Single chip spectral polarization imaging sensor

Patent metadata

Field	Value
Publication number	US-12130180-B2
Application number	US-202217887716-A
Country	US
Kind code	B2
Filing date	Aug 15, 2022
Priority date	Aug 13, 2021
Publication date	Oct 29, 2024
Grant date	Oct 29, 2024

Abstract

An image sensor capable of recording both spectral and polarization properties of light using a single chip device includes an at least 2048 by 2048 array of superpixels. Each superpixel includes an array of spectral pixels, and an adjacent array of polarization pixels. Each spectral pixel includes a spectral filter and a stack of photodiodes, where each photodiode has a different quantum efficiency and is, therefore, sensitive to a different wavelength of light passed by the spectral filter. Each polarization pixel includes a polarization filter and a stack of photodiodes, similar to the spectral pixel photodiode stacks.

First claim

What is claimed is:

1. A superpixel for a digital camera, the superpixel comprising:
an array of spectral pixels and an adjacent array of polarization pixels, wherein:
each spectral pixel comprises:
a first stack of at least two photodiodes, each photodiode of the at least two photodiodes configured to have a quantum efficiency at a wavelength different from the quantum efficiency at the wavelength of each other photodiode of the at least two photodiodes; and
a spectral filter configured to pass at least two transmission peaks to its respective first stack of at least two photodiodes; and

each polarization pixel comprises:
a second stack of at least two photodiodes, each photodiode of the at least two photodiodes configured to have a quantum efficiency at a wavelength different from the quantum efficiency at the wavelength of each other photodiode of the at least two photodiodes; and
a polarization filter configured to pass a polarization of light to its respective second stack of at least two photodiodes different from the polarization passed by each other polarization filter in the superpixel.

2. A superpixel according to claim 1 , wherein the superpixel comprises three spectral pixels.

3. A superpixel according to claim 2 , wherein:
the spectral filter of a first one of the three spectral pixels is an optical comb filter configured to pass transmission peaks in the ranges of 400-425 nm, 475-500 nm, and 550-575 nm;
the spectral filter of a second one of the three spectral pixels is an optical comb filter configured to pass transmission peaks in the ranges of 425-450 nm, 500-525 nm, and 575-600 nm; and
the spectral filter of a third one of the three spectral pixels is an optical comb filter configured to pass transmission peaks in the ranges of 450-475 nm, 525-550 nm, and 600-625 nm.

4. A superpixel according to claim 1 , wherein the superpixel comprises three polarization pixels.

5. A superpixel according to claim 4 , wherein:
the polarization filter of a first one of the three polarization pixels is configured to pass a 0 degree polarization of light;
the polarization filter of a second one of the three polarization pixels is configured to pass a 60 degree polarization of light; and
the polarization filter of a third one of the three polarization pixels is configured to pass a 120 degree polarization of light.

6. A superpixel according to claim 1 , wherein each spectral pixel comprises a first stack of three photodiodes.

7. A superpixel according to claim 1 , wherein each polarization pixel comprises a second stack of three photodiodes.

8. A superpixel according to claim 1 , wherein each photodiode in a first stack of photodiodes has a different quantum efficiency.

9. A superpixel according to claim 1 , wherein each photodiode in a second stack of photodiodes has a different quantum efficiency.

10. A superpixel according to claim 1 , wherein each photodiode is a CMOS photodetector.

11. A pixelated image sensor comprising:
an at least 2048 by 2048 array of superpixels, wherein each superpixel comprises:
an array of spectral pixels and an adjacent array of polarization pixels, wherein:
each spectral pixel comprises:
a first stack of at least two photodiodes, each photodiode of the at least two photodiodes configured to have a quantum efficiency at a wavelength different from the quantum efficiency at the wavelength of each other photodiode of the at least two photodiodes; and
a spectral filter configured to pass at least two transmission peaks to its respective first stack of at least two photodiodes; and

each polarization pixel comprises:
a second stack of at least two photodiodes, each photodiode of the at least two photodiodes configured to have a quantum efficiency at a wavelength different from the quantum efficiency at the wavelength of each other photodiode of the at least two photodiodes; and
a polarization filter configured to pass a polarization of light to its respective second stack of at least two photodiodes different from the polarization passed by each other polarization filter in the superpixel.

12. A pixelated image sensor according to claim 11 , wherein each superpixel comprises three spectral pixels.

13. A pixelated image sensor according to claim 11 , wherein for each superpixel:
the spectral filter of a first one of the three spectral pixels is an optical comb filter configured to transmit photons having wavelengths in the ranges of 400-425 nm, 475-500 nm, and 550-575 nm;
the spectral filter of a second one of the three spectral pixels is an optical comb filter configured to transmit photons having wavelengths in the ranges of 425-450 nm, 500-525 nm, and 575-600 nm; and
the spectral filter of a third one of the three spectral pixels is an optical comb filter configured to transmit photons having wavelengths in the ranges of 450-475 nm, 525-550 nm, and 600-625 nm.

14. A pixelated image sensor according to claim 11 , wherein each superpixel comprises three polarization pixels.

15. A pixelated image sensor according to claim 14 , wherein for each superpixel:
the polarization filter of a first one of the three polarization pixels is configured to pass a 0 degree polarization of light;
the polarization filter of a second one of the three polarization pixels is configured to pass a 60 degree polarization of light; and
the polarization filter of a third one of the three polarization pixels is configured to pass a 120 degree polarization of light.

16. A pixelated image sensor according to claim 11 , wherein, in each superpixel, each spectral pixel comprises a first stack of three photodiodes.

17. A pixelated image sensor according to claim 11 , wherein, in each superpixel, each polarization pixel comprises a second stack of three photodiodes.

18. A pixelated image sensor according to claim 11 , wherein, in each superpixel, each photodiode in a first stack of photodiodes has a different quantum efficiency.

19. A pixelated image sensor according to claim 11 , wherein, in each superpixel, each photodiode in a second stack of photodiodes has a different quantum efficiency.

20. A pixelated image sensor according to claim 11 , wherein the array of superpixels has a superpixel pitch no greater than 10 μm.

Assignees

• Univ Illinois

Inventors

• Gruev Viktor

Classifications

• H10F77/413

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

• H10F39/1825

  Multicolour image sensors having stacked structure, e.g. NPN, NPNPN or multiple quantum well [MQW] structures · CPC title

• H10F30/288

  the devices being sensitive to multiple wavelengths, e.g. multi-spectrum radiation detection devices · CPC title

• G01J4/04 Primary

  Polarimeters using electric detection means (G01J4/02 takes precedence) · CPC title

• G01J2003/2806

  Array and filter array · CPC title