Metasurfaces with asymetric gratings for redirecting light and methods for fabricating

• Main Authors: LIN, DIAN-MIN, MELLI, MAURO, HILAIRE, PIERRE ST, PEROZ, CHRISTOPHE, POLIAKOV, EVGENI YURIY
• Format: Patent
• Language: Chinese; English
• Published: 01.12.2017
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICS; PHYSICS; PICTORIAL COMMUNICATION, e.g. TELEVISION

An optical system comprises an optically transmissive substrate comprising a metasurface which comprises a grating comprising a plurality of unit cells. Each unit cell comprises a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width. A pitch of the unit cells is 10 nm to 1 [mu]m. The heights of the first and the second nanobeams are: 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and 10 nm to 1 [mu]m where the refractive index is 3.3 or less.