Selecting optimal incident conditions in a cat-type self-pumped phase conjugator by erasure

We have observed an extra fanning beam along the direction for obtaining the maximum coupling strength and it affects the reflectivity of a cat self-pumped phase conjugator. The production of the extra fanning beam for obtaining the highest coupling strength can be understood by applying Sun's method. The angle deviation of the direction of the extra fanning beam and the fanning loops affects the generation and reflectivity of the phase conjugate wave. It can be controlled by erasure. Moreover, the erasure of the crystal can be treated as another control factor of incident condition for obtaining the maximum reflectivity in a Cat SPPCM in Sun's method. We have modified Sun's method by considering this factor. We find the modified Sun's method can be used to estimate the optimal incident conditions for obtaining the relatively high reflectivity of a Cat SPPCM in a more accurate way.