Abstract

Broadband coherent light sources consisting of equally-spaced discrete lines in the frequency domain, also called optical frequency combs (OFCs), constitute a very powerful tool in a vast number of applications such as optical frequency metrology, biology, and astronomical spectrograph calibration, optical fiber wavelength division multiplexing (WDM), microwave generation and molecular spectroscopy [1–4]. The latter application has attracted significant interest especially in the mid-infrared range (from 2-µm to 16-µm) where various relevant molecules, such as carbon dioxide and ammonia, exhibit vibration fingerprints. Various OFCs generated at 2-µm wavelengths have recently been reported based on different configurations [3,5].

© 2019 IEEE