Optical gain at 1.53 μm in Er3+-Yb3+ co-doped porous silicon waveguides

Erbium-ytterbium (Er-Yb)-co-doped porous silicon planar waveguides were prepared from P+-type (100) oriented silicon wafer. Erbium and ytterbium ions were electrochemically introduced into the porous structure of the: waveguide core. The doping profiles of erbium and ytterbium ions were determined by EDX analysis performed on sample cross-section. The mean concentration in the guiding layer is of about 1 x 10(20) cm(-3) The refractive indices were measured from co-doped porous silicon and undoped waveguides after the thermal treatments. The photoluminescence (PL) peak of optically activated erbium ions at 1.53 mu m was recorded. The PL enhancement is the result of the energy transfer from the excited state of Yb to the state of Er. Optical losses at 1.55 mu m were measured on these waveguides and were of about 2 dB/cm. An internal gain at 1.53 mu m of 5.8 dB/cm has been measured with a pump power of 65 mW at 980 nm. (C) 2007 Published by Elsevier B.V.