A layered metastructure for privacy protection based on the Brewster angle.

In this paper, a kind of layered metastructure (LMS) is proposed by stacking multi-layer dielectric plates. By adjusting the dielectric constant of medium A (set as ), the Brewster angle (BA) of incident electromagnetic waves (EMWs) has been directly selected. At the same time, the operating band of the above angle selection (AS) can be extended to the whole visible light band (VLB) which covers 400 nm to 700 nm according to Bragg reflection. After careful design, two ranges of BAs that cross 0° to 42° and 0° to 60° have been realized in the VLB, which is defined as privacy protection (PP) in this paper. Compared with previous reports, this accomplishment improves transmissivity at small angles and covers a large band. Also, the gradient thickness of the proposed LMS can be changed arbitrarily according to the needs of operating bands, which undoubtedly expands the actual operating scenarios. The obtained results can offer some help to the design of directional devices in industry production, the PP of daily life, and so on.