Frequency-stepped pulse train generation in an amplified frequency-shifted loop for oxygen A-band spectroscopy
Frequency-stepped pulse train generation in an amplified frequency-shifted loop for oxygen A-band spectroscopy
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用于氧气 A 波段光谱的放大频移环路中的频率步进脉冲序列生成
DOI：
10.1364/oe.26.034753
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发表时间：
2018-12-24
期刊：
影响因子：
3.8
通讯作者：
Shu, Rong
中科院分区：
文献类型：
--
作者：
Chen, Tao;Kong, Wei;Shu, Rong
我们展示了一种频率步进脉冲串 (FSPT) 生成系统，可在时域中实现直接氧 A 波段光谱。 FSPT 是通过在放大频移环路 (AFSL) 中循环大约 1529.5 mu 的初始单频脉冲而形成的。在此配置中，可以生成频率间隔为 200 MHz 的具有多达 80 个等距光频率的 FSPT。然后，FSPT 的基本波长倍频至类似于 764.75 nm，覆盖氧 A 波段的一个吸收峰，用于光谱学原理验证实验。基于 FSPT 的差分吸收测量得到的氧气透过率曲线与 HITRAN 数据库的计算结果非常吻合。对于 1 atm 的清洁空气，测量结果和计算结果之间的均方根误差分别为 0.68% 和 0.55%。分别为 1.5 个大气压和 1.5 个大气压。通过选择适当的增益介质或通过非线性频率转换，可以进一步扩展这种 FSPT 的波长，以匹配各种气体的吸收线，从而使基于 FSPT 的光谱学成为痕量气体遥感的有希望的候选者。 (C) 2018 年美国光学协会根据 OSA 开放获取出版协议条款
We have demonstrated a frequency-stepped pulse train (FSPT) generation system enabling direct oxygen A-band spectroscopy in the time domain. The FSPT is formed by circulating the initial single-frequency pulses at similar to 1529.5 mu in an amplified frequency-shifted loop (AFSL). An FSPT with up to 80 equidistant optical frequencies can be generated with a frequency spacing of 200 MHz in this configuration. The fundamental wavelength of the FSPT is then frequency doubled to similar to 764.75 nm, covering one absorption peak in oxygen Aband, for the proof-of-principle experiment in spectroscopy. The oxygen transmission curves retrieved from FSPT-based differential absorption measurement am in good agreement with the calculated results from HITRAN database. The root-mean-squared errors between the measured and calculated results are 0.68% and 0.55% for clean air at 1 atm. and 1.5 atm., respectively. The wavelength of such an FSPT can be further extended to match the absorption lines of various gases by selecting proper gain media or through nonlinear frequency conversion, thereby making the FSPT-based spectroscopy a promising candidate for trace-gas remote sensing. (C) 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement