Abstract: A terahertz (THz) anti-reflection device, for example, a broadband tunable THz anti-reflection device, includes a silicon substrate having a plurality of recesses, each of the plurality of recesses having a plurality of cavities of decreasing dimension. The cavities may be nested polygonal cavities, for example, having a square or rectangular cross section. The recesses having the cavities may be positioned at regular periods, for example, periods ranging from 10 ?m to 20 ?m. The devices may be fabricated by conventional lithographic methods. Also disclosed are methods for modifying terahertz radiation and methods for fabricating anti-reflection devices.

Abstract: A broadband anti-reflection apparatus for use with terahertz radiation includes a layer having an outer surface comprising a plurality of pyramid structures having about a 30 ?m to about a 110 ?m period, and wherein reflectance of the terahertz radiation is reduced compared to a layer comprising a planar outer surface. Also disclosed is a method for modifying terahertz radiation which includes receiving terahertz radiation on a device having an anti-reflection layer having an outer surface comprising a plurality of pyramid structures having about a 30 ?m to a 110 ?m period, and modifying the terahertz radiation passing through the device or processing the terahertz radiation in the device.

Abstract: A terahertz (THz) anti-reflection device, for example, a broadband tunable THz anti-reflection device, includes a silicon substrate having a plurality of recesses, each of the plurality of recesses having a plurality of cavities of decreasing dimension. The cavities may be nested polygonal cavities, for example, having a square or rectangular cross section. The recesses having the cavities may be positioned at regular periods, for example, periods ranging from 10 ?m to 20 ?m. The devices may be fabricated by conventional lithographic methods. Also disclosed are methods for modifying terahertz radiation and methods for fabricating anti-reflection devices.

Abstract: A broadband anti-reflection apparatus for use with terahertz radiation includes a layer having an outer surface comprising a plurality of pyramid structures having about a 30 ?m to about a 110 ?m period, and wherein reflectance of the terahertz radiation is reduced compared to a layer comprising a planar outer surface. Also disclosed is a method for modifying terahertz radiation which includes receiving terahertz radiation on a device having an anti-reflection layer having an outer surface comprising a plurality of pyramid structures having about a 30 ?m to a 110 ?m period, and modifying the terahertz radiation passing through the device or processing the terahertz radiation in the device.