Tunneling of electromagnetic waves: paradoxes and prospects
A.B. Shvartsburg a, b
a Joint Institute for High Temperatures, Russian Academy of Sciences, ul. Izhorskaya 13/19, Moscow, 127412, Russian Federation
b Space Research Institute, Russian Academy of Sciences, Profsoyuznaya str. 84/32, Moscow, 117997, Russian Federation
Electromagnetic wave tunneling through a photonic barrier and the phenomenon of frustrated total internal reflection (FTIR) are considered for different spectral wavelength ranges. It is found that in a dielectric gradient barrier nonlocal dispersion occurs, whose cutoff frequency is formed by, and dependent on the shape and geometry of, the dielectric constant profile ε(z), and which is shown to be key to wave tunneling through gradient media. Particular attention is given to total transmittance below the cutoff frequency in the FTIR (reflectionless tunneling) regime typical of gradient media. Exact analytical solutions of Maxwell’s equations for tunneling effects
in heterogeneous transparent dielectrics are used to demonstrate that these phenomena are common for a wide range of wavelengths. Theoretical controversies over FTIR are reviewed and perspectives on the use of gradient photonic barriers in thin layer filters and
polarizers, high efficiency reflectors, and reflection free coatings are discussed.