Near-IR emission of Er3+ ions in CsCl-Ga-Ge-S glasses excited by visible light

Fluorescence of 65GeS2-25Ga2S3-10CsCl glasses doped with Er has been investigated at room and liquid nitrogen temperatures. Strong emission lines at ∼1 and ∼1.5 μm are observed at room temperature in Er-doped samples when excited with ∼530 nm wavelength. At cryogenic temperature, this fluorescence is observed even at lower excitation wavelengths (∼400-450 nm). The other observed emission and absorption lines agree well with known energy level transitions of Er3+ ions incorporated in the glass matrix and temperature behavior of absorption spectra. The difference between room and liquid nitrogen temperature up-conversion emission is observed under femtosecond pulsed 800 nm laser excitation.