Light Slowed Down To 127 mph

Makarand writes "Although slowing down a light beam is as simple as passing it through a window pane, slowing down light dramatically has always involved extremely low temperatures and rooms full of complex equipment. A new small device developed at the University of Rochester can now slow light down to 127 mph without using the room-filling mechanisms previously required. The new technique uses a laser beam to create a hole in the absorption spectrum of a common ruby at room temperatures that can allow a second laser beam, with a frequency slightly different than the first laser, to shine through that hole at a greatly reduced speed. This light slowing device might find applications in the telecommunications industry."

Comments

Moo

[Chacham]

The best part is, that we all know that when traveling faster than the speed of light in a vacuum, you can go backwards in time. So, by traveling slower than light in a vacuum, you move *forward* in time. As if this very moment I am traveling forward!

If you'd like to try this, get an airtight container and step inside. Remove all the air (such as with a match). Then start moving slowly. When you get out of the jar you sill notice that it is *later* then when you got in!

Non-believers

[Sprunkys]

Not many people seem to believe this. I don't really see why not as this has already been done long ago by Ad Lagendijk and others (please note, the original research was done at Amsterdam, not the University of Twente).

Furtermore, Bigelow e.a published their paper in the Physical Review Letters on March the 21st, not on the first of April. They submitted their paper on 31 October 2002.

From what I could make up of it, Ad Lagendijk did this in the early nineties by having the light reflect off of particles and thus slowing it down effectively (it doesn't emerge on the other side of the container at t=x/c where t is the time, x is the width of the container and c is the speed of light).
Bigelow, Lepeshkin and Boyd really just created a ruby crystal with an enormously high refractive index, effectively slowing down the light. Nothing really odd.

Concerning the application of this research in telecommunications the article mentions the following:

Boyd anticipates that the slow light device will find a role in the telecommunications industry. When two signals from fiber optic lines merge, the two signals may reach the merging router at the exact same moment and need to be separated slightly in time so they can be laid down one after another. Like two cars merging on a highway where one may need to slow down to let another car into the lane, a light-slowing device could help ease congestion on fiber optic lines and simplify the process of merging signals on busy networks.

This I know nothing about, however, this does seem a bit odd to me as I don't know how they intend to figure out where the light is in order to know how much to slow it down.

Primary use of this technology

[Tikiman]

This technology will finally enable us to create "gun-style" laser weapons that can be ducked, dodged, and deflected with light sabres.