Re-Configurable Optical XNOR to XOR Gate Based on Silicon Microring Resonator

In this paper, we present an innovative electrooptic reconfigurable gate capable of transitioning between two operational modes: functioning as an XNOR gate and as an XOR gate. Our design incorporates three silicon microring resonators (MRRs) arranged in parallel within the arms of a Mach–Zehnder interferometric (MZI) structure. Specifically, MRR C is linked to the upper arm of the MZI and can be externally controlled. When MRR C is in resonance condition, the gate operates as an XNOR gate, and when MRR C is out of resonance condition, it functions as an XOR gate. The microring resonators employ an electrooptic modulation technique relying on carrier injection, where a voltage of 2 V corresponds to logic 1, while −1.85 V represents logic 0. To comprehensively demonstrate the gate's performance, we conducted time-domain simulations. The XNOR operation attained an extinction ratio (ER) measuring 6.5 dB, while the XOR operation yielded an ER of 8.5 dB, respectively.