THE EXPERIMENTAL STUDY OF SELF-PUMPED PHASE CONJUGATOR WITH RING CAVITY IN A PHOTOREFRACTIVE CRYSTAL

Abstract

Two specially cut KNbO3: Fe crystals were used to study the self-pumped phase conjugation with external and internal ring cavities. The design and operation of these conjugators are described. The self-pumped phase conjugator with internal ring cavity can be used as a broadband phase conjugate mirror over a wide wavelength range with high reflectivities ranging from 60% at 488 nm to 63% at 514.5 nm to 40% at 633 nm. A maximum reflectivity of 74.8% at 514.5 nm was obtained. The product P.T, where T is the creation time of the phase conjugate wave and P is the input power, is almost a constant for a given wavelength. The phase conjugate nature of retroreflected beam has been further confirmed by a significant reduction in the specular reflectivity at the input surface of the crystal.