Patterned quantum well semiconductor lasers

Abstract

Lateral patterning of the bandgap in semiconductor quantum well (QW) lasers is essential for achieving lateral carrier confinement and for integrating diode lasers with other optoelectronic components having a different bandgap. In particular, lateral carrier confinement into extremely narrow (<0.1 µm) dimensions is required for the realization of low-dimensional quantum wire and quantum dot lasers. We have developed a new technique for lateral patterning of semiconductor QW lasers.1 The technique consists of growing otherwise conventional QW laser structures on patterned, nonplanar substrates. The resulting patterned QW heterostructures exhibit lateral variations in the effective QW bandgap. Patterned QW lasers grown by molecular beam epitaxy2 have active region widths of ~1 µm and exhibit threshold currents as low as 0.7 mA. Patterned QW lasers grown by organometallic chemical vapor deposition have crescent-shaped quantum wire active regions <0.1 µm wide. Lasing due to transitions between quasi 1-D subbands in these quantum wires has been observed.3