InGaAs/GaAs quantum dot lasers

InGaAs quantum dots (QDs) grown by strained-layer epitaxy on GaAs can accommodate more In than planar growth and present an interesting approach for realizing GaAs-based laser diodes that operate in the 1.1 to 1.3 μm wavelength range. Although QD emission wavelengths as long as 1.3 μm have been reported, lasing in edge-emitting devices has been limited to wavelengths just over 1.0 μm. Recently, we found that for optimized growth conditions, QD electroluminescence efficiency at 1.3 μm is comparable to good InGaAs quantum wells emitting at 0.98 μm. In particular, the use of separate and alternating sub-monolayer depositions increases the emission wavelength to 1.3 μm and leads to high electroluminescence efficiency, while keeping the total In content of the deposited material to a minimum to avoid excessive strain. We describe the influence of growth method on the formation and emission characteristics of self-assembled InGaAs/GaAs QDs and describe device characteristics from edge emitting lasers using these QD active regions