Enhancing Wavelength Sensing Range of SPR-PCF Using Dual Peak Double Resonance: An LSPR Based Approach

Abstract

A novel sensor developed using GZO and gold as plasmonic materials is proposed in this work. We have designed our sensor in COMSOL Multiphysics software v5.6 and performed its numerical investigation utilizing the FEM. The simulation results manifested the fact that double resonance peaks were created at two specific wavelengths due to the exclusive dispersion relation arising by the concurrent use of two plasmonic materials. A unique parameter termed as DPSS has been presented by taking shifting of the double resonance peaks into consideration and the optimization of the presented design has been accomplished with a view to achieving the maximum value of DPSS. At optimal design conditions, a highest DPSS value of 11,720 um/ RIU was acquired, and the sensor depicted the potentiality of analyte detection constituting a wide RI range of 1.30 to 1.40. Furthermore, the working range of the sensor was found to be in the broad wavelength spectrum of 0.3 um to 0.98 um which ascertains its efficacy in both the ultra-violet and visible spectral range. An acutely low value of Confinement Loss (CL) has also been illustrated by the sensor making it appropriate for larger sensor lengths[1]. Moreover, the sensor we proposed demonstrated a maximal Wavelength Sensitivity (WS) of 11,480 nm/RIU while detecting analytes constituting the range of RI of 1.39-1.40 with a precise sensor resolution value of 8.71× 10–6 RIU correspondingly. Therefore, expediency of the sensor in both the ultra-violet and visible spectrum range confirms its novelty and credibility in a diverse range of biosensing applications while its high DPSS and WS values, minute wavelength resolution value and low CL values uphold its position as an efficacious medium of analyte detection in the field of biosensing.