分布反馈式光纤激光水听器系统中迈克尔逊干涉仪容易受外界环境温度波动影响，产生热噪声，造成解调失真。推导温度波动经激光器转化为频率噪声的理论过程，分析频率噪声与温度的关系。搭建实验测试系统，采用振动液柱法进行实验，对水听器施加800 Hz，5 V的水声振动信号，温度由室温20℃升至60℃，系统可以正常解调出水声信号；不施加水声信号，温度上升过程中每隔10℃采数，经处理在3～10 kHz频带范围内，室温20℃条件下系统的相位噪声约为-90 dB，60℃条件下相位噪声约为-70 dB，温度升高40℃导致系统相位噪声提高约20 dB。本文实验结果对后续降低系统的噪声水平具有重要意义。
The Michelson interferometer in the distributed feedback type (DFB) fiber laser hydrophone system is susceptible to temperature fluctuations in the external environment, resulting in thermal noise and demodulation distortion. The theoretical process of converting temperature fluctuations into frequency noise by laser is deduced, and the relationship between frequency noise and temperature is analyzed. Set up an experimental test system, use the vibrating liquid column method to conduct experiments, apply a 800 Hz, 5 V underwater acoustic vibration signal to the hydrophone, and the temperature rises from 20°C to 60°C at room temperature, and the system can demodulate the underwater acoustic signal normally; no underwater acoustic signal is applied. The signal is collected every 10°C during the temperature rise and processed in the frequency range of 3~10 kHz. The phase noise of the system is about –90 dB at room temperature of 20°C, and the phase noise is about –70 dB at 60°C. The temperature rises A high of 40°C leads to an increase in system phase noise of about 20 dB. The experimental results are of great significance to the subsequent reduction of the noise level of the system.
2022,44(16): 122-125 收稿日期：2021-07-30
DOI：10.3404/j.issn.1672-7649.2022.16.025
分类号：TN253
基金项目：国家自然科学基金资助项目（11774432）
作者简介：赵宏琳(1996-)，男，硕士研究生，研究方向为光纤传感技术
参考文献：
[1] 张仁和, 倪明. 光纤水听器的原理与应用[J]. 物理, 2004(7): 503–507
[2] 高学民. 光纤水听器及阵列的发展概况[J]. 光纤与电缆及其应用技术, 1996(1): 48–53
[3] KOO K P, KERSEY A D. Bragg grating-based laser sensors systems with interferometric interrogation and wavelength division multiplexing[J]. Journal of Lightwave Technology, 1995, 13(7): 1243–1249
[4] 梁迅. 光纤水听器系统噪声分析及抑制技术研究[D]. 长沙: 国防科学技术大学, 2008.
[5] 叶欣. 干涉型光纤传感器低频信号检测技术研究[D]. 长沙: 国防科学技术大学, 2010.
[6] 王力求, 王巍, 李东明, 等. 光纤水听器解调干涉仪减振降噪技术[J]. 声学与电子工程, 2012(3): 1–3+17
[7] 陈文静. 双偏振光纤干涉仪噪声与温度的影响及其抑制方法研究[D]. 哈尔滨：哈尔滨工程大学, 2019.
[8] FOSTER S. Dynamical noise in single-mode distributed feedback fiber lasers[J]. Quantum Electronics IEEE Journal of, 2004, 40(9): 1283–1293
[9] WANSER K H. Fundamental phase noise limit in optical fibers due to temperature fluctuations[J]. Electronics Letters, 1992, 28(1): 53–54
[10] FOSTER S, TIKHOMIROV A, MILNES M. Fundamental thermal noise in distributed feedback fiber lasers[J]. IEEE Journal of Quantum Electronics, 2007, 43: 378–384
[11] 李日忠. DFB光纤激光器水听器关键技术研究[D]. 武汉: 华中科技大学, 2014.
