【摘要】 以衍射理论为基础,建立了椭偏高斯光束通过非线性介质后远场光强分布的理论模型。利用该理论模型采用数值模拟的方法研究了椭偏高斯光束与非线性介质相互作用后在远场形成的衍射图样随椭偏光椭偏率变化的演化规律。分析发现,在不同非线性机制下,椭偏率的变化对远场衍射图样的影响明显不同。在分子取向机制下,非线性介质对入射椭偏高斯光束椭偏率变化的响应最敏感,不仅影响衍射图样的分布尺寸和衍射环的数目,而且还影响远场衍射图样中央光斑的亮暗。由于线偏振和圆偏振是椭圆偏振的特殊情况,本文所建立的模型也适用于入射光束偏振态为线偏振或圆偏振态的情况。更多还原

【Abstract】 Based on the diffraction theory,a theoretical model of far-field intensity distribution of elliptically polarized Gaussian beam passing through the nonlinear medium was established.Using this theoretical model,the effect of the ellipticity of elliptically polarized Gaussian beam on the evolution of the far-field pattern was studied.The results show that the influence of the ellipticity on far-field diffraction patterns is different for different nonlinear mechanisms.For the molecular reorientation mechanism,the influence of the change of the ellipticity on the far-field pattern is the biggest,which will not only change the diameter of the pattern and the number of diffraction rings,but also change the spot of the pattern from dark to bright(or from bright to dark).In addition,the theoretical model is also applicable to the cases where the polarization state of the incident Gaussian beam is linearly polarized or circularly polarized.更多还原