Optical amplification in Er3+-doped P2O5-SiO2 planar waveguides

The small signal gain of Er3+-doped P2O5-SiO2 planar waveguides is described with a homogeneous upconversion model. The homogeneous upconversion process accurately describes the absorption saturation at a wavelength of 0.98 mu m. Interpretation of the absorption saturation provides homogeneous upconversion coefficients of 4x10(-15) cm(3) s(-1) for a 0.54 wt % Er3+-doped 14.6 wt % P2O5 codoped silica waveguide and 6x10(-18) cm(3) s(-1) for a 0.46 wt % Er3+-doped 21.6. wt % P2O5 codoped silica waveguide. The upconversion process occurs in the Er3+ ion rich phase in the P2O5-SiO2 core glass. A calculation that includes the homogeneous upconversion process proves that the gain can be enhanced by codoping the planar waveguide with P2O5. A gain of 20 dB is calculated with an Er3+ ion concentration of 0.4-0.7 wt % and a waveguide length of 40 cm when the pump power is 100 mW and 20 wt % P2O5 codoped Er3+-doped silica-based planar waveguides are used. (C) 1996 American Institute of Physics.