On light addressing within subwavelength metallic gratings

We consider a zero-order diffraction metallic grating having two subwavelength rectangular slits per period. The electromagnetic behavior of this system is studied theoretically in the resonance spectral domain of the cavities. We show that, by choosing judicious opto-geometrical parameters, we can perform the selective excitation of one or the other category of cavities with a very appreciable quality factor, illustrating then a switch effect. The results open the way to the quantitative light addressing on passive metallic micro/nano-structures. In particular, for transmitting gratings, we can force light to cross each subwavelength channel doublet through a determined aperture, reconsidering in some extent the Young's slits experiment.