Zhang C, Zhu Y Y, Yang S X, Qin Y Q, Zhu S N, Chen Y B, Liu H, Ming N B
Opt Lett. 2000 Apr 1;25(7):436-8. doi: 10.1364/ol.25.000436.
Coupling of optical parametric processes in an optical superlattice through quadratic nonlinearity was analyzed theoretically. Solving the coupled equations, we found that efficient quasi-phase-matched third-harmonic (TH) generation depends not only on the magnitude of the coupling coefficients but also on their ratio. Theoretically, all the fundamental energy can be transferred to the TH at a particular ratio. In other cases, there exists an optimum condition that corresponds to a maximum TH conversion efficiency. The result is of practical importance for the design of TH devices.
从理论上分析了光学超晶格中通过二次非线性实现的光学参量过程的耦合。通过求解耦合方程，我们发现高效的准相位匹配三次谐波（TH）产生不仅取决于耦合系数的大小，还取决于它们的比值。理论上，在特定比值下，所有基波能量都可以转移到三次谐波上。在其他情况下，存在一个对应于最大三次谐波转换效率的最佳条件。该结果对于三次谐波器件的设计具有实际重要性。
