Donuts make diffractionless electromagnetic waves

► A diffractionless beam can be obtained using periodically arranged donut (torus) waveguides. ► The Bessel like field distribution is observed at the output of the waveguide. ► The diameter of the diffractionless beam is of the order of magnitude of the wavelength. ► The structure may be built for electromagnetic waves of any wavelength, including radiowaves, microwaves, infrared light, visible light and UV light.