Chip-scale atomic beam generation system

Abstract

An exemplary embodiment of the present disclosure provides a chip-scale atomic beam system including an atomic vapor source, a plurality of conduits, and a propagation chamber. The atomic vapor source chamber may include an atomic vapor source configured to emit atomic vapor. The plurality of conduits may have a first end and a second end. The first end may be in fluid communication with the atomic vapor source chamber. The plurality of conduits may be configured to collimate the atomic vapor as it travels through the plurality of conduits from the first end to the second end. The propagation chamber may be in fluid communication with the second ends of the plurality of conduits. The propagation chamber may have an internal pressure lower than an internal pressure of the atomic vapor source chamber to allow the collimated atomic vapor to propagate through the propagation chamber.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Application No. 63 / 302,308, filed January 24, 2022, which is incorporated by reference in its entirety as if fully set forth below.

[0002] (Government License Rights) This invention was made with Government support under Contract No. N00014-20-1-2429 awarded by the Office of Naval Research. The Government has certain rights in this invention.

[0003] (Technical field) Various embodiments of the present disclosure relate generally to systems and methods for generating atomic beams. [Background technology]

[0004] Systems that generate atomic beams have been a long-standing technology for atom-based sensors and clocks. Conventional atomic beam generating systems, such as Cs beam tubes for atomic clocks, exist in either laboratory-scale vacuum systems or custom vacuum tubes. Such Cs beam atomic clocks are widely used in communication systems. However, these conventional systems are often too large for certain applications and rely on complex manufacturing techniques. Thus, there is a need for improved atomic beam generating systems that are easier to manufacture and / or more compact than conventional systems. The embodiments disclosed herein provide such systems. Summary of the Invention

[0005] An exemplary embodiment of the present disclosure provides a chip-scale atomic beam system comprising an atomic vapor source, a plurality of conduits, and a propagation chamber. The atomic vapor source chamber may comprise an atomic vapor source configured to emit atomic vapor. The plurality of conduits may have a first end and a second end. The first end may be in fluid communication with the atomic vapor source chamber. The plurality of conduits may be configured to collimate the atomic vapor as it travels through the plurality of conduits from the first end to the second end. The propagation chamber may be in fluid communication with the second ends of the plurality of conduits. The propagation chamber may have an internal pressure lower than an internal pressure of the atomic vapor source chamber to allow the collimated atomic vapor to propagate through the propagation chamber.

[0006] In any of the embodiments disclosed herein, the system may further include one or more passive pumps configured to reduce the internal pressure of the propagation chamber below the internal pressure of the atomic vapor source chamber.

[0007] In any of the embodiments disclosed herein, the one or more passive pumps may include one or more non-evaporable getter pumps.

[0008] In any of the embodiments disclosed herein, the one or more passive pumps may include graphite.

[0009] In any of the embodiments disclosed herein, the atomic vapor source may contain alkali atoms, alkaline earth atoms, or molecules thereof.

[0010] In any of the embodiments disclosed herein, the atomic vapor source may contain rubidium.

[0011] In any of the embodiments disclosed herein, the atomic vapor source may be configured to emit atomic vapor upon thermal or optical stimulation.

[0012] In any of the embodiments disclosed herein, the system may include a laminate of one or more layers bonded together.

[0013] In any of the embodiments disclosed herein, the stack may include at least one silicon layer bonded to at least one glass layer.

[0014] In any of the embodiments disclosed herein, the plurality of conductive paths may be formed in the at least one silicon layer.

[0015] In any of the embodiments disclosed herein, the one or more layers may be joined by anodic or fusion bonding.

[0016] In any of the embodiments disclosed herein, the top and bottom of the one or more layers may be transparent.

[0017] In any of the embodiments disclosed herein, the plurality of conduits may have an aspect ratio of 1:1 to 1:100,000.

[0018] In any of the embodiments disclosed herein, the interior including the atomic vapor source chamber, the plurality of conduits, and the propagation chamber may be hermetically sealed.

[0019] In any of the embodiments disclosed herein, the system may be configured as an atomic clock.

[0020] In any of the embodiments disclosed herein, the system may be configured as an atom interferometer.

