Atmospheric compensation disc

Patent metadata

Field	Value
Publication number	US-12085729-B2
Application number	US-202217583421-A
Country	US
Kind code	B2
Filing date	Jan 25, 2022
Priority date	Jan 25, 2022
Publication date	Sep 10, 2024
Grant date	Sep 10, 2024

Abstract

An atmospheric distortion compensator comprising a disc and a rotator. The disc, which comprises a phase-modifying structure, is rotationally balanced about a center point. The rotator is mechanically coupled to the disc's center point and configured to spin the disc about an axis. When spinning, the disc is configured to control a property of a beam, which is propagating in parallel to the axis and impinging on the disc. By so doing, scintillation effects within an electro-optical field caused by propagation of the beam within a heterogeneous medium are reduced.

First claim

I claim:

1. An atmospheric distortion compensator comprising:
a disc that is rotationally balanced about a center point and that comprises a phase-modifying structure;
an optical beam source configured to generate a LASER that is fully coherent and narrow-band, wherein the optical beam source is positioned with respect to the disc such that the LASER propagates through the disc and then into a heterogeneous medium;
a rotator mechanically coupled to the disc's center point and configured to spin the disc about an axis parallel to the LASER, wherein the disc, when spinning, is configured to control a property of the LASER so as to reduce scintillation effects caused by propagation of the LASER through the heterogeneous medium;
wherein the disc further comprises a plurality of N tracks, wherein each track is configured to apply a different degree of partial coherence to the LASER, and wherein the tracks are disposed on the disc such that the LASER may be brought into contact with different tracks by moving the disc in a direction that is orthogonal to the LASER, and wherein one of the tracks is a reference track, which is configured with a uniform phase profile to not distort the LASER;
a processor operatively coupled to the rotator;
a linear actuator that is coupled to the disc, wherein the processor is configured to instruct the linear actuator to move the disc in a direction that is orthogonal to the LASER so as to bring the LASER into contact with different tracks until a desired track is identified that most reduces scintillation effects of the LASER caused by atmospheric turbulence as compared to the reference track that has a uniform phase profile; and
wherein the LASER is a pulsed LASER, and wherein a spin rate of the disc is tied to a repetition rate of the pulsed LASER to ensure independent phase realizations are imparted on the pulsed LASER so as not to get stuck in frequency nodes between the spin rate of the disc and the repetition rate of the pulsed LASER.

2. The atmospheric distortion compensator of claim 1 , wherein the spin rate of the disc is adjusted depending on an area of a given track.

3. An atmospheric distortion compensator comprising:
a disc that is rotationally balanced about a center point and that comprises a phase-modifying structure, wherein the disc further comprises a plurality of N tracks, wherein each track is configured to apply a different degree of partial coherence to the optical beam, wherein the tracks are disposed on the disc such that the optical beam may be brought into contact with different tracks by moving the disc in a direction that is orthogonal to the optical beam, and wherein one of the tracks is a reference track, which is configured with a uniform phase profile to not distort the optical beam;
an optical beam source configured to generate an optical beam, wherein the optical beam source is positioned with respect to the disc and an object such that the optical beam illuminates the object after first passing through the disc and then through a heterogeneous medium;
a rotator mechanically coupled to the disc's center point and configured to spin the disc about an axis parallel to the optical beam, wherein the disc, when spinning, is configured to control a property of the optical beam so as to reduce scintillation effects caused by propagation of the optical beam through the heterogeneous medium;
a camera disposed to capture an image of the object while illuminated by the optical beam;
a processor configured to adjust a rotational speed of the disc, wherein the processor is configured to spin the disc at a rate that is at least 30 times greater than an integration time of the camera;
a linear actuator operatively coupled to the processor, which is configured to instruct the linear actuator to move the disc in a direction that is orthogonal to the optical beam so as to bring the optical beam into contact with different tracks until a desired track is identified that most reduces scintillation effects of the optical beam caused by atmospheric turbulence as compared to the reference track; and
wherein the optical beam is a pulsed LASER, a spin rate of the disc is tied to a repetition rate of the pulsed LASER to ensure independent phase realizations are imparted on the optical beam rather than getting stuck in frequency nodes between the spin rate of the disc and the repetition rate of the pulsed LASER.

Assignees

• Us Navy
• Us Navy

Inventors

• Drexler Kyle Robert

Classifications

• G02B27/0037

  with diffracting elements (G02B27/0056 takes precedence; holographic optical elements G02B5/32; zone systems G02B5/1876) · CPC title

• G02B27/48

  Laser speckle optics · CPC title

• G02B27/0025

  for optical correction, e.g. distorsion, aberration · CPC title

• G02B27/0068

  having means for controlling the degree of correction, e.g. using phase modulators, movable elements (controlling the phase of light using moving or deformable elements G02B26/06) · CPC title

• G02B26/06

  for controlling the phase of light (G02B26/08 takes precedence {, measuring optical phase difference G01J9/00}) · CPC title