Long-wavelength mid-infrared (MIR) frequency combs with high power and flexible tunability are highly desired for molecular spectroscopy, including investigation of large molecules such as C60. We present a high power, phase-stabilized frequency comb near 10 μm, generated by a synchronously pumped, singly resonant optical parametric oscillator (OPO) based on AgGaSe2. The OPO can be continuously tuned from 8.4 to 9.5 μm, with a maximum average idler power of 100 mW at the center wavelength of 8.5 μm. Both the repetition rate (frep) and the carrier-envelope offset frequency (fceo) of the idler wave are phase-locked to microwave signals referenced to a Cs clock. We describe the detailed design and construction of the frequency comb, and discuss potential applications for precise and sensitive direct frequency comb spectroscopy.

中文翻译：

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接近 10 μm 的相位稳定 100 mW 频率梳

分子光谱学（包括 C60 等大分子的研究）非常需要具有高功率和灵活可调性的长波长中红外 (MIR) 频率梳。我们提出了一种接近 10 μm 的高功率、相位稳定频率梳，由基于 AgGaSe2 的同步泵浦单谐振光参量振荡器 (OPO) 产生。OPO 可在 8.4 至 9.5 μm 范围内连续调谐，中心波长为 8.5 μm 时的最大平均空闲功率为 100 mW。闲频波的重复率 (frep) 和载波包络偏移频率 (fceo) 都锁相到以 Cs 时钟为参考的微波信号。我们描述了频率梳的详细设计和构造，并讨论了精确和灵敏的直接频率梳光谱的潜在应用。