[0021] In any of the embodiments disclosed herein, the plurality of conduits may have an orientation configured to generate a desired atomic flux.

[0022] In any of the embodiments disclosed herein, the multiple conduits may be parallel to one another.

[0023] Another embodiment of the present disclosure provides a chip-scale atomic beam system comprising a first chamber, a second chamber, and a plurality of conduits. The first chamber may include an atomic vapor source therein. The first chamber may have a first internal pressure. The second chamber may have an interior. The second chamber may have a second internal pressure lower than the first internal pressure to create a pressure differential between the first chamber and the second chamber. The plurality of conduits may have a first end and a second end. The first end may be in fluid communication with the first chamber. The second end may be in fluid communication with the second chamber.

[0024] In any of the embodiments disclosed herein, a pressure differential between the first chamber and the second chamber may cause atomic vapor released from the atomic vapor source to travel from the first chamber through the multiple conduits to the second chamber.

[0025] In any of the embodiments disclosed herein, the system may further include one or more passive pumps configured to at least partially create a pressure differential between the first chamber and the second chamber.

[0026] In any of the embodiments disclosed herein, the first chamber, the plurality of conduits, and the second chamber may be at least partially comprised of a laminate of one or more layers bonded together.

[0027] In any of the embodiments disclosed herein, the first chamber, the second chamber, and the interior of the plurality of conduits may be hermetically sealed.

[0028] These and other aspects of the present disclosure are described below in the Detailed Description of the Invention and in the accompanying drawings. Other aspects and features of the embodiments will become apparent to those skilled in the art upon review of the following description of certain exemplary embodiments in conjunction with the drawings. Although features of the present disclosure may be described in conjunction with certain embodiments and drawings, all embodiments of the present disclosure may include one or more of the features described herein. Furthermore, although one or more embodiments may be described as having certain advantageous features, one or more of such features may also be used with various embodiments described herein. Similarly, although exemplary embodiments may be described below as device, system, or method embodiments, it should be understood that such exemplary embodiments may be implemented in various devices, systems, and methods of the present disclosure. [Brief description of the drawings]

[0029] The following detailed description of certain embodiments of the present disclosure will be better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the present disclosure, certain embodiments are shown in the drawings. It should be understood, however, that the disclosure is not limited to the precise arrangements and instrumentalities of the embodiments shown in the drawings.

[0030] [Figure 1] FIG. 1 is a schematic diagram of a chip-scale atomic beam system according to an exemplary embodiment of the present disclosure.

[0031] [Diagram 2] FIG. 2 is a schematic cross-sectional view of a chip-scale atomic beam system according to an exemplary embodiment of the present disclosure taken along line LL in FIG.

[0032] [Diagram 3] FIG. 3 is a schematic diagram of a chip-scale atomic beam system according to an exemplary embodiment of the present disclosure.

[0033] [Figure 4] 4 is a plot of a Rb fluorescence spectrum showing the lateral velocity distribution of an atomic beam generated by a chip-scale atomic beam system according to an exemplary embodiment of the present disclosure, and a Rb absorption spectrum showing the density of Rb vapor fed into the guide array, with a saturated absorption spectrum from a natural abundance Rb cell shown for reference. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0034] In order to facilitate the understanding of the principles and features of the present disclosure, various exemplary embodiments are described below. The components, steps, and materials described below as constituting various elements of the embodiments disclosed herein are intended to be illustrative and not limiting. Many suitable components, steps, and materials that will perform the same or similar functions as the components, steps, and materials described herein are intended to be encompassed within the scope of the present disclosure. Such other components, steps, and materials not described herein include, but are not limited to, similar components or steps developed after the development of the embodiments disclosed herein.

[0035] As shown in FIG. 1, an exemplary embodiment of the present disclosure provides a chip-scale atomic beam system including an atomic vapor source 106, a plurality of conduits 110, and a propagation chamber 115. The atomic vapor source chamber 105 may include an atomic vapor source 106 configured to emit atomic vapor. The atomic vapor source 106 may be configured to emit atomic vapor when thermally and / or optically stimulated. The atomic vapor source 106 may be, for example, any elemental metal or chemical compound that outputs atomic vapor when thermally or optically stimulated. In some embodiments of the present disclosure, the atomic vapor source 106 contains alkali atoms, alkaline earth atoms, or molecules thereof. In some embodiments, the atomic vapor source 106 may contain rubidium, such as a rubidium pill.

