Abstract: It presents the design of one type of fiber grating sensor system of adjustable sensitivity with equal intensity via the use of fiber bragging grating as the sensitive components.The traditional sensor structure which had a sensor chip of fixedlength was changed to one with a chip of changeable length. The length of the cantilever sensor chip can be changed in this system, and the effect of the sensitivity adjustment can be achieved. The theoretical analysis and results of vibration and displacement experiments show that the sensor structure is able to achieve the effect of sensitivity adjustment, so it has a wide adjustable sensitivity range.

Key words: fiber sensor；fiber bragg grating (FBG)；sensitivity adjustable sensor；vibration sensor；displacement sensor