Accurate modeling of left-handed media using finite-difference time-domain method and finite-size effects of a left-handed medium slab on the image quality revisited

摘要

The letter contains an important message regarding the numerical modeling ofleft-handed media (LHM) using the finite-difference time-domain (FDTD) methodwhich remains at the moment one of the main techniques used in studies of theseexotic materials. It is shown that conventional implementation of thedispersive FDTD method leads to inaccurate description of evanescent waves inthe LHM. This defect can be corrected using the spatial averaging at theinterfaces. However, a number of results obtained using conventional FDTDmethod has to be reconsidered. For instance, the accurate simulation ofsub-wavelength imaging by the finite-sized slabs of left-handed media does notreveal the cavity effect reported in [Phys. Rev. Lett. 92, 107404 (2004)].Hence the finite transverse dimension of LHM slabs does not have significanteffects on the sub-wavelength image quality, in contrary to previousassertions.