Design and performance analysis of MMI based all optical logic gates on SOI substrate

We propose MMI based all optical logic gates which are used for various logic functions. The input signal is considered as logical `0' or `1' according to phase of the signal and the output of a device is depend upon the intensity of light i.e. low intensity means `0' and high intensity means `1'. Hence the propose device is used to convert input phase information to amplitude information at the output port. The proposed MMI structure has ultracompact dimension of 2.5 μm × 10.6 μm that can be used in Photonics integrated circuits. We have used Beam propagation method to analyze the performance of the device. Simulation results show that the ON-OFF extinction ratio of OR, NAND, XOR, XNOR, and NOT optical logic gates are 18.5, 18.5, 20.1, 20.1 and 20.1 dB respectively in whole C-band.