Highly strained 1.24-μm InGaAs/GaAs quantum-well lasers

Highly strained InGaAs/GaAs quantum wells grown at very low temperature $\text{(380\hspace{0.05em}°}\mathrm{C})$ have been studied. The critical thickness of the ${\mathrm{In}}_{\text{0.38}}{\mathrm{Ga}}_{\text{0.62}}\mathrm{As}$ quantum well is 8.8 nm and the photoluminescence peak is at 1.24 μm. An edge-emitting ${\mathrm{In}}_{\text{0.388}}{\mathrm{Ga}}_{\text{0.612}}\mathrm{As/GaAs}$ quantum-well laser demonstrates an emission wavelength of 1.244 μm at $\text{18\hspace{0.05em}°}\mathrm{C}.$ The threshold current density is $\text{405\hspace{0.17em}}{\mathrm{A/cm}}^2$ for an as-cleaved diode laser with 873-μm cavity length. The internal quantum efficiency and laser cavity loss are 93% and $\text{6.4\hspace{0.17em}}{\mathrm{cm}}^{\text{−1}},$ respectively.