We report on the modeling and optical characterization of AlGaAs/InAs quantum-dot microring diode lasers designed for terahertz (THz) difference frequency generation (DFG) between two whispering gallery modes (WGMs) around 1.3 $\mu$m. In order to investigate the spectral features of this active device in the two frequency ranges, we performed different measurements on ad hoc passive samples. For the study in the telecom range, we used transmission measurements on microcylinders with integrated coupling waveguides. For the analysis in the THz range, we used reflectivity spectra on 2D arrays of identical double-metal microcylinders. The good agreement that we demonstrate between experimental results and design parameters is crucial towards the achievement of active phase-matched THz emitters.
I E E E Transactions on Terahertz Science and Technology, 2013, Vol 3, Issue 4, p. 472-478