Nonlinear on-switching of high spatial frequency patterns in ring vertical cavity surface emitting lasers

We show that the basic on-switching of spatial patterns (modes) in lasers is a result of an intrinsic nonlinear dynamical effect-the modulation instability (MI) of the self consistent field patterns in the complex nonlinear medium-and present the threshold conditions for the formation of the patterns (modes). We emphasis a ring shaped laser-having no “hard ” boundary conditions-which makes it the best system to exhibit the “clean” phenomena both experimentally and theoretically. A vertical cavity surface-emitting laser (VCSEL) is a semiconductor laser with a 2-dimensional resonator and thus is ideal for the implementation of ring shaped laser with periodic boundary conditions in the azimuthal coordinate