Measurement of the space-charge field in photorefractive crystals under external field

摘要

Transformation of the small phase modulation (rapidly varying in time) into the intensity modulation during two-wave mixing in photorefractive crystals is applied for measurements of the space-charge-field amplitude created in such cubic crystals as Bi_(12)TiO_(20), and GaP. Measurements were carried out at different recording mechanisms: under DC-external field and under alternating field of the square-wave form. The theory of the vectorial wave coupling is used to interpret the measured results.