Gas Gas Detection Fiber Comb Filter

Optical fiber gases sensing technology is a novel discipline, which has a wide applicable prospect in industrial production, environment monitoring and medical science. In recent years, with the development of optical fiber sensing technology, the research of optical fiber gas sensors has been seriously regarded all over the world. The signal detected by optical fiber gas sensors is carried by light wave, which has a small interference on surroundings. With their qualities of no electricity on sense organ and blast proof in essence, they can be used as on-line detection of flammable and exploding gases in industry.In this paper, methane is used as a research sample. The paper designs an all optical-fiber gas monitor system based on near-infrared absorption spectrum method. The system can be used in real-time measurement of the methane gas. By analyzing and comparing with many gas measure methods and according to the need of measure precision and work condition of the system, we choose spectrum absorption method as the theoretical method. After studying near-infrared selectivity absorption theory of the gas and methane gas absorption spectrum in near-infrared field, considering about the attenuation characteristic of the transport optical fiber, the strong absorption spectrum of methane gas is confirmed. Using SLED as the light source, spectrum absorption method as the theoretical principle, combined with the multiple beam interference and interrelated theories, we design an all-optical fiber F-P interleaver which enhance the sensitivity and achieve the measure of the consistency of the methane gas.During the development of this project, the author has been mainly engaged in the task of theoretic research, scheme design and feasibility analysis for gas concentration detection. Implementation of detection circuit and experiment of theoretic demonstration are achievements of the whole research group. The author has assisted the research group leader to complete many positive assignments. From the starting involvement to material finding and system model design, the author holds an opinion that optical fiber gas concentration detection relates to multidisciplinary knowledge. In order to develop a better detection system, there are still a lot of practical works to accomplish. The present paper advances the basic system model of methane gas concentration detection. It has played a solid foundation and provided a valuable reference for the research of high-performance optical fiber gas sensor in the future.