We present theoretical expressions and experimental measurements of the absolute phase shifts of phase conjugators. Photorefractive media, transparent media, saturable absorbers and saturable amplifiers are considered in the analysis. Experimental measurements of the absolute phase shifts are presented for barium titanate, strontium barium niobate and ruby.
"Absolute Phase Shift of Phase Conjugators", Proc. SPIE 0613, Nonlinear Optics and Applications, (16 June 1986); doi: 10.1117/12.960377; https://doi.org/10.1117/12.960377