System and method designing metalens
A system and method designing a metalens including nanostructures and a spacer layer between the nanostructures. The method includes; selecting a design area in relation to a width of the nanostructure and a pitch of the nanostructure, setting a search route in the design area in a direction in which a phase decreases, calculating transmittance at a reference point on the search route and change points near the reference point along the search route, determining the width of the nanostructure and the pitch of the nanostructure, generating a phase map corresponding to the width of the nanostructure and the pitch of the nanostructure, extracting an extracted width of the nanostructure and an extracted pitch of the nanostructure having a target phase from the phase map, and placing the nanostructure having the extracted width and extracted pitch in relation to the metalens corresponding to the target phase.
1 . A metalens design system comprising:
a memory storing a design tool; and
a processor configured to execute the design tool to design a metalens including nanostructures and a spacer layer between the nanostructures,
wherein the design tool is configured to:
select, from an available range of widths of a nanostructure and pitches of the nanostructure, a design range of the widths of the nanostructure and the pitches of the nanostructure;
set a search route in the design range using a phase contour corresponding to the widths of the nanostructure and the pitches of the nanostructure;
generate a phase map indicating a selected portion of the design range;
based on the phase map, determine a target width of the nanostructure and a target pitch of the nanostructure that provide a target phase corresponding to a distance from a center point of the metalens; and
place the nanostructure having the target width and the target pitch at a position of the metalens corresponding to the target phase.
2 . The metalens design system of claim 1 , wherein the design tool is configured to set the search route in the design range in a direction providing a 2π decrease in phase.
3 . The metalens design system of claim 2 , wherein the design tool is configured to:
divide the metalens into a plurality of areas satisfying a phase range condition using the target phase corresponding to the distance from the center point of the metalens; and
generate the phase map for at least one of the plurality of areas,
wherein the phase range condition provides for a 2π phase decrease from a maximum phase value for each of the plurality of areas in relation to the distance from the center point of the metalens.
4 . The metalens design system of claim 3 , wherein the design tool is configured to:
design a first nanostructure design for a first area among the plurality of areas based on the phase map and the target phase corresponding to the distance from the center point of the metalens; and then,
design a second nanostructure design for a second area among the plurality of areas based on the first nanostructure design.
5 . The metalens design system of claim 3 , wherein the plurality of areas includes a first area having a circular shape and including the center point of the metalens, a second area having an annular shape surrounding the first area.
6 . The metalens design system of claim 1 , wherein the design range includes a transmittance reduction range in which transmittance satisfies a set condition, and
wherein the design tool is configured to set the search route such that the search route does not pass through the transmittance reduction range.
7 . The metalens design system of claim 1 , wherein the design tool is configured to:
calculate transmittances of light passing through the metalens along the search route as a function of the widths of the nanostructure and the pitches of the nanostructure; and
generate the phase map based on the transmittances.
8 . The metalens design system of claim 1 , wherein the target phase corresponding to the distance from the center point of the metalens has an offset.
9 . The metalens design system of claim 8 , wherein the design tool is configured to set a plurality of search routes based on the offset.
10 . The metalens design system of claim 1 , wherein the nanostructure has a columnar shape.
11 . The metalens design system of claim 1 , wherein the spacer layer includes a through-hole, and the nanostructure fills the through-hole.
12 . The metalens design system of claim 11 , wherein a shape of the nanostructure is a cylindrical column or a polygonal column.
13 . A method of designing a metalens including nanostructures and a spacer layer between the nanostructures, the method comprising:
selecting a design range of widths of a nanostructure and pitches of the nanostructure;
setting a search route in the design range in a direction in which a phase decreases;
calculating transmittances at a reference point on the search route and at change points near the reference point;
based on the transmittances, generating a phase map indicating a selected portion of the design range;
based on the phase map, determining a target width and a target pitch that provide a target phase; and
placing the nanostructure having the target width and the target pitch.
14 . The method of claim 13 , wherein the setting of the search route in the design range in the direction in which the phase decreases provides for a 2π decrease in phase.
15 . The method of claim 13 , wherein the change points include a first change point changed by a set pitch from the reference point, and a second change point changed by a set width from the reference point.
16 . The method of claim 15 , wherein the change points further include a third point changed by the set pitch and the set width from the reference point.
17 . The method of claim 15 , wherein the change points further include a third point changed by the set pitch from the reference point and having a same phase as the reference point.
18 . A method of designing a metalens including a nanostructure and a spacer layer, the method comprising:
determining a material of the nanostructure, a material of the spacer layer, and a height of the nanostructure;
selecting, from an available range of widths of the nanostructure and pitches of the nanostructure, a design range of the widths of the nanostructure and the pitches of the nanostructure;
setting a search route in the design range in a direction providing a 2π phase decrease from a maximum phase value in the design range using a phase contour corresponding to the widths of the nanostructure and the pitches of the nanostructure;
generating a phase map indicating a selected portion of the design range;
based on the phase map, determining a target width of the nanostructure and a target pitch of the nanostructure that provide a target phase corresponding to a distance from a center point of the metalens; and
placing the nanostructure having the target width and the target pitch at a position of the metalens corresponding to the target phase.
19 . The method of claim 18 , further comprising:
determining the height of the nanostructure after determining the material of the nanostructure and the material of the spacer layer.
20 . The method of claim 18 , wherein the metalens includes a first layer and a second layer disposed on the first layer,
the nanostructure includes a first nanostructure associated with the first layer and a second nanostructure associated with the second layer, and
the spacer layer includes a first spacer layer associated with the first layer and a second spacer layer associated with the second layer.