2022/08/10 by Mohamed Ismail Abdelrahman, Francesco Monticone, Abdelrahman, Mohamed Ismail +1
Engineering · Materials Science · Physics and Astronomy · #Advanced Antenna and Metasurface Technologies #FOS: Physical sciences #Metamaterials and Metasurfaces Applications #Optics (physics.optics) #Photonic Crystals and Applications
paper · pdf · doi:10.48550/arxiv.2208.05533
openalex publication_date 2022/08/10 · openalex created_date 2022/08/13 · openalex updated_date 2026/07/28
Light reflection plays a crucial role in a number of modern technologies. In this paper, analytical expressions for maximal reflected power in any direction and for any polarization are given for generic planar structures made of a single material represented by a complex scalar susceptibility. The problem of optimal light-matter interactions to maximize reflections is formulated as the solution of an optimization problem in terms of the induced currents, subject to energy conservation and passivity, which admits a global upper bound by using Lagrangian duality. The derived upper bounds apply to a broad range of planar structures, including metasurfaces, gratings, homogenized films, photonic crystal slabs, and more generally, any inhomogeneous planar structure irrespective of its geometrical details. These bounds also set the limit on the minimum possible thickness, for a given lossy material, to achieve a desired reflectance. Moreover, our results allow discovering parameter regions where large improvements in the efficiency of a reflective structure are possible compared to existing designs. Examples are given of the implications of these findings for the design of superior and compact reflective components made of real, imperfect (i.e., lossy) materials, such as ultra-thin and efficient gratings, polarization converters, and light-weight mirrors for solar/laser sails.