DEPENDENCE OF OPTICAL GAIN ON CRYSTAL ORIENTATION IN SURFACE-EMITTING LASERS WITH STRAINED QUANTUM-WELLS

We analyze theoretically optical gains in vertical-cavity surface-emitting lasers (VCSELs) for various crystal orientations. The calculation based on the multiband effective-mass theory takes into account the effects of anisotropy and nonparabolicity on the valence subband dispersion. It is found that in VCSELs employing InGaAs/InP strained quantum wells (QWs) with non-(001) orientations except (111), the polarization in the QW plane can be controlled and high gains are obtained. In particular, the gains in VCSELs with (NN1)-oriented (N greater-than-or-equal-to 2) strained QWs are markedly higher than those in the equivalent (001) lasers. (C) 1994 American Insitute of Physics.