Self-pumped phase conjugation with mechanism transformation in potassium sodium strontium barium niobate

Both multistage and a great number of four-wave mixing interaction region models arising from contradirectional two-wave mixing to generate phase conjugation beam are suggested for the first time to our knowledge with a beam entering negative c face of the crystal. The mechanism transformation with geometric parameters is also observed and discussed. The backscattering beams from random noise beams may be expected to be amplified by contradirectional two-wave mixing under the beam entering negative c face of copper-doped potassium sodium strontium barium niobate. The maximum of reflectivity attains 33%.