Hydrostatic pressure sensor based on gold-jacketed spherical end hollow-core photonic bandgap fibre

A hydrostatic pressure sensor based on a spherical end hollow-core photonic bandgap fibre with a length of several hundreds of micrometres is proposed. The pressure sensor head fabricated by a splicer is a micro-Michelson interferometer sensitive to the pressure due to the photoelastic effect. An experimental setup of the proposed hydrostatic pressure sensor is conducted and a linear relationship between the hydrostatic pressure and the wavelength shift of the relative reflection spectrum of the pressure sensor is presented. The pressure sensor demonstrated with a measurement range larger than 40 MPa and a sensitivity of -6.5 pm/MPa.