Peculiarities of Er3+ photoluminescence in halogen-doped amorphous silica

The spectra and photoluminescence kinetics of Er³⁺ ions embedded in amorphous fluorine- and chlorine-doped silica matrices synthesized by surface-plasma chemical vapor deposition were investigated at 27–300 K. Luminescence was excited with an Ar⁺ laser at a wavelength of 514.5 nm and with a diode laser at a wavelength of 975 nm. Narrow and well-expressed components of Stark sublevels with a small contribution of inhomogeneous broadening intrinsic to Er³⁺ ions in crystalline rather than amorphous matrices were revealed and identified in photoluminescence spectra. The structure of Stark sublevels was well-resolved at low temperatures. The presence of the well-resolved Stark structure in spectra was indicative of stable anion complex formation in Er³⁺ environment presumably associated with halogen incorporation. This environment was formed at a stage of the low-temperature plasma-chemical synthesis and was destroyed at glass fusion.