Metasurface phase change communicator

Patent metadata

Field	Value
Publication number	US-11522128-B2
Application number	US-201916290077-A
Country	US
Kind code	B2
Filing date	Mar 1, 2019
Priority date	Mar 2, 2018
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A metasurface unit cell for use in constructing a metasurface array is provided. The unit cell may include a ground plane layer comprising a first conductive material, and a phase change material layer operably coupled to the ground plane layer. The phase change material layer may include a phase change material configured to transition between an amorphous phase and a crystalline phase in response to a stimulus. The unit cell may further include a patterned element disposed adjacent to the phase change material layer and includes a second conductive material. In response to the phase change material transitioning from a first phase to a second phase, the metasurface unit cell may resonate to generate an electromagnetic signal having a defined wavelength. The first phase may be the amorphous phase or the crystalline phase and the second phase may be the other of the amorphous phase or the crystalline phase.

First claim

What is claimed is:

1. A metasurface unit cell comprising:
a ground plane layer comprising a first conductive material;
a phase change material layer operably coupled to the ground plane layer, the phase change material layer comprising a phase change material configured to transition between an amorphous phase and a crystalline phase in response to a stimulus;
a patterned element disposed adjacent to the phase change material layer, the patterned element comprising a second conductive material; and
wherein, with the phase change material in a second phase, the metasurface unit cell is configured to operate as a resonator that generates an electromagnetic signal comprising a defined wavelength, wherein the defined wavelength is an infrared wavelength;
wherein the first phase is the amorphous phase or the crystalline phase and the second phase is the other of the amorphous phase or the crystalline phase; and
wherein with the phase change material is in the first phase, the metasurface unit cell is configured to not resonate to generate the electromagnetic signal comprising the defined wavelength.

2. The metasurface unit cell of claim 1 , wherein the defined wavelength is based on a layout of the patterned element.

3. The metasurface unit cell of claim 1 , wherein the stimulus comprises an optical signal, an electrical signal, or a thermal signal applied to the phase change material.

4. The metasurface unit cell of claim 1 , wherein the phase change material comprises a chalcogenide glass.

5. The metasurface unit cell of claim 1 , wherein the defined wavelength is in the range of about 800 nanometer to 15 micrometers.

6. The metasurface unit cell of claim 1 , wherein a thickness of the metasurface unit cell is less than one micrometer.

7. The metasurface unit cell of claim 1 , wherein a thickness of the phase change material layer is at least 200 times less than the defined wavelength of the electromagnetic signal.

8. The metasurface unit cell of claim 1 , wherein the stimulus is provided by an element of a vertical cavity surface emitting laser (VCSEL).

9. A metasurface array comprising:
a ground plane layer comprising a first conductive material;
a phase change material layer operably coupled to the ground plane layer, the phase change material layer comprising a phase change material configured to transition between an amorphous phase and a crystalline phase in response to a stimulus;
a plurality of first patterned elements disposed adjacent to the phase change material layer, the first patterned elements having a first layout; and
a plurality of second patterned elements disposed adjacent to the phase change material layer, the second patterned elements having a second layout;
wherein, with the phase change material adjacent the first patterned elements in a second phase, a first assembly comprising the first patterned elements, the phase change material layer, and the ground plane layer is configured to operate as a first resonator that generates a first electromagnetic signal comprising a first defined wavelength, the first defined wavelength being in the infrared spectrum;
wherein, with the phase change material adjacent the second patterned elements in a fourth phase, a second assembly comprising the second patterned elements, the phase change material layer, and the ground plane layer is configured to operate as a second resonator that generates a second electromagnetic signal comprising a second defined wavelength, the second defined wavelength being in the infrared spectrum and the second defined wavelength being different from the first defined wavelength;
wherein the first phase is the amorphous phase or the crystalline phase and the second phase is the other of the amorphous phase or the crystalline phase to the first phase; and
wherein the third phase is the amorphous phase or the crystalline phase and the fourth phase is the other of the amorphous phase or the crystalline phase to the third phase.

10. The metasurface array of claim 9 wherein the plurality of first patterned elements are grouped in a first region forming a first pixel and the plurality of second patterned elements are grouped in a second region forming a second pixel.

11. The metasurface array of claim 9 , wherein the first defined wavelength is based on a first layout of the first patterned elements and the second defined wavelength is based on a second layout of the first patterned elements.

12. The metasurface array of claim 9 , wherein the stimulus comprises an optical signal, an electrical signal, or a thermal signal applied to the phase change material at selected locations of the metasurface array associated with the plurality of first patterned elements or the plurality of second patterned elements.

13. The metasurface array of claim 9 , wherein the phase change material comprises a chalcogenide glass.

14. The metasurface array of claim 9 , wherein the first defined wavelength and the second defined wavelength are in the range of about 800 nanometers to 15 micrometers.

15. The metasurface array of claim 9 , wherein a thickness of the metasurface array is less than one micrometer.

16. The metasurface array of claim 9 , wherein a thickness of the phase change material layer is at least 200 times less than the first defined wavelength of the first electromagnetic signal or the second defined wavelength of the second electromagnetic signal.

17. The metasurface array of claim 9 , wherein the stimulus is provided by a vertical cavity surface emitting laser (VCSEL) array having an optical output for each first patterned element and each second patterned element.

18. A method comprising:
applying a stimulus to a phase change material of a metasurface unit cell;
transitioning the phase change material from a first phase to a second phase in response to the application of the stimulus of the phase change material, the first phase being an amorphous phase or a crystalline phase and the second phase being the other of the amorphous phase or the crystalline phase; and
with the phase change material in the second phase to configure the metasurface unit cell to operate as a resonator at a defined wavelength, generating an electromagnetic signal at the defined wavelength, the defined wavelength being an infrared wavelength,
wherein the metasurface unit cell comprises the patterned element, the phase change material, and a ground plane layer, wherein the patterned element is disposed adjacent to the phase change material, and the phase change material is operably coupled to the ground plane layer.

19. The method of claim 18 further comprising:
removing the stimulus from the phase change material;
transitioning the phase change material from the second phase to the first phase in response to the removal of the stimulus from the phase change material; and
ceasing generation of the electromagnetic signal at the defined wavelength due to transitioning the phase change material to the first phase.

20. The method of claim 19 , wherein applying the stimulus comprises applying an optical signal, an electrical signal, or a thermal signal to the phase change material.

Assignees

• Univ Johns Hopkins

Inventors

• Shrekenhamer David B
• Maranchi Jeffrey P
• Miragliotta Joseph A
• Caruso Keith S

Classifications

• H10W40/00

  Arrangements for thermal protection or thermal control (integrated devices comprising arrangements for thermal protection H10D89/60) · CPC title

• G02F1/0054

  Structure, phase transitions, NMR, ESR, Moessbauer spectra · CPC title

• G02F2202/30

  Metamaterials · CPC title

• H01Q15/0086 Primary

  said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials · CPC title

• G02F2203/15

  involving resonance effects, e.g. resonantly enhanced interaction · CPC title