Talk:Laser cooling

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[edit] Mechanism needs clarification

We currently have this:

Because the light is detuned to the "red" (i.e. at lower frequency) of the transition, the atoms will absorb more photons if they move towards the light source, due to the Doppler effect. Thus if one applies light from two opposite directions, the atoms will always scatter more photons from the laser beam pointing opposite to their direction of motion.

I don't think this is clear enough. The word "thus" joins a sentence about absorbtion with a conclusion about scattering, with no explanation of how the two are related. I don't know enough about the topic to fix this. --P3d0 13:25, Jun 24, 2005 (UTC)

I agree. I think a much easier-to-understand explanation is possible. ... Hmmm, that ended up being *much* longer than I expected. Feel free to condense it down and post to the article. --DavidCary 12:46, 26 July 2005 (UTC)

OK, I put my rough draft into the article. --DavidCary 00:14, 1 December 2005 (UTC)

the Laser Teaching Center at Stony Brook University http://laser.physics.sunysb.edu/projects/ seems to show a lot of people working with "Laser cooling", and with related ideas such as "MOT's" (magneto-optical traps), "Optical tweezers", etc. Should we ask nicely for some photos?

Overall, I think this article is very successful in explaining the basic concepts of laser cooling. I'd like to make a few more minor edits when I have time, especially on the history of the subject, which is subject to a surprising amount of misinformation. Dave Kielpinski 06:08, 18 December 2005 (UTC)

[edit] Old request for information

I apologize for the delay responding; I'd missed the original request, then gotten extremely busy. If any of the information in the laser cooling thread in my talk page archives is useful, by all means use it. --Christopher Thomas 03:54, 8 January 2006 (UTC)

[edit] question

How effective is laser cooling? does it cool fast? can it only cool to ex. 0 celcius, or can it cool to minus degrees too? Are there any real implementations? how much would such a cooling cost? how big would such a cooling device be? Imagine cooling your computer with that. ;) —The preceding unsigned comment was added by Frap (talk • contribs) on 21:13, 20 May 2006.

First please use four ~ (~~~~) marks to automatically insert a signature with datestamp after your talk-page comments.
Secondly several of your questions are already answered in the article. It cools far below 0 degrees centigrade. Target temperatures are millikelvin or lower (lowest I'd heard cited was nanokelvin). These cooling systems are in widespread use in physics laboratories for studying things like Bose-Einstein condensates.
The cooling systems are fairly cheap as far as laboratory systems go, costing several thousand dollars to a few tens of thousands. I don't have information on rate of cooling, but I imagine it would be quite slow (you're using light pressure to bleed off kinetic energy of molecules, _and_ it's only a statistical average effect, _and_ absorption rate difference will drop as the molecules slow down, slowing cooling). The devices range from the size of a computer monitor on up (they're vacuum chambers with lasers shining into them and usually magnetic field coils around them, generally small enough to bolt to a lab bench).
This would be useless for cooling a computer. What you need to do when cooling a computer is to keep the outer surface of the chip module (or die, for chips mounted with the bare die exposed) as cool as possible. The active parts of the silicon will still be at 50-100 degrees centigrade; you're just using a larger heat difference to the outer surface of the chip to increase the rate at which heat flows out of the system. This takes a system with high throughput, but doesn't require absolute temperatures anywhere near this low. See overclocking for more information.
--Christopher Thomas 23:37, 20 May 2006 (UTC)
Just to add this article is very simliar to doppler cooling, as indeed it is the same process being used. There is no mention of the optical molasses technique which utilises 3 pairs of lasers doing this process (and subsequently the magneto-optical trap which uses the this and oppositely directed magnetic fields).
Lastly there is also the application of atomic lasers... —Preceding unsigned comment added by 131.227.231.210 (talk) 19:06, 9 December 2007 (UTC)

[edit] No mention of laser cooling of solids

The first experimental demonstration of laser cooling in solids (Yb-doped glass) took place in 1995 at Los Alamos National Labs by Epstein et al. Published in Nature, 1995.64.106.62.179 18:25, 4 September 2007 (UTC)

There is no mention of laser cooling of solids in this article. The first instance I'm aware of this happening was published in: Phys. Rev. Lett. 78,1030 - 1033 (1997)

Since this kind of laser cooling uses an entirely different mechanism (that of anti-stokes fluorescence, should it be made into a separate article?

I agree that anti-stokes cooling deserves an article (I was looking for a Wiki link for that) - whether it should be part of the atomic version of "laser cooling" or put on a separate page with a disambiguation is unclear. Probably depends on how much gets written. Tarchon 01:12, 26 April 2007 (UTC)

Since laser cooling of solids is also called "laser cooling", what should we call the page that talks about cooling of solids? Ebudiu 02:28, 29 May 2007 (UTC)

I think "optical cooling" would be the higher level topic which would subsume the various laser cooling techniques and other non-laser optical cooling approaches. I would also leave out "of solids" as being unnecessarily restrictive. The basic process of using thermal-photonic interactions to cool doesn't have any inherent restriction to solids to my knowledge.Tarchon 00:30, 26 October 2007 (UTC)

[edit] Historical factual errors

The article says that laser cooling was first demonstrated by Letokhov, Minogin and Pavlik. What is ment by "demonstrated" here? The first experiments that utilized these ideas are experiments performed by Wineland, Drullinger and Walls in 1978 who cooled Mg ions and the same year Neuhauser, Hohenstatt, Toschek and Dehmelt cooled Ba ions. I would think the original poster is talking about this article by Letokov et al but that is a theoretical thesis and doesn't contain any experimental data. The other two papers are here and here. --ojs (talk) 13:44, 20 November 2007 (UTC)