Scanning laser projector

• US 9,426,435 B2
• Filed: 03/09/2015
• Issued: 08/23/2016
• Est. Priority Date: 08/12/2010
• Status: Active Grant

• Current Assignee: OctroliX B.V.
• Original Assignee: OctroliX B.V.
• Inventors: Dekker, Ronald, Klein, Edwin Jan
• Primary Examiner(s): Lepisto, Ryan
• Assistant Examiner(s): El Shammaa, Mary A
• Application Number:
  US14/641,641
• Publication Number:
  US 20150189245A1
• Time in Patent Office: 533 Days
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0062 Arrangements for scanning
• CPC Class Codes: A61B 5/0064 Body surface scanning
• CPC Class Codes: A61B 5/0068 Confocal scanning
• CPC Class Codes: A61B 5/4887 Locating particular structures in or on the body
• CPC Class Codes: A61B 5/489 Blood vessels
• CPC Class Codes: G02B 2006/12035 Materials
• CPC Class Codes: G02B 6/12004 Combinations of two or more optical elements
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/29388 for lighting or use with non-coherent light
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 33/06 by additive-colour projection apparatus
• CPC Class Codes: G03B 33/12 using beam-splitting or beam-combining systems, e.g. dichroic mirrors
• CPC Class Codes: H04N 9/3129 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

Abstract

A scanning projector suitable for projecting an image comprising a plurality of wavelength signals (i.e., light signals having different wavelengths) is disclosed. Embodiments of the present invention comprise a beam combiner comprising a planar lightwave circuit that includes a plurality of surface waveguides arranged in define a plurality of input ports, a mixing region, and an output port. Different wavelength signals received at the input ports are combined into a composite output beam that is scanned over a region. The projector (1) scans a first wavelength signal over a plurality of image points in the region, (2) detects an amount of the first wavelength signal reflected from each image point, whose reflectivity at the first wavelength is based on a measurand, and (3) projects an image onto the region using a second wavelength signal, where the image is based on the reflected first wavelength signal at each of the image points.

Claims

1. A scanning projector comprising:

a first light source that provides a first light signal characterized by a first wavelength;

a second light source that provides a second light signal characterized by a second wavelength;

a beam combiner comprising a planar lightwave circuit including plurality of waveguides that are arranged to define a first input port, a second input port, a mixing region, and an output port, the beam combiner;

(1) receiving the first light signal at the first input port, (2) receiving the second light signal at the second input port, (3) combining the first light signal and the second light signal into a composite output signal, and (4) providing the composite output signal at the output port; and

a scanner, the scanner receiving the composite output signal from the beam combiner and scanning the composite output signal over each of a plurality of image points in a first region.

2. The projector of claim 1 wherein the planar lightwave circuit comprises a first waveguide having an inner core comprising silicon dioxide and an outer core comprising silicon nitride.

3. The projector of claim 1 wherein the planar lightwave circuit comprises a first waveguide having a core comprising silicon nitride.

4. The projector of claim 1 wherein the planar lightwave circuit comprises a first waveguide comprising:

a first layer comprising silicon nitride; and

a second layer comprising silicon dioxide, the second layer disposed on and in contact with the first layer, and the second layer being a TEOS-based layer.

5. The projector of claim 1 further comprising a photodetector, the photodetector being dimensioned and arranged to receive a reflected light signal from each of the plurality of image points and generate a first electrical signal based on a characteristic of the received light signal;

and

a processor that controls the second light source based on the first electrical signal.

6. The projector of claim 5 wherein the characteristic is intensity.

7. The projector of claim 5 wherein the characteristic is polarization mode.

8. The projector of claim 5 wherein the characteristic is wavelength.

9. The projector of claim 1 further comprising:

a third light source that provides a third light signal characterized by a third wavelength; and

a third input port, wherein the plurality of waveguides are arranged to further define the third input port, the beam combiner receiving the third light signal at the third input port and combining the third light signal into the composite output signal.

10. The projector of claim 9 wherein the first wavelength, second wavelength, and third wavelength are irregularly spaced.

11. The projector of claim 1 wherein the mixing region comprises a plurality of directional couplers that is arranged in a first arrangement comprising a tree structure.

