A Novel Plus Shaped Cavity Based Optical Fiber Sensor for the Detection of Escherichia-Coli

Abstract

In this work, we have demonstrated the refractive index (RI) based sensing of Escherichia Coli (E -Coli) by introducing a novel plus shaped cavity in optical fiber. This plus-shaped cavity increases the interaction between the signal and the analytes, that improves the sensitivity. The proposed sensor model is achieved by combining the lateral and vertical slots in optical fiber core structure. The sensing ability of the plus shaped cavity has been examined in visible range, where the RI of E -Coli ranges from 1.38 to 1.395. The numerical investigation of sensor structure has been done by employing the finite difference time domain (FDTD) method. The geometrical analysis of plus shaped cavity indicates that; the maximum output power is achieved at the slot width of 600 nm. The proposed cavity is capable of sensing the presence of E -Coli with the autocorrelation function and sensitivity of 99.54 % and 2125 nm/RIU, respectively.