How can you split someone up and put them back together? This was the illumination design problem posed at the 2021 International Optical Design Conference (IODC), hosted by the Optical Society of America, now Optica.
At every IODC, optical designers are invited to participate in a competition to solve lens and illumination design problems created by committees. The problems are intentionally hypothetical, extremely difficult to solve, and are purely for entertainment.
A member of our Optical Solutions team, Dr. Jake Jacobsen, used LightTools illumination design software to solve the 2021 illumination problem. What was the design problem and how did he produce the solution?
The background of the 2021 problem was a fantastical story about Prince Lambert, who was sleeping peacefully in his bed when the evil wizard Étendue cast a curse on him using a mystery optical system, splitting him into two million pieces. The challenge was to create an optical system to put as much of poor Prince Lambert back together as possible, preferably in the right order.
As part of the problem definition, the committee used a 1mm x 1mm source (Lambertian, of course) and apodised it to look like Prince Lambert. Then they ran two million rays from the source through a complex optical setup to scramble the rays. Contestants had to create their own optical system such that when the output rays were run backward through it, as many rays as possible would land on the original source as closely as possible to the original position.
To recreate the mystery optical system, contestants could make any optical system they desired, subject to restrictions. To judge the submissions, a figure of merit was published for the problem. The key judging criterion was the power collected on the 1mm2 target when tracing the Prince Lambert rays backward through the contestant’s optical system. The design entry with the most power won.
Dr. Jacobsen was able to create a system in LightTools with about 24% efficiency. His techniques included making a faux GRIN lens, designing the focusing lens in CODE V, managing the complexity with a series of configurations, and aligning the ray bundles. Here is an image of his optical system:
For more details and to see the exact solution that Dr. Jacobsen used, watch the video presentation on our Customer Support Portal (account required). We hope it is enlightening!
Also check out additional topics presented at this year’s LightTools User Group Meeting: