| Quantum Sensors Program |
Aug-2009 |
82 pages |
| Authors:
Z Dutton; S Guha; N Stelmakh; M Vasilyev; P Kumar; F Wong; J Shaprio; G Deibner; G Burdge; H Yuen; J Habif; HARRIS CORP MELBOURNE FL
|
 | The resolution of a homodyne LADAR can be enhanced significantly by applying quantum optical techniques in the receiver. With a quantum image enhancer (QIE) inserted between the receive optics and the detector of a LADAR, an angular cell resolution improvement of 10x can be realized. The QIE is comprised of two key elements-a squeezed vacuum injector (SVI) that restores the high spatial frequencies lost by attenuation in soft-aperture entrance optics ... |
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| Fokker-Planck Model for Thermal Smoothing in Inhomogeneous Laser-Matter Interactions |
24-Jul-2009 |
16 pages |
| Authors:
Michael J Keskinen; NAVAL RESEARCH LAB WASHINGTON DC
|
| Using a fully kinetic 2D Fokker-Planck model, the generation and evolution of ion density perturbations from nonuniform laser deposition in a plasma slab have been studied. It is found that significant smoothing of the ion density perturbations from nonuniform optically smoothed single beam laser deposition can be achieved on hydrodynamic time scales over a long range of scale sizes. In addition, it is observed that the Fokker-Planck model predicts more ... |
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| Spray Nonuniformities in Gas-Centered Swirl-Coaxial Injectors (Preprint) |
Jul-2009 |
7 pages |
| Authors:
Malissa D Lightfoot; Stephen A Danczyk; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| Experimental studies of gas-centered swirl-coaxial (GCSC) injectors have revealed five basic types of nonuniformities in the spray. These nonuniformities can be classified as either affecting the centerline of the spray, with respect to the centerline of the injector, or affecting the temporal mass-distribution. The details of these behaviors are discussed as are possible driving factors and design criteria for avoidance. In general, high momentum flux operations are suggested for minimizing ... |
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| Thermal Inactivation of Bacillus Anthracis using Laser Irradiation of Micro-Etched Platforms |
Mar-2009 |
131 pages |
| Authors:
Jeffrey B Bacon; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The purpose of this research was to determine the probability of kill for a thermal inactivation strategy for use against biological agents; specifically the resilient endospore of Bacillus anthracis (Ba). The effort focused on short durations (milliseconds to several seconds) and temperatures (300 to 1300 K) simulating the periphery effects after an explosion generated by conventional munitions. For an improved statistical counting, applied microlithography techniques were used to produce micro-etched ... |
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| Assessment of Weather Sensitivites and Air Force Weather (AFW) Support to Tactical Lasers in the Lower Troposphere |
Mar-2009 |
83 pages |
| Authors:
Francesco J Echeverria; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT/DEPT OF ENGINEERING PHYSICS
|
| ATL scientists need to develop a full understanding of the interaction effects between a high-energy laser beam and the atmosphere through which it propagates. Achieving this understanding is important for many reasons. In particular, the high cost of DE weapons systems makes each propagation event expensive. Having an understanding of the atmosphere in which a high-energy laser propagates will increase efficiency and effectiveness of the ATL weapon system, which in ... |
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| First-Order Model of Thermal Lensing in a Virtual Eye |
Mar-2009 |
12 pages |
| Authors:
Clark; Robert J Thomas; Rebecca L Vincelette; Ashley J Welch; Benjamin A Rockwell; Clifton D III; TEXAS UNIV AT SAN ANTONIO
|
| An ABCD beam-propagation method was used to build a first-order mathematical model of a thermal lens effect from a near-infrared laser beam in water and ocular media. The model was found to fit experimental z-x scan data best when the thermo-optic coefficient dn/dT of liquid water at 292 K was -4.46x10(-5) K(-1). The physiological parameters of the human eye were simulated in a simple eye model using this fitted dn/dT ... |
