Free space multiple laser diode modules

Patent metadata

Field	Value
Publication number	US-11454817-B2
Application number	US-202117143898-A
Country	US
Kind code	B2
Filing date	Jan 7, 2021
Priority date	Oct 23, 2017
Publication date	Sep 27, 2022
Grant date	Sep 27, 2022

Abstract

Systems, devices, and methods for 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 sealed, encapsulated package. Such optical engines may have various 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 method of operating an optical engine, the optical engine comprising a plurality of laser diodes sealed in an encapsulated package, the method comprising:
causing the plurality of laser diodes to generate laser light, comprising:
receiving the laser light from each of the laser diodes of the plurality of laser diodes by a single face of an optical director element shared between the plurality of laser diodes;
redirecting, by the single face of the optical director element, the received laser light toward an optical window of the encapsulated package; and
collimating, by a plurality of collimation lenses, the laser light from the plurality of laser diodes that exits the encapsulated package via the optical window to generate a plurality of laser light beams.

2. The method of claim 1 , further comprising:
combining, via a beam combiner, the plurality of laser light beams received from the plurality of collimation lenses into a single aggregate beam; and
routing the single aggregate beam to a controllable scan mirror.

3. The method of claim 2 , wherein combining the plurality of laser light beams comprises:
receiving, by a first optical element of the beam combiner, a first laser light generated by a first laser diode of the plurality of laser diodes; and
redirecting, by the first optical element, the first laser light to travel in a first direction.

4. The method of claim 3 , wherein combining the plurality of laser light beams further comprises:
receiving, by a second optical element of the beam combiner, the first laser light travelling in the first direction and a second laser light generated by a second laser diode of the plurality of laser diodes;
transmitting, by the second optical element, the first laser light travelling in the first direction; and
redirecting, by the second optical element, the second laser light to travel in the first direction.

5. The method of claim 4 , wherein combining the plurality of laser light beams further comprises:
receiving, by a third optical element of the beam combiner, the first laser light traveling in the first direction, the second laser light traveling in the first direction, and a third laser light generated by a third laser diode of the plurality of laser diodes;
transmitting, by the third optical element, the first laser light traveling in the first direction and the second laser light traveling in the first direction; and
redirecting, by the third optical element, the third laser light to travel in the first direction.

6. The method of claim 5 , wherein combining the plurality of laser light beams further comprises:
receiving, by a fourth optical element of the beam combiner, at least the first laser light, the second laser light, and the third laser light; and
routing, by the fourth optical element, at least the first laser light, the second laser light, and the third laser light to a controllable scan mirror.

7. The method of claim 6 , further comprising:
receiving, by the controllable scan mirror, an aggregate beam comprising at least the first laser light, the second laser light, and the third laser light; and
scanning, by the controllable scan mirror, the aggregate beam to an eye of a user.

8. The method of claim 1 , wherein causing the plurality of laser diodes to generate laser light further comprises:
causing a first laser diode of the plurality of laser diodes to generate a first laser light;
causing a second laser diode of the plurality of laser diodes to generate a second laser light; and
causing a third laser diode of the plurality of laser diodes to generate a third laser light.

9. The method of claim 8 , wherein:
causing the first laser diode to generate first laser light comprises causing the first laser diode to generate the first laser light as red laser light;
causing the second laser diode to generate the second laser light comprises causing the second laser diode to generate the second laser light as green laser light; and
causing the third laser diode to generate the third laser light comprises causing the third laser diode to generate the third laser light as blue laser light.

10. An optical engine, comprising:
a plurality of laser diodes sealed in an encapsulated package, wherein each laser diode of the plurality of laser diodes is configured to generate laser light;
an optical director element configured to receive the laser light from each of the laser diodes of the plurality of laser diodes by a single face of the optical director element shared between the plurality of laser diodes, wherein the single face of the optical director element is configured to redirect the received laser light toward an optical window of the encapsulated package; and
a plurality of collimation lenses configured to collimate the laser light from the plurality of laser diodes that exits the encapsulated package via the optical window to generate a plurality of laser light beams.

11. The optical engine of claim 10 , further comprising:
a beam combiner configured to combine the plurality of laser light beams received from the plurality of collimation lenses into a single aggregate beam.

12. The optical engine of claim 11 , wherein the beam combiner comprises a first optical element configured to:
receive a first laser light generated by a first laser diode of the plurality of laser diodes; and
redirect the first laser light to travel in a first direction.

13. The optical engine of claim 12 , wherein the beam combiner comprises a second optical element configured to:
receive the first laser light travelling in the first direction and a second laser light generated by a second laser diode of the plurality of laser diodes;
transmit, the first laser light travelling in the first direction; and
redirect the second laser light to travel in the first direction.

14. The optical engine of claim 13 , wherein the beam combiner comprises a third optical element configured to:
receive the first laser light traveling in the first direction, the second laser light traveling in the first direction, and a third laser light generated by a third laser diode of the plurality of laser diodes;
transmit the first laser light traveling in the first direction and the second laser light traveling in the first direction; and
redirect the third laser light to travel in the first direction.

15. The optical engine of claim 14 , wherein the beam combiner comprises:
a fourth optical element configured to receive at least the first laser light, the second laser light, and the third laser light, and route at least the first laser light, the second laser light, and the third laser light to a controllable scan mirror.

16. The optical engine of claim 15 , wherein the controllable scan mirror is configured to:
receive an aggregate beam comprising at least the first laser light, the second laser light, and the third laser light; and
scan the aggregate beam to an eye of a user.

17. The optical engine of claim 10 , wherein:
a first laser diode of the plurality of laser diodes is configured to generate a first laser light;
a second laser diode of the plurality of laser diodes is configured to generate a second laser light; and
a third laser diode of the plurality of laser diodes is configured to generate a third laser light.

18. The optical engine of claim 17 , wherein:
the first laser diode is further configured to generate the first laser light as red laser light;
the second laser diode is further configured to generate the second laser light

Assignees

• Google Llc

Inventors

• Pierer Jorg
• James Rony Jose
• Mohrdiek Stefan
• Dykaar Douglas Raymond

Classifications

• H01S5/02325

  Mechanically integrated components on mount members or optical micro-benches · CPC title

• H04N9/3161

  using laser light sources (using laser beams scanning the display screen H04N9/3129) · CPC title

• G02B26/101

  with both horizontal and vertical deflecting means, e.g. raster or XY scanners (colour television using laser beams scanning a display screen H04N9/3129) · CPC title

• H01S5/4012

  Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms · CPC title

• H04N9/3129 Primary

  scanning a light beam on the display screen (scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161) · CPC title