Abstract

Steady state moving space-charge fields are established when two monochromatic optical fields with constant frequency offset interfere inside photoconductive semiconductors containing deep-level donor sites. Such steady-state moving space-charge fields generate dc photocurrents that can be used to evaluate material characteristics.^1,2 The interference of the pump and a non-monochromatic signal optical field, however, creates multiple moving space-charge fields. The various components of the moving space-charge fields generate short-circuit ac photocurrents that can be simplified to those studied earlier³ under the same approximations assumed by the authors in Ref 3. In addition to the ac photocurrents, a dc photo-current is generated by the steady motion of all the moving space-charge fields. It is given by

© 1995 Optical Society of America