Forming beamformer having stacked monolithic beamsplitters

• US 10,473,943 B1
• Filed: 11/08/2017
• Issued: 11/12/2019
• Est. Priority Date: 11/09/2016
• Status: Active Grant

• Current Assignee: ColdQuanta, Inc.
• Original Assignee: ColdQuanta, Inc.
• Inventors: Hughes, Steven Michael
• Primary Examiner(s): Chapel, Derek S.
• Application Number:
  US15/806,509
• Time in Patent Office: 734 Days
• Field of Search: None
• CPC Class Codes: G02B 1/11 Anti-reflection coatings
• CPC Class Codes: G02B 21/32 Micromanipulators structurally combined with microscopes
• CPC Class Codes: G02B 23/02 involving prisms or mirrors G02B23/14 takes precedence
• CPC Class Codes: G02B 27/0905 Dividing and/or superposing multiple light beams
• CPC Class Codes: G02B 27/0972 Prisms prisms per se G02B5/04
• CPC Class Codes: G02B 27/0977 Reflective elements
• CPC Class Codes: G02B 27/108 for sampling a portion of a beam or combining a small beam in a larger one, e.g. wherein the area ratio or power ratio of the divided beams significantly differs from unity, without spectral selectivity
• CPC Class Codes: G02B 27/142 Coating structures, e.g. thin films multilayers
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 7/021 for more than one lens
• CPC Class Codes: G21K 1/006 Manipulation of neutral particles by using radiation pressure, e.g. optical levitation production or acceleration of neutral particles H05H3/00

Abstract

Beamformers are formed (e.g., carved) from a stack of transparent sheets. A rear face of each sheet has a reflective coating. The reflectivities of the coatings vary monotonically with sheet position within the stack. The sheets are tilted relative to the intended direction of an input beam and then bonded to form the stack. The carving can include dicing the stack to yield stacklets, and polishing the stacklets to form beamformers. Each beamformer is thus a stack of beamsplitters, including a front beamsplitter in the form of a triangular or trapezoidal prism, and one or more beamsplitters in the form of rhomboid prisms. In use, a beamformer forms an output beam from an input beam. More specifically, the beamformer splits an input beam into plural output beam components that collectively constitute an output beam that differs in cross section from the input beam.

Claims

1. A beamformer assembly for forming beams of light, the beamformer assembly comprising plural beamformers, the plural beamformers including first and second beamformers, the second beamformer being optically coupled to the first beamformer so that a first beamformer, each of the first and second beamformers including:

a stack of prisms, each of the prisms being monolithic and having orthogonal faces and at least one oblique face oblique to the orthogonal faces, each prism being adjacent to at least one other prism in the stack; and

reflective layers, each reflective layer being disposed between oblique faces of adjacent prisms, each pair of adjacent prisms having a respective reflective layer disposed therebetween, the reflective layers having different reflectivities,

the reflective layers of the first beamformer being characterized by a first beamsplitting angle, the reflective layers of the second beamformer being characterized by a second beamsplitting angle different from the first beamsplitting angle;

the first beamformer outputting a second portion of the light input to the first beamformer in a first direction that is, at least in part, a function of the first beamsplitting angle, the second beamformer outputting light received from the first beamformer in a second direction that is different from the first direction and, at least in part, is based on the second beamsplitting angle.

2. The beamformer of claim 1 wherein at least one of the prisms is a rhomboid prism and at least one of the prisms is a triangular or trapezoidal prism.

3. The beamformer of claim 1 wherein the prisms include plural rhomboid prisms and at least one of the prisms is a triangular or trapezoidal prism.

4. The beamformer of claim 1 wherein each prism has a non-oblique face with an anti-reflection coating thereon.

5. The beamformer of claim 4 wherein each prism has a non-oblique face without an anti-reflection coating thereon.

6. The beamformer assembly of claim 1 wherein the second portion output by the first beamformer and the light output by the second beamformer intersect.

7. The beamformer assembly of claim 6 wherein the plural beamformers includes a third beamformer, the third beamformer being characterized by a third beamsplitting angle different from the first beamsplitting angle and different from the second beamsplitting angle, the third beamformer being arranged relative to the first and second beamformers such that light output from the third beamformer intersects the second portion output by the first beamformer and the light output by the second beamformer.

8. The beamformer assembly of claim 7 wherein the first and second directions are orthogonal to each other, and wherein light is output from the third beamformer in a third direction that is orthogonal to the first direction and to the second direction.

9. The beamformer assembly of claim 7 wherein the second portion output by the first beamformer, the light output by the second beamformer, and the light output by the third beamformer cooperate to define an optical trap.

10. A process for forming a beamformer assembly, the process comprising:

forming plural beamformers including a first beamformer and a second beamformer, each beamformer being formed by,

forming a stack of transparent sheets having reflective coatings, each transparent sheet being bonded to at least one other transparent sheet, the reflective coatings having different reflectivities; and

carving the stack to define an array of prisms, each prism having been carved from a respective one of the transparent sheets, each of the prisms being monolithic and having at least one oblique face, each prism being bonded to at least one other prism in the array, each beamformer being characterized by a respective beamsplitting angle so that the first beamsplitter is characterized by a first beamsplitting angle, and the second beamsplitter is characterized by a second beamsplitting angle, different from the first beamsplitting angle; and

optically coupling the second beamformer to the first beamformer so that a first portion of light input to the first beamformer is transferred to the second beamformer, the first beamformer outputting a second portion of the light input to the first beamformer in a first direction that is, at least in part, a function of the first beamsplitting angle, the second beamformer outputting light received from the first beamformer in a second direction that is different from the first direction and, at least in part, is based on the second beamsplitting angle.

11. The process of claim 10 wherein the carving includes polishing to form flat faces of the prisms.

12. The process of claim 11 wherein the carving also involves dicing the stack prior to the polishing to form plural stacklets, the polishing converting the stacklets to prisms.

13. The process of claim 10 wherein at least one of the prisms is a rhomboid prism and at least one of the prisms is a triangular or trapezoidal prism.

14. The process of claim 10 wherein the prisms include plural rhomboid prisms and at least one of the prisms is a triangular or trapezoidal prism.

15. The process of claim 10 further comprising applying anti-reflection coatings to at least one non-oblique face of each of the prisms.

16. The process of claim 15 further comprising applying anti-reflection coatings to exactly one face of each of the prisms.

17. The process of claim 10 wherein the second portion output by the first beamformer and the light output by the second beamformer intersect.

18. The process of claim 17 wherein the plural beamformers includes a third beamformer, the third beamformer being characterized by a third beamsplitting angle different from the first beamsplitting angle and different from the second beamsplitting angle, the third beamformer being arranged relative to the first and second beamformers such that light output from the third beamformer intersects the second portion output by the first beamformer and the light output by the second beamformer.

19. The process of claim 18 wherein the first and second directions are orthogonal to each other, and wherein light is output from the third beamformer in a third direction that is orthogonal to the first direction and to the second direction.

20. The process of claim 18 wherein the second portion output by the first beamformer, the light output by the second beamformer, and the light output by the third beamformer cooperate to define an optical trap.