Anton Petrov:
https://www.youtube.com/watch?v=wQh9ezBdoPM
Also cross-posted from: https://programming.dev/post/31467824
A team of physicists at ETH Zurich has created a tiny metalens that can half the wavelength of incident light.
They have achieved this using a special metal-oxide lens material called lithium niobate and through nanoscale pattern, stamped into the material.
Such metalenses could be used as a security feature on banknotes or in the fabrication of ultra-thin elements for cameras.
I don't know for sure, but I watched an interview that Fraser Cain posted with Lucas Norder from "Breakthrough Star Shot", (the private mission to send a probe to the nearest star Alpha Centauri using lasers and solar sails). In that interview they were talking about a similar technology where the material is ablated to filter the laser frequency of light. I think this is basically the same/similar thing. I'm sure there are some tradeoffs. Anton talks about it not being very clear or usefully in visual focus IIRC. I picture it evolving into something like the FPS video game hack where players of something like Counter Strike can see the outline of other players through walls and such, but obviously to a much lesser extent and not through most obstructions. For instance, it would only take a small percentage of extra visual IR hinting to be super useful in a forest or jungle like environment against an enemy. Seeing the person glow would not be the point. Just a small amount of extra contrast would be a major advantage that works with existing instincts and intuition.