Dynamics of self-pumped double PC mirrorsbased on photorefractive nonlinearity

It is shown that apart from a dynamic hologram formed in the self-crossing region of input beams [the first phase-conjugation (PC) channel] in a single-crystal double PC mirror, additional refractive-index gratings spontaneously develop, which form the second PC channel with the interaction geometry typical of two-crystal PC mirrors. The competition between these channels leads to a complicated spatiotemporal dynamics of generated nonlinear waves. Depending on the experimental conditions, PC with the efficiency of up to 70 % – 80 % is possible and dynamic structures can be formed from thin soliton-like filaments.