Refractive index sensor based on measuring the transmission power of tilted fiber Bragg grating

A low-cost, compact and practical method to measure the surrounding refractive index (SRI) is proposed by measuring the transmission power of the tilted fiber Bragg grating (TFBG). The transmission power of the TFBG is detected when the SRI varies from 1.3723 to 1.4532; the power decreases monotonously from −2.14 dBm to −3.26 dBm. Under this condition, the resolution of the refractive index of TFBG is predicted to be 10−4 and the resolution of the concentration of the solution is as slight as 0.01%. Considering its simple configuration and high stability, this way is potential to monitor physical, chemical and biological parameters in the natural environments.