Illumination module

• US 7,423,802 B2
• Filed: 08/29/2007
• Issued: 09/09/2008
• Est. Priority Date: 06/01/2005
• Status: Expired due to Fees

• Current Assignee: Collinear Corp.
• Original Assignee: Collinear Corp.
• Inventors: Miller, Gregory D.
• Primary Examiner(s): Sanghavi; Hemang
• Application Number:
  US11/897,530
• Publication Number:
  US 20080055714A1
• Time in Patent Office: 377 Days
• Field of Search: 359326-330, 385/14, 385/37
• US Class Current: 359/326
• CPC Class Codes: G02B 6/12019 characterised by the optical interconnection to or from the AWG devices, e.g. integration or coupling with lasers or photodiodes coupling integrated waveguide to fibre G02B6/30, to optoelectronic element G02B6/42; monolithic integration of integrated waveguides with other optical elements G02B6/12004
• CPC Class Codes: G02F 1/3532 Arrangements of plural nonlinear devices for generating multi-colour light beams, e.g. arrangements of SHG, SFG, OPO devices for generating RGB light beams
• CPC Class Codes: G02F 1/37 for second-harmonic generation G02F1/3532 takes precedence
• CPC Class Codes: G02F 1/39 for parametric generation or amplification of light, infrared or ultraviolet waves
• CPC Class Codes: H04N 9/3158 for controlling the spectrum
• CPC Class Codes: H04N 9/3161 using laser light sources using laser beams scanning the display screen H04N9/3129

Abstract

An illumination module may provide light in a plurality of colors including Red-Green-Blue (RGB) light and/or white light. The light from the illumination module may be directed to a 3LCD system, a Digital Light Processing (DLP®) system, a Liquid Crystal on Silicon (LCoS) system, or other micro-display or micro-projection systems. In one embodiment the illumination module includes a laser configured to produce an optical beam at a first wavelength, a planar lightwave circuit coupled to the laser and configured to guide the optical beam, and a waveguide optical frequency converter coupled to the planar lightwave circuit and configured to receive the optical beam at the first wavelength, convert the optical beam at the first wavelength into an output optical beam at a second wavelength, and may provide optically coupled feedback which is nonlinearly dependent on a power of the optical beam at the first wavelength to the laser.

Claims

1. A system comprising:

a laser configured to produce an optical beam at a first wavelength;

a planar lightwave circuit coupled to the laser and configured to guide the optical beam; and

a waveguide optical frequency converter coupled to the planar lightwave circuit, and configured to receive the optical beam at the first wavelength, convert the optical beam at the first wavelength into an output optical beam at a second wavelength, and provide optically coupled feedback which is nonlinearly dependent on the power of the optical beam at the first wavelength to the laser.

2. The system of claim 1 wherein the laser comprises a semiconductor laser.

3. The system of claim 1 wherein the first wavelength is within an infrared range.

4. The system of claim 1 wherein the planar lightwave circuit comprises an arrayed waveguide grating.

5. The system of claim 4 wherein the arrayed waveguide grating comprises a silicon oxynitride waveguide.

6. The system of claim 1 wherein the waveguide optical frequency converter comprises a lithium tantalate waveguide.

7. The system of claim 1 wherein the waveguide optical frequency converter comprises an optical parametric oscillator.

8. The system of claim 1 wherein the waveguide optical frequency converter comprises a quasi-phase matched optical element.

9. The system of claim 1 wherein the second wavelength is a visible wavelength.

10. The system of claim 9 wherein the second wavelength is within a range selected from the group consisting of a range from about 450 nm to about 470 nm, a range from about 525 nm to about 545 nm, and a range from about 615 nm to about 660 nm.

11. The system of claim 1 further comprising a beam shaping element configured to shape the output optical beam from the waveguide optical frequency converter into a diffraction-limited optical beam having a brightness uniformity greater than approximately 95% across an approximately rectangular beam shape.

12. The system of claim 11 wherein the diffraction-limited optical beam is configured to have an optical power between approximately 1 watt and approximately 20 watts.

13. The system of claim 11 wherein the beam shaping element comprises an aspheric lens.

14. The system of claim 11 wherein the beam shaping element comprises an optical grating.

15. The system of claim 11 further comprising a spatial light modulator configured to modulate the diffraction-limited optical beam.

16. The system of claim 15 wherein the spatial light modulator comprises a micro-electro-mechanical system.

17. The system of claim 15 wherein the spatial light modulator comprises a liquid crystal device.

18. A system comprising:

a substrate;

a laser diode array disposed on the substrate and configured to emit a plurality of optical beams at a first wavelength;

a planar lightwave circuit disposed on the substrate and coupled to the laser diode array, and configured to combine the plurality of optical beams and produce a combined optical beam at the first wavelength; and

a nonlinear optical element disposed on the substrate and coupled to the planar lightwave circuit, and configured to;

convert the combined optical beam at the first wavelength into an optical beam at a second wavelength using nonlinear frequency conversion, and

provide optically coupled feedback which is nonlinearly dependent on a power of the combined optical beam at the first wavelength to the laser diode array.

19. The system of claim 18 further comprising a beam shaping element coupled to the nonlinear optical element, the beam shaping element configured to shape the optical beam at the second wavelength into an approximately rectangular diffraction-limited optical beam.

20. The system of claim 18 wherein the planar lightwave circuit comprises an arrayed waveguide grating.

21. The system of claim 18 wherein the nonlinear optical element comprises a quasi-phase matched optical waveguide.

22. The system of claim 18 wherein the nonlinear optical element comprises an optical parametric oscillator.

23. The system of claim 18 wherein the second wavelength is within a range selected from the group consisting of a range from about 450 nm to about 470 nm, a range from about 525 nm to about 545 nm, and a range from about 615 nm to about 660 nm.

24. A system comprising:

a semiconductor laser array configured to produce a plurality of optical beams at a first wavelength;

an arrayed waveguide grating coupled to the semiconductor laser array and configured to combine the plurality of optical beams and output a combined optical beam at the first wavelength;

a quasi-phase matching wavelength-converting waveguide coupled to the arrayed waveguide grating and configured to use second harmonic generation to produce an output optical beam at a second wavelength based on the combined optical beam at the first wavelength.

25. A method for illuminating a video display, the method comprising:

generating a diffraction-limited output optical beam using a system comprising

a laser diode array disposed on a substrate and configured to emit a plurality of optical beams at a first wavelength,

a planar lightwave circuit disposed on the substrate and coupled to the laser diode array, and configured to combine the plurality of optical beams and produce a combined optical beam at the first wavelength,

a nonlinear optical element disposed on the substrate and coupled to the planar lightwave circuit, and configured to convert the combined optical beam at the first wavelength into an optical beam at a second wavelength using nonlinear frequency conversion, and provide optically coupled feedback which is nonlinearly dependent on a power of the combined optical bean at the first wavelength to the laser diode array, and

a beam shaping element coupled to the nonlinear optical element and configured to shape the optical beam at the second wavelength into a diffraction-limited output optical beam; and

directing the diffraction-limited output optical beam using a spatial light modulator which is configured to project an image to a display screen.