Fiber Bragg grating-based hydraulic pressure sensor with enhanced resolution

This paper reports a simple technique for hydraulic pressure measurement with enhanced resolution using a fiber Bragg grating (FBG) and a metal spring which acts as transducer. The sensor works by means of measuring the Bragg wavelength shift of FBG caused by the longitudinal elongation of optical fiber due to applied pressure. Experimental results show that the sensor possesses good linearity and repeatability in pressure measurement ranging over 0 to 55 bar, with a sensitivity of 57.7 pm∕bar. A wavelength-intensity interrogation scheme using single-multiple-single-mode fiber structure is designed for FBG sensor, which enabled the system to be compact, lightweight, inexpensive, and high resolution. © 2015 Society of Photo-Optical Instrumentation Engineers (SPIE) (DOI: 10.1117/1.OE.54.9.096104)