Abstract

We have investigated photorefractive two-beam coupling (TBC) and degenerate four-wave mixing in a new photorefractive polymer (PRP) material. The observed dependence of grating diffraction efficiency on applied poling field differs strongly from that predicted by standard models, exhibiting a sharp decrease with field over a certain range of field values. We describe a model which incorporates competition between photorefractive gratings and photoisomerization gratings in the material and which accounts for the observed behaviour satisfactorily.

© 1998 IEEE