Abstract

Vertical-cavity surface-emitting lasers (VCSELs) possess many advantages over edge emitting lasers like circular beam shape, low threshold current and voltage and the possibility of being grown in two dimensional arrays. However, VCSELs have the drawback of a non stable polarization. Several mechanisms, based on introducing polarization dependent modal gain and/or loss have been proposed in order to eliminate the current and temperature induced polarization switching [1], For some applications however, it is desirable to not only suppress the current and temperature induced polarization switching but also to be able to actively control the polarization of the device. Recently, isotropic and polarization sensitive optical feedback from an extremely short external cavity (ESEC) has been proposed as a way to simultaneously active polarization control and stabilization in VCSELs. Here we show experimental evidences confirming such hypothesis.

© 2007 IEEE