A femtosecond is a unit of time in the International System of Units (SI) equal to 10−15 or 1⁄1 000 000 000 000 000 of a second; that is, one quadrillionth, or one millionth of one billionth, of a second.[1] For context, a femtosecond is to a second as a second is to about 31.71 million years; a ray of light travels approximately 0.3 μm (micrometers) in 1 femtosecond, a distance comparable to the diameter of a virus.[2] The first to make femtosecond measurements was the Egyptian Nobel Laureate Ahmed Zewail, for which he was awarded the Nobel Prize in Chemistry in 1999. Professor Zewail used lasers to measure the movement of particles at the femtosecond scale, thereby allowing chemical reactions to be observed for the first time.
The word femtosecond is formed by the SI prefix femto and the SI unit second. Its symbol is fs.[3]
A femtosecond is equal to 1000 attoseconds, or 1/1000 picosecond. Because the next higher SI unit is 1000 times larger, times of 10−14 and 10−13 seconds are typically expressed as tens or hundreds of femtoseconds.
Typical time steps for molecular dynamics simulations are on the order of 1 fs.[4]
The periods of the waves of visible light have a duration of about 2 femtoseconds. The precise duration depends on the energy of the photons, which determines their color. (See wave–particle duality.) This time can be calculated by dividing the wavelength of the light by the speed of light (approximately 3×108 m/s) to determine the time required for light to travel that distance.[5]
^Compared with overview in: Fisher, Bruce; Harvey, Richard P.; Champe, Pamela C. (2007). Lippincott's Illustrated Reviews: Microbiology (Lippincott's Illustrated Reviews Series). Hagerstown, MD: Lippincott Williams & Wilkins. p. 3. ISBN 978-0-7817-8215-9.
^NIST. "NIST Definitions of the SI units".
^"Femtosecond: use in molecular dynamics simulation". LAMMPS Molecular Simulator.
^Andrew M. Weiner (2009). Ultrafast Optics. Wiley. ISBN 978-0-471-41539-8.
^Craig F. Bohren (2006). Fundamentals of Atmospheric Radiation: An Introduction with 400 Problems. Wiley-VCH. p. 214. Bibcode:2006fari.book.....B. ISBN 978-3-527-40503-9.[permanent dead link]
A femtosecond is a unit of time in the International System of Units (SI) equal to 10−15 or 1⁄1 000 000 000 000 000 of a second; that is, one quadrillionth...
reactions on extremely short timescales (approximately 10−15 seconds or one femtosecond, hence the name) in order to study the very act of atoms within molecules...
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are used to disclose the physics of ultra-fast phenomena in the few-femtosecond and attosecond time-domain. To generate a traveling pulse with an ultrashort...
energy ranges; some common methods are listed below. Dynamics on the femtosecond time scale are in general too fast to be measured electronically. Most...
years 10−12 s ps picosecond 1012 s Ts terasecond 31,700 years 10−15 s fs femtosecond 1015 s Ps petasecond 31.7 million years 10−18 s as attosecond 1018 s...
and multiphoton processes in the ionization of Ar and Xe using intense femtosecond laser pulses". Journal of Physics B: Atomic, Molecular and Optical Physics...
transfer in antenna chlorophyll Thylakoid membranes in the chloroplasts Femtosecond to picosecond 2 Transfer of electrons in photochemical reactions Picosecond...
are acting like a glue sticking atoms together, heating electrons by a femtosecond laser alters the properties of this "glue", which may break the bonds...
and Baikuff suggested this technique in 1979. This technique uses a femtosecond laser to do capsulotomy. The laser produces a precisely spaced row of...