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 prefixfemto and the SI unitsecond. 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.
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]
^Loh, Z.-H.; Doumy, G.; Arnold, C.; Kjellsson, L.; Southworth, S. H.; Al Haddad, A.; Kumagai, Y.; Tu, M.-F.; Ho, P. J.; March, A. M.; Schaller, R. D.; Bin Mohd Yusof, M. S.; Debnath, T.; Simon, M.; Welsch, R. (2020-01-10). "Observation of the fastest chemical processes in the radiolysis of water". Science. 367 (6474): 179–182. doi:10.1126/science.aaz4740. ISSN 0036-8075.
^Abbi, S. C. (2001). Nonlinear Optics and Laser Spectroscopy. United States of America: Alpha Science Int'l Ltd. p. 361. ISBN8173193541.
January 01, 1970
femtosecond, femtosecond, unit, time, international, system, units, equal, second, that, quadrillionth, millionth, billionth, second, context, femtosecond, second, second, about, million, years, light, travels, approximately, micrometers, femtosecond, distance. 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 mm 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 l c 600 10 9 m 3 10 8 m s 1 2 0 10 15 s displaystyle lambda over c 600 times 10 9 rm m over 3 times 10 8 rm m rm s 1 2 0 times 10 15 rm s 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 The colors of the visible light spectrum 6 Color Wavelengthinterval Cycle timeinterval Red 700 635 nm 2 3 2 1 fs Orange 635 590 nm 2 1 2 0 fs Yellow 590 560 nm 2 0 1 9 fs Green 560 520 nm 1 9 1 7 fs Cyan 520 490 nm 1 7 1 6 fs Blue 490 450 nm 1 6 1 5 fs Violet 450 400 nm 1 5 1 3 fsExamples edit46 fs the swiftest chemical reaction known radiolysis of water leads to the formation of a H2O ion which rapidly reacts to become hydronium H3O and a short lived hydroxyl radical OH 7 200 fs the average chemical reaction such as the reaction of pigments in an eye to light 5 300 fs the duration of a vibration of the atoms in an iodine molecule 8 See also editFemtochemistry Femtosecond pulse shaping Ultrafast laser spectroscopy Mode locking Microsecond Millisecond Nanosecond Orders of magnitude time Ahmed ZewailReferences edit Femtosecond Merriam Webster definition Merriam Webster Online Dictionary 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 amp 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 a b 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 Loh Z H Doumy G Arnold C Kjellsson L Southworth S H Al Haddad A Kumagai Y Tu M F Ho P J March A M Schaller R D Bin Mohd Yusof M S Debnath T Simon M Welsch R 2020 01 10 Observation of the fastest chemical processes in the radiolysis of water Science 367 6474 179 182 doi 10 1126 science aaz4740 ISSN 0036 8075 Abbi S C 2001 Nonlinear Optics and Laser Spectroscopy United States of America Alpha Science Int l Ltd p 361 ISBN 8173193541 Retrieved from https en wikipedia org w index php title Femtosecond amp oldid 1217427944, wikipedia, wiki, book, books, library,