[0036] The plurality of conduits 110 may have a first end and a second end. The first end may be in fluid communication with the atomic vapor source chamber 105. The plurality of conduits 110 may be configured to collimate the atomic vapor as it travels through the plurality of conduits from the first end to the second end. The plurality of conduits 110 may have an aspect ratio in the range of 1:1 to 1:100,000. The plurality of conduits 110 may have an orientation configured to generate a desired atomic flux. In some embodiments, the plurality of conduits 110 may be substantially parallel to one another as shown in FIG. 1.

[0037] As shown in FIG. 3, in some embodiments, the system may include two or more cascaded groups of conduits 110 and 111. The groups of conduits 110 and 111 may be separated by an additional chamber 130. Thus, atomic vapor generated from the atomic vapor source 106 in the atomic vapor source chamber 105 may flow through a first group of conduits 110, through the additional chamber 130, through a second group of conduits 111, and into the propagation chamber 115. Due to the presence of multiple groups of conduits 110 and 111, the atomic vapor is more collimated when it reaches the propagation chamber. The flow of atomic vapor is represented by the arrows shown in FIG. 1 and FIG. 3.

[0038] The propagation chamber 115 may be in fluid communication with a second end of the plurality of conduits 110. Thus, atomic vapor generated from the atomic vapor source 106 in the atomic vapor source chamber 105 may propagate from the atomic vapor source chamber 105 through the plurality of conduits 110 while being collimated by the plurality of conduits 110 to the propagation chamber 115.

[0039] The flow of atomic vapor can be caused by a pressure difference between the atomic vapor source chamber 105 and the propagation chamber 115. In particular, the propagation chamber can have an internal pressure lower than the internal pressure of the atomic vapor source chamber 105 so that the collimated atomic vapor can propagate through the propagation chamber 115. This pressure difference can be caused by one or more pumps that evacuate residual gases and maintain a vacuum. The pumps can be passive pumps that are configured to lower the internal pressure of the propagation chamber below the internal pressure of the atomic vapor source chamber 105. In some embodiments, the pumps can be passive pumps, including but not limited to non-evaporable getter pumps 125, graphite 120, and combinations thereof. As shown in FIG. 1, the one or more pumps can include a non-evaporable getter pump 125 and a graphite rod 120. As shown in FIG. 3, if an additional chamber 130 is used, the additional chamber can also include a pump, such as a graphite rod 120.

[0040] The pressure difference between the propagation chamber 115 and the atomic vapor source chamber 105 may also be maintained in part by hermetically sealing the apparatus. For example, in some embodiments, the interior including the atomic vapor source chamber 105, the plurality of conduits 110, and the propagation chamber 115 may be hermetically sealed and evacuated.

[0041] FIG. 2 is a cross-sectional view taken along line LL in FIG. 1. As shown in FIG. 2, a portion of an atomic beam system may include a stack of one or more layers 150, 155 bonded together. The layers 150, 155 can be composed of many different materials known in the art. In some embodiments, the stack may include at least one silicon layer 150 bonded to at least one glass layer 155. In some embodiments, as shown in FIG. 2, the stack may include multiple silicon layers 150 and glass layers 155 bonded together. The one or more layers 150, 155 may be bonded together. Many different bonding techniques may be employed, including but not limited to anodic bonding, fusion bonding, and the like.

[0042] In some embodiments, the plurality of conduits 110 may be formed in at least one silicon layer 150 within the stack, as shown in FIG. 2. The plurality of conduits 110 may be formed in a variety of ways, including by etching, machining, and the like. In some embodiments, the plurality of conduits 110 may be substantially coplanar within the silicon layer 150, as shown in FIG. 2. However, the present disclosure is not so limited. Rather, in some embodiments, the plurality of conduits 110 may not be coplanar. For example, adjacent conduits may be vertically offset from one another. In some embodiments, the plurality of conduits 110 may consist of multiple rows of conduits in the same layer or different layers within the stack.

