Optical System and Assembly Method

• US 20100253769A1
• Filed: 09/03/2009
• Published: 10/07/2010
• Est. Priority Date: 09/04/2008
• Status: Abandoned Application

• Current Assignee: Projection Ventures Inc.
• Original Assignee: Laser Light Engines, Inc.
• Inventors: Goodwin, David, Zambuto, James J., Coppeta, David A., Beck, William, Turner, Ian
• Application Number:
  US12/553,890
• Publication Number:
  US 20100253769A1
• Time in Patent Office: Days
• US Class Current: 348/58
• CPC Class Codes: G02B 27/1026 for use with reflective spatial light modulators
• CPC Class Codes: G02B 27/1046 for use with transmissive spatial light modulators
• CPC Class Codes: G02B 27/1073 characterized by manufacturing or alignment methods
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: G02B 27/286 for controlling or changing the state of polarisation, e.g. transforming one polarisation state into another G02B5/3083 takes precedence; light guide coupling means utilising polarising elements G02B6/34
• CPC Class Codes: G02B 27/48 Laser speckle optics
• CPC Class Codes: G02B 30/24 involving temporal multiplexing, e.g. using sequentially activated left and right shutters
• CPC Class Codes: G02B 30/25 using polarisation techniques
• 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: H01S 3/005 Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B
• CPC Class Codes: H01S 3/0092 Nonlinear frequency conversion, e.g. second harmonic generation [SHG] or sum- or difference-frequency generation outside the laser cavity nonlinear frequency conversion per se G02F1/35
• CPC Class Codes: H01S 3/0606 with polygonal cross-section, e.g. slab, prism H01S3/0604 takes precedence
• CPC Class Codes: H01S 3/0941 of a laser diode
• CPC Class Codes: H01S 3/1611 neodymium
• CPC Class Codes: H01S 3/23 Arrangements of two or more lasers not provided for in groups H01S3/02 - H01S3/22, e.g. tandem arrangements of separate active media
• CPC Class Codes: H01S 3/2325 Multi-pass amplifiers, e.g. regenerative amplifiers
• CPC Class Codes: H01S 3/2383 Parallel arrangements
• CPC Class Codes: H01S 3/2391 : emitting at different wavelengths
• CPC Class Codes: H04N 13/324 : Colour aspects
• CPC Class Codes: H04N 13/327 : Calibration thereof
• CPC Class Codes: H04N 13/334 : using spectral multiplexing
• CPC Class Codes: H04N 13/337 : using polarisation multiplexing
• CPC Class Codes: H04N 13/341 : using temporal multiplexing
• CPC Class Codes: H04N 13/363 : using image projection screens volumetric display H04N13/388
• CPC Class Codes: H04N 9/3105 : for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10
• CPC Class Codes: H04N 9/3161 : using laser light sources using laser beams scanning the display screen H04N9/3129
• CPC Class Codes: Y10T 29/49901 : Sequentially associating parts on stationary aligning means

Abstract

An optical system which includes some or all of the following parts: a laser light source which illuminates a spatial light modulator such that optical characteristics are preserved; a stereoscopic display which has a polarization-switching light source; a stereoscopic display which includes two infrared lasers, two optical parametric oscillators, and six second harmonic generators; two light sources processed by two parts of the same spatial light modulator; a method of assembly using an alignment plate to align kinematic rollers on a holding plate; an optical support structure which includes stacked, compartmented layers; a collimated optical beam between an optical parametric oscillator and a second harmonic generator; a laser gain module with two retroreflective mirrors; an optical tap which keeps the monitored beam co-linear; an optical coupler which includes an optical fiber and a rotating diffuser; and an optical fiber that has a core with at least one flat side.

Claims

1. An optical system comprising:

a blue light source;

a spatial light modulator (SLM);

wherein the blue light source emits light only in a range of wavelengths that preserves an optical characteristic of the SLM.

2. The system of claim 1 wherein the blue light source comprises a laser.

3. The system of claim 1 wherein the SLM comprises a liquid crystal material.

4. A stereoscopic display system comprising:

a polarization-switching light source characterized by a polarization state; and

a polarization-preserving projector which is illuminated by the polarization-switching light source.

5. The system of claim 4 wherein the polarization-preserving projector forms a left-eye digital image and a right-eye digital image, and the polarization state is changed in synchronization with an alternating projection of the left-eye digital image and the right-eye digital image.

6. A stereoscopic projection system comprising:

a first infrared laser;

a first gain module that amplifies a light beam from the first infrared laser;

a first second-harmonic generator (SHG) that frequency doubles a light beam from the first gain module;

a first optical parametric amplifier (OPO) that parametrically amplifies a light beam from the first SHG;

a second SHG that frequency doubles a first light beam from the first OPO;

a third SHG that frequency doubles a second light beam from the first OPO;

a second infrared laser;

a second gain module that amplifies a light beam from the second infrared laser; and

a fourth SHG that frequency doubles a light beam from the second gain module;

wherein part of the light beam from the first SHG passes through the first OPO to form a remaining light beam, the remaining light beam has a first wavelength of green light, a light beam from the second SHG has a first wavelength of red light, a light beam from the third SHG has a first wavelength of blue light; and

a light beam from the fourth SHG has a second wavelength of green light.

7. The system of claim 6 wherein the remaining light beam, the light beam from the second SHG, and the light beam from the third SHG combine to form an image that is directed to one eye of a viewer and not directed to the other eye of the viewer.

