Camera with phased metalens
A camera includes a phased metalens positioned between an objective lens and an imager of the camera. The phased metalens is configured to adjust a focus plane of an image in a field of view of the camera in response to changes in an operating temperature of the camera. The phased metalens adjusts the focus plane for multiple frequencies or wavelengths light such that all light wave-fronts exiting the phased metalens arrive at the imager at a same time.
1. A camera, comprising:
a phased metalens positioned between an objective lens and an imager of the camera;
the phased metalens configured to adjust a focus plane of an image in a field of view of the camera in response to changes in an operating temperature of the camera,
wherein the phased metalens comprises a plurality of sub-wavelength structures being grouped into arrangements having unique phase profiles based on the operating temperature of the camera.
2. The camera of claim 1 , wherein the phased metalens is positioned within 1 mm of an imager focal plane.
3. The camera of claim 1 , wherein the phased metalens adjusts the focus plane for multiple frequencies or wavelengths of light.
4. The camera of claim 3 , wherein the wavelengths range from 400 nm to 1600 nm.
5. The camera of claim 1 , wherein the phased metalens adjusts the focus plane over a temperature range of about 145 degrees Celsius.
6. The camera of claim 5 , wherein the phased metalens adjusts the focus plane over changes in a focal length of about 16 μm.
7. The camera of claim 1 , wherein the plurality of sub-wavelength structures are positioned at predetermined coordinates across the phased metalens.
8. The camera of claim 7 , wherein the plurality of sub-wavelength structures range from two times to eight times smaller than a wavelength of light transmitted through the phased metalens.
9. The camera of claim 7 , wherein the plurality of sub-wavelength structures are grouped into a plurality of arrangements having unique phase profiles;
the unique phase profiles configured to adjust a phase of light transmitted through the plurality of arrangements.
10. The camera of claim 9 , wherein the unique phase profiles are based on the arrangement's respective radial distance from a center of the phased metalens.
11. The camera of claim 9 , wherein the plurality of arrangements define a plurality resolution units.
12. The camera of claim 11 , wherein the plurality of resolution units located at a same radius from a center of the phased metalens have identical phase profiles.
13. The camera of claim 11 , wherein the plurality of resolution units located at a different radius from a center of the phased metalens have different phase profiles.
14. The camera of claim 11 , wherein a size of one resolution unit is equal a size of four image pixels.
15. The camera of claim 14 , wherein each image pixel includes about 30 to 36 sub-wavelength structures.
16. The camera of claim 14 , wherein each resolution unit includes about 120 to 144 sub-wavelength structures.
17. The camera of claim 11 , wherein as the respective radial distance of the plurality of resolution units increases from a center of the phased metalens, the unique phase profiles increase an amount of phase adjustment for a given wavelength of light.
18. The camera of claim 11 , wherein as a radial distance of the plurality of resolution units increases from a center of the phased metalens, the unique phase profiles increase an amount of phase adjustment for decreasing wavelengths of light.
19. The camera of claim 11 , wherein as a radial distance of the plurality of resolution units increases from a center of the phased metalens, the unique phase profiles increase an amount of phase adjustment for a given temperature.
20. The camera of claim 11 , wherein as a radial distance of the plurality of resolution units increases from a center of the phased metalens, the unique phase profiles increase an amount of phase adjustment for increasing temperatures.
21. The camera of claim 1 , wherein all light wave-fronts exiting the phased metalens arrive at the imager at a same time.
22. A system, comprising:
an apparatus for use in a camera, the apparatus comprising:
a phased metalens positioned between an objective lens and an imager of the camera;
the phased metalens configured to adjust a focus plane of an image in a field of view of the camera in response to changes in an operating temperature of the camera,
wherein the phased metalens comprises a plurality of sub-wavelength structures being grouped into arrangements having unique phase profiles based on the operating temperature of the camera.