[0043] In some embodiments, the top and / or bottom of one or more of the layers may be transparent, such as transparent glass. The top and / or bottom layers may be composed of a material that allows the atomic beam to be inspected within the propagation chamber 115. The beam inspection process within the propagation chamber 115 may be performed, for example, using an external electromagnetic field.

[0044] Initial characterization of the exemplary atomic beam system was performed using absorption spectroscopy, as shown in FIG. 4, and found that a beam was formed and the system maintained a vacuum level.

[0045] The atomic beach system disclosed herein can be used in a variety of applications. In some embodiments, the system can be configured as an atomic clock. For example, an atomic clock can be created by introducing a laser beam at two or more positions in a propagation chamber through which a collimated atomic beam propagates. Atomic transitions can be probed using isolated oscillating field techniques. Atomic fluorescence can be collected to measure the effect of the oscillating field. The fluorescence signal can be used to stabilize an oscillator that drives the oscillating field.

[0046] In some embodiments, the system may be configured as an atom interferometer. For example, an atom interferometer can be created by introducing three or more laser beams into a propagation chamber through which a collimated atomic beam propagates. With three laser beams, a Mach-Zehnder atom interferometer can be realized. Atomic fluorescence can be collected to measure the atomic state near the end of the propagation chamber. The atomic state can be inferred from the collected data.

[0047] The following describes an exemplary process that can be used to fabricate the atomic beam system disclosed herein: Silicon and glass wafers can be etched or machined to form a cavity suitable for atom delivery, collimation, and atomic beam propagation. The silicon and glass layers can be anodically bonded (except for the final layer). The atomic vapor source (e.g., Rb pills) and pump (e.g., non-evaporable getter, graphite rod) can be inserted. The system, with the stack containing all of the components and one unbonded interface, can be placed on a heated platform in a vacuum chamber. The system can be heated to near 100° C. to evacuate residual gases from the components. The non-evaporable getter pump can be thermally activated. The final layer can be bonded to the other layers. The system can be removed from the vacuum chamber. Finally, the atomic vapor source chamber can be heated, for example to 100° C., and the atomic vapor source can be laser activated (e.g., to temperatures of about 400-700° C.) to achieve high absorption in the atomic source region.

[0048] It is to be understood that the embodiments and claims disclosed herein are not limited in their application to the details of construction and arrangement of the components described herein and illustrated in the drawings. Rather, the specification and drawings provide examples of possible embodiments. The embodiments and claims disclosed herein are capable of further embodiments and can be practiced and carried out in various ways. It is also to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be construed as limiting the scope of the claims.

[0049] As such, those skilled in the art will appreciate that the conception underlying the present application and claims may be readily utilized as a basis for the designing of other structures, methods and systems for carrying out the purposes of the embodiments and claims presented herein, and it is important that the claims be regarded as including such equivalent constructions.

[0050] Furthermore, the purpose of the Abstract is to enable the U.S. Patent and Trademark Office and the general public, including those not familiar with patent and legal terminology and language, to quickly grasp the content and gist of the technical disclosure of the application upon a single reading. The Abstract does not define the scope of the claims of the application, nor does it limit the scope of the claims in any way.

Claims

1. An atomic beam system disposed on a chip or chip-scale substrate, comprising: an atomic vapor source chamber disposed on the chip or chip-scale substrate and configured to emit atomic vapor containing atoms used to generate a thermal atomic beam from the atomic vapor; a plurality of conduits disposed on the chip or chip-scale substrate, the conduits having a length from a first end to a second end, the first end being in fluid communication with the atomic vapor source chamber, the plurality of conduits being configured to passively collimate the atomic vapor as it travels along the length of the plurality of conduits to produce the thermal atomic beam; a propagation chamber disposed on the chip or chip-scale substrate and in fluid communication with the second ends of the plurality of conduits, the propagation chamber configured to have an internal pressure lower than an internal pressure of the atomic vapor source chamber such that the thermal atomic beam is able to propagate freely through the propagation chamber; The atomic beam system is configured to enable the thermal atomic beam to be observed during free propagation.

