Impact of angular displacement between dual plasmonic layers in LSPR-PCF sensing

This paper presents a pioneering method to enhance sensitivity in plasmonic photonic crystal fiber (PCF) sensors by integrating localized surface plasmon resonance (LSPR) with dual plasmonic materials, gold and Aluminium Zinc Oxide (AZO). The uniqueness of the proposed work lies in the analysis of the angular displacement between the dual plasmonic materials at four discrete angles (0, 60, 120, and 180) while maintaining other structural parameters constant. The air hole combinations are also strategically arranged to ensure proper light guidance to the plasmonic layers. An enhancement of 1.8x has been achieved for the maximal WS by altering the angular displacement. A modified method of evaluating AS has been proposed through which the attainable value is -9970.36 RIU-1, while eliminating off-resonant dips in the spectra. This value surpasses those reported in recent works, which focused on limited angle configurations. Apart from the promising improvements in sensing parameters, riveting information regarding the electric field pattern of the plasmonic modes and the trend in the confinement loss are obtained which are critical for machine learning integration in photonics. The novelty of this work lies in achieving preferable optical parameters using a specific combination of plasmonic materials and air holes without altering their original dimensions, a feat not previously demonstrated. This study opens new avenues for advancing sensitivity in plasmonic PCF sensors, offering promising prospects for diverse sensing applications.