Design of a Compact Logic Device Based on Plasmon-Induced Transparency

Optical logic device is an important part of optical computing. In this letter, we investigate a novel and compact logic device based on plasmon-induced transparency (PIT). This device consists of a pair of hexagonal ring resonators coupled with two parallel metal-insulator-metal (MIM) waveguides. According to the temporal coupled-mode theory, the appropriate detuning between the resonance wavelengths of two resonators act as the key factor to achieve the PIT. The finite-difference time-domain simulations reveal that by changing the refractive index, logic states 1 and 0 which are represented by the high and low levels of the optical power can be achieved at the through and drop port. So the proposed structure can implement the function of logical operations XOR and XNOR simultaneously. This device is suitable for on-chip optical computing, and it may provide a new way for the realization of plasmonic logic device.