Meta-surface filter for visible frequency range based on meta-materials

Abstract

To enhance the efficiency of exposure in greenhouses during specific cultivation periods, it is essential to design a meta-face that effectively filters the green part of visible light. This targeted filtering function will enable optimal control of the light spectrum, resulting in better cultivation conditions and increased productivity. Leveraging innovative concepts and advanced methods, a highly efficient meta-surface design aimed at filtering the green portion of the visible light spectrum is proposed. The proposed structure comprises periodic arrays of graphene disks and rings strategically positioned on both sides of a silicon oxide substrate. This straightforward coated layer configuration offers a practical solution for greenhouses and controlled agriculture applications, facilitating improved light management and tailored growth conditions. Through two separate simulation paths, the validity and accuracy of our proposed approach were investigated. Both theoretical analysis and simulation results demonstrate that the proposed structure attenuates the green part of visible light. Filtered output waves prove to be highly beneficial for indoor cultivation, during the flowering period, offering improved control over light conditions. The design methodology relies on an equivalent circuit model and impedance matching criteria. Additionally, full-wave simulation is performed to verify the effectiveness of the employed modeling. According to the simulation results, the proposed meta-surface effectively filters the green part of visible light, while allowing the transmission of the red spectrum.