Investigation of the Faraday effect in tellurite glass optical fibre

The Faraday effect of a tellurite glass in the bulk and fibre form was investigated for magneto-optic applications. Polarization analysis showed that an optical beam linearly polarized at the multimode fibre input changed to elliptically polarized after propagating down the fibre and the result was compared with a standard silica optical fibre. However, the elliptical distribution remained unchanged with or without applied magnetic field, demonstrating that no circular dichroism occurs within the fibre. The Verdet constant values of the tellurite bulk glass diverged by less than 3% from the values measured on the fibre whose core had the same composition of the bulk glass. The results of the investigation demonstrate that tellurite glass fibres obtained by preform drawing are suitable for developing devices for magneto-optic applications.