AbstractIn the constant-intensity approximation, we analyze the nonlinear quasiphase-matched frequency doubling and tripling in the case of a backward second-harmonic wave. The third harmonic conversion efficiency for different orders of the quasiphase matching is analytically calculated. We show that there exists an optimum value of the ratio of nonlinear coefficients (β₃/β₂)_opt and find that the conversion maximum η₃ = 0.12 is reached at (β₃/β₂)_opt = 0.667, which is consistent with the result of the numerical calculation. Also we provide recommendations for designing optical superlattices from new prospective materials for efficient frequency converters.

中文翻译：

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光学超晶格在后向二次谐波波中的连续三波混合

摘要在等强度近似中，我们分析了在向后二次谐波情况下非线性准相位匹配的倍频和三倍频。分析计算了不同阶准相位匹配的三次谐波转换效率。我们表明，存在非线性系数的比率的最佳值（β ₃ /β ₂）_选择之后，如果发现转换最大η ₃ = 0 。在（达到12 β ₃ /β ₂）_选择= 0 。667，与数值计算结果一致。此外，我们还提供了有关使用新型预期材料设计光学超晶格的建议，以实现高效的变频器。