Claims
- 1. A method for assessing a surface configuration of a concave conacoid optical element having a conic constant closer to the conic constant of a paraboloid than to the conic constant of a sphere, comprising the steps of:
- a. generating a correcting lens designed to correct spherical aberration associated with aparaboloidal departure of said optical element relative to a parabaloid mathematically best fit to the surface of said element;
- b. interposing said correcting lens between the surface of said concave conacoid optical element and a focal point of said element; and
- c. subjecting the optical element with correcting lens to a classical collimation testing procedure for ascertaining its surface configuration relative to said paraboloid.
- 2. The method of claim 1 wherein the conacoid optical element defines a hyperboloid.
- 3. The method of claim 1 wherein the conacoid optical element defines a prolate ellipsoid.
- 4. The method of claim 1 wherein said correcting lens provides a correction of the optical element to less than 0.001 wave length of visible light.
- 5. The method claimed in claim 1, wherein said step of generating a correcting lens comprises the steps of:
- a. selecting a material for a lens element;
- b. selecting a lens thickness;
- c. selecting radii of curvature of the lens surfaces;
- d. selecting a separation of the lens and the vertex of the optical element;
- e. entering the optical element-correcting lens configuration into a commercial computerized lens-design program;
- f. simulating an axial point offset at infinite distance, projecting light parallel to the axis of symmetry of the optical element;
- g. utilizing the lens-design program to vary the radii of the correcting lens surfaces independently to minimize spherical aberration; and
- h. examining the correcting lens size and shape and
- i. if it is undesirably large, increase the separation between the optical element and the correcting lens and repeat steps e through h,
- ii. if the radii of the correcting lens surfaces are too short, increase the thickness of the correcting lens and repeat steps e through h.
Parent Case Info
This is a continuation of application Ser. No. 07/853,478, filed on Mar. 18, 1992 now abandoned.
US Referenced Citations (4)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0115461 |
Aug 1984 |
EPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
853478 |
Mar 1992 |
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