The reciprocal of the
wavelength,
,
or the number of waves per unit length along the direction of
propagation.
The SI unit is
, but a commonly used unit is
.
Symbols
in a vacuum,
in a medium.
Source:
PAC, 1996, 68, 2223
(Glossary of terms used in photochemistry (IUPAC Recommendations 1996))
on page 2283
PAC, 1985, 57, 105
(Names, symbols, definitions and units of quantities in optical spectroscopy (Recommendations 1984))
on page 109
,
