The effect of excited-state absorption on up-conversion photoluminescence behavior in erbium-ion doped gallium lanthanum sulphide-oxide glasses

Photoluminescence (PL) of Er3+ ions embedded in GaLaS(O) glass at excitation wavelengths of 488, 532, 660, 808, and 980 nm has been studied. Typical cases at which the ratios of the optical transition intensities have no dependence on the pumping intensity have been considered. For the case of pumping at the 488 nm wavelength the method of extrapolation coefficients, which reveals the up-conversion nature of PL “mimicking” a “normal” PL, has been demonstrated. The thermal coupling of S3/24 and H11/22 manifolds, which are responsible for the intense PL in the green region of the visible spectral range, is discussed.