We show that light tunneling inhibition may take place in suitable dynamically modulated waveguide arrays for light spots whose features are remarkably smaller than the wavelength of light. We found that tunneling between neighboring waveguides can be suppressed for specific frequencies of the out-of-phase refractive index modulation, affording undistorted propagation of the input subwavelength light spots over hundreds of Rayleigh lengths. Tunneling inhibition turns out to be effective only when the waveguide separation in the array is above a critical threshold. Inclusion of a weak focusing nonlinearity is shown to improve localization. We analyze the phenomenon in purely dielectric structures and also in arrays containing periodically spaced metallic layers.
© 2013 Optical Society of America
Diffraction and Gratings
Original Manuscript: June 12, 2013
Manuscript Accepted: July 4, 2013
Published: July 29, 2013
Changming Huang, Xianling Shi, Fangwei Ye, Yaroslav V. Kartashov, Xianfeng Chen, and Lluis Torner, "Tunneling inhibition for subwavelength light," Opt. Lett. 38, 2846-2849 (2013)