采用传输矩阵法和时域有限差分(FDTD)法, 对基于人工介质的低通空间滤波器的传输特性进行了数值模拟和分析, 提出了两种具体的设计方案,得到了控制空间滤波器截止波矢的方法。数值计算结果表明,利用不确定介质或低有效折射率光子晶体都可实现高性能的低通空间滤波。两种滤波器都由薄平板构成,所占的空间体积只有几个波长量级,可大大减少传统空间滤波器所占的空间体积。

By using the transfer matrix method and finite difference time domain (FDTD) method, the propagation characteristics of artificial media based low-pass spatial filters were numerically simulated and analyzed. Two schemes were presented, and the method controlling the cutoff wave-vector of the spatial filters was obtained. Numerical calculations show that spatial filtering utilizing the indefinite metamaterial or low effective index photonic crystal processes near filed components and is inherent compact. It consists of multilayer of thin slabs, which are only a few wavelengths thick. The spatial filters based on the artificially media is significant in the high-power laser, which can decrease the spaces occupied by the conventional spatial filters.