Hyperbolic metamaterial interfaces: Hawking radiation from Rindler horizons and the "end of time"

Extraordinary rays in a hyperbolic metamaterial behave as particle world lines in a three dimensional (2+1) Minkowski spacetime. We analyze electromagnetic field behavior at the boundaries of this effective spacetime depending on the boundary orientation. If the boundary is perpendicular to the space-like direction in the metamaterial, an effective Rindler horizon may be observed which produces Hawking radiation. On the other hand, if the boundary is perpendicular to the time-like direction an unusual physics situation is created, which can be called "the end of time". It appears that in the lossless approximation electromagnetic field diverges at the interface in both situations. Experimental observations of the "end of time" using plasmonic metamaterials confirm this conclusion.Comment: 21 pages, 4 figure

Modelling and directionally encoding the acoustics of a room

Geometrical methods are often used to model the acoustic properties of a room, but are valid only for high frequencies. At low frequencies. diffraction and the effects of room modes cannot be neglected. A method for modelling the two-dimensional propagation of sound within an enclosed room is presented which encompasses both of these particular properties by making use of a digital waveguide model

Comparison of imaging with sub-wavelength resolution in the canalization and resonant tunnelling regimes

We compare the properties of subwavelength imaging in the visible wavelength range for metal-dielectric multilayers operating in the canalization and the resonant tunnelling regimes. The analysis is based on the transfer matrix method and time domain simulations. We show that Point Spread Functions for the first two resonances in the canalization regime are approximately Gaussian in shape. Material losses suppress transmission for higher resonances, regularise the PSF but do not compromise the resolution. In the resonant tunnelling regime, the MTF may dramatically vary in their phase dependence. Resulting PSF may have a sub-wavelength thickness as well as may be broad with multiple maxima and a rapid phase modulation. We show that the width of PSF may be reduced by further propagation in free space, and we provide arguments to explain this surprising observation.Comment: 17 pages,12 figure