Terahertz Sensing with Extraordinary Optical Transmission Hole Arrays

Purpose: The purpose of this paper is to substantiate the enhanced performance of hyperbolic anisotropic (HA) meta-surfaces at anomalous extraordinary optical transmission (EOT) resonances. These resonances exhibit distinct transmission peaks highly sensitive to environmental changes, making them particularly valuable for sensing applications. By demonstrating improved transmission efficiency and sensitivity, this study aims to contribute to developing advanced sensing technologies that leverage the unique properties of HA meta-surfaces in detecting minute variations in their surroundings. Methodology: To verify the enhanced sensing performance of anomalous EOT resonances, this study employs a well-established experimental method involving depositing a thin analyte layer of varying thicknesses onto the meta-surface. The study aims to determine which resonance condition provides optimal sensitivity by comparing the performance between regular and anomalous EOT resonances. It explores the improved performance of HA meta-surfaces at anomalous EOT resonances, which occur under certain non-standard conditions, offering potentially superior sensing capabilities compared to regular EOT. Findings: The results indicate that when the analyte is applied to the non-patterned side of the metasurface, the anomalous EOT resonance achieves superior sensing performance. This enhanced sensitivity can be attributed to the unique interaction dynamics between the incident THz waves and the meta-surface structure under abnormal conditions. Unique Contribution to Theory, Policy and Practice: This phenomenon is beneficial in the terahertz (THz) range, making HA meta-surfaces ideal for thin-film label-free sensing applications. The EOT resonance occurs due to the interaction between incident light and the periodic structure of the holes, leading to enhanced light transmission at specific wavelengths. The findings highlight the potential of using anomalous EOT resonances in HA meta-surfaces to develop highly sensitive and efficient sensors for detecting changes in thin films, paving the way for advanced sensing technologies in various scientific and industrial applications.