Improvement of the Faraday effect in Ge-S based chalcogenide glasses via gallium and lead compositional modifications

The diamagnetic performance of GeS2-Ga2S3 and GeS2-Ga2S3-PbI2 chalcogenide glasses were investigated, and the composition, wavelength and temperature dependences of the Verdet constant were discussed in detail. It indicates that the contributions to the Verdet constant for each kind of ion are in the order of VPb>VGa>VGe in these chalcogenide glasses, and the Becquerel rule is proved to be an effective guidance for predicting the Verdet constant value. A large Verdet constant is obtained in 68GeS2·17Ga2S3·15PbI2 composition glass and the value is 0.230 min·G−1·cm−1 at 635nm, which is greatly larger than those of commercial diamagnetic glasses. Besides, the temperature coefficient of Verdet constant can be regarded as a constant between 278 and 368 K, indicating these chalcogenide glasses are good candidates for magneto-optical devices in temperature instability conditions.