Design The FBG Demodulator Based On SingleChip Microcontroller System

Fiber sensor is developed with the technology of fiber communication since 1970's. FBG sensor is a new type of fiber sensor. And it is one of the current heat research fields in the optical fiber grating sensor technique fields. It is widely applied in many fields, demodulation technique of the FBG sensor is currently a critical and difficult problem in nowadays FBG sensoring technique fields. Although a large number of researchers in domestic research field 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.The fiber grating sensor theory and the demodulation technology is systematically researched in this paper. The main content includes: the principle of fiber grating sensor;the analysis of several technologies of demodulation and the F-P filter demodulation is introduced in detail;the design of demodulation system based on SingleChip system.Firstly, the recent developments in the area of optical fiber grating sensors are reviewed. The method of fiber grating fabrication is introduced briefly.The demodulation method of fiber grating is the key technology of fiber grating sensor. The main demodulation method includes: grating matching method, tunable Fabry-Perot cavity method, non-balance Mach-Zehnder interferometer method, Michelson interferometer method and tunable narrow-band light source method. The tunable Fabry-Perot cavity method is discussed in detail, and a demodulation system based on SingleChip system is put forward.SingleChip Microcontroller, a kind of highly integrated micro-computer, is especially designed for controlling and intelligent machines. It has very powerful controlling function, low price, and excellent reliability. SingleChip Microcontroller has enough instruction system to divide and transfer the orders, logic practice of the I/O port and has the function of bit manipulation. SingleChip Microcontroller can satisfy the requirement of industrial control. In order to improve the processing speed and precision of the instrument, I have designed a fiber grating system, which is based on double ATMEL 89C52 8-bit SingleChip Microcontroller. This article documents the detailed methodology of designing both hardware and software, and data-processing methodology as well. It is worth mentioning that the instrument designed by me has already been put into practice.