Investigation into self-pumped and mutually pumped phase conjugation with beams entering the negative c face of doped (K↓(0.5)Na↓(0.5))↓(0.2) (Sr↓(0.75)Ba↓(0.25))↓（0.9）Nb↓(2)O↓(6) crystals

摘要

We investigated some novel geometries of self-pumped phase conjugation (SPPC) and mutually pumped phase conjugation (MPPC), relying on total internal reflection both from the a face and from corners, with beams entering the negative c face of doped (K↓(0.5)Na↓(0.5))↓(0.2) (Sr↓(0.75)Ba↓(0.25))↓（0.9）Nb↓(2)O↓(6) crystals. The different situations for internal light paths and their direct transformation at the same incident wavelength were observed. Similarities and differences between SPPC and MPPC are discussed. The dynamic features of SPPC and MPPC in different situations were also observed. Three or more four-wave-mixing interaction regions were clearly observed inside the phase conjugators. The multistep interaction and its influence on the response rate and conjugation fidelity are analyzed. The large size of the samples seems necessary to ensure an optical path that is long enough for multistep bifurcation. The stability of the light channels is discussed based on the fanning effect. # 1997 Optical Society of America