Optical study of Erbium-doped-porous silicon based planar waveguides

Planar waveguides were formed from porous silicon layers obtained on P⁺ substrates. These waveguides were then doped by erbium using an electrochemical method. Erbium concentration in the range 2.2-2.5 at% was determined by energy dispersive X-ray (EDX) analysis performed on SEM cross sections. The refractive index of layers was studied before and after doping and thermal treatments. The photoluminescence of Er³⁺ ions in the IR range and the decay curve of the 1.53 μm emission peak were studied as a function of the excitation power. The value of excited Er density was equal to 0.07%. Optical loss contributions were analyzed on these waveguides and the losses were equal to 1.1 dB/cm at 1.55 μm after doping.