| Modeling of Electron Field Emission from Graphene |
02 Dec 2011 |
3 pages |
| Authors:
Lay-Kee Ang; NANYANG TECHNOLOGICAL UNIV (SINGAPORE)
|
 | Two tasks were focused on graphene: (1) A check if traditional Fowler-Nordheim (FN) law can be used to describe field emission from single layer vertical aligned graphene. The researchers created a Klein tunneling model to show the FN law may not be valid. The results were published in APL 99, 093112 (2011). (2) It is clear that the traditional understanding or properties of the field emission is going to be ... |
|
| Suppression of Laser Shot Noise Using Laser-Cooled OptoMechanical Systems |
22 APR 2010 |
34 pages |
| Authors:
Jack G. Harris; YALE UNIV NEW HAVEN CT DEPT OF PHYSICS
|
| The goal of this effort was to create squeezed light with intensity fluctuations 15 dB below the shot noise level. This goal was to be achieved by integrating ultrasensitive MEMS inside a high finesse optical cavity at cryogenic temperatures. While we have not yet demonstrated squeezing, we have overcome what proved to be the most challenging technical hurdle: coupling laser light into a high finesse cavity containing an ultrasensitive MEMS ... |
|
| 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. ... |
|
| Next Generation, High Accuracy Optical Tracker for Target Acquisition and Cueing |
MAR 2006 |
12 pages |
| Authors:
Don S. Odell; Vlad Kogan; ASCENSION TECHNOLOGY CORP MILTON VT
|
| A critical need exists for a fast, cost-effective, six-degrees-of-freedom (6DOF) tracker that is immune to cockpit and helmet scatterers of magnetic/electrical field energy, vehicle vibration, and harsh lighting conditions. Magnetic and inertial tracking technologies each have limitations that make them undesirable as next-generation solutions. Optical tracking technologies, while having occlusion problems, are increasingly seen as the more attractive next-generation solution. The optical tracker, developed at Ascension Technology Corp to meet ... |
|
| Fermi Electronics: A Means of Correlating and Canceling Shot Noise From Solid State Devices |
08 JUN 2004 |
48 pages |
| Authors:
Elliot R. Brown; CALIFORNIA UNIV LOS ANGELES
|
| This project has developed a formalism for computing the shot noise in resonant- tunneling structures having an arbitrary number of quantum wells. It is based on the electrostatic feedback effect in quantum-well structures and is the first known shot noise formalism that treats the electrostatic and quantum effects in a self-consistent fashion. Simulation results are analyzed and compared to experimental results for an InGaAs/AlAs double-barrier structure, which is the fastest ... |
|
| Photonic Magnetic Field Sensor |
25 FEB 2002 |
7 pages |
| Authors:
Geert Wyntjes; VISIDYNE INC BURLINGTON MA
|
| Small, in-line polarization rotators or isolators to reduce feedback in fiber optic links can be the basis for excellent magnetic field sensors. Based on the giant magneto-optical (GMO) or Faraday effect in iron garnets, they with a magnetic field of a few hundred Gauss, (20 mT) for an interaction length for an optical beam of a few millimeters achieve a polarization rotation or phase shift of 45 deg (1/8 cycle). ... |
|
| Noise Analysis for Complex Field Estimation Using a Self-Referencing Interferometer Wave Front Sensor (Postprint) |
2002 |
15 pages |
| Authors:
Troy Rhoadarmer; Jeffery D. Barchers; AIR FORCE RESEARCH LAB KIRTLAND AFB NM
|
| A noise analysis tor complex field reconstruction from a self-referencing interferometer wave front sensor with an amplified reference is evaluated. The wave front sensor is constructed from a phase-shifting, point diffraction interferometer where the reference field is created by coupling a focal plane image of the input optical filed into an optical amplifier. The noise characteristics of the wave front sensor are examined in terms of the field estimations Strehl. ... |
|
| Single-Electronics |
30 APR 2001 |
24 pages |
| Authors:
James E. Lukens; Dmitri V. Averin; Konstantin K. Likharev; STATE UNIV OF NEW YORK AT STONY BROOK RESEARCH FOUNDATION
|
| This project studied both theoretically and experimentally, properties on single electron (SET) and single pair tunneling (SPT) devices. The main effort was the study of the potential application of SPT devices for quantum computation (QC). Experimentally, it was demonstrated that one type of SPT device, the Bloch Transistor (BT) could have a coherent superposition of the 0 and 1 pair state. Theoretically a number of approaches for the use of ... |
