Publication

Abstract : Fiber grating based sensors demonstrate great potential especially for the refractive index (RI) based sensing. However, a meticulous effort is still required to improve the sensitivity of optical fiber sensors (OFSs) towards water sensing. In this work, for the first time we have numerically investigated a plus shaped cavity (PSC) within the core of silicon fiber for RI based detection of water samples. The primary objective of incorporating the PSC is to increase the sensitivity while increasing the analytes quantity. The testing of designed cavity sensor model is done within the RI ranging from 1.33 to 1.39 with a remarkable wavelength shift of 65 nm. The autocorrelation coefficient function and sensitivity of proposed PSC sensor for the tested RI range of water samples are 99.69 % and 1083 nm/RIU. The analysis of proposed sensor model is done by using finite difference time domain (FDTD) method. The analysis is done by considering perfect matched layer (PML) as boundary conditions at all the interfaces.