| Control of Resonances and Optical Properties of Plasmonic-Patch Metamaterials |
01 Aug 2012 |
41 pages |
| Authors:
Anantha Ramakrishna; INDIAN INST OF TECH KANPUR
|
 | The primary objective of this research is to study the dispersion of the surface plasmon to correlate the physical origins or various phenomena linked to plasmonic effects. The goal is to fabricate multilayered plasmonic metamaterials and experimentally study their photonic properties when nonlinear amplifying dye molecules are imbedded in the structures. |
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| Three Dimensionally Interconnected Silicon Nanomembranes for Optical Phased Array (OPA) and Optical True Time Delay (TTD) Applications |
Jun 2012 |
93 pages |
| Authors:
Ray T Chen; TEXAS UNIV AT AUSTIN DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| In summary, during this period of MURI program, our team has made significant progress on both optical phased array (OPA) using actively tuned unequally spaced nano-waveguide arrays and optical true time delay (TTD) devices using photonic crystal waveguides where are all made on silicon nanomembranes. Integrated photonic circuit including 1x12 multimode interference (MMI) coupler, 12 waveguide adiabatic tapers, 12 thermal optical phase tuners, 12 delay lines and 12 non-equally spaced ... |
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| Recombinant Reflectin-Based Optical Materials |
Jan 2012 |
13 pages |
| Authors:
Guokui Qin; Patrick B Dennis; Yuji Zhang; Xiao Hu; Jason E Bressner; Zhongyuan Sun; Wendy J Crookes-Goodson; Rajesh R Naik; Fiorenzo G Omenetto; David L Kaplan; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| Reflectins are a unique group of structural proteins involved in dynamic optical systems in cephalopods that modulate incident light or bioluminescence. We describe cloning structural characterization, and optical properties of a reflectinbased domain, refCBA, from reflectin 1a of Hawaiian bobtail squid, Euprymna scolopes. Thin films created from the recombinant protein refCBA display interesting optical features when the recombinant protein is appropriately organized. RefCBA was cloned and expressed as a soluble ... |
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| Mode-matched Fano Resonances For All-optical Switching Applications (Preprint) |
Dec 2011 |
13 pages |
| Authors:
Nadia Mattiucci; Giuseppe D'Aguanno; Mark J Bloemer; AEGIS TECHNOLOGIES GROUP INC HUNTSVILLE AL NANOGENESIS DIV
|
| We introduce the concept of mode-matched Fano resonances in one-dimensional, subwavelength, diffraction gratings. These resonances are characterized by an extremely high quality (Q)-factor and lend themselves well for applications to ultra-low power, all-optical switching devices at telecommunication wavelengths. We provide examples of diffraction gratings made of a chalcogenide glass (As2S3) where, thanks to the mode-matched Fano resonances, all-optical switching is obtained at local field intensities well below the photo-darkening threshold ... |
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| UV and Visible Harmonic Generation Through Enhanced Transmission from GaAs-filled Nanocavities |
Oct 2011 |
4 pages |
| Authors:
M A Vincenti; D de Ceglia; V Roppo; M Scalora; ARMY MISSILE RESEARCH DEVELOPMENT AND ENGINEERING CENTER REDSTONE ARSENAL AL
|
| A theoretical study of harmonic generation from a silver grating having slits filled with GaAs has been conducted. The enhanced transmission regime that guarantees high field localization inside the slits, and the phase-locking mechanism that take place between the pump and its harmonics allows enhanced harmonic generation under conditions of high absorption at visible and UV wavelengths. |
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| Tunable Microfluidic Microlasers |
Sep 2011 |
21 pages |
| Authors:
Francesco Simoni; UNIVERSITA POLITECNICA DELLE MARCHE ANCONA (ITALY)
|
| According to the lines of the proposed activity we have completed the following tasks: a) recording and characterization of holographic gratings in different polymeric materials and their integration in optofluidic circuits; b) investigation of liquid crystals alignment under microfluidic conditions; c) design and test of laser geometries and demonstration of laser emission. The objective of getting laser tuning by exploiting the orientational properties of liquid crystal in microfluidic condition has ... |
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| High Power Multimode Fiber Master Oscillator Power Amplifier (MOPA) with Stimulated Brillouin Scattering (SBS) Beam Cleanup and Phase Conjugation |
