Optical Fiber Refractometers with Tunable Sensitivity Based on Indium Tin Oxide Coatings

摘要

In this work, the electromagnetic resonance phenomenon originated on indium tin oxide (ITO) coated optical fibers is studied as a function of the ITO coating thickness. These novel devices overcome the major drawbacks of the traditional prism based Kretschmann configuration, such as the utilization of polarized light or the necessity of a big and expensive coupling prism due to the optical fiber setup. In addition, the utilization of ITO coated optical fibers as the resonance supporting coating permits the tenability of the resonance wavelength and the sensitivity of the devices by adjusting the ITO coating thickness. More specifically, the sensitivity of these devices has been raised from 2121 nm/Refractive index unit (RIU) of a device of 220 nm ITO coating thickness to 3658 nm/RIU and 3698 nm/RIU for devices of ITO coating thicknesses of 115 nm and 85 nm respectively.