Loschialpo P F, Smith D L, Forester D W, Rachford F J, Schelleng J
Naval Research Laboratory, Washington, D.C. 20375, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Feb;67(2 Pt 2):025602. doi: 10.1103/PhysRevE.67.025602. Epub 2003 Feb 26.
We demonstrate that negative refraction occurs for both cw and pulsed electromagnetic waves when traversing from a "right-handed" (index > 0) to a "left-handed" (index < 0) material (LHM) which has causal dispersive intrinsic properties. We also demonstrate that a divergent line source spaced a distance H in front of a planar LHM slab and excited by either an impulse cw or a Gaussian frequency pulse is imaged at a distance H away, inside the LHM, and at H to the other side of the slab. The image size is approximately lambda consistent with limitations dictated by wave optics. We find no evidence of evanescent mode amplification. The studies were performed using numerical experiments with finite difference time domain solutions and incorporating a causal Lorentzian form for the frequency-dependent material properties.
我们证明，当连续波（cw）和脉冲电磁波从具有因果色散本征特性的“右手性”（折射率>0）材料穿越到“左手性”（折射率<0）材料（左手材料，LHM）时，会发生负折射。我们还证明，在平面左手材料平板前方距离H处有一个发散线源，由脉冲连续波或高斯频率脉冲激发，该线源会在左手材料内部距离平板另一侧H处成像。图像尺寸约为波长λ，这与波动光学所规定的限制相符。我们没有发现倏逝模放大的证据。这些研究是通过有限差分时域解的数值实验进行的，并采用了频率相关材料特性的因果洛伦兹形式。
