» View Full Text: Acrobat PDF (113 KB) * * Note that full-text PDFs from conferences typically co... more » View Full Text: Acrobat PDF (113 KB) * * Note that full-text PDFs from conferences typically contain 1-3 pages of content, some or all of which might be an abstract, summary, or miscellaneous items. ... Design of graded index refractive element that induces phase retardation on two ...
Micro (MEMS) and Nanotechnologies for Defense and Security, 2007
ABSTRACT In this paper, the fabrication, modeling and characterization of an all optically addres... more ABSTRACT In this paper, the fabrication, modeling and characterization of an all optically addressed spring patterned silicon-nitride deformable mirror Micro-Electro-Mechanical-System (MEMS) device is reported. This device is biased through combinations of high frequency AC and DC voltages. The experimentally verified theoretical modeling for this device shows mirror deflection saturation as a function of light intensity appropriate for dynamic range compression deconvolution. It was experimentally verified that the spring MEMS deformable mirror device has response up to 10 MHz, which opens the possibility of correcting supersonic turbulence as well as atmospheric turbulence.
Micro (MEMS) and Nanotechnologies for Defense and Security, 2007
We propose dynamic range compression deconvolution by a new nonlinear optical limiter micro-elect... more We propose dynamic range compression deconvolution by a new nonlinear optical limiter micro-electro-mechanical system (NOLMEMS) device. The NOLMEMS uses aperturized, reflected coherent light from optically addressed, parabolically deformable mirrors. The light is collimated by an array of micro-lenses. The reflected light saturates as a function of optical drive intensity. In this scheme, a joint image of the blurred input information and the blur impulse response is captured and sent to a spatial light modulator (SLM). The joint information on the SLM is read through a laser beam and is Fourier transformed by a lens to the back of the NOLMEMS device. The output from the NOLMEMS is Fourier transformed to produce the restored image. We derived the input-output nonlinear transfer function of our NOLMEMS device, which relates the transmitted light from the pinhole to the light intensity incident on the back side of the device, and exhibits saturation. We also analyzed the deconvolution orders for this device, using a nonlinear transform method. Computer simulation of image deconvolution by the NOLMEMS device is also presented.
We propose and demonstrate a photorefractive real-time holographic deconvolution technique for ad... more We propose and demonstrate a photorefractive real-time holographic deconvolution technique for adaptive one-way image transmission through aberrating media. In contrast with preceding methods, which have typically required various coding of the exact phase or two way image transmission for correcting phase distortion, our technique relies on one-way image transmission through using exact phase information. Our technique can simultaneously correct both amplitude and phase distortions and provide substantial noise filtering. The nonlinearity of the photorefractive medium also helps to enhance the signal-to-noise ratio (SNR). And is thus superior to previous methods. We demonstrate our results through both experiment and computer simulation for different aberrators.
We propose and demonstrate a photorefractive real-time holographic deconvolution technique for ad... more We propose and demonstrate a photorefractive real-time holographic deconvolution technique for adaptive one-way image transmission through aberrating media. In contrast with preceding methods, which have typically required various coding of the exact phase or two-way ...
A new, optically addressed deformable mirror device is demonstrated. The device consists of a pix... more A new, optically addressed deformable mirror device is demonstrated. The device consists of a pixellated metalized polymeric membrane mirror supported above an optically addressed photoconductive substrate. A conductive transparent ZnO layer is deposited on the back side of the substrate. A very high-frequency AC bias is applied between the membrane and the back electrode of the device. The membrane is deformed when the back of the device is illuminated because of impedance and bias redistribution between two cascaded impedances. We fabricated, demonstrated, and modeled the operation of this device.
We introduce a dynamic range image compression technique for nonlinear deconvolution; the impulse... more We introduce a dynamic range image compression technique for nonlinear deconvolution; the impulse response of the distortion function and the noisy distorted image are jointly transformed to pump a clean reference beam in a two-beam coupling arrangement. The Fourier transform of the pumped reference beam contains the deconvolved image and its conjugate. In contrast to standard deconvolution approaches, for which noise can be a limiting factor in the performance, this approach allows the retrieval of distorted signals embedded in a very high-noise environment.
We have developed a spatial demultiplexing/multiplexing algorithm for correcting sinusoidally sca... more We have developed a spatial demultiplexing/multiplexing algorithm for correcting sinusoidally scanned distorted images. In our approach, the scanned image is demultiplexed into equal spatial slots (strips) perpendicular to the scan direction. Each spatial slot is interpolated through ...
... stants of ~l/60 s had been used. Acknowledgements The authors are grateful to S. Sawan and YT... more ... stants of ~l/60 s had been used. Acknowledgements The authors are grateful to S. Sawan and YT Shieh for the use of their equipment and for helpful discus-sions and to R. Holmstrom and J. Lavine for their com-ments on the paper. ... Sengupta and S. К. Tripathy: J. Appi. Phys. ...
We propose the design of an optical limiter based on a microelectromechanical systems deformable ... more We propose the design of an optical limiter based on a microelectromechanical systems deformable mirror. The design is based on aperturing focused light reflected out of an optically driven deformable mirror, deformed in a parabolic form. We derive an expression ...
» View Full Text: Acrobat PDF (94 KB) * * Note that full-text PDFs from conferences typically con... more » View Full Text: Acrobat PDF (94 KB) * * Note that full-text PDFs from conferences typically contain 1-3 pages of content, some or all of which might be an abstract, summary, or miscellaneous items. ... In this paper a generic nonlinear dynamic range compression deconvolver ...
