Abstract

We have measured real and imaginary contributions to picosecond phase conjugation in polydiacetylenes at 1064 nm. A careful analysis of their dependences vs pump intensity shows that we have a regular two-photon absorption up to 1-GW/cm² pump intensity. This absorption presents a dramatic increase at large pump intensities leading to a tenfold increase of both real and imaginary parts of the effective from 1 to 3 GW/cm².

© 1989 Optical Society of America