Nonlinear light beam propagation in uniaxial crystals: nonlinear refractive index, self-trapping and self-focusing
Nonlinear light beam propagation in uniaxial crystals: nonlinear refractive index, self-trapping and self-focusing
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DOI：
10.1088/1464-4258/2/1/302
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发表时间：
2000
影响因子：
2.1
通讯作者：
Q. Guo;S. Chi
中科院分区：
文献类型：
--
作者：
Q. Guo;S. Chi
推导了光束在具有中心对称的各向异性非线性介质中传输的非线性近轴波动方程。作为方程的应用，我们得到了三种单轴晶体的非线性折射率(NRI)，它们分别属于六方晶系的6/mm对称级、四方晶系的4/mmm对称级和三角晶系的m对称级，并考虑了光束在这些晶体中任意方向传播时的自陷和自聚焦。我们得出结论：对于非常光，NRI、临界功率和自聚焦长度都是各向异性的(取决于传输方向)，而对于普通光则是各向同性的；对于非常光，存在椭圆自陷光束。
We derive the nonlinear paraxial wave equation for the propagation of an optical beam in nonlinear anisotropic media with centrosymmetry. As an application of the equation, we obtain the nonlinear refractive index (NRI) in three uniaxial crystals belonging to the symmetry classes 6/mmm of the hexagonal system, 4/mmm of the tetragonal system, and m of the trigonal system, respectively, and consider the self-trapping and self-focusing of the beam propagating in any direction in these crystals. We conclude that NRI, critical power and self-focusing length are all anisotropic (dependent upon the propagation direction) for an extraordinary light but isotropic for an ordinary light, and that there exists an elliptical self-trapping beam for the extraordinary light.