High Performance Ge Devices for Electronic-Photonic Integrated Circuits

Abstract

We present high performance, Ge-based photodetectors and electro-absorption (EA) modulators for electronic-photonic integrated circuits on Si platform. As a pseudo-direct band gap material, Ge offers excellent optoelectronic properties with CMOS compatibility. We demonstrate waveguide-integrated Ge photodetectors with a high responsivity of >1.0 A/W in a broad spectrum range of 1470-1570 nm and >7 GHz bandwidth at a low reverse bias of -0.1 V. We have also achieved a waveguide-integrated, ultra-low energy GeSi EA modulator with a small footprint of 30 µm2, a 10 dB extinction ratio at 1540 nm, an ultra-low energy consumption of 50 fJ/bit, and an operation spectrum that covers half of the C-band. These devices have been fabricated with standard CMOS technology and can be conveniently integrated with CMOS circuits for electronic-photonic integration.