Optical phase conjugate beam modulator and method therefor

• US 4,921,335 A
• Filed: 09/01/1988
• Issued: 05/01/1990
• Est. Priority Date: 09/01/1988
• Status: Expired due to Fees

• Current Assignee: the united states of america as represented by the secretary of the navy
• Original Assignee: the united states of america as represented by the secretary of the navy
• Inventors: Ditman, L. Samuel Jr.
• Primary Examiner(s): LaRoche, Eugene R.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/239,498
• Time in Patent Office: 607 Days
• Field of Search: 350/354, 350/3.67, 350/3.68, 350/3.64, 372/21, 372/22
• US Class Current: 359/241
• CPC Class Codes: G02F 1/3538 for optical phase conjugation controlling the intensity, frequency, phase, polarisation or direction of the emitted radiation using optical phase conjugation H01S3/10076

Abstract

The present invention relates to the modulation of a phase conjugate beam. A writing beam is directed incident to a phase conjugate reflector. A modulating beam is also directed incident to the phase conjugate reflector for amplitude modulation of the phase conjugate beam. The modulating beam can also be steerable for effecting the amplitude of the phase conjugate beam according to spatial distribution so as to spatially modulate the phase conjugate beam. The phase conjugate modulation thus can be accomplished by opto-optical means and without modulation of or effect on the incident writing beam.

Claims

1. A phase conjugate beam modulator system, comprising:

phase conjugate reflector means for reflecting a writing beam incident thereupon as a phase conjugate beam, and optical modulating means directing a modulating light beam incident upon the reflector means for modulation of the phase conjugate beam independently of the writing beam.

2. The system of claim 1 wherein the reflecting means is self-pumping.

3. The system of claim 1 further comprising means for steering the modulating light beam.

4. The system of claim 1 further comprising means for steering the phase conjugate beam.

5. The system of claim 1 wherein the modulating light beam is amplitude modulated.

6. In combination with a self-pumped, phase conjugate reflector device having a radiation incident surface;

a method of amplitude modulating a phase conjugate beam derived from a single input beam of coherent radiation passing internally through the reflective device, including the steps of;

selectively applying the input beam to the reflector device through said incident surface along an intersecting path common to the phase conjugate beam propagated in a reverse direction from the reflection device; and

applying a modulating beam independent of the input beam to the reflector device along a separate path substantially perpendicular to a plane at right angle to said incident surface to modulate the phase conjugate beam without affecting the input beam externally of the reflector device.

7. The method of claim 6 including the step of:

selecting an angle of incidence between the input beam and the incident surface to establish said common path for th input beam and the phase conjugate beam externally of the reflector device.

8. The method of claim 7 including the step of:

deflecting the modulated phase conjugate beam externally of the reflector device from the common path.

9. The method of claim 6 including the step of:

deflecting the modulated phase conjugate beam externally of the reflector device from the common path.