Effect of dysprosium active ions on spectral properties of KGW single crystals

Dysprosium (Dy) doped potassium gadolinium tungstate single crystals were grown by top seeded solution growth using K2WO4 as solvent. Two different concentrations of laser active ions were doped in the crystal. Crystals grown with lower growth rate using K2WO4 as solvent yielded better quality than that grown by K2W2O7 as solvent. Growth conditions, like cooling rate and the rotation rate were optimized. Absorption studies confirm dominant absorption peaks in the visible as well as in near infrared regions. Photoluminescence reveals a strong yellow emission for the doped samples and the emission intensity of 3% Dy doped sample is 1.4 times higher than that of 1% Dy concentration in KGW. Raman spectra indicate the characteristic vibrational modes corresponding to the tungstate anion. The intensity of peaks in Raman spectra are increased with increase in concentration of Dy, in addition to a slight shift in Raman frequency.

Research highlights▶ Dysprosium doped KGd (WO4) single crystals were successfully grown with TSSG method. ▶ There is strong yellow emission with narrow linewidth for doped crystals. ▶ Narrow and intense Raman lines observed for dysprosium doped KGW can be used for SRS applications.