Development and analysis of surface plasmon resonance based refractive index sensor for pregnancy testing

In the proposed work, a two-dimensional photonic crystal fiber (PCF) based on the surface plasmon resonance (SPR) refractive index sensor has been demonstrated and designed which is so much helpful to gain a better sensitivity response in urine observation. In order to detect the pregnancy, the simulation and analysis have been performed in both normal and pregnant urine with the effective refractive indices values of 1.335, 1.34, 1.342 and 1.343 within the range of working wavelength from 1.75 µm to 2 µm. From this testing sensor, the optical parameters of the dispersion relation, birefringence, coupling length, confinement loss, insertion loss, sensor length, crosstalk, sensitivity response, resonance wavelength, resolution, and sensitivity per line-width have been analyzed. Besides, Finite element method (FEM) is used for the numerical investigations. From this investigation, the highest value of sensitivity response, sensitivity per line-width, and the resolution of 68051.344 nm/RIU, 314 RIU⁻¹, and 9.39 × 10⁻⁶ RIU are gained. It is noted that the proposed sensor offers significant sensing performances for the polarized modes. The main goal of this investigation is to develop the concepts of optoelectronics and laser bio-sensor in the field of biological detection systems. As a result, this structure of optical biosensor will be applicable through the modified optical fiber in biological changes.