Abstract

The dispersion characteristics of space charge waves propagating in a photoconducting material are derived. It is shown that both forward and backward waves can propagate depending on the materials parameters. Special cases include the low attenuation space charge waves used in the past for interaction with acoustic waves. The interaction with optical waves is investigated when the photoconductor is also an electro-optic (i.e., photorefractive) material. It is shown that power can be transferred from the optical waves to the space charge waves and vice versa. Experiments conducted in the past on two-beam interactions are reinterpreted in terms of new types of interactions that involve space charge waves. New experiments for the excitation and detection of space charge waves are proposed.

© 1992 Optical Society of America