VCSEL polarization control by monolithic surface gratings: a survey of modelling and experimental activities

Abstract

VCSELs have several advantages with respect to edge emitting semiconductor lasers; one of their major drawbacks is the lack of polarization control due to the almost absence of any selecting mechanism in the resonator and active medium. In this paper we will review a technique based on the integration of a shallow grating into the VCSEL output facet, which gives very good results, provided that a careful design is performed.