Controlling electric fields in vapor cells having a body defined by a stack of layers
In a general aspect, a vapor cell includes a body defined by a stack of layers that includes electrically conductive layers and electrically insulating layers. The stack of layers are bonded to each other and have first and second end layers at respective opposite ends of the body. The stack of layers also has intermediate layers between the first and second end layers that define an internal cavity of the body. The internal cavity extends through the body between the first and second end layers and includes a vapor or a source of the vapor disposed therein. Adjacent electrically conductive layers are separated by at least one electrically insulating layer. Moreover, each electrically conductive layer defines an electrode of the vapor cell and includes a contact surface on an exterior side of the body. The contact surface defines an electrical contact of the electrode.
1. A vapor cell, comprising:
a body defined by a stack of layers that comprises electrically conductive layers and electrically insulating layers, the stack of layers bonded to each other and having:
first and second end layers at respective opposite ends of the body, one or both of the first and second end layers being optically transparent, and
intermediate layers between the first and second end layers that define an internal cavity of the body, the internal cavity extending through the body between the first and second end layers, and
one or more internal surfaces that bound the internal cavity, at least a portion of the one or more internal surfaces covered by a coating that is chemically inert to a vapor of the vapor cell.
wherein adjacent electrically conductive layers are separated by at least one electrically insulating layer, and
wherein each electrically conductive layer defines an electrode of the vapor cell and comprises a contact surface on an exterior side of the body, the contact surface defining an electrical contact of the electrode; and
the vapor or a source of the vapor, disposed in the internal cavity.
2. The vapor cell of claim 1 , wherein at least a portion of the stack of layers alternates between electrically conductive and electrically insulating layers.
3. The vapor cell of claim 2 , wherein the entire stack of layers alternates between electrically conductive and electrically insulating layers.
4. The vapor cell of claim 1 , wherein the first and second end layers are electrically conductive layers and define, respectively, first and second end electrodes of the vapor cell.
5. The vapor cell of claim 1 ,
wherein each intermediate layer comprises an inner perimeter surface that defines part of the internal cavity; and
wherein the inner perimeter surface of at least one electrically conductive layer is configured to allow the electrically conductive layer to protrude into the internal cavity past layers in the stack that are adjacent the electrically conductive layer.
6. The vapor cell of claim 1 ,
wherein each intermediate layer comprises an outer perimeter surface that defines part of the exterior side of the body; and
wherein the outer perimeter surface of at least one electrically conductive layer is configured to allow the electrically conductive layer to protrude from the exterior side past layers in the stack that are adjacent the electrically conductive layer.
7. The vapor cell of claim 1 ,
wherein at least one electrically conductive layer is partitioned into a plurality of sections to define respective segments of a segmented electrode; and
wherein the contact surface of the at least one electrically conductive layer is partitioned into a plurality of section contact surfaces, each section contact surface defining an electrical contact of a respective one of the segments.
8. The vapor cell of claim 7 , wherein the plurality of sections are electrically isolated from each other.
9. The vapor cell of claim 7 , wherein the plurality of section contact surfaces are configured such that each is impedance matched to a source of radio frequency electromagnetic radiation.
10. The vapor cell of claim 1 , wherein one or more layers in the stack are planar layers.
11. The vapor cell of claim 1 , wherein at least one electrically conductive layer comprises:
a substrate; and
an electrically conductive coating that covers at least part of the substrate and has a first portion exposed to the interior cavity and a second portion defining the contact surface of the electrically conductive layer.
12. The vapor cell of claim 11 , wherein the substrate is formed of an electrically insulating material.
13. The vapor cell of claim 11 , wherein the at least one electrically conductive layer further comprises:
an electrically insulating coating disposed over the electrically conductive coating and covering at least the first portion thereof.
14. The vapor cell of claim 1 , wherein the portion of the one or more internal surfaces comprises all internal surfaces associated with the electrically conductive layers.
15. The vapor cell of claim 1 ,
wherein the vapor cell comprises the source of the vapor;
wherein the intermediate layers define a wall encircling a first portion of the internal cavity; and
wherein the internal cavity comprises a second portion that extends into the wall from the first portion and contains the source of the vapor.
16. The vapor cell of claim 1 ,
wherein the body comprises a first exterior side and a second exterior side;
wherein at least one electrically conductive layer comprises first and second tabs extending outward from, respectively, the first and second exterior sides; and
wherein one or both of the first and second tabs define the contact surface of the electrically conductive layer.
17. The vapor cell of claim 1 , wherein the electrically conductive layers are formed of a material having a resistivity less than 10 3 W-cm.
18. The vapor cell of claim 1 , wherein at least one electrically conductive layer is formed of doped silicon.
19. The vapor cell of claim 1 , wherein at least one electrically conductive layer is formed of a transparent conducting oxide.
20. The vapor cell of claim 1 , wherein at least one electrically conductive layer is formed of a metal or metal alloy.
21. The vapor cell of claim 1 , wherein the electrically insulating layers are formed of a material having a resistivity greater than 106 W-cm.
22. The vapor cell of claim 1 , wherein at least one electrically insulating layer is formed of a glass comprising silicon oxide.
23. The vapor cell of claim 1 , wherein the stack of layers comprises an adhesion layer at an interface between a pair of adjacent layers in the stack.
24. The vapor cell of claim 1 , wherein one or both of the first and second end layers comprise a reflective coating.
25. The vapor cell of claim 1 , wherein one or both of the first and second end layers comprise an anti-reflective coating.
26. The vapor cell of claim 1 , wherein the one or more internal surfaces are covered, at least in part, by an anti-relaxation coating.
27. The vapor cell of claim 26 , wherein the anti-relaxation coating comprises a hydrocarbon material.
28. The vapor cell of claim 1 , wherein one or both of the first and second end layers comprises an interior surface covering an opening of the internal cavity adjacent the end layer, the interior surface having an optical filter coating disposed thereon.
29. The vapor cell of claim 1 , wherein the vapor comprises a gas of Rydberg atoms.