Ramsey-Bordé ion frequency-reference apparatus, and methods of making and using the same

Patent metadata

Field	Value
Publication number	US-11929186-B2
Application number	US-202318120787-A
Country	US
Kind code	B2
Filing date	Mar 13, 2023
Priority date	Mar 10, 2021
Publication date	Mar 12, 2024
Grant date	Mar 12, 2024

Abstract

In some variations, an interferometric frequency-reference apparatus comprises: an atom source configured to supply neutral atoms; a collimator configured to form a collimated beam of the neutral atoms; one or more probe lasers; and a Doppler laser configured to determine a ground-state population of the neutral atoms. Other variations provide a method of creating a stable frequency reference, comprising: forming a collimated beam of neutral atoms; illuminating the neutral atoms with first and second probe lasers; adjusting the frequencies of the first probe laser and second probe laser using Ramsey spectroscopy to an S→D transition of the neutral atoms; and determining a ground-state population of the neutral atoms with another laser. The interferometric frequency-reference apparatus may provide an optical frequency reference or a microwave frequency reference.

First claim

What is claimed is:

1. An interferometric frequency-reference apparatus, said apparatus comprising:
a vacuum chamber;
an atom source configured to supply neutral atoms;
a collimator configured to form a collimated beam of said neutral atoms;
one or more probe lasers, wherein said one or more probe lasers are configured to probe quadrupole or both dipole and quadrupole transitions of said neutral atoms; and
a readout laser configured to determine a ground-state population of said neutral atoms,
wherein said atom source and said collimator are disposed within said vacuum chamber.

2. The interferometric frequency-reference apparatus of claim 1 , wherein said atom source is a solid-state electrochemical atom source.

3. The interferometric frequency-reference apparatus of claim 1 , wherein said collimator is a linear collimator.

4. The interferometric frequency-reference apparatus of claim 1 , wherein said one or more probe lasers are configured for Ramsey spectroscopy on said neutral atoms.

5. The interferometric frequency-reference apparatus of claim 1 , wherein said one or more probe lasers is two or more probe lasers.

6. The interferometric frequency-reference apparatus of claim 1 , wherein said interferometric frequency-reference apparatus further comprises a cooling laser.

7. The interferometric frequency-reference apparatus of claim 1 , wherein said readout laser is further configured for cooling.

8. The interferometric frequency-reference apparatus of claim 1 , wherein said interferometric frequency-reference apparatus further comprises an imaging system configured to focus fluorescence from said neutral atoms.

9. The interferometric frequency-reference apparatus of claim 1 , wherein said interferometric frequency-reference apparatus provides an optical frequency reference.

10. The interferometric frequency-reference apparatus of claim 1 , wherein said interferometric frequency-reference apparatus provides a microwave frequency reference.

11. A method of creating a stable frequency reference, said method comprising:
(a) creating an atomic vapor of neutral atoms;
(b) collimating said neutral atoms in a collimator, to form a collimated beam of said neutral atoms;
(c) optionally, illuminating some of said neutral atoms with a cooling laser;
(d) illuminating at least some of said neutral atoms with a first probe laser at a first-probe-laser frequency;
(e) illuminating at least some of said neutral atoms with a second probe laser at a second-probe-laser frequency;
(f) adjusting said first-probe-laser frequency and said second-probe-laser frequency using Ramsey spectroscopy to an S→D transition of at least some of said neutral atoms; and
(g) illuminating at least some of said neutral atoms with a readout laser to determine a ground-state population of said neutral atoms.

12. The method of claim 11 , wherein said neutral atoms are obtained from a solid-state electrochemical atom source.

13. The method of claim 11 , wherein step (c) is conducted to cool said neutral atoms in preparation for said Ramsey spectroscopy.

14. The method of claim 11 , wherein said collimator is a linear collimator.

15. The method of claim 11 , wherein said method further comprises illuminating at least some of said neutral atoms with a third probe laser.

16. The method of claim 15 , wherein said method further comprises illuminating at least some of said neutral atoms with a fourth probe laser after said illuminating at least some of said neutral atoms with said third probe laser.

17. The method of claim 11 , wherein said method is continuous.

18. The method of claim 11 , wherein said stable frequency reference is an optical frequency reference.

19. The method of claim 11 , wherein said stable frequency reference is a microwave frequency reference.

20. An interferometric frequency-reference apparatus, said apparatus comprising:
a vacuum chamber;
an atom source configured to supply neutral atoms;
a collimator configured to form a collimated beam of said neutral atoms;
one or more probe lasers;
a readout laser configured to determine a ground-state population of said neutral atoms; and
a cooling laser,
wherein said atom source and said collimator are disposed within said vacuum chamber.

21. The interferometric frequency-reference apparatus of claim 20 , wherein said atom source is a solid-state electrochemical atom source.

22. The interferometric frequency-reference apparatus of claim 20 , wherein said collimator is a linear collimator.

23. The interferometric frequency-reference apparatus of claim 20 , wherein said one or more probe lasers are configured for Ramsey spectroscopy on said neutral atoms.

24. The interferometric frequency-reference apparatus of claim 20 , wherein said interferometric frequency-reference apparatus further comprises an imaging system configured to focus fluorescence from said neutral atoms.

25. The interferometric frequency-reference apparatus of claim 20 , wherein said interferometric frequency-reference apparatus provides an optical frequency reference.

26. The interferometric frequency-reference apparatus of claim 20 , wherein said interferometric frequency-reference apparatus provides a microwave frequency reference.

Assignees

• Hrl Lab Llc

Inventors

• Autry Travis
• Counts Ian
• Ellis Jennifer
• Kim Danny
• Roper Christopher

Classifications

• G21K1/30

  for confining neutral particles or handling confined neutral particles, e.g. atom traps · CPC title

• H03L7/26

  using energy levels of molecules, atoms, or subatomic particles as a frequency reference · CPC title

• G01C19/62

  with optical pumping · CPC title

• G21K1/02 Primary

  using diaphragms, collimators · CPC title

• G21K1/006

  Physics · mapped topic