Abstract
A relative humidity (RH) fiber optic sensor is demonstrated based on the multimode interference (MMI) phenomenon utilizing a no-core fiber (NCF) coated with polyvinyl alcohol (PVA). The sensor’s structure is simple and consists of a section of NCF spliced between two standard single-mode fibers (SMFs). The fabrication and testing of a tapered version with enhanced sensitivity is also presented. The native MMI sensor showed a sensitivity of 5.6nm/RH%, in the range from 87 RH% to 93 RH%, while the tapered one exhibited an increased sensitivity of 6.6nm/RH%, in the range from 91.5 RH% to 94 RH%. The sensitivity values obtained with these MMI sensors are at least twice as large as the most sensitive fiber optics humidity sensor reported in the literature in a similar RH range.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
