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arXiv · 2604.08472

High-efficiency graphene-silicon slot-waveguide microring modulator at 1.5 μm and 2 μm wavelength bands

Chao Luan·Deming Kong·Yong Liu·Yunhong Ding·Hao Hu
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Abstract

Electro-optic (E/O) modulators are crucial for optical communication but face a trade-off between modulation bandwidth and efficiency. A small footprint could reduce the capacitance and increase the bandwidth, however, this usually results in a low modulation efficiency. Here, we present an integrated E/O modulator that simultaneously achieves wideband large bandwidth and high modu- lation efficiency operation by embedding a partially overlapped double-layer graphene on a compact silicon slot waveguide microring resonator. At 1550 nm, the graphene-silicon slot-waveguide demon- strates a high phase modulation efficiency of Vπ L = 220 V μm, and the corresponding microring modulator has a large bandwidth of over 70 GHz, a compact active length of 10 μm, and an optical modulation amplitude (OMA) of -1.97 dBm under a 3-V voltage swing. The modulator operates at a data rate of 50 Gbit/s with an open eye diagram under a 2-V Vpp RF drive voltage. The graphene modulator operation is broadband, and we also characterize its performance at 2 μm wavelength band. At 2 μm wavelength band, the microring modulator has a large bandwidth of over 20 GHz, an OMA of -3.36 dBm under a 6-V voltage swing, and an open eye diagram at 20 Gbit/s with a 2-V Vpp RF drive voltage. The difference in performance is caused by the bandwidth limit of the 2 μm wavelength band measurement setup. The broadband, large bandwidth, compact, highly effi- cient, and energy efficient graphene E/O modulator has the potential to enable large-scale graphene photonic integrated circuits, facilitating a broad range of applications such as optical interconnects, optical neural networks, and programmable photonic circuits.

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Chao Luan, Deming Kong, Yong Liu, Yunhong Ding, Hao Hu. 2026-04-09. High-efficiency graphene-silicon slot-waveguide microring modulator at 1.5 μm and 2 μm wavelength bands. https://arxiv.org/abs/2604.08472

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