Metal Oxide-Graphene-Based Quasi-D-Shaped Optical Fiber Plasmonic Biosensor

Abstract

A quasi-D-Shaped photonic crystal fiber plasmonic biosensor operating in near infrared is proposed for refractive index sensing. Chemically stable graphene and indium tin oxide layers are used outside the fiber structure to realize a simple detection mechanism. The design of quasi-D-shaped fiber makes the sensor configuration more simple and easy to use. And the proposed sensor shows the wavelength interrogation sensitivity of 3908–10693 $\text{nm/RIU}$ in the dynamic index range from 1.33 to 1.38. It also shows the maximum amplitude sensitivity of 95 $\text{RIU}^{-1}$ at the wavelength of 2040 nm with the analyte refractive index (RI) of 1.37. Compared with traditional D-shaped optical fiber, the proposed quasi-D-Shaped fiber has the advantages of easier to make and the promising results makes it a potential candidate for detecting biomolecules, water quality analysis and other analytes.