The Fiber Bragg Grating Temperature Measurement System Based On Powerpc Research

Optical fiber grating temperature measurement is based on the principle of that the period and effective of optical fiber grating change with the outside temperature change, and then influence fiber grating reflection wavelength to commenced work. By test the change of fiber grating reflection wavelength we can calculated the change of temperature. In order to better used in the power system, we must improve the intelligence, stability and safety of the optical fiber temperature measurement system wthich based on MCU, FPGA or X86architecture. In the case, we begin to research optical fiber grating temperature measurement system base on the platform of PowerPC and do some works.First we analysis the FBG temperature sensing principle based on the coupled-mode theory, introduces the several main technology of production and packaging FBG sensors which are used now.Then, through researching and analysing the FBG wavelength demodulation technology,and determine adopt the Volume Phase Grating to beam split and InGaAs linear array detector sensitive wavelength demodulation scheme. In-depth study of the major parts of the FBG wavelength demodulation instrument, according to the selection of the appropriate module; then examined the key technical difficulties related to this demodulation scheme, including the MEMS optical switch multi-channel switch control technology,volume phase grating beam split technology, InGaAs linear array detector digital processing technology and the wavelength temperature demodulation correction technology, and proposed solutions,in order to meet the requirements of the power system security intelligent and stability.We also design the power, reset circuit, storage and communication module circuit connectivity solutions respectively to build a PowerPC platform which can be used in FBG wavelength demodulation instrument.At last there are two experiments,use the method polynomial fitting to deal with the data of the experiments.Drow out the wavelenghth-temperature curve,to study the FBG temperature sensor’s characteristics in a wide variation range of temperature, get the relationship of the wavelength-temperature conversion; verify the change status of FBG’s temperature sensitivity.