In optical communication networks, an intensity fluctuation of optical signals is a serious issue, which is caused by and grows owing to transmission, amplification, and signal processing. Because it degrades the sign...
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In optical communication networks, an intensity fluctuation of optical signals is a serious issue, which is caused by and grows owing to transmission, amplification, and signal processing. Because it degrades the signal-to-noise ratio (SNR) of optical signals and eventually leads to inaccuracy of data, the intensity fluctuation of optical signals over optical communication networks must be compensated for. In order to compensate for the intensity fluctuation of optical pulses with a wide dynamic range, in this paper, we propose an ultrafast all-optical intensity stabilizer based on an intensity-dependent spectral pattern change and an optical pattern recognition. To verify the proposed method, we perform numerical simulations and experimental demonstrations. We confirm the basic operation of the optical intensity stabilizer through experimental demonstrations. [DOI: 10.1143/JJAP.47.8834]
To cope with a larger intensity fluctuation of optical signals in optical communication networks, we have proposed and demonstrated an ultra-fast all-optical intensity equalizer based on an optical pattern recognition...
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To cope with a larger intensity fluctuation of optical signals in optical communication networks, we have proposed and demonstrated an ultra-fast all-optical intensity equalizer based on an optical pattern recognition technique. To achieve higher transfer efficiency for this equalizer, we designed and fabricated a highly-efficient optical amplitude-phase filter using a diffractive optical element for optical pattern recognition. The fabricated amplitude-phase filter provides a diffraction efficiency of 85%, and the all-optical intensity equalizer is demonstrated to have higher transfer efficiency, when this filter is used.
This paper discusses a method of increasing the memory of an optical correlator through the use of matched filter arrays. The matched filters are sequentially addressed using an acousto-optic beam deflector.
This paper discusses a method of increasing the memory of an optical correlator through the use of matched filter arrays. The matched filters are sequentially addressed using an acousto-optic beam deflector.
The design of real-valued composite filters for optical pattern recognition and classification is considered. A procedure to design a real-valued minimum average correlation energy (MACE) filter is developed. Also, th...
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ISBN:
(纸本)0819409456
The design of real-valued composite filters for optical pattern recognition and classification is considered. A procedure to design a real-valued minimum average correlation energy (MACE) filter is developed. Also, the design of a real MVSDF-MACE filter that minimizes the output variance due to input noise while maintaining a sharp correlation peak is developed. Computer simulation indicates that the performance of these real filters is almost as good as that of the complex filters.
Spatial coherence in optical processing can be exploited to implement a wide variety of image processing functions. While fully coherent systems tend to receive the most attention, spatially noncoherent systems can of...
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ISBN:
(纸本)0819415413
Spatial coherence in optical processing can be exploited to implement a wide variety of image processing functions. While fully coherent systems tend to receive the most attention, spatially noncoherent systems can often provide equivalent functionality while offering significant advantages over coherent systems with regard to noise performance and system robustness. The term noncoherent includes both partially coherent and fully incoherent illumination. In addition to the noise immunity advantage, noncoherent diffraction-based processors have relaxed requirements on pupil plane spatial light modulator characteristics. In this paper we provide a discussion of the tradeoffs between coherent and noncoherent processing, taking into account the limited performance characteristics of commercially available spatial light modulators. The advantages of noncoherent processing are illustrated with numerical and experimental results corresponding to three different noncoherent architectures.
The optical Processor Enhanced Ladar (OPEL) program is designed to evaluate the capabilities of a seeker obtained by integrating two state-of-the-art technologies, laser radar, or ladar, and optical correlation. The p...
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ISBN:
(纸本)0819428353
The optical Processor Enhanced Ladar (OPEL) program is designed to evaluate the capabilities of a seeker obtained by integrating two state-of-the-art technologies, laser radar, or ladar, and optical correlation. The program is a thirty-two month effort to build, optimize, and test a breadboard seeker system (the OPEL System) that incorporates these two promising technologies. Laser radars produce both range and intensity image information. Use of this information in an optical correlator is described. A correlator with binary phase input and ternary amplitude and phase filter capability is assumed. Laser radar imagery was collected on five targets over 360 degrees of azimuth from 3 elevation angles. This imagery was then processed to provide training sets in preparation for filter construction. This paper reviews the ladar and optical correlator technologies used, outlines the OPEL program, and describes the OPEL system.
With excellent physical properties the photorefractive crystals, such as BSO (Bi(12)SiO(20)), BaTiO(3) and GaAs materials, have, can be widely used in optical correlator to implement auto patternrecognition. As the b...
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ISBN:
(纸本)9780819481603
With excellent physical properties the photorefractive crystals, such as BSO (Bi(12)SiO(20)), BaTiO(3) and GaAs materials, have, can be widely used in optical correlator to implement auto patternrecognition. As the basic devices in optical correlator, the properties of optically-addressed spatial light modulator are very important. By analyzing the dynamic process of the BSO spatial light modulator, especially the changes of the read-out light while in writing under various operation modes, the distinctness between various operation modes is summarize. Furthermore, considered with the photo-induced current pulses, the method to optimize the BSO spatial light modulator is proposed. The BSO spatial light modulator working in optimum operation mode is used to design a optical correlator to implement auto patternrecognition.
optical correlation for patternrecognition with selective and adjustable discrimination capability is based on the Dual Nonlinear Correlation (DNC) algorithm and on a two-step Joint Transform Correlator (JTC) archite...
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ISBN:
(纸本)081944149X
optical correlation for patternrecognition with selective and adjustable discrimination capability is based on the Dual Nonlinear Correlation (DNC) algorithm and on a two-step Joint Transform Correlator (JTC) architecture. The DNC encompasses nonlinear power-law processing operating independently on the spectra of the input image and the reference target. But the eventual capabilities of the system strongly depend on some experimental conditions such as quantization, gray-level dynamic range, saturation and other technical characteristics of both the camera and the spatial light modulator used in the JTC. In this work we explore these capabilities for three available modulators (Epson and two different CRLs) acting in both the input and the modified joint power spectra planes for the first and second steps of the JTC, respectively.
An implementation of a phase extractor Vander-Lugt correlator, which operates with a single spatial light modulator is suggested. optical phase-retrieval manipulation, based on the symmetrization of the input scenes i...
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ISBN:
(纸本)0819416215
An implementation of a phase extractor Vander-Lugt correlator, which operates with a single spatial light modulator is suggested. optical phase-retrieval manipulation, based on the symmetrization of the input scenes is proposed. As a consequence, the number of digital manipulations of the information is substantially reduced and spatial correlation filters can be used. Theoretical analysis and some simulated results are provided. The study also includes the results when the scenes are immersed into background or zero mean additive noise.
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