Optical absorption and magnetic circular dichroism of ER(3+)-doped aluminosilicate glasses

The magnetic circular dichroism (MCD) and optical absorption spectra are reported for varying erbium(3+) concentrations in aluminosilicate glasses. Visible MCD data are obtained at a field strength of 1.8 Tesla and at a base temperature of 1.7 K. The temperature dependence in the range up to 300 K is also studied. A striking result of this work is the drastic change in both shape and position of many of the MCD absorption bands with erbium(3+) concentration. These changes give insight into the nature of the erbium ion’s crystal field and thus its local environment. The MCD (or Faraday) parameters are determined via the method of moments.