Reflection-absorption with very thin layers of an absorbing material on a metallic substrate and the
angle of incidence between
\(\pu{70\!^{\circ}}\) and
\(\pu{90\!^{\circ}}\).
Note:
As the incident radiation beam travels nearly parallel to the sample surface, the electric vector of the radiation is then either parallel or nearly perpendicular to the surface.
Source:
PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 762 (https://doi.org/10.1515/pac-2019-0203)