The role of temperature in quantum-cascade laser waveguides

The role of temperature on the properties of quantum-cascade laser (QCL) waveguides is investigated. One-dimensional waveguide parameters are obtained using a transfer-matrix technique and the complex dielectric constants of the waveguide layers are calculated using a semi-classical Drude-Lorentz model. To model the effect of temperature on the waveguide parameters, a temperature dependent electron mobility is incorporated within the Drude- Lorentz framework. It is shown that by including the effect of temperature, a significant improvement in the agreement with experiment of the waveguide loss and hence the laser threshold current density can be achieved.