Temperature-Independent Performance of an 8-Layer λ ~1.3 μm InAs/GaAs Quantum-Dot Laser

We report high-performance broad-area eight-layer InAs/GaAs quantum-dot lasers (QDLs) emitting at 1.3 μm in the pulse and continuous-wave (CW) operations. Operational characteristics of the fabricated QDLs, including the emission wavelength, output power, threshold-current density, differential quantum efficiency, and characteristic temperature, are investigated at different temperatures. For as-cleaved facets of 100 μm wide and 1 mm cavity-length device, an output power of 100 mW is achieved at 1 kHz with 5% duty cycle and 49 mW in the CW operation. The device exhibits a threshold-current density of 56 A/cm2 at room temperature in both the operating modes and increases to 71 and 80 A/cm2 the in the pulse and CW modes, respectively, at 343 K. Over a temperature range of 298K to 343 K, we calculate the threshold characteristic temperature of 166K and 119K and slope-efficiency characteristic temperature of 2061K and 408K in the pulse and CW modes, respectively. The laser exhibits differential quantum efficiency of 41% and 32% in the pulse and CW mode, respectively. We observed that the device exhibited negligible dependence over a temperature range of 298K to 343 K.