Tunable localization of light using nested invisible metasurface cavities.

An invisible cavity is an open resonant device that confines a localized field without producing any scattering outside of the device volume. By exploiting the scatter-less property of such device, it is possible to nest two invisible cavities, as the outer cavity would simply not notice the presence of the inner one, regardless of their relative position. As a result, the position of the inner cavity becomes a means to easily control the field localized inside the cavity and its quality factor.

Unusual eigenmodes of wire-medium endoscopes: impact on transmission properties.

Wire-medium endoscopes represent a promising tool of THz sensing/imaging. Bending should not critically harm the endoscope operation and the issue of bending losses is that of key importance for any endoscope. In this paper we show that the frequency-averaged power transmittance of a wire-medium endoscope is weakly sensitive to the bending.