Analysis of sensing characteristics of plasmonic elliptical ring resonator based refractive index sensor

The current research proposes the development of a plasmonic elliptical ring resonator structure with a Metal (Ag) Insulator Metal (Ag) waveguide configuration for the purpose of bio sensing. The research involves a distinctive exploration of the sensitivity and peak resonance wavelength, which are found to be varied by altering the aspect ratio of the elliptical ring resonator. The results reveal a marked increase in sensitivity, ranging from 732.60 nm/RIU to 1113.70nm/RIU, by changing the aspect ratio (ratio of major to minor radius of elliptical ring resonator) from 1.61 to 3.72. Furthermore, these adjustments produce a noticeable redshift in the peak resonance wavelength, as the aspect ratio increases. The study also highlights the impact of other geometrical factors of the sensor on its sensing characteristics. It is found that sensitivity changes significantly with the change in width of resonator and linear waveguide, and it is found to be decreased when width increases. The results of variation in width of waveguides reveals that there occurs a red shift in resonance wavelength when width decrease and vice versa. Based on the finding of all significant geometrical factors an optimized structure is selected with the optimum value of sensitivity. Which evidences its suitability for biosensing purpose and with its superior capabilities, the sensor can play a crucial role in distinguishing between healthy and cancerous cell and will be helpful in detecting cancer at early stage. The investigation and observations involved in the process are computed numerically using the finite difference in time domain method (FDTD).