Affiliation:
1. China University of Geosciences
2. Optics Valley Laboratory
3. Xidian University
Abstract
High-performance germanium photodiodes are crucial components in silicon photonic integrated circuits for large-capacity data communication. However, the bandwidths of most germanium photodiodes are limited by the intractable resistance–capacitance parasitic effect. Here, we introduce a unique U-shaped electrode to alleviate this issue, reducing the parasitic effect by 36% without compromising any other performance. Experimentally, a large bandwidth of 103 GHz, an optical responsivity of 0.95 A/W at 1550 nm, and a dark current as low as 1.3 nA are achieved, leading to a record high specific detectivity. This is the first breakthrough to 100 GHz bandwidth among all vertical germanium photodiodes, to the best of our knowledge. Open eye diagrams of 120 Gb/s on-off keying and 200 Gb/s four-level pulse amplitude signals are well received. This work provides a promising solution for chip-based ultra-fast photodetection.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Key Research and Development Program of Hubei Province
Innovation Project of Optics Valley Laboratory
Program for HUST Academic Frontier Youth Team
Subject
Atomic and Molecular Physics, and Optics,Electronic, Optical and Magnetic Materials