Conformal window design with static and dynamic aberration correction

• US 6,018,424 A
• Filed: 12/11/1996
• Issued: 01/25/2000
• Est. Priority Date: 12/11/1996
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Cook, Lacy, Morgan, Darcy J.
• Primary Examiner(s): Epps, Georgia Y.
• Assistant Examiner(s): SCHWARTZ, JORDAN MARC
• Application Number:
  US08/764,413
• Time in Patent Office: 1,140 Days
• Field of Search: 359/708, 359/554, 359/557, 359/712, 359/613, 359/234, 359/236
• US Class Current: 359/708
• CPC Class Codes: G02B 26/06 for controlling the phase of light G02B26/08 takes precedence , measuring optical phase difference G01J9/00
• CPC Class Codes: G02B 27/0025 for optical correction, e.g. distorsion, aberration

Abstract

A system for correcting optical aberration created by a conformal window has a conformal window (12) with an outer surface (26) and an inner surface (28). The inner surface (28) is an aspheric surface for compensating for higher order aberrations. An aberration generator (16) is aligned to receive input from the conformal window (12) and dynamically corrects lower order aberrations, notably focus and astigmatism, over the field of regard.

Claims

1. A system for correcting optical aberration created by a conformal window comprising:

a conformal window having an outer surface and an inner surface, said inner surface being aspheric for compensating for higher order aberrations; and

an aberration generator having a field of regard and aligned to receive input from said conformal window, said aberration generator dynamically correcting aberrations over the field of regard, said aberration generator compensating for lower order aberrations.

2. The system according to claim 1, wherein said conformal window outer surface is an off-axis portion of a paraboloid for improving aerodynamic performance.

3. The system according to claim 1, wherein said conformal window inner surface is a bilaterally symmetric Zernike described aspheric.

4. The system according to claim 1, wherein said aberration generator includes at least two lenses, said lenses being axially and rotatably movable.

5. The system according to claim 4, wherein said aberration generator focuses and compensates for astigmatism.

6. A conformal window for use in an aircraft between an inner optical device and an outer environment wherein electromagnetic radiation is conveyed between said outer environment and said optical device through said window and wherein said optical device has a field of regard through said window, said window comprising:

an outer surface facing said outer environment having a configuration of an off-axis portion of a paraboloid to optimize aerodynamic properties, said configuration generating lower order aberrations and higher order aberrations through said optical device field of regard; and

an inner surface facing said optical device having an aspheric surface for compensating said higher order aberrations generated by said outer surface through said field of regard.

7. The system according to claim 6, wherein said conformal window inner surface is a bilaterally symmetric Zernike described aspheric.

8. The conformal window according to claim 7, wherein the inner surface is parabolic.

9. The conformal window according to claim 8, wherein the inner surface is defined by a Zernike polynomial where ##EQU3##10.

10. An optical sensor assembly comprising:

a conformal window including an outer and inner surface, said inner surface being aspheric for compensating for higher order aberrations;

an aberration generator having a field of regard and aligned to receive input from said conformal window, said aberration generator dynamically correcting aberrations over said field of regard, said aberration generator compensating for lower order aberrations; and

said aberration generator comprising an optical system and wherein said conformal window inner surface and aberration generator compensate for optical aberration created at every position within the field of regard of the optical sensor.

11. The optical sensor assembly according to claim 10, wherein said conformal window outer surface is an off-axis portion of a paraboloid for improving aerodynamic performance.

12. The optical sensor assembly according to claim 10, wherein said conformal window inner surface is a bilaterally symmetric Zernike described aspheric.

13. The optical sensor assembly according to claim 10, wherein said aberration generator includes at least two lenses, said lenses being axially and rotatably movable.

14. The optical sensor assembly according to claim 13, wherein said aberration generator focuses and compensates for astigmatism.

15. The optical sensor assembly according to claim 10, wherein said aberration generator includes three lenses being axially and rotatably movable.