Self-pumped, optical phase conjugation method and apparatus using pseudo-conjugator to produce retroreflected seed beam

摘要

An optical input (18) beam is transmitted through a non-linear medium (12) capable of two-wave mixing gain by photorefractive, Brillouin, Raman, or other non-linear optical mechanism. A pseudo-conjugator (16) retroreflects the input beam which has passed through the medium, back into the medium. The retroreflected beam acts as a seed, which lowers the threshold for producing a self-pumped conjugate reflected beam in the medium by stimulated scattering. The pseudo-conjugator may be a flat array of retroreflecting elements in the form of spheres or corner reflectors. A mosaic pattern of conjugating elements can be phase-locked to yield larger apertures and/or energy scaling, in a master-oscillator, power-amplifier (MOPA) (80), (90), or a four-wave mixer (FWM) (120) configuration. The retroreflected beam can be modulated to temporally encode information onto the conjugate beam, and/or polarized to increase the system efficiency. The input and self-pumped conjugate reflected beams can be used as reference or pump beams in a FWM configuration.