All-optical Majority and Feynman gates in photonic crystals

In this paper we propose, for the first time, all-optical Majority and Feynman gates in two-dimensional silicon photonic crystals. Photonic crystals are optical semiconductor nanodevices, formed by a periodicity in one, two or three dimensions in the refractive index of a macroscopic media. These devices can operate with low power consumption, high speed and low dissipation of energy to heat. A photonic crystal waveguide is a perfect platform to accomplish the design of all-optical devices. The functionality of logic gates proposed here is achieved due to the light beam interference effect. For the Majority gate, the simulation results show that the transmission to define logic 0 is less than 35% and logic 1 greater than 85%. In addition, for the Feynman gate the transmission to define logic 0 and logic 1 are ≤10% and ≥ 40%, respectively. In order to perform the simulations we applied the FDTD method in the MEEP software package. The Majority and Feynman logic devices presented here can be potential candidates for the realization of low power photonic computational circuits.