梯度负折射率介质中高斯光束传输特性的研究  

Propagation properties of Gaussian beam in gradient negative index of refraction material

作　　者：周建华[1] 李栋华[1] 曾阳素[1] 朱鸿鹏[1] 

机构地区：[1]邵阳学院信息工程系,激光与信息技术研究所,邵阳422000

出　　处：《物理学报》2014年第10期143-149,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:11247296)资助的课题~~

摘　　要：导出了高斯光束在梯度负折射率介质中的ABCD矩阵,据此得到光束在此介质中的传输模型.并利用此模型分析了高斯光束在梯度负折射率介质中的传输特性,发现它能产生空间孤子及呼吸子形式的传输,并发现光束的束腰半径不一定是最小束宽半径.还研究了梯度系数对介质聚焦能力的影响,据此可以设计出相应聚焦能力所需要的折射率分布.最后分析了传输时高斯光束曲率半径的变化情况,与光束束宽半径的变化显著不同,曲率半径始终从无穷大开始,然后产生一个个周期性的变换.We apply the ABCD formalism to a gradient negative index medium （NIM） and investigate the propagation and transformation properties of Gaussian beams in this medium. First, we derive the ABCD formalism in a positive gradient NIM and obtain the propagation model. Spatial soliton and the spatial breather propagation in this medium are revealed. Our research suggests that the gradient coefficient has a significant effect on the focusing ability of slab. When the gradient coefficient increases, the quasi-lense effect becomes more prominent and notable. As a result, the focusing ability improves and the beam waist in the focal point shrinks. Second, when Gaussian beams propagate in the negative gradient NIM, the beam waist enlarges as the distance increases. There is neither spatial soliton phenomenon nor breather transmission phenomenon, which is completely different from the propagation characteristics in the positive gradient NIM.

关 键 词：高斯光束 梯度负折射率介质 ABCD定律 传输特性 

分 类 号：O435.1[机械工程—光学工程]