Sep 2011 |
20 pages |
| Authors:
John E McElhenny; Jeffrey O White; Steven D Rogers; ARMY RESEARCH LAB ADELPHI MD SENSORS AND ELECTRON DEVICES DIRECTORATE
|
| This is a study, at the 102 W power level, of the feasibility of using stimulated Brillouin scattering (SBS) beam cleanup and wavefront reversal to obtain 105 W of single-mode output from a multi-mode fiber amplifier. These techniques allow power scaling by circumventing the problem of maintaining single-mode operation in a fiber with a large core. We have achieved 51-W peak power (34 W average) out of the beam cleanup ... |
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| Using a Volume Bragg Grating Instead of a Faraday Isolator in Lasers Incorporating Stimulated Brillouin Scattering Wavefront Reversal or Beam Cleanup |
29 Aug 2011 |
6 pages |
| Authors:
John E McElhenny; Jeffrey O White; Steven D Rogers; Tigran Sanamyan; Leonid B Glebov; Oleksiy Mokhun; Vadim I Smirnov; ARMY RESEARCH LAB ADELPHI MD
|
| A master-oscillator power-amplifier with stimulated Brillouin scattering (SBS) beam cleanup or wavefront reversal typically incorporates a Faraday isolator to outcouple the Stokes light, limiting the power scalability. Volume Bragg gratings (VBGs) have the potential for scaling to higher powers. We report here the results of tests on a VBG designed to resolve wavelengths 0.060 nm apart, corresponding to the 16 GHz frequency shift for SBS backscattering at 1064 nm in ... |
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| Coherent Beam Combining Element for Five 150-W Fiber Lasers by Volume Bragg Gratings in PTR Glass |
03 Aug 2011 |
29 pages |
| Authors:
Leonid Glebov; OPTIGRATE LP AND T INC ORLANDO FL
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| A compact beam combiner based on multiplexed volume Bragg gratings (VBGs) recorded in photo-thermo-refractive (PTR) glass was demonstrated. This element was designed to provide efficient superposition of 5 coherent beams from 150 W fiber amplifiers operating at the testbed developed at AFRL (KAFB). Five VBGs were multiplexed in a PTR glass wafer in such a way that they have common (degenerate) Bragg angle. Thus it will take the 5 beams ... |
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| Computational Electromagnetics |
20 Feb 2011 |
9 pages |
| Authors:
Oscar P Bruno; CALIFORNIA INST OF TECH PASADENA
|
| The overall work in the proposed areas for the duration of this effort, through November 2010, is detailed in what follows. In particular, our efforts gave rise to 1) Volumetric propagation and scattering solvers for propagation through thousand of kilometers of realistic three-dimensional atmospheres (completed in 2009); 2) Development of high-order solvers, which do not suffer from restrictive CFL conditions, for solution of time-dependent wave-propagation problems in inhomogeneous media; 3) ... |
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| Optical Properties of Sub-Wavelength Dielectric Gratings and Their Application for Surface Enhanced Raman Scattering |
Feb 2011 |
20 pages |
| Authors:
Min Hu; David Fattal; Jingjing Li; Xuema Li; Stanley R Williams; Zhiyong Li; HEWLETT-PACKARD LABS PALO ALTO CA
|
| We fabricated and measured the far-field optical properties of a sub-wavelength Si3N4 (silicon nitride) two dimensional grating. Frequency-dependent transmission measurements from a white-light source revealed that both transverse magnetic (TM) and transverse electric (TE) modes were excited on the grating. We determined the dispersion relations of the modes by tilting the sample with respect to the incoming light beam and measuring the frequency shift of the absorption features. By comparing ... |
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| WHITE-LIGHT SAGNAC INTERFEROMETER FOR SNAPSHOT POLARIMETRIC AND MULTISPECTRAL IMAGING |
15 Mar 2010 |
12 pages |
| Authors:
Michael W Kudenov; Matthew E Jungwirth; Eustace L Dereniak; Grant R Gerhart; ARIZONA UNIV TUCSON OPTICAL SCIENCES CENTER
|
| A common technique, referred to as channeled imaging polarimetry (ClP), enables the snapshot acquisition of the 2- dimensional Stokes parameters of an arbitrary scene or sample. It achieves this by amplitude modulating the Stokes parameters onto various interference-based spatial carrier frequencies. While this technique has utility. it often suffers from low signal-lo-noise ratios, in remote sensing scenarios. due to its requirement of narrow spectral bandwidth illumination 3 nm in the ... |
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| New Thermal Infrared Hyperspectral Imagers |
Oct 2009 |
12 pages |
| Authors:
