Application Of FPGA In High-speed Multi-channel Fiber Grating Demodulator

Fiber grating as a new kind of passive components, due to its high sensitivity, high accuracy, immunity to electromagnetic interference, has roused general concern in the sensing field. Fiber grating sensing technology based on wavelength encoding, can convert the outside temperature and stress signal to wavelength signal, and has little impact of the light source and system noise. But how to achieve high-speed, high-precision demodulation of large-scale multiplexed fiber grating sensor array has become the focus of the study of modern fiber grating sensing technology topics.This paper describes the four kinds of commonly used fiber optic grating demodulation scheme, we focused demodulation scheme based on tunable F-P filter method, and in its original demodulation method innovation, designed large-scale multi-channel fiber grating sensor system demodulation scheme. This paper described the demodulation system from the optical path of the overall program and circuit handling, analysis of the various functional components of the selected demodulation system, and completed the hardware portion of the optical fiber grating demodulation system structures and debugging, including swept light source module, precision photoelectric conversion module, FPGA signal processing circuit part. FPGA chip internal structure and processing advantages, Spartan.6FPGA chip as a signal demodulation process of a signal processing module of the controller, the use of its high-speed parallel processing capability, to achieve a32.channel fiber grating wavelength demodulation. And in the final analysis, the system is still worthy of the advanced part.