[etik]

Great work! Here's some prior art in the (torch) space: https://github.com/vccimaging/DiffOptics

A few notes, though paraxial approximations are "dumb", they are very useful tools for lens designers and understanding/constraining the design space - calculating the F/#, aperture stop, principal planes and is critical in some approaches. This pushes what autodiff tools are capable of because you need to get Hessians of your surface. There's also a rich history in objective function definition and quadrature integration techniques thereof which you can work to implement, and you may like to have users be able to specify explicit parametric constraints.

[fouronnes3]

Yes, that DiffOptics paper was one of my main inspiration for this project. It's a very cool paper.

> There's also a rich history in objective function definition and quadrature integration techniques thereof which you can work to implement, and you may like to have users be able to specify explicit parametric constraints.

Yes, this is definitely the direction I want to take the project in. If you have any reference material to share I'd be interested!

[etik]

Gaussian quadrature integration for rms spot size or wavefront error:

> Forbes, G. W. (1989). Optical system assessment for design: numerical ray tracing in the Gaussian pupil. Journal of the Optical Society of America A, 6(8), 1123. https://doi.org/10.1364/josaa.6.001123

In general, you'll want to look at MTF calculation (look at Zemax's manual for explanation/how-to). There is also a technique to target optimization at particular spatial frequencies:

> K. E. Moore, E. Elliott, et. al. "Digital Contrast Optimization - A faster and better method for optimizing system MTF," in Optical Design and Fabrication 2017 (Freeform, IODC, OFT), OSA Technical Digest (online) (Optical Society of America, 2017), paper IW1A.3

[barrenko]

A big question here, do you think it would be possible to self-study optics and what would it take?