angle of optical rotation, \(\alpha\)

https://doi.org/10.1351/goldbook.A00348
angle through which plane polarized light is rotated clockwise, as seen when facing the light source, in passing through an optically active medium.
Source:
Green Book,2nd ed., p. 33 (https://www.cintegrado.com.br/site/documentos/green_book_2ed.pdf)