Influence of frequency shift of pump laser on photoacoustic signal for frequency stabilization

Guo Xiaoyang; Li Ting; Wang Du; Zhong Zheqiang; Meng Qinglong; Zhang Bin

The frequency stability of CO2 pumping laser is of great importance for optically pumped terahertz(THz) gas laser. Aimed at frequency stabilization technique based on photoacoustic effect, the influence of detective conditions on the detection of weak photoacoustic signal in photoacoustic cell was theoretically analyzed and numerically simulated and the detective conditions were further optimized for high-precision detection of photoacoustic signal, including the pressure of methanol gas and the microphone sensitivity. On the basis, the variation of photoacoustic signal with the frequency shift of the pump laser from the center of the absorption line was analyzed. The results show that the low pressure condition and highly sensitive microphone are the keys for achieving high-precision photoacoustic frequency stabilization. When the laser frequency of CO2 pumping laser shifts from the center of the absorption line, the cavity length can be adjusted accurately by the regulation of feedback photoacoustic signal to ensure the frequency stability of output laser, and the frequency shift could be controlled within the magnitude of megahertz.

1. College of Electronics and Information Engineering,Sichuan University,Chengdu 610064,China;

2. Research Center of Laser Fusion,China Academy of Engineering Physics,Chengdu 610041,China;

3. Terahertz Research Center,China Academy of Engineering Physics,Mianyang 621900,China

Received Date: 2014-10-08

Rev Recd Date: 2014-11-20

Publish Date: 2015-06-25

Key words:

frequency stability based on photoacoustic effect /
frequency shift /
pumping laser /
optically pumped terahertz(THz)gas laser /
detective conditions

Abstract: The frequency stability of CO2 pumping laser is of great importance for optically pumped terahertz(THz) gas laser. Aimed at frequency stabilization technique based on photoacoustic effect, the influence of detective conditions on the detection of weak photoacoustic signal in photoacoustic cell was theoretically analyzed and numerically simulated and the detective conditions were further optimized for high-precision detection of photoacoustic signal, including the pressure of methanol gas and the microphone sensitivity. On the basis, the variation of photoacoustic signal with the frequency shift of the pump laser from the center of the absorption line was analyzed. The results show that the low pressure condition and highly sensitive microphone are the keys for achieving high-precision photoacoustic frequency stabilization. When the laser frequency of CO2 pumping laser shifts from the center of the absorption line, the cavity length can be adjusted accurately by the regulation of feedback photoacoustic signal to ensure the frequency stability of output laser, and the frequency shift could be controlled within the magnitude of megahertz.

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Reference (21)

[1]	Wang Ruijun, Wang Hongqiang, Zhuang Zhaowen, et al. Research progress of terahertz radar technology[J]. Laser Optoelectronics Progress, 2013, 50(4): 040001. (in Chinese) 王瑞君, 王宏强, 庄钊文, 等. 太赫兹雷达技术研究进展[J]. 激光与光电子学进展, 2013, 50(4): 040001.
[2]
[3]	Mueller E R, Henschke R, Robotham Jr W E, et al. Terahertz local oscillator for the microwave limb sounder on the aura satellite[J]. Applied optics, 2007, 46(22): 4907-4915.
[4]
[5]	Mueller E R, Robotham Jr W E, Meisner R P, et al. 2.5 THz laser local oscillator for the EOS Chem 1 satellite[C]//Proceedings of the Ninth International Symposium on Space Terahertz Technology, 1998: 563-574.
[6]
[7]	Yuan Dandan, Hu Shuling, Liu Honghai, et al. Research of laser frequency stabilization[J]. Laser Optoelectronics Progress, 2011, 48(8): 081401. (in Chinese) 苑丹丹, 胡姝玲, 刘宏海, 等. 激光器稳频技术研究[J]. 激光与光电子学进展, 2011, 48(8): 081401.
[8]
[9]	Rosensweig A. Photoacoustic and Photoacoustic Spectroscopy[M]. Beijing: Science Press, 1986. (in Chinese) 罗森威格A. 光声学和光声谱学[M]. 北京: 科学出版社, 1986.
[10]
[11]	Chen Jiabi. Laser Principles and Applications[M]. Beijing: Publishing House of Electronics Industry, 2004. (in Chinese) 陈家壁. 激光原理及应用[M]. 北京: 电子工业出版社, 2004.
[12]
[13]	Zhang Zebo, Zhu Wensen, Zhao Yuying, et al. Opto-acoustic frequency stabilization of a CW CO_2 laser[J]. Applied Laser, 1984, 6: 011. (in Chinese) 张泽渤, 朱文森, 赵玉英, 等. CW CO_2 激光器的光声稳频[J]. 应用激光, 1984, 6: 011.
[14]
[15]
[16]	Wang W J, Lin R M, Zou Q B, et al. Modeling and characterization of a silicon condenser microphone[J]. Journal of Micromechanics and Microengineering, 2004, 14(3): 403.
[17]
[18]	Wang Wei, Dong Jian, Ji Shiming. Design and simulation of micromachined silicon condenser microphone with free floating diaphragm[J]. Journal of Transduction Technology, 2009(11): 1571-1575. (in Chinese) 王伟, 董健, 计时鸣. 具有自由悬浮敏感膜的硅微机械电容式麦克风的设计与仿真计算[J]. 传感技术学报, 2009(11): 1571-1575.
[19]
[20]	Xu Xuemei, Dai Peng, Yang Bingchu, et al. Duffing photoacoustic cell weak signal detection amplitude duffing[J]. Acta Physica Sinica, 2013, 62(20): 204303. (in Chinese) 许雪梅, 戴鹏, 杨兵初, 等. 光声池中微弱光声信号检测[J]. 物理学报, 2013, 62(20): 204303.
[21]	Yu Xiao. Study on the control system of TEA CO_2 laser cavity[D]. Wuhan: Huazhong University of Science and Technology, 2009. (in Chinese) 喻筱. TEA CO_2 激光器腔长控制系统研究[D]. 武汉: 华中科技大学, 2009.

Influence of frequency shift of pump laser on photoacoustic signal for frequency stabilization

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