Design of Mirror and Catadioptric Systems

1. It has both coma and astigmatism if the stop not at focus.

2. aperture located at the plane of a focus -> image is free of astigmatism

3. Paraboloid Reflector

3.1. generated by rotation of the conic sections circle

3.2. object imaged at the focus without spherical aberration

4. Schmidt System

4.1. consists of a spherical reflector with an aspheric corrector plate at its center of curvature

4.2. spherical aberration corrected by the corrector plate

4.3. higher-order forms of astigmatism.

5. Mangin Mirror

5.1. combined reflecting and refracting

5.2. consist of two surfaces spherical mirrors

5.3. the first surface chosen to correct the spherical aberration

5.4. one radius is chosen arbitrarily

5.5. other radius is varied systematically until the spherical aberration is corrected

6. Maksutov System

6.1. extension of the Mangin mirror principle

6.2. correcting lens is separated from the mirror

6.3. combined with a Schmidt-type aspheric corrector plate to correct chromatic

7. For distant objects -> undercorrected spherical aberration

8. object located at one focal point of a conic --> the image located at the other focal point, no spherical aberration

9. Reflecting Systems

9.1. need increase because the difficulty to find satisfactory refractive materials for non visible spectrum

10. Spherical Mirror

10.1. The aberration is only one-eighth of that of an equivalent glass lens

10.2. If the stop at its center of curvature the image is free of coma and astigmatism

11. Ellipsoid and Hyperboloid

11.1. arranged to correct coma, astigmatism and spherical

11.2. negative lens near the secondary to correct the coma.

11.3. doublet near focus to correct the astigmatism and Petzval

12. Conic Section

12.1. aperture located in the plane of a focal point --> no astigmatism