High power, continuous wave, room temperature operation of λ ∼ 3.4 μm and λ ∼ 3.55 μm InP-based quantum cascade lasers

We report two highly strain-balanced InP-based AlInAs/GaInAs quantum cascade lasers emitting near 3.39 and 3.56 μm. A pulsed threshold current density of only 1.1 kA/cm2 has been achieved at room temperature for both lasers with characteristic temperatures (T0) of 166 K and 152 K, respectively. The slope efficiency is also relatively temperature insensitive with characteristic temperatures (T1) of 116 K and 191 K, respectively. Continuous wave powers of 504 mW and 576 mW are obtained at room temperature, respectively. This was accomplished without buried ridge processing.