The interactions of silver nanorings with polarized optical wave are numerically studied. If the resonant conditions are
tuned, the polarization of incident field, inside the nanoring hole, will be reversed by the single silver nanoring due to the
surface plasmon resonance, thus, the nanoring hole becomes a region of which permittivity is negative. Put two identical
silver nanorings closely, there are two nodes happened between nanorings. It indicates that there is a very steep gradient
of electric field and quasi-standing waves exist between nanorings. If many silver nanorings are lined up, the holes of the
nanorings will form a negative permittivity chamber. The more close to the center of the chamber, the more ideal the
polarization is reversed.