Meta-optical device having variable performance and electronic device including the same

Patent metadata

Field	Value
Publication number	US-12066740-B2
Application number	US-202117552139-A
Country	US
Kind code	B2
Filing date	Dec 15, 2021
Priority date	Dec 16, 2020
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

A meta-optical device, which imparts a phase delay to incident light of a wavelength band, includes: a first electrode and a second electrode spaced apart from each other; a liquid crystal layer between the first electrode and the second electrode; a meta-surface layer located within the liquid crystal layer and including a plurality of nanostructures each having a shape dimension smaller than a center wavelength of the wavelength band; and a voltage device configured to apply a voltage between the first electrode and the second electrode. The meta-optical device may exhibit an electrically controlled variable focal length.

First claim

What is claimed is:

1. A meta-optical device which imparts a phase delay to incident light of a wavelength band, the meta-optical device comprising:
a first electrode and a second electrode spaced apart from each other;
a liquid crystal layer between the first electrode and the second electrode;
a meta-surface layer located within the liquid crystal layer, the meta-surface layer comprising a plurality of nanostructures each having a shape dimension smaller than a center wavelength of the wavelength band; and
a voltage device configured to apply a voltage between the first electrode and the second electrode,
wherein the meta-surface layer comprises a plurality of unit cells, and
wherein each of the plurality of unit cells comprises a pair of a first nanostructure of the plurality of nanostructures and a second nanostructure of the plurality of nanostructures, wherein the first nanostructure has different dimensions from the second nanostructure.

2. The meta-optical device of claim 1 ,
wherein an angle between a major axis of liquid crystal molecules in the liquid crystal layer and a first direction parallel to the meta-surface layer increases according to the voltage applied between the first electrode and the second electrode.

3. The meta-optical device of claim 2 ,
wherein the meta-optical device exhibits a first focal length when the angle is 0°, and exhibits a second focal length shorter than the first focal length, when the angle is 90°.

4. The meta-optical device of claim 3 ,
wherein the meta-optical device exhibits a third focal length shorter than the first focal length and longer than the second focal length, when the angle is between 0° and 90°.

5. The meta-optical device of claim 2 ,
wherein a focal length of the meta-optical device is gradually reduced as the angle increases from 0° up to 90°.

6. The meta-optical device of claim 2 ,
wherein a phase φ of the meta-optical device for each of angles 0°, θ 1 , θ 2 , θ 3 , and 90° between the major axis of the liquid crystal molecules and the first direction, satisfies the following condition:
φ(90°)<φ(θ 3 )<φ(θ 2 )<φ(θ 1 )<φ(0°)

(here, 0°<θ 1 <θ 2 <θ 3 <90°).

7. The meta-optical device of claim 6 ,
wherein the meta-optical device satisfies the following condition:
Φ<1.5 radian

(here, Φ is defined as follows:)

Φ
=

∑

i
=
1

4

⁢



ΔΦ
i

-

mean
⁡

(

ΔΦ
i

)



4

ΔΦ
1

=

ϕ
⁡

(

90
⁢
°

)

-

ϕ
⁡

(

67
⁢
°

)

,

ΔΦ
2

=

ϕ
⁡

(

67
⁢
°

)

-

ϕ
⁡

(

45
⁢
°

)

ΔΦ
3

=

ϕ
⁡

(

45
⁢
°

)

-

ϕ
⁡

(

22
⁢
°

)

,

ΔΦ
4

=

ϕ
⁡

(

22
⁢
°

)

-

ϕ
⁡

(

0
⁢
°

)

.

8. The meta-optical device of claim 2 ,
wherein each of the plurality of nanostructures comprises a quadrangular prism in which at least one side is parallel to the first direction.

9. The meta-optical device of claim 1 ,
wherein when viewed from a cross-section parallel to the meta-surface layer, the first nanostructure and the second nanostructure each have a rectangular shape having a width parallel to the first direction and a length parallel to a second direction perpendicular to the first direction.

10. The meta-optical device of claim 2 ,
wherein a focal length is f1 when the angle is 0°, and
wherein the focal length is f1/2 when the angle is 90°.

11. The meta-optical device of claim 2 ,
wherein a focal length is f1 when the angle is 0°, and
wherein the focal length is −f1 when the angle is 90

Assignees

• Samsung Electronics Co Ltd
• Univ Cornell

Inventors

• Won Kanghee
• Shcherbakov Maxim Radikovich
• Lee Hongseok
• Bosch Melissa
• Shvets Gennady

Classifications

• H04N23/67

  Focus control based on electronic image sensor signals · CPC title

• G02F2203/50

  Phase-only modulation · CPC title

• G02F2202/36

  Micro- or nanomaterials · CPC title

• G02F2202/30

  Metamaterials · CPC title

• G02B5/1876

  Diffractive Fresnel lenses; Zone plates; Kinoforms (G02B5/1842, G02B5/1847 take precedence; optical systems having diffractive correction means G02B27/0037; Fresnel lenses operating by refraction G02B3/08) · CPC title