Self-enhancement and the photo-induced macroscopic field in the self-pumped phase conjugators

A novel phenomenon of self-enhancement in reflectivity of a self-pumped phase conjugator during the time interval in which no light illuminates the conjugator was observed. The response time of self-pumped phase conjugators of Ce-doped or Mn-doped potassium sodium strontium barium niobate (KNSBN) single-domain crystal was shortened significantly by using an intermittent light. A qualitative explanation on the experimental results was given by using a charge carrier migration model via measuring the photovoltaic and pyroelectric fields. Some further experiments were also done to support the analysis. The reduction in the conjugation fidelity of the self-pumped phase conjugators was also explained in terms of a photo-induced internal field.