8. The system of claim 6 further comprising:

a switch that switches the light beam from the first SHG;

a second OPO that parametrically amplifies the light beam from the first SHG;

a fifth SHG that frequency doubles a first light beam from the second OPO; and

a sixth SHG that frequency doubles a second light beam from the second OPO;

wherein the switch sends the light beam from the first SHG alternately to the first OPO and the second OPO, and a light beam from the fifth SHG has a second wavelength of red light, and a light beam from the sixth SHG has second wavelength of blue light.

9. The system of claim 6 further comprising:

a third infrared laser;

a third gain module that amplifies a light beam from the third infrared laser;

a fifth SHG that frequency doubles a light beam from the third gain module;

a second OPO that parametrically amplifies a light beam from the fifth SHG;

a sixth SHG that frequency doubles a first light beam from the second OPO; and

a seventh SHG that frequency doubles a second light beam from the second OPO;

wherein a light beam from the sixth SHG has a second wavelength of red light, and a light beam from the seventh SHG has a second wavelength of blue light.

10. An optical system comprising:

a first light source;

a second light source; and

an SLM;

wherein the first light source has a first optical output which is processed by a first part of the SLM and the second light source has a second optical output which is processed by a second part of the SLM.

11. The system of claim 10 wherein the first light source has an etendue lower than 0.1 mm² sr.

12. The system of claim 10 wherein the first part of the SLM is used to form an image for a left eye of a viewer and the second part of the SLM is used to form an image for a right eye of the viewer.

13. The system of claim 10 wherein the first optical output comprises a first wavelength band and the second optical output comprises a second wavelength band;

the first wavelength band being distinct from the second wavelength band.

14. A method of assembly comprising:

placing an alignment plate on a holding plate;

inserting a roller and a holding block into the alignment plate;

fastening the holding block to the holding plate to hold the roller;

fastening the roller to the holding plate;

removing the alignment plate; and

mating an optical module to the roller on the holding plate.

15. The method of claim 14 further comprising:

achieving final optical alignment without further adjustments.

16. An optical support structure comprising:

a first compartmented support structure adapted to support optical modules; and

a second compartmented support structure adapted to support optical modules;

wherein the second compartmented support structure is stacked on top of the first compartmented support structure.

17. The structure of claim 16 further comprising:

a first compartment in the first compartmented support structure;

a second compartment in the second compartmented support structure; and

a hole between the first compartment and the second compartment that allows a beam of light to pass between the first compartment and the second compartment.

18. The structure of claim 16 further comprising:

a third compartment in the second support structure; and

a hole between the second compartment and the third compartment that allows a beam of light to pass between the second compartment and the third compartment.

19. The structure of claim 16 further comprising:

a kinematic mount on the first compartmented support structure; and

a kinematic mount on the second compartmented support structure;

wherein the kinematic mount on the second compartmented support structure is mated to the kinematic mount on the first compartmented support structure.

20. An optical system comprising:

an OPO;

an SHG;

a first lens which passes light between the OPO and the SHG;

a second lens which passes light between the OPO and the SHG; and

a third lens which passes light between the OPO and the SHG.

21. The system of claim 20 wherein the first lens passes a collimated beam segment to the second lens.

22. An apparatus comprising:

a laser gain slab which carries a main laser beam;

a pump laser which optically pumps the laser gain slab; and

a retroreflective mirror positioned adjacent to the laser gain slab;

wherein the retroreflective minor reflects the main laser beam.

23. An optical tap comprising:

a first plate;

a second plate; and

a detector;

wherein a first beam of light enters the first plate, the first beam of light exits the first plate to form a second beam of light, the second beam of light enters the second plate, the second beam of light exits the second plate to form a third beam of light, the second plate forms the third beam of light to be co-linear with the first beam of light, the first beam of light is reflected from a plate selected from the group consisting of the first plate and the second plate to form a fourth beam of light, the fourth beam of light is a small fraction of the first beam of light, and the fourth beam of light illuminates the detector.

24. The tap of claim 23 further comprising:

a third plate;

wherein after the first beam of light reflects from the plate selected from the group consisting of the first plate and the second plate, the first beam of light reflects from the third plate to form the fourth beam of light.

25. The tap of claim 23 wherein the first plate comprises an uncoated plate of glass.

26. An optical coupler comprising:

a first optical fiber; and

a despeckler;

wherein a first laser light beam illuminates the first optical fiber;

an output from the first optical fiber illuminates an integrating rod; and

an output from the integrating rod illuminates a digital image projector.

27. The coupler of claim 26 further comprising:

a second optical fiber;

wherein a second laser light beam illuminates the second optical fiber; and

an output from the second optical fiber illuminates the despeckler.

28. The coupler of claim 27 further comprising:

a third optical fiber;

wherein a third laser light beam illuminates the third optical fiber;

an output from the third optical fiber illuminates the despeckler;

the first laser light beam is red;

the second laser light beam is green; and

the third laser light beam is blue.

29. The coupler of claim 27 wherein the first optical fiber is attached to the second optical fiber to form an optical fiber bundle.

30. An optical system comprising:

a first laser light source;

an optical fiber with a core; and

a digital image projector;

wherein an output of the first laser light source illuminates the core, an output of the core illuminates the digital image projector, and the core has at least one flat side.

31. The system of claim 30 wherein the core has a rectangular cross section.

32. The system of claim 31 wherein the output of the first laser light source has a polarization direction and the polarization direction is oriented orthogonal to the flat side.