Diffraction gratings formed by metasurfaces having differently oriented nanobeams

US10466394B2 · kind B2 · utility

Assignee

• Magic Leap, Inc. · US

Inventors

• Dianmin Lin · Los Altos, US
• Michael Anthony Klug · Austin, US
• Pierre St. Hilaire · Belmont, US
• Mauro Melli · San Leandro, US
• Christophe Peroz · San Francisco, US
• Evgeni Poliakov · San Mateo, US

Key dates

• Filing date: Jan 25, 2018
• Grant date: Nov 5, 2019
• Expiry date: Apr 28, 2038

Classification

• Technology area (CPC G): Physics
• CPC primary: G03H2223/16
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 μm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization.