Abstract

We demonstrate photorefractive oscillations between two BaTiO₃ crystals with intracavity phase and amplitude modulation and multimode fibers. Two configurations are discussed. In one, two semilinear passive phase conjugate mirrors (PPCMs) are placed in tandem, and the first PPCM is pumped externally. This excites all the other beams, i.e., the other three beams of the first PPCM and all four beams of the second, causing the buildup of oscillations between the two crystals, even in the presence of a slide or multimode fiber between the crystals. In the second configuration, two double-phase conjugate mirrors face each other with a slide placed between them and each is pumped separately by different image bearing beams which may be derived from separate lasers. Oscillations build up which support the three different images simultaneously. The automatic self-tracking of the oscillating beams is due to the self-induced gratings in the crystals, allowing the oscillators to support a large bandwidth of transverse modes in the cavities. Applications in real-time image processing are discussed.

© 1986 Optical Society of America