  A powerful analytical approach is followed to study light transmission
through subwavelength holes drilled in thick perfect-conductor films, showing
that full transmission (100%) is attainable in arrays of arbitrarily narrow
holes as compared to the film thickness. The interplay between resonances
localized in individual holes and lattice resonances originating in the array
periodicity reveals new mechanisms of transmission enhancement and suppression.
In particular, localized resonances obtained by filling the holes with
high-index-of-refraction material are examined and experimentally observed
through large enhancement in the transmission of individual holes.
