Large-Angle, Multifunctional Metagratings Based on Freeform Multimode Geometries

• DOI: 10.1021/acs.nanolett.7b01082
• Publication Date: 2017-05-01T19:46:50Z
• Authors: David Sell; Jianji Yang; Sage Doshay; Rui Yang; Jonathan A. Fan
• Keywords: Image stitching; Nanophotonics; Waveguide

We show that silicon-based metagratings capable of large-angle, multifunctional performance can be realized using inverse freeform design. These devices consist nonintuitive nanoscale patterns and support a large number spatially overlapping optical modes per unit area. The quantity modes, in combination with their optimized responses, provides the degrees freedom required to produce high-efficiency devices. To demonstrate power versatility our approach, we fabricate efficiently deflect light 75° angles steer beams different diffraction orders based on wavelength. A theoretical analysis Bloch supported by these elucidates spatial mode profiles coupling dynamics make high-performance beam deflection possible. This approach represents new paradigm nano-optical engineering utilizes physics from current state-of-the-art, which is stitching noninteracting waveguide structures. envision design will enable classes photonic systems strategies toward control fields.