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Kehan Tian

Publications and source records attributed to Kehan Tian.

3 recordsLinked to original sources

Diffraction from deformed volume holograms: perturbation theory approach.

We derive the response of a volume grating to arbitrary small deformations, using a perturbative approach. This result is of interest for two applications: (a) when a deformation is undesirable and one seeks to minimize the diffracted field's sensitivity to it and (b) when the deformation itself is the quantity of interest and the diffracted field is used as a probe into the deformed volume where the hologram was originally recorded. We show that our result is consistent with previous derivations motivated by the phenomenon of shrinkage in photopolymer holographic materials. We also present the analysis of the grating's response to deformation due to a point indenter and present experimental results consistent with theory.

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Coherence patterns originating from incoherent volume sources.

We derive the complex degree of coherence that originates from generalized incoherent two- and three-dimensional sources. Further, we find the locus of maximum coherence and analyze the dependence of the decay of coherence on source thickness.

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Cross talk in resonant holographic memories.

We analyze cross talk in resonant holographic memories and derive the conditions under which resonance improves storage quality. We also carry out the analysis for both plane-wave and apodized Gaussian reference beams.

Journal Article↗