Polarization-dependent resonance tunneling effect with epsilon-near-zero ultra-thin layer

Abstract

We present a theoretical and computational study of resonant optical tunneling (ROT) through an epsilon-near-zero (ENZ) ultra-thin layer, highlighting its potential for designing highly efficient optical devices in the mid-infrared (mid-IR) regime. By leveraging the unique properties of ENZ materials, we demonstrate the realization of a band-pass filter (BPF) with selective transmission characteristics for both transverse electric (TE) and transverse magnetic (TM) polarizations. By optimizing the multilayer design and prism geometry, we demonstrate the realization of a highly efficient BPF with broadband transmission and out-of-band suppression. The ENZ layer enables strong coupling and interference effects, giving rise to asymmetric Fano line shapes in the transmission spectrum. Our analysis reveals that this mechanism achieves high efficiency and polarization sensitivity, making it suitable for mid-IR optical systems requiring compact, high-performance polarizers and filters. Such ENZ-based designs open avenues for advanced applications in sensing, spectroscopy, and infrared photonics.