Colour-changing magnifying glass gives clear view of infrared light

https://www.cam.ac.uk/research/news/colour-changing-magnifying-glass-gives-clear-view-of-infrared-light

by rustoo • 5 years ago

145 48 5 years ago

cam.ac.uk

edrxty2• 5 years ago

This will almost certainly be used for weapons in short order.

Currently if you want thermal imaging or very low light capability you have to use very expensive substrates. Being able to use CMOS detectors for MWIR/LWIR would instantly increase available resolutions by an order of magnitude at any given price point, assuming these filters are actually relatively cheap.

CamperBob22• 5 years ago

Yep, if it works at all, ITAR will slap it with a "Don't even think about using this for anything" label.

toss12• 5 years ago

No, if they slap a label on it, it isn't "Don't Use It", it is "Don't even think about exporting this without permission.". It may have been relaxed, but regular IR cameras that we can buy and use here everyday in the US may land you in jail for selling them in eBay and shipping them to a customer in China or Iran. But we can buy, sell, and use them freely.

nine_k• 5 years ago

Anything and everything will be used for weapons. All, from nuclear reactions ultrafast computers to water pipes and sugar.

The problem with weapons is not that science and technology allow more and more. Say, Pol Pot's regime, or the Rwanda genocide, have shown that large-scale atrocities can be perpetrated using very low-tech means.

withinboredom2• 5 years ago

I doubt it. It sounds like it has to be “charged” with visible light or something. That means it’s unlikely to be useful some time after sundown, or after being used. I don’t see a military springing for that because it would put constraints on the types of operations they can run unless it adds significant upsides (such as an increase in FOV or something). I do see it being more useful for civilians though, who don’t need them at any random point of the night.

hoseja• 5 years ago

I think you can just back(front?)light it.

downrightmike• 5 years ago

The charge seems to be using gold's excellent ability to reflect, to concentrate all wave lengths onto a molecule that will then produce visible light.

nullc• 5 years ago

If I'm not misunderstanding the paper this shows extremely low quantum efficiencies-- doesn't sound like it would be useful without massive increases in QE.

jcims• 5 years ago

Reminds me of this experiment from Ben Krasnow using thermal paint - https://www.youtube.com/watch?v=qgS0hTKBLXM

philprx2• 5 years ago

Years ago I stumbled upon something related: it was a piece of transparent polymer or polycarbonate that would glow when exposed to infrared light.

I tried to find it again repeatedly, but never managed to find it. Anyone knows this?

filmor• 5 years ago

Do you mean something like this http://www.bromba.com/indicard/indicare.htm? I remember that we used this in experiments with IR lasers to ensure that the beam was where we expected it to be.

sound1• 5 years ago

Reminds me of Enchroma glasses for the colorblind: https://youtu.be/hqHlIRZnF38

tgsovlerkhgsel• 5 years ago

So, is this something that can actually make infrared light visible, or a coating that can be applied directly to sensors?

(I suspect the headline is simply clickbait/a lie, just like most university press releases.)

tinus_hn2• 5 years ago

Not unimaginable, a similar coating is on the inside of fluorescent lighting tubes.

jeffwass• 5 years ago

Not really, the coating on fluorescent tubes uses a quite different mechanism.

The phosphor coating of fluorescent tubes downconverts UV light into visible wavelengths (is, lower energy/frequency) through the process of fluorescence. The UV photons excite the electrons of the phosphor molecules to higher energy states, after which they emit photons at lower frequencies/energies (visible light) as they fluoresce back to the ground state.

In this case however, the IR to visible light conversion actually increases the energy and frequency of emitted photons.

Total energy must be conserved, so extra energy is incorporated in some way for the upconversion.

