Skip to Main Content
Temperature-dependent cavity length studies have been performed on multiple stack strain compensated InGaAs quantum-dot (QD) active region broad stripe laser structures grown by metal-organic chemical vapor deposition. The characteristic temperature coefficients of the threshold current density (T0) and external differential quantum efficiency (T1) were calculated from variable temperature measurements. The correlation of the T0,T1 values and the extracted values of the characteristic temperature coefficients of the transparency current density, material gain, injection efficiency, and internal loss (Ttr,Tg0,Tηinj,Tαi) from the temperature-dependent study is discussed. The T1 values are higher than 400 K for five-stack QD laser structures, comparable values to conventional quantum-well (QW) laser structures. T0 values are lower than 100 K. Extracted material gain parameters are found to increase with increasing temperature for the three-stack QD structure, and are nearly temperature independent for the five-stack structure, different to that observed in InGaAs QW lasers.