A new polarizing system for spectrophotometers

Abstract

The effect of scattered light in the nicol prism and an improved form of prism in which scattered light is much reduced is described. An improved polarizing system for spectrophotometers is described consisting of three nicols in tandem, the first and last being stationary and arranged to transmit light polarized in the same plane, the second prism being arranged to rotate. In such a system it is shown that the ratio of intensity follows the law I1/I2 = tan4 θ. The theoretical advantages of the system as compared with the usual system consisting of one fixed and one rotating nicol in which the ratio of intensity follows the tan2 θ law, are also discussed.