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| Two-Point Scalar Time-Series Measurements in Turbulent Partially Premixed Flames |
Feb-2009 |
24 pages |
| Authors:
Galen B King; Normand M Laurendeau; Michael W Renfro; PURDUE UNIV LAFAYETTE IN SCHOOL OF MECHANICAL ENGINEERING
|
| The technique of Picosecond Time-Resolved Laser-Induced Fluorescence (PITL1F) was expanded to enable two-point hydroxyl (OH) series concentration time series measurements of turbulent jet flames. Measurements were obtained with two-point separation along the radial direction of the jet (delta r), i.e., the propagation direction of the horizontal laser beam, as well as axial two-point separations, i.e. along the axis of the jet, i.e., the z-direction. As the jet configuration is statistically ... |
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| Ablation and Plasma Formation During Directed Energy Testing |
31-Dec-2008 |
11 pages |
| Authors:
Iain D Boyd; MICHIGAN UNIV ANN ARBOR
|
| Continuous radio-wave telemetry is required during planned tests of directed-energy weapons systems in order to characterize in situ the effects of laser irradiation on different target materials. Unfortunately, the incident radiation can cause disruption of the radio signal during the directed-energy testing. Several phenomena associated with directed-energy impact can lead to communication path losses, such as ablation, charged particle emission, charring, and chemical changes in the target materials. Directed-energy impact ... |
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| Theoretical Study of the Saturated Stage of a Relativistic Magnetron |
30-Nov-2008 |
149 pages |
| Authors:
D J Kaup; DJ KAUP INC WINTER SPRINGS FL
|
| The saturated stage of a magnetron or a cross-field amplifier is when the device has powered up and is steadily delivering power. Theoretical studies of this stage had suggested that when the dc current would become sufficiently large in comparison with the rf current, then no steady state solution could be expected to exist. Attempts were made to develop a numerical code which would allow one to numerically solve for ... |
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| Range Precision of LADAR Systems |
01-Sep-2008 |
198 pages |
| Authors:
Steven Johnson; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| A key application of Laser Detection and Ranging (LADAR) systems is measurement of range to a target. Many modern LADAR systems are capable of transmitting laser pulses that are less than a few nanoseconds in duration. These short-duration pulses provide excellent range precision. However, randomness in the detected laser signals places limits on the precision. The goal of this dissertation is to quantify the range precision limits of LADAR systems. ... |
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| Nonlinear Detection, Estimation, and Control for Free-Space Optical Communication |
17-Aug-2008 |
200 pages |
| Authors:
Arash Komaee; MARYLAND UNIV COLLEGE PARK OFFICE OF RESEARCH ADMINISTRATION AND ADVANCEMENT
|
| In free-space optical communication, the intensity of a laser beam is modulated by a message, the beam propagates through free-space or atmosphere, and eventually strikes the receiver. At the receiver, an optical sensor converts the optical energy into an electrical signal, which is processed to reconstruct the original message. The promising features of this communication scheme such as high-bandwidth, power efficiency, and security, render it a viable means for high ... |
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| High-Speed Blade Vibration in a Transonic Compressor |
01-Jun-2008 |
57 pages |
| Authors:
William P Murphy; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This experiment was conducted to measure transverse vibrations of the blades in a transonic compressor rig at the Naval Postgraduate School. The compressor was instrumented with non-invasive laser light probes to measure changes in time of arrival of all the blades, relative to an expected arrival time. These times were then converted to blade deflections. Results proved that the primary observed vibration was a first bending mode. The frequencies that ... |
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| Laser Spectroscopy of Levitated Microparticles in Molecular Plasmas |
27-May-2008 |
