R. W Boyd, D J Gauthier, M Kauranen, M S Malcuit, W R Tompkin, "Polarization Properties Of Phase Conjugation By Degenerate Four-Wave Mixing In Saturable Absorbers," Proc. SPIE 1060, Nonlinear Optical Beam Manipulation and High Energy Beam Propagation Through the Atmosphere, (8 August 1989);