CAN MAXWELLʹS FISH EYE LENS REALLY GIVE PERFECT IMAGING? PART II. THE CASE WITH PASSIVE DRAINS

We use both FEM (finite element method) and FDTD (finite difference time domain method) to simulate the field distribution in Maxwellʹs fish eye lens with one or more passive drains around the image point. We use the same Maxwellʹs fish eye lens structure as the one used in recent microwave experiment [arXiv:1007.2530]: Maxwellʹs fish eye lens bounded by PEC (perfect electric conductor) is inserted between two parallel PEC plates (as a waveguide structure). Our simulation results indicate that if one uses an active coaxial cable as the object and set an array of passive drains around the image region, what one obtains is not an image of the object but only multiple spots resembling the array of passive drains. The resolution of Maxwellʹs fish eye is finite even with such passive drains at the image locations. We also found that the subwavelength spot around the passive drain is due to the local field enhancement of the metal tip of the drain rather than the fish eye medium or the ability of the drain in extracting waves.