Bundle Beaming From Multiple Subwavelength Slits Surrounded by Dielectric Surface Gratings

A method for rendering bundle beams by utilizing the destructive interference effects of beams from multiple subwavelength slits surrounded by dielectric surface gratings is proposed. With oblique incident light on the multiple slits, it is possible to control the phases of surface plasmon polaritons (SPPs) induced in the slits. When these phases have a certain relationship, beams from the SPPs excited on the corrugated surface render separated beams or bundle beams, as interfering destructively. Because of the destructive interference, separation between the beams is clear. In addition, the beam width of the bundle beams is narrow, in a degree of several wavelengths of the light.