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This article describes how nano metalenses work and what they can be used for. Spoiler alert: they can't be used to replace your smartphone's camera lenses yet, but can be used for IR distance sensors used on drones and soon, polarization sensors that will be able to tell materials apart and even detect cracks in concrete.
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Therre's a diagram in TFA, comparing the construction of a conventional lens with a metalens. The diagram shows two labelled parts that I didn't understand: a) Glass plate with bandpass filter b) Near-infrared contact image sensor The legend doesn't say, but I suspect the diagrams show a distance sensor, not a camera. So I assume the infrared lasers have been omitted from the diagram. Also, I'd quite like to know a b…
Contact image sensors are image sensors designed to be slapped right up against something. They're used in scanners and surface inspection sensors. No clue how this relates to meta-lenses.
I suspect it's just a bad diagram. Their barrel design is impossible to manufacture.
Source: Optical engineer.
https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=10...
Thin, frenzel-free VR goggles in the future then?
Seems like one of the obvious applications. I wonder why it isn't mentioned. Is there a technical limitation that make it impractical? Size maybe, the lens shown in the article are all tiny and I guess lens that would be practical for AR/VR would be really expensive.
Yes. Diffractive optics (which includes meta-lenses) have significant wavelength dependence. Visible light is 400-700nm, which are different by about a factor of 2. This means blue light will focus almost twice as far away as red light does.
The neat bit is this is actually the reverse of how refractive optics behave, which means you can use both together and cancel out a significant portion of chromatic aberration. If we can scale up the manufacturing (and ideally apply them to curved surfaces) they could improve performance and reduce complexity and weight of VR/AR optics.
Earlier quoted context omitted.
AI-equipped cars with a real sense of feeling in their tires. It’ll be like the sensation of touch for them. Everything they run over, they will feel. Make them learn that animals feel gross to touch. Make them feel remorse for running over a human. Boom! Self-driving safety solved!
This opens the door to kinky AI
Therre's a diagram in TFA, comparing the construction of a conventional lens with a metalens. The diagram shows two labelled parts that I didn't understand: a) Glass plate with bandpass filter b) Near-infrared contact image sensor The legend doesn't say, but I suspect the diagrams show a distance sensor, not a camera. So I assume the infrared lasers have been omitted from the diagram. Also, I'd quite like to know a b…
Optical bandpass filters are used to fine-tune the bandwidth of the sensor, as most sensors actually have pretty wide bandwidths. Typical silicon sensors have sensitivity extending well into the IR, which can confuse people when their pictures show lights they can't see. This can totally be made using something like the dark-red filter on the TV remote (reversed, it'd block red so appear blue), but fancier ones will…
Yup, since the optic is planar it can integrate with backend coating processes
> Contact image sensors ... No clue how this relates to meta-lenses.
I'm also not sure how "contact" got into the copy
> I suspect it's just a bad diagram. Their barrel design is impossible to manufacture.
Yea, the barrels end up looking like more traditional barrels
Source: Metalenz CTO
Earlier quoted context omitted.
Optical bandpass filters are used to fine-tune the bandwidth of the sensor, as most sensors actually have pretty wide bandwidths. Typical silicon sensors have sensitivity extending well into the IR, which can confuse people when their pictures show lights they can't see. This can totally be made using something like the dark-red filter on the TV remote (reversed, it'd block red so appear blue), but fancier ones will…
> They may use absorbing substrate, or may add a backside coating. Yup, since the optic is planar it can integrate with backend coating processes > Contact image sensors ... No clue how this relates to meta-lenses. I'm also not sure how "contact" got into the copy > I suspect it's just a bad diagram. Their barrel design is impossible to manufacture. Yea, the barrels end up looking like more traditional barrels Source…
The process starts by illuminating a scene with a monochromatic light source—a
laser.
So it's not gonna work for standard glasses, current VR or anything else like that.
This article describes how nano metalenses work and what they can be used for. Spoiler alert: they can't be used to replace your smartphone's camera lenses yet, but can be used for IR distance sensors used on drones and soon, polarization sensors that will be able to tell materials apart and even detect cracks in concrete.
Speaking of Fresnel lenses, one of the coolest applications is a plastic "wide-angle lens" sticker that you could affix to your car's rear window ( https://www.amazon.de/-/en/WIDE-ANGLE-WINDOW-FRESNEL-OPTICAL... ) to increase the field of view. Their popularity has dropped since the advent of "back-up cameras" however.