We use both FEM (finite element method) and FDTD (finite difference time domain method) to simulate the field distribution in Maxwell's fish eye lens with one or more passive drains around the image point. We use the same Maxwell's fish eye lens structure as the one used in recent microwave experiment [arXiv:1007.2530]: Maxwell's 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 Maxwell's 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.
2. Luneburg, R. K., Mathematical Theory of Optics, University of California Press, Berkeley, CA, 1964.
3. Born, M. and E.Wolf, Principles of Optics, 5 Ed., Pergamon, Oxford, 1975.
4. Leonhardt, U., "Perfect imaging without negative refraction," New J. Phys., Vol. 11, 093040-093051, 2009.
5. Leonhardt, U. and T. G. Philbin, "Perfect imaging with positive refraction in three dimensions," Phys. Rev. A, Vol. 81, 011804, 2010.
6. Blaikie, R. J., "Comment on `Perfect imaging without negative refraction'," New Journal of Physics, Vol. 12, 058001, 2010.
7. Leonhardt, U., "Reply to comment on `Perfect imaging without negative refraction'," New Journal of Physics, Vol. 12, 058002, 2010.
8. Guenneau, S., A. Diatta, and R. C. McPhedran, "Focusing: Coming to the point in metamaterials," Journal of Modern Optics, Vol. 57, No. 7, 511-527, 2010.
9. Sun, F. and S. He, "Can Maxwell's fish eye lens really give perfect imaging?," Progress In Electromagnetics Research, Vol. 108, 307-322, 2010.
10. Ma, Y. G., C. K. Ong, S. Sahebdivan, T. Tyc, and U. Leonhardt, "Perfect imaging without negative refraction for microwaves,", arXiv:1007.2530.
11. Jackson, J. D., Classical Electrodynamics, 3 Ed., John Wiley and Sons, 1998.
12. Gabrielli, L. H., U. Leonhardt, and M. Lipson, "Perfect imaging in the optical domain using dielectric materials,", arXiv:1007.2564.