Optical absorption and photoluminescence properties of chromium in different host glasses

The optical absorption, excitation and fluorescence spectra, and emission lifetimes of chromium (III) were investigated in a wide variety of oxide glasses (aluminosilicate, aluminate and phosphate). For all glasses, weak crystal field strengths were deduced from the absorption spectra. The effect of the glass matrix and the Cr3+ concentration on the fluorescence properties of Cr3+ ions were investigated. An increased fluorescence intensity of Cr3+was found for glasses of low optical basicity, the spectral position of the Cr3+ absorption and emission, however, was hardly influenced by the glass composition. The optical absorption spectra of the chromium doped aluminosilicate and aluminate glasses showed the presence of CrVI, while in phosphate glasses most chromium occurred as Cr3+ ions. Furthermore, for the glass with the lowest basicity, the Cr3+concentration was optimized in order to achieve maximum fluorescence emission intensity.