Hannu Holma; Antti-Jussi Mattila; Timo Hyvarinen; SPECIM-SPECTRAL IMAGING LTD OULU (FINLAND)
|
| The aim for this paper is to present designs and performance characteristics of the new push-broom hyperspectral imagers in thermal wavelength region. The guiding motive for this work has been to design high performance instruments with good image quality, compact size and easy operation for different application requirements. The studies involve imaging systems based on both MCT and microbolometer detector. All the systems base on push-broom imaging spectrograph with transmission ... |
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| Operation Manual for Measurement and Discrete Layer Peeling of Fibre Bragg Grating Spectra |
FEB 2008 |
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| Authors:
Chris Brooks; Claire Davis; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION VICTORIA (AUSTRALIA) AIR VEHICLES DIV
|
 | This document is a manual detailing the operation of an interrogation system for measuring the complex reflection spectrum of a Bragg grating. The manual also describes custom-designed software for deconvolving this data to determine the pitch profile of the grating by using a discrete layer peeling technique. This information can be used to determine the strain profile experienced by the grating in cases where the grating length spans the localised ... |
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| Initial Results From the USNO Dispersed Fourier Transform Spectrograph |
25 JAN 2007 |
19 pages |
| Authors:
Arsen R. Hajian; Bradford B. Behr; Andrew T. Cenko; Robert P. Olling; David Mozurkewich; J. T. Armstrong; Brian Pohl; Sevan Petrossian; Kevin H. Knuth; Robert B. Hindsley; NAVAL OBSERVATORY WASHINGTON DC
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| We have designed and constructed a dispersed Fourier transform spectrometer (dFTS), consisting of a conventional FTS followed by a grating spectrometer. By combining these two devices,we negate a substantial fraction of the sensitivity disadvantage of a conventional FTS for high-resolution, broadband, optical spectroscopy, while preserving many of the advantages inherent to interferometric spectrometers. In addition, we have implemented a simple and inexpensive laser metrology system, which enables very precise calibration ... |
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| Fiber Optic Detection of Action Potentials in Axons |
DEC 2006 |
9 pages |
| Authors:
Elisabeth Smela; MARYLAND UNIV COLLEGE PARK DEPT OF MECHANICAL ENGINEERING
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| In prior exploratory research, we had designed a fiber optic sensor utilizing a long period Bragg grating for the purpose of detecting action potentials in axons optically, through a change in index of refraction, rather than electrically. The potential application of this technology, long term, is a multi-channel interface to the peripheral nervous system in prosthetic devices. In that prior work, optical signals corresponding to electrically measured action potentials were ... |
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| Semiconductor Based Transverse Bragg Resonance (TBR) Optical Amplifiers and Laser |
NOV 2005 |
9 pages |
| Authors:
Amnon Yariv; CALIFORNIA INST OF TECH PASADENA
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| We have fabricated electrically pumped, semiconductor TBR lasers in the InP/InGaAsP material system to demonstrate the efficiency gains possible by the incorporation of a transverse Bragg grating. By incorporating a transverse Bragg grating into large-area laser, the optical modes of the laser can be designed to improve the efficiency compared to traditional index-guided lasers. The resulting transverse Bragg resonance (TBR) waveguide can be designed to have a single lateral mode ... |
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| A New Tunable Source for the FIR-THz Spectral Region |
26 JUN 2003 |
10 pages |
| Authors:
James H. Brownell; DARTMOUTH COLL HANOVER NH DEPT OF PHYSICS AND ASTRONOMY
|
| The Grating Coupled Oscillator (GCO) has the potential to be a practical coherent source for far-infrared/terahertz (FIR/THz) research and applications. The GCO, simply an electron beam skimming a diffraction grating, has inherently many desirable features: continuously tunable from microwave to visible, continuous wave at room temperature, excellent spatial and spectral quality, stable, compact, robust, simple, and economical. Alternative sources (e.g. solid-state, short-pulse optical switches, free-electron lasers, and blackbody) do not ... |
