Impact of AI on (specifically) Lens Design?
A couple years back a colleague told me that lens design optimization is essentially AI. At the time, I thought that was a strange comment. But as I’m beginning to educate myself on deep neural networks, I think I see what he meant. DNNs have weights, lens design has variables. They have a loss function; we have a merit function. They’re using gradient descent and finding minima; we’re using damped least squared and finding minima. In some ways they’re analogous.
Our computers are already cranking away with 100% of our hardware resources doing similar math to what’s done with DNNs. For the last 50 years we’ve been attacking lens design with everything our computers can give us. To some extent, we’ve already been doing the type of thing DNNs are doing.
Furthermore, lens design optimization is only going to be successful if you get the merit function right. Every merit function is customized specifically to the present design. One bad or missing operand will render the optimization run useless. I don’t know how you’d train a DNN on merit functions because they’re all unique. Even if they weren’t, I don’t know where you’d find the merit functions to do the training. Also, merit functions evolve over time. At least mine do. They start out rather coarse to get in the ballpark quickly and then expand to refine the design. That only adds to the difficulty of training.
So, I tend to think that AI isn’t going to have the impact on lens design that it is in other places. That isn’t to say there aren’t applications where we’ll use AI. It’s being used to generate starting designs from trained data sets. It’s being applied in niches where DLS might not work that well (e.g., freeform optics). And of course, it’s being used to make the non-design part of our jobs more efficient. But as a tool to get better lenses out of a conventional lens design effort, I’m not seeing it. We aren’t going to give Snell’s law to an unsupervised DNN and have it pop out great new lenses a la AlphaZero.
There’s much more, but this post is already long enough. What do you all think? How is AI going to change lens design?