optical rotation angle
Technical term in chemistry; the angle by which plane-polarized light is rotated when passing through an optically active substance. Often used in the context of polarimetry.
See also: 旋光度
By measuring the optical rotation angle, the optical purity of the sample can be determined.
Compound of 旋光 (optical rotation) + 角 (angle). The term is a direct technical coinage in chemistry.