Mid-Infrared Frequency Combs based on Single Section Interband Cascade Lasers

Abstract

In this work we show Frequency Comb (FC) and short pulsed operation of mid-infrared Interband Cascade Lasers (ICLs) in a single long section. This is through the use of an adapted ultrafast Quantum Well Infrared Photodetectors (QWIPs), and correlating the microwave beatnotes with high resolution spectra of the ICL. In particular, we will show active mode-locking (ML) of single -section ICL that does not require RF optimisation of the ICL device and highlight its temporal characteristics using Shifted Wave Infrared Fourier Transform Spectroscopy (SWIFTS) analysis to reconstruct the intensity in the time domain.