Process and apparatus for generating at least three laser beams of different wavelength for the display of color video pictures

• US 6,233,025 B1
• Filed: 10/06/1998
• Issued: 05/15/2001
• Est. Priority Date: 09/08/1994
• Status: Expired due to Term

• Current Assignee: JENOPTIK LDT GmbH (Rheinmetall AG)
• Original Assignee: Ltd GmbH & Company Laser-Display-Technologie KG
• Inventors: Wallenstein, Richard
• Primary Examiner(s): Lee, Michael
• Application Number:
  US09/168,404
• Time in Patent Office: 952 Days
• Field of Search: H04/N.931, 348/750, 348/756, 348/757, 348/760, 348/754, 372/21, 372/22, 372/23, 372/94, 372/98, 372/99, 372/108, 359/330
• US Class Current: 348/750
• 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: 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

In a process for generating at least three laser beams of different wavelengths for displaying color video pictures, a pulsed laser is used to generate light. The light output of the pulsed laser is released in a pulse and is introduced into a medium with nonlinear optical characteristics for generating a laser beam. In addition to the laser beam generated by excitation, this medium releases an additional laser beam whose frequency is given by the sum or difference frequencies of the exciting laser beam and the excited laser beam due to the nonlinear optical characteristics of the medium. The laser beams generated by the medium in this way and the exciting laser beam are used directly, or after frequency conversion, to display monochromatic partial images of a color video picture. An apparatus according to the invention contains suitable devices for carrying out the process.

Claims

1. A three-color coherent light system, comprising:

a laser source for generating a laser beam;

an optical parametric oscillator for providing a signal beam and an idler beam;

means for supplying said laser beam to said optical parametric oscillator for pumping said optical parametric oscillator to produce said signal and idler beams;

means for providing said laser beam as a source of coherent green light;

means for generating the second harmonic of said signal beam as a source of coherent blue light; and

means for generating the second harmonic of said idler beam as a source of coherent red light.

2. The three-color coherent light system of claim 1, further comprising means responsive to said laser source for generating a second harmonic of said laser beam, said second harmonic of said laser beam being provided as the source of coherent green light and being provided for pumping said optical parametric oscillator.

3. The three-color coherent light system of claim 1, in which said laser source includes a solid state laser.

4. The three-color coherent light system of claim 2, in which said laser is Nd:

YVO₄.

5. The three-color coherent light system of claim 2, in which said laser is Nd:

YLF.

6. The three-color coherent light system of claim 1, in which said optical parametric oscillator includes a nonlinear LBO crystal.

7. The three-color coherent light system of claim 1, in which said optical parametric oscillator includes a nonlinear KTP crystal.

8. A three-color coherent light system, comprising:

an optical parametric oscillator for providing a signal beam and an idler beam;

means for providing a first laser beam for pumping said optical parametric oscillator to produce said signal and idler beams;

means for generating the second harmonic of said signal beam as a source of coherent blue light; and

means for generating the second harmonic of said idler beam as a source of coherent red light.

9. The three-color coherent light system of claim 8, wherein said optical parametric oscillator provides said first laser beam as an output source of coherent green light.

10. The three-color coherent light system of claim 8, further comprising a laser for providing an initial laser beam to said means for providing the first laser beam;

and wherein said means for providing the first laser beam generates a second harmonic of said initial laser beam and outputs the second harmonic of said initial laser beam as said first laser beam.

11. A three-color coherent light system, comprising:

a laser source for generating a laser beam;

an optical parametric oscillator for providing a signal beam and an idler beam;

means for supplying said laser beam to said optical parametric oscillator for pumping said optical parametric oscillator to produce said signal and idler beams;

means for adjusting said optical parametric oscillator by using the light intensity of said signal beam or of said idler beam or of a combination thereof, and adjusting the temperature of said optical parametric oscillator to readjust the wavelength of said signal beam and said idler beam;

means for providing said laser beam as a source of coherent green light;

means for generating the second harmonic of said signal beam as a source of coherent blue light; and

means for generating the second harmonic of said idler beam as a source of coherent red light.

12. A three-color coherent light system, comprising:

an optical parametric oscillator for providing a signal beam and a idler beam;

means for providing a first laser beam for pumping said optical parametric oscillator to produce said signal and idler beams;

means for adjusting said optical parametric oscillator by using the light intensity of said signal beam or of said idler beam or of a combination thereof and adjusting the temperature of said optical parametric oscillator to readjust the wavelength of said signal beam and said idler beam;

means for generating the second harmonic of said signal beam as a source of coherent blue light, and

means for generating the second harmonic of said idler beam as a source of coherent red light.