Threshold behaviour and phase conjugation in an arch mutually pumped phase-conjugate mirror

The dependence of the threshold coupling strength on the loss parameter and the incident-beam ratio is calculated and shown for a new mutually pumped phase conjugator with a novel photorefractive crystal of copper-doped potassium sodium strontium barium niobate, in which both incoherent beams are incident upon the negative-c face and they travel in geometric paths similar to the outline of two arches. The maximum reflectivity attained is 21%. The tolerances of the output to both incident angles and positions are assessed. A curve fit is also made between the measured results and theoretical calculation.