The optical rotation (α) can be measured with the product range of Schmidt + Haensch’s Polarimeters and is expressed in angular degrees. There is a great number of organic and inorganic substances being optically active in their crystalline, liquid or dissolved state. That means, these substances are able to rotate the direction of oscillation of polarized light around a determined angle. This is called optical rotation. The optical rotation can be measured very precisely with Schmidt + Haensch’s Polarimeters. Polarized light is light, which’s vibration pattern exhibits preference. If natural light passes through a so called polarizing filter, most of its other vibrating directions will be filtered out, leaving only one specific direction. If this light is oscillating in only one plane, it is called linearly polarized. Optical rotation is the rotation of the plane of polarization around the optical axis of linearly polarized light as it travels through optically active materials.