Measurement of phase shift of photorefractive gratings by a novel method

A novel and sensitive method to measure the phase shift of the photorefractive phase grating with respect to the interference pattern is demonstrated that uses no moving mechanical parts. Results are presented for the measurement of the electrical field dependence of the phase shift in KNbO/sub 3/ crystals with various Fe concentrations. Some experimental results are also presented that show the strong influence of internal photovoltaic fields on the phase shift of the space-charge field.<
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