Low-threshold continuous-wave two-stack quantum-dot laser with reduced temperature sensitivity

Data are presented on continuous wave operation of two-stack quantum dot lasers designed with reduced temperature sensitivity in their threshold. The InAs quantum dots are designed to have a wide energy spacing (/spl sim/102 meV) between the ground and first excited radiative transitions. Selectively oxidized stripe lasers have continuous wave threshold currents as low as 1.2 mA for 2 μm wide stripes and minimum threshold current densities of 26 A/cm
²
for 13-μ-m wide stripes. Broad area lasers have continuous wave threshold current densities as low as 40 A/cm
²
, even for p-up mounting. Ground state lasing is obtained up to the highest temperature measured of 326 K.