Abstract

Employing functional and structured thin films on fiber optic sensors has tremendously improved capabilities in humidity sensing applications. In this paper, we demonstrate fabrication of a fiber optic evanescent wave humidity sensor based on S i O 2/porous polymethyl methacrylate (PMMA) thin films. With the exposure to moisture, S i O 2/porous PMMA thin films absorb water molecules. The refractive index and absorption coefficient of thin films change with ambient humidity, resulting in modulation of the light intensity transmitted in fiber. A good linearity is determined between the logarithm of output light intensity and relative humidity (RH). An optimal average sensitivity of 188.3 lux/%RH is achieved with an increase of 11.7 fold in the RH range of 5% to 95%. The response and recovery times are 8s and 23s, respectively. Furthermore, the sensor exhibits low hysteresis, and excellent stability and repeatability.

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

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.