Amplified frequency double-shifting loop enabled frequency-stepped pulse train for direct time domain CO2 measurement
Amplified frequency double-shifting loop enabled frequency-stepped pulse train for direct time domain CO2 measurement
复制标题
放大频率双移环路启用频率步进脉冲序列，用于直接时域 CO2 测量
DOI：
10.1364/josab.425720
复制
发表时间：
2021-10-01
影响因子：
1.9
通讯作者：
Shu, Rong
中科院分区：
文献类型：
--
作者：
Chen, Xin;Chen, Tao;Shu, Rong
We have developed an amplified frequency double-shifting loop with a bidirectionally operated acousto-optic modulator as the in-loop frequency shifter to generate a frequency-stepped pulse train (FSPT) with frequency spacing twice as much as its operation frequency. Based on this configuration, a FSPT with 51 equidistant optical frequencies and 800 MHz frequency spacing around 1572 nm was generated, covering the whole R16 absorption peak of CO2 for direct spectral measurement in the time domain. The retrieved transmission curve from a CO2 gas cell with concentration of 4.02% is in good agreement with the calculated Voigt lineshape from the HITRAN database. The maximal relative errors between the measured and calculated results are within 0.5% for each optical frequency, indicating its great potential for practical CO2 monitoring.
