Comparison of Basic Frequency Selective Surface Design Methods for Optical Windows

Methods for designing frequency selective surface for optical windows are analyzed and experimentally verified. Four methods; ITO coatings, graphene, metallic nano-coatings and metallic meshes; are compared in terms of optical transmission and shielding effectiveness (SE) characteristics. ITO is the most common method for increasing SE performance in the visible band. However, in the infrared band, transmission of ITO is limited. Metallic nano-coating is an alternative for ITO with underperformance from the SE and optical transmission point. Graphene is an emerging method and needs further development. SE performance of the graphene prevents it from being a single material for shielding applications. On the other hand, it might be involved in applications where back reflection is critical because of the electromagnetic absorption characteristic. Metallic mesh is a successful candidate for applications requiring high level SE and optical transmission. However, dielectric properties of substrate the mesh applied, and diffraction effects should be carefully analyzed.