12. The projector of claim 1 wherein the first input port includes a mode-matching region comprising (1) a first facet that is substantially mode-matched to an output facet of the first light source and (2) an interface that is optically coupled with a first waveguide of the plurality of waveguides, and wherein the input port is optically coupled with each of the first light source and the first waveguide.

13. The projector of claim 1 wherein the planar lightwave circuit further comprises a first attenuator, the first attenuator being dimensioned and arranged to control the optical power of the first light signal in the composite output signal.

14. A scanning projector comprising:

a plurality of light sources, wherein each of the plurality of light sources provides a different one of a plurality of light signals, each of the plurality of light signals being characterized by a different wavelength, and wherein the plurality of wavelengths are irregularly spaced;

a beam combiner comprising a planar lightwave circuit that includes a plurality of input ports, a mixing region, and an output port, wherein each of the plurality of input ports receives a different one of the plurality of light signals, and wherein the mixing region combines the plurality of light signals into a composite output signal that is provided at the output port; and

a scanner, the scanner receiving the composite output signal from the beam combiner and scanning the composite output signal over each of a plurality of image points in a first region.

15. The projector of claim 14 wherein the mixing region comprises a plurality of directional couplers that are arranged in a tree structure.

16. The projector of claim 14 wherein the planar lightwave circuit comprises a first waveguide having a core comprising stoichiometric silicon nitride and a cladding layer comprising silicon dioxide.

17. The projector of claim 16 wherein the plurality of input ports comprises a first input port that includes (1) an end facet that is optically coupled with a first light source of the plurality of light sources and (2) an interface that is optically coupled with the first waveguide, and wherein the end facet is characterized by a first optical mode that substantially matches the output optical mode of the first light source, and further wherein the interface is characterized by a second optical mode that substantially matches the optical mode of the first waveguide.

18. The projector of claim 14 further comprising a photodetector, the photodetector being dimensioned and arranged to receive a reflected light signal from each of the plurality of image points and generate a first electrical signal based on a characteristic of the received light signal;

and

a processor that controls the second light source based on the first electrical signal.

19. The projector of claim 18 wherein the characteristic is intensity.

20. The projector of claim 18 wherein the characteristic is polarization mode.

21. The projector of claim 18 wherein the characteristic is wavelength.

22. The projector of claim 14 wherein the planar lightwave circuit further comprises a first attenuator, the first attenuator being dimensioned and arranged to control the optical power of a first light signal of the plurality of light signals in the composite output signal.

23. A method comprising:

receiving a first light signal characterized by a first wavelength at a first input port of a beam combiner, wherein the beam combiner comprises a planar lightwave circuit that includes the first input port and a second input port, a mixing region, and an output port;

receiving a second light signal characterized by a second wavelength at the second input port;

combining the first light signal and the second light signal in a composite output signal that is provided at the output port; and

scanning the composite output signal over a first region.

24. The method of claim 23 further comprising providing the beam combiner such that the first input port includes a mode-matching region, the mode-matching region having (1) an end facet characterized by a first optical mode that substantially matches the output optical mode at an output facet of a first light source that provides the first light signal and (2) an interface characterized by a second optical mode that substantially matches the optical mode of a first waveguide, the planar lightwave circuit comprising the first waveguide.

25. The method of claim 23 further comprising:

providing the beam combiner such that the planar lightwave circuit includes an attenuator; and

controlling the attenuator to control the output power of the first light signal in the composite output signal.

26. The method of claim 23 further comprising:

directing the composite output signal at a first image point in the first region;

generating a first electrical signal that is based on a first reflected light signal reflected from the first image point, wherein a first characteristic of the first reflected light signal is based on a first property of the first image point; and

controlling the second light signal based on the first characteristic.

27. The method of claim 26 wherein the second light signal is controlled such that the second light signal has a first magnitude when the first characteristic has a first value and a second magnitude when the first characteristic has a second value that is different than the first value.

28. The method of claim 26 further comprising:

directing the composite output signal at a second image point in the first region;

generating a second electrical signal that is based on a second reflected light signal reflected from the second image point, wherein a second characteristic of the second reflected light signal is based on a second property of the second image point; and

controlling the second light signal based on the second characteristic.