Flat focusable lens - no, not fresnel

Did anybody else catch this the other day?

[h=1]Flat lens promises possible revolution in optics[/h]
http://www.bbc.com/news/science-environment-36438686

Now that would indeed be a game-changer - imagine being able to control the wavelength &/or focus of the beam from your torch without using a curved lens. (Ignoring the more mundane applications touched on in the article).

Something about that website wasn't playing well with my 'puter so I couldn't watch the video. Looks very promising and some of it went over my head but is it focusable after it's made? My take is that any focal length could be made by changing the programming prior to manufacture.

Bookmarked this thread; should be a good discussion.

Dan

No, I think you are correct, I read it the same way in that you have to fabricate it to suit the desired focal length, at least at this stage.

I don't think it is in the realm of fantasy though to have something akin to an LCD where you can rearrange the nano-pillars to go say, from infinite focal length (i.e. zoom) to flood.

The nature of these articles is that they are a bit of a tease, and do not have all the detail, but the concept just seems to have some huge potential. For a flashlight, an infinitely-variable zoom along with the ability to specify the wavelength or spectral composition ticks my boxes.

If feasible, and I don't see why not, it would be interesting to develop spectacles that converted UV or IR into the visible spectrum. Not sure what the practical applications are though, off the top of my head.

Looks promising. The flatness of a fresnel lens with much better beam quality.

For a flashlight I do wonder how durable those microscopic crystals would be though. If you accidentally rub the lens with your finger would they all break off?

as a trained and licensed optician I can say with lots of experience that even when mass production tooling is designed and built these lenses no matter what size they are no matter how weak or strong a prescription they are to fill they will cost a fortune. I am talking $1500 per lens for a pair of Rx lenses. Then there is Transition lenses add transitions to this tech then of course the worlds likely most expensive anti glare coating(yes even on a nano scale of correction there will still be glare without a coating)and you have a $4,000 pair of lenses. This technology is likely straddling both black classified projects and white civilian research at the same time. Dont count on this tech showing up in any kind of flashlight...ever.

Modern day Rx lens tech is extremely good. Super high index lens materials for strong prescriptions so they still come out aesthetically pleasing and not coke bottle lenses. Glare coating tech is on a whole different planet now. It is expensive but worth it. There is a green(dark green)transitions lens now on and on. This tech is likely already in use by western military. Armytek still has the highest quality optics and glare coat in the entire industry and I do not see that changing for a good while.

Hi CelticCross - I think we are seeing this from different perspectives - I hadn't even considered applications for optical prescription lenses, indeed I had to look up what Rx meant! I agree with you from what I have seen over the past few years in terms of progress of materials and design but I was more interested in other potential applications.

I was coming more from the idea of being able to apply a layer of these microscopic objects across a flashlight lens, which would allow you to better control focus from flood to zoom.

In fact having had a slight eureka moment, I don't see why you couldn't deposit them across the surface of the LED itself, doing away with the need for a reflector or TIR, or aspheric lens, altogether. That would open a whole new world of possibilities, you could have a really small form factor like say a signet ring which could have a LED where all the lumens were focussed as a hotspot 200 yards away. At the tint or wavelength of your choice. Heat might be a problem, but there wouldn't be the need for a large reflector which could give rise to some interesting designs.

I personally believe LED technology is nowhere near its peak. What will come over the next 10 years from Cree etc. will seem like the stuff of science fiction. I predict an LED with a chemical makeup that allows it to change its tint color into RGB via micro managing current. No more secondary colored LEDs one will do 4 or 5 tints or colors. As for applying this new tech to an LED sure I can see it and actually that would be kind of likely as the surface area covered would be so small it would be economically viable to do. As for the lens itself it will always be there and should be there to protect the LED and reflector if there is one.