Taming spatio-temporal lasing instabilities with wave-chaotic microcavities

Spatio-temporal instabilities are widespread phenomena resulting from complexity and nonlinearity. In broad-area semiconductor lasers, the nonlinear interactions of many spatial modes with the active medium can result in filamentation and spatio-temporal chaos. These instabilities degrade the laser performance and are extremely challenging to control. Here we propose and demonstrate a counter-intuitive approach to suppress spatio-temporal instabilities using wave-chaotic or disordered cavities. The interference of many propagating waves with random phases in such cavities disrupts the formation of self-organized structures like filaments, leading to a stabilization of the lasing dynamics. The demonstrated principle for a global control of nonlinear dynamics provides a general and robust solution to stabilize a large variety of high-power lasers.