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| Formation of Profiled Holographic Diffraction Gratings Using Physicochemical Interaction in As2Se3-Ag System |
JUN 2001 |
6 pages |
| Authors:
M. V. Sopinskyy; P. F. Romanenko; I. Z. Indutnyy; E. F. Venger; UKRAINIAN ACADEMY OF SCIENCES KIEV INST OF SEMICONDUCTOR PHYSICS
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| The method of blazed holographic diffraction gratings fabrication by transformation of an original symmetric grating grooves into asymmetric ones using inclined vacuum deposition of silver and additional chemical etching have been developed. As photoresist material for gratings recording light-sensitive chalcogenide glassy As2Se3 layers were used. The shape of grating grooves was determined with an atomic force microscope. Angular and spectral dependencies of the diffraction efficiency of the gratings were found, ... |
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| Effective Holographic Record on Thin Films of Chalcogenide Semiconductors |
JUN 2001 |
6 pages |
| Authors:
V. Vlasov; UZHGOROD NATIONAL UNIV (UKRAINE)
|
| In this work is presented the research on thin films of chalcogenide glassy semiconductors as the medium for relief holograms record. The optimization of photoresist has allowed for an essential rise in sensitivity to light. As(50)Se(50) photoresist composition on which above thousandfold chemical amplification of holographic record is achieved, was used. Diffraction gratings in range of spatial frequencies 600 - 2400 mm are submitted. For natural light the magnitude of ... |
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| Evanescent - Wave Recording in Very Thin Layers |
JUN 2001 |
4 pages |
| Authors:
S. Sainov; J. Dikova; R. Stoycheva-Topalova; BULGARIAN ACADEMY OF SCIENCES SOFIA (BULGARIA) CENTRAL LAB OF PHOTOPROCESSES
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| The theoretical background of optical holographic recording in very thin films is given. The interference fringes are stored by surface - propagating evanescent waves. Such waves are created by the total internal light reflection (TIR). The experimental verification of the theory is made. The holographic grating with 454nm period has been recorded in 29, 39 and 74 nm thick As2S3 films. The diffraction efficiency dependence on the time is investigated. ... |
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| Holographic Recording in Nano-Sized As2S3 Films |
JUN 2001 |
4 pages |
| Authors:
S. Sainov; V. Sainov; J. Dikova; BULGARIAN ACADEMY OF SCIENCES SOFIA (BULGARIA) CENTRAL LAB OF PHOTOPROCESSES
|
| The diffraction gratings in 10, 15 and 2Onm thick As2S3 films are holographically recorded with a totally reflected reference wave. The maximum measured values of the diffraction efficiency are 0.0005%, 0.004% and 0.007% respectively. The exposure dependence on the diffraction efficiency is investigated. Despite of the relatively low efficiency, we succeed in the focal plane quasi-Fourier USAF test target holographic recording and reconstructed. |
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| Atomic Interference in Standing Wave Fields |
13 MAR 2001 |
|
| Authors:
Paul R. Berman; Tycho Sleator; MICHIGAN UNIV ANN ARBOR DEPT OF PHYSICS
|
| The long range goal of this project is the creation of nanostructures using light fields to manipulate atoms. To illustrate some of the theoretical progress we have made along these lines, we summarize our results on (i) a conical lens that can he used to focus atoms to a single spot, (ii) a multi- color field geometry that can be used to produce high-harmonic, sinusoidal, spatial matter gratings in a ... |
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| Enhanced Optical and Electrical Characteristics of Si Detectors Integrated with Periodic 1-D and 2-D Semiconductor Nanoscale Structures |
2001 |
7 pages |
| Authors:
A. K. Sharma; S. H. Zaidi; G. Liecthy; S. R. Brueck; AIR FORCE RESEARCH LAB KIRTLAND AFB NMSPACE VEHICLES DIRECTORATE
|
| Nanostructuring the active region of metal-silicon-metal (MSM) photodetectors (PDs) with sub-wavelength periodic 1-D and 2-D nanoscale grating structures significantly modifies the optical absorption, reflectance and transmission properties of silicon. These modifications dramatically impact the electrical characteristics of the MSM PDs. The surface reflection is reduced from ^33% (planar Si) to ^4% (nanostructured Si) for triangular shaped nanostructures. The internal quantum efficiency of the MSM PDs increased from ^63% (planar) to ... |
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| Long Gage Fiber Optic Bragg Grating Strain Sensors to Monitor Civil Structures |