20 pages |
| Authors:
Paul B Davies; CAMBRIDGE UNIV (UNITED KINGDOM)
|
| During the past decade there has been increasing interest in the Chemistry and Physics of small particles in low temperature electric plasmas. This project aims to study spherical particles with the dimensions of microns (microspheres) levitated in molecular plasmas. A non invasive optical technique, Raman spectroscopy, is being used to probe the surface of the microspheres. Enhancement of the Raman signal will be achieved using whispering gallery modes (wgm's) in ... |
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| Image Science Research for Speckle-based LADAR (Speckle Research for 3D Imaging LADAR) |
03 APR 2008 |
32 pages |
| Authors:
Nicholas George; ROCHESTER UNIV NY OFFICE OF RESEARCH AND PROJECT ADMINISTRATION
|
| We propose a basic study of image science topics related to a new class of speckle-based laser-ranging radars (LADAR). For this imaging radar we study two basic system configurations: a wavefront sensing configuration and an imaging configuration. Three major research projects are (1) study of speckle patterns to establish 3D qualitative features for a remote object (2) study of performance of this compact ladar at photon counting light levels and ... |
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| Characterization and Prediction of Clear Air and Optical Stratospheric Turbulence for DoD High Altitude Platforms |
21 MAR 2008 |
52 pages |
| Authors:
Alex Mahalov; Basi Nicolaenko; ARIZONA STATE UNIV TEMPE
|
| Stratospheric Clear Air Turbulence (CAT) is a major challenge to the safety, controllability and flight path optimization of the Global Hawk, Predator and other Unmanned Aerial Vehicles (UAVs) and Platforms. Optical Turbulence (OT) layers impact on the polarization and focusing of laser beams in communication systems and the Airborne Laser (ABL). The completed fundamental research project investigated the microscale physics of the upper troposphere/lower stratosphere (UTLS), closely correlating field measurements, ... |
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| Separated Turbulent Shear Layer Modification Via Feedback Flow Control and Feedback Flow Control with Experiment Based Order Reduction |
Mar-2008 |
16 pages |
| Authors:
James H Myatt; Ryan F Schmit; Marlyn Y Andino; Ryan D Wallace; Russell C Camphouse; Mark N Glauser; SYRACUSE UNIV NY DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
|
| Losses in the performance and effectiveness of optical systems are caused by turbulence. In particular, separated turbulent flow phenomena are present in several aero-optics applications. In an effort to reduce the adverse effects of turbulence, we are exploring the use of both open and closed-loop flow control. A series of experiments were performed in Syracuse University and Wright-Patterson Air Force Base (WPAFB) facilities using two test models, a quarter- and ... |
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| Characterization of an Electro-Absorption Modulator Design With High-Dynamic Range for Broadband Analog Applications |
Mar-2008 |
15 pages |
| Authors:
Paul Yu; Ivan Shubin; Terrance McDonald; Charles Schick; Paul Cook; Henry Zmuda; Songsheng Tan; Nancy Stoffel; Brian McKeon; Richard Michalak; Reinhard Erdmann; Rebecca Bussjager; Xiaobo Xie; AIR FORCE RESEARCH LAB ROME NY
|
| An electro-absorption modulator (EAM) is designed to optimize dynamic range performance over 20 GHz bandwidth. The single stripe waveguide enables an extremely compact and integrated package to be fabricated with single mode fiber pigtails. The transfer function's shape permits suppression of higher order intermodulation products, yielding a spur-free dynamic range exceeding that of Mach-Zehnder designs. A dilute optical core diverts energy flow from absorbing layers into a low loss waveguide; ... |
|
| Theoretical Study of the Saturated Stage of a Relativistic Magnetron |
27-Feb-2008 |
6 pages |
| Authors:
D J Kaup; DJ KAUP INC WINTER SPRINGS FL
|
| The saturated stage of a magnetron or a cross-field amplifier is when the device has powered up and is steadily delivering power. Theoretical studies of this stage had suggested that when the dc current would become sufficiently large in comparison with the rf current, then no steady state solution could be expected to exist. Attempts were made to develop a numerical code which would allow one to numerically solve for ... |
