IR transmission and emission spectra of erbium ions in fluoroindate glass

Multicomponent fluoride glasses with relatively high IR transparency have been prepared. These glasses have IR cut-off (above 20 μm) at longer wavelength than other fluoride type-glassy systems. The light transmission is about 80% at wavelengths up to 15 μm in the InF3-based system doped with Er3+ ions. This suggests the possibility to obtain optical fiber for coupling to infrared emitting sources such as the CO2 laser, for optical applications. The emission spectra have been recorded at room temperature. Four emission bands centered at 976, 847, 668 and 550 nm correspond to the 4I11/2–4I15/2, 4S3/2–4I13/2, 4F9/2–4I15/2 and 4S3/2–4I15/2 transitions of erbium ions, respectively. The inhomogeneous transition linewidths of Er3+ ions in fluoroindate glass have been investigated after heat treatment. Increased heating time increases the observed linewidth. This effect is related to the formation of several crystalline phases in this multicomponent system during heat treatment. However, spectral line narrowing has been detected under conditions of short time heating in comparison to an unheated sample.