Tunneling inhibition for subwavelength light

摘要

We show that light tunneling inhibition may take place in suitabledynamically modulated waveguide arrays for light spots whose features areremarkably smaller than the wavelength of light. We found that tunnelingbetween neighboring waveguides can be suppressed for specific frequencies ofthe out-of-phase refractive index modulation, affording undistorted propagationof the input subwavelength light spots over hundreds of Rayleigh lengths.Tunneling inhibition turns out to be effective only when the waveguideseparation in the array is above a critical threshold. Inclusion of a weakfocusing nonlinearity is shown to improve localization. We analyze thephenomenon in purely dielectric structures and also in arrays containingperiodically spaced metallic layers.