Dispersion measurements of Terahertz Quantum Cascade Fabry-Pérot cavities and VECSELs

Abstract

A method for obtaining the dispersion of terahertz (THz) quantum cascade lasers (QCL) is presented. By measuring the relative phase of the center burst and first satellite peak within the interferogram of a sub-threshold THz QCL emitting cavity inside a Fourier Transform Infrared Spectrometer (FTIR), the electroluminescence spectrum is determined by Fourier Transform and the group velocity dispersion can be calculated. This method is applicable to any QCL – here shown for Fabry-Pérot (FP) ridge laser as well as VECSEL.