Interband cascade laser frequency combs

Interband cascade lasers (ICLs) have emerged as efficient, room-temperature semiconductor light sources with relatively highwallplug effiency and low power consumption in the 3–6 µm wavelength region. The recent discovery that ICLs can generateself-starting optical frequency combs has triggered a new avenue of research that ultimately promises to provide broadband,gap-free chemical sensing sources for the simultaneous detection of multiple species or rapid scanning of broad absorptionfeatures. Here we review ICL frequency combs for the first time, focusing on device topologies, spectral characteristics, andfrequency stabilization. Future perspectives such as the development of on-chip dual-comb spectrometers based on the ICLplatform, real-time probes of molecular dynamics, and combs that use harmonic comb states to generate millimeter waves arealso discussed.