Optical devices including metastructures and methods for fabricating the optical devices
Methods of manufacturing an optical device can include, in some implementations, providing a substrate having a first polymeric layer on a surface of the substrate and a second polymeric layer on the first polymeric layer, forming first openings in the second polymeric layer to define an etch mask composed of material of the second polymeric layer, and etching to form second openings in the first polymeric layer, wherein locations of the second openings are defined by the etch mask. A material is deposited in the second openings to form meta-atoms of a first metastructure, wherein adjacent ones of the meta-atoms are separated from one another by polymeric material of the first polymeric layer. Optical devices including metastructures can be formed, where meta-atoms of the metastructure have a relatively high aspect ratio.
1 . An optical device comprising:
a substrate comprising a surface;
a first metastructure disposed on the surface of the substrate, wherein the first metastructure includes a first plurality of meta-atoms separated from one another by a first polymeric material, wherein each of the meta-atoms of the first plurality of meta-atoms has an aspect ratio of at least 1.6, wherein a width of the plurality of meta-atoms within the first metastructure varies, and
wherein the first metastructure is configured to function as a lens, a lens array, a beam splitter, a diffuser, or a bandpass filter; and
a second metastructure disposed above the first metastructure,
wherein the second metastructure includes a second plurality of meta-atoms separated from one another by a second polymeric material,
wherein the first polymeric material and the second polymeric material have different coefficients of thermal expansion, different glass transition temperatures, or both different coefficients of thermal expansion and different glass transition temperatures.
2 . The optical device of claim 1 wherein the first polymeric material comprises poly(methyl methacrylate).
3 . The optical device of claim 1 wherein the meta-atoms are composed of titanium dioxide.
4 . The optical device of claim 1 wherein the substrate is composed of fused silica.
5 . A module comprising:
a housing;
an optoelectronic component operable to emit or sense light, wherein the optoelectronic component is disposed within the housing; and
an optical device of claim 1 , wherein the optical device is disposed over the optoelectronic component.
6 . The module of claim 5 wherein the optoelectronic component is a light emitter, and wherein the optical device is disposed so as to intersect a path of light emitted by the light emitter.
7 . The module of claim 5 wherein the optoelectronic component is a light sensor, and wherein the optical device is disposed so as to intersect a path of light entering the module for sensing by the light sensor.
8 . The module of claim 5 including a plurality of optical channels, wherein the optical device spans across one of the optical channels.
9 . The module of claim 5 including a plurality of optical channels, wherein the optical device spans across each of the optical channels.
10 . The optical device of claim 1 , wherein the coefficient of thermal expansion of the first polymeric material is greater than the coefficient of thermal expansion of the second polymeric material.
11 . The optical device of claim 1 , wherein the second metastructure does not overlap the first metastructure in a vertical direction extending orthogonal to the surface of the substrate.