Claims
- 1. A method of optically imaging, comprising:
propagating light through a plurality of cubic crystal elements possessing intrinsic birefringence that produce first retardance aberrations; and propagating said light through one or more optical elements comprising a uniaxial birefringent medium thereby introducing second retardance aberrations substantially identical in magnitude and substantially conjugate in shape to said first retardance aberrations so as to substantially offset said first retardance aberrations.
- 2. The method of claim 1, wherein said plurality of cubic crystal elements are clocked such that said second retardance aberrations are substantially identical in magnitude and substantially conjugate in shape to said first retardance aberrations.
- 3. The method of claim 1, wherein said plurality of cubic crystal elements are clocked such that said first retardance aberrations are substantially circularly symmetric about an optical axis passing through said plurality of cubic crystal elements.
- 4. The method of claim 1, wherein said plurality of cubic crystal elements are clocked so as to provide radially directed local retardance axes substantially completely around an optical axis passing through said plurality of cubic crystal elements at least for light propagating from an on-axis field point.
- 5. The method of claim 1, wherein said plurality of cubic crystalline optical elements imparts retardance of at least about 0.1 RMS waves for an on-axis field and a numerical aperture of greater than about 0.7.
- 6. The method of claim 1, wherein said first retardance aberrations are reduced to about 0.05 RMS waves or less when combined with said second retardance aberrations.
- 7. The method of claim 1, further comprising imposing a stress on said at least one optical element comprising an optical plate to induce uniaxial birefringence.
- 8. The method of claim 1, further comprising imposing a stress on the perimeter of front and rear surfaces of said optical element to induce uniaxial birefringence, said light propagating through said at least one optical element is incident on said front face and exits said rear face.
- 9. The method of claim 1, further comprising imposing a stress between about 100 to about 1000 pounds per square inch on said at least one optical element to induce uniaxial birefringence.
- 10. The method of claim 1, further comprising imposing a stress on said at least one [111] cubic crystalline optical element to induce uniaxial birefringence.
- 11. The method of claim 1, wherein said plurality of cubic crystal elements comprise [111] cubic crystal.
- 12. A method of reducing the retardance caused by intrinsic birefringence in an optical system comprising a plurality of [111] cubic crystalline optical elements with respective [111] crystal axes aligned along an optical axis, said method comprising:
clocking at least one said [111] cubic crystalline optical element to provide a more circularly symmetric retardance pattern over a pupil centered about said optical axis at least for on-axis field points; and introducing one or more uniaxial birefringent elements comprising media having a single birefringence axis into said optical system, said one or more uniaxial birefringent elements having a substantially circularly symmetric retardance pattern associated therewith that is distributed over said pupil centered about said optical axis at least for on-axis field points, wherein said retardance pattern corresponding to said plurality of [111] cubic crystal optical elements and said retardance pattern corresponding to said one or more uniaxial birefringent elements are opposite such that retardance introduced into an optical beam transmitted through said plurality of [111] cubic crystalline elements is substantially offset by retardance introduced into said optical beam upon transmitting said beam through said one or more uniaxial birefringent optical elements.
- 13. The method of claim 12, wherein at least one of said [111] cubic crystalline optical elements is clocked sufficiently to provide said circularly symmetric retardance pattern with radially directed local retardance axes substantially throughout said retardance pattern over said pupil.
- 14. The method of claim 12, wherein at least one of said [111] cubic crystalline optical elements is clocked sufficiently to provide substantially constant magnitude local retardance about concentric circular paths around said optical axis.
- 15. The method of claim 12, wherein said introducing comprises providing one or more optical elements comprising form birefringence media.
- 16. The method of claim 12, wherein said media having a single birefringence axis includes at least one multilayer form birefringence film comprising multiple layers each having a thickness of less than a wavelength.
- 17. The method of claim 12, wherein said media having single birefringence axis includes at least one composite form birefringent structure comprising a plurality of microstructures imbedded in a material.
- 18. The method of claim 12, wherein said optical system has a numerical aperture of at least about 0.5 and a net retardance of less than about 0.05 RMS waves.
- 19. The method of claim 12, wherein said pupil corresponds to a numerical aperture of at least about 0.5.
- 20. An optical method comprising:
propagating a beam of light having first and second orthogonal polarization components through first optics comprising a plurality of optical elements disposed along an optical axis, said first optics having radial and tangential eigenpolarization states that form a circularly symmetric pattern around said optical axis, said radial and tangential eigenpolarization states being phased delayed with respect to each other so as to introduce phase delay between said first and second orthogonal polarization components in said beam of light; and substantially reducing said phase delay between said first and second orthogonal polarization components in said beam of light by propagating said light through second optics disposed along said optical axis, said second optics having radial and tangential eigenpolarization states that form a circularly symmetric pattern around said optical axis, said radial and tangential eigenpolarization states in said second optics being phased delayed with respect to each other opposite said phase delay between said radial and tangential eigenpolarization states of said first optics section.
PRIORITY APPLICATION
[0001] This application claims the benefit of priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. ______ (Docket No. OPTRES.007PR2), filed Dec. 11, 2002 and entitled “Reduced Aberration in Optical Systems” as well as U.S. Provisional Patent Application No. 60/405,853, filed Aug. 22, 2002 and entitled “New Method of [111] Compensation Using Stress”.
Provisional Applications (2)
|
Number |
Date |
Country |
|
60432688 |
Dec 2002 |
US |
|
60405853 |
Aug 2002 |
US |