INGAAS GAAS VERTICAL-CAVITY SURFACE-EMITTING LASERS WITH ALAS SELECTIVE OXIDE LAYERS/

A laser operating at low threshold current is indispensable for the co nstruction of superparallel optical interconnections. Initially we exa mine the current threshold characteristics of surface emitting ZnGaAs/ GaAs lasers, and demonstrate the possibility for working with a thresh old current below 100 mu A. Next, vertical-cavity AlAs oxide layers ar e used, since they are helpful in achieving a low threshold surface-em itting laser, and the optimum conditions for forming the AlAs oxide la yer are determined. New InGaAs/GaAs surface-emitting lasers with AlAs oxide layer are fabricated and a low threshold current operation of 70 mu A is achieved by current injection through micro-domains and reduc tion of the dark recombination current. Further low threshold current operation should be achievable by fine control and micronization of ox ide layers. (C) 1998 Scripta Technica.