|
| Fractional Charge in Transport Through a 1D Correlated Insulator of Finite Length |
23 JUN 2000 |
2 pages |
| Authors:
V. V. Ponomarenko; STATE UNIV OF NEW YORK AT STONY BROOK DEPT OF PHYSICS AND ASTRONOMY
|
| Transport between two Fermi liquid reservoirs through a one channel wire of length L is examined when the ID electron system has an energy gap 2M: M > T(L) v(c) /L induced by the interaction in its charge mode (v(c)): charge velocity in the wire). In the spinless case transformation of reservoir electrons into solitons of fractional charge entails a crossover from a Fermi liquid regime of integer charge transfer ... |
|
| Interferometric Measurement with Squeezed Light |
03 MAR 2000 |
9 pages |
| Authors:
Hermann A. Haus; Erich P. Ippen; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
|
| The main goal of our research is the achievement of substantial squeezing of the vacuum fluctuations associated with a soliton. If the soliton is injected into the probe port of a Mach-Zehnder interferometer and the squeezed vacuum is injected into the vacuum port, sub-shot noise measurements of the phase difference between the two arms of the interferometer can be performed. The soliton squeezing is being done ... |
|
| Langevin Method for Shot Noise in Single-Electron Tunneling |
18 JUN 1999 |
4 pages |
| Authors:
A. N. Korotkov; STATE UNIV OF NEW YORK AT STONY BROOK DEPT OF PHYSICS
|
| The shot noise in correlated single-electron tunneling can be calculated using the Langevin approach. It is equivalent to the Fokker-Plank-type approach in the "orthodox" framework however the advantage is a natural possibility to describe also the fluctuations in the quantum frequency range. |
|
| Single Electronics |
MAY 1998 |
10 pages |
| Authors:
Konstantin K. Likharev; Dmitri V. Averin; James E. Lukens; STATE UNIV OF NEW YORK AT STONY BROOK
|
| During the past decade, single-electronics (for general reviews, see Ref 5. 1-3) has turned into a major field of physical and applied electronics. Preliminary studies of possible applications of single-electron devices (1,4,5) indicated that they might yield a completely new generation of both digital and analog devices with unparalleled performance. most notably extremely dense digital circuits. However, many issues before the beginning of this work these expectations have not been ... |
|
| Interferometric Measurement with Squeezed Light |
01 APR 98 |
9 pages |
| Authors:
H. A. Haus; E. P. Ippen; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
|
| The theoretical and experimental work in this reporting period was concerned with the generation and utilization of squeezed pulsed radiation. Improved sensitivity of fiber gyros with noise levels below the shot noise level is one possible utilization of such radiation. |
|
| Interferometric Measurement with Squeezed Light |
22 FEB 96 |
7 pages |
| Authors:
Hermann Haus; E. P. Ippen; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
|
| The goal of the research is to achieve interferometric phase measurements below the standard quantum limit, the shot noise limit, by using squeezed quantum states of light. The squeezing is accomplished in single mode polarizations maintaining optical fibers. Using fiber components, the light thus squeezed can be injected with minimum loss into fiber interferometers (such as a fiber gyro). |
|
| A Study of Technology for Detection of Nonluminous Artificial Satellites in Daylight. (Baitian Feizifaguang Tianti Mubiao Tance Jishu De Yanjiu) |
21 DEC 95 |
15 pages |
| Authors:
Cheng He; Qixiang Zhu; NATIONAL AIR INTELLIGENCE CENTER WRIGHT-PATTERSON AFB OH
|
| In this paper, the authors discuss the detection limits of systems for detecting nonluminous artificial satellites in daylight, as well as the relationship of target contrast and signal-to-noise ratio to artificial satellite characteristics, sky background characteristics, optical system parameters, and CCD (charge-coupled device) parameters. The authors discuss in depth the effects of spectral filtering technology on detection limits, contrast, and signal-to-noise ratio. Results of numerical simulations demonstrate that spectral filtering ... |
|
| Space Object Identification Using Spatio-Temporal Pattern Recognition |
DEC 95 |
99 pages |
| Authors:
