PSHE-enhanced temperature sensor based on nonlinear magneto-optics and plasmonics

Abstract

A highly sensitive optical temperature sensor based on photonic spin Hall effect (PSHE)-induced beam shifts in a magneto-plasmonic multilayer configuration is theoretically proposed. The structure consists of an Au–TiO2–graphene anisotropic thin-film stack operating in the Kretschmann geometry with a GaP prism and with ethanol as the temperature-dependent sensing medium. Under surface plasmon resonance excitation in the mid-infrared wavelength regime, the spin-dependent in-plane and out-of-plane spatial beam shifts exhibit strong dependence on temperature. The sensor response is further analyzed through external magnetic field modulation and electrostatic gating of graphene, enabling controlled manipulation of magneto-optic and carrier-induced effects. Owing to the enhancement, the proposed scheme achieves a remarkably high temperature sensitivity of 3.49cm/K. The presented study highlights the potential of magneto-plasmonically assisted PSHE-based platforms for tunable and high-resolution temperature sensing, with prospective applications in nanophotonics, integrated optical sensing, and multifunctional plasmonic devices. © 2026 World Scientific Publishing Company.