【摘要】 在均匀准相位匹配(QPM )光栅中引入非π相移,拓宽了基于周期反转型铌酸锂波导(PPLN )差频(DFG)波长转换器的泵浦带宽.应用调制函数的概念描述了引入相移后的QPM光栅,得到一个比较简单的计算转换效率的解析表达式.数值计算了引入两个相移域和四个相移域的QPM光栅,并解释了引入相移后带宽加宽的机理.模拟结果表明采用非π相移的方法比采用π相移的方法在转换效率没有太大下降的情况下,带宽得到明显改善.更多还原

【Abstract】 Pump bandwidth enhancement of periodically poled LiNbO₃ （PPLN）-based difference frequency generation （DFG） wavelength conversion by introducing various distributing formats of non π-phase shifting domains into the quasi-phase-matching （QPM） gratings was demonstrated. A simple analytic expression of conversion efficiency was obtained by using a modulation function to describe an aperiodic QPM gratings. The QPM gratings with two phase shifting domains and four phase shifting domains were numerically calculated, and the mechanism of the bandwidth enhancement was explained. The numerical simulation results show that introducing non π-phase shifting domains enhances pump bandwidth much more than just introducing π-phase shifting domains, while the conversion efficiency decreases very little.更多还原