Performance evaluation of D-shaped photonic crystal fiber based SPR sensors with different plasmonic materials: A comparative analysis

• A simple and unique plasmonic sensor using d-shaped PCF is proposed. • Different plasmonic materials such as gold, silver, titanium, platinum, and palladium are used as plasmonic material to analyze sensor's efficacy. • Gold, silver, titanium, platinum, and palladium is obtained as 20,000 nm/RIU, 25,000 nm/ RIU, 15,000 nm/RIU, 5000 nm/RIU, and 15,000 nm/RIU, respectively, over the refractive index (RI) range of 1.31 to 1.35. • Among these silver-based and gold-based sensors demonstrate superior detection responses and enhanced sensor performance. • The selection of plasmonic material plays a substantial role in sensor performance, with each material possessing its unique characteristics and applications. Photonic crystal fiber (PCF)-based surface plasmon resonance (SPR) sensors excel in enhancing sensing efficiency, influenced by diverse geometric parameters like air hole diameter, plasmonic materials, and their thickness. Choosing the appropriate plasmonic material is crucial for maximizing sensing efficiency in PCF-based SPR sensors. Hence, this study aims to investigate the influence of various plasmonic materials on sensor performance, with the goal of enhancing sensing efficiency through structural optimization. For minimizing fabrication complexity, a simple and unique plasmonic sensor design is proposed, utilizing d-shaped PCF. In this design, gold, silver, titanium, platinum, and palladium are used as plasmonic materials, inducing the SPR effect while simultaneously enhancing sensor performance. The finite element method (FEM) is used to conduct numerical analyses to assess optical parameters, such as confinement loss, wavelength sensitivity, figure of merit (FOM), and resolution for these materials. Following the optimization of various geometric parameters, the maximal wavelength sensitivity for gold, silver, titanium, platinum, and palladium is obtained as 20,000 nm/RIU, 25,000 nm/ RIU, 15,000 nm/RIU, 5000 nm/RIU, and 15,000 nm/RIU, respectively, over the refractive index (RI) range of 1.31 to 1.35. With its superior wavelength sensitivity, the proposed sensors utilizing these plasmonic materials can be employed across various sensing applications.