Electrically-tunable optical filter

Patent metadata

Field	Value
Publication number	US-12072601-B2
Application number	US-202318127889-A
Country	US
Kind code	B2
Filing date	Mar 29, 2023
Priority date	May 25, 2021
Publication date	Aug 27, 2024
Grant date	Aug 27, 2024

Abstract

An optical device stack includes at least one of a photodetector or an optical emitter and a metasurface. The metasurface is disposed over a light-receiving surface of the photodetector or a light emission surface of the optical emitter. The metasurface includes a first conductive layer having an electrically-tunable optical property and an array of conductive nanostructures disposed on a first side of the first conductive layer. A second conductive layer is disposed on a second side of the first conductive layer. An electrical insulator is disposed between the first conductive layer and the second conductive layer. A change in an electrical bias between the metasurface and the second conductive layer, from a first electrical bias to a second electrical bias, tunes the electrically-tunable optical property from a first state to a second state, and changes an electrically-tunable optical filtering property of the metasurface.

First claim

What is claimed is:

1. An optoelectronic device, comprising:
a pixel having a light-emitting surface and including,
a metasurface disposed over the light-emitting surface and including an array of conductive nanostructures disposed on a first conductive layer;
a second conductive layer disposed over the light-emitting surface; and
an insulating layer disposed over the light-emitting surface, between the metasurface and the second conductive layer;

a voltage source electrically connected to the metasurface and the second conductive layer; and
a controller configured to change a voltage between the metasurface and the second conductive layer.

2. The optoelectronic device of claim 1 , further comprising:
an array of pixels including the pixel, wherein multiple pixels in the array of pixels each include,
a respective metasurface including a respective array of conductive nanostructures disposed on a respective first conductive layer;
a respective second conductive layer; and
a respective insulating layer disposed between the respective metasurface and the respective second conductive layer; and

a respective voltage source electrically connected to the respective metasurface and the respective second conductive layer of each pixel in the multiple pixels.

3. The optoelectronic device of claim 2 , wherein:
the pixel is a first pixel;
the multiple pixels include a second pixel; and
the controller is configured to program respective voltage sources that are electrically connected to the first pixel and the second pixel, to apply a same voltage to the first pixel and to the second pixel at a same time.

4. The optoelectronic device of claim 2 , wherein:
the pixel is a first pixel;
the multiple pixels include a second pixel;
the controller is configured to program respective voltage sources that are electrically connected to the first pixel and the second pixel, to apply a first voltage to the first pixel and a second voltage to the second pixel at a same time; and
the first voltage is different from the second voltage.

5. The optoelectronic device of claim 2 , wherein each pixel of the multiple pixels comprises a respective photodetector positioned to receive electromagnetic radiation through a respective metasurface.

6. The optoelectronic device of claim 2 , wherein each pixel of the multiple pixels comprises a respective optical emitter positioned to emit electromagnetic radiation through a respective metasurface.

7. A method of measuring light, comprising:
receiving a first set of wavelengths of light through a metasurface while the metasurface is in a first state, the metasurface comprising an array of nanostructures and a layer of material having an electrically-tunable optical property;
measuring a first intensity of the first set of wavelengths;
applying a voltage to the metasurface to bias the metasurface to a second state different from the first state;
receiving a second set of wavelengths of light through the metasurface while the metasurface is in the second state; and
measuring a second intensity of the second set of wavelengths.

8. The method of claim 7 , wherein:
the light including the first set of wavelengths and the second set of wavelengths is ambient light; and
the method further comprises characterizing the ambient light using at least the first intensity and the second intensity.

9. The method of claim 7 , wherein the layer of material having the electrically tunable optical property comprises indium tin oxide.

10. The method of claim 7 , further comprising:
applying at least one additional voltage to the metasurface to bias the metasurface to at least one respective additional state.

11. The method of claim 7 , further comprising:
adjusting a setting of a display responsive to the characterization of the ambient light.

12. An optical device stack, comprising:
at least one of a photodetector or an optical emitter;
a metasurface disposed over at least one of a light-receiving surface of the photodetector or a light emission surface of the optical emitter and including,
a first conductive layer having an electrically-tunable optical property; and
an array of conductive nanostructures disposed on a first side of the first conductive layer;

a second conductive layer disposed on a second side of the first conductive layer, over at least one of the light-receiving surface of the photodetector or the light emission surface of the optical emitter; and
an electrical insulator disposed between the first conductive layer and the second conductive layer.

13. The optical device stack of claim 12 , wherein a change in an electrical bias between the metasurface and the second conductive layer, from a first electrical bias to a second electrical bias, tunes the electrically-tunable optical property from a first state to a second state and changes an electrically-tunable optical filtering property of the metasurface.

14. The optical device stack of claim 12 , wherein the first conductive layer comprises indium tin oxide.

15. The optical device stack of claim 12 , wherein the array of conductive nanostructures comprises an array of nanowires.

16. The optical device stack of claim 12 , wherein the second conductive layer comprises gold.

17. The optical device stack of claim 12 , further comprising:
a silicon nitride layer; wherein,
the second conductive layer is disposed on the silicon nitride layer and is between the silicon nitride layer and the electrical insulator.

18. The optical device stack of claim 12 , wherein:
the first electrical bias is zero volts (V); and
when the electrically-tunable optical property is tuned to the first state, the metasurface has an optical passband peak at a visible electromagnetic radiation wavelength.

19. The optical device stack of claim 18 , wherein the visible electromagnetic radiation wavelength is one of a red electromagnetic radiation wavelength, a green electromagnetic radiation wavelength, or a blue electromagnetic radiation wavelength.

20. The optical device stack of claim 18 , wherein:
when the electrically-tunable optical property is tuned to the second state, the metasurface has an optical passband peak at one of,
a different visible electromagnetic radiation wavelength than when the electrically-tunable optical property is tuned to the first state; or
a near-infrared electromagnetic radiation wavelength.

Assignees

• Apple Inc

Inventors

• Li Jiayu
• Lu Dawei

Classifications

• H10W90/00

  Package configurations · CPC title

• H10H20/855

  Optical field-shaping means, e.g. lenses · CPC title

• H10F77/413

  directly associated or integrated with the devices, e.g. back reflectors (directly associated or integrated with photovoltaic cells H10F77/42) · CPC title

• H10F77/70

  Surface textures, e.g. pyramid structures · CPC title

• H10F77/331

  for filtering or shielding light, e.g. multicolour filters for photodetectors · CPC title