Abstract

The polarization of common vertical-cavity surface-emitting lasers (VCSELs) is very sensitive to optical feedback [1], On the other hand, VCSELs which are polarization-stable are highly sought-after for many applications including single-mode fiber-based data transmission and optical sensing. Among the several approaches to achieve polarization stability in VCSELs, the use of a monolithically integrated surface grating was proven to be particularly effective [2], To the best of our knowledge, up to now none of the stabilization methods was rigorously tested against the important practical case of optical feedback. In this paper we compare the polarization behavior of a transverse single-mode, top- emitting, 925 nm wavelength, 4 pm oxide aperture diameter grating relief VCSEL (grating with 0.8 pm period, 57 nm depth, and 3.6 pm outer diameter) with a nominally identical standard VCSEL for unpolarized optical feedback in the long external cavity regime, in which the feedback effects are qualitatively independent from optical phase variations.

© 2007 IEEE