A method for dielectric characterization at extreme high temperature based on multi-mode spoof localized surface plasmons

Abstract Extreme-high-temperature dielectric characterization is challenging and costly. In this work, the spoof localized surface plasmons (SLSPs) are introduced for the detection of high-temperature dielectric constant of ceramic materials. Confinement of electromagnetic fields and strong correlation between multiple modes of SLSPs are investigated to reduce random errors in characterizing lossy materials. This method is validated through testing on Rogers materials and further applied in harsh environments to measure the permittivity of alumina at the temperature up to 1250 °C after correction of thermal strain. This proposed method is accurate, convenient and low-cost, possessing great potentials for in aerospace and other fields.