光纤气体传感器光源温控问题的研究

光谱吸收型光纤气体传感器中,利用气体分子的吸收光谱,采用分布反馈式半导体激光器(DFB LD)作为光源,使光源输出中心波长精确对准气体的吸收峰,从而来检测出气体的浓度.而要使测量准确,光源的温控非常重要.提出了一种光源两级温控的思想:外壳温控和结温控制,并设计了温控电路,温控实验证明了两级温控的有效性.

Study on Temperature Controlling of Light Source for Optical Fiber Gas Sensor

Each kind of gas has absorptive near-infrared spectra,if a light source's center wavelength is locked on the gas's absorptive spectrum peak,then absorption will happen,the output light intensity decrement is related to the gas's concentration,so we analyze the output light,we will know the concentration.Distributed feedback laser diode(DFB LD) is used as a light source.Experiments show that the changing of DFB LD surface and kernel temperature will affect directly the light source's center wavelength and make measurement impossible.A two-level temperature controlling idea is brought forward;and its corresponding circuits are also given.The two-level temperature controlling is controlling DFB LD surface temperature and kernel temperature.Temperature controlling experiments prove this idea is right and the circuits are effective.