A Measurement Technique of the Tiny Rotatory Angle of Polarization
Chang Yue;Qian Xiaoling (Physics Department, the Capital Normal University Beijing 100037)
This experiment demonstrates a measurement technique of very small rotatory angle of polarization. Faraday rotatory angle is measured in ethanol solution of concentration 50% usiflg 632.8 nm He-Ne laser and 532 nm LD pump solid laser as measuring sourcest respectively. The rotatory ang1e can take values in the mag-nitude of sub-millidegree (10-4degrees ) as the intensity of induction field changes.Applying this polarimetric technique, the rotatory angle can be measured in the cane sugar solution of concentration of 10-4g/ml. Therefore it provides a good polarimetric method for chemical and life substances with small Verdet constants.