Optical Gain in Eu-Doped Hybrid Nanocrystals Embedded SiO2-HfO2-ZnO Ternary Glass-CeramicWaveguides

Rare-earth doped transparent glass-ceramic waveguides are playing a very crucial role in integrated optics. We fabricated ZnO-HfO2 hybrid nanocrystals embedded with 70 SiO2–(30-x) HfO2–x ZnO (x = 0, 2, 5 and 7 mol %) ternary transparent glass-ceramic waveguides doped with 1 mol % Eu-ions. The formation and size of the nanocrystals evolved with an increase in ZnO concentration in the glass-ceramic waveguides. In this context, key factors of such nanocrystals embedded active glass-ceramic waveguides were optical losses and transparency. A lab-built m-line experimental set-up was used for the characterization of the waveguides. On the other hand, optical gain measurements of the Eu-doped hybrid nanocrystals embedded glass-ceramic waveguides were performed using the variable stripe length method. The optical amplification of the waveguides was investigated on the red emission line (5D0 → 7F2) of Eu-ions pumped by a 532 nm laser in a stripe-like geometry generated by a cylindrical lens. Here, we report, the optical gain in rare-earth activated glass-ceramic waveguides with nanocrystals of varying sizes formed in the waveguides with increasing ZnO concentration.