一维金属-介质周期结构的自准直特性和亚波长成像

计算了一维金属-介质周期结构(1DMD)的色散曲线，利用传输矩阵法模拟了该结构对入射高斯光束的自准直作用，着重讨论了金属层吸收的影响；对该结构在半波长厚度时近场成像特性进行了分析，单光源的成像分辨率为λ/8，达到亚波长分辨效果；分辨率随着光源逐渐远离近场范围而降低. 双狭缝的成像模拟进一步验证了1DMD结构的近场亚波长成像能力，分辨率达到λ/3.

Analysis of self-collimation and subwavelength imaging in one-dimensional metal-dielectric structure

The dispersion curve of one-dimensional metal-dielectric structure is calculated, and the finite-difference time-domain (FDTD) method is used to simulate the self-collimation in one-dimensional metal-dielectric structure, to which a Gaussian beam is incident at different angles. The influence of the dissipation of the metal layer on self-collimation is discussed. Subwavelength imaing with the one-dimensional metal-dielectric structure is also analyzed. The resolution of λ/8 is achieved for single point source when the thickness of 1DMD is equal to λ/2. The resolution will gradually degrade as the source moves beyond the near-field domain. Imaging with double slits source is also demonstrated, and a resolution of λ/3 is achieved.