Milled Microchannel-Assisted Open D-Channel Photonic Crystal Fiber Plasmonic Biosensor

M Hussayeen Khan Anik,Sakib Mahmud,M Ifaz Ahmad Isti,S M Riazul Islam,Hriteshwar Talukder,Md Jalil Piran,Shovasis Kumar Biswas,Kyung-Sup Kwak

doi:10.1109/access.2020.3047509

Abstract

A surface plasmon resonance (SPR) based photonic crystal fiber (PCF) sensor having a milled microchannel, and an open D-channel has been proposed in this paper. The sensor shows good functionality in the wide sensing range of 1.14-1.36 Refractive Index Units (RIU) of the analyte, having the capability to detect low refractive index (RI). The Finite Element Method (FEM) based numerical investigations dictate that the proposed sensor has been able to gain a maximum wavelength sensitivity of 53,800 nm/RIU according to the wavelength interrogation technique. The amplitude interrogations show that the sensor has the highest amplitude sensitivity of 328 RIU−1. The highest FOM (Figure of Merit) has been found to be 105 RIU−1. The sensor evinces a minimum wavelength resolution of $1.86\times 10 ^{-6}$ RIU, which secures high detection accuracy. A circular perfectly matched layer (PML) is implemented in the sensor’s outermost layer as a boundary condition to absorb surface radiations. Gold is the plasmonic metal, while TiO2 acts as the adhesive layer for gold attachment on silica. Due to the high sensitivity with a broad range of analyte detection, the sensor is well suited for practical biochemical detection purposes.

Highlights

A photon coupling to an exciton gives rise to a polariton at the right frequency
The plasmonic oscillations occurring on a metal surface produce surface plasmonic waves (SPW)
The probable cause for the red shifting of the resonant wavelength, λ is that higher refractive index (RI) of analyte on the periphery causes the damping of the plasmonic waves

Summary

INTRODUCTION

A photon coupling to an exciton gives rise to a polariton at the right frequency. The plasmonic oscillations occurring on a metal surface produce surface plasmonic waves (SPW). With the advancement of the fabrication technology, different D-shaped open channel PCF-SPR sensors have been designed, which show higher sensitivity with a broad analyte sensing range. In the broad analyte sensing range 1.18-1.36 RI, capable of detecting low RI of analytes Their sensitivities are moderate in comparison to the most recent advancements in PCF SPR sensor designs. Though the D-shape designs have introduced more volume of the analyte to interact with the core, the photonic crystal orientation did not support the lattice design to reach moderately high sensitivity values. The highest wavelength sensitivity has been ascertained to be 53,800 nm/RIU, with the highest SA = 328 RIU−1 This is the highest spectral sensitivity that has been achieved in this broad analyte sensing range to the best of our knowledge, capable of detecting very low refractive indices of analytes

THEORETICAL CONSIDERATIONS

AMPLITUDE INTERROGATION METHOD

ANECDOTE FOR FUTURE IMPROVEMENTS

CONCLUSION