Mutually pumped phase conjugator using a BaTiO3 crystal having two inclined faces

A pentagon-shaped undoped BaTiO3 crystal was used to construct a high-quali ty mutually pumped phase conjugator. It yields two very stable phase-conjug ate outputs (+/-1.7% fluctuation in intensity) with high reflectivity (the highest approximate to 45%) when the two incident beams are of equal intens ities. The response time of the conjugator is rather fast (approximate to 3 s) and the tolerance of the acceptance angle is large too (approximate to 100 degrees). Fine structures (35 mum) in an image, after passing through a phase aberrator, can be recovered by the conjugate waves yielded by this c onjugator.