2001 |
11 pages |
| Authors:
Whitten L. Schulz; Joel P. Conte; Eric Udd; BLUE ROAD RESEARCH FAIRVIEW OR
|
| Fiber optic Bragg gratings packaged in long gage configurations are being used to measure static and dynamic macro-strains in structures and structural models to monitor structural health and detect and identify macro- damage incurred from a seismic event. These long gage sensors are being used to experimentally verify analytical models of small-scale structural models in their pre- and post-damage states using system identification techniques. This fiber optic deformation measurement system ... |
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| Ion and Neutral Dynamics of Ceramic Materials Formation and Atmospheric |
27 NOV 2000 |
21 pages |
| Authors:
Veronica M. Bierbaum; Stephen R. Leone; COLORADO UNIV AT BOULDER DEPT OF CHEMISTRY
|
| An ultrafast x-ray laser system and experimental apparatus have been fully constructed, calibrated and characterized. A titanium sapphire ultrafast laser is tightly focused into a rare gas jet, where high harmonics of the laser are created. A single harmonic can be isolated with a grazing incidence grating and focused on to a gaseous sample to induce photoionization. Ejected electrons are energy analyzed using a magnetic ... |
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| Modeling and Optimal Design of Micro-Optical Structures |
31 OCT 2000 |
5 pages |
| Authors:
David C. Dobson; TEXAS A AND M UNIV COLLEGE STATION DEPT OF MATHEMATICS
|
| New methods for optimizing band structure in photonic crystals with arbitrary material configurations were developed. The methods make use of large- scale nondifferentiable optimization techniques and rely on efficient finite element solvers for computing band structures. New photonic bandgap structures with large gaps were found. New finite element methods for computing band structures in two- and three-dimensional photonic crystals were developed. These methods are specifically formulated ... |
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| THz Sources Based on Semiconductor Quantum Structures |
29 SEP 2000 |
3 pages |
| Authors:
Karl Unterrainer; J. Ulrich; R. Zobl; G. Strasser; E. Gornik; TECHNISCHE UNIV VIENNA (AUSTRIA) INST FUER FESTKOERPERELEKTRONIK
|
| We present a study on spontaneous THz emission from semiconductor quantum structures. THz emission from parabolically graded AlGaAs/GaAs quantum wells driven by an in-plane electric field has been measured. We have analyzed the grating coupled radiation in the temperature range from 20 K to 240 K. The peak emission corresponds to the intersubband plasmon in the parabolic potential. From a quantum cascade structure we observe spontaneous THz emission, based on ... |
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| Laser Micromachining of THz Components |
29 SEP 2000 |
3 pages |
| Authors:
Christian Drouet d'Aubigny; Christopher Walker; Bryan Jones; Christopher Groppi; John Papapolymerou; ARIZONA UNIV TUCSON
|
| Laser micromachining techniques can be used to fabricate high-quality waveguide and quasi-optical components to micrometer accuracies. Successful GHz waveguide designs can be directly scaled to THz frequencies. We expect this promising technology to allow the construction of the first fully integrated THz heterodyne imaging arrays. At the University of Arizona, construction of the first laser micromachining system designed for THz waveguide components fabrication has been completed. Once we have tested ... |
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| An Analytical Solution to Diffraction Problems Involving Periodically Structured Objects |
29 SEP 2000 |
3 pages |
| Authors:
Thore Magath; Mahmood Akbari; TECHNICAL UNIV HAMBURG (GERMANY) ARBEITSBEREICH HOCHFREQUENZTECHNIQ
|
| A rigorous analysis of diffraction by rectangularly profiled, dielectric gratings is presented. An analytical solu- tion is obtained for the total electromagnetic field. The approach presented can readily be extended to computa- tions for metallic gratings and arbitrarily shaped surface-relief gratings. |
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| Static and Dynamic Testing of Bridges and Highways Using Long-Gage Fiber Bragg Grating Based Strain Sensors |
2000 |
9 pages |
| Authors:
Whitten L. Schulz; Joel P. Conte; Eric Udd; John M. Seim; BLUE ROAD RESEARCH FAIRVIEW OR
|
