Re:Zoomable lens without any moving parts
by cycomanic on Saturday April 03, 2021 @02:03AM
(#26678720)
That's incorrect, metalenses are not diffractive lenses. They continuisly change the local refractive index through subwavelength structures. There's a brief introduction and discussion about differences with diffractive lenses here: https://www.nature.com/articles/s41467-020-15972-9
Re:Zoomable lens without any moving parts
by amelius on Saturday April 03, 2021 @10:09AM
(#26681172)
Why is "meta" in the name?
Re:Zoomable lens without any moving parts
by jasonwatkinspdx on Saturday April 03, 2021 @11:57AM
(#26682037)
It's a general category of assemblies / structures that mimic a material with unusual or even impossible properties: https://en.wikipedia.org/wiki/Metamaterial
Re:Zoomable lens without any moving parts
by mrdrrobots on Saturday April 03, 2021 @12:20PM
(#26682234)
Co-author here, Not a binary zone plate.
Re:Zoomable lens without any moving parts
by mikewarot on Saturday April 03, 2021 @01:18PM
(#26682800)
How wide of a bandwidth could this handle? Do you think it will be possible to cover the entire visible light spectrum some day?
Re:Zoomable lens without any moving parts
by mrdrrobots on Saturday April 03, 2021 @02:13PM
(#26683288)
It’s theoretically possible; this is a very active field of research.
The images shown lead me to suspect this is a binary zone plate, which has a much narrower bandwidth over which it would be effective.
However, this is all prototypes, if they can indeed make a zone plate that can be addressed as pixels, with finer control over phase shift at each pixel, there are quite a few places where it would be quite useful, in spite of the narrower bandwidth.
https://en.wikipedia.org/wiki/Zone_plate