Terahertz or infrared filter using shape resonance

摘要

A filter having a high transmittance is disclosed. The filter comprises a substrate having a first surface and a second surface, and a periodic or random array of through-holes formed so as to pass through the first surface and the second surface. The through-hole has a size of subwavelength at a range of infrared and terahertz wave. Here, transmission resonance characteristic of incident light on the first surface is controlled by a shape of the through-hole.