Deng Zejiang, Liu Yang, Zhu Zhiwei, Luo Daping, Gu Chenglin, Zuo Zhong, Xie Gehui, Li Wenxue
State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China.
Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China.
Sensors (Basel). 2021 May 3;21(9):3166. doi: 10.3390/s21093166.
In this paper, we report a scheme providing precise spectral analysis and surface imaging, simultaneously, based on a high-coherence dual-comb interferometer. With two tightly phase-locking frequency combs, we demonstrate a high-coherence dual-comb interferometer (DCI) covering 188 to 195 THz (1538.5 to 1595.7 nm) with comb-tooth resolution and a max spectral signal-to-noise ratio (SNR) of 159.7. The combination of the high-coherence dual-comb spectrometer and a reference arm simultaneously enables gas absorption spectroscopy and for the absolute distance information to be obtained in one measurement. As a demonstration, we measure the spectrum of CO and CO. From the same interferograms, we demonstrate that distance measurement, by time-of-flight (TOF), can be resolved with an rms precision of 0.53 μm after averaging 140 images and a measurement time of 1 s. Finally, we demonstrate that non-contact surface imaging, using 2D mechanical scanning, reaches lateral resolution of 40 μm. The longitudinal precision is 0.68 μm with a measurement time of 0.5 s. It verifies that DCS has the potential to be applied in standoff detection, environmental pollution monitors, and remote sensing.
在本文中，我们报告了一种基于高相干双梳干涉仪同时提供精确光谱分析和表面成像的方案。利用两个紧密锁相的频率梳，我们展示了一种覆盖188至195太赫兹（1538.5至1595.7纳米）的高相干双梳干涉仪（DCI），其具有梳齿分辨率，最大光谱信噪比（SNR）为159.7。高相干双梳光谱仪与参考臂相结合，能够在一次测量中同时实现气体吸收光谱分析和获取绝对距离信息。作为演示，我们测量了一氧化碳和二氧化碳的光谱。从相同的干涉图中，我们证明通过飞行时间（TOF）进行的距离测量，在平均140张图像且测量时间为1秒后，均方根精度可达0.53微米。最后，我们证明使用二维机械扫描的非接触表面成像横向分辨率可达40微米。纵向精度为0.68微米，测量时间为0.5秒。这验证了双梳光谱仪有潜力应用于远距离探测、环境污染监测和遥感领域。
