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Researchers Use Lasers For Cooling
MatthewVD writes "Infrared cameras on satellites and night vision goggles could soon use lasers to cool their components. According to the study published in Nature, researchers in Singapore were able to cool the semiconductor cadmium sulfide from 62 degrees fahrenheit to -9 degrees by focusing a green laser on it and making it fluoresce and lose energy as light. Since they require neither gas nor moving parts, they can be more compact, free from vibration and not prone to mechanical failure."
I seen some cool case mods with glowing lights, now they could actually serve a propose! Neat.
So, shining a green laser into some goggles: what can go wrong?
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Been saying lasers are cool for ages, but do they listen to me? Nooo...
How efficient is this process? Would it be useful as a general replacement for current refrigeration technology?
It would freeze the water around the shark.
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This has been used to cool rubidium to near 0K in labs for a while. Takes some work (the laser needs to be *perfect*), but I've seen the setup myself at a previous employ at a local University.
How is this news? Scientists have been doing this to make BECs FOR AGES.
The laser shines inside onto the back of the sensor.
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The scientists used SI units all the way through in their paper (Kelvin for temperature), and they would have been laughed out of court and certainly not published in Nature if they'd done otherwise.
Why does Slashdot even accept a submission in Fahrenheit when the subject is science? Most nerds understand SI units, and most of the planet is metric. How about trying to be a bit educational for the few that don't? Quote both if you're trying to be helpful, with the SI units as primary for science reporting and imperial equivalents only in brackets.
The primary purpose of Night Vision goggles is to see clearly in the dark in those times where you can't/won't use a torch. So, in times where you may not want to be seen yourself. How is it helpful to have the goggles shine with green laser light to cool them off in this situation?
Presumably the system would be completely self contained. Neither the laser nor the fluorescing being visible. Maybe we can think of the fluorescing as a mechanism to conduct heat from the electronic components to the case of the NVG. Of course that would heat up the NVG case but perhaps it is not emitting in the iR anymore than the person's face underneath it. More info is needed.
It's only the sensor that needs to be cooled below ambient, other parts can use traditional methods. So, you make the back side of the sensor flouresce, capture that light in a chamber where it is converted back to heat, then dissipate that heat through regular air cooled heatsinks.
In the end it's just shifting the heat whilst working against a thermal gradient - same as a refridgerative system, but without moving parts.
In tech circles, english units are the Steampunk of measurements.
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But what cools the laser?
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In Soviet Russia, laser puts in the cooler you!
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I've been looking for new ways to keep my flux capacitor cool.
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Singapore is a tiny island nation, with a tiny population of 4 million citizens (the actually number of people living on that island is 5+ millions, but with close to 2 millions being non-citizens).
I guess congratulations are in order for that tiny nation for funding these type of advance research !
Perhaps t'is another indication of the shift from the West to the East,
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... you make the light sensor more efficient by making it fluoresce?
Um, right. Good luck with that.
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The novel Sundiver by David Brin did this; they used a powerful laser to suck heat out of the Sundiver craft within the atmosphere of the Sun.
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How does this compare with peltier cooling? Is there some obvious reason (e.g. no airflow) why peltier won't work in space?
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Would it be possible to cool CPU chip surfaces by coating them with this glowing material to achieve the same effect?
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Handy for things like uranium isotope separation, and also for creating things like Bosenovas. The problem is, that the process is very sensitive to the frequency of the laser. If these guys have found a way to reliably, inexpensively create the right frequency of light to cool anything...then that substance can act as a heat sink to cool other substance. This could open a whole exciting new era of science and technology. But I won't hold my breathe, the proof is in the pudding, etc.
We have our refrigerator laser, now all we need is a stasis generator, to "control the flow of tune and space through the body of the Sunship, so that the violent tossing of the chromosphere would seem a gentle rocking to those inside." And I'm sure we'll have that any day now.
Yup.
Any.
Day.
Now.
On the other hand, Hollywood prop designers finally feel vindicated.
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Why does Slashdot even accept a submission in Fahrenheit when the subject is science?
Because you can't do car analogies in SI units. It just doesn't work.
Metric is fine for car analogies. Contemporary cars need metric tools, even US domestics.
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Sorry about hijacking this thread, but nobody seems to have posted the temperatures in a proper scale yet, so here we go:
Well, put some of that semiconductor underneath the base plate, aim a 800W laser at it contained inside the device - depending on the speed the material loses heat at, it might be possible to make a "microwave freezer" that freezes (or at least cools) things in seconds.
Probably pie-in-the-sky because of some physical limit (i.e. it might take hours to cool no matter how much power you aim at it), but the "microwave freezer" has been an April Fool "hoax" on at least one BBC science programme (Tomorrow's World) that I fell for when I was younger and would have LOVED to have a device that did that.
If I can heat a meal to burning temperature in minutes, why can't I do the opposite too - reliably, cleanly, reproducibly, without consuming some resource that I would have to keep buying (except electricity, of course).
The applications of a clean "quick-freeze" device run from not just your freezer and fridge, but down to drinks makers, coolboxes, industrial cooling systems, even processor coolers and air-conditioning. I'm actually quite amazed that in this day and age our most common way of cooling things is still the evaporation/condensation cycle of some gas, or blowing air around it. It just seems too primitive in a "quantum" world.
That must be why the mother ship has all those lights. Cooling lasers. The overlords see in the heat spectrum (or not at all) and so never expected us to detect them. Blaart: It's like the huuuman is looking right at ussss. Pleaotard: Not possible, Overlord Blaartumus. We have the cooling lasers working overtime.
Careful on the temperature of that inferno.
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I'm not sure I understand, what is retarded about the units? Has their velocity been reduced?
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1.2% efficient isn't bad for the first go at getting this effect with semiconductors though.
Hell, I bet early solar panels weren't even that efficient, and they are all over the world now.
You would need to get to about 50% efficiency to make them useful, though, but with no-moving parts and all the other advantages, probably even less than that would make them have practical application.
Agreed, having worked with a lab that certifies products sold in the US (21 cfr) and internationally (60825-1 and -2), lasers have gotten more powerful and compact than most folks realize. Class 4 lasers are easily integrated into the handheld green pointers that most of us have seen. What isnt realized is that the 150mw pointers that will blind you like a thief in the night. I have posted blue 445nm and green 532nm lasers to youtube that I have made burning through objects in close proximity, remember these are handheld pointers. Its all about your collimation, and focus on the desired target. These things are dangerous, and used by kids in third world countries for fun. Oh, btw green lasers emit 3 distinct wavelengths, 808 (almost invisible, therby bypassing your blink aversion), 1064nm (same deal), and 532nm which happens to be the peak wavelength for the cones in your eyeball which appears very intense.
I've known more than a few USians who left and went to Singapore because the funding situation is a lot less hassle-- no more proposals to underfunded agencies with low hit rates for small pots of money. Singapore sets them up with a nice lab and stable funding so they can do the things they went into science for in the first place. It doesn't sound bad, but I wouldn't really want to live in Singapore.
Thanks, but we're here for a science lesson, not a history one.
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