Abstract

Several groups have studied photorefractive two-beam coupling in cubic crystals of symmetry group $\overline{4}3\text{m}$, including GaAs^1-7 and InP.^7-11 In these experiments, the grating vector $\overrightarrow{\text{q}}$ usually was along the $\left[1\overline{1}0\right]$ or [001] crystal axis, the "canonical" orientations. Recently it was shown that in Bi₁₂SiO₂₀, a crystal of symmetry group 23 having an identical form of electro-optic tensor but possessing an additional optical activity,¹² rotation of the crystal from the two canonical orientations can increase energy exchange.¹³ In this paper we show that it is possible to obtain a 15.5% increase in energy transfer by rotating an InP:Fe crystal from the canonical positions, revealing the physical mechanism of this effect in the absence of optical activity.

© 1990 Optical Society of America