Phase-stabilized, 15 W frequency comb at 28–48 μm

TLDR

The authors present a high‑power OPO‑based frequency comb for the mid‑IR region. The comb is generated by a singly resonant OPO using periodically poled lithium niobate, pumped synchronously by a 10 W femtosecond Yb:fiber laser at 1.07 μm, yielding a tunable idler from 2.8 to 4.8 μm with 0.3 μm bandwidth and up to 1.5 W output, and its stability is verified via heterodyne beating. The resulting OPO provides a suitable source for mid‑IR frequency comb spectroscopy.

Abstract

We present a high-power optical-parametric-oscillator (OPO) based frequency comb in the mid-IR wavelength region. The system employs periodically poled lithium niobate and is singly resonant for the signal. It is synchronously pumped by a 10 W femtosecond Yb:fiber laser centered at 1.07 microm. The idler (signal) wavelength can be continuously tuned from 2.8 to 4.8 microm (1.76 to 1.37 microm) with a simultaneous bandwidth as high as 0.3 microm and a maximum average idler output power of 1.50 W. We also demonstrate the performance of the stabilized comb by recording the heterodyne beat with a narrow-linewidth diode laser. This OPO is an ideal source for frequency comb spectroscopy in the mid-IR.