Two-wave mixing in Stark geometry photorefractive quantum wells using moving gratings

Nonreciprocal energy transfer between two coherent laser beams during two-wave mixing requires a photorefractive phase shift between the interference pattern and the resulting space charge. The symmetry of the Stark geometry photorefractive quantum wells forbids a phase shift using either de or ac fields, We present the first experimental demonstration of nonreciprocal energy transfer during two-wave mixing using moving gratings. Optical energy exchange is observed in photorefractive p-i-n quantum well diodes with photorefractive gains approaching 1000 cm(-1) and exhibiting complex spatio-temporal dynamics. (C) 1996 American Institute of Physics.