Realization of all-optical three-person voting function based on self-collimation with the two-dimensional photonic crystals

•The sturcture is simple with two line defects in two-dimensional PCs.•We present the structure of ultra-compactness in size.•The proposed three-person voter has high light contrast ratio.

In the paper, a simple structure of three-person voting circuit is proposed and based on self-collimation effect with the two-dimensional photonic crystals. The electric field intensity of the proposed structure is deduced according to optical interference theory. The results show that the simple structure with two-dimensional photonic crystals can realize the three-person voting either from the optical interference theory or simulation, meanwhile, the light contrast ratio between the output logic signal “1” and “0” can reach as high as 19 dB. When compared with three-person voting designed with digital electronic technology, the size of the proposed design in this paper is more smaller, which is valuable in photonic device integration and compactness.