| Fiber optic Bragg gratings packaged in long gage configurations are being used to measure static and dynamic strain in structures and structural models to monitor structural health and predict damage incurred from a seismic event. These long gage sensors are being used to experimentally verify analytical models of post-earthquake evaluation based on system identification analysis. This fiber optic deformation measurement system could play a significant role in monitoring/recording with a ... |
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| Higher Speed Demodulation of Fiber Grating Sensors |
1999 |
10 pages |
| Authors:
John Seim; Whitten L. Schulz; Eric Udd; Mike Morrell; BLUE ROAD RESEARCH FAIRVIEW OR
|
| For very high-speed events such as ballistics testing strain measurement speed is not limited by the response of the fiber grating sensor but rather the demodulation system used. This paper focuses on a current 10kHz fiber grating demodulator used to support impact and ballistics testing of a composite panel. It also explores the next generation demodulator pushing the limits of speed upwards of 3Mhz. |
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| Improved Sampled Grating DBR Widely-Tunable 1.55z Micrometer Lasers |
16 SEP 1998 |
8 pages |
| Authors:
Larry A. Coldren; Beck Mason; CALIFORNIA UNIV SANTA BARBARA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| The objective of this program is to develop a widely tunable semiconductor laser diode with an integrated wavelength monitor. During this period improvements in the device tuning range and stability have been obtained by using buried-heterostructures, and initial results with miniature, monolithic wavelength monitors have demonstrated good wavelength readout, but with some remaining problems. Techniques to solve these problems as well as alternative designs are ... |
|
| Polarization Holographic Gratings in Azopolymers for Detecting and Producing Circularly Polarized Light |
23 JUN 1998 |
6 pages |
| Authors:
P. Rochon; V. Drnoyan; A. Natansohn; QUEEN'S UNIV KINGSTON (ONTARIO) DEPT OF CHEMISTRY
|
| Polarization holographic gratings were inscribed in azobenzene side chain polymer films. The polarization gratings were produced using two orthogonally circularly polarized beams and the resulting stable transmission gratings were studied using a low power HeNe laser. The gratings were observed to efficiently separate left and right circularly polarized light from the probe beam and two generate to elliptically polarized beams in the first order diffraction direction. |
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| All Fiber-Based Optical Transmitters and Switching Technologies |
30 SEP 97 |
22 pages |
| Authors:
P. K. Cheo; E. Donkor; CONNECTICUT UNIV STORRS
|
| A coupled-cavity mode-locked fiber laser using three Bragg grating in tandem has been demonstrated. The matching of cavity lengths of the two coupled cavities is not critical and the difference in length can be as large as 2 mm still achieving mode-looking. The pulse width of these mode-locked lasers is, longer than the transform-limited value Er-doped fiber lasers are very unstable an usually exhibit self-pulsing behavior. Using a high-gain Er-doped ... |
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| Optical Fiber-Based NDI System for Aging Aircraft |
JAN 1997 |
|
| Authors:
Kent Murphy; Mark Jones; FIBER AND SENSOR TECHNOLOGIES INC BLACKSBURG VA
|
| This report describes work that has been successfully completed by the F&S team during the first year of the DARPA/Air Force sponsored program, Optical Fiber-Based ND System for Aging Aircraft Structures" contract number, F33615-95-2-5240. The purpose of this report is to provide both an overview of the current state of the strain and corrosion detection and quantification systems and future directions for continued development, testing ... |
|
| Fabry-Perot Photorefractive Quantum Well Structures for Adaptive Processing. |
NOV 1995 |
32 pages |
| Authors:
David D. Nolte; M. R. Melloch; PURDUE UNIV LAFAYETTE IN DEPT OF PHYSICS
|
| Photorefractive quantum well structures that use Fabry Perot interference effects to enhance reflected diffraction were investigated numerically and experimentally. Hybrid transmission/reflection and fully asymmetric Fabry Perot transverse field geometry and fully asymmetric Fabry Perot longitudinal field geometry devices were studied. Diffraction was significantly enhanced by the Fabry Perot resonance. The largest output diffraction efficiency of nearly 200% was achieved in a low temperature grown AlAs barrier multiple quantum well. |
|
| UV-Vis Spectrometer Assembly, Test and Calibration Guide |
SEP 95 |
55 pages |
| Authors:
Khiem Tran; Wilfred Hesketh; SPARTA INC EDWARDS AFB CA
|
