Simultaneous temperature and ammonia detection in water by tin-dioxide optoelectronic sensor

In this work, a fiber optic multifunction sensing system is presented. Fiber Bragg grating (FBG) technology is integrated with a thin film refractometric system in order to retrieve simultaneous measurements of temperature and ammonia concentration in water. The sensing probe is fabricated by depositing a tin dioxide (SnO
₂
) layer on the distal end of a single mode standard optical fiber (SOF) including a fiber Bragg grating. Experimental results are shown, demonstrating the capability of the proposed sensor to perform chemical detection of ammonia in the range of sub-ppm with fast time response and good desorption properties