Beam Steering Structure with Integrated Polarization Splitter

• US 20190384020A1
• Filed: 06/13/2019
• Published: 12/19/2019
• Est. Priority Date: 06/14/2018
• Status: Active Grant

• Current Assignee: Ayar Labs, Inc.
• Original Assignee: Ayar Labs, Inc.
• Inventors: Fini, John, Meade, Roy Edward, Van Orden, Derek, Wade, Mark
• Granted Patent: US 11,280,970 B2
• Time in Patent Office: Days
• CPC Class Codes: G02B 6/30 for use between fibre and thin-film device
• CPC Class Codes: G02B 6/3652 the additional structures being prepositioning mounting areas, allowing only movement in one dimension, e.g. grooves, trenches or vias in the microbench surface, i.e. self aligning supporting carriers
• CPC Class Codes: G02B 6/4206 Optical features G02B6/4207, G02B6/421 take precedence
• CPC Class Codes: G02B 6/4212 the intermediate optical element being a coupling medium interposed therebetween, e.g. epoxy resin, refractive index matching material, index grease, matching liquid or gel
• CPC Class Codes: G02B 6/4214 the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device G02B6/4246 takes precedence
• CPC Class Codes: G02B 6/423 using guiding surfaces for the alignment
• CPC Class Codes: G02B 6/4243 Mounting of the optical light guide into a groove mounting optical light guides into a groove in general G02B6/3636

Abstract

A beam steering structure includes an alignment structure shaped to receive and align an optical fiber such that an axis of a core of the optical fiber is oriented in a first direction. The beam steering structure includes an end portion having an angled optical surface oriented at a non-zero angle relative to the first direction. The end portion is shaped and positioned so that light propagating along the first direction from the optical fiber passes through the end portion to reach the angled optical surface. A reflecting system is positioned on the angled optical surface across the first direction. The reflecting system is configured to reflect incident light propagating along the first direction into a first reflected beam of a first polarization and a second reflected beam of a second polarization. The first and second reflected beams are directed into first and second optical communication channels, respectively.

Claims

1. A beam-turning assembly, comprising:

a beam steering structure including an alignment structure shaped to receive and align an optical fiber such that an axis of a core of the optical fiber is oriented in a first direction within the alignment structure, the beam steering structure including an end portion having an angled optical surface oriented at a non-zero angle relative to the first direction, the end portion shaped and positioned so that light propagating along the first direction from the optical fiber in the alignment structure passes through the end portion to reach the angled optical surface; and

a reflecting system positioned on the angled optical surface across the first direction so that light propagating along the first direction through the end portion is incident upon the reflecting system at the angled optical surface, the reflecting system configured to reflect incident light propagating along the first direction into a first reflected beam of a first polarization and a second reflected beam of a second polarization, the first reflected beam and the second reflected beam separated by a beam spacing sized to direct the first reflected beam into a first optical communication channel and to direct the second reflected beam into a second optical communication channel.

2. The beam-turning assembly as recited in claim 1, wherein the alignment structure is a v-groove structure.

3. The beam-turning assembly as recited in claim 1, wherein the alignment structure is formed integrally with the beam steering structure.

4. The beam-turning assembly as recited in claim 1, wherein the alignment structure is a v-groove array having multiple v-grooves oriented to extend parallel to each other, each v-groove of the multiple v-grooves configured to receive one optical fiber.

5. The beam-turning assembly as recited in claim 4, further comprising:

a fan-out device disposed between the v-groove array and the end portion of the beam steering structure, the fan-out device including separate optical waveguides for each v-groove in the v-groove array, wherein a spacing between adjacent ones of the optical waveguides at a location nearest to the reflecting system is smaller than a spacing between adjacent ones of the optical waveguides at a location nearest to the v-groove array.

6. The beam-turning assembly as recited in claim 5, wherein the optical waveguides of the fan-out device are part of a planar lightwave circuit or part of an interposer device.

7. The beam-turning assembly as recited in claim 5, wherein the beam steering structure, the reflecting system, and the fan-out device are included within an integrated optical interface device.

8. The beam-turning assembly as recited in claim 7, wherein the integrated optical interface device is one of a plurality of integrated optical interface devices fabricated in parallel on respective portions of a single substrate.

9. The beam-turning assembly as recited in claim 8, wherein the substrate is formed of silica or silicon.

10. The beam-turning assembly as recited in claim 1, wherein the beam steering structure includes a recessed region with the end portion positioned at an end of the recessed region, the alignment structure positioned in the recessed region.

11. The beam-turning assembly as recited in claim 1, wherein the beam spacing is sized to direct the first reflected beam into a first optical grating coupler of a photonic chip and to direct the second reflected beam into a second optical grating coupler of the photonic chip.

12. The beam-turning assembly as recited in claim 11, wherein the alignment structure is shaped to receive and align the optical fiber such that the first direction is substantially parallel to a surface of optical incidence of the photonic chip.

