Arash Karbaschi

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We investigate the feasibility of designing spectral diversity filters using spherical beam volume holograms. Our experimental results qualitatively show the separation of the information of different incident wavelength channels using spherical beam volume holograms. The major trade-off in using these holograms is between the degree of spatial spectral(More)
We present experimental demonstrations of spectral diversity filters with spherical beam volume holograms for multimodal multiplex spectroscopy. Major properties of filters under diffuse-light illumination are discussed. The comparisons of spectral diversity between the transmission geometry holograms and the reflection geometry holograms are also studied.(More)
We present a new idea for diffuse source spectroscopy using a Fourier-transform volume holographic spectrometer formed by a Fourier-transform lens, a volume hologram, and a CCD. We show that this spectrometer can operate well under spatially incoherent light illumination. Furthermore, this spectrometer is less bulky, less sensitive to input alignment, and(More)
The spherical beam volume hologram, recorded by a plane wave and a spherical beam, is investigated for spectroscopic applications in detail. It is shown that both the diffracted and the transmitted beam can be used for spectroscopy when the hologram is read with a collimated beam. A new method is introduced and used for analysis of the spherical beam volume(More)
A new technique for optical correlation using gated holographic recording is demonstrated. Several persistent holograms are localized within separate slices as close as 33 microm apart along the crystal. Individual holograms can be dynamically erased and rerecorded with no need to refresh all other recorded holograms. Experimental results showing the(More)
We present a new technique for optical correlation using gated holographic recording by which the holograms are localized in separate slices along the recording medium. We compare the performance of localized holographic correlators ͑LHCs͒ with that of the conventional correlators using normal volume holography. Crosstalk, shift invariance, and the(More)
iii To my wife, My mother and stepfather , My dad, And my grandmother iv ACKNOWLEDGEMENTS Above all, I would like to give honor and thanks to God Almighty, His Holy Spirit who guides me, and His Son Yeshua who is LORD of my life. I would like to thank my advisor, Dr. Ali Adibi, for all the years of providing direction and support. I appreciate your vote of(More)
We propose a computationally efficient scheme to decode two-dimensional (2D) intersymbol interference (ISI) channel with M-ary input. The basic idea is to equalize the channel stage by stage. To begin with the stage with the highest signal power level, the BCJR algorithm is used to equalize each level by averaging the interference of the undecoded levels.(More)
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