Frequency-agile dual-comb spectroscopy
Frequency-agile dual-comb spectroscopy
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DOI：
10.1038/nphoton.2015.250
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发表时间：
2016-01-01
期刊：
影响因子：
35
通讯作者：
Picque, Nathalie
中科院分区：
文献类型：
--
作者：
Millot, Guy;Pitois, Stephane;Picque, Nathalie
光谱气体传感及其应用，例如痕量检测或化学动力学，需要越来越苛刻的测量时间，采集速率，灵敏度，精度和宽调谐范围。在这里，我们提出了一种新的近红外分子光谱方法，利用先进的光通信和超连续光子学的概念。在没有锁模激光器的情况下，我们产生了两个频率梳，它们的重复频率略有不同，光谱跨度适中，但可以快速调整。频率变捷连续波激光器的输出被分割并送入两个电光强度调制器。平顶低噪声频率梳是在正常色散的非线性光纤中通过破波产生的。利用双梳状谱仪，我们以10 nm s（-1）的调谐速度，在13 μ s内记录了60 GHz的多普勒限制光谱，刷新率为80 kHz。对弱吸收的灵敏度通过长充气空心芯纤维增强。实时诊断的新机会甚至可能在实验室之外开启。
Spectroscopic gas sensing and its applications to, for example, trace detection or chemical kinetics, require ever more demanding measurement times, acquisition rates, sensitivities, precisions and broad tuning ranges. Here, we propose a new approach to near-infrared molecular spectroscopy, utilizing advanced concepts of optical telecommunications and supercontinuum photonics. We generate, without mode-locked lasers, two frequency combs of slightly different repetition frequencies and moderate, but rapidly tunable, spectral span. The output of a frequency-agile continuous-wave laser is split and sent into two electro-optic intensity modulators. Flat-top low-noise frequency combs are produced by wave-breaking in a nonlinear optical fibre of normal dispersion. With a dual-comb spectrometer, we record Doppler-limited spectra spanning 60 GHz within 13 mu s and an 80 kHz refresh rate, at a tuning speed of 10 nm s(-1). The sensitivity for weak absorption is enhanced by a long gas-filled hollow-core fibre. New opportunities for real-time diagnostics may be opened up, even outside the laboratory.