Directly written waveguide for coupling of laser to photonic integrated circuit

Patent metadata

Field	Value
Publication number	US-10670818-B2
Application number	US-201816231284-A
Country	US
Kind code	B2
Filing date	Dec 21, 2018
Priority date	Dec 21, 2017
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

Systems, devices, and methods of manufacturing optical engines and laser projectors that are well-suited for use in wearable heads-up displays (WHUDs) are described. Generally, the optical engines of the present disclosure integrate a plurality of laser diodes (e.g., 3 laser diodes, 4 laser diodes) within a single, hermetically or partially hermetically sealed, encapsulated package. Photonic integrated circuits having grating or edge couplers thereon may be used to wavelength multiplex beams of light emitted by the plurality of laser diodes into a coaxially superimposed aggregate beam. A waveguide medium having one or more directly written waveguides may couple light from laser diodes to a photonic integrated circuit, and may optionally hermetically or partially hermetically seal the laser diodes, eliminating the need for a separate seal. Such optical engines may have advantages over existing designs including, for example, smaller volumes, better manufacturability, faster modulation speed, etc. WHUDs that employ such optical engines and laser projectors are also described.

First claim

The invention claimed is:

1. A wearable heads-up display (WHUD), comprising:
a support structure that in use is worn on the head of a user;
a laser projector carried by the support structure, the laser projector comprising:
an optical engine, comprising:
a base substrate;
a plurality of laser diodes, each of the plurality of laser diodes bonded directly or indirectly to the base substrate;
at least one laser diode driver circuit operatively coupled to the plurality of laser diodes to selectively drive current to the plurality of laser diodes;
a photonic integrated circuit bonded to the base substrate at a position that is spaced apart from the plurality of laser diodes, the photonic integrated circuit comprising a plurality of input facets and at least one output facet, in operation, the photonic integrated circuit receives a plurality of beams of light at the respective plurality of input facets and wavelength multiplexes the plurality of beams of light to provide an aggregated beam of light at the output facet; and
a waveguide and sealing medium that covers and hermetically or partially hermetically seals the plurality of laser diodes, the waveguide and sealing medium comprising at least one directly written waveguide that couples the plurality of beams of light emitted by the plurality of laser diodes to the input facets of the photonic integrated circuit; and

at least one scan mirror positioned to receive the aggregate beam of light output at the output facet of the photonic integrated circuit, the at least one scan mirror controllably orientable to redirect the aggregate beam of light over a range of angles.

2. The WHUD of claim 1 , further comprising:
a transparent combiner carried by the support structure and positioned within a field of view of the user, in operation the transparent combiner directs laser light from an output of the laser projector into the field of view of the user.

3. The WHUD of 1 wherein each of the plurality of input facets of the photonic integrated circuit comprises a grating input coupler or an edge input coupler.

4. The WHUD of claim 1 , further comprising:
a collimation lens positioned and oriented to receive and collimate the aggregate beam of light from the output facet of the photonic integrated circuit.

5. The WHUD of claim 1 , further comprising at least one diffractive optical element positioned and oriented to receive the aggregate beam of light, in operation, the at least one diffractive optical element provides wavelength dependent focus correction for the aggregate beam of light.

6. The WHUD of claim 1 wherein the at least one laser diode driver circuit is bonded to a first surface of the base substrate, and the plurality of laser diodes and the waveguide and sealing medium are bonded to a second surface of the base substrate, the second surface of the base substrate opposite the first surface of the base substrate.

7. The WHUD of claim 1 wherein the at least one laser diode driver circuit, the plurality of laser diodes, and the waveguide and sealing medium are bonded to a first surface of the base substrate.

8. The WHUD of claim 1 wherein the plurality of laser diodes and the waveguide and sealing medium are bonded to the base substrate, and the at least one laser diode driver circuit is bonded to another substrate separate from the base substrate.

