InGaAs/GaAs vertical-cavity surface-emitting lasers with AlAs selective oxide layers

A laser operating at low threshold current is indispensable for the construction of superparallel optical interconnections. Initially we examine the current threshold characteristics of surface emitting ZnGaAs/GaAs lasers, and demonstrate the possibility for working with a threshold current below 100 mu A. Next, vertical-cavity AlAs oxide layers are used, since they are helpful in achieving a low threshold surface-emitting laser, and the optimum conditions for forming the AlAs oxide layer 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 reduction of the dark recombination current. Further low threshold current operation should be achievable by fine control and micronization of oxide layers. (C) 1998 Scripta Technica.