|
| Laser Induced Shock Waves and Vaporization in Biological System and Material Science |
30 JAN 2008 |
6 pages |
| Authors:
Bernard S. Gerstman; FLORIDA INTERNATIONAL UNIV MIAMI DEPT OF PHYSICS
|
| Theoretical and computational work was carried out to investigate the underlying physical mechanisms that cause laser induced biological damage and material stress. In order to cause damage to the absorbing material, the electromagnetic energy of the laser pulse must be converted to thermo-mechanical energy. We have developed a computational model that allows the calculation of damage resulting from a laser pulse of any duration or energy due to temperature rise, ... |
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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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| Four Dimensional Analysis of Free Electron Lasers in the Amplifier Configuration |
DEC 2007 |
81 pages |
| Authors:
Juan M. Aguilar; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Free electron lasers (FELs) are devices used worldwide for several purposes. In the military, especially in the Navy, they can be used for self-defense against missiles, and small boats. Installed on a ship, an FEL represents a multi-mission, deep magazine, long range weapon. This thesis will describe briefly the basic components and principles of operation. It also explores, by simulations, the effects of changing some of the parameters that generate ... |
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| Joint Image and Pupil Plane Reconstruction Algorithm based on Bayesian Techniques |
DEC 2007 |
112 pages |
| Authors:
James D. Phillips; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
|
| The focus of this research was to develop an joint pupil and focal plane image recovery algorithm for use with coherent LADAR systems. The benefits of such a system would include increased resolution with little or no increase in system weight and volume as well as allowing for operation in the absence of natural light since the target of interest would be actively illuminated. Since a pupil plane collection aperture ... |
|
| Role of Superoxide Dismutase in the Photochemical Response of Cultured RPE Cells to Laser Exposure at 413 nm |
Nov-2007 |
9 pages |
| Authors:
Robert J Thomas; Michael S Foltz; Michael L Denton; Kurt J Schuster; Larry E Estlack; NORTHROP GRUMMAN SAN ANTONIO TX WARFIGHTER CONCEPTS AND APPLICATIONS DEPT
|
| Thresholds for photochemical damage were performed in RPE cell lines (artificially pigmented) taken from either human (hTERT-RPE1), wild type (wt) mouse, or transgenic mice deficient (+/-) in either superoxide dismutase 1 (SOD1) or SOD2. The four cell lines were characterized by immunohistochemical and immunoblot analyses to determine relative abundance of the SOD proteins. There was no difference in sensitivity between the human, murine wt and murine SOD1-deficient cells, whereas there ... |
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| Review of Laser Lightcraft Propulsion System (Preprint) |
16 OCT 2007 |
13 pages |
| Authors:
Eric W. Davis; Jr Mead Franklin B.; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| Laser-powered "Lightcraft" systems that deliver nano-satellites to LEO have been studied for the Air Force Research Laboratory (AFRL). The study was built on the extensive Lightcraft laser propulsion technology already developed by theoretical and experimental work by the AFRL's Propulsion Directorate at Edwards AFB, CA. Here we review the history and engineering-physics of the laser Lightcraft system and its propulsive performance. We will also review the effectiveness and cost of ... |
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| Simultaneous Measurement of Air-water Interface Slope and the Point Spread Function for the Propagation of Laser Light |
01 OCT 2007 |
5 pages |
| Authors:
Jules S. Jaffe; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| The objective of this project funded by ONR (grant # N00014-06-1-0374) was to measure, understand and be able to predict the propagation of light through the air-sea interface under various sea states. Results indicate that the under sea scattered light patterns are quite simple in mild sea state and wind (< 5 mph) however, the increase in sea state leads to various types of patterns that are currently under analysis. ... |
