Graphene Electro-Absorption Modulators for Energy-Efficient and High-Speed Optical Transceivers

The increasing demand for energy-efficient hardware for artificial intelligence (AI) and data centres requires integrated photonic solutions delivering optical transceivers with Tbit/s data rates and energy consumption<1pJ/bit. Here, we report double single-layer graphene electro-absorption modulators on Si optimized for energy-efficient and ultra-fast operation, demonstrating 67GHz bandwidth and 80Gbit/s data rate, in both O and C bands, using a fabrication tailored for wafer-scale integration. We measure a data rate∼1.6 times larger than previously reported for graphene. We scale the modulator’s active area down to 22μm ² , achieving a dynamic power consumption∼58fJ/bit, ∼3 times lower than previous graphene modulators and Mach-Zehnder modulators based on Si or lithium niobate. We show devices with∼0.037dB/Vμm modulation efficiency,∼16 times better than previous demonstrations based on graphene. This paves the way to wafer-scale production of graphene modulators on Si useful for Tbit/s optical transceivers and energy-efficient AI.