» View Full Text: Acrobat PDF (113 KB) * * Note that full-text PDFs from conferences typically co... more » View Full Text: Acrobat PDF (113 KB) * * Note that full-text PDFs from conferences typically contain 1-3 pages of content, some or all of which might be an abstract, summary, or miscellaneous items. ... Design of graded index refractive element that induces phase retardation on two ...
Micro (MEMS) and Nanotechnologies for Defense and Security, 2007
ABSTRACT In this paper, the fabrication, modeling and characterization of an all optically addres... more ABSTRACT In this paper, the fabrication, modeling and characterization of an all optically addressed spring patterned silicon-nitride deformable mirror Micro-Electro-Mechanical-System (MEMS) device is reported. This device is biased through combinations of high frequency AC and DC voltages. The experimentally verified theoretical modeling for this device shows mirror deflection saturation as a function of light intensity appropriate for dynamic range compression deconvolution. It was experimentally verified that the spring MEMS deformable mirror device has response up to 10 MHz, which opens the possibility of correcting supersonic turbulence as well as atmospheric turbulence.
Micro (MEMS) and Nanotechnologies for Defense and Security, 2007
We propose dynamic range compression deconvolution by a new nonlinear optical limiter micro-elect... more We propose dynamic range compression deconvolution by a new nonlinear optical limiter micro-electro-mechanical system (NOLMEMS) device. The NOLMEMS uses aperturized, reflected coherent light from optically addressed, parabolically deformable mirrors. The light is collimated by an array of micro-lenses. The reflected light saturates as a function of optical drive intensity. In this scheme, a joint image of the blurred input information and the blur impulse response is captured and sent to a spatial light modulator (SLM). The joint information on the SLM is read through a laser beam and is Fourier transformed by a lens to the back of the NOLMEMS device. The output from the NOLMEMS is Fourier transformed to produce the restored image. We derived the input-output nonlinear transfer function of our NOLMEMS device, which relates the transmitted light from the pinhole to the light intensity incident on the back side of the device, and exhibits saturation. We also analyzed the deconvolution orders for this device, using a nonlinear transform method. Computer simulation of image deconvolution by the NOLMEMS device is also presented.
We propose and demonstrate a photorefractive real-time holographic deconvolution technique for ad... more We propose and demonstrate a photorefractive real-time holographic deconvolution technique for adaptive one-way image transmission through aberrating media. In contrast with preceding methods, which have typically required various coding of the exact phase or two way image transmission for correcting phase distortion, our technique relies on one-way image transmission through using exact phase information. Our technique can simultaneously correct both amplitude and phase distortions and provide substantial noise filtering. The nonlinearity of the photorefractive medium also helps to enhance the signal-to-noise ratio (SNR). And is thus superior to previous methods. We demonstrate our results through both experiment and computer simulation for different aberrators.
We propose and demonstrate a photorefractive real-time holographic deconvolution technique for ad... more We propose and demonstrate a photorefractive real-time holographic deconvolution technique for adaptive one-way image transmission through aberrating media. In contrast with preceding methods, which have typically required various coding of the exact phase or two-way ...
A new, optically addressed deformable mirror device is demonstrated. The device consists of a pix... more A new, optically addressed deformable mirror device is demonstrated. The device consists of a pixellated metalized polymeric membrane mirror supported above an optically addressed photoconductive substrate. A conductive transparent ZnO layer is deposited on the back side of the substrate. A very high-frequency AC bias is applied between the membrane and the back electrode of the device. The membrane is deformed when the back of the device is illuminated because of impedance and bias redistribution between two cascaded impedances. We fabricated, demonstrated, and modeled the operation of this device.
We introduce a dynamic range image compression technique for nonlinear deconvolution; the impulse... more We introduce a dynamic range image compression technique for nonlinear deconvolution; the impulse response of the distortion function and the noisy distorted image are jointly transformed to pump a clean reference beam in a two-beam coupling arrangement. The Fourier transform of the pumped reference beam contains the deconvolved image and its conjugate. In contrast to standard deconvolution approaches, for which noise can be a limiting factor in the performance, this approach allows the retrieval of distorted signals embedded in a very high-noise environment.
We have developed a spatial demultiplexing/multiplexing algorithm for correcting sinusoidally sca... more We have developed a spatial demultiplexing/multiplexing algorithm for correcting sinusoidally scanned distorted images. In our approach, the scanned image is demultiplexed into equal spatial slots (strips) perpendicular to the scan direction. Each spatial slot is interpolated through ...
... stants of ~l/60 s had been used. Acknowledgements The authors are grateful to S. Sawan and YT... more ... stants of ~l/60 s had been used. Acknowledgements The authors are grateful to S. Sawan and YT Shieh for the use of their equipment and for helpful discus-sions and to R. Holmstrom and J. Lavine for their com-ments on the paper. ... Sengupta and S. К. Tripathy: J. Appi. Phys. ...
We propose the design of an optical limiter based on a microelectromechanical systems deformable ... more We propose the design of an optical limiter based on a microelectromechanical systems deformable mirror. The design is based on aperturing focused light reflected out of an optically driven deformable mirror, deformed in a parabolic form. We derive an expression ...
» View Full Text: Acrobat PDF (94 KB) * * Note that full-text PDFs from conferences typically con... more » View Full Text: Acrobat PDF (94 KB) * * Note that full-text PDFs from conferences typically contain 1-3 pages of content, some or all of which might be an abstract, summary, or miscellaneous items. ... In this paper a generic nonlinear dynamic range compression deconvolver ...
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