Influence of gold nanoparticles on the 153 µm optical gain in Er^3+/Yb^3+: PbO-GeO_2 RIB waveguides

We report the fabrication of waveguide amplifiers produced by RF-sputtering, using a PbO-GeO(2) glass (PGO glass) film codoped with Er(3+)/Yb(3+). RIB waveguides were obtained from PGO thin films using optical lithography followed by reactive ion etching process. The optical losses in the waveguide were ≈1.0 dB/cm and the maximum internal gain at 1.53 µm, with excitation at 980 nm, was 3 dB/cm. Nanostructured gold films deposited on the waveguides enhanced the Er(3+) ions photoluminescence (PL) by ≈400% in the red region and ≈30% in the infrared, under 980 nm pumping. The optical gain was enhanced and reached 6.5 dB/cm. The results demonstrate that the PGO waveguides, with or without gold nanoparticles, are promising for integrated photonics.