The 2017 IODC Shafer Cup Competition

The Centennial Lens

2016 is the 100th anniversary of the Optical Society of America – its Centennial year. To celebrate this, the 2017 IODC Lens Design Problem (announced in 2016) has a centennial theme.

The problem is to design a lens which includes a “100 lens” somewhere within the overall lens to commemorate OSA’s 100th anniversary. The 100 lens comprises a 10 mm thick flat plate and two ball lenses 40 mm in diameter, as shown in Figure 1. The flat plate is 5 mm from the first ball lens and the two ball lenses are separated by 5 mm, so the overall length of the 100 lens is 100 mm, continuing the centennial theme. There is no limit to the number of lenses before or after the 100 lens, but there may not be any additional optical elements within the 100 lens.

The goal of the problem is to maximize the used portion of the diameters of the two ball lenses.

[table caption=”

Specifications

” colwidth=”120|300″ th=”0″]
Focal length:|                   Not specified.

Entrance pupil diameter:|  Not specified.

F/number:|                       Not specified.

Field of view:|                  Not specified.

Number of lenses:|           Not specified.

Overall length:|                Not specified.

Maximum diameter:|        Not specified.

Distortion:|                       Not specified.

Stop location:|                  No restrictions.

Lens type:|                       All refractive; no reflectors or TIR.

Lens configuration:|          Rotationally symmetric; must include the “100 lens.”

Surface shape:|                 Spherical or plano only (no aspheres).

Wavelength:|                    587.56 nm (monochromatic).

Glass:|                              Schott N-BK7.

Object:|                            At infinity.

Image:|                             Flat image plane in air.

Image distance:|               Non-negative.

Vignetting:|                      Aperture stop is fully filled at all points in the field of view.

Image quality:|                 RMS wavefront error ≤ 0.070 wave over the field of view (piston and tilt removed; focus not removed).
[/table]

Merit Function

 

The goal of the problem is to use as much of the diameters of the two ball lenses as possible while maintaining diffraction-limited performance across the field of view. To preclude on-axis only solutions and encourage larger fields of view, the merit function is the product of two quantities: (1) the largest on-axis marginal ray height on any of the four ball lens surfaces, and (2) the largest full-field chief ray height on any of the four ball lens surfaces. Note that the largest on-axis marginal ray height and the largest full-field chief ray height may occur on different surfaces. Since the semi-diameters of the ball lenses are 20 mm, the maximum possible merit function is 400.

Submissions

The coveted Shafer Cup will be awarded to the entry with the highest merit function and a separate Shafer Cup will be awarded to the best entry from a student (undergraduate or graduate). Send your entry to rcjuergens@msn.com. Entrants may submit more than one entry, but only the one with the highest merit function will be considered. Please include the following information with your submission:

• Name,
• Affiliation (if an educational institution, indicate if you are a student; if you are a graduate student, please indicate your advisor),
• Country,
• Approximate number of years of lens design experience you have,
• Lens design program(s) used,
• Lens file (text format) or lens prescription,
• Lens layout (to verify the prescription is correct),
• Your values for maximum heights of the on-axis marginal ray and the full-field chief ray on any of the four ball lens surfaces (although they will also be computed by the evaluator),
• Approximate number of hours you spent on the problem (not counting the time any global optimizers were grinding away on their own), and
• Indicate whether you used a global optimizer on the problem or not.
• (Optional) Describe your design methodology (warning – may be used in the talk and/or the written paper if it is unique enough or interesting enough).

Lens files for CODE V, OSLO, and Zemax can be read directly by the evaluator. For all other programs, include a lens prescription with a sufficient number of significant digits in a readily understandable text format. All entries will be converted to CODE V format for common verification of compliance to the specifications and evaluation of the merit function.

All entries must be received by midnight, Pacific Daylight Time, May 1, 2017. If you have any questions about the problem, refer to the frequently asked questions (FAQ) page on the IODC web site, or contact Richard Juergens at rcjuergens@msn.com.