High Verdet constants and diamagnetic responses of GeS-InS-PbI chalcogenide glasses for integrated optics applications.

Chalcogenide glasses as kind of diamagnetic magneto-optical materials have promising applications in the field of integrated optics and optical communication systems due to their excellent properties, such as easy to be processed into waveguide and temperature independence of the Verdet constants. For clarifying the influence factors following the compositional variation on Faraday effect and finding a glass with a large Verdet constant, novel pseudo-ternary chalcogenide glass system, GeS - InS - PbI, was prepared and investigated. The composition, wavelength and temperature dependences on the Verdet constants were systematically investigated at the wavelengths of 635, 808, 980 and 1319 nm. PbI was confirmed to have positive contribution to the Verdet constant and the Becquerel rule was proved to be an effective guidance for predicting the Verdet constant in chalcogenide glasses. The 60GeS·15InS·25PbI glass was found to possess the largest Verdet constant (V = 0.215 min·G·cm, @808nm), which is great larger than that of commercial diamagnetic glasses. These glasses also possess good glass-forming ability and VIS-IR transmittance, therefore be a good candidate for next-generation integrated optical isolator and other magneto-optical devices.