Gary W. Brandstrom; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| This thesis is part of a research effort to automate the task of characterizing space objects or satellites based on a sequence of images. The goal is to detect space object anomalies. Two algorithms are considered - the feature space trajectory neural network (FST NN) and hidden Markov model (HMM) classifier. The FST NN was first presented by Leonard Neiberg and David P. Casasent in 1994 as a target identification ... |
|
| Coastal Water Optical Properties Prediction Development |
22 NOV 95 |
100 pages |
| Authors:
Donald Leonard; Thomas Driscoll; Paul Titterton; EOO INC SUNNYVALE CA
|
| Remote sensing concepts were evaluated for providing initial conditions to the Coastal Water Clarity predictive model. The most important water physical properties that strongly influence water optical properties are the concentrations of chlorophyll, sediment and dissolved organic matter. The currently available satellite multispectral imaging sensors do not have the required high sensitivity and small pixel size to be useful as a coastal water reconnaissance sensor. Two new satellite sensor concepts ... |
|
| Human and Community Response to Military Noise. Results From Field- Laboratory Tests of Small Arms, 25 mm Cannons, Helicopters, and Blast Sounds |
JUN 95 |
234 pages |
| Authors:
Paul D. Schomer; L. R. Wagner; L. J. Benson; CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL
|
| The study reported here utilized paired-comparison tests with listeners in real houses to evaluate human response to test sounds from one of four categories of military sources: (1) small arms fire, (2) 25 millimeter (mm) cannon fire, (3) helicopters, and (4) large blasts. The control sound sources were either a wheeled vehicle or white/pink noise. These tests, performed at Aberdeen Proving Ground, MD, compliment similar tests in Germany (Schomer et ... |
|
| Interferometric Measurement with Squeezed Light |
14 MAR 95 |
5 pages |
| Authors:
Hermann A. Haus; Karen Bergman; Luc Boivin; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
|
| The goal of the project is to develop interferometric measurement methods, using squeezed light, with noise levels below the 'standard quantum limit.' The 'standard quantum limit' is the shot noise level. If squeezed radiation is injected into the, normally, unexcited port of a Mach-Zehuder interferometer, the phase shift of the interferometer can be measured in a noise background that is below the shot noise level. In past experiments performed at ... |
|
| Analysis of Direct Detection Lightwave Systems with Optical Amplifiers |
JUN 94 |
71 pages |
| Authors:
Enver Kucukerman; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| We provide a detailed analysis of direct detection lightwave systems employing an optical preamplifier at the receiver and derive the closed form expression for the bit error probability of WDM systems employing on-off keying (OOK) as modulation format. In our analysis, we consider various cases in which the receiver model uses either a finite-time integrator or Fabry-Perot filter operating in a single channel or multi-channel environment. We take into account ... |
|
| Comparison of Coherent to Incoherent Detection at 2.09 Micrometers Using a Solid State Ladar System |
FEB 94 |
128 pages |
| Authors:
Jay A. Overbeck; WRIGHT LAB WRIGHT-PATTERSON AFB OH
|
| A 2.09 LADAR system has been built to compare coherent to incoherent detection. The 2.09 um wavelength is of interest for its high atmospheric transmission and because it is eye safe. The 2.09 um system presented within is capable of either a coherent or incoherent operational mode, is tunable in a small region around 2.09 um, and is being used to look at the statistical nature of the LADAR return ... |
|
| Wavelet Transform of Fixed Pattern Noise in Focal Plane Arrays |
FEB 94 |
28 pages |
| Authors:
Gary A. Hewer; Wei Kuo; NAVAL AIR WARFARE CENTER WEAPONS DIV CHINA LAKE CA
|
| This report summarizes research on the infrared fixed pattern noise on a microbolometer. The report demonstrates that Daubechies wavelets filter the noise in a predictable manner and presents a new approximate model for the noise, power-law shot noise. Fixed pattern noise, Fractional brownian motion, Power-law shot noise, Staring focal plane array, Wavelets. |
|
| Crosstalk Analysis of Synchronous and Asynchronous Optical Chip Interconnects with Direct Detection |
SEP 93 |
96 pages |
| Authors:
