Investigation of the characteristics of a wavefront-reversing mirror utilizing a photorefractlve strontium barium niobate crystal

An experimental investigation was made of the time and energy characteristics of a wavefrontreversing mirror with a self-intersecting laser beam using a strontium barium niobate crystal as the nonlinear medium. A study was made of the dependence of the reflection coefficient R of the wavefront-reversing mirror and of the reversed beam formation time τ on the length of the wave vector of the induced grating and the refractive index. It was found that in a certain range of wave vector lengths, the reflection coefficient showed a sharp drop. A theoretical explanation of the observed dependences was based on calculations of the strength of the coupling of the light waves in the medium. The dependences of R and τ on the intensity and divergence of the laser beam were studied. The conditions for conservation and erasure of the refractive index grating in the crystal were investigated.