基于SOA中FWM效应实现全光波长变换

A Study on All Optical Wavelength Conversion Based on SOA-FWM

基于半导体光放大器的四波混频 FWM(Four- Wave Mixing)型波长变换技术发展前景最好 ,但由于半导体光放大器的自发辐射噪声 ,导致输出信噪比劣化。如果利用非线性耦合波方程推导出变换光信噪比的表达式 ,分析影响信噪比的参数 ,对于一定的输入信号光 ,较大的泵浦光就有利于提高变换光信噪比 ,大的偏置电流和小的频差可以改善信噪比 ,对优化设计 SOA- FWM波长变换器具有一定的参考价值。

Wavelength conversion is one of the key techniques in all optical networks.Although the optically transparent wavelength conversion technique based on four-wave mixing in semiconductor optical amplifiers has good prospect in the future networks,the output signal to noise ratio (SNR) is degenerated due to amplified spontaneous emission noise of semiconductor optical amplifier.The theory of four-wave mixing in semiconductor optical amplifiers is investigated in this study,and the formula of output SNR is derived from nonlinear coupled wave equation.The parameters of affecting SNR are analyzed by formular,and are studied by photonic software emulation system. The effects for SNR by input pump power,bias current and pump-signal detuning in frequency are analyzed.The results show for a given signal power level and high pump power level is beneficial for increasing output SNR.Big bias current and small pump-signal detuning in frequency can improve output SNR.The studying results set the consulted value on optimization of SOA-FWM wavelength converters designing.