【摘要】 对大口径、高功率情况下的三次谐波转换 ,选择 KDP晶体 Type / Type 匹配角度失谐的三倍频方案 ,并从非线性三波耦合方程组出发 ,采用离散傅立叶变换和四阶龙格 -库塔 ( R-K)积分方法 ,编制了二维模拟三次谐波转换的计算程序。计算了各种晶体厚度和不同失谐角条件下 ,二、三次谐波的转换特性和效率。并对入射基频光为六阶超高斯分布时的三倍频器进行了优化 ,三倍频转换效率达80 % ,此时具有较大的动态范围和较高的三倍频转换效率更多还原

【Abstract】 Type Ⅰ/ Type Ⅱ angle-detunin g tripling frequency scheme of KDP crystal was chose for triple harmonic conversio n with large aperture and high power. Based on three-wave mixing nonlinear coup ling equation, wrote a two-dimension program for numerical simulation triple ha rmonic conversion by introducing discrete Fourier transform and a fourth-order Runge-Kutta integrating method. With the code, conversion features and efficien cies of second and third harmonics were calculated with different thickness of c rystal and different angle-detuning. Tripling frequency system assuming that th e intensity distribution of 1ω is super Gaussian distribution with sixth-o rder is optimized. The results showed that the system has both broad dynamic ran ge and more high conversion efficiency.更多还原