论文标题
11μs的时间分辨，连续的双弯曲光谱与光谱过滤模式锁定频率梳子
11-μs Time-resolved, Continuous Dual-Comb Spectroscopy with Spectrally Filtered Mode-locked Frequency Combs
论文作者
论文摘要
基于便携式锁定的纤维频率梳子的宽带双弯曲光谱（DC）是原位，无校准的多物种光谱的强大工具。尽管使用模式锁定DC的单个频谱的采集通常将微秒降至毫秒到毫秒，但这些光谱仪的应用通常仅限于系统和过程中，由于需要平均许多光谱达到高信噪比（SNR）的平均频谱，因此时间变化秒或分钟。在这里，我们演示了高速，连续的，纤维模式的激光DC，降低到11 $μ$ S的时间分辨率。我们通过使用便携式Fabry-Perrot腔过滤梳光谱来实现这一目标，从而用1 GHz牙齿间距产生过滤后的梳子。 1 GHz间距可提高给定光学带宽的DCS采集速度和SNR，同时保留足够的间距以在各种条件下解决吸收特征。在整个16毫秒压缩周期中，我们用133 cm $^{ - 1} $带宽（4000梳子齿）和1.4 ms的时间分辨率在整个16毫秒压缩循环中测量甲烷的光谱，并通过光谱过滤其中一个梳子。通过过滤两个梳子，我们测量了一个单一的25厘米$^{ - 1} $（750梳子齿）CO的频谱左右6330 cm $^{ - 1} $，in 11 $μ$ s。该技术可以同时进行高速和高分辨率DCS测量，并且可以在稳健和便携式纤维模式锁定频率梳子的八度跨度范围内应用。
Broadband dual-comb spectroscopy (DCS) based on portable mode-locked fiber frequency combs is a powerful tool for in situ, calibration free, multi-species spectroscopy. While the acquisition of a single spectrum with mode-locked DCS typically takes microseconds to milliseconds, the applications of these spectrometers have generally been limited to systems and processes with time changes on the order of seconds or minutes due to the need to average many spectra to reach a high signal-to-noise ratio (SNR). Here, we demonstrate high-speed, continuous, fiber mode-locked laser DCS with down to 11 $μ$s time resolution. We achieve this by filtering the comb spectra using portable Fabry-Perot cavities to generate filtered combs with 1 GHz tooth spacing. The 1 GHz spacing increases the DCS acquisition speed and SNR for a given optical bandwidth while retaining a sufficient spacing to resolve absorption features over a wide range of conditions. We measure spectra of methane inside a rapid compression machine throughout the 16 ms compression cycle with 133 cm$^{-1}$ bandwidth (4000 comb teeth) and 1.4 ms time resolution by spectrally filtering one of the combs. By filtering both combs, we measured a single-shot, 25 cm$^{-1}$ (750 comb teeth) spectrum of CO around 6330 cm$^{-1}$ in 11 $μ$s. The technique enables simultaneously high-speed and high-resolution DCS measurements, and can be applied anywhere within the octave-spanning spectrum of robust and portable fiber mode-locked frequency combs.
