Photon number resolving superconducting detector

Patent metadata

Field	Value
Publication number	US-11313719-B2
Application number	US-201916623503-A
Country	US
Kind code	B2
Filing date	Apr 30, 2019
Priority date	May 1, 2018
Publication date	Apr 26, 2022
Grant date	Apr 26, 2022

Abstract

A photon detector is provided. The photon detector includes a superconducting wire having a plurality of alternating narrow and wide portions; a current source electrically-coupled to the superconducting wire and configured to supply the superconducting wire with electrical current; and an optical waveguide optically coupled to the plurality of narrow portions of the superconducting wire.

First claim

What is claimed is:

1. A photon detector, comprising:
a superconducting wire having a plurality of alternating narrow and wide portions;
a current source electrically-coupled to the superconducting wire and configured to supply the superconducting wire with electrical current;
an optical waveguide optically coupled to the plurality of narrow portions of the superconducting wire; and
an electrical contact electrically-coupled in parallel with the superconducting wire,
wherein the electrical contact has a resistance that is less than a resistance of the superconducting wire while at least one narrow portion of the superconducting wire is in a non-superconducting state.

2. The photon detector of claim 1 , wherein each narrow portion of the plurality of narrow portions is straight to reduce current crowding effects within the narrow portion.

3. The photon detector of claim 1 , wherein at least one wide portion of the plurality of wide portions is bent.

4. The photon detector of claim 1 , wherein the narrow portions each have a first width and the wide portions each have a second width, the second width being greater than the first width.

5. The photon detector of claim 1 , further comprising a readout circuit electrically-coupled to the superconducting wire and configured to measure an electrical property of the superconducting wire, wherein the electrical property is indicative of a number of photons incident to the superconducting wire.

6. The photon detector of claim 5 , wherein the electrical property comprises a voltage across the superconducting wire or an impedance of the superconducting wire.

7. The photon detector of claim 6 , wherein the readout circuit is configured to measure the voltage across the electrical contact electrically-coupled in parallel with the superconducting wire.

8. The photon detector of claim 1 , wherein the optical waveguide is tapered to improve coupling, such that a downstream portion of the optical waveguide is wider than an upstream portion of the optical waveguide.

9. The photon detector of claim 1 , wherein the optical waveguide is vertically stacked with the superconducting wire.

10. The photon detector of claim 1 , further comprising a photon source coupled to the optical waveguide and configured to probabilistically generate photons.

11. The photon detector of claim 1 , wherein each wide portion includes a bend, and wherein an inside bend radius of each wide portion is equal to a width of the wide portion.

12. The photon detector of claim 1 , wherein the optical waveguide is positioned on a same layer as the superconducting wire.

13. A photon detector, comprising:
a superconducting wire having a plurality of alternating narrow and wide portions;
a current source electrically-coupled to the superconducting wire and configured to supply the superconducting wire with electrical current; and
an optical waveguide optically coupled to the plurality of narrow portions of the superconducting wire,
wherein:
the electrical current supplied by the current source is selected so as to maintain the superconducting wire in a superconducting state in the absence of incident photons from the optical waveguide,
the narrow portions of the superconducting wire are configured to transition from a superconducting state to a non-superconducting state in response to an incident photon from the optical waveguide, and
the wide portions are sized so as to remain in the superconducting state regardless of a state of the narrow portions.

14. The photon detector of claim 13 , wherein each narrow portion of the plurality of narrow portions is straight to reduce current crowding effects within the narrow portion.

15. The photon detector of claim 13 , wherein at least one wide portion of the plurality of wide portions is bent.

16. The photon detector of claim 13 , wherein the narrow portions each have a first width and the wide portions each have a second width, the second width being greater than the first width.

17. The photon detector of claim 13 , further comprising a readout circuit electrically-coupled to the superconducting wire and configured to measure an electrical property of the superconducting wire, wherein the electrical property is indicative of a number of photons incident to the superconducting wire.

18. The photon detector of claim 17 , wherein the electrical property comprises a voltage across the superconducting wire or an impedance of the superconducting wire.

19. The photon detector of claim 18 , wherein the readout circuit is configured to measure the voltage across a contact electrically-coupled in parallel with the superconducting wire.

20. The photon detector of claim 13 , wherein the optical waveguide is tapered to improve coupling, such that a downstream portion of the optical waveguide is wider than an upstream portion of the optical waveguide.

21. The photon detector of claim 13 , wherein the optical waveguide is vertically stacked with the superconducting wire.

22. The photon detector of claim 13 , further comprising a photon source coupled to the optical waveguide and configured to probabilistically generate photons.

23. The photon detector of claim 13 , wherein the optical waveguide is positioned on a same layer as the superconducting wire.

24. A photon detector, comprising:
a superconducting wire having a plurality of alternating narrow and wide portions;
a current source electrically-coupled to the superconducting wire and configured to supply the superconducting wire with electrical current; and
an optical waveguide optically coupled to the plurality of narrow portions of the superconducting wire,
wherein the superconducting wire is tapered between the narrow portions and the wide portions to reduce current crowding effects.

25. The photon detector of claim 24 , wherein each narrow portion of the plurality of narrow portions is straight to reduce current crowding effects within the narrow portion.

26. The photon detector of claim 24 , wherein at least one wide portion of the plurality of wide portions is bent.

27. The photon detector of claim 24 , wherein the narrow portions each have a first width and the wide portions each have a second width, the second width being greater than the first width.

28. The photon detector of claim 24 , further comprising a readout circuit electrically-coupled to the superconducting wire and configured to measure an electrical property of the superconducting wire, wherein the electrical property is indicative of a number of photons incident to the superconducting wire.

29. The photon detector of claim 28 , wherein the electrical property comprises a voltage across the superconducting wire or an impedance of the superconducting wire.

30. The photon detector of claim 29 , wherein the readout circuit is configured to measure the voltage across a contact electrically-coupled in parallel with the superconducting wire.

31. The photon detector of claim 24 , wherein the optical waveguide is tapered to improve coupling, such that a downstream portion of the optical waveguide is wider than an upstream portion of the optical waveguide.

32. The photon detector of claim 24 , wherein the optical waveguide is vertically stacked with the superconducting wire.

33. The photon detector of c

Assignees

• Psiquantum Corp

Inventors

• Najafi Faraz
• Dudley Eric
• Thompson Mark

Classifications

• G01J1/42 Primary

  using electric radiation detectors (optical or mechanical part G01J1/04; by comparison with a reference light or electric value G01J1/10) · CPC title

• G01J2001/442

  Single-photon detection or photon counting · CPC title

• G01J1/0407

  Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings · CPC title

• G01J1/44 Primary

  Electric circuits {(for command of an exposure part G03B7/02)} · CPC title

• G01J2001/4446

  Type of detector · CPC title