Submilliamp threshold current (0.62 mA at 0°C) and high output power (220 mW) 1.5 μm tensile strained InGaAs single quantum well lasers

The strain dependence of the threshold current density of λ = 1.5 μm wavelength tensile strained InxGa1−xAs (0.22 < x < 0.53)–InGaAsP single quantum well (SQW) lasers is reported. The optimum indium mole fraction was found to be 0.32 (1–5% strain), resulting in TM polarised lasers with threshold current densities as low as 92 A/cm2. Using this SQW, buried heterostructure lasers with 0.62 mA threshold and 220 mW CW output power were realised.