Spatiotemporal period doubling in a nonlinear interferometer with distributed optical feedback

A single-pass nonlinear interferometer with feedback field rotation is considered. Increasing feedback gain results in excitation of spatial subharmonics that distort optical reverberators, which are basic output patterns of the system. Features of the period-doubling process depend on the number of the reverberator's petals. A new spatiotemporal effect is observed: A basic structure with an odd number of petals is perturbed not by a static subharmonic but by a rotating wave.