A new design procedure for all-optical photonic crystal logic gates and functions based on threshold logic

In this paper, a general method is proposed to design all-optical photonic crystal logic gates and functions based on threshold logic concept that have regular pattern in inputs. In our proposed structure, a photonic crystal junction is cascaded by a threshold power level detector. Additionally, a novel mechanism is introduced to shift the threshold power level for designing different logic gates and functions. The finite difference time domain and plane wave expansion methods are used to evaluate the proposed structures. The proposed gates and functions occupy an area less than 150 µm2 and also, the maximum power required for the switching mechanism is 15 µW. The inputs and output in the mentioned gates and functions are homogeneous and they can operate with a bit rate of about 500 Gbits/s.