Abstract

In the application of a photorefractive double phase conjugate mirror, the transient buildup and the dynamic behavior are both interesting and important. The temporal instabilities of the driven DPCM were studied recently.¹ In this work we present a numerical study of the transient buildup as a function of various parameters: total intensity, beam ratio, steady state photorefractive coupling gain, and seeding levels. We take the standard four-wave mixing model² including the Debye relaxation equation for the space-charge electric field, using the typical boundary condition for the DPCM and no initial space-charge field. We find that (1) the buildup time of the DPCM, which is defined as the time the phase conjugate reflectivity reaches 90% of its steady state reflectivity, is also inverse proportional to the total intensity, (2) the buildup time decreases and tends to saturate as the steady state coupling gain increases, (3) the buildup time increases approximately quadratically as incident beam ratio deviates unity.

© 1989 Optical Society of America