Impact of heat dissipation on quantum cascade laser performance

Abstract

We describe a simple and convenient method to analyze the impact of heating in a quantum-cascade laser on its basic performance characteristics. This method has only one fitting parameter, the thermal resistance of the laser, Rth, while the other parameters can be directly measured in pulsed mode. Furthermore, the method can be applied even in the case when lasers do not reach continuous-wave operation. The method was used to analyze a quantum-cascade laser emitting at λ=10.6μm and based on InGaAs-InAlAs material system, lattice-matched to InP. The thermal resistance of Rth = 10 K/W determined using the described method and the flat active region shape imply a vertical thermal conductivity value of κ⊥=0.53 W/m·K for the lattice-matched InGaAs-InAlAs active region, which agrees well with literature values.