In this paper, a design of demodulation system applied to Fiber Bragg Grating sensor will be illustrated. This system is
based on the principle of Fiber Bragg Grating strain sensing; therefore this applied system has the following
characteristics: high sensitivity, high precision, low cost and so on.
Demodulation system bases on the traditional matching method, and uses the two matched Fiber Bragg Grating parallel
mode. Just because of this, it improves on a certain extent compared with the traditional one. The two Fiber Bragg
Gratings are pasted on Hollow Aluminum Cantilever respectively so as to realize the high precision and the large scale
This paper proves the following theory through the academic analyses and experimentation, that is: pasting Fiber Bragg
Grating on Hollow Aluminum Cantilever can improve the response sensitivity. During the process of matching,
increasing the load on the Hollow Aluminum Cantilever, when the qualities of load cannot beyond the limited quality,
there is a good linearity relation between the change of load's quality and the change of wavelength. The limited quality
comes from the experimentation. The experimentation proves that the structure of two matched Fiber Bragg Grating
parallel can increase the range of strain which can be measured largely, and at the same time this structure can solve
double-value problem which exists in the ordinary matching method. The strain sense signal through the two parallel
demodulation Fiber Bragg Gratings into data processing circuit. The single chip processes the data from the data
processing circuit and works out the strain which is detected by Fiber Bragg Grating sensor.