Properties of High-Tc Single Crystals as Natural Interferometers in the THz Frequency Range

TL;DR

This paper investigates the transmissivity and resonant properties of high-Tc uniaxial superconducting single crystals as natural THz interferometers, revealing their potential for generating ultra-small wavelength light.

Contribution

It introduces a theoretical analysis of THz wave transmission through anisotropic superconductors, highlighting their natural interferometric and resonant capabilities within the Maxwell-London framework.

Findings

Transmissivity is attenuated below plasma frequency for all incident angles.

Superconductors act as natural optical resonators above plasma frequency.

Transmission peaks are modulated by Brewster condition envelope.

Abstract

We consider oblique incidence of (p)TM-polarized wave on the anisotropic superconducting slab, immersed on a dielectric media, such that its uniaxial (c) axis is perpendicular to the surfaces. The below and above plasma frequency transmissivity patterns are studied and several of its properties determined, within the context of the Maxwell-London theory. Below, the regime is attenuated for any incident angle, and there is a transmissivity maximum, quite pronounced in case of a very high external dielectric constant. Above, a propagative regime exists where the superconductor is a natural optical resonator, and we show here that the minimum of the transmission peaks are modulated by an envelope function associated to the Brewster condition. We propose this set-up to obtain light with an extremely small transverse wavelength inside the superconductor.