Plus Shaped Single Grating based Optical Fiber Structure for Water Sensing Application

Abstract Fiber grating sensors demonstrate great potential especially for the refractive index based sensing. However, a meticulous effort is still required to improve the sensitivity of fiber grating sensors towards water sensing. In this work, for the first time we have numerically investigated a plus shaped single grating within the core of optical fiber for water sensing applicaions. The primary objective of incoroporating the plus shaped grating within the core is to increase the sensitivity in comparison to existing grating sensors while increasing the analytes quantity. The testing of designed grating sensor model is done within the refractive index range from 1.33 to 1.39 with a remarkable wavelength shift of 65 nm. The analysis of proposed model of grating sensor is accomplished by using finite difference time domain (FDTD) method under the contour of perfect matched layer (PML) as boundary conditions at the interface of core and grating. The attained results depicts the significant sensitivity of the proposed fiber grating sensor for water sample sensing.