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| Development of THz Fiber Lasers |
12-Sep-2007 |
8 pages |
| Authors:
Xi-Cheng Zhang; Albert Redo-Sanchez; Gernot S Pomrenke; RENSSELAER POLYTECHNIC INST TROY NY
|
| There is no Current commercially available THz fiber Laser on the market, and there is no any report successful demonstration of THz fiber lasers in literatures. Our DURIP project is to develop a THz fiber Laser on a novel photonic crystal fiber technique. The THz fiber laser has several important characteristics; sm portability, room temperature operation, and high output power. ALL provide advantages over current THz La a new high-power, ... |
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| Modeling and Simulation of a Laser Deposition Process (Preprint) |
Sep-2007 |
14 pages |
| Authors:
Kevin Slattery; Hsin-Nan Chou; Mary Kinsella; Frank Liou; Joseph Newkirk; Zhiqiang Fan; Heng Pan; MISSOURI UNIV-ROLLA
|
| A laser deposition process involves the supply of metallic powders into a laser-heated spot where the powder is melted and forms a melt puddle which quickly solidifies into a bead. In order to design an effective system, the laser beam, the powder beam, and their interactions need to be fully understood. In this paper, the laser-material interaction within the melt pool is reported using a multi-scale model: a macroscopic model ... |
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| High-Speed Digital-Image Data Acquisition, Processing, and Visualization System for Turbulent Mixing and Combustion |
25 MAY 2007 |
13 pages |
| Authors:
Paul E. Dimotakis; CALIFORNIA INST OF TECH PASADENA DEPT OF AERONAUTICS
|
| This report summarizes an equipment and instrumentation system for high-speed digital image data acquisition and processing. The research program targets the physics of turbulence, mixing, and combustion, focusing on high-speed environments. The system includes components for Planar Laser Induced Fluorescence (PLIF), flame-speed, and ignition and extinction measurements of laminar flames at variable pressure; tracking flow structures in a high-speed mixing layer using high-speed color schlieren; laser-beam manipulation and volume scanning ... |
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| Localized Synthesis of Silicon Nanocrystals in Silicon-rich SiO2 by CO2 Laser Annealing |
01 MAY 2007 |
14 pages |
| Authors:
Gong-Ru Lin; NATIONAL CHIAO TUNG UNIV HSINCHU (TAIWAN) INST OF ELECTRO-OPTICAL ENGINEERING
|
| The optical properties of a SiOx film rapid-thermal-annealed "RTA" by CO2 laser are primarily investigated. The micro-photoluminescence "-PL" and HRTEM analysis indicate that the precipitation of random-oriented Si nanocrystals can be initiated when laser intensity "Plaser" larger than 4.5 kW/cm2. At Plaser of 6 kW/cm2, the Si nanocrystals exhibits a largest diameter of 8 nm and a highest density of 4.51016 cm-3, which emits strong PL at 790-825 nm. The ... |
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| Room-Temperature, Near IR Fluorescence of High Optical Quality KTP (Postprint) |
APR 2007 |
10 pages |
| Authors:
S. M. Hegde; K. L. Schepler; R. D. Peterson; D. E. Zelmon; DAYTON UNIV OH RESEARCH INST
|
| We investigated room temperature fluorescence in the 500-900nm spectral region from high optical quality, polished and uncoated KTP crystals from three different commercial vendors. The crystals were all cut into 5x5x5 mm3 cubes with their dielectric axes along the cube edges. The pump source was a tripled Nd:YAG laser operating at 355nm and 7mJ energy having 3ns pulse width and 100Hz pulse repetition rate. Samples from two vendors showed low ... |
|
| Optical Tuning of the Reflection of Azobenzene Liquid Crystal Doped Cholesterics (Preprint) |
APR 2007 |
43 pages |
| Authors:
Uladzimir A. Hrozhyk; Svetlana V. Serak; Nelson V. Tabiryan; Timothy J. Bunning; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| Mixtures of cholesteric liquid crystals doped with high clearing temperature azobenzene nematic liquid crystals are shown to possess large, fast, and reversible dynamic photosensitive features. Selective wavelengths shifts approaching 400 nm are reported and depending on the host cholesteric liquid crystal, both red-shifted and blue-shifted wavelength changes can be induced. The photoinduced states of these material systems are shown to be stable for long periods of time upon removal of ... |
