We propose a novel material, GaInNAs, that can be formed on GaAs to drastically improve the temperature characteristics (T 0) in long-wavelength-range laser diodes. The feasibility of our proposal is demonstrated experimentally.

The effect of biaxial strain on the valence bands in (101̄0)-GaN/AlGaN quantum wells (QWs) is theoretically investigated, using the sp3 tight-binding method. The effective mass around the valence band edge in unstrained (101̄0) QWs is reduced to about 1/2 that of (0001) QWs. Under compressive strain, the subband non-parabolicity near the band edge is further reduced due to heavy-hole/light-hole splitting. The optical matrix elements of [112̄0] polarization in these QWs are twice as large as those in (0001) QWs. The reduced effective mass and large optical matrix elements in the (101̄0) QWs are an advantage for short-wavelength laser diodes based on wurtzite GaN.

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≥2) strained QWs are markedly higher than those in the equivalent (001) lasers.

Articles you may be interested inThe effect of silicon doping in the barrier on the electroluminescence of InGaN/GaN multiple quantum well light emitting diodes

No abstract