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Name: Stanley
Status: student
Age: 20s
Location: N/A
Country: N/A
Date: 1999 

What is a femtosecond laser? How does it work?

Hi Stanley!

Nice asking that... Femtosecond laser is an ultra-fast radiation that has a temporal resolution correspondent to the speed, or rate of some chemical reactions. With experiments utilizing that tecnique it is possible to observe atoms in molecules in the course of some chemical reactions in gases, liquids and solids, and also in catalytic processes and biological ones.

Femtochemistry, as are called these studies, is the research field of Professor Ahmed H. Zewaill (CalTech) and gave him the 1999 Chemistry Nobel Prize. The name Femto came from a danish word for the number 15. One femtosecond, the unit used to measure the speed of some chemistry reactions (or transient stages) is equal to 10 to minus 15.

Thanks for asking NEWTON!

(Dr. Mabel Rodrigues)

I'm not a physicist; I can only answer half of your question. A "femtosecond laser" is a laser that can produce a pulse of photons that is shorter than a nanosecond. (A nanosecond is 1000 femtoseconds.) How such lasers are constructed and how they work I don't know. They are used to probe very fast chemical reactions, such as the breaking of bonds between atoms.

Richard E. Barrans Jr., Ph.D.
Assistant Director, PG Research Foundation
Darien, IL USA

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