Simultaneous Strain and Temperature Measurement With Fiber Bragg Grating and Multimode Fibers Using an Intensity-Based Interrogation Method

A new all-fiber sensor capable of simultaneous measurement of strain and temperature is presented. The sensor system is formed by a fiber Bragg grating and two sections multimode fibers (MMFs). One section of the MMF is isolated from strain and acts as a temperature-dependent edge filter, while the other is isolated from both strain and temperature changes. By monitoring the optical power changes, it is feasible to obtain information that permits simultaneous measurement of strain and temperature with a low-cost and simple structure.