MODELING OF YB3+-SENSITIZED ER3+-DOPED SILICA WAVE-GUIDE AMPLIFIERS

A model for Yb3+ sensitized Er3+-doped silica waveguide amplifiers is described and numerically investigated in the small-signal regime. The amplified spontaneous emission in the ytterbium-band and the quenching process between excited erbium ions are included in the model. For pump wavelengths between 860 and 995 mn, the amplified spontaneous emission in the ytterbium-band is found to reduce both the gain and the optimum length of the amplifier significantly. The achievable gain of the Yb3+-sensitized amplifier is found to be higher than in an Er3+-doped silica waveguide without Yb3+ (18 dB versus 9 dB for a pump power of 100 mW). However, it is important to optimize the Yb-concentration according to the choice of pump wavelength.