Optical transmission control apparatus utilizing metal films perforated with subwavelength-diameter holes

摘要

An optical transmission modulation apparatus (20) is provided for modulating light transmitted through the apparatus. The apparatus comprises a metal film having a periodic array of subwavelength-diameter holes (12) provided therein, and a supporting layer (14). At least a portion of the supporting layer has a selectively variable refractive index, the selectively variable refractive index portion being substantially adjacent to the metal film such that the metal film and the supporting layer form a perforated metal film unit. Selective variation of the refractive index of the selectively variable refractive index portion modulates the intensity of the light transmitted through the perforated metal film unit without substantially changing the direction of the light. Flat panel displays, spatial light modulators and tunable optical filters based on the optical transmission control apparatus are also provided.