TRANSMISSION OF TIME MODULATED OPTICAL SIGNALS THROUGH AN ABSORBING PHOTOREFRACTIVE CRYSTAL

We solve the problem of the transmission of time modulated signals in a two-beam coupling photorefractive set-up using an absorbing material. We obtain an analytical expression that describes this phenomenon in absence of pump beam depletion due to beam coupling. We use this expression to analyse the influence of absorption on the photorefractive build-up. We also describe, using this model, the photorefractive beamsplitter response. It is also showed that the mu/2 phase shift between illumination and index gratings is detrimental to a linear detection of the phase variation of the signal beam.