I think of it as the output being the solution of an equation/dynamic system. It's ok you lose the equations, you care about the solution. I've been doing some light internet research into this not too long ago and came across this title https://www.amazon.com/Neuromorphic-Photonics-Paul-R-Prucnal... that seems to suggest that analog photonics might be the way forward.
But I can't really comment on the state of this. Photonics is definitely becoming more and more viable it appears.
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