Simultaneous strain and temperature measurements with fiber Bragg grating written in novel Hi-Bi optical fiber

A fiber Bragg grating (FBG) was written in a novel "quasi-rectangle" high birefringence fiber by the phase-mask method. Two Bragg wavelengths corresponding to the fast-axis mode and slow-axis mode are observed in this grating, and a wavelength splitting as large as 0.765 nm was obtained. The wavelength splitting changes proportionally to the temperature, but remains the same as the strain increases. This novel FBG can be used to measure temperature and strain simultaneously.