Abstract:In this study, we design and numerically investigate a novel all optical D flip-flop (AODFF) based on linear photonic crystal (LPhC) structure that is composed of optical waveguides using the finite difference time domain method. The proposed structure has the hexagonal close packed of 16 × 20 circular rods that is suspended in the air substrate with a lattice constant of 606 nm. The plane wave expansion method is used to obtain the band diagram for AODFF at an operating wavelength of 1550 nm. The proposed optical flip-flop achieves a low delay time of 0.2ps and a high contrast ratio of 10.33dB. The main advantage of this design is that low input power as low as 1mW/μm2 is sufficient for its operation, since no nonlinear rods are included. In addition, the footprint of the proposed AODFF is 100 μm2, which is smaller compared to the structures reported in the literature, and it has a fast switching frequency of 5Tbit/s.