High-speed photography using lasers

Wired had an article titled “Laser-Firing Physicists Take High-Speed Photography to the Attosecond Range“.

Capturing images of fleeting events — a horse’s gallop, a bullet’s impact, an electron’s escape — is easy if you have the right equipment. Faster camera shutters used to be enough, but recently lasers have let physicists break the femto- and attosecond barriers, compressing the temporal resolution of images down to the time it takes light to cross a hydrogen atom.

They mentioned two examples of high speed photography utilizing ultrafast lasers.

4) Element Melting
Shooter R. J. Dwayne Miller, 2007
Shutter speed 300 femtoseconds (300 x 10-15)
By the 1980s, lasers could deliver bursts of light faster than a single molecular vibration. A “pump” pulse triggers a reaction, and a “probe” pulse follows, acting like a strobe. Miller, a University of Toronto chemist, melted aluminum with a laser and used an electron pulse to catch the action at a molecular level. Now he’s working on silicon.

Photo: Christoph T. Hebeisen

5) Electron drift
Shooter
Ferenc Krausz, 2007
Shutter speed 110
attoseconds (110 x 10-18)
The pump-probe technique has been modified to pare pulse times to attoseconds by using photons emitted when electrons get excited out of their orbit and crash back in. That’s short enough to measure the movement of other electrons as they enter an extreme UV wave. The pairs of dotted lines span the time between two electron crossings.

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