Researchers develop flat lens a thousand times thinner than a human hair:
A lens that is a thousand times thinner than a human hair has been developed in Brazil by researchers at the University of São Paulo's São Carlos School of Engineering (EESC-USP). It can serve as a camera lens in smartphones or be used in other devices that depend on sensors.
[...] The lens consists of a single nanometric layer of silicon on arrays of nanoposts that interact with light. The structure is printed by photolithography, a well-known technique used to fabricate transistors.
This kind of lens is known as a metalens.
[...] "Our lens has an arbitrary field of view, which ideally can reach 180° without image distortion," Rezende Martins said. "We've tested its effectiveness for an angle of 110°. With wider angles of view, light energy decreases owing to the shadow effect, but this can be corrected by post-processing."
Previously metalenses have been limited in their field of view. This lens opens up a much wider range of possibilities.
Journal Reference:
Augusto Martins, et. al.,On Metalenses with Arbitrarily Wide Field of View, ACS Photonics (DOI: 10.1021/acsphotonics.0c00479)
(Score: 0) by Anonymous Coward on Wednesday August 26 2020, @03:03PM
Researchers Make Hair a Thousand Times Thinner.
It's a no-win situation. The only effective strategy is to not play.
(Score: 2) by bzipitidoo on Wednesday August 26 2020, @03:03PM (6 children)
So is this a Fresnel lens with the breaks invisibly microscopic? Fresnals are kinda neat, but I never did care for all the circles it superimposes on the view.
(Score: 0) by Anonymous Coward on Wednesday August 26 2020, @03:42PM
Both are "flat", but otherwise not the same. These new things have elements that are on the same order as the wavelength of light. Fresnel lens elements are >> light wavelength.
(Score: 4, Informative) by richtopia on Wednesday August 26 2020, @03:50PM (3 children)
Actually it is a meta lens. I had to look that up myself: https://phys.org/news/2020-08-lens-world-metalens-liquid-crystal.html [phys.org]
My understanding is the lens can be modified by an energy source (manipulated thermally, electrically, magnetically or optically), allowing a programmable lens.
Particularly for a mobile phone that could be a game changer: a small footprint which can cover both wide angle down to potentially telephoto. It could remove the requirement for phones to have multiple cameras with different lenses.
(Score: 0) by Anonymous Coward on Wednesday August 26 2020, @04:54PM (1 child)
And this helps improve porn how?
(Score: 1, Insightful) by Anonymous Coward on Wednesday August 26 2020, @05:38PM
> And this helps improve pron how?
Well, upskirts will be color corrected and in focus, no matter where the new and much smaller camera is located...of course they are still just ethically-challenged (and illegal) as ever.
(Score: 0) by Anonymous Coward on Wednesday August 26 2020, @06:28PM
Unless there is some great breakthrough here, the problem with metalenses of any kind, whether it be for making flat optics or "cloaking" devices, is that they essentially only work at a single wavelength. Other wavelengths don't interact the same way as the one it was tuned for, so it is always "some day" that these "can be used in a cell phone". That step between now and "some day" has been very large.
(Score: 2) by crafoo on Thursday August 27 2020, @07:56PM
No, I don't think so. I believe it's using structures on the order of size of wavelength of visible light, making them diffractive and not refractive lenses (Fresnel lenses).
This quote from the summary annoyed me a little, "We've tested its effectiveness for an angle of 110°. With wider angles of view, light energy decreases owing to the shadow effect, but this can be corrected by post-processing."
Just say it has an effective FoV of 110deg. Obviously post-processing cannot compensate for lack of light, or at least significantly reduces your options as you will have to blast the scene with an absurd amount of light.
(Score: 2, Informative) by Anonymous Coward on Wednesday August 26 2020, @03:38PM (1 child)
https://cns1.rc.fas.harvard.edu/single-metalens-focuses-entire-visible-spectrum-light-one-point/ [harvard.edu]
Harvard has one of these metalenses too. This one claims it solves prior problems of chromatic aberration, so it's "color corrected".
(Score: 2) by VLM on Wednesday August 26 2020, @05:47PM
Yeah I saw that too. I googled around trying to find AI deep-fake style automated chromatic aberration correction, didn't find much.
In the long run I think it'll be cheaper and faster to fix it in post using a CPU rather than trying to make truly aberration free lenses.
This applies to microscopes too. Eventually I bet the only aberration free optics will be photon limited stuff like astronomy telescopes. Everything else will just use software to fix everything.
I'd bet money on this if I knew where to invest the money. Glass optics is dead, the "fancy" expensive stuff is all going away. Just use a shit cheap lens with special AI cleaning up the captured image.
Why put hundreds of dollars into a microscope Plan Apochromat or even cheap flourite objective if you can replace hundreds of dollars of engineered glass with 50 cents of CPU and software?
Heck why bother correcting field curvature if you have the focus knob on a servo and enough CPU memory and AI to photo-merge it all together?
The idea of looking thru a microscope like the old days will be quaint when modern scope users just put on the VR Goggles instead.
(Score: 2) by Nuke on Wednesday August 26 2020, @07:15PM (3 children)
Can someone explain to me, preferably in words of one syllable, what the advantage is to a smartphone of the lens being 1/1000 the thicckness of a human hair. Sounds a bit fragile to me.
(Score: 2) by acid andy on Wednesday August 26 2020, @07:36PM
Less raw material is needed to make it (maybe photolithography adds more overheads though; I don't know) and it builds in potentially quicker obsolescence, so it's a win-win. Oh, and they can boast how their new iPhone is even thinner than a piece of toilet paper so you simply must upgrade to get rid of that laughable old thick wedge of a phone you got there.
No fuc|<s given.
(Score: 2) by HiThere on Wednesday August 26 2020, @07:50PM
If you make it thin enough, you use it by plating it on something else. So the lens itself isn't fragile, merely the glass you plate it onto.
Otherwise, really thin stuff can be bent at weird angles without damage. The way that it's damaged is by ripples or tears. So it might be fragile to swiping a finger across, but not to being bent. So you sandwich it between two sheets of plastic with the desired properties, or even glass. Since this is a "programmable lens" you're going to want to connect a bunch of controls to it...but I'm not sure what kind of control. Possibly magnetic or electric fields, or even some frequency of em radiation. You probably wouldn't be using visible light for that, though.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.
(Score: 0) by Anonymous Coward on Wednesday August 26 2020, @08:57PM
lighter VR headgear
(Score: 1) by HammeredGlass on Wednesday August 26 2020, @11:21PM (2 children)
I would like to get contact lenses like this that rarely have to be removed if they could allow more oxygen to reach the eye.
(Score: 0) by Anonymous Coward on Thursday August 27 2020, @02:13AM (1 child)
The drawings I've seen show these metalenses as a field of little prisms (or more likely antennas--at the lengths of light wavelengths). There wasn't any obvious reason why the active elements need to be stuck to a solid substrate. Perhaps they can be attached together by something more like a screen to make them porous for contact lenses.
It's good to be alive, the solutions to a wide variety of medical problems are coming faster and faster these days.
(Score: 2) by Bot on Thursday August 27 2020, @02:10PM
> the solutions to a wide variety of medical problems are coming faster and faster these days
thanks also to the bill and melinda gates foundation. What can possibly go wrong.
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