fem·​to·​sec·​ond ˈfem(p)-tə-ˌse-kənd How to pronounce femtosecond (audio)
: one quadrillionth of a second

Examples of femtosecond in a Sentence

Recent Examples on the Web Zewail, who would go on to win a Nobel Prize for his research, measured these miniscule changes in femtoseconds; a femtosecond is one millionth of a billionth of a second. NBC News, 19 Oct. 2020 During the late 1980s and early 1990s, however, the pulse durations were brought down to as little as a few femtoseconds (a femtosecond is equal to 10–15 second), approaching the time frame of atomic motions. Quanta Magazine, 30 Sep. 2020 One femtosecond is one-quadrillionth of a second—that’s one millionth of one billionth of a second! Kat Friedrich, Popular Mechanics, 14 June 2023 Ochiai’s setup, nicknamed Fairy Lights, employs much shorter femtosecond laser pulses that are much less dangerous despite having a high peak intensity, Ochiai says. Mark Aramo, Discover Magazine, 11 Apr. 2022 One evening while working in the lab, Du accidentally lifted his goggles while aligning the mirrors of a femtosecond laser, then a very new type of laser that emitted an extremely short pulse of light. Katie Hunt, CNN, 14 Sep. 2022 Developed during the 1990s, the technique uses ultra-short laser pulses—a femtosecond is one-millionth of a billionth of a second—which produces no heat to cut into a surface of an object. Bryan Hood, Robb Report, 23 Nov. 2021 An encounter of a PBH with a human body would represent a collision of an invisible relic from the first femtosecond after the big bang with an intelligent body—a pinnacle of complex chemistry made 13.8 billion years later. Avi Loeb, Scientific American, 6 June 2021 Ultrashort lasers produce pulses with a duration measured in femtoseconds (a femtosecond is 10-15 or a million-billionth of a second), and while their overall energy may be small, the power level for that brief duration is extremely high. David Hambling, Forbes, 11 Mar. 2021 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'femtosecond.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1976, in the meaning defined above

Time Traveler
The first known use of femtosecond was in 1976

Dictionary Entries Near femtosecond

Cite this Entry

“Femtosecond.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/femtosecond. Accessed 1 Oct. 2023.

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