Evaluation of the systematic errors of polarimetric measurements: Application to measurements of the gyration tensors of a-Quartz by the HAUP

Ft was shown in the course of developing the high- Accuracy universal polarimctcr (HAUP) that any polarimetric optical analyses cannot be free from a systematic error y originating in the parasitic ellipti- cities of the constituent Nicol prisms. A method by which one can remove y in the HAUP method is presented. This has been successfully applied to measurements of the gyration tensors and birefringence of two enantiomorphic crystals of a-quartz. It was found that the order of magnitude of this error for a polarizer is about 10 4 and consequently y lies between 10^-4 and 10^-3 in typical optical systems. Our results, g, = 5-7±0-52 x 10^-5 and g₃₃ = - 13-6 ± 0-52 x 10^-5 with a wavelength of 6328 A for laevo- rotatory quartz at 300 K are in good agreement with some of the previous reports.