9. The WHUD of claim 1 wherein the photonic integrated circuit includes a first plurality of waveguides, each waveguide of the first plurality of waveguides having a respective input facet, and the waveguide medium includes a second plurality of waveguides, each waveguide of the second plurality of waveguides to receive laser light from a respective laser diode of the plurality of laser diodes and couple the received laser light to the input facet of a respective waveguide in the first plurality of waveguides.

10. An optical engine, comprising:
a base substrate;
a plurality of laser diodes, each of the plurality of laser diodes bonded directly or indirectly to the base substrate;
at least one laser diode driver circuit operatively coupled to the plurality of laser diodes to selectively drive current to the plurality of laser diodes;
a photonic integrated circuit bonded to the base substrate at a position that is spaced apart from the plurality of laser diodes, the photonic integrated circuit comprising a plurality of input facets and at least one output facet, in operation, the photonic integrated circuit receives a plurality of beams of light at the respective plurality of input facets and wavelength multiplexes the plurality of beams of light to provide an aggregated beam of light at the output facet; and
a waveguide and sealing medium that covers and hermetically or partially hermetically seals the plurality of laser diodes, the waveguide and sealing medium comprising at least one directly written waveguide that couples the plurality of beams of light emitted by the plurality of laser diodes to the input facets of the photonic integrated circuit.

11. The optical engine of claim 10 wherein the waveguide and sealing medium comprises an organically modified ceramic (ORMOCER) material.

12. The optical engine of claim 10 wherein each of the plurality of input facets of the photonic integrated circuit comprises one of a grating input coupler or an edge input coupler.

13. The optical engine of claim 10 , further comprising:
a collimation lens positioned and oriented to receive and collimate the aggregate beam of light from the output facet of the photonic integrated circuit.

14. The optical engine of claim 13 wherein the collimation lens comprises one of an achromatic lens or an apochromatic lens.

15. The optical engine of claim 10 , further comprising at least one diffractive optical element positioned and oriented to receive the aggregate beam of light, in operation, the at least one diffractive optical element provides wavelength dependent focus correction for the aggregate beam of light.

16. The optical engine of claim 10 , further comprising:
a plurality of chip submounts bonded to the base substrate, wherein each of the laser diodes are bonded to a corresponding one of the plurality of chip submounts.

17. The optical engine of claim 10 wherein the plurality of laser diodes includes a red laser diode to provide a red laser light, a green laser diode to provide a green laser light, a blue laser diode to provide a blue laser light, and an infrared laser diode to provide infrared laser light.

18. The optical engine of claim 10 wherein the at least one laser diode driver circuit is bonded to a first surface of the base substrate, and the plurality of laser diodes and the cap are bonded to a second surface of the base substrate, the second surface of the base substrate opposite the first surface of the base substrate.

19. The optical engine of claim 10 wherein the at least one laser diode driver circuit, the plurality of laser diodes, and the cap are bonded to a first surface of the base substrate.

20. The optical engine of claim 10 wherein the photonic integrated circuit includes a first plurality of waveguides, each waveguide of the first plurality of waveguides having a respective input facet, and the waveguide medium includes a second plurality of waveguides, each waveguide of the second plurality of waveguides to receive laser light from a respective laser diode of the plurality of laser diodes and couple the received laser light to the input facet of a respective waveguide in the first plurality of

Assignees

• North Inc

Inventors

• Pierer Jörg
• James Rony Jose
• Mohrdiek Stefan
• Kiik Martin Joseph
• Haque Syed Moez
• Dykaar Douglas Raymond

Classifications

• G02B6/12004

  Combinations of two or more optical elements · CPC title

• H01S5/02296

  Electricity · mapped topic

• G02B6/13

  Integrated optical circuits characterised by the manufacturing method · CPC title

• H01S5/423

  having a vertical cavity · CPC title

• G02B6/12007

  forming wavelength selective elements, e.g. multiplexer, demultiplexer · CPC title