All-Dielectric Metasurface-Based Beam Splitter with Arbitrary Splitting Ratio

Abstract

The development of optical systems is heading to multi-branch circuit design and miniaturization. A beam splitter is a common device for dividing an incident beam into two separate beams. Conventional beam splitters are constructed using coated prisms or glass plate. Their bulky size, right-angled output direction, and fixed splitting ratio greatly limit the design of optical arrangement and also hinder the system integration. Here, an all-dielectric metasurface composed of symmetric nano-rings as a beam splitter are designed by Finite-Difference Time-Domain method. By changing the inner and outer radiuses of the nano-rings, the wavefront phase of the emergence beam can be adjusted to form a phase gradient, and the incident beam of arbitrary polarization is divided into two beams according to the designed transmittance and angle. The initial phase of the emergence beam can be changed by adjusting the refractive index of the substrate or adding the silicon film to the substrate, and the splitting ratio can be adjusted from 0.5:1 to 1:1. The simulation demonstrates that the metasurface-based beam splitter is independent of polarization and the power efficiency is over 92% with a compact area of 33.6 μm × 33.6 μm. This compact metasurface-based beam splitter has promising potential for enabling new types of compact optical systems and advancing metasurface-based functional integrated photonic applications.

Quasi-Freeform Metasurfaces for Wide-Angle Beam Deflecting and Splitting

“…Hence, a design strategy that can realize high deflecting performance with less-consuming time is needed. As for the metasurface-based beam splitters, recent works were mainly conducted by utilizing forward design method to improve the splitting performance of gradient metasurfaces [ 15 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. Among these beam splitters, a splitting efficiency of 93.4% was achieved, while the splitting angle was only 50° [ 34 ].…”

A Beam-Split Metasurface Antenna for 5G Applications

“…The metasurface is widely used in antenna design to enhance the gain, bandwidth, polarization, and steering of the antenna beams [19]- [23]. It has the capability to steer beams or produce multiple beams antennas with high gain and polarization characteristics [24], [25].…”

Single-Step Fabrication of Longtail Glasswing Butterfly-Inspired Omnidirectional Antireflective Structures

“…The light reflection from optical systems, such as a camera lens, corrective lenses, panel displays, automotive dashboards, and face shields incurs veil glare and degrades overall optical performance. To diminish the unfavorable light reflection, single-layer/multilayer interference coatings consisting of transparent materials with appropriate refractive indices have been widely used to moderate the refractive index change [ 3 , 4 , 5 , 6 ]. However, low-refractive-index transparent materials are scarce and highly priced.…”