Ring self-pumped phase conjugator for high energy pulses at 1064 nm with rhodium-doped BaTiO3

An external loop phase conjugate mirror with a 45 degrees-cut rhodium-doped BaTiO3 is constructed and characterized. The external loop is composed of an image-relay telescope, a 90 degrees-image rotator and a phase modulator. The stable phase conjugation is achieved with nanosecond 20 mJ pulses at 1 063 nm. Reflectivity of the mirror as high as 53% is obtained with a respon se time of 13 s at a repetition rate of 100 Hz. Wavefront compensation is a pplied to a laser beam whose quality is as poor as M-2 > 100.