Abstract

Optical frequency combs now enable dramatically improved acquisition rates, resolution and sensitivity for molecular spectroscopy mostly in the visible and the near-infrared ranges. Extension to the mid-infrared “molecular fingerprint region” (2–20 μm) is crucial as many molecules undergo strong characteristic vibrational transitions in this domain. However, the generation of frequency combs in the mid IR is comparatively under-developed [1]. A remaining challenge is to create combs with sufficient bandwidth and significant power per comb component. A novel route to mid-infrared frequency comb generation is based on ultra-high Q optical microresonators [2]. The distinguishing advantages of microresonator-based frequency combs are compactness, large comb mode spacing, and high power per comb line. The first step of Kerr microresonator frequency combs has been demonstrated at the onset of the mid-infrared region by pumping two different platforms [3,4].

© 2015 IEEE