Rena M. Loesch; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis provides a crosstalk analysis of optical chip interconnects via single-mode waveguides with synchronous transmission and asynchronous transmission. This crosstalk model is general and can be used for any type of waveguide network. Three cases of laser sources will be considered: (1) each channel operates with an independent laser sources, (2) all laser sources have the same mean wavelength but with different phase noise processes, and (3) all laser ... |
|
| Interferometric Measurement with Squeezed Light |
29 JAN 93 |
5 pages |
| Authors:
Hermann A. Haus; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
|
|
| Physics and Technology of Resonant-Tunneling Devices |
20 JUL 92 |
|
| Authors:
E. R. Brown; MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB
|
 | Over the three-year course of this program, several issues in the device physics of resonant-tunneling diodes (RTDs) have been investigated, including the small-signal admittance, the shot noise, and the transport through multiple-quantum well structures. A large quantum-well inductance has been measured in the negative-differential-resistance region (NDR), but not in the positive-differential-resistance (PDR) region. The microwave shot-noise has been found to be suppressed relative to normal shot-noise in the PDR region, ... |
|
| Computation and Communication Constraints for Distributed Estimation Systems |
30 JUN 92 |
66 pages |
| Authors:
John A. Gubner; WISCONSIN UNIV-MADISON DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Research performed under this grant fall into four areas which are reflected In Published pavers: (1) J.A. Gubner, 'Random Coding for the Constrained Multiple-Access Arbitrarily Varying Channel.' Proc. Twenty-Eighth Annual Allerton Conf. Commun. Contr. Comput., Univ of Illinois, Urbana, IL, pp. 684-690, Oct. 1990. 'The Capacity Region of the Additive Multiple-Access Arbitrarily Varying Channel,' Proc. 1991 IEEE Int. Symp. Inform. Theory, Budapest, Hungary, P. 218, June 1991, . 'On the ... |
|
| Multiangle Lidar Performance in the Presence of Horizontal Inhomogeneities in Atmospheric Extinction and Scattering |
11 JUN 92 |
24 pages |
| Authors:
Dina Gutkowicz-Krusin; ELECTRO-OPTICAL SCIENCES INC IRVINGTON NY
|
| The performance of the single-ended multiangle lidar for measurements of atmospheric extinction and backscattering is analyzed in the presence of signal-induced shot noise. An algorithm for determining the transmission coefficient in the presence of horizontal inhomogeneities is described. The analysis indicates that real-time measurements of atmospheric properties with the multiangle lidar may be feasible even in inhomogeneous regions. |
|
| System Limitations for Fiber Amplifier Cascades, |
22 MAY 1992 |
|
| Authors:
Takeshi Ito; NIPPON TELEGRAPH AND TELEPHONE CORP TAKE TRANSMISSION SYSTEMS LABS
|
| The performance, of an amplifier cascade system is taken to be the product of transmission bit rate, B, and transmission distance, L. In amplifier cascade systems using the IM/DD scheme, signal spontaneous beat noise, spontaneous-spontaneous beat noise and shot noise are present in addition to receiver thermal noise, while local oscillator shot noise and local oscillator-spontaneous beat noise are additional factors in coherent systems. Signal-spontaneous and spontaneous-spontaneous beat noises generally ... |
|
| The Appropriateness of Squeezed Light for Long-Distance Communication, |
22 MAY 1992 |
|
| Authors:
Bernard Yurke; AT AND T BELL LABS MURRAY HILL NJ
|
| Squeezed light allows suitable optical systems to perform at below the standard shot-noise level. Below shot-noise performance of optical interferometers employing squeezed light has been demonstrated in the laboratory and it is clear that squeezed state enhanced microscopes and spectrometers could be constructed. There is also considerable interest in the issue of whether optical communications systems could benefit from the use of squeezed light. In fact, much of the early ... |
|
| Correlation from Randomness: Quantitative Analysis of Sputtered Graphite Surfaces Using the Scanning Tunneling Microscope |
10 MAR 92 |
62 pages |
| Authors:
E. A. Eklund; E. J. Snyder; R. S. Williams; CALIFORNIA UNIV LOS ANGELES
|
| The Scanning Tunneling Microscope (STM) was used to quantitatively examine the surface morphology of highly oriented pyrolytic graphite (HOPG) surfaces bombarded with 5 key Ar+ ions. Constant current topographs clearly showed that the morphology of the resulting nonequilibrium surfaces depended sensitively on the ion flux, the ion fluence and the sample temperature. For low and intermediate ion fluence, an increase in surface roughness with increasing ion flux was observed. For ... |
