The Power of Light: Moving Macroscopic Amounts of Matter

physorg.com ^ | January 29th, 2009 | Lisa Zyga

[Ernest_at_the_Beach]

A quartz glass structure that formed after (a) 95 seconds and (b) 300 seconds of laser annealing, where the sample in (b) is a cross-section. Scientists discovered that, under intense light irradiation, molten silicon powder particles can form macroscopic structures up to 7 mm high. Image credit: J. Günster, et al. (c)2009 AIP.

(PhysOrg.com) -- Since 1970, scientists have been working with “optical tweezers” - lasers that move microscopic amounts of matter using forces originating from the light matter interaction. Now, for the first time, researchers have demonstrated that light-induced forces can move macroscopic amounts of matter, as well.

The German team, led by Jens Günster of the CiC Ceramic Institute Clausthal GmbH in Clausthal-Zellerfeld, Germany, in collaboration with researchers from the Deutsches Zentrum für Luft und Raumfahrt, Institute of Composite Structures and Adaptive Systems in Braunschweig, Germany, has recently published the achievement in a recent issue of Applied Physics Letters. The scientists described a phenomenon not yet observed: Under intense light irradiation, molten silicon powder particles (about 40 micrometers in diameter) can form macroscopic structures up to 7 mm high.

“We regard the fact that laser light can directly apply forces to a dielectric liquid on a macroscopic level as a finding of great significance,” Günster told PhysOrg.com. Those applied forces are direct, yet don’t require any physical contact with the liquid.

In experiments, the researchers used a CO2 laser to melt a pile of pure silicon powder, which has a melting temperature of 1713°C (3115°F). At its highest power output of 12 kW, the laser could melt the silicon powder almost instantaneously. However, the researchers lowered the power output to 9.6 kW to avoid excessive evaporation of the silicon.

[martin_fierro]

The German team, led by Jens Günster of the CiC Ceramic Institute Clausthal GmbH in Clausthal-Zellerfeld, Germany, in collaboration with researchers from the Deutsches Zentrum für Luft und Raumfahr

Ich bin ein Raumfahrter.

[Buck W.]

“Ich bin ein Raumfahrter.”

Best, then, to clear the Raum (apologies for the gratuitous joke at the expense of the German language.).

[the long march]

Not all that new or interesting to those of us in laserdom

[Ernest_at_the_Beach]

laserdom

It's a mysterious world not known by many of us....but good tutorials would be interesting.

[Ernest_at_the_Beach]

All I know is Heat causes stuff to splatter.

[mamelukesabre]

What good is it? are they going to start building IC chips with lasers instead of acid etching?

[Ernest_at_the_Beach]

These guys just do “Findings”....another team decides what to do with it....if anything....LOL!

[6SJ7]

Next step. Attaching the frikin’ lasers to sharks.

[Ernest_at_the_Beach]

LOL!