We have applied the interference fringe scanning algorithms that are used in interference fringe analysis to an optical encoder as angle detection algorithms, in order to disperse the influence of sinusoid wave distor...
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ISBN:
(纸本)0819437581
We have applied the interference fringe scanning algorithms that are used in interference fringe analysis to an optical encoder as angle detection algorithms, in order to disperse the influence of sinusoid wave distortion from the encoder's photo detector. We also evaluated these algorithms with the analytical system and techniques for obtaining the same output signal as that of the actual encoder, by using image data on light intensity as the light permeates the slit disk of the encoder. As a result, we obtained about twice the angle precision by applying the algorithms to the optical encoder.
The scope of this work is the compensation of the chromatic dispersion inherent to free-space Light propagation, both in the Fraunhofer and in the Fresnel diffraction region. The cornerstone of our procedure Lies in a...
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ISBN:
(纸本)0819437581
The scope of this work is the compensation of the chromatic dispersion inherent to free-space Light propagation, both in the Fraunhofer and in the Fresnel diffraction region. The cornerstone of our procedure Lies in achieving, in a first-order approximation, the incoherent superposition of the monochromatic versions of the selected diffraction pattern in a single plane and with the same scale for all the wavelengths of the incident light. Our novel optical configurations with achromatic properties for the field diffracted by a screen are formed by a proper combination of a small number of conventional diffractive and refractive lenses, providing an achromatic real image of the diffraction pattern of interest. The residual chromatic aberrations in every case are low even when the spectrum of the incident Light spreads over the whole visible region. The resulting achromatic hybrid (diffractive-refractive) systems are applied, in a second stage, for implementing several achromatic diffraction-based applications with white light, like wavelength-independent spatial-frequency filtering, achromatic pattern recognition, white-light array generation, and to designing a totally-incoherent optical processor that is able to perform color processing operations under natural illumination (both spatially and temporally incoherent).
Free-space interconnections for optical computing and informationprocessing require an understanding of the three dimensional propagation of ultrahigh bandwidth optical pulses. Unlike optical fibers that are basicall...
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ISBN:
(纸本)081943759X
Free-space interconnections for optical computing and informationprocessing require an understanding of the three dimensional propagation of ultrahigh bandwidth optical pulses. Unlike optical fibers that are basically waveguides, free space propagation involves additional phenomenon such as self-focusing. In order to understand the properties of unguided or free space propagation for interconnections it is necessary to use a three dimensional spatial grid as well as the usual temporal grid. We derived an expression for the propagation of free space optical pulses for data rates on the order of hundreds of terabits/sec. Our formulation incorporates physical parameters such as the pulse duration, pulse intensity and free space characteristics. Numerical calculations show the spatiotemporal pulse distortion for free space propagation.
This paper addresses the issue of objectively measuring the performance of pixel level image fusion systems. The proposed fusion performance metric models the accuracy with which visual information is transferred from...
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ISBN:
(纸本)0819436771
This paper addresses the issue of objectively measuring the performance of pixel level image fusion systems. The proposed fusion performance metric models the accuracy with which visual information is transferred from the input images to the fused image. Experimental results clearly indicate that the metric is perceptually meaningful.
This Volume 4513 of the conference proceedings contains 29 papers. Topics discussed include fiber optical sensors and networks, opticalprocessing methods and systems for fiber optic sensors and measuring networks.
This Volume 4513 of the conference proceedings contains 29 papers. Topics discussed include fiber optical sensors and networks, opticalprocessing methods and systems for fiber optic sensors and measuring networks.
Recent developments in the area of micromachining and mircofabrication are accelerating commercial awareness of microstructures. Product applications ranging from automotive and medical devices to industrial, chemical...
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ISBN:
(纸本)0819438340
Recent developments in the area of micromachining and mircofabrication are accelerating commercial awareness of microstructures. Product applications ranging from automotive and medical devices to industrial, chemical and consumer products show the necessity of adequate fabrication methods for microstructures. These fabrication methods include high resolution measurement technologies. Images of the machined area, recorded via videography by a CCD-camera based computer vision system are evaluated to obtain the two dimensions (x and y) of the microstructured devices. Height measurement (z) is performed by automatically focussing on two different levels of the workpiece. The achieved accuracy of the measurement data is evaluated. During structuring of microdevices an autofocus system is used to control the removal process by laser radiation to obtain the desired geometry. The mathematical algorithms used by the vision system to guide the focus of the CCD-camera are discussed. The designed measurement system is tested by microstructuring of hard metals and ceramics with short pulse (ns, ps) laser radiation.
