摘要
为了得到分辨率更好的平板透镜,利用有限元的方法研究了由水/水银材料组合的二维蜂窝结构声子晶体平板透镜的负折射成像特性,通过数值仿真计算了声子晶体的能带结构、等频色散曲线,模拟了点源成像,并且利用高斯波束验证了声子晶体平板透镜的负折射现象,得到了有效折射率neff=-1的成像。对比相同材料的正方晶格和三角晶格而言,该模型的成像效果更佳。为了改善成像分辨率,还在原来的模型上进行了改进,得到了分辨率约为0.37λ的亚波长像。
To get a superior imaging resolution, a flat len of two-dimensional phononic crystal （PC） with honeycomb-lattice, which is composed of water/mercury, was studied by finite-element method. The band structure and equifrequency contour （EFC） of the PC were calculated and the Gaussian beam was used to demonstrate the negative refraction effects of the PC len. It is found that the effective index of -1 could be obtained by simulation with a point source. As contrasted to square-lattice and triangular-lattice with these same materials, the better effects of imaging and a dominant resolution can be gotten with honeycomb- lattice. In order to improve the imaging resolution, a new model based on the old one was presented with a subwavelength imaging resolution of 0.37λ.
出处
《应用声学》
CSCD
北大核心
2015年第6期533-538,共6页
Journal of Applied Acoustics
基金
广东省自然科学基金重点项目(S2012020010885)
广东省科技计划项目(2012b01010036)
关键词
声子晶体
负折射
蜂窝结构
成像
Phononic crystal, Negative refraction, Honeycomb-lattice, Imaging
