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Florida Researchers Create Shortest Light Pulse Ever Recorded
SchrodingerZ writes "Researchers at the University of Central Florida have created the shortest laser pulse ever recorded, lasting only 67 attoseconds. An attosecond is a mere quintillionith of a single second (1/1,000,000,000,000,000,000). The record-breaking project was run by UCF Professor Zenghu Chang, using an extreme ultraviolet laser pulse. '"Dr. Chang's success in making ever-shorter light pulses helps open a new door to a previously hidden world, where we can watch electrons move in atoms and molecules, and follow chemical reactions as they take place," said Michael Johnson, the dean of the UCF College of Sciences and a physicist.' Its hoped that these short laser blasts will pave the way to better understand quantum mechanics in ways we have never before witnessed. In 2008 the previous record was set at 80 attoseconds, the pulse created at the Max Planck Institute in Garching, Germany."
To put that in perspective, light in a vacuum travels around 20 nm in 67 attoseconds, so the width of the pulse is about the same as the width of the smallest virus or about 1/350th the 7um diameter of a human blood cell.
Can't we get a video?
There was, but it was only 68 attoseconds long, so you must have missed it.
An enigma, wrapped in a riddle, shrouded in bacon and cheese
tl;dr
UNIX? They're not even circumcised! Savages!
A word to the wise when trying to get people excited about fundmental science: the number "1" followed by a lot of zeroes is meaningless to most people (even scientists). Please give us something to relate that number to and put it in scientific notation!
67 attoseconds = 6.7 x 10^–18 seconds
As a photochemist, I know that a femtosecond is (1 x 10^–15 seconds) is the on order of many "fast" chemical reactions, like visible light reacting with your eye, so attoseconds are faster than most chemical bonds breaking/forming.
Short version: They use nonlinear optics and variable delay between two beam paths.
The technique is called Frequency-Resolved Optical Gating (there are a bunch of derived techniques used in specific cases, like the one here), and is actually a brilliant idea when you think about it. You measure the spectrogram of a nonlinear function of the pulse and itself with variable delay.
A word to the wise when trying to get people excited about fundmental science: the number "1" followed by a lot of zeroes is meaningless to most people (even scientists). Please give us something to relate that number to and put it in scientific notation!
They did give a unit that scientists can relate to when they said "67 attoseconds". The 1/1,000,000,000,000,000,000 notation is just there for the layman for whom scientific notation means nothing, 1 x 10^-18 means little to most people, but lots of zeros make it clear that it's a very small number.
67 attoseconds = 6.7 x 10^–18 seconds
You're off by 10 -- 67 attoseconds = 67 x 10^-18, or 6.7 x 10^-17
A monochromatic wave, having zero extent in momentum space, has infinite extent in realspace.
A laser pulse whose duration is comparable to a single wave period as those in TFA are will in fact have a very broad energy spectrum, which can be understood both through time-energy uncertainty and by noting that a pulse waveform has a broad fourier spectrum, corresponding to broad energy distribution.
I end up saying or at least thinking this every time a science-breakthrough article comes by on Slashdot: If you think whatever someone did in cutting-edge experimental science is "easy," it's because you don't understand what they did and/or the theory behind it. Think before you speak: If it were actually easy, wouldn't they have already done it this way? Posting a "dumb scientists, that was easy" comment will bring only embarassment.
http://en.wikipedia.org/wiki/Frequency-resolved_optical_gating