PHASE CONJUGATION IN METHYL-ORANGE-DOPED PVA FILMS BY PHOTOINDUCED ANISOTROPY

The influence of photoinduced anisotropy (dichroism and birefringence) in methyl-orange-doped polyvinyl alcohol film upon optical phase conjugation is investigated. The reflectivity of the phase-conjugate (PC) beam due to degenerate four-wave mixing (DFWM) is measured under the condition that the polarization states of a probe and two pump beams are mutually orthogonal. The more efficient PC beam generates at 515 nm rather than at 488 nm. At 515 nm, the reflectivity of the PC beam exceeds 10 percent about 30 minutes after the initiation of DFWM. It was found that birefringence rather than dichroism contributes to the generation of the PC beam at 515 nm. © 1990 IOP Publishing Ltd.