Dual transverse fiber tip Fabry-Perot cavities for simultaneous measurements of pressure and temperature

A fiber tip sensor based on dual transverse Fabry-Perot (FP) cavities for simultaneous temperature and gas pressure measurements is proposed, fabricated and tested. The proposed fiber tip sensor is formed by one-step polishing the end face of a microstructure fiber, which contains a hollow hole in the center and an eccentric core, to 45-degrees. The hybrid fiber tip sensor consists of a quartz cavity and a gas cavity effectively solving the problem of cross sensitivity in dual-parameter sensors. By tracking the shift of the interference spectra of the two FP cavities, simultaneous measurements of temperature and pressure is achieved. With advantages of a compact structure, high spatial resolution, simple fabrication and ability of multi-parameter detection, the sensor is suitable for use in a high temperature and high-pressure simultaneous sensing applications. Furthermore, the fabrication approach ensures consistent size of the FP cavities, making the sensor suitable for mass production.