A high sensitive FBG pressure sensor using thin metal diaphragm

A high sensitive pressure sensor using fiber Bragg grating (FBG), integrated with thin metal diaphragm is designed and investigated both theoretically and experimentally. Under pressure the diaphragm deflection causes an axially stretched-strain along the length of the FBG. The pressure sensitivity of the sensor gained from the test results is 2.05 × 10−2 MPa−1, approximately four orders of magnitude higher than that can be measured with the bare FBG. Experimental results showed good agreement with the proposed theoretical results.