为了从系统的角度研究大气湍流对涡旋光束传播质量的影响,根据广义惠更斯-菲涅尔积分和Kolmogorov湍流大气原理,利用傅里叶光学分析方法和光束分步传播法对携带有轨道角动量(OAM)的拉盖尔-高斯(LG)光束在湍流大气中的传播进行理论分析...为了从系统的角度研究大气湍流对涡旋光束传播质量的影响,根据广义惠更斯-菲涅尔积分和Kolmogorov湍流大气原理,利用傅里叶光学分析方法和光束分步传播法对携带有轨道角动量(OAM)的拉盖尔-高斯(LG)光束在湍流大气中的传播进行理论分析与数值仿真,导出角谱形式的衍射模型及其对应的抽样限制条件。利用桶中功率(PIB,power in bucket)计算方法,分析湍流强度对不同OAM值的LG光束质量的影响;引入高斯光束和点光源,对比评估典型光束的抗湍流能力。数值仿真结果表明:受大气湍流影响,随着LG光束在湍流大气中传播距离增加,光束会聚能力变弱有明显扩散;光束本身特有的环状光强分布及其相应的相位分布都受到不同程度的破坏,损伤程度与光束本身携带的OAM数有关;点光源对湍流的影响最为敏感;高斯光束具有与小OAM值的LG光束相比拟的抗湍流能力,且比大OAM数的LG光束有更强的抗湍流能力。展开更多
Although there are many reports on the resonant absorption and the second harmonic of laser plasma in recent years, these phenomena were treated individually and no study on their interaction has been carried out. We ...Although there are many reports on the resonant absorption and the second harmonic of laser plasma in recent years, these phenomena were treated individually and no study on their interaction has been carried out. We used a Nd: glass laser (3—6 Joules, 100 ps pulses) to irradiate plane aluminium targets with a power density of —1015 W/cm2 on the tartar surface.展开更多
文摘为了从系统的角度研究大气湍流对涡旋光束传播质量的影响,根据广义惠更斯-菲涅尔积分和Kolmogorov湍流大气原理,利用傅里叶光学分析方法和光束分步传播法对携带有轨道角动量(OAM)的拉盖尔-高斯(LG)光束在湍流大气中的传播进行理论分析与数值仿真,导出角谱形式的衍射模型及其对应的抽样限制条件。利用桶中功率(PIB,power in bucket)计算方法,分析湍流强度对不同OAM值的LG光束质量的影响;引入高斯光束和点光源,对比评估典型光束的抗湍流能力。数值仿真结果表明:受大气湍流影响,随着LG光束在湍流大气中传播距离增加,光束会聚能力变弱有明显扩散;光束本身特有的环状光强分布及其相应的相位分布都受到不同程度的破坏,损伤程度与光束本身携带的OAM数有关;点光源对湍流的影响最为敏感;高斯光束具有与小OAM值的LG光束相比拟的抗湍流能力,且比大OAM数的LG光束有更强的抗湍流能力。
文摘Although there are many reports on the resonant absorption and the second harmonic of laser plasma in recent years, these phenomena were treated individually and no study on their interaction has been carried out. We used a Nd: glass laser (3—6 Joules, 100 ps pulses) to irradiate plane aluminium targets with a power density of —1015 W/cm2 on the tartar surface.