Research on the magneto-optical properties of Tb3+-Ho3+ co-doped GeO2-B2O3-P2O5-ZnO (GBPZ) Faraday glass

In this paper, 32GeO ₂–20B ₂O ₃–5P ₂O ₅–3ZnO-40Tb ₂O ₃-xHo ₂O ₃ ( x = 0, 2, 4, 6, 8 and 10 mol%) Faraday glasses doped with different concentrations of Ho ³⁺ ions are prepared. The structure and physical properties of the 32GeO ₂–20B ₂O ₃–5P ₂O ₅–3ZnO-40Tb ₂O ₃-xHo ₂O ₃ ( x = 0, 2, 4, 6, 8 and 10 mol%) Faraday glass system are investigated by XRD, FT-IR and theoretical calculations. The effect of the different concentrations of Ho ³⁺ ions, incident wavelengths and test temperatures on the Verdet constants are studied. It was found that the magneto-optical properties of 32GeO ₂–20B ₂O ₃–5P ₂O ₅–3ZnO-40Tb ₂O ₃-xHo ₂O ₃ ( x = 0, 2, 4, 6, 8 and 10 mol%) Faraday glass has a certain dependence on the changes of incident wavelength and the test temperature. At room temperature, with the increase of Ho ³⁺ ion doping concentrations, the values of Verdet constants increase continuously at 633 nm. 32GeO ₂–20B ₂O ₃–5P ₂O ₅–3ZnO-40Tb ₂O ₃–10Ho ₂O ₃ Faraday glass has the highest Verdet constant value (-172.65 rad/(T·m)), which is increased by -42.35 rad/(T·m) compared with 32GeO ₂–20B ₂O ₃–5P ₂O ₅–3ZnO-40Tb ₂O ₃–10Ho ₂O ₃ Faraday glass without Ho ³⁺ ions (-130.30 rad/(T·m)). And it is much higher than that of the commercialized terbium gallium garnet crystal (-134 rad/(T·m)), indicating that the incorporation of Ho ³⁺ ions with a large magnetic moment can significantly improve the properties of the magneto-optical glass, which has not been reported in other literatures. At the same time, it is found that the Verdet constant of 32GeO ₂–20B ₂O ₃–5P ₂O ₅–3ZnO-40Tb ₂O ₃–10Ho ₂O ₃ Faraday glass decreased with the increase of test temperature. These findings have important implications for the application of magneto-optical glass in the fields of optical fiber, laser, information, and magneto-optical devices.