Hydrostatic pressure sensor based on fiber Bragg grating written in single-ring suspended fiber

We present a novel optical fiber consisting of a suspended-fiber with core and cladding diameter of similar to 5 and 30 mu m and a supporting ring with thickness of similar to 9 mu m. The outer diameter of the fiber was 125 mu m and a fiber Bragg grating (FBG) with a length of 1-mm was inscribed on it. Hydrostatic pressure was measured by monitoring the Bragg wavelength shifts of 9-mm long single-ring suspended fiber. Pressure sensitivity was measured to be 18.92 pm/MPa, which is about five times higher than FBG on standard single-mode fiber.