Results 241 to 250 of about 2,975,863 (286)
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A large-aperture high-extinction-ratio Faraday-rotator isolator
IEEE Journal of Quantum Electronics, 1973A 45° Faraday rotator has been built at the Naval Research Laboratory. This rotator is designed for use with a short-pulse high-peak-power laser, and it has demonstrated an extinction ratio in excess of 35 dB.
O. Barr, J. McMahon, J. Trenholme
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Imaging signal-to-noise ratio of synthetic aperture ladar
SPIE Proceedings, 2015On the basis of the Poisson photocurrent statistics in the photon-limited heterodyne detection, in this paper, the signal-to-noise ratios in the receiver in the time domain and on the focused 1-D image and 2-D image in the space domain are derived for both the down-looking and side-looking synthetic aperture imaging ladars using PIN or APD photodiodes.
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Electrode structure for high transmittance and aperture ratio in TFT-LCD
Journal of Materials Processing Technology, 2007Abstract In this paper, we propose a new cell structure having a high aperture ratio and transmittance with chevron-shaped electrode. As an exemplary cell, we selected patterned vertical alignment (PVA) mode. Optical transmittance and aperture ratio were calculated by 3D-FEM numerical solver and extended Jones method solver.
Sukin Yoon, Taeyoung Won
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Method for measuring the area of radiometric apertures using the ratio of Gaussian beams
Applied Optics, 2017I propose and demonstrate a method for determining the area of radiometric apertures using the power ratio between Gaussian beams. The result relies on measuring the power of an optical beam of known radius with and without the radiometric aperture, this with area smaller than the beam spot.
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Estimator and signal-to-noise ratio for an integrative synthetic aperture imaging technique
Applied Optics, 1991An imaging system is described which uses the following concepts: laser illumination of objects, nonredundant apertures, and phase closure. A sparse transmitter array is envisioned, each aperture of which emits at a different laser frequency such that any pair of beams gives rise to a unique beat signal. The light reflected by an object thus irradiated
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Time Lens with Improved Aperture to Resolution Ratio Based on a Phase Modulator
2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring), 2019A time lens with improved aperture to resolution ratio is proposed, which is composed of a series of splitted quadrature phase, realized by using a phase modulator with low half-wave voltage and a splitted parabolic driving signal. By splitting the standard parabolic driving signal into $2N$ pieces within the same time aperture, the temporal ...
Bowen Zhang +3 more
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Thermal emission from periodic array of microcavities with a different aperture ratio
Summaries of Papers Presented at the Quantum Electronics and Laser Science Conference, 2003Summary form only given. Recent studies of thermal emission control have revealed many interesting phenomena. The influence of microstructures upon thermal emission, however, has not well been understood. In this paper, we report experimental results of thermal emission from a tantalum surface having a periodic array of microcavities.
F. Kusunoki, J. Takahara, T. Kobayashi
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On the optimisation of distributed ambiguity ratio and directivity for a synthetic aperture radar
26th European Microwave Conference, 1996, 1996Space borne Synthetic Aperture Radar (SAR) is a radar capable of high resolution imaging of the surface of the earth. Typical applications of a space borne SAR include the observation of oil slicks, ice packs, shipping lanes, industrial pollution and agricultural usage. The SAR spacecraft travels in a low earth orbit focusing a narrow radiation pattern
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The Analysis for OLED property of the devices with various aperture ratio by Impedance Spectroscopy
2018 IEEE 2nd Electron Devices Technology and Manufacturing Conference (EDTM), 2018We investigated the OLED device property with changing the aperture ratio of the device. From VIL and the impedance spectroscopy (IS) measurement, it is considered that the efficiency is influenced by the lateral leakage in the device of the less aperture ratio.
Tomohiko Naganuma +4 more
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On the signal-to-noise ratio of a synthetic aperture ultrasound imaging method
European Journal of Ultrasound, 1996Abstract Conventional synthetic aperture ultrasound imaging requires wide angular response of the probe which presumes the use of a narrow transducer element. As a result the signal-to-noise ratio and the contrast resolution become poor. The problem can be overcome by using a multielement subarray and making the beam narrower.
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