Systems and methods for a wafer scale atomic clock

Patent metadata

Field	Value
Publication number	US-9312869-B2
Application number	US-201314059698-A
Country	US
Kind code	B2
Filing date	Oct 22, 2013
Priority date	Oct 22, 2013
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

Systems and methods for a wafer scale atomic clock are provided. In at least one embodiment, a wafer scale device comprises a first substrate; a cell layer joined to the first substrate, the cell layer comprising a plurality of hermetically isolated cells, wherein separate measurements are produced for each cell in the plurality of hermetically isolated cells; and a second substrate joined to the cell layer, wherein the first substrate and the second substrate comprise electronics to control the separate measurements, wherein the separate measurements are combined into a single measurement.

First claim

What is claimed is:

1. A wafer scale device, the wafer scale device comprising:
a first substrate;
a cell layer joined to the first substrate, the cell layer comprising a plurality of hermetically isolated cells, wherein separate measurements are produced for each cell in the plurality of hermetically isolated cells; and
a second substrate joined to the cell layer opposite the first substrate, wherein the first substrate and the second substrate comprise electronics to control the separate measurements, wherein the separate measurements are combined into a single measurement.

2. The wafer scale device of claim 1 , wherein the first substrate comprises:
an electronics layer; and
a light source layer joined to the first electronics layer, wherein electronics in the electronics layer control the emission of light from at least one light source in the light source layer, wherein the at least one light source interrogates matter in separate cells in the plurality of hermetically isolated cells.

3. The wafer scale device of claim 2 , wherein the matter comprises at least one of:
alkali atoms; and
one or more buffer gases.

4. The wafer scale device of claim 2 , wherein the first substrate further comprises at least one of
a quarter wave plate layer configured to circularly polarize the light emitted from the plurality of light sources before the light enters the plurality of hermetically isolated cells and
at least one heating element and at least one thermocouple, wherein the at least one heating element and the at least one thermocouple enable individual temperature regulation of individual cells in the plurality of hermetically isolated cells.

5. The wafer scale device of claim 2 , wherein the second substrate comprises:
a metalized reflector to reflect the light emitted from the at least one light source that passes through the plurality of hermetically isolated cells back into the plurality of hermetically isolated cells.

6. The wafer scale device of claim 2 , wherein the light source layer further comprises a plurality of photodetectors to detect light reflected from the plurality of hermetically isolated cells.

7. The wafer scale device of claim 2 , wherein the second substrate comprises at least one of:
a plurality of photodetectors to detect light emitted from the at least one light source that passes through the plurality of hermetically isolated cells; and
at least one temperature regulating device configured to enable individual temperature regulation of individual cells in the plurality of hermetically isolated cells.

8. The wafer scale device of claim 1 , wherein the first substrate, the cell layer, and the second substrate are joined together through at least one of:
thermocompression bonding;
oxide bonding;
thermosonic compression; and
solder bumps.

9. The wafer scale device of claim 1 , wherein the single measurement comprises an average of the separate measurements, wherein measurements in the separate measurements that are outliers are removed from the computation of the average.

10. The wafer scale device of claim 1 , wherein the wafer scale device is mounted within a hermetically sealed package.

11. The wafer scale device of claim 10 , wherein the hermetically sealed package is comprised of at least one of:
a low temperature co-fired ceramic;
an input/output pad for transmitting and receiving electrical communications;
a high permeability magnetic shield enclosure around the wafer scale device;
control circuitry configured to control the operation of the wafer scale device; and
at least one temperature regulating device configured to enable individual temperature regulation of individual cells in the plurality of hermetically isolated cells.

12. A wafer scale atomic clock, the atomic clock comprising:
an electronics layer;
a light source layer joined to the electronics layer, wherein electronics in the electronics layer control the emission of light from at least one light source in the light source layer;
a cell layer joined to the light source layer, the cell layer comprising a plurality of cells, wherein the at least one light source emits light into the separate cells in the plurality of cells; and
a light control layer joined to the cell layer opposite the light source layer, wherein light within the plurality of cells is incident on the light control layer and the light control layer comprises electronics.

13. The wafer scale atomic clock of claim 12 , wherein the cell layer comprises:
a first glass layer;
a wafer layer having the plurality of cells formed therein, wherein the plurality of cells extend from a first side of the wafer layer to an opposing second side of the wafer layer, wherein the first glass layer is bonded to a first side of the wafer layer, wherein matter is deposited in each cell in the plurality of cells; and
a second glass layer bonded to the opposing second side, wherein the separate cells in the plurality of cells are hermetically isolated.

14. The wafer scale atomic clock of claim 13 , wherein the first glass layer is anodically bonded to the wafer layer, and the second glass layer is anodically bonded to the wafer layer.

15. The wafer scale atomic clock of claim 12 , wherein the at least one light source acquires separate measurements from the separate cells, wherein the separate measurements are averaged together to provide a single measurement.

16. The wafer scale atomic clock of claim 12 , wherein the light control layer comprises a reflective surface that reflects light that passes through the plurality of cells back into the plurality of cells.

17. The wafer scale atomic clock of claim 12 , wherein the light source layer includes a plurality of photodetectors to detect the light that is reflected back towards the light source layer.

18. The wafer scale atomic clock of claim 12 , wherein the light control layer comprises a photodetector to detect light that passes through the plurality of cells.

19. A method for fabricating a wafer scale device, the method comprising:
fabricating a first substrate;
fabricating a cell layer, wherein the cell layer comprises a plurality of cells;
fabricating a second substrate;
joining the cell layer to the first substrate such that the first substrate is able to provide separate measurements for each cell in the plurality of cells; and
joining the second substrate to the cell layer opposite the first substrate, wherein the first substrate and the second substrate comprise electronics to control the separate measurements, wherein the separate measurements are averaged to form a single measurement.

20. The method of claim 19 , wherein fabricating the cell layer comprises:
forming a first glass layer;
forming a wafer layer, the wafer layer having the plurality of cells formed therein, wherein the plurality of cells extend from a first side of the wafer layer to an opposing second side of the wafer layer;
forming a second glass layer;
bonding the first glass layer to the first side of the wafer layer;
depositing matter in the plurality of cells; and

bonding the second glass layer to the opposing second side of the wafer layer.

Assignees

• Honeywell Int Inc

Inventors

• Kriz Jeffrey James
• Tucker James L
• Heffner Kenneth H
• Compton Robert

Classifications

• G04F5/14 Primary

  using atomic clocks · CPC title

• H03L7/26 Primary

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