Optical Design Study 1

Doublet lens

1. Design an f/4 achromatic N-SK4/N-SF5 doublet lens with focal length 50 mm and 4-degree half field-of-view. Find both solutions with the crown element in front. Comment on the relative merits of each design.

2. Make the position of the stop a variable and design a “landacape lens” achromatic doublet. Discuss the performance of this design compared to the doublet with the stop at the first surface.

3. If your Fraunhoffer lens is “almost” cemented, remove the air interface (surface 2) and reoptimize. Comment on the relative merits of this design compared to the “separated” lens Fraunhoffer design.

4. Analyze at least one of your designs in MATLAB by generating a diagram of your lens, a paraxial raytrace, and a table of Seidel wavefront aberrations. The results should match ZEMAX. See the example MATLAB script.

5. The MATLAB lens drawing is designed to be solid-shaded. Paste your drawing into Powerpoint, convert to a Microsoft drawing object (by ungrouping), right click on each lens and make a closed curve. Then set object properties to make a solid outline and filled interior. See these example lens drawings.

For each lens design, submit your .ZMX file and provide a report with the following information:

1. drawing of the lens
2. a full listing of lens data
3. chromatic focal shift
4. rms spot radius vs. field
5. a rayfan analysis figure
6. field curvature/distortion figure
7. a spot diagram figure (through focus)
8. paraxial raytrace
9. Seidel wavefront aberration table

See the example: Achromatic doublet design

Maintained by John Loomis, last updated 23 May 2012