Open AccessHigh performance, waveguide integrated Ge photodetectors
Author(s) -
Donghwan Ahn,
Ching-yin Hong,
Jifeng Liu,
Wojciech Giziewicz,
Mark Beals,
Lionel C. Kimerling,
Jürgen Michel,
Jian Chen,
Franz X. Kärtner
Publication year - 2007
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.15.003916
Subject(s) - photodetector , optoelectronics , responsivity , materials science , cmos , photonics , waveguide , capacitance , integrated circuit , photonic integrated circuit , dark current , photodiode , silicon photonics , optics , physics , electrode , quantum mechanics
Photonic systems