Study of chitosan layer-based Fabry Perot Interferometer optical fiber sensor properties for detection of Pb2+, Hg2+ and Ni2+

Abstract

This work presents investigation of properties of optical fiber sensor based on Fabry-Perot interferometer using chitosan to detect Pb2+, Hg2+ and Ni2+. The sensor was fabricated by employing chitosan layer on the tip of single mode optical fiber (SMF) which serves as Fabry-Perot interferometer. Some of the light transmitted in the SMF were reflected back due to multiple reflection in the interferometer. The chitosan was coated on the fiber end by using dip coating technique. Three sensors were fabricated which are sensor A, B and C with coating thickness of 141.85 μm, 105.52 μm and 129.25 μm, respectively. Characterization was done for sensitivity and response time of the sensors. The results showed that sensor B which was characterized for Hg2+ provided the highest sensitivity and the most stable response time.