IP Library › Granted Patent US 12,504,495
Granted Patent B2
US 12,504,495 · App. 18/636,077 · Granted Dec 23, 2025

Rydberg-molecule-based microwave direction finding

Inventors: Dana Zachary Anderson (Boulder, CO); Haoquan Fan (Erie, CO); Ying-Ju Wang (Broomfield, CO); Eric Magnuson Bottomley (Broomfield, CO)
Assignee: ColdQuanta, Inc.
G01S3/46
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Quick Facts
Patent No.
US 12,504,495
App. No.
18/636,077
Granted
Dec 23, 2025
Kind
B2
Abstract

A probe laser beam causes molecules to transition from a ground state to an excited state. A control laser beam causes molecules in the excited state to transition to a laser-induced Rydberg state. Microwave lenses convert a microwave wavefront into respective microwave beams. The microwave beams are counter-propagated through molecules so as to create a microwave interference pattern of alternating maxima and minima. The microwave interference pattern is imposed on the probe beam as a probe transmission pattern. The propagation direction of the microwave wavefront can be determined from the translational position of the probe transmission pattern; the intensity of the microwave wavefront can be determined by the intensity difference between the minima and maxima of the probe transmission pattern.

Claims (37)

1 . A microwave direction finder for finding a direction of a microwave wavefront detectable in an environment, comprising:

a cell containing molecules capable of being laser-induced into a desired laser-induced Rydberg state;

a laser system that induces the desired laser-induced Rydberg state in at least a portion of the molecules, the laser system including:

a probe laser that provides a probe beam to the cell; and

a control laser that provides a control beam to the cell, wherein the probe beam and the control beam together provide the desired laser-induced Rydberg state to the molecules;

a microwave lens system that receives the microwave wavefront and converts the microwave wavefront into a microwave interference pattern upon the cell, the microwave interference pattern inducing a probe transmission pattern in the probe beam; and

an analysis system that determines a propagation direction of the microwave wavefront based on the probe transmission pattern.

2 . The microwave direction finder of claim 1 , wherein the probe beam transitions the portion of the molecules from a first state to a second state and wherein the control beam transitions the portion of the molecules from the second state to a third state, the third state being the desired laser-induced Rydberg state.

3 . The microwave direction finder of claim 1 , wherein the analysis system determines the propagation direction based on a position of the probe transmission pattern in the cell.

4 . The microwave direction finder of claim 1 , further comprising a controller that selects a microwave frequency to which direction finding is to be applied by changing a wavelength of the control beam.

5 . The microwave direction finder of claim 1 , wherein the analysis system determines an intensity of the microwave wavefront based on the probe transmission pattern.

6 . The microwave direction finder of claim 1 , wherein the molecules are cold atoms having an associated temperature below one millikelvin.

7 . The microwave direction finder of claim 1 , wherein the microwave lens system includes a plurality of microwave lenses.

8 . The microwave direction finder of claim 7 , wherein the microwave lenses have respective optical axes that are parallel to each other.

9 . A microwave direction finder, comprising:

a cell containing molecules;

a laser system that induces a Rydberg state in at least a portion of the molecules, including:

a probe laser that provides a probe beam; and

a control laser that provides a control beam to, together with the probe beam, induce the Rydberg state in the at least a portion of the molecules;

a microwave lens system that converts a microwave wavefront into a plurality of microwave beams having a phase difference such that the plurality of microwave beams form a microwave interference pattern in the cell, a position of the microwave interference pattern in the cell being based on a propagation direction of the microwave wavefront, the microwave interference pattern inducing a probe transmission pattern in the probe beam; and

an analysis system that determines the propagation direction of the microwave wavefront based on the probe transmission pattern.

10 . The microwave direction finder of claim 9 , wherein the probe beam transitions the portion of the molecules from a first state to a second state and wherein the control beam transitions the portion of the molecules from the second state to a laser-induced third state.

11 . The microwave direction finder of claim 9 , wherein the analysis system determines the propagation direction based on a position of the probe transmission pattern in the cell.

12 . The microwave direction finder of claim 9 , further comprising a controller that selects a microwave frequency to which direction finding is to be applied by changing a wavelength of the control beam.

13 . The microwave direction finder of claim 9 , wherein the analysis system determines an intensity of the microwave wavefront based on the probe transmission pattern.

14 . The microwave direction finder of claim 9 , wherein the microwave lens system includes a plurality of microwave lenses.

15 . A microwave direction-finding process comprising:

directing a probe laser beam through molecules contained in a cell to cause molecules to transition from a first state to a second state;

directing a control laser beam through the molecules to cause molecules to transition from the second state to a laser-induced third state;

using a microwave lens system, converting a microwave wavefront into a microwave interference pattern at the cell, a position of the microwave interference pattern at the cell being based on a propagation direction of the microwave wavefront, the microwave interference pattern inducing a probe transmission pattern in the probe laser beam; and

determining a propagation direction of the microwave wavefront based on a probe transmission pattern in the probe laser beam.

16 . The microwave direction-finding process of claim 15 , wherein the determining includes determining an intensity of the microwave wavefront based on the probe transmission pattern.

17 . The microwave direction-finding process of claim 15 , wherein the determining includes:

determines the propagation direction based on a position of the probe transmission pattern in the cell.

18 . The microwave direction-finding process of claim 15 , further comprising changing a microwave frequency to which direction finding is to be applied by changing a wavelength of the control laser beam.

19 . The microwave direction-finding process of claim 15 , wherein the microwave lens system includes a plurality of microwave lenses.

20 . The microwave direction-finding process of claim 19 , wherein the microwave lenses have respective optical axes that are parallel to each other.

Assignments (2)
MERGER AND CHANGE OF NAME Recorded Mar 24, 2026
From: COLDQUANTA, INC.; INFLEQTION QUANTUM, LLC
To: INFLEQTION QUANTUM, LLC
Reel/Frame 075202/0045 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 5, 2025
From: ANDERSON, DANA ZACHARY; FAN, HAOQUAN; WANG, YING-JU; BOTTOMLEY, ERIC MAGNUSON
To: COLDQUANTA, INC.
Reel/Frame 072166/0560 →
Continuity (3)
Continuation 17021033 · Sep 15, 2020
Provisional Application 63048302 · Jul 6, 2020
Related Publication 20240272262A1 · Aug 15, 2024
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