Revolutionary Cooling System Uses Lasers

[n2doc]

Jan. 30, 2013 — With the latest discovery by scientists from Nanyang Technological University (NTU), current cooling systems which uses refrigerant harmful to the ozone layer could be replaced by a revolutionary cooling system using lasers.

This discovery, published and featured on the cover of the 24 January 2013 issue of Nature, could also potentially lead to a host of other innovations. This includes making huge Magnetic Resonance Imaging (MRI) machines, unwieldy night vision goggles and satellite cameras -- all of which require extreme cooling systems -- even more compact and energy saving.

This breakthrough in laser cooling technology can even lead to the development of almost sci-fi like computer chips that cool on their own, minimising heat and thus prolonging battery life for portable devices like tablets and smart phones.

Assistant Professor Xiong Qihua from the School of Physical and Mathematical Sciences and the School of Electrical and Electronic Engineering had cooled down a semiconductor from 20 degrees Celsius down to minus 20 degrees Celsius. Before this, the cooling of semiconductors by laser has never been proven.

more

http://www.sciencedaily.com/releases/2013/01/130130101932.htm

It's unclear where the heat goes, or how energy efficient this is, but if it can be put on a chip, then it could really change some tech areas.

[phantom power]

1. heat goes into the laser beam

[eppur_se_muova]

2. Heat goes into the laser beam, which has to go somewhere -- probably to another method of cooling.

This is more likely to be useful for pumping heat out of the immediate area where it is produced, rather than from the total working environment. Imagine running a high-irradiance laser to cool a single chip -- the laser beam must be absorbed somehow, and the heat from that dissipated, while the heat from the laser itself poses an even bigger cooling problem (lasers are notoriously inefficient). So you'll still need some other form of cooling, most likely ending up as dissipation to the air. Could make denser packing of processors in multiprocessor clusters possible, but I doubt if it would be worth it for a desktop PC, and probably completely impractical for a cell phone. But science journos need to fantasize sometimes.

[DetlefK]

3. nope, heat is dissipated as radiation

http://www.nature.com/nature/journal/v493/n7433/pdf/nature11721.pdf

Photon goes in, excites, photon+phonon go out.

This should only work for materials with a specific band-structure and for lasers with specific wavelengths.

And I guess, the outgoing radiation is spread out into all directions, that's why you can't see it. (Maybe, maybe... If the surface had a periodic nanostructure, we could force the outgoing infrared-radiation to be emitted in a specific direction/angle with respect to the surface... Are you pondering what I am pondering, Pinky?)