掺镱光纤放大器(YDFA)特性的研究

Studies of ytterbium-doped fiber amplifiers

根据二能级近似模型 ,在忽略光纤损耗和放大自发辐射 (ASE)的条件 ,引入光场与掺杂分布的重叠因子 ,得到掺镱光纤放大器 (YD FA)中速率、传输方程的解析解 ,在此基础上得到了放大器增益的解析表达式、阈值泵浦功率表达式和小信号下最佳光纤长度表达式 ,并利用数值模拟结果对放大器的增益、泵浦阈值、最佳光纤长度进行分析和讨论。

Based on two-level model,analytical solutions have been derived for rate and light propagation equations after introducing the overlapping factors between the light intensities and the ytterbium dopant distributions inside the fiber core and excluding the effects of fiber spoilage and ASE process.The gain analytical expression、pump threshold expression and the optimum fiber length expression of a small signal are deduced.Using the numerical simulations,gain、pump threshold power and the optimum fiber length of the amplifiers have been analysed and discussed.