Revealing the underlying mechanisms behind TE extraordinary THz transmission

Suzanna Freer,Miguel Camacho,Miguel Navarro-Cía,Rafael R Boix,Miguel Beruete,Sergei A Kuznetsov

doi:10.1364/prj.8.000430

Abstract

Transmission through seemingly opaque surfaces, so-called extraordinary transmission, provides an exciting platform for strong light–matter interaction, spectroscopy, optical trapping, and color filtering. Much of the effort has been devoted to understanding and exploiting TM extraordinary transmission, while TE anomalous extraordinary transmission has been largely omitted in the literature. This is regrettable from a practical point of view since the stronger dependence of the TE anomalous extraordinary transmission on the array’s substrate provides additional design parameters for exploitation. To provide high-performance and cost-effective applications based on TE anomalous extraordinary transmission, a complete physical insight about the underlying mechanisms of the phenomenon must be first laid down. To this end, resorting to a combined methodology including quasi-optical terahertz (THz) time-domain measurements, full-wave simulations, and method of moments analysis, subwavelength slit arrays under s-polarized illumination are studied here, filling the void in the current literature. We believe this work unequivocally reveals the leaky-wave role of the grounded-dielectric slab mode mediating in TE anomalous extraordinary transmission and provides the necessary framework to design practical high-performance THz components and systems.

Highlights

Diffraction gratings have been ubiquitous in science and technology for more than a century [1], but scientists still find new physics in them
The signature of leaky waves in extraordinary transmission (ET) is revealed when transmission is monitored as a function of the number of periods [8,28,30,31,32,33,34] for TM ET in subwavelength hole arrays and [27,35,36,37] for TM ET inspired highly directive antennas
We believe we have unequivocally revealed the leaky-wave role governing the fully developed TE extraordinary transmission—like TM extraordinary transmission

Summary

Introduction

Diffraction gratings have been ubiquitous in science and technology for more than a century [1], but scientists still find new physics in them. A few theoretical works largely unnoticed by the community [11,12,13] indicated the existence of ET for s-polarized (transverse electric, TE) modes, which was accidentally measured soon thereafter [14] and explicitly reported for different configurations a few years afterward [15,16,17]. These TE modes are classical grounded-dielectric slab modes [18] that can exist in any region of the spectrum, unlike surface plasmon polaritons

Methods

Results

Conclusion