DISPERSION OF FARADAY ROTATION IN SOME OPTICAL GLASSES

Abstract

The dispersion of magneto-optic rotation has been studied in a set of eight optical glasses of known composition from y 5780 to y 3650 A. Dispersion formulx for optical refraction have been proposed for these glasses using two mean absorption wavelengths. In all the glasses A 600 A is assumed to be one absorption wavelength and the other varied with the composition of the glass. But the experimental data on magnetic gyration in each glass has been fitted up into a dispersion formula by using only the near ultraviolet absorption wavelength that is responsible for refractive dispersion and it is found that the absorption wavelength in the far ultraviolet, i.e., y 600A is practically ineffective towards magnetic gyration. The value of the anomaly factor in the glasses containing Al 203,B203 , BaO is noticed to be low compared to the glasses containing the oxides of lead and zinc. It has been possible to establish that the network forming ions like boron, aluminium, barium, etc., diminish the value of y thereby indicating the presence of covalent binding between the ions in them.