Year: 2019
Type: conference-paper
Abstract: Electromagnetic wave is reflected and refracted at interfaces, satisfying Fresnel-Snell law which is required by conservations of energy and momentum. If the incident angle is lower than the critical angle, we can use this Fresnel-Snell law, but the Fresnel-Snell law is modified in the case of existence of dissipation (ñ = n + ik,k > 0) or in the condition of total internal reflection. In the cases, we have to extend the angle of refraction from real number to complex number ( <?CDATA $\theta \to \tilde{\theta }=\theta +i\psi,\psi \ne 0$?> θ → θ ˜ = θ + i ψ , ψ ≠ 0 ). In this paper, by using complex-angle approach, we analyse the behaviour of electromagnetic waves in various kind of interfaces: dielectric - dielectric system, dissipative dielectric - dielectric system, and metal - dielectric system. We show that iso-frequency curves in wavenumber space is opened in the case where n, k > 0, and closed either when n → 0 or when k → 0 (’Lifshitz transition’ of electromagnetic waves). Excess momentum (wavevector) and anomalous circular polarisation emerging with the transition are also discussed.
Author: Daigo Oue
Institution: The University of Osaka
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W2810034018