Numerical analysis of all optical 1-bit comparator based on PhC structure for optical integrated circuits

We propose an all optical 1-bit comparator design based on the two dimensional (2D) photonic crystal ring resonator (PhCRR) coupled to six optical waveguides. The two-dimensional finite difference time domain (2D-FDTD) method is utilized for the numerical investigation and optical properties of the proposed structures. The time response diagram shows that there is a contrast ratio as 9.85 dB between the normalized output power in the logical “1” and “0” states at the wavelength of 1550 nm. The footprint and time delay of this optical device are 318 m^2 and 1.5ps, respectively which represent ultra-fast and ultra-compact structure. Therefore, the presented optical comparator is a promising candidate for use in optical integrated circuits.