Hydrostatic pressure dependence of FBG inscribed in perfluorinated GI-POF

Abstract

We investigate the hydrostatic pressure dependence of the Bragg wavelength of a fiber Bragg grating (FBG) inscribed in a perfluorinated POF at 1550 nm. At 0.5 MPa, the Bragg wavelength increased with time and became almost constant ~150 min later. The pressure-dependence coefficient without considering the time constant was calculated to be 1.3 nm/MPa, which is over 5 times the values of other types of POF-FBGs. The pressure-dependence coefficient was then measured to be -0.13 nm/MPa, the absolute value of which was comparable to those of other POF-FBGs, but the sign was opposite.