We study the polarization properties of optically-pumped vertical-cavi
ty semiconductor lasers (VCSELs) pumped with a TEM,, beam and which al
so oscillate in this mode. When the two-lobed pump pattern is rotated,
the binefringence of the laser changes periodically by +/- 3.8 GHz ac
companied by polarization rotation. We attribute these effects to stre
ss-induced birefringence. (C) 1998 Elsevier Science B.V. All rights re
served.