Photonic funnels for sub-diffraction propagation and confinement of light

We present phonic funnels, a novel material platform, that enables a smooth optical link between the diffraction-limited and deep subwavelength areas. Photonic funnels comprise conical structures with hyperbolic cores that enable highly confined propagation of light and perfectly conducting walls that isolate the core of the funnel from the surroundings. We demonstrate realization of the funnels with semiconductor metamaterial platform, with minimum diameter of the opening of the order of 1/30-th of free space wavelength and characterize propagation of light through the funnels experimentally and theoretically. We also analyze funnel-induced modulation of emission.