|
| Fundamental Noise Limits in Miniature Acoustic and Vibration Sensors |
31 DEC 91 |
100 pages |
| Authors:
Thomas B. Gabrielson; NAVAL AIR DEVELOPMENT CENTER WARMINSTER PA MISSION AVIONICS TECHNOLOGY DEPT
|
| Conventional noise analysis for acoustic and vibration sensors has focused either on the ambient noise floor imposed by the environment or the electrical noise floor imposed by the preamplifier. Microminiature sensors are, however, particularly sensitive to thermal (molecular) agitation because of their small moving parts. This mechanical-thermal noise can easily dominate the noise performance of these sensors. The purposes of this report are to review the fundamental noise sources in ... |
|
| Investigation of a Cesium Raman Time/Frequency Standard |
DEC 91 |
70 pages |
| Authors:
Shaoul Ezekiel; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
|
| The objective of this program was to determine the feasibility of developing an improved portable cesium clock using a semiconductor laser excited resonance Raman interaction. Such a clock has the potential to be smaller, lighter, less expensive, and more accurate than conventional cesium clocks because it does not require a microwave cavity or state selection magnets. To demonstrate this, an experimental Raman cesium clock was constructed. To excite the Raman ... |
|
| Coherent/Noncoherent Detection of Coherent Optical Heterodyne DPSK-CDMA and MFSK-CDMA Signals |
DEC 91 |
103 pages |
| Authors:
David A. Jakubek; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The system performance of a coherent optical heterodyne communication system is analyzed for MFSK-CDMA and DPSK-CDMA signalling. The analysis determines the effect that receiver thermal noise, photodetector shot noise, laser phase noise, and multiple user noise has on the system performance. For the single user system performance, the probability of bit error of the system is calculated as a function of Eb/No for laser linewidth-to-bit rate ratios from 0.1 to ... |
|
| Asynchronous Optical Sampling for Laser-Based Combustion Diagnostics in High-Pressure Flames |
17 JUN 91 |
15 pages |
| Authors:
Galen B. King; Normand M. Laurendeau; Fred E. Lytle; PURDUE UNIV LAFAYETTE IN DEPT OF CHEMISTRY
|
| This report describes the progress on the development of a new laser based combustion diagnostic for the quantitative measurement of both major and minor species in high pressure flames. The technique, asynchronous Optical Sampling (ASOPS), is a state of the art improvement in picosecond pump probe spectroscopy. A method is presented for vastly improving the output of the synchronously mode-locked dye laser systems. A pump probe absorption model is used ... |
|
| On the Bit Error Rate of Lightwave Systems with Optical Amplifiers |
JUN 1991 |
24 pages |
| Authors:
Pierre A. Humblet; Murat Azizoglu; MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR INFORMATION AND DECISION SYSTEMS
|
| We revisit the problem of evaluating the performances of communications systems with optical amplifiers and a wideband optical filter. We compute the exact probability of error and the optimal threshold and compare them with those predicted by Gaussian approximations for ASK, FSK or DPSK modulations, both for ideal photodetectors and for the case where shot noise is significant. |
|
| On Radar Receivers |
DEC 90 |
119 pages |
| Authors:
Paul E. Bishop; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| A comprehensive study of the effects of noise jamming on various pulsed radar receiver types is proposed. First, a literature review on the sources of electrical noise and various jamming waveforms is presented. The power spectra for three noise jamming waveforms are rigorously derived. These cases are shot noise in a parallel-plate diode, a series of pulses with random amplitudes and intervals, and for a series of pulses with random ... |
|
| Detection of High Altitude Aircraft Wake Vortices Using Infrared Doppler Lidar: An Assessment |
DEC 90 |
149 pages |
| Authors:
Michael J. Estes; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| This thesis investigated the feasibility of air-to-air detection of high altitude aircraft wake vortices at long ranges using infrared Doppler lidar. The purpose of this technique is to detect otherwise stealthy aircraft. Three laser wavelengths were analyzed: 1.064, 2.091, and 9.115 microns. Analysis revealed that the spectral width of the return signal from an aircraft wake presented a good signature for detection. Based on the analysis, a minimum signal-to-noise ratio ... |
