Miniaturized Photoacoustic Trace Gas Sensing Using a Raman Fiber Amplifier
Miniaturized Photoacoustic Trace Gas Sensing Using a Raman Fiber Amplifier
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DOI：
10.1109/jlt.2015.2443377
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发表时间：
2015-09
影响因子：
4.7
通讯作者：
R. Bauer;T. Legg;David Mitchell;G. Flockhart;G. Stewart;W. Johnstone;M. Lengden
中科院分区：
文献类型：
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作者：
R. Bauer;T. Legg;David Mitchell;G. Flockhart;G. Stewart;W. Johnstone;M. Lengden
介绍了一种最大输出功率为1.1 W的拉曼光纤放大器光源的研制及其在小型化3D打印光声光谱（PAS）甲烷痕量气体传感中的应用。拉曼放大器采用4.5 km色散位移光纤、1651 nm DFB种子激光器和商用4 W EDFA泵浦。研究了在一定频率范围内对种子激光进行高频调制，从而提高了放大器的光输出功率，降低了噪声含量，抑制了受激布里渊散射（SBS）。通过在微型3D打印气室的15.2 kHz谐振频率下对种子激光器施加第二调制，将放大器输出用作微型PAS传感器的源。对于6057 cm-1处的目标甲烷吸收线，表征了传感器系统性能和SBS抑制的影响，导致对于130 s的信号采集时间的17 ppb甲烷的检测限（1σ），系统的归一化噪声等效吸收系数为4.1 · 10-9 cm-1 W Hz-1/2。
This paper presents the development of a Raman fiber amplifier optical source with a maximum output power of 1.1 W centered around 1651 nm, and its application in miniaturized 3D printed photoacoustic spectroscopy (PAS) trace gas sensing of methane. The Raman amplifier has been constructed using 4.5 km of dispersion shifted fiber, a 1651 nm DFB seed laser, and a commercial 4 W EDFA pump. The suppression of stimulated Brillouin scattering (SBS) using a high-frequency modulation of the seed laser is investigated for a range of frequencies, leading to an increase in the optical output power of the amplifier and reduction of its noise content. The amplifier output was used as the source for a miniature PAS sensor by applying a second modulation to the seed laser at the resonant frequency of 15.2 kHz of the miniature 3D printed gas cell. For the targeted methane absorption line at 6057 cm-1, the sensor system performance and influence of the SBS suppression is characterized, leading to a detection limit (1σ) of 17 ppb methane for a signal acquisition time of 130 s, with a normalized noise equivalent absorption coefficient of 4.1 · 10-9 cm-1 W Hz-1/2 for the system.