Resonator channel drop filters in a plasmon-polaritons metal

Channel drop filters with ring/disk resonators in a plasmon-polaritons metal are studied. It shows that light can be efficiently dropped. Results obtained by the finite difference time domain method are consistent with those from the coupled mode theory. It also shows, without considering the loss of the metal, that the quality factor for the channel drop system can be very high. The quality factor decreases significantly if we take into account the loss, which also leads to a weak drop efficiency. (c) 2006 Optical Society of America.