圆形周期介质内艾里光束的传输特性

为了研究无衍射光波在特异材质内的传输特性,实现更优良的光波通信,将传统右手材料和双负折射率材料相结合,提出了一种轴向阶跃变化周期圆形介质结构。基于广义惠更斯-菲涅耳光学积分公式,结合光学传输矩阵,分析了艾里光束在这种传输媒质中出射表面光强分布特性和侧面传输光强分布图;分析了负折射率参量对这类光波演变的影响及其补偿机理;分析了实现输出光波完美还原时,负折射率大小同介质单元长度的定量关系。结果表明,当介质孔径逐渐减小时,有限艾里光束衍射效应越来越严重,并且出射光强外形轮廓逐渐从艾里光束过渡到高斯光束;当双负折射率材料的折射率n_l的绝对值大于右手材料的折射率n_r时,出射表面实现光波完美还原的双负折射率材料单元层越长,反之则越短。该研究对分析周期或准周期轴向阶跃变化的圆形平板介质光波通信是有帮助的。

Characteristics of Airy beam propagating in circular periodic media

In order to study the propagation characteristics of non-diffracting light waves in special materials and achieve better optical communication, one periodic circular dielectric structure with axial step change was proposed by combining traditional right-handed materials with bi-negative refractive index materials. Based on the generalized Huygens-Fresnel optical integral formula, the distribution characteristics of the emitted surface light intensity and the profile of the side light intensity of the Airy beam in this transmission medium were analyzed by using optical transmission matrix. The influence of negative refractive index parameters on the evolution of such light waves and its compensation mechanism were analyzed. The quantitative relationship between the negative refractive index and the length of the dielectric unit was analyzed when the output light wave was perfectly restored. The results show that, when the pore size of the medium decreases gradually, the diffraction effect of finite Airy beam is getting worse and worse. The profile of the emitted light intensity gradually transits from the Airy beam to the Gaussian beam. When the absolute value of n_l is greater than n_r, the bi-negative refractive index material layer is longer when the perfect light wave reduction is achieved on the exit surface. Conversely, the shorter. The study is helpful for analyzing optical wave communication in circular flat dielectrics with periodic or quasi-periodic axial step changes.