Design and analysis of all optical 2D Photonic crystals based full subtractor

The all-optical subtractor is a crucial component of optical computation. In this paper, an all-optical full subtractor using 2-dimensional photonic crystals has been proposed and designed. The proposed structure operates on the principle of the interference method and it is simulated using the Finite-Difference Time-Domain (FDTD) method. To analyze the structure, we have determined the contrast ratio and amplitude modulation. The contrast ratio (CR) is 28.24 dB and the amplitude modulation (AM) is 0.504 dB for the Difference output, while for the Borrow output of the full subtractor, the CR is 27.70 dB and the AM is 0.88 dB. The advantages of the structure are low response time ( 0.094ps), high bit rate speed (10.66 Tb/s) and smaller footprint area (196.31 µm2) .