Editing Ultrashort pulse (section)

{{Short description|Laser pulse with duration a picosecond (10^-12 s) or less}}

In [[optics]], an '''ultrashort pulse''', also known as an '''ultrafast event''', is an [[electromagnetic pulse]] whose time duration is of the order of a [[picosecond]] (10<sup>&minus;12</sup> second) or less. Such pulses have a broadband [[optical spectrum]], and can be created by [[mode-locking|mode-locked]] oscillators. Amplification of ultrashort pulses almost always requires the technique of [[chirped pulse amplification]], in order to avoid damage to the gain medium of the amplifier.

They are characterized by a high peak [[intensity (physics)#Alternative definitions of "intensity"|intensity]] (or more correctly, [[irradiance]]) that usually leads to nonlinear interactions in various materials, including air. These processes are studied in the field of [[nonlinear optics]].

In the specialized literature, "ultrashort" refers to the [[femtosecond]] (fs) and [[picosecond]] (ps) range, although such pulses no longer hold the record for the shortest pulses artificially generated. Indeed, x-ray pulses with durations on the [[attosecond]] time scale have been reported.

The 1999 [[Nobel Prize in Chemistry]] was awarded to [[Ahmed H. Zewail]], for the use of ultrashort pulses to observe [[chemical reaction]]s at the timescales on which they occur,<ref>{{cite web |title=The Nobel Prize in Chemistry 1999 |url=https://www.nobelprize.org/prizes/chemistry/1999/ |website=NobelPrize.org |access-date=18 October 2023}}</ref> opening up the field of [[femtochemistry]].
A further Nobel prize, the 2023 [[Nobel Prize in Physics]], was also awarded for ultrashort pulses. This prize was awarded to [[Pierre Agostini]], [[Ferenc Krausz]], and [[Anne L'Huillier]] for the development of attosecond pulses and their ability to probe electron dynamics.<ref>{{cite web |title=The Nobel Prize in Physics 2023 |url=https://www.nobelprize.org/prizes/physics/2023 |website=NobelPrize.org |access-date=18 October 2023}}</ref>