Effect Of Liquid Cladding on the Transmission Characteristics of a UShaped Glass Optical Fiber Refractive Index Sensor Operating at Various Temperatures

Abstract

The light transmission from one end to the other end of the optical fiber occurs as long as the
diameters of the core and cladding are same throughout the length of the fiber. Any change
i.e., either internal perturbation or external perturbation in the fiber structure at any region of
the fiber results in the loss of light transmitting through fiber in the form of higher-order
leaky modes or radiation modes in the form of evanescent waves, which region can be
exploited as a sensing zone to measure various environmental parameters. In the present
work, a U-shaped glass rod is connected between two PCS fibers of 200/230μm diameters
which becomes the clad removed part of the light transmission system and hence acts as the
sensing zone of the sensor to sense the refractive index of liquids either transparent or dark at
various temperatures between 10oC and 60oC.