Research Of Optic-Fiber Temperature Sensor Based On Semiconductor Optical-Absorption

Temperature detection is important in modern industry and engineering. The classical temperature sensors based on electricity don't work well in some severe atmosphere as electric power system which is full of electromagnetic interference. On the contrary, the optical fiber sensors based on optics put into full play on these special occasions. The several tens of years, all kinds of optical fiber sensors develop rapidly. The optical fiber sensor based on semiconductor absorption is extensively researched, because it has the virtue of not only the merits which every optical fiber sensor has, but also low costs, simple structure, high reliability and so on.The information near the tens of years about the optical fiber temperature sensor and temperature supervise of electric power equipment is consulted and analyzed at large. A novel scheme based on optic absorption of semiconductor is proposed, which can overcome some problems at the present time. Firstly, based on the physical theory, the temperature sensitivity, light source spectrum and detector's responsibility are analyzed, the mathematical model of sensor system is built, and the design of the sensor system is discussed. By analyzing the model with matlab, we elaborate the influences to the sensor's output, which are resulted from each component and the design principle of the sensor. Secondly, we list some usual compensation processes and structures of the sensor. While their advantages and disadvantages were analyzed, a system with novel symmetrical structure is proposed and the system configuration of optical and electric portion is given. The problem of low accuracy and low stability was solved because of several measures taken in this novel system. Finally, the system for experiment is built. The experimental results show that the sensor has accuracy of 1℃over a temperature range of from 26℃to 102℃, good linearity and short response time, and meets the challenge of electric powersystem temperature detection.The paper discusses the possibility of the proposed methods, however, there are also some problems to solve, such as technological skill of detection probe, the expansion of software, further experiment, and so on.