飞秒光学频率梳高精度气体吸收光谱技术进展

飞秒光学频率梳以其频谱宽、脉宽窄、频率稳定度高等优点，对光学频率计量、绝对距离测量、高精度光谱测定产生重大影响。飞秒光学频率梳的时域特性和频域特性溯源至微波频率基准，使得高精度气体吸收光谱探测成为可能。飞秒光学频率梳光谱技术具有测量速度快、光谱灵敏度高、分辨率高、信噪比高等优点，因此加大对飞秒光学频率梳光谱技术的研究力度将更好地服务于环境保护、工业生产、生物医学、科学研究等各领域。飞秒光频梳高精度气体吸收光谱主要可分为光频梳腔衰荡光谱、光频梳腔增强光谱和双光频梳多外差光谱。其中，根据采集方式不同，光频梳腔增强光谱又可分为梳齿游标测量法、虚拟成像相位阵列测量法和傅里叶变换测量法。目前，国外已广泛开展相关研究，而国内仍处于起步阶段。本文综述了飞秒光学频率梳高精度气体吸收光谱探测的主要技术方法，展示了不同测量方法典型的实验方案，分析了各探测方法的优缺点，并追踪了主要研究小组的前沿成果。

Technique Progress of High-Precision Gas Absorption Spectroscopy with Femtosecond Optical Frequency Comb

Femtosecond optical frequency comb, with large spectral range, narrow pulse width, high stability of frequency and many other remarkable properties, has a significant impact on optical frequency metrology, absolute distance measurement and high-precision spectroscopy. The time-domain and frequency-domain properties of femtosecond optical frequency comb is traced back to the microwave frequency standard, making it possible to open up the door to high-precision gas absorption spectrum detection. Femtosecond optical frequency comb spectroscopy has some excellent performances, such as fast measurement, high sensitivity, high resolution, high signal-to-noise ratio and so on. Therefore, more investments on femtosecond optical frequency comb spectroscopy will better make contribution to the environmental protection, industrial production, biological medicine, scientific research and other social fields. High-precision gas absorption spectroscopy with femtosecond optical frequency comb mainly includes frequency comb based cavity ring-down spectroscopy, cavity-enhanced frequency comb spectroscopy and dual-comb multi-heterodyne spectroscopy. Among them, according to the data collection, cavity-enhanced frequency comb spectroscopy can be divided into comb vernier method, virtually imaged phased array method and Fourier transform method. At present, related research has been widely carried out abroad, and domestic research is still in its infancy. This review summarizes main techniques in the high-precision gas absorption spectrum detection based on optical frequency comb, and demonstrates typical experimental schemes for different methods. It also analyzes the advantages and disadvantages of each method, and tracks frontier achievements of main research groups.