Conforti Matteo
Opt Lett. 2014 Apr 15;39(8):2427-30. doi: 10.1364/OL.39.002427.
The evolution of light pulses and beams in a quasi-phase-matched (QPM) quadratic medium is usually described by considering only the spatial harmonic of the QPM grating that minimizes the residual phase-mismatch. I show that, for strongly phase-mismatched interactions (the cascading regime), several harmonics need to be accounted for in order to obtain the correct value of the effective cubic nonlinearity, for which I find a simple analytical expression. I discuss the effects of the higher order harmonics of the grating on solitary wave propagation.
在准相位匹配（QPM）二次介质中，光脉冲和光束的演化通常仅通过考虑使残余相位失配最小化的QPM光栅的空间谐波来描述。我表明，对于强相位失配相互作用（级联 regime），为了获得有效三次非线性的正确值，需要考虑几个谐波，为此我找到了一个简单的解析表达式。我讨论了光栅高阶谐波对孤波传播的影响。
