Temperature-insensitive fiber-optic tip sensors array based on OCMR for multipoint refractive index measurement

Abstract

A temperature-insensitive fiber-optic tip sensors array is proposed for multipoint refractive index measurement using optical carrier based on microwave reflection (OCMR). The tip sensors array is made of a series of cleaved fiber end-faces and is spatially multiplexed by physically connecting with a fiber-optic splitter with different lengths of short delay fiber. A sensors array with eight sensing tips is demonstrated for multipoint refractive index measurement. Experimental results show that it can offer a high refractive-index resolution of 3.60 × 10-6 RIU and a low temperature-refractive index cross sensitivity of 3.74 × 10-7 RIU/°C. Such a sensors array not only possesses excellent sensing performances, but also can be integrated into a chip for biochemical sensing applications.