Abstract

Efficient surface-emitting lasers are desired for applications in optical signal processing, communication, IC interconnection, and computing. Steady progress has been reported over the past few years^1–4, but, to the authors knowledge, a practical design which has output/input characteristics comparable to in-plane diode lasers has not been discussed. We discuss a surface-normal AlGaAs distributed Bragg reflector (DBR) laser, which utilizes parallel connections to a pinipini... active region for electrical drive and quarterwave mirror stacks for feedback as indicated in Fig. 1. In simple terms, the geometry can be viewed as an in-plane multiquantum-well (MQW) laser that is sliced into many longitudinal pieces, which are stacked on top of one another and driven in parallel. Thus it is not surprising that its threshold current and output power can be comparable to an in-plane laser of the same junction area, even though the net length of the active section in the vertical direction is ≤5 μm. Efforts to fabricate this structure have unearthed no significant difficulties. In fact, it appears simpler to fabricate than other geometries that have already been demonstrated^1–4, since no regrowths are required. We are using MBE growth for vertical layer definition, reactive ion etching for uniform vertical columns, and side diffusion for parallel connections to the alternating p- and n-type drive layers.

© 1988 Optical Society of America