EPR and optical spectroscopy of Cr3+ ions in barium gallo-germanate glasses containing B2O3/TiO2

Abstract

The remarkable variety of glasses doped with transition metal ions is a major reason for the growing popularity of spectroscopic studies to identify their optical properties. This study presents interesting results of analyzing the relationship between structural and optical properties of multicomponent germanate glass systems doped with Cr3+ ions. The chemical composition of the developed glasses was changed as a function of boron oxide and titanium oxide. EPR studies showed that each glass system exhibits two resonance signals in the low and high magnetic fields, respectively. The optical properties of the fabricated glasses were analyzed by recording optical absorption, excitation, and emission spectra. The calculated spectroscopic parameters showed very well the changes of the crystal field strength around Cr3+ ions. The used approach perfectly demonstrates the changes in the profile of the recorded luminescence bands related to the 4T2 → 4A2 and 2E → 4A2 transitions of trivalent chromium ions. These findings set a new direction in infrared photonics because show a way to effectively tune the unique optical properties of Cr3+ ions from the change of the chemical composition of the germanate glassy matrix.