|
| New Generation Photonics Materials: Design, Development, Characterization, and Applications |
31 MAR 2007 |
37 pages |
| Authors:
Paras N. Prasad; Guang S. He; STATE UNIV OF NEW YORK AT BUFFALO INST FOR LASERS PHOTONICS AND BIOPHOTONICS
|
| Significant research achievements have been accomplished in development of multi-photon active materials and applications as well as of novel nanocomposites materials for opt-electronic technology. The specific research progress achieved by this grant support can be summarized as follows. (I) Nonlinear optical limiting and stabilization of 1064-nm laser pulses using a novel two-photon absorbing liquid dye salt system. The major advantage of using a neat liquid dye salt as the two-photon ... |
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| Experimental Characterization of Near-Infrared Laser Energy Absorption, Scattering, and Transmittance in Biological Tissue |
MAR 2007 |
86 pages |
| Authors:
John Laffitte; David Roelant; Michael L. Denton; Robert J. Thomas; FLORIDA INTERNATIONAL UNIV MIAMI APPLIED RESEARCH CENTER
|
| Many infrared (IR) laser systems are being used in tactical military ground and airborne applications. Understanding the biological impact of IR laser energy absorbed by skin and ocular tissues is essential for developing models that can predict collateral hazards. Due to the lack of IR wavelength-dependent microscopic cross sections for skin, research is needed to understand biological damage caused by IR radiation in tissues. Florida International University (FIU) carried out ... |
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| Computational Analysis of Hybrid Two-Photon Absorbers with Excited State Absorption |
MAR 2007 |
18 pages |
| Authors:
M. J. Potasek; DEVANEY (A J) ASSOCIATES BOSTON MA
|
| This work represents the joint work of several groups including numerical calculations and experiments. Numerical calculations were performed for the propagation of a femtosecond laser beam through an optical path and a nonlinear absorber. The results were compared with experiments performed under similar conditions. There was excellent agreement between calculations and experiments at low input energy. However, further additions must be done to the calculation of the optical path for ... |
|
| Optical Tuning of the Reflection of Cholesterics Doped with Azobenzene Liquid Crystals (Postprint) |
2007 |
11 pages |
| Authors:
Timothy J. Bunning; Uladzimir A. Hrozhyk; Svetlana V. Serak; Nelson V. Tabiryan; BEAM ENGINEERING FOR ADVANCED MEASUREMENTS CO WINTER PARK FL
|
| Mixtures of cholesteric liquid crystals doped with high clearing temperature azobenzene nematic liquid crystals are shown to possess large, fast, and reversible dynamic photosensitive features. Selective wavelength shifts approaching 400 nm are reported, and depending on the host cholesteric liquid crystal, both red-shifted and blue-shifted wavelength changes can be induced. The photoinduced states of these material systems are shown to be stable for long periods of time upon removal of ... |
|
| Estimates of Atmospheric Distortion Number for Nonlinear Refraction |
2007 |
14 pages |
| Authors:
J. R. Roadcap; P. J. McNicholl; R. R. Beland; G. Y. Jumper; BOSTON COLL CHESTNUT HILL MA INST FOR SCIENTIFIC RESEARCH
|
| A characteristic nondimensional distortion number Nd was derived in the 1970s that allows inference of the degree of nonlinear refraction or thermal blooming associated with an atmospheric laser path. For a continuous-wave (CW) laser with a Gaussian-shaped beam, the distortion number is a function of several variables including laser power and aperture size, optical wavelength, atmospheric absorption and extinction, index of refraction, temperature, air density, and the air speed or ... |
|
| High Energy Laser Progressive Wavefront Modeling |
09 DEC 2006 |
28 pages |
| Authors:
Donald M. Needham; Michael J. Izbicki; NAVAL ACADEMY ANNAPOLIS MD DEPT OF COMPUTER SCIENCE
|
| High energy lasers have the potential to revolutionize naval warfighting by providing a weapons platform that has greater precision and speed than anything currently available. These lasers can be mounted on ships for surface warfare or mounted on satellites for strikes anywhere around the world. Crucial to the development of these lasers is an understanding of how different atmospheric conditions affect the laser's propagation and the shape of the beam ... |
