Zhao Li-Ming, Yue Gui-Kuan, Zhou Yun-Song, Wang Fu-He
Center of Theoretical Physics, Department of Physics, Capital Normal University, Beijing 100048, China.
Opt Express. 2013 Jul 29;21(15):17592-601. doi: 10.1364/OE.21.017592.
Second harmonic generation (SHG) from the aperiodic optical superlattice (AOS) in considering the pump depletion is investigated. It is found the domain configuration designed in undepleted pump approximation (UPA) can also be used to achieve multiple wavelength SHGs with high enough conversion efficiency for an exact solution. The applicable scope of UPA was estimated by a relative tolerance based on the related SHG conversion efficiency calculated in UPA and an exact solution. Results reveal that the relative tolerance is solely determined by the conversion efficiency, and unrelated to the sample configuration, pump intensity, incidental wavelength and nonlinear media. A model to evaluate an exact solution is proposed, and it is suggested that the SHG conversion efficiency can be easily assessed by the developed model. These results can be used to provide direct guidance for practical application, and can also make the estimation of practical samples more convenient.
研究了考虑泵浦损耗时非周期光学超晶格（AOS）的二次谐波产生（SHG）。发现未耗尽泵浦近似（UPA）中设计的畴结构也可用于实现多波长SHG，对于精确解具有足够高的转换效率。基于UPA中计算的相关SHG转换效率和精确解，通过相对容差估计了UPA的适用范围。结果表明，相对容差仅由转换效率决定，与样品结构、泵浦强度、入射波长和非线性介质无关。提出了一个评估精确解的模型，并表明通过所开发的模型可以轻松评估SHG转换效率。这些结果可为实际应用提供直接指导，也可使实际样品的估计更加方便。