There was a plastic film material I saw a few decades ago that lights up when you shine infrared light on it, which was useful for testing IR transmitters and receivers. IIRC, that material only worked when it was bathed in visible light for some time prior to use, where the absorbed visible light acted as an energy bath to provide the required energy for the photon upconversion.

krkoch• 5 years ago

Does this glass need a power supply, or do two ir photons join to make a visible photon? A reverse of scintillation?

bowejg• 5 years ago

It's using upconversion so it's 'powered' by the shorter wavelength light shining onto it

AnthonBerg• 5 years ago

Cool!

Here's the DOI.org link to the paper for other readers’ convenience – the article only has the DOI code: https://doi.org/10.1126/science.abk2593

tabokie• 5 years ago

I've always wanted glasses that can convert color to grey-scale. Wear them and walk into a black-and-white movie.

jayd16• 5 years ago

You could use Oculus Quest passthrough video, I suppose. Grayscale alone doesn't give you a black and white movie feel, though.

drewm1980• 5 years ago

For additional context about the lead:

https://www.cei.washington.edu/education/science-of-solar/pe...

"while the best-performing perovskites are today made with a small amount of lead, researchers are also exploring alternative compositions and new encapsulation strategies, in order to mitigate concerns associated with lead toxicity."

londons_explore• 5 years ago

Why do scientists who seem to select gold as the ideal material for almost anything?

Is it actually a better material, or do scientists just want to be able to put in a purchase order for some gold and have shiny photos on all the media reports?

Yes, I know it has a low reactivity - but stainless steel is pretty good there too, as well as a bunch of other materials. It also has a high conductivity - but copper is pretty decent.

dtgriscom• 5 years ago

Stainless steel isn't an element, it's an alloy. You (probably?) can't plate stainless steel onto a surface.

ChrisMarshallNY• 5 years ago

Gold is an awesome conductor, and, more importantly, it is nearly impervious to corrosion.

That’s why it’s used in circuit board solder points and various types of plugs.

I think that platinum may be slightly better, but it is even more expensive.

Gold electroplating is not for the faint of heart. They use cyanide as a catalyst. At one of the companies I worked for, they had 50-gallon drums of cyanide, down in the electroplating lab.

Karliss• 5 years ago

Stainless steel still corrodes under harsh conditions.

One of the mechanisms for why stainless steel is has low reactivity is through passivation. The elements mixed into stainless steel alloy quickly form a thin oxide layer in normal atmosphere which prevents further corrosion similar to aluminum or titanium. That's good enough for structural use but not the same as actually chemically inert elements.

There is also aspect of what happens in more conditions like being pulverized to the nanoparticle size or vaporized and deposited at few atom thin layer.

Silver and copper actually have better thermal and electric conductivity than gold, but they don't have the other good properties gold has.

Also it's at the bottom of periodic table (usable part) which might be important for certain interactions and correlates with extremes of multiple properties. There is one more row lower, but most of those elements are radioactive, not occurring naturally or both, which eliminates almost any practical use, complicates research and introduces new weird properties.

the__alchemist2• 5 years ago

Article link https://www.researchgate.net/publication/356757012_Detecting...

(Click "Download full text PDF")

the__alchemist2• 5 years ago

Question re this: > Although the development of mid-IR (MIR) sources is evolving, a bottleneck con- tinues to be producing low-noise room tem-perature detectors

How do these relate to the relatively cheap IR cameras available? Eg, both commercial IR cameras, and military NVGs work at room temperature (Using different technologies). For example, are the devices lamented about in the article high-precision scientific instrument that can detect very fine differences in freq?

edit: This may be the key: > The noise-equivalent power of hybrid nanocavity- molecular detectors is predicted to be 100-fold lower than commercial uncooled detectors.

marcodiego• 5 years ago

Why not show a single image of the device in use?

leephillips• 5 years ago

Current browsers don’t support infrared images.

zbyforgotpass• 5 years ago

The "magnifying" part of this is probably just a red herring - in the article itself there is nothing about the magnifying effect.

Colour-changing magnifying glass gives clear view of infrared light

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