|
| Signal Processing Studies of a Simulated Laser Doppler Velocimetry-Based Acoustic Sensor |
17 OCT 90 |
71 pages |
| Authors:
Martin L. Barlett; TEXAS UNIV AT AUSTIN APPLIED RESEARCH LABS
|
| In this report we discuss a possible remote acoustic sensing scheme based on laser Doppler velocimetry (LDV). The signal characteristics of an LDV signal from single particle scattering are described for differential and reference beam LDV configurations. A model is developed to simulate LDV signals which includes shot noise and random phase and additive noise contributions. Comparisons are made between results obtained from simulated and actual LDV signals using several ... |
|
| Infrared Target Detection: Signal and Noise Sensitivity Analysis |
DEC 89 |
78 pages |
| Authors:
Christopher W. Keefer; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
|
| The purpose of this thesis was to determine the effect of the statistical properties of the signal and the noise on an infrared system's detection performance. Noise sources identified and characterized include Johnson noise, shot noise, generation-recombination noise, and photon noise. The signal was characterized as either constant or fluctuating. A computer model was used to evaluate system detection performance for various combinations of signal type and noise distribution. Results ... |
|
| Frequency Division Multiplexing of Interferometric Sensor Arrays |
03 MAY 89 |
32 pages |
| Authors:
A. Dandridge; A. B. Tveten; A. M. Yurek; A. D. Kersey; E. C. McGarry; NAVAL RESEARCH LAB WASHINGTON DC
|
| This report demonstrates the multiplexing of fiber optic interferometric sensors using a CW phase generated carrier technique. The technique employs modulated diode laser sources at different carrier frequencies, near balanced interferometers (approx. 4 cm path difference) and phase generated carrier demultiplexing demodulation. This approach leads to a simple all-passive sensor array which has intrinsically low crosstalk. The system is analyzed in terms of shot noise performance and crosstalk. An experimental ... |
|
| A First Account of Long Term Stability Results Obtained on Various Cesium Standards by the Power Sensitivity Minimization Technique |
Dec-1988 |
11 pages |
| Authors:
De; Andrea Marchi; ANCONA UNIV (ITALY)
|
| In an effort to improve the long term stability of Cesium beam standards available on the market a full accuracy analysis of such devices was carried out in recent years. The outcome has been published in various papers. According to this analysis, and to measurements which have been taken to confirm it, microwave power sensitivity seems to be the most relevant parameter as far as long term stability is concerned. ... |
|
| Frequency Division Multiplexing of Interferometric Sensor Arrays |
28 SEP 88 |
|
| Authors:
A. Dandridge; A. B. Tveten; A. M. Yurek; A. D. Kersey; E. C. McGarry; NAVAL RESEARCH LAB WASHINGTON DC
|
| This report demonstrates the multiplexing of fiber optic interferometric sensors using a CW phase generated carrier technique. The technique employs modulated diode laser sources at different carrier frequencies, near balanced interferometers (about 4 cm path difference) and phase generated carrier demultiplexing demodulation. This approach leads to a simple all-passive sensor array which has intrinsically low crosstalk. The system is analyzed in terms of shot noise performance and crosstalk. An experimental ... |
|
| Series Representations of Infinitely Divisible Random Vectors and a Generalized Shot Noise in Banach Spaces |
JUL 87 |
|
| Authors:
Jan Rosinski; NORTH CAROLINA UNIV AT CHAPEL HILL DEPT OF STATISTICS
|
| A generalized shot noise in Banach spaces is defined as the a.s. limit of certain centered sums of dependent random vectors; and, a necessary and sufficient condition for its existence is given. As an immediate application, the LePage-type series representations of infinitely divisible random vectors are obtained. Keywords: Stochastic processes; Convergence; Hilbert space. |
|
| Probabilistic Methods |
16 APR 87 |
|
| Authors:
Austin J. Lemoine; Michael L. Wenocur; FORD AEROSPACE AND COMMUNICATIONS CORP PALO ALTO CA WESTERN DEVELOPMENT LABS DIV
|
| Research was performed in several means of probabilistic methods, Primary results include representations of equilibrium Sojourn time distribution in Jackson networks, of queues. Other results develops new practical and theoretical results in computing first passage time statistics. Promising results for developing a method for inverting large sparse motives were obtained. The scientific objectives of this research program are to develop improved probabilistic and statistical methods and to demonstrate their power ... |
