摘要
基于Drude模型,采用解析法与数值模拟法研究了具有电与磁非线性效应超常介质中光束的聚焦特性。结果表明超常材料中光束聚焦现象不但可以发生在自聚焦非线性介质中(正折射区)而且可以发生在自散焦非线性介质中(负折射区),且光束中心频率离介质的等离子频率越近,其聚焦效应越明显。特别是当电与磁非线性极化率为异号时,超常介质的非线性符号可以通过调控电与磁等离子频率的相对大小控制,这为主动操控光束的传输提供一种新的自由度。
Based on the Drude mode,beam focusing in metamaterials with both electric and magnetic nonlinearities are investigated,both analytically and numerically.The results show that beam focusing occurs not only in self-focusing nonlinear materials（positive-index region）,but also in self-defocusing nonlinear material（negative-index region）.In addition,the self-focusing effect is stronger when the plasma frequency of the material shifts closer to the central frequency of the beam.In particular,when the signs for electric and magnetic susceptibilities are different,the sign of nonlinearity for metamaterials can be engineered by varying the relative magnitude between electric and the magnetic plasma frequencies.This provides us an alternative approach to manipulate beam propagation at will.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2010年第8期1745-1750,共6页
High Power Laser and Particle Beams
基金
国家自然科学基金项目(10974049)
关键词
非线性光学
超常介质
自聚焦
光束传输
nonlinear optics
metamaterials
self-focusing
beam propagation
