40 Gbps hexagonal 16QAM using silicon microrings for green optical interconnects: modeling and performance study

This article presents a comprehensive study of a proposed 40 Gbps hexagonal 16QAM modulator based on four silicon microring modulators (MRMs), demonstrating enhanced performance over classical modulation formats. The MRMs, with a ring length of 53.8 μm and a coupling ratio (κ) of 0.2, enable precise optical signal modulation via voltage control. The hexagonal constellation design offers equidistant symbol placement, resulting in improved symbol detection margins and lower bit error rates (BER). Mathematical modeling and constellation analysis confirm the benefits of the hexagonal structure, achieving a BER of 10−3 at 16.5 dB OSNR. Validated through theoretical analysis and simulation, this green photonic modulator demonstrates robustness and reliability for noise-tolerant optical communication, paving the way for high-efficiency, low-power optical systems.