[1] [1] Xu Mengrong, Sun Yuan, Wang Tongquan, et al. Application effect analysis of high power laser atmospheric transmission[C]7th Symposium on Novel Photoelectronic Detection Technology Applications, 2021: 11763.

[2] Huang Yinbo, Wang Yingjian. Effect of the measurement errors of atmospheric parameters on the laser propagation effects[J]. High Power Laser and Particle Beams, 18, 720-724(2006).

[3] Li Zhe, Zhang Zhirong, Sun Pengshuai, . Multi-point full range monitoring of methane based on TDLAS technology[J]. Infrared and Laser Engineering, 46, 0917009(2017).

[4] Yuan Zihao, Huang Yinbo, Lu Xingji, et al. Measurement of CO₂ by wavelength modulated reinjection off-axis integrated cavity output spectroscopy at 2 μm[J]. Atmosphere, 12, 1247(2021).

[5] Du Zhenhui, Zhang Shuai, Li Jinyi, et al. Mid-infrared tunable laser-based broadband fingerprint absorption spectroscopy for trace gas sensing: A review[J]. Applied Sciences, 9, 338(2019).

[6] Sun Liqun, Zou Mingli, Wang Xuan, . Application of tunable diode laser absorption spectroscopy in breath diagnosis[J]. Chinese Journal of Lasers, 48, 1511001(2021).

[7] Jia Liangquan, Qi Hengnian, Hu Wenjun, . CO₂ concen-tration detection system for seed respiration[J]. Optics and Precision Engineering, 27, 1397-1404(2019).

[8] Kishore K, Akbar A S. Evolution of lock-in amplifier as portable sensor interface platform: A review[J]. IEEE Sensors Journal, 20, 10345-10354(2020).

[9] Zhang Cheng, Liu Huan, Ge Jian, et al. FPGA-based digital lock-in amplifier with high-precision automatic frequency tracking[J]. IEEE Access, 8, 123114-123122(2020).

[10] Chen Xinda, Wei Minxiang, Chen Kai, et al. Research on weak signal detection of integral average digital lock-in amplifier[J]. Measurement Science and Technology, 32, 105905(2021).

[11] Liu Huifang, Li Bin, He Qixin, . Development of a digital orthogonal lock-in amplifier and its application in methane detection[J]. Acta Photonica Sinica, 45, 0423004(2016).

[12] Guo Tiantai, Cui Chenchen, Kong Ming, . Design of gas detection system based on FPGA[J]. Applied Laser, 38, 829-834(2018).

[13] [13] Chighine A, Fisher E, Wilson D, et al. An FPGAbased lockin detection system to enable Chemical Species Tomography using TDLAS[C]2015 IEEE International Conference on Imaging Systems Techniques (IST), 2015: 15.

[14] Zhu Guojun, Zhang Hao, Zhang Zhijun. Implementation of CIC filter based on FPGA[J]. Electronic Science and Technology, 19-22(2006).

[15] [15] Gao Yajun. Digital Signal Processing Based on FPGA[M]. 2nd ed. Beijing: China Industrial Infmation Publishing Group, 2015. (in Chinese)

[16] Rao Zhiqiang, Ye Nianyu. Inquisition and realization of digital wave filter based on FIR DF and IIR DF[J]. Computer & Digital Engineering, 33, 143-146(2005).