2. further comprising one or more passive pumps configured to reduce the internal pressure of the propagation chamber below the internal pressure of the atomic vapor source chamber; 10. The atomic beam system of claim 1, wherein the passive collimation of the atomic vapor is based, at least in part, on one or more characteristics of the plurality of guides.

3. The atomic beam system of claim 2 , wherein the one or more passive pumps include one or more non-evaporable getter pumps.

4. The atomic beam system of claim 2 , wherein the one or more passive pumps comprise graphite.

5. the atomic vapor source chamber comprising an atomic vapor source configured to emit the atomic vapor; 5. The atomic beam system according to claim 1, wherein the atoms include alkali atoms, alkaline earth atoms, or molecules thereof.

6. 6. The atomic beam system of claim 5, wherein the atomic vapor source contains rubidium.

7. 5. The atomic beam system of claim 1, wherein the atomic vapor source is configured to emit atomic vapor when thermally or optically stimulated.

8. 5. An atomic beam system according to claim 1, further comprising a stack of one or more layers bonded together.

9. 9. The atomic beam system of claim 8, wherein the stack comprises at least one silicon layer bonded to at least one glass layer.

10. 10. The atomic beam system of claim 9, wherein the plurality of conduits are formed in the at least one silicon layer.

11. The atomic beam system of claim 8 , wherein the one or more layers are bonded by anodic or fusion bonding.

12. 9. The atomic beam system of claim 8, wherein a top layer and a bottom layer of the one or more layers are transparent.

13. 5. The atomic beam system according to claim 1, wherein the plurality of guides have an aspect ratio of 1:1 to 1:100,000.

14. 5. The atomic beam system of claim 1, wherein the interior including the atomic vapor source chamber, the plurality of conduits, and the propagation chamber is hermetically sealed.

15. 5. The atomic beam system according to claim 1, configured as an atomic clock.

16. 5. An atomic beam system according to claim 1, configured as an atom interferometer.

17. 5. The atomic beam system according to claim 1, wherein the plurality of guide paths are parallel to one another.

18. An atomic beam system disposed on a chip or chip-scale substrate, comprising: a first chamber having an interior with an atomic vapor source configured to emit atomic vapor used to generate a thermal atomic beam, the first chamber having a first internal pressure and disposed on the chip or chip-scale substrate; a second chamber having an interior, the second chamber having a second internal pressure lower than the first internal pressure to create a pressure differential between the first chamber and the second chamber, allowing the thermal atomic beam to propagate freely through the second chamber, the second chamber being disposed on the chip or chip-scale substrate; a plurality of conduits having a first end and a second end, the first end in fluid communication with the first chamber and the second end in fluid communication with the second chamber; the plurality of conductive paths are disposed on the chip or chip-scale substrate and have a length from the first end to the second end; the plurality of conduits have an orientation configured to generate a desired atomic flux and are configured to passively collimate the atomic vapor as it travels from the first chamber along the length of the plurality of conduits to generate the thermal atomic beam; the one or more passive pumps are selected from the group consisting of one or more non-evaporable getter pumps, one or more pumps comprising graphite, and combinations thereof, and the one or more pumps are configured to reduce the internal pressure of the second chamber below the internal pressure of the first chamber; the atomic beam system is configured to enable the thermal atomic beam to be observed during free propagation; An atomic beam system, wherein passive collimation of the atomic vapor is based, at least in part, on one or more characteristics of the plurality of guides.

19. 20. The atomic beam system of claim 18, wherein the atomic vapor source contains alkali atoms, alkaline earth atoms, or molecules thereof.

20. 20. The atomic beam system of claim 18, wherein the atomic vapor source contains rubidium.

21. 21. The atomic beam system of claim 18, wherein the first chamber, the plurality of conduits, and the second chamber are at least partially constructed from a stack of one or more layers bonded together.

22. 22. The atomic beam system of claim 21, wherein the stack comprises at least one silicon layer bonded to at least one glass layer.

23. 23. The atomic beam system of claim 22, wherein the plurality of conduits are formed in the at least one silicon layer.

24. 21. An atomic beam system according to any one of claims 18 to 20, wherein the plurality of guides have an aspect ratio of 1:1 to 1:100,000.

25. 21. An atomic beam system according to any one of claims 18 to 20, configured as an atomic clock or an atomic interferometer.

