A sub-wavelength holes diffraction radiation array

The letter explores the physics of the diffraction radiation of a subwavelength holes array. We show when a line current is uniformly moving above the array, a novel diffraction radiation array is discovered, in which each hole emits its own radiation in both sides of the array as a radiation cell, and all these cells together organize a distinct diffraction radiation array. Therefore, under the excitation of a line current, the subwavelength holes array becomes a radiation array. Making use of the integral equation method, analytical theory for such a novel diffraction radiation is built up. The results of the calculations of this theory agree with that by the computer simulation. The discovery and the theory of the novel diffraction radiation array are of great significance of the subwavelength holes array physics and optics.