Study of the influence of Tb-Sc-Al garnet crystal composition on Verdet constant

The influence of the composition of Tb-Sc-Al garnet crystals (TSAG) on the value of Verdet constant was investigated at the wavelengths of 400-1060 nm. It was found that this value increased both, with the decrease of Sc3+ ions content and with the decrease of lattice parameter. The value of Verdet constant of TSAG crystals depend on lattice parameter value and increased from 0.168 to 0.198 min/(Oe cm) (at λ = 1064 nm) with the decrease of Sc3+ ions content from 1.76 to 1.3 f.u. The value of Verdet constant for TSAG crystals with Sc3+ ions content of 1.3 f.u. can be described using one- and two-oscillator models with the same accuracy. The absorption at the wavelengths of 226 and 272 nm for the sample with a thickness of 13 μm was observed and wavelengths were used for calculations of Verdet constant in accordance with the two-oscillator model.