Bounds for the best possible designs for optical devices: well-studied [0, 1, 2, 3, 4], yet really hard. More specifically, whenever you give a designer a desi

Bounds for the best possible designs for optical devices: well-studied [0, 1, 2, 3, 4], yet really hard. More specifically, whenever you give a designer a design spec, it is always worth asking, how good is the best possible design for this spec? And, of course, can the designer actually achieve it, or something close to it? This is the question here. In this scenario, the design spec is the optimization problem (what you want to optimize), the designer then gets to choose how to best approach this problem. In this case, you want to give a number that states, independent of how this problem is solved, what is the best any designer (no matter how smart or sophisticated, how much computational power they have, etc) can hope to do. In many cases giving such a number is actually possible! (See below references.) ----- [0] https://pubs.acs.org/doi/10.1021/acsphotonics.9b00154 https://pubs.acs.org/doi/10.1021/acsphotonics.9b00154 (PDF: http://web.stanford.edu/~boyd/papers/pdf/comp_imposs_res.pdf http://web.stanford.edu/~boyd/papers/pdf/comp_imposs_res.pdf) [1] https://arxiv.org/abs/2002.00521 https://arxiv.org/abs/2002.00521 [2] https://arxiv.org/abs/2003.00374 https://arxiv.org/abs/2003.00374 [3] https://arxiv.org/abs/2002.05644 https://arxiv.org/abs/2002.05644 [4] https://arxiv.org/abs/2001.11531 https://arxiv.org/abs/2001.11531