Double-layered optical color filter structure

Abstract

The invention discloses a double-layered optical color filter structure. The double-layered optical color filter structure comprises a metal silver layer with periodic round holes forming a round hole array, and a circular ring array positioned right above the metal silver layer and made of metal silver, wherein the circular ring array exactly faces the round hole array. According to the double-layered optical color filter structure consisting of the round hole array and the circular ring array and based on metal silver, the metal silver circular ring array is added above the single metal silver layer with the round hole array, meanwhile, the lower metal silver layer is thinned and the round holes are enlarged, so that the lower surface of the double-layered structure can excite stronger surface plasmon, the anti-reflection light intensity is stronger, the rejection ratio of transmission signals is improved, and the transmission curves have more smooth line types and stronger symmetry. Besides, the structure provided by the invention can select the required transmission wavelength through adjusting the cycles of both the round hole array and the circular ring array.

Description

technical field [0001] The invention belongs to the technical field of optical filtering, in particular to a double-layer optical color filtering structure composed of a circular hole array and a circular ring array based on metallic silver material. Background technique [0002] The research on the anti-reflection structure of the metal perforated array has been emerging in the past ten years. As early as in 1998, the research team of T.W.Thomos discovered a periodic circular hole array with a square lattice on the metal silver film. The structure has a series of different wavelengths. the transmission peak. The intensity of these transmission peaks is much higher than previously predicted theoretically, and their transmission intensity normalized to the area occupied by the holes can exceed 100%. Moreover, the positions of these transmission peaks are directly determined by the array of circular holes. The wavelengths other than these transmission peaks have very small t...

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Problems solved by technology

[0003] From a practical point of view, the single-layer metal perforated array optical filter structure also has certain defects. These defects mainly include: 1. The wavelength that can be transmitted is not a single one, and there are multiple wavelengths that can be transmitted. The line shape is not very regular; 2. The symmetry is poor. Although there is strong transmission, the transmittance that can be achieved is only a dozen to 20 percent at most; 3. Anti-reflection and non-anti-reflection The light suppression ratio is not high

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