New design of spectropolarimeter

Abstract

A new design of spectropolarimeter is described, in which the functions of monochromator and polarimeter are combined by using two crystalline quartz prisms both to disperse the radiation and to polarize it. The two prisms are fixed in position, wavelength scanning being achieved by the rotation of two plane mirrors in unison about a common axis. The optical rotation of the specimen is compensated by means of a Faraday cell and is thus measured in terms of current. The present experimental system can be used over a wavelength range from 600 to 220 mμ, the full-scale reading varying with wavelength, being equivalent to about 0.1° at 600 mμ and rising to about 1.1° at 220 mμ. The output noise level is between about 0.1 and 0.5% of the full-scale rotation over this spectral range.