How do cold lasers work?

[derekmohammed]

Cold Lasers?

Hi,
I was overheard one of my profs talking and he was talking about cold lasers. I googled it but I could not find anything worth while. Does the laser "slow" down the electrons in the obitals? I don't really know how to approach this one... Does anyone know anything about this?

Derek

 

[LURCH]

http://www.colorado.edu/physics/2000/bec/index.html may seem a little bit "Dick and Jane", but it contains fairly straightforward information. At the bottom of the page there is a link to a "laser cooling" page. The main jist of the laser's usefulness is that Adams will only be affected by a laser at a very particular frequency. The exact frequency depends on the type of atom.

The other main factor is red shift. Because of the red shift, the motion of an individual atom determines what color it "sees" from the laser.

 

[Laser Jock]

Hi,
I was overheard one of my profs talking and he was talking about cold lasers. I googled it but I could not find anything worth while. Does the laser "slow" down the electrons in the obitals? I don't really know how to approach this one... Does anyone know anything about this?

Derek

Cold lasers? The prof may have been talking about laser cooling (see Lurch's link). You can use lasers to slow down the velocity (and thereby lower the temperature) of atoms. You cannot slow down electrons in their orbitals. Now maybe the prof didn't want their laser to get too warm (like they had the water cooling system shut down or something), otherwise a "cold" laser doesn't make much sense.

 

[DaveC426913]

Sure. Your prof is up on the latest in eye surgery. You know, those eye surgery commercials on the radio are always talking about "cool blue waves of laser light washing gently over your eye".

(You don't suppose they're going to say "a pinpoint of focussed laser light will vapourize the surface tissues of your eyeball - just ignore that crackling sound and the wisps of smoke" now are they?)

 

[HallsofIvy]

Back when I was young, lasers required an entire room for one laser and could drill holes in steel- that's a "hot" laser!

Now, you can go to the hardware store and buy a laser that you then use to set up horizontal lines on your walls- that is certainly what I would mean by a "cold laser"!

 

[NoTime]

Perhaps they were talking about Bose-Einstein condensate (atom lasers).

 

[Gonzolo]

Ophtalmologists seem to use the term "cold laser" for lasers that do very localized tissu damage such that the procedure can be repeated indefinitely in the future. They cause minimal "co-lateral damage". Wavelengths seem to be in the UV and visible range. I think it is to be seen as "cold lasers" vs "IR lasers". Using "visible" or "UV" might scare away patients. Excimers and f-doubled Nd:YAG seem to be considered as cold lasers in this context.