Design and simulation of all-optical majority gates using fluid infiltration approach in photonic crystal slab

With the growth of technology and the need to integrate optical devices, photonic crystals (PhCs) will have great potential in designing and fabricating programmable photonic integrated circuits (PICs). This paper proposes two all-optical majority gates using the fluid infiltration approach in a PhC slab, which aims to design logic functions. Numerical results using the well-known plane wave expansion method show that the proposed fundamental PhC slab has three photonic band gaps (PBGs) in TE mode. The most important is in the wavelength range of 1.516 mu m <= lambda <= 1.743 mu m, located in the attractive telecom C-band range. The results of light propagation inside the proposed gates using the finite-difference time-domain (FDTD) method reveal that both gates have a standard threshold of less than 0.28 for the logic zero and more than 0.35 for the logic one. The first and second proposed majority gates also have delays of 680 fs and 610 fs, respectively. One of the advantages of using the fluid infiltration approach is that there is no need to change the geometric dimensions of the structure for the desired application. That goal can be achieved only by replacing the fluid with another one. The proposed designs can be used as basic logic gates in the design of PICs.