80Gb/s NRZ Ge waveguide electro-absorption modulator

We demonstrate a Ge electro-absorption modulator (EAM) in L band with a 3 dB electro-optical bandwidth beyond 67 GHz at -3 V bias voltage. The Eye diagram measurement shows a data rate of over 80 Gbps for non-return-to-zero on-off keying (NRZ-OOK) modulation at a voltage swing of 2.3V(pp) and the wavelength of 1605 nm. Through the comparison of multi-device results, it is proved that the introduction of the annealing process after CMP can increase the mean static extinction ratio of the EAM from 7.27 dB to 11.83 dB, which confirms the manufacturability of the device. The dynamic power consumption of the device is 6.348 fJ/bit. The performance of our device is comprehensive. The Ge EAM device also has excellent performance as a photodetector (PD) in the C and L communication bands. The responsivity of the device is 1.04 A/W at the wavelength of 1610 nm, resulting in similar to 0.87 mW of static power consumption at -3V bias voltage under 0.28 mW of optical input and the 3 dB opto-electric bandwidth of the devices are beyond 43 GHz at -3V bias. (c) 2022 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement

Automated summary

This study demonstrates a Ge electro-absorption modulator (EAM) in the L band with a 3 dB electro-optical bandwidth beyond 67 GHz. The device achieves a data rate of over 80 Gbps for non-return-to-zero on-off keying (NRZ-OOK) modulation at a voltage swing of 2.3V(pp) and a wavelength of 1605 nm. The introduction of an annealing process after CMP is proven to increase the mean static extinction ratio of the EAM, confirming its manufacturability.