Advances on the fabrication process of Er3+/Yb3+:GeO2–PbO pedestal waveguides for integrated photonics

• Advances on the fabrication of Er3+/Yb3+:GeO2–PbO pedestal waveguides are shown.
• Optimization was performed in lithography and plasma etching processes steps.
• 50% enhancement was obtained for the internal gain at 1550 nm under 980 nm pump.
• Decrease of about 50% was observed for the propagation losses at 632 and 1068 nm.

The present work reports the fabrication, passive and active characterization of Yb3+/Er3+ codoped GeO2–PbO pedestal waveguides. We show the advances obtained in pedestal fabrication by comparing waveguides obtained under different processes parameters. The thin films were deposited on previously oxidized silicon wafers in Ar plasma at 5 mTorr; pedestal waveguides, with 1–100 μm width range were defined by conventional lithography procedure, followed by reactive ion etching (RIE). A comparison between the results of propagation losses and internal gain is presented in order to show that the improvement of fabrication process contributed to enhance the performance of the pedestal waveguides. Reduction of about 50% was observed for the propagation losses at 632 and 1068 nm, whereas enhancement of approximately 50% was obtained for the internal gain at 1530 nm (4 and 6 dB/cm, for 70 μm waveguide width), under 980 nm excitation. The present results demonstrate the possibility of using Yb3+/Er3+ codoped GeO2–PbO as pedestal waveguide amplifiers.