|
| Effect Of Substituents On UV-Vis Spectra And RSA Properties Of Phthalocyanine Compounds |
NOV 2006 |
8 pages |
| Authors:
Jan Andzelm; Adam Rawlett; Joshua Orlicki; James Snyder; Kim Baldridge; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| The use of optically transparent materials to modulate or impede laser light in a real time setting is significant. This goal stimulates an interest in metalloporphyrins, phthalocyanines, naphthalocyanins and their derivatives. The most desired derivatives would be optically transparent, absorb laser light and also be soluble in water. Phthalocyanines (PC) with their stable, planar square structure and highly delocalized pi-electron system, are being used in numerous technological applications, such as ... |
|
| All-Optical, Photonic Band Gap Modulation in Azobenzene Liquid Crystal Doped Cholesterics (Preprint) |
OCT 2006 |
30 pages |
| Authors:
Uladzimir A. Hrozhyk; Svetlana V. Serak; Nelson V. Tabiryan; Timothy J. Bunning; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| Cholesteric liquid crystals doped with high clearing temperature azobenzene liquid crystals are shown to possess large, fast, and reversible dynamic photosensitive features. Selective wavelengths shifts approaching 400 nm are reported and depending on the host cholesteric liquid crystal, both red-shifted and blue-shifted wavelength changes can be induced. The photoinduced states of these material systems are shown to be stable for long periods of time upon removal of the radiation source, ... |
|
| Dual Fine Tracking Control of a Satellite Laser Communication Uplink |
14 SEP 2006 |
190 pages |
| Authors:
Louis A. Noble; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
|
| A dual fine tracking control system (FTCS) is developed for a single aperture optical communication receiver to compensate for high frequency disturbances affecting tracking of two incident laser communication beams. The optical communication receiver resides within a payload module aboard a geosynchronous satellite, while each laser communication transmitter is housed within a module aboard a high altitude unmanned aerial vehicle (UAV). In addition to platform specific disturbances, the impact of ... |
|
| 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 ... |
|
| Beam Control of Extremely Agile Relaying Laser Source for Bifocal Relay Mirror Spacecraft |
SEP 2006 |
109 pages |
| Authors:
Scott L. Johnson; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF MECHANICAL AND ASTRONAUTICAL ENGINEERING
|
| The concept of controlling optical laser beams on spacecraft for acquisition, tracking and pointing purposes is quickly becoming a reality. As a result, fine pointing of laser beams is turn out to be an increasingly important research topic. A unique testbed was constructed in order to study and develop new methods for laser beam control. This testbed, the Moving Target-Source Test Fixture (MTSTF), hosts a laser source, the Extremely Agile ... |
|
| Three-Dimensional Change Detection With the Use of an Evidence Grid |
SEP 2006 |
27 pages |
| Authors:
Gary A. Haas; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| In this study, the objective is to find changes in terrain geometry, which are encountered by a patrolling unmanned ground vehicle (UGV) from one patrol run to another. The UGV is equipped with a streaming imaging ladar (laser radar) that measures the distance to the nearest surface at an array of points spanning a prism-shaped field of view and with a navigation system that measures the location of the UGV ... |
|
| A Novel Temperature Measurement Approach for a High Pressure Dielectric Barrier Discharge Using Diode Laser Absorption Spectroscopy (Preprint) |
SEP 2006 |
18 pages |
| Authors:
R. J. Leiweke; B. N. Ganguly; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH PROPULSION DIRECTORATE
|
| A tunable diode laser absorption spectroscopic technique is used to measure both electronically excited state production efficiency and gas temperature rise in a dielectric barrier discharge in argon. The effect of voltage pulse rise time on the power deposition and electronically excited state production efficiency have been measured over a operating pressure range from 100 Torr up to 500 Torr. |
