Analog Optical Computing Based on Dielectric Meta-reflect-array

TL;DR

This paper demonstrates an innovative dielectric meta-reflect-array that enables analog optical computing by manipulating electromagnetic waves with full phase and amplitude control, offering a compact, efficient alternative to traditional bulky systems.

Contribution

It introduces a CMOS-compatible dielectric metasurface design capable of performing broadband mathematical operations like differentiation and integration in the telecommunication range.

Findings

Achieved full phase coverage of 2π and amplitude control from 0 to 1.

Realized broadband differentiator and integrator functions.

Overcame limitations of plasmonic metasurfaces in the visible range.

Abstract

In this paper, we realize the concept of analog computing using an array of engineered gradient dielectric meta-reflect-array. The proposed configuration consists of individual subwavelength silicon nanobricks in combination with fused silica spacer and silver ground plane realizing a reflection beam with full phase coverage $2\pi$ degrees as well as amplitude range $0$ to $1$. Spectrally overlapping electric and magnetic dipole resonances, such high-index dielectric metasurfaces can locally and independently manipulate the amplitude and phase of the incident electromagnetic wave. This practically feasible structure overcomes substantial limitations imposed by plasmonic metasurfaces such as absorption losses and low polarization conversion efficiency in the visible range. Using such CMOS-compatible and easily integrable platforms promises highly efficient ultrathin planar wave-based computing systems which circumvent the drawbacks of conventional bulky lens-based signal processors. Based on these key properties and general concept of spatial Fourier transformation, we design and realize broadband mathematical operators such as differentiator and integrator in the telecommunication wavelengths.