Electrically-tunable optical filter

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.