Faraday Rotation measurement of the Verdet Constant of SF-57 glass at 650 nm

Abstract

Light emitted from a laser was directed into a solenoid, with a glass rod inside, and then into a polarizer to measure the angle of rotation. As we changed the polarizer angle, the intensity of the light followed a cosine squared function. A Verdet constant is specific to each medium which describes the wavelength dependent optical strength. Three different methods were used to determine the Verdet constant of the glass rod (SF-57): 1) directly measuring the shift angle with and without an applied magnetic field, 2) measuring the voltage proportional to light intensity at a particular angle while changing the field, 3) using an alternating current to generate an alternating field to measure the corresponding alternating voltage. We measured a Verdet constant of 0.0189 \(\pm\) 0.00172 \(\frac{radians}{mT\cdot m}\), 0.01856 \(\pm\) 0.000156 \(\frac{radians}{mT\cdot m}\), and 0.017665 \(\pm\) 0.000609 \(\frac{radians}{mT\cdot m}\) for methods one, two and three respectively. These values of Verdet constants agree with the literature.