Simulation and Demonstration of Directed XOR/XNOR Logic Gates Using Two Cascaded Microring Resonators

Yonghui Tian,Jianhong Yang,Xiaoping Gao,Yongpeng Zhao,Dezhao Li,Zilong Liu,Guolin Zhao,Huifu Xiao,Genliang Han

doi:10.1109/jphot.2016.2535910

Abstract

We propose and demonstrate a directed optical logic circuit that can perform the XOR and XNOR logic operations consisting of two cascaded microring resonators, i.e., an upper waveguide and an under waveguide. No waveguide crossings exist in the circuit, which is very useful to improve the signal quality and reduce the insertion loss of the device. As proof of principle, XOR and XNOR logic operations with the speed of 10 kb/s are successfully demonstrated. In addition, numerical simulation results indicate that the length difference between the upper waveguide and the under waveguide can change the output spectrum characteristics of the device, which acts like a Mach–Zehnder interferometer (MZI).

Highlights

Optical information processing has attracted intensive attention over the past few decades due to its unique advantages of high speed, low power consumption, potentially improved security, and parallel processing [1]–[6]
Continuous wave output from amplified spontaneous emission source (ASE) is coupled into the device by a lensed fiber, and two tunable voltages are applied to two micro-heaters to modulate Microring resonator (MRR) through the thermo-optic effect
When the voltages applied to MRR1 and MRR2 are 1.44 and 0 V, the optical wave at ! is downloaded by both MRR1 and MRR2; there is a sharp peak in the spectrum, which means the optical power is at the high level at !, and a logic 1 is obtained at the Through port [see Fig. 3(a), A 1⁄4 0, B 1⁄4 0]

Summary

Introduction

Optical information processing has attracted intensive attention over the past few decades due to its unique advantages of high speed, low power consumption, potentially improved security, and parallel processing [1]–[6]. Compared with electrical information processing, optical information processing is a most promising scheme at large amounts of data in real time domain. Microring resonator (MRR) is a critical building block for optical information processing due to its unique advantages such as low consumption, compact size, and large-scale integration. It is widely used in on-chip optical information processing [12], [13]. Directed logic is an innovative logic paradigm that employs the electrical pulse sequences

Results

Discussion

Conclusion