High speed free-space optical communications

• US 10,615,871 B2
• Filed: 11/19/2015
• Issued: 04/07/2020
• Est. Priority Date: 02/17/2009
• Status: Active Grant

• Current Assignee: Lumentum Operations, LLC (Lumentum Holdings Inc.)
• Original Assignee: TriLumina Corp
• Inventors: Joseph, John R., Lear, Kevin L., Abell, David
• Primary Examiner(s): Lambert, David W
• Application Number:
  US14/946,730
• Publication Number:
  US 20160080077A1
• Time in Patent Office: 1,601 Days
• Field of Search: None
• CPC Class Codes: G02B 27/0905 Dividing and/or superposing multiple light beams
• CPC Class Codes: G02B 27/0944 Diffractive optical elements, e.g. gratings, holograms gratings per se G02B5/18; holograms used as optical elements per se G02B5/32
• CPC Class Codes: G02B 27/10 Beam splitting or combining systems polarising systems G02B27/28; mixing and splitting light signals using optical waveguides G02B6/28; beam shaping, e.g. changing the cross-sectional area, by dividing or superposing multiple light beams G02B27/0905
• CPC Class Codes: G02B 5/02 Diffusing elements; Afocal elements
• CPC Class Codes: G02B 5/32 Holograms used as optical elements
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/02325 Mechanically integrated components on mount members or optical micro-benches
• CPC Class Codes: H01S 5/02345 Wire-bonding
• CPC Class Codes: H01S 5/06226 Modulation at ultra-high frequencies
• CPC Class Codes: H01S 5/423 having a vertical cavity
• CPC Class Codes: H01S 5/50 Amplifier structures not provided for in groups H01S5/02 - H01S5/30
• CPC Class Codes: H04B 10/11 Arrangements specific to free-space transmission, i.e. transmission through air or vacuum
• CPC Class Codes: H04B 10/503 Laser transmitters

Abstract

High power, high speed VCSEL arrays are employed in unique configurations of arrays and sub-arrays. Placement of a VCSEL array behind a lens allows spatial separation and directivity. Diffusion may be employed to increase alignment tolerance. Intensity modulation may be performed by operating groups of VCSEL emitters at maximum bias. Optical communications networks with high bandwidth may employ angular, spatial, and/or wavelength multiplexing. A variety of network topologies and bandwidths suitable for the data center may be implemented. Eye safe networks may employ VCSEL emitters may be paired with optical elements to reduce optical power density to eye safe levels.

Claims

1. A multi-channel optical communications device for free-space optical communications capable of non-mechanical beam directivity, the device comprising at least two symmetric, oppositely facing transceiver systems, each comprising:

a transmitting lens;

an optical diffuser positioned behind the lens at a distance equal to a focal length of the lens;

a plurality of laser emitter clusters positioned behind the optical diffuser, each of the plurality of laser emitter clusters configured to emit a laser beam bundle, each laser emitter cluster positioned relative to the transmitting lens so the emitted laser beam bundle travels a distinct optical path through the optical diffuser and the transmitting lens, wherein the optical path is separated and angularly-shifted from optical paths of other laser beam bundles; and

circuitry configured to activate one of the plurality of laser emitter clusters based on a desired optical path for the laser beam.

2. The device of claim 1, wherein the plurality of laser emitter clusters are configured in a linear array.

3. The device of claim 1, wherein the plurality of laser emitter clusters are configured in a two-dimensional array.

4. The device of claim 1, wherein the optical diffuser is a holographic diffuser.

5. The device of claim 1, wherein the optical diffuser is configured to distort the laser beam bundles to produce lines or other geometric figures at fixed angular distances from each other.

6. The device of claim 1, wherein a first laser emitter cluster forms a laser beam bundle having a first geometrical pattern, and a second laser emitter cluster forms a laser beam bundle having a second geometrical pattern, wherein the first geometrical pattern and the second geometrical pattern are angularly separated.

16. The device of claim 1, wherein each transceiver system further comprises two or more receiver lenses and corresponding detector/amplifier pair elements.

17. The device of claim 16, wherein the plurality of laser emitter clusters and the detector/amplifier pair elements have a shared substrate.

18. The device of claim 17, wherein each of the two or more receiver lenses and corresponding detector/amplifier pair elements are positioned at a periphery of the shared substrate and the transmitting lens, the optical diffuser and the plurality of laser emitter clusters are positioned towards a center of the shared substrate.

7. A multi-channel optical illumination device for optical sensing with an imaging array or detector array capable of non-mechanical beam directivity, the device comprising at least two symmetric, oppositely facing transceiver systems, each comprising:

a transmitting lens;

an optical diffuser positioned behind the lens at a distance equal to a focal length of the lens;

a plurality of laser emitter clusters positioned behind the optical diffuser, wherein one or more laser emitter clusters among the plurality of laser emitter clusters are each configured to emit a laser beam bundle each laser emitter cluster positioned relative to the transmitting lens so the emitted laser beam bundle travels a distinct optical path through the optical diffuser and the lens, wherein the optical path is separated and angularly-shifted from optical paths of other laser beam bundles; and

circuitry configured to activate one or more of the plurality of laser emitter clusters based on one or more desired optical paths for the laser beams.

8. The device of claim 7, wherein the plurality of laser emitter clusters are configured in a linear array.

9. The device of claim 7, wherein the plurality of laser emitter clusters are configured in a two-dimensional array.

10. The device of claim 7, wherein the optical diffuser is a holographic diffuser.

11. The device of claim 7, wherein the optical diffuser is configured to distort the laser beam bundles to produce lines or other geometric figures at fixed angular distances from each other.

12. The device of claim 7, wherein a first laser emitter cluster forms a laser beam bundle having a first geometrical pattern, and a second laser emitter cluster forms a laser beam bundle having a second geometrical pattern, wherein the first geometrical pattern and the second geometrical pattern are angularly separated.

13. A multi-channel optical illumination device for optical sensing with an imaging array or detector array capable of non-mechanical beam directivity, the device comprising at least two symmetric, oppositely facing transceiver systems, each comprising:

a transmitting lens;

an optical diffuser positioned behind the lens at a distance equal to a focal length of the lens;

a plurality of laser emitters positioned behind the optical diffuser, wherein the plurality of laser emitters are configured in groups sufficient to enable a group to emit laser beams, each group positioned relative to the transmitting lens so the emitted laser beams each travel a distinct optical path through the optical diffuser and the lens and produce illumination beam bundles distinct from laser beam bundles emitted by any other group, wherein each illumination beam bundle is separated and angularly-shifted from other illumination beam bundles; and

circuitry configured to activate one of the groups based on a desired optical path for the laser beam of the group.

14. The device of claim 13, wherein the optical diffuser is a holographic diffuser configured to distort the laser beams of the groups to produce lines or other geometric figures at fixed angular distances from each other.

15. The device of claim 13, wherein a first set of laser emitters among the plurality of laser emitters are grouped so the laser beams of a first group form a first geometrical pattern and a second set of laser emitters among the plurality of laser emitters are grouped so the laser beams of a second group form a second geometrical pattern, the first geometrical pattern being angularly separated from the second geometrical pattern.