Dual-Comb Coherent Raman Spectroscopy with near 100% Duty Cycle
Dual-Comb Coherent Raman Spectroscopy with near 100% Duty Cycle
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DOI：
10.1021/acsphotonics.0c01656
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发表时间：
2021-04-21
期刊：
影响因子：
7
通讯作者：
Goda, Keisuke
中科院分区：
文献类型：
--
作者：
Kameyama, Risako;Takizawa, Shigekazu;Goda, Keisuke
双梳相干拉曼光谱是快速探测指纹区分子振动特征的有力工具。然而，由于激光脉冲间隔（> 1ns）与分子振动相干寿命（类似3ps）不匹配，其光谱采集的占空比仅小于1%，因此其入射激光能量的>99%未被使用和浪费。在这里，我们展示了类似于100%占空比双梳相干拉曼光谱的“准”双梳源。这可以通过快速调制其中一个频率梳的腔长，并通过双色干涉测量法精确测量泵浦和探针脉冲之间的群延迟来校准样品中每个拉曼主动模式的相位。具体来说，我们使用该方法显示了创纪录的100,000光谱/s的高光谱采集速率，甚至比传统的慢速双梳相干拉曼光谱具有更高的灵敏度。
Dual-comb coherent Raman spectroscopy is a powerful tool for rapidly probing vibrational signatures of molecules in the fingerprint region. However, >99% of its incident laser energy is unused and wasted since the duty cycle of its spectral acquisition is only less than 1% due to the mismatch between the interval of the laser pulses (>1 ns) and the coherence lifetime of molecular vibrations (similar to 3 ps). Here we demonstrate similar to 100% duty-cycle dual-comb coherent Raman spectroscopy with a "quasi"-dual-comb source. This is made possible by rapidly modulating the cavity length of one of the frequency combs and accurately measuring the group delay between pump and probe pulses by two-color interferometry for calibrating the phase of each Raman active mode in the sample. Specifically, we use the method to show a record high spectral acquisition rate of 100000 spectra/s with even higher sensitivity than conventional slower dual-comb coherent Raman spectroscopy.