Efficient design of random metasurfaces

Abstract

Random media introduce large degrees of freedom in device design and can thus address challenges in manipulating optical waves. Wave shaping with metasurfaces has mainly utilized periodic or quasi-periodic grids, and, the potential of random arrangement of particles for devices has only come under investigation recently. The main difficulty in pursuing random metasurfaces is the identification of the degrees of freedom that optimize their efficiencies and functions. They can also encode information using the statistics of particles distribution. We propose a phase-map that accounts for the statistical nature of random media.The method takes into account effects of random near-field couplings that introduce phase errors by affecting the phase shift of elements. The proposed approach increases the efficiency of our random metasurface devices by up to ~20%. This work paves the way towards the efficient design of random metasurfaces with potential applications in highly secure optical cryptography and information encoding.

Revisiting the Design Strategies for Metasurfaces: Fundamental Physics, Optimization, and Beyond

“…Later, the random near‐field coupling effect was also considered to resolve the problem by containing statistical information on random metasurfaces. [ 116 ]…”

“…Later, the random near-field coupling effect was also considered to resolve the problem by containing statistical information on random metasurfaces. [116] Alternatively, some theoretical models have been proposed to describe the electromagnetic properties of random metasurfaces. For example, the homogenization of disordered metasurfaces with positional [117] or dimensional [118] randomness has been developed by describing each particle as fluctuating polarizability.…”

Efficient Holographic Focusing Metasurface

“…For example, in contrast to the leaky-wave structures of [20,27], metasurface holograms do not need to be cylindrically symmetric, allowing them to avoid undesired longitudinal components at the focal spot. Meanwhile, metasurface holograms offer the same practical advantages of leaky-wave antennas, i.e., they have low manufacturing costs and a planar form factor, making them a suitable candidate for applications related to beam forming and wavefront shaping [32][33][34][35][36][37].…”

Optical response of jammed rectangular nanostructures

“…In this work, we investigate the optical response of packed rectangular nanostructures on a surface, as they are commonly employed as dipole scatterers in optical devices [7][8][9] for various applications including light harvesting [10] and biosensing [11]. However, a detailed electromagnetic simulation of such an ensemble is a computationally expensive task to perform and one rather seeks the effective medium description as an approximation.…”