基于光声光谱法的光纤气体传感器研究

论述了光声光谱信号的产生。提出用光纤相位传感器代替传统的微音器检测光声信号 ,讨论了光纤中光波的相位变化与光声信号的关系。设计了光学长程结构 ,有效增加了对光功率的吸收。用染料激光器作光源对SO2气体浓度进行测量。实验表明 ,最低检测灵敏度可达 1 2× 10 -10 。由于采用光谱技术与光纤技术相结合 ,使研制的传感器具有较高的灵敏度 ,信号的传输通道具有强的抗电磁干扰及防燃防爆能力。气体探头体积小 ,响应速度较快。信号处理电路具有较强的抑制噪声干扰能力。该传感器及其系统在灵敏度、精度、响应时间等性能指标上达到了检测气体含量要求

Study on Optical Fiber Gas Sensor Based on Photoacoustic Effect

The theory of photoacoustic spectrum is presented briefly in this paper. The optical fiber phase sensor is used to replaces traditional microphone, and the relationship between light phase and photoacoustic signal is discussed. Multiple-reflection system is used to enhance absorption effectively. The dye laser is used as light source to measure SO2 gas concentration. It shows that the sensitivity of 1.2×10-10 can be obtained. The combination of spectrum technology and optical fiber technology provides higher sensitivity, stronger ability to resist electromagnetic interference, avoiding fire and explosion. The gas probe has small volume, relatively fast response speed. The signal processing circuit has high ability to suppress noise interference. The experiments show that the sensor and its system match the requests of sensitivity, accuracy, and response time in detecting the gas concentration.