  We present plasmonic Bragg reflectors for increasing the extraordinary
optical transmission through periodic arrays of subwavelength apertures in a
metal film. The increase in transmission arises by preventing loss at the edges
of the array. The plasmonic Bragg reflectors have periodicity of half the usual
array's periodicity. Nano-hole arrays flanked thus by reflectors exchibited
double the transmission as compared to the arrays without reflectors. These
structures may also be used to isolate devices in plasmonic integrated
circuits.