| This guide contains tbe information required to assemble, characterize, calibrate and test the Phillips Laboratory Uv-Vis Spectrometer. The assembly is specific for the spectrometer; however, the characterization and calibration are more general and can be used as a guide for any spectrometer system. The guide gives direction and identifies calibration techniques that may be wed, with the test set-up and results obtained on the Phillips Laboratory instrument. The guide also ... |
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| New Developments in Atom Interferometry |
13 JUL 95 |
17 pages |
| Authors:
David Pritchard; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
|
| Atom interferometers may well be the most important development in atomic physics in the 1990's. Following the near simultaneous demonstration of four atom interferometers in 1991 (CAM9 1, KAC9 1, KET9 1, RKW9 1), intense activity has been devoted to developing better atom beamsplitters ASM94 and some effort has been devoted to applying these instruments to the wide range of fundamental and applied scientific problems for which they are so ... |
|
| Atom Wave Interferometer |
11 APR 95 |
6 pages |
| Authors:
David Pritchard; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
|
| The development of atom interferometers represents a significant advance in atomic physics. They give us the ability to measure accurately interactions that shift the phase or energy of the particles in one of the two interfering paths in the interferometer. This allows qualitatively new measurements in atomic and molecular physics and fundamental tests of quantum mechanics (especially in areas involving atom-photon interactions), and provides new ways to measure accelerations and ... |
|
| Technique to Prepare High-Reflectance Optical Fiber Bragg Gratings with Single Exposure In-Line or Fiber Draw Tower. |
21 MAR 1995 |
|
| Authors:
Charles G. Askins; Edward J. Friebele; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| A process for making an optical reflection grating in a glass fiber includes exposing all unjacketed optic fiber to a single writing pulse from a pair of interfering light beams that form an interference pattern in the fiber. A novel optical fiber has at least one optical grating with a preselected Bragg spacing in at least one region of the fiber, with a periodic modulation in its index of refraction, ... |
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| Fiber Grating-Based Sensing System with Interferometric Wavelength-Shift Detection. |
01 NOV 1994 |
|
| Authors:
Alan D. Kersey; Timothy A. Berkoff; DEPARTMENT OF THE NAVY WASHINGTON DC
|
| This patent discloses a system for sensing a measurand field, the system comprising a source of broadband light, a sensor, an unbalanced optical interferometric apparatus, and a signal processor. The sensor produces an optical return signal having a wavelength functionally dependent on the measurand field. The interferometric apparatus produces an electrical interference output signal having a phase shift functionally dependent on the wavelength of the return signal, and the processor ... |
|
| Applied Mathematical Problems in Modern Electromagnetics |
31 MAY 94 |
13 pages |
| Authors:
Gregory Kriegsman; NEW JERSEY INST OF TECH NEWARK DEPT OF MATHEMATICS
|
| Under this grant the researchers have primarily investigated two classes of electromagnetic problems. The first contains the quantitative description of microwave heating of dispersive and conductive materials. Such problems arise, for example, when biological tissue are exposed, accidentally or purposefully, to microwave radiation. Other instances occur in ceramic processing, such as sintering and microwave assisted chemical vapor infiltration and other industrial drying processes, such as the curing of paints and ... |
|
| Experimental and Theoretical Studies of Hydrogenated Amorphous Semiconductor Alloys and Superlattices |
04 FEB 94 |
132 pages |
| Authors:
Zvi S. Weisz; Manuel Gomez; PUERTO RICO UNIV RIO PIEDRAS
|
| We developed the photocarrier grating technique for carrier mobility- lifetime products (micro-Tau) measurements. Applying this technique to hydrogenated amorphous silicon (a-Si:H), we obtained micro-Tau values ranging from 10(exp-8) to 10(exp-5) sq cm/V for the majority and 10(exp-10) - 10(exp-8) for the minority carrier. This served as a basis for quality evaluation of prepared by different methods. We established that the dominant recombination mechanism is the 'defect pool' mechanism. Using the ... |
|
| Multifunctional Macromolecules |
OCT 93 |
174 pages |
| Authors:
A. J. East; M. J. Sansone; T. Findakly; HCC SCIENCE AND TECHNOLOGY CO INC SUMMIT NJ
|
