A novel plasmonic sensor using solid core D-shaped negative curvature optical fiber with AU–TiO₂ layer

Abstract

Recently, unique structure fiber enacts a significant role in sensing applications. A novel D-shaped negative curvature fiber based surface plasmon resonance (SPR) sensor is proposed. The design consists of negative curvature solid core fiber surrounded by a cladding composed of double-layer adjoined airholes. An outside layer of the cladding contains semi-circular airholes, and the interior layer has small circular air holes to overwhelm the higher-order modes. The external sensing approach detects changes in the refractive index between 1.33 and 1.37. Employing gold as a plasmonic material, SPR is developed on top of the photonic crystal fiber (PCF). Between the gold layer and the PCF, a small layer of titanium dioxide is placed for binding the plasmonic material to the fiber. And it acts as an adhesive layer. The finite element method is used to perform numerical analyses. After improving the structural parameters, an enhanced sensitivity of 26 000 nm RIU−1 is achieved. Because of its enhanced sensitivity, this sensor is used in a bio-medical application to detect and prevent diseases in the early stage.

Performance Enhancement of Gold Coated D-shaped PCF Sensor Using Monolayer MoS2

“…Gold is selected as a plasmonic material as it exhibits high resonance wavelength shift, less sensitive to humidity and temperature and also it is a chemically stable element [28]. The relative permittivity of gold is acquired from Drude-Lorentz model [29].…”

“…To enhance the detection capability and sensitivity of SPR based PCF sensors, various novel materials and hybrid structures have been explored in recent years [14,15]. For example, various plasmonic metal coatings like gold (Au), silver (Ag), indium tin oxide (ITO), etc have been integrated with 2D materials for enhanced sensing of the samples [16,17].…”