26. An atomic beam system disposed on a chip or chip-scale substrate, comprising: an atomic vapor source chamber configured to emit atomic vapor containing atoms used to generate a thermal atomic beam from the atomic vapor; a plurality of conduits having a length from a first end to a second end, the first end being in fluid communication with the atomic vapor source chamber and configured to passively collimate the atomic vapor as it travels along the length of the plurality of conduits to produce the thermal atomic beam; a propagation chamber in fluid communication with the second ends of the plurality of conduits, the propagation chamber configured to have an internal pressure lower than an internal pressure of the atomic vapor source chamber such that the thermal atomic beam is able to propagate freely through the propagation chamber; one or more pumps configured to reduce the internal pressure of the propagation chamber below the internal pressure of the atomic vapor source chamber; the atomic beam system is configured to enable the thermal atomic beam to be observed during free propagation; the passive collimation of the atomic vapor is based, at least in part, on one or more characteristics of the plurality of conduits; An atomic beam system wherein the one or more pumps are selected from the group consisting of one or more passive non-evaporable getter pumps, one or more passive pumps comprising graphite, and combinations thereof.

27. A method for generating a thermal atomic beam using an atomic beam system disposed on a chip or chip-scale substrate, comprising: stimulating an atomic vapor source to emit atomic vapor in a first chamber having a first internal pressure; passively collimating the atomic vapor in an array of multiple guideways to produce the thermal atomic beam; and observing the freely propagating thermal atomic beam in a second chamber having a second internal pressure lower than the first internal pressure so as to create a pressure differential between the first chamber and the second chamber.

28. The method of claim 27, further comprising the step of creating a pressure differential between the first chamber and the second chamber.

29. A method as described in claim 27 or claim 28, wherein the array of multiple guide paths are parallel to each other.

30. A method as described in claim 27 or claim 28, wherein the stimulating is thermal stimulating or optical stimulating.

31. A method as described in claim 27 or claim 28, wherein the array of multiple guides has an aspect ratio of 1:1 to 1:100,000.

32. The method described in claim 27 or claim 28, wherein the interiors of the first chamber, the second chamber, and the array of multiple conduits are hermetically sealed.

33. The method described in claim 28, wherein the step of creating a pressure differential includes using one or more passive pumps configured to at least partially create a pressure differential between the first chamber and the second chamber.

34. The method of claim 33, wherein the one or more passive pumps include one or more non-evaporative getter pumps.

35. The method of claim 33, wherein the one or more passive pumps comprise graphite.

36. A method for generating a thermal atomic beam using an atomic beam system disposed on a chip or chip-scale substrate, comprising: stimulating an atomic vapor source containing alkali atoms, alkaline earth atoms, or molecules thereof to emit atomic vapor in a first chamber having a first internal pressure; passively collimating the atomic vapor in an array of multiple guideways to produce the thermal atomic beam; observing the freely propagating thermal atomic beam in a second chamber having a second internal pressure; creating a pressure differential between the first chamber and the second chamber; the second chamber has a second internal pressure lower than the first internal pressure; the step of creating a pressure differential includes using one or more passive pumps configured to at least partially create a pressure differential between the first chamber and the second chamber; The method, wherein the one or more pumps are selected from the group consisting of one or more non-evaporable getter pumps, one or more pumps comprising graphite, and combinations thereof.

37. A method for producing an atomic beam system, the method comprising: stimulating an atomic vapor source to emit atomic vapor in a first chamber of an atomic beam system disposed on a chip or chip-scale substrate, the first chamber having a first internal pressure; passively collimating the atomic vapor to produce a thermal atomic beam in an array of multiple guideways in the atomic beam system; observing the freely propagating thermal atomic beam in a second chamber of the atomic beam system; creating a pressure differential between the first chamber and the second chamber; the second chamber has a second internal pressure lower than the first internal pressure; the step of creating a pressure differential includes using one or more passive pumps configured to at least partially create a pressure differential between the first chamber and the second chamber; The method, wherein the one or more pumps are selected from the group consisting of one or more passive non-evaporable getter pumps, one or more passive pumps comprising graphite, and combinations thereof.

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