Experimental investigations are presented of cross-polarization two-beam coupling in a photorefractive GaAs crystal, in which two mutually coherent laser beams with the same polarization state (e.g., s waves) interact to generate and couple energy into an orthogonally polarized beam (p wave). We demonstrate cross-polarization coupling of 1.06-μm YAG laser beams (both cw and pulsed) in a semi-insulating single crystal of GaAs and show that the coupling coefficient is ˜0.4 cm−1. The experimental data are shown to be in good agreement with the theoretical results for the weak-coupling regime; the theoretical results are calculated from a set of coupled equations describing generalized two-beam coupling in cubic photorefractive crystals. The photorefractive response time of our crystal is also determined using nondegenerate cross-polarization two-beam coupling and is shown to be approximately 0.5 msec at the total intensity of 1 W/cm2.
© 1988 Optical Society of America
Tallis Y. Chang, Arthur E. Chiou, and Pochi Yeh, "Cross-polarization photorefractive two-beam coupling in gallium arsenide," J. Opt. Soc. Am. B 5, 1724-1729 (1988)