A fresnel is a unit of frequency equal to 1012 s−1. It was occasionally used in the field of spectroscopy, but its use has been superseded by terahertz (with the identical value 1012 hertz).[1] It is named for Augustin-Jean Fresnel the physicist whose expertise in optics led to the creation of Fresnel lenses.[2]

References

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  1. ^ Bayliss, Noel S. "The permicron: a unit of wavenumber", Nature, vol. 167, p. 367, 3 March 1951.
  2. ^ Scientific Unit Conversion: A Practical Guide to Metrication Cardarelli, F. 1999. Springer Science & Business Media. ISBN 9781447108054