Electro-optic directed logic circuit based on microring resonators for XOR/XNOR operations

Lei Zhang,Yonghui Tian,Lin Yang,Rui Min,Weiwei Zhu,Yangyang Lu,Jianfeng Ding,Hongtao Chen,Ruiqiang Ji,Ping Zhou

doi:10.1364/oe.20.011605

Abstract

We report the implementation of the XOR and XNOR operations using an electro-optic directed logic circuit based on two cascaded silicon microring resonators (MRRs), which are both modulated through the plasma dispersion effect. PIN diodes are embedded around the MRRs to achieve the carrier-injection modulation. The inherent resonance wavelength mismatch between the two nominally identical MRRs caused by fabrication errors is compensated by two local microheaters above each MRR through the thermo-optic effect. Two electrical modulating signals applied to the MRRs represent the two operands of the two operations. Simultaneous bitwise XOR and XNOR operations at 100 Mbit/s are demonstrated.

Highlights

With the shrinking of transistors and metal interconnects, the power-consumption and transmission-bandwidth limitations of silicon electronics have been approached [1,2,3]
The fabricated device is characterized by an amplified spontaneous emission (ASE) source, an optical spectrum analyzer (OSA) and a tunable voltage source
The response spectra at the two output ports of the device are shown in Fig. 3, with MRR2 being tuned by a heating voltage of 2.92 V to align the resonance wavelengths of the two microring resonators (MRRs)

Summary

Introduction

With the shrinking of transistors and metal interconnects, the power-consumption and transmission-bandwidth limitations of silicon electronics have been approached [1,2,3]. It has been widely regarded as a means for keeping on track with Moore’s Law by using optical interconnects to provide faster data transfer both between and within microchips [1,2,3]. For this purpose, various optical components have been developed such as the laser sources [7], electro-optic modulators [8], photodetectors [9], as well as the optical routers for networks-on-chips (NoC) [10, 11]. The XOR/XNOR operations are carried out correctly at 100 Mbit/s in both the degenerate and non-degenerate regions

Design and fabrication

Experimental results

The first operating mode: working in the non-degenerate region

Conclusion