Application of self-collimated beams in realizing all-optical photonic crystal-based half-adder

In this paper an all-optical half-adder was proposed by using self-collimation effect in two-dimensional photonic crystals. Self-collimation effect was obtained in XM direction for wavelength 1500nm by using square lattice rod-type photonic crystal structure. Plane wave expansion and finite-difference time-domain methods were used to obtain the band structure diagram and simulate the optical behavior of the proposed structure, respectively. The maximum delay time and required input intensity are 1ps and 54mW/m(2), respectively. The normalized power-level margins for logics 0 and 1 were obtained to be about 20 and 70%, respectively. The total footprint of the structure is about 75m(2), which is suitable for all optical integrated circuits.