Tunable Absorption Dynamics in Plasmonic Switch Using Diverse Dielectric Platforms at 1.55 μm Wavelength

Photonic Integrated Circuits (PICs) are central to modern communication and data transmission technologies. It integrates various optical components, among which the optical switch holds a vital and fundamental role. This paper presents the design and theoretical investigation of an electro-absorption optical switch, employing indium–tin–oxide (ITO), graphene and germanium–antimony–selenium–telluride (GSST) as its structural materials. The performance of the switch is influenced by variations in the permittivity of the structural material, which directly governs the absorption dynamics of the device. In addition, the device integrates two different dielectric materials, hafnium dioxide (HfO₂) and silicon nitride (Si₃N₄), for the assessment of its performance metrics. The ITO-based switch with a length of 500 nm demonstrates a maximum extinction ratio (ER) of 29.14 dB/μm and figure-of-merit (FOM) of 626.81. Also, both the ITO-graphene and GSST-graphene based switch showed an insertion loss (IL) of $< $0.19 dB/μm at 500 nm and 2 μm device length. The examined switches hold potential benefits for Next-Gen PICs.