The paper describes the design concept of an optoelectronic system for real time image motion analysis. The system is proposed to be used onboard an Earth observation satellite for the real time recording of the image...
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ISBN:
(纸本)0819437581
The paper describes the design concept of an optoelectronic system for real time image motion analysis. The system is proposed to be used onboard an Earth observation satellite for the real time recording of the image motion in the focal plane of the camera. With this record available, it is possible to use pushbroom scan cameras onboard satellites with moderate attitude stability (possible geometric distortions, caused by the attitude instability, can be corrected posteriori on base of the records). New experimental results are presented, which have been derived from a real-time breadboard model of the optical processor, developed and manufactured under ESA-contract. The results of the tests are provided as well as the expected performances of a full scale system.
Spatial solitons in cavities are investigated with a view to applications in parallel informationprocessing. The nature, experimental demonstration, and control of spatial solitons in cavities are discussed. Properti...
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Spatial solitons in cavities are investigated with a view to applications in parallel informationprocessing. The nature, experimental demonstration, and control of spatial solitons in cavities are discussed. Properties of interest for informationprocessing are identified.
The demand for higher data capacity and reduced levels of interference in the communications arena are driving data links toward higher carrier frequencies and wider modulation bandwidths. Circuitry for performing int...
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ISBN:
(纸本)0819437573
The demand for higher data capacity and reduced levels of interference in the communications arena are driving data links toward higher carrier frequencies and wider modulation bandwidths. Circuitry for performing intermediate frequency processing over these more demanding ranges is needed to provide complex signal processing. We have demonstrated photonics technologies utilizing Bragg Grating Signal processing (BGSP), which can be used to perform a variety of RF filter functions. The desirable benefits of multiple-tap adaptive finite impulse response (FIX) filters, infinite impulse response (IIR) filters, and equalizers are well known;however, they are usually the province of digital signal processing and demand preprocessor sample rates that require high system power consumption. BGSPs provide these functions with discrete optical taps and digital controls while only requiring bandwidths easily provided by conventional RF circuitry. This is because the actual signal processing of the large information bandwidths is performed in the optical regime, while control functions are performed at RF frequencies compatible with integrated circuit technologies. To realize the performance benefits of photonic processing, the Bragg grating reflectors must be stabilized against environmental without unduly taxing the RF control circuitry. We have implemented a orthogonally coded tap modulation technique which stabilizes the transfer function of the signal processor and enables significant adaptive IF signal processing to be obtained with very low size, weight, and power. Our demonstration of a photonic proof-of-concept architecture is a reconfigurable, multiple-tap FIR filter that is dynamically controlled to implement low-pass, high-pass, band-pass, band-stop, and tunable filters operating over bandwidths of 3 GHz.
A program model and relative software tool has been developed allowing to simulate transformations of different physical nature the initial image undergo while passing through electro-optical path of TR TDI system. Th...
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ISBN:
(纸本)0819440264
A program model and relative software tool has been developed allowing to simulate transformations of different physical nature the initial image undergo while passing through electro-optical path of TR TDI system. The program consists of appropriate successively processed units, considering influence of atmosphere, optics, scanning, photodetector (PD) and multiplexer, on initial thermal image. The developed software is intended to be an everyday-practice focal plane arrays (FPAs) engineer's tool for optimizing PD and multiplexer structure and tradeoff analysis. In addition, the software was developed as a first part of more general program now under design, which allows one to estimate an effectiveness of different methods and algorithms of image reconstruction from TDI -"rows" output data. The software is especially useful in the cases of relatively complex arrangement of photodetector apertures, and/or when image motion trajectory in the focal plane is "non-ideal" (e.g., skewed with respect to its normal direction, or waved-form), which are the cases in practical systems. The main features of the designed model are described and some advantages of the program are discussed. The preliminary results on the image processing in practical middle-wave infrared (MWIR) TDI system are given demonstrating the influence of various system parameters on final image quality and confirming the validity of the model.
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