COMPUTER MAGNETO-OPTICAL EXPERIMENT

A computer model of a dichrograph is developed which presents the diagram of a real apparatus detecting the light intensity difference for two orthogonal polarizations. The device is operated in the polarization modulation and lock-in detection mode and provides the exact calculation of output signal shape and spectrum at any set of optical elements with any combination of linear and circular birefringence and dichroism. Variable parameters are not only polarization characteristics of a sample, but also those of optical elements set by an operator, as well as so important for precision measurements values as polarization modulation amplitude, static spurious birefringence in a piezooptical modulator, etc. Given the assumed response of different sample parameters to external effects, e.g. a magnetic field, one can predict the measurement results. On the other hand, while operating together with a real set-up, the model makes it possible to timely analyze the result obtained and possible artifacts. As a result, the computer experiment accounts for an extraordinary shape of the MCD contour of one of the exciton-magnon absorption bands in antiferromagnetic cobalt fluoride. Besides, the question is studied whether rotation of a linear anisotropic sample about the set-up optical axis is expedient to eliminate the spurious contribution to circular dichroism considered from linear effects. 1