High T 0 (140 K) and low-thresholdlong-wavelength strainedquantum well lasers on InGaAs ternary substrates

Strained quantum well lasers emitting in the 1.2 µm region have been fabricated on In0.22Ga0.78As ternary substrates. The threshold current density of the laser with highly reflective facets is 176 A/cm2 at 20°C. The characteristic temperature (T0) of the device has reached 140 K, which is the highest value ever reported for long-wavelength semiconductor lasers.