Fiber laser hydrophones have got widespread concerns due to the unique advantages and broad application prospects. In this paper, the research results of the eight-element multiplexed fiber laser acoustic pressure array and the interrogation system are introduced, containing low-noise distributed feedback fiber laser (DFB-FL) fabrication, sensitivity enhancement packaging, and interferometric signal demodulation. The frequency response range of the system is 10 Hz-10 kHz, the laser frequency acoustic pressure sensitivity reaches 115 dB re Hz/Pa, and the equivalent noise acoustic pressure is less than 60μPa Hz^1/2. The dynamic range of the system is greater than 120 dB.

介绍了一种光纤光栅应变传感系统在船舶结构监测中的应用。首先设计了贴片式的光纤光栅应变传感器，采用无胶化封装，具有良好的线性和重复性。然后搭建了基于非平衡MZ干涉仪的PGC解调系统，实现了船体应变信号的高精度实时解调。最后介绍了传感器的施工工艺和流程，并对传感系统采集到的结构应变数据进行了分析。研究成果对光纤光栅应变传感系统在船舶结构监测中的推广应用具有工程指导意义。

地埋式入侵监测系统具有隐蔽性强、受自然因素影响小、误报率低、识别概率高等特点, 在入侵监测中具有重要作用。介绍了将光纤传感用于入侵监测的主要技术方案, 阐述了光纤分布式振动传感(DVS)系统和光纤布拉格光栅(FBG)振动传感系统的工作原理。对这两种系统进行了人员入侵监测实验。结果表明, DVS系统的有效探测范围可达到10~15 m, 空间分辨率约为20 m; FBG振动传感系统的最大有效探测距离超过75 m。对比和评估了这两种系统的关键性能, 展望了地埋式光纤入侵监测系统的应用方向。

基于光纤光栅传感理论设计了一种应用于周界安防的低频振动传感器。采用商用解调仪OPD4000对传感器的灵敏度进行了测试, 在10~100Hz频率范围内, 传感器灵敏度高于1000pm/g。基于非平衡迈克尔逊干涉仪相位载波调制（PGC）解调技术搭建了一套光栅传感器解调系统, 实现对传感器低频振动信号的高精度实时解调, 使得该系统可广泛应用于机场、监狱、油库、核场所等重要区域的周界安防中。

A high-performance compact vibration sensor based on fiber Bragg grating (FBG) is designed. The acceleration sensitivity of the FBG vibration sensor is measured to be larger than 30 pm/g. From 10 Hz to 250 Hz, a quite flat frequency-response curve can be obtained with additional damping, which suppresses the resonance peak effectively. A phase-generated carrier (PGC) demodulation technique realized by compact reconfigurable input and output (RIO) system is applied in our sensing system.

介绍了在相位掩模板法制作光纤光栅的过程中，通过测量和调节光纤在拉直状态下所承受的拉力，从而精确控制光栅布拉格波长的光纤光栅制作方法。利用此方法，可使光纤光栅的波长制作误差控制在±0.05 nm以内，并利用一定周期的相位掩模板制作5 nm波长范围内的任意波长的光纤光栅，极大地提高了相位掩模板法制作技术的效率和灵活性。同时，提出了利用扫描曝光技术，在光纤光栅刻写过程中持续改变光纤拉力，制作啁啾光纤光栅的新方法。

A short distributed feedback fiber laser with a nearly unidirectional output is fabricated and tested. The short fiber laser is made of a polarization-dependent phase-shift grating fabricated with a vertically polarized 244-nm ultraviolet (UV) laser. A single \pi phase-shift is introduced to a 2-cm grating at a specified position by directly moving the phase mask during UV beam scanning. Test results show that the laser has a single polarization longitudinal mode with 2.6-mW pump threshold. The backward-to- forward output power ratio is approximately 30:1. The relative intensity noise is –88 dB/Hz, and the linewidth is approximately 10 kHz at 75-mW 980-nm pumping. The unidirectional output and short dimension of this short fiber laser make it very useful in sensing applications, especially in multiplexed sensing applications.