The Study On The Fiber Bragg Grating Demodulation System Based On Infrared CCD

Optical fiber grating is a kind of optical fiber passive device. It has been developed quickly and widely used in recent years. For it's many unique merits, it has great application prospective in optical fiber communication and optical sensor field and so on. Optical fiber grating sensors based on optical fiber grating technology have become the focus in sensors study field. The demodulation technique of the FBG is currently a critical and difficult problem in nowadays.How to design a high-sensitivity, multiplexed-detection and low-cost system becomes the hot-topic in the study on FBG sensing system. Although a large number of researchers in domestic research units have been doing a lot of research and investigations on the demodulation methods of FBG, most of the researches are still in the phase of lab experiments and have not yet met the requirements of the practical industrial mass productions.Firstly, the recent developments in the area of fiber grating sensors are reviewed.The problems about it in our country are also indicated. The general principles in demodulation of FBG sensing signal are discussed and mainly focus on their principles, performances and characteristics. The main demodulation method includes: filter, interferometer, tunable light source, fiber grating dispersion techniques. The typical schemes are displayed and their advantages and weaknesses are analyzed and discussed. Moreover, the main technical problems in signal demodulation of FBG which provides foundation for the design of the system are summarized.Then, a new fiber Bragg grating demodulation method based on infrared CCD is put forward and a sensor demodulation experimental system is established in this paper. The driver timing and signal processing methods of the infrared CCD are emphatic introduced. The driver timing is simulated by VHDL language and MAX+PLUS II software. The data acquisition software is designed and real-time monitoring data is realized.When the test system is set up and the data acquisition software is accomplished, temperature demodulation experiment is done to validate this solution. The tests indicate that the whole system has an excellent accuracy and reliability. The feasibility of the system used in engineering is verified in specific projects. At last, summarize the dissertation and anticipate the future research works based on the results of experiments.