13. The beam-turning assembly as recited in claim 11, wherein the alignment structure is shaped to receive and align the optical fiber such that the first direction is not parallel to a surface of optical incidence of the photonic chip.

14. The beam-turning assembly as recited in claim 11, wherein a fill material is disposed between the beam turning assembly and the photonic chip, the fill material securing the beam turning assembly in a fixed spatial relationship with the photonic chip.

15. The beam-turning assembly as recited in claim 14, wherein the fill material has a material optical index value similar to a material optical index value of the beam steering structure.

16. The beam-turning assembly as recited in claim 1, further comprising:

an optical lensing element positioned between the optical fiber in the alignment structure and the end portion of the beam steering structure, the optical lensing element configured to direct convergence to a beam waist of the light propagating along the first direction through the end portion.

17. The beam-turning assembly as recited in claim 16, wherein the optical lensing element is connected to the optical fiber.

18. The beam-turning assembly as recited in claim 16, wherein the optical lensing element is connected to the beam steering structure.

19. The beam-turning assembly as recited in claim 16, wherein the optical lensing element is a GRIN lens or a graded-index optical fiber.

20. The beam-turning assembly as recited in claim 1, wherein the reflecting system is formed as a multilayer stack of materials including a first reflecting region, a second reflecting region, and a spacer region disposed between the first reflecting region and the second reflecting region.

21. The beam-turning assembly as recited in claim 20, wherein the first reflecting region is configured to reflect light of the first polarization and pass through light of the second polarization, and wherein the second reflecting region is configured to reflect light of the second polarization, and wherein the spacer region is substantially transparent to light that passes through the first reflecting region material.

22. The beam-turning assembly as recited in claim 21, wherein the first reflecting region includes one or more layers of a silicon oxynitride material.

23. A beam-turning assembly, comprising:

a beam steering structure including an alignment structure shaped to receive and align an optical fiber such that an axis of a core of the optical fiber is oriented in a first direction within the alignment structure, the beam steering structure including an end portion having an angled optical surface oriented at an angle relative to the first direction; and

a reflecting system positioned on the angled optical surface across the first direction so that light propagating along the first direction from the optical fiber is incident upon the reflecting system, the reflecting system configured to reflect incident light propagating along the first direction into a first reflected beam of a first polarization and a second reflected beam of a second polarization, the first reflected beam and the second reflected beam separated by a beam spacing sized to direct the first reflected beam into a first optical communication channel and to direct the second reflected beam into a second optical communication channel, wherein the end portion of the beam steering structure is shaped and positioned so that the first reflected beam and the second reflected beam do not pass through the beam steering structure.

24. A method for optical beam turning in an optical data communication system, comprising:

positioning an optical fiber in an alignment structure of a beam steering structure such that an axis of a core of the optical fiber is oriented in a first direction within the alignment structure, the first direction oriented toward a reflecting system positioned on an angled optical surface of an end portion of the beam steering structure, the angled optical surface oriented at a non-zero angle relative to the first direction, the reflecting system configured to reflect incident light propagating along the first direction into a first reflected beam of a first polarization and a second reflected beam of a second polarization, the first reflected beam and the second reflected beam separated by a beam spacing sized to direct the first reflected beam into a first optical communication channel and to direct the second reflected beam into a second optical communication channel; and

transmitting light through the optical fiber so that the light travels from the optical fiber in the first direction and is incident upon the reflecting system, the light incident upon the reflecting system being split into the first reflected beam and the second reflected beam.

25. The method as recited in claim 24, wherein the reflecting system is configured to set the beam spacing to a size that causes the first reflected beam to travel into a first optical grating coupler of a photonic chip and that causes the second reflected beam to travel into a second optical grating coupler of the photonic chip.

26. The method as recited in claim 25, wherein the alignment structure is shaped to receive and align the optical fiber such that the first direction is substantially parallel to a surface of optical incidence of the photonic chip.

27. The method as recited in claim 25, wherein the alignment structure is shaped to receive and align the optical fiber such that the first direction is not parallel to a surface of optical incidence of the photonic chip.

28. The method as recited in claim 25, further comprising:

disposing a fill material between the beam steering structure and the photonic chip such that the fill material secures the beam steering structure in a fixed spatial relationship with the photonic chip.

29. The method as recited in claim 24, further comprising:

positioning an optical lensing element between the optical fiber in the alignment structure and the end portion of the beam steering structure, the optical lensing element positioned and configured to direct convergence at a beam waist of the light propagating along the first direction through the end portion.

30. The method as recited in claim 24, wherein the reflecting system includes a first reflecting region that reflects light of the first polarization and passes through light of the second polarization, and wherein the reflecting system includes a second reflecting region that reflects light of the second polarization, and wherein the reflecting system includes a spacer region positioned between the first reflecting region and the second reflecting region, the spacer region being substantially transparent to light that passes through the first reflecting region.