A set of twelve specially doped lithium niobate crystals were grown to test the effect of the dopant on holographic recording in the crystals via the photorefractive effect. The crystals were doped with Ce, Co, Cr, Cu, Fe, Mn, Ni, Rh, Tb, Fe:Ce, Fe:Cr, and Fe:Mn. The transmission spectra was measured for each crystal and holograms have been written in each of the crystals with wavelengths from 457 nm to 671 nm. The wavelength sensitivity, scattering, and stability of the holograms varied substantially among the crystals. A qualitative description of the hologram's properties and a comparison of sensitivities between the crystals will be presented.
We demonstrate a simple all-optical realization of programmable edge enhancement and edge-enhanced correlation using novel photorefractive polymers. We show that the higher non-Bragg order in a two-beam coupling scheme contains the edge enhancement of the object when placed in the path of one of the incident beams. Also, this arrangement provides a scheme for writing joint transform correlation dynamic holograms, which can be read by a third beam. The correlation is edge enhanced, and the correlation peak increases with the applied bias voltage. Numerical results without and with beam fanning are presented. Theoretical predictions are reconciled with experimental results.
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