V. I. Nikonov

Phase conjugation under four-wave mixing on resonant and thermal nonlinearities at relatively high reflection coefficients

The dependences of the reflection (transmission) coefficients and the half-width of the spatial frequency band on the pump-wave intensity are obtained for an object (signal) wave in degenerate and quasi-degenerate four-wave mixers on resonant and thermal nonlinearities. The effect of the difference of the pump-wave frequencies on the phase-conjugation quality is studied at relatively high reflection coefficients.

Diffraction efficiency of a dynamic hologram in a reversible photochromic medium with allowance for diffusion of photochromic particles

Spatial resolution of a dynamic hologram in a reversible photochromic medium is analyzed, with allowance made for diffusion of photochromic particles. It is shown that the bandwidth of spatial frequencies of a thin hologram decreases over time, approaching the value determined by the diffusion coefficient and the hologram recording/erasing time. The optimum relationship between the intensity of the beam that records the volume hologram and the parameters of the photochromic particles is found for which the difference between the limiting value of the bandwidth of spatial frequencies of the volume hologram and the value of the band-width of spatial frequencies of a thin hologram located in the plane z=0 is the greatest.

Precision of wavefront reversal during four-photon interaction of nonmonochromatic waves

The form of the point spread function is found for a stabilized four-photon radiation converter. The functional dependence of the maximum, half-width, and phase shift at the point spread function modulus half-width on the frequency shift of the interacting waves is investigated when the focal planes of the incident and reflected waves coincide. The dependence of the resolution of a four-photon radiation converter as a function of the spectral width of the interacting waves was analyzed with the monochromaticity of these waves taken into account. The effect of the rate of change of the linear phase difference between the different components of the reflected wave on the coherent component of the point spread function was studied.