SiO2-SnO2 glass-ceramic planar waveguides activated by rare earth ions

Eu3+ doped (100-x) SiO2 - x SnO2 (x = 8, 16 and 25 mol %) glass-ceramic waveguides were fabricated by sol-gel technique with dip-coating processing at 800 °C. Higher thermal treatments led to the formation and growth of SnO2 nanocrystals in the matrix, enhancing the 5D0 -> 7F2 emission of Eu3+. Spectroscopic investigations reveal the evolution of a centro-symmetric local environment around the Eu3+ ion. This property of glass-ceramic waveguides can be exploited for obtaining a higher rare-earth concentration in a smaller volume. The glass-ceramic waveguides exhibited low-losses (0.8 ± 0.2 dB/cm at 632.8 nm) and thus are promising for the development of high-gain integrated optical amplifiers.