|
| Fiber-Optic Accelerometer Investigation |
87 |
|
| Authors:
Waldemar Zukauskas; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| A fiber-optic accelerometer concept based on the radial displacement of a hollow cylinder subject to acceleration is experimentally investigated. The accelerometer configuration consists of two PZT cylinders wrapped with 2.3 meters of high birefringent single mode fiber placed in a differential configuration. Cylinder radial displacement induces an axial strain into the fiber which stretches the fiber, causing a simultaneous optical path length and index of refraction change. The result is ... |
|
| Nonlinearity and Single Shot Noise Problems in CARS (Coherent Antistokes Raman Scattering) Spectroscopy, |
NOV 1986 |
|
| Authors:
D. R. Snelling; G. J. Smallwood; R. A. Sawchuk; T. Parameswaran; DEFENCE RESEARCH ESTABLISHMENT OTTAWA (ONTARIO)
|
| This paper describes the design and operation of a CARS spectrometer and its use to perform accurate temperature measurements in a simple laboratory flat-flame burner. Instrumental sources of systematic error and noise in CARS temperature measurements are discussed. An analysis of the system noise is presented and the use of the measured noise to perform weighted least mean squares fits of experimental and theoretical CARS spectra is discussed. The use ... |
|
| Exploration of the Potential Performance of Diode Laser-Pumped Gas Cell Atomic Frequency Standards |
30 SEP 86 |
|
| Authors:
James C. Camparo; Robert P. Frueholz; AEROSPACE CORP EL SEGUNDO CA CHEMISTRY AND PHYSICS LAB
|
| Recently, there has been considerable interest in the use of single- mode diode lasers in atomic frequency standards. In this report, theoretical calculations were performed to quantify the expected performance improvement upon incorporation of diode lasers in rubidium gas cell atomic frequency standards. We assume that clock signal shot noise, the diode laser's quantum noise, and diode laser frequency locking noise all contribute to the atomic frequency standard's stability. Keywords ... |
|
| MicroBNOISE: A User's Manual |
JUN 86 |
96 pages |
| Authors:
Steven D. Hottman; John J. Fittipaldi; Richard G. Gauthier; Mark E. Cole; CONSTRUCTION ENGINEERING RESEARCH LAB (ARMY) CHAMPAIGN IL
|
| The Army has developed the Installation Compatible Use Zone(ICUZ) program to safeguard the operational capability of Army installations from encroachment by off-post, noise-sensitive land uses such as housing. ICUZ, which is based on the Integrated Noise Contour System developed by the U.S. Army Construction Engineering Research Laboratory(USA-CERL), requires noise contours to be developed around military installations to assist in effective land-use planning and to prevent community encroachment on high-noise training ... |
|
| Calculation of Cumulative Distributions and Detection Probabilities in Communications and Optics |
31 MAR 86 |
|
| Authors:
Carl W. Helstrom; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCES
|
| This report treats the numerical computation of cumulative distributions of random variables occurring primarily in communications, radar, and optics when their moment-generating or probability-generating functions are known. The cumulative distribution of a continuous random variable is expressed as a Laplace inversion integral of its moment-generating function, that of an integer-valued random variable as a contour integral that arises from Cauchy's theorem and whose integrand involves the probability-generating function. These integrals ... |
|
| Basic and Applied Research in the Field of Electronics and Communications |
19 MAR 86 |
|
| Authors:
Jonathan Allen; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
|
| During this period, considerable progress was made on experimental and theoretical designs for optical waveguide switches, multiplexors, and demultiplexors that can operate at a rate of 20 gigahertz, centered around the waveguide Mach-Zehnder interferometer. Extensive investigations into device applications of coupled waveguide structures have led to the ability to inject power into one of n input waveguide ports, and deliver power from any selected port using these techniques. Basic logic ... |
|
Reports by Keyword(s)
SHOT NOISE
