复宗量高斯光束通过左手材料的传输特性研究

发布时间：2019-01-21 08:21

【摘要】：左手介质与常规介质不同,它为物理学发展开创了一片新的领域。当电磁波通过左手介质时,会出现很多奇异的现象,如负折射效应、逆Doppler效应等。近年来,左手介质在光学、材料科学、电磁学等领域引起了诸多关注。因此,研究光束通过左手材料(LHM)的传输特性具有重要意义。本学位论文主要对复宗量双曲余弦平方-高斯光束(EchSGB)和双曲正弦平方-高斯光束(ShSGB)通过平板LHM的传输特性进行研究。基于广义惠更斯-菲涅尔衍射积分推导出EchSGB和ShSGB在自由空间、平板LHM内部和通过平板LHM后的三维光强传输公式,采用二阶矩定义推导了EchSGB和ShSGB的光斑尺寸、束腰宽度、束腰位置、2M因子的解析表达式,并对其进行数值计算和分析。研究表明:1.EchSGB的束腰宽度只受与复宗量双曲余弦平方因子相关的参数a、b影响,光斑尺寸、束腰位置以及2M因子还会受到LHM负折射率Ln的影响,材料的负折射率改变光束分布的位置,参数a、b改变光束的形状和大小。当计算取特殊值时,LHM能使EchSGB重现。因此,实际运用中,可以选取较小参数值的EchSGB通过较大负折射率的LHM,获取质量更好的光束,同时还可通过改变光束参数a、b以及LHM负折射率Ln的大小在不同位置对该光束整形。2.LHM对ShSGB轴上光强和横向光强分布规律的影响是使光强呈对称分布;材料的负折射率会影响光束轴上光强极大值的位置,轴上光强和横向光强的分布均随传输距离和参数?的变化而变化,?是与双曲正弦平方因子相关的参数;束腰宽度只与参数?有关,轴上光强、横向光强、光斑尺寸、束腰位置、2M因子还会受LHM影响;较小的参数?值和较大的负折射率绝对值都使得2M因子的值变小,即光束质量更好。此外,还可通过改变光束参数?以及LHM负折射率Ln的大小在不同位置对ShSGB整形。
[Abstract]:The left-handed medium is different from the conventional medium, it opens a new field for the development of physics. When the electromagnetic wave passes through the left-handed medium, there are many strange phenomena, such as negative refraction effect, inverse Doppler effect and so on. In recent years, left-handed medium has attracted much attention in optics, material science, electromagnetism and other fields. Therefore, it is of great significance to study the propagation characteristics of the beam through the left-handed material (LHM). In this dissertation, the propagation characteristics of the hyperbolic cosine squared Gao Si beam (EchSGB) and the hyperbolic sinusoidal square-Gao Si beam (ShSGB) through the plate LHM are studied. Based on the generalized Huygens-Fresnel diffraction integral, the three dimensional light intensity propagation formulas of EchSGB and ShSGB are derived in free space, inside the plate LHM and after passing through the plate LHM. The size of the spot and the width of the beam waist of EchSGB and ShSGB are derived by the second moment definition. The analytical expression of the waist position and the 2 M factor is calculated and analyzed numerically. The results show that the beam waist width of 1.EchSGB is only affected by the parameter ab related to the complex hyperbolic cosine squared factor, and the spot size, beam waist position and 2m factor are also affected by the negative refractive index Ln of LHM. The negative refractive index of the material changes the position of the beam distribution and the parameter ab changes the shape and size of the beam. When a special value is calculated, LHM can reproduce the EchSGB. Therefore, in practical application, the EchSGB with smaller parameter values can be selected to obtain better beam quality through LHM, with larger negative refractive index, and the beam parameter a can be changed at the same time. B and the magnitude of LHM negative refractive index Ln at different positions to shape the beam. The influence of 2.LHM on the distribution of light intensity and transverse intensity on the ShSGB axis is that the light intensity is symmetrically distributed. The negative refractive index of the material will affect the position of the maximum of the light intensity on the beam axis, and the distribution of the intensity of light on the axis and the distribution of the transverse intensity are both with the propagation distance and the parameters. Change and change,? Is a parameter related to the squared factor of the hyperbolic sinusoidal; the waist width of the beam is related only to the parameter? The light intensity on axis, transverse light intensity, spot size, waist position and 2m factor will also be affected by LHM. Both the value of negative refractive index and the absolute value of negative refractive index make the value of 2m factor smaller, that is, the beam quality is better. In addition, by changing beam parameters? And the size of LHM negative refractive index Ln in different positions for ShSGB shaping.
【学位授予单位】：四川师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O436

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