W. Hellwarth; UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES DEPT OF ELECTRICAL ENGINEERING
|
| In this project we established by theory and experiment (1) that a 1/ 4 Joule, 20 ns, ultraviolet laser pulse could create (near 20 km altitude) a return signal to the transmitting telescope that would appear, for 20 ns, to have a brightness temperature of millions of degrees, and thus serve as a guide star for high-order corrections of blue starlight, (2) that a much lower energy (approx. one hundred ... |
|
| Adaptive Optics, LLLFT Interferometry, Astronomy |
14 MAR 2002 |
10 pages |
| Authors:
Friedman; PUERTO RICO UNIV RIO PIEDRAS
|
| We propose to build a three telescope Michelson optical interferometer equipped with wavefront compensation technology as a demonstration and test bed for high resolution Deep Space Surveillance (DSS) and Astronomy. Each telescope will have a liquid crystal (LC) Adaptive Optics (AO) phase retarder capable of providing diffraction or near diffraction limited operation. We will combine the wavefronts from the three telescopes using a conventional beam recombination system and acquire and ... |
|
| Smart Structures for Control of Optical Surfaces |
MAR 2002 |
173 pages |
| Authors:
D. M. Sobers Jr; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The development of lightweight, large-aperture optics is of vital importance to the Department of Defense and the US Air Force for advancing remote sensing applications and improving current capabilities. Synthetic polymer optics offer weight and flexibility advantages over current generation glass mirrors, but require active control to maintain tight surface figure tolerances. This research explores the feasibility of using imbedded piezoelectric materials to control optical surfaces. Membrane-based and stiff piezo-controlled ... |
|
| Thermal Conditioning of the AEOS Telescope |
2002 |
10 pages |
| Authors:
Lewis C. Roberts Jr.; Paul D. Figgis; AIR FORCE RESEARCH LAB KIHEI MAUI HI DETACHMENT 15
|
| The AEOS telescope facility was designed for high angular resolution imagery. Part of that design is the inclusion of several air handling systems to maximize dome seeing. Four air conditioning units chill the telescope and dome air to the predicted nighttime temperature. There is a mirror purge system, which prevents moisture from condensing on the mirror by blowing desiccated air into the mirror cell. A laminar air system counteracts the ... |
|
| The Role of Adaptive Photorefractive Power Limiting on Acousto-Optic Radio Frequency (RF) Signal Excision |
DEC 2001 |
192 pages |
| Authors:
Dale M. Stevens; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH SENSORS DIRECTORATE
|
| Adaptive RF interference reduction for broadband communication systems continues to be problematic. The acousto-optic RF signal excision system offers real-time, narrowband RF interference, frequency domain filtering for broadband communication systems, but has been limited in its capability for adaptive processing and rejection of broadband RF interference. As a means to reduce these limitations, this dissertation examines the application of a novel photorefractive optical power limiting device to achieve adaptive notch ... |
|
| Calibration and Testing of the 6.5 M MMT Adaptive Optics System |
2001 |
210 pages |
| Authors:
Robert L. Johnson; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH
|
| This dissertation describes the development, calibration, and testing of the adaptive optics system for the 6.5 m Multiple Mirror Telescope. By employing a deformable secondary mirror, the MMT adaptive optics system uniquely solves several problems typical of astronomical adaptive optics systems. Extra components are eliminated, improving throughput and reducing emissivity. Since the adaptive secondary is integral to the telescope, a corrected beam is presented to any instrument mounted at Cassegrain ... |
|
| Encoding of Complex Valued Composite Functions onto Spatial Light Modulators in Real-Time |
07 DEC 2000 |
160 pages |
| Authors:
Robert W. Cohn; LOUISVILLE UNIV KY ELECTRO OPTICS RESEARCH INST AND NANOTECHNOLOGY CENTER
|
| Spatial light modulators (SLM) are used as real-time programmable diffractive optics for potential applications to multi-object laser designation of moving objects. For real-time situations in which prior knowledge is unavailable, fast on-line design algorithms are required. The time requirements rule out many iterative design methods currently used for fixed pattern diffractive optics. Instead, encoding methods that map desired complex values onto the available modulation values provide the fastest realizations. As ... |
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| Adaptive Filtering and Estimation for Control and Target Tracking |
06 DEC 2000 |
8 pages |
| Authors:
J. S. Gibson; CALIFORNIA UNIV LOS ANGELES DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
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| The main objectives of this project were to develop real-time numerical algorithms for adaptive filtering, identification, and control. Derivation of mathematical theory to analyze and predict the performance of the adaptive algorithms in the presence or unmodeled noise also was an important part of the project. Much of the research was aimed at supporting Airborne Laser-related research at the Air Force Research Laboratory. The algorithms developed were designed especially for ... |
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| Simulation of Low Light Level Adaptive Optics Systems |
28 JUN 2000 |
27 pages |
| Authors:
Christopher J. Solomon; KENT UNIV CANTERBURY (UNITED KINGDOM)
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| This report results from a contract tasking University of Kent as follows: The contractor will provide documentation for the computer program developed in contract F61775-98-WE079, and develop optimum adaptive optic designs for low-light-level applications that will handle generation of time- evolving turbulent wavefronts, adjustment of wind speed of the turbulent layers, adjustment of key observational parameters such as the iso-planatic patch size, and the ability ... |
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| DURIP-97 Sodium Guide Star Raman Laser |
30 APR 2000 |
9 pages |
| Authors:
Richard C. Powell; ARIZONA UNIV TUCSON OPTICAL SCIENCES CENTER
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| The goal of this project was the acquisition of a critical piece of research equipment. In this case the equipment was a solid state, intracavity Raman laser for sodium guide star applications. During the time of the grant, this was delivered and used for preliminary tests in our laboratory. The technology improvements necessary for a field version of the laser optimized for operation in an astronomical ... |
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Reports by Keyword(s)
*ADAPTIVE OPTICS