| While numerous photorefractive polymers were synthesized by the incorporation of NLO chromophores and photoconductive components as side chains on a backbone, the most significant photorefractive behavior demonstration under this project was made in an electrooptic aminonitrostilbene methacrylate copolymer (P2ANS/MMA) without the addition of photoconductive compounds. By four wave mixing, photorefractive gratings were written in P2ANS/MMA using s- polarized and p-polarized writing beams and probed using orthogonally polarized probe beams. With ... |
|
| Development of Ultra-Low Noise, High Sensitivity Planar Metal Grating Coupled III-V Multiquantum Well Infrared Detectors for Focal Plane Array Staring IR Sensor Systems |
01 MAY 93 |
72 pages |
| Authors:
Shang S. Li; FLORIDA UNIV GAINESVILLE DEPT OF ELECTRICAL ENGINEERING
|
| During this reporting period we have continued to make progress towards the program goals. We have designed, fabricated, and characterized several new types of 2-D metal grating coupled n-type GaAs/AlGaAs, AlAS/AlGaAs, InAlAs/InGaAs, and InGaP/GaAs QWIPs for 2-14 micrometers focal plane arrays (FPAs) staring infrared sensor applications. In addition, a new normal incidence two-color p-type strained layer InGaAs/InA1As QWIP has been developed for the first time with highest detectivity and low ... |
|
| Design of a High Resolution Spatial Heterodyne Interferometer |
DEC 92 |
100 pages |
| Authors:
Kenneth M. Wallace Jr; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Several new spatial heterodyne interferometers were evaluated using ray tracing analysis. A spherical grating interferometer was examined and found to have nonlinear fringe patterns that are difficult to interpret. A new plane grating interferometer was designed, built and tested using a visible light laser as the source. The new design uses two mirrors and a single, planar diffraction grating to divide and recombine incident collimated light. The zero and first ... |
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| Millimeter-Wave Applications of Semiconductor Dielectric Waveguides with Plasma Layers (Surface or Buried) Generated from Semiconductor Lasers |
SEP 92 |
73 pages |
| Authors:
Jerome K. Butler; SOUTHERN METHODIST UNIV DALLAS TX
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| This research program was aimed at the theoretical and experimental investigations of semiconductor devices and waveguides with applications in millimeter wave systems. The major components considered included waveguide phase shifters, attenuators, and periodic structures designed to operate at the Second Bragg frequency. Most of the effort was directed at theoretical and experimental understanding of the second-order Bragg structures since these components produce the most efficient radiating antennas. With a goal ... |
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| A New Method for Directional LDA-Velocity Measurement of Lateral and Axial Components Using Diffraction Gratings, |
23 JUL 1992 |
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| Authors:
H. Mueller; D. Dopheide; TECHNICAL UNIV OF LISBON (PORTUGAL)
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| Using diffraction gratings as beam splitters in LDA systems the resulting fringe spacing becomes achromatic. Thus employing unstabilized laser diodes of different wavelengths, distinguishable fringe systems with identical fringe spacings int he measuring volume can be generated. The evaluation of at least two LDA burst signals and their signal phase corresponding to the different fringe systems locally parallel shifted and/or tilted against each other allows the directional measurement of lateral ... |
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| A New Laser Grating Velocimeter - Granulometer for Highly Concentrated Wet Steam Flows, |
23 JUL 1992 |
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| Authors:
A. R. Laali; A. Cartellier; P. Bauche; J. J. Courant; A. Kleitz; Ph. Martin; ELECTRICITE DE FRANCE CHATOU LAB NATIONAL D'HYDRAULIQUE
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| A new Laser Grating Velocimeter - Granulometer has been designed and manufactured for EDF applications concerning wet stream turbines. A signal processing system based on FFT technique, similar to the one used for PDPA systems, has been adapted for this probe. In this paper the technical details of design and manufacturing of the probe and its signal processing system are described. Some of the results obtained during the qualification and ... |
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GRATINGS(SPECTRA)
