Brightness enhancement in Non-Hermintian VCSELs

Abstract

Vertical Cavity Surface Emitting lasers (VCSELs) are compact and efficient light sources useful for a variety of applications. However, due to lack of a transverse mode control mechanism, such lasers suffer from poor spatial beam quality, intrinsic spatiotemporal instabilities and nonlinear destabilizing effects such as filamentation and spatial hole burning [1]. Therefore, there is a need for new strategies to manipulate the light wave dynamics to enhance the stability of VCSELs. Recently, non-Hermitian media have become a flexible platform for new functionalities such as asymmetric coupling, unidirectional invisibility, single mode lasing [2-3]. In this presentation, we propose a novel stabilization mechanism for VCSELs to obtain bright and narrow beams. The mechanism relies on non-Hermitian configuration of the laser potential, achieved by simultaneous spatial modulation of the refractive index and gain-loss profiles.