Path-length difference between the arms of a two-beam interferometer.
Notes: - The term optical retardation is derived from 'phase retardation', which refers to the change in the phase of the electromagnetic radiation in the interferometer.
- SI unit: \(\pu{m}\). Common unit: \(\pu{cm}\).
Source:
PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 758 (https://doi.org/10.1515/pac-2019-0203)