Hydrostatic pressure sensors based on ultrashort distributed-Bragg-reflector fiber lasers

Abstract

We propose and demonstrate, for the first time to our knowledge, simple hydrostatic pressure sensors based on ultrashort dual-polarization distributed-Bragg-reflector fiber lasers. A bare polarimetric laser is used directly to measure the high fluid pressure up to 20 MPa. By detecting the polarization beat signal change generated from the two orthogonal polarization modes in the laser, a 0.42-MHz/Mpa pressure sensitivity and ~5-kPa resolution are achieved. For effectively enhancing the pressure sensitivity, we also exhibit a simple and accurate low-pressure sensor by designing a structure to convert the external pressure to the lateral force on the laser. This sensor shows significant and considerably high sensitivity to hydrostatic pressure of 69.2 MHz/kPa, which is almost 5 orders of magnitude higher than that of a sensor via bare lasers.