Florida Researchers Create Shortest Light Pulse Ever Recorded 76
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."
The width of a virus (Score:5, Informative)
To put that in perspective, light in a vacuum travels around 20 nm [google.com] in 67 attoseconds, so the width of the pulse is about the same as the width of the smallest virus [blogspot.com] or about 1/350th the 7um [wikipedia.org] diameter of a human blood cell.
Re:How do they measure this? (Score:5, Informative)
Short version: They use nonlinear optics and variable delay between two beam paths.
The technique is called Frequency-Resolved Optical Gating [wikipedia.org] (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.
Re:How do you even measure this? (Score:4, Informative)
Re:color (Score:2, Informative)
If you know at what energy levels the photons are released, you know the wavelength.