Design of Compact Integrated Photonic Crystal NAND and NOR Logic Gates

Here we propose an integrated and compact photonic crystal (PhC) device that can operate as a NAND or NOR logic gate. It is designed in a PhC slab composed of GaAs/AlGaAs heterostructure and a 2D pattern of a triangular lattice of holes. By modifying target holes on the structure, the NAND or NOR gates are achieved. They are universal logic functions, which means that any logic function can be accomplished by connecting them. We perform simulations through the FDTD method to prove the correct operation of our integrated and compact device. The simulation results show that the upper power limit to represent the logic 0 is 0.17P(in), where P-in is the input power. On the other hand, the lower power limit to represent the logic 1 is found to be 0.50P(in). The NAND and NOR logic gates implemented here present a response time of 5 ps, resulting in a clock rate of 200 GHz. They also operate within the C band of the telecommunication window. Finally, we highlight that our integrated and compact PhC device has great potential to be microfabricated as it is based on a practical and efficient approach for fabrication. It also can be incorporated easily on integrated photonics technology.