BICONICAL EMISSION OF SPATIALLY MODE-LOCKED PATTERNS WITH WAVE-NUMBERRATIO ROOT-2 IN A RING CAVITY DEVICE

Bioconical emission with wave-number ratio root 2 is observed in the n umerical simulations of the ring cavity with diffraction effects, on t he defocusing side of the resonance. As the intensity of the plane-wav e beam increases, a sequence of stationary patterns is observed, and u nderstood via a nonlinear analysis. The first pattern with (4-4) peaks is a bisquare resulting from a strong coupling between two quasireson ant sets of modes with wave numbers K and root 2K. This pattern destab ilizes at the onset of the drift bifurcation, into a new (4-4) pattern with a smaller wavelength, that splits into two twisted bisquares, wi th a 53 degrees rotation angle ensuring the wave-vector locking, or th e spatia periodicity of this (8-8) structure.