Integrable all-optics NOT gate using nonlinear photonic crystal MZI for photonic integrated circuit

摘要

A silicon photonic crystal (PhC)-based nonlinear Mach-Zehnder interferometer (NMZI) is used to design a new model for an all-optical NOT gate. The nonlinear arm of the NMZI is considered to be made of a slotted-PhC waveguide, where the slot is filled with silicon nanocrystal (SiNC/SiO2) material. The high nonlinearity of the SiNC/SiO2 and low group velocity of the PhC make it possible to attain a significant phase shift in low-power high-frequency pulses traveling through the nonlinear arm. A control wave is utilized to increase the phase shift by the cross-phase modulation phenomenon. A complete study on the phase variation is performed by varying various parameters such as powers and pulse widths of the probe and control signal. The study is used to determine the length of the nonlinear arm to calculate the transfer characteristic of the device. The transfer characteristic shows a successful inversion operation in the power range of 28-60 mW for a pulse width of 3 ps. The overall dimension of the device is found as approximate to 112 x 7 mu m(2). Tolerances of the device performance under fabrication imperfections are analyzed by allowing random variations in the positions and the radii of the holes. This study reveals that the inversion characteristic is sustained, even for the significant fabrication imperfections. (C) 2020 Optical Society of America