|
| Expedient Gap Definition Using 3D LADAR |
SEP 2006 |
108 pages |
| Authors:
Lulu Edwards; Sarah R. Jersey; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS GEOTECHNICAL AND STRUCTURES LAB
|
| This report presents a summary of the testing and analyses performed to determine the capabilities of a 3D LADAR (laser detection and ranging) system developed by Autonomous Solutions, Inc. (ASI). Under the direction of the U.S. Army Engineer Research and Development Center (ERDC), ASI has developed an algorithm to reduce the 3D point cloud acquired with the LADAR system into sets of 2D profiles that describe the terrain. This report ... |
|
| Laser Space Propulsion Overview (Preprint) |
22 AUG 2006 |
|
| Authors:
Claude Phipps; James Luke; Wesley Helgeson; PHOTONIC ASSOCIATES SANTA FE NM
|
 | In this paper, we review the history of laser space propulsion from its earliest theoretical conceptions to modern practical applications. Applications begin with the "Lightcraft" flights of Myrabo and include practical thrusters for satellites now completing development as well as proposals for space debris removal and direct launch of payloads into orbit. We consider laser space propulsion in the most general sense, in which laser radiation is used to propel ... |
|
| Boeing Demonstrates Aerospace Relay Mirror System -- Presentation (Postprint) |
07-Aug-2006 |
4 pages |
| Authors:
Maria McCullough; Marc Selinger; BOEING INTEGRATED DEFENSE SYSTEMS SAINT LOUIS MO
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| Boeing and the U.S. Air Force achieved major progress in their relay system development program by successfully redirecting a laser beam to a target using their aerospace relay mirror system (ARMS). |
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| Elaboration and Characterization of Nano-Sized AlxMoyOz/Al Thermites |
JUL 2006 |
13 pages |
| Authors:
M. Comet; D. Spitzer; INSTITUT FRANCO-ALLEMAND DE RECHERCHES DE SAINT-LOUIS (FRANCE) DEUTCH-FRANZOSINSTITUT
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| A new process to control the reactivity of thermites containing molybdenum trioxide (MoQ3) and aluminium (Al) has been developed at the Institut franco-allemand de recherches de Saint Louis (ISL). This process consists of a new sol-gel method nano-sized mixed AlxMoyOz phases whose structure is correlated to the chemical composition. It is possible to adjust the energetic properties of the thermites obtained through physical mixing of these phases with nano-sized aluminium ... |
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| Hazards and Possibilities of Optical Breakdown Effects Below the Threshold for Shockwave and Bubble Formation |
JUL 2006 |
95 pages |
| Authors:
Alfred Vogel; LUBECK MEDICAL UNIV (GERMANY) MEDICAL LASER CENTER
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| Femtosecond laser pulses enable the creation of spatially extremely confined chemical, thermal, and mechanical effects in biological media and other transparent materials via free-electron generation through nonlinear absorption. The principle mechanisms of femtosecond laser interaction with biomaterials are not only relevant for nanosurgery with tightly focused laser pulses but also for applications such as intrastromal corneal refractive surgery or presbyopia treatment where the laser pulses are focused at smaller numerical ... |
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| Devices and Control Strategies for AD HOC Optical Communications Networks |
26 JUN 2006 |
11 pages |
| Authors:
John Baillieul; Thomas Bifano; BOSTON UNIV MA DEPT OF AEROSPACE AND MECHANICAL ENGINEERING
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| The research under this project has been aimed at proving the potential value of key elements (both hardware and operational concepts) that we plan to develop in initiating an ambitious program of research to develop a radical new technology for high-bandwidth, stealthy communication over free-space optical links. The results of the project have been several prototype systems which integrate optical components (a MEMS-based spatial light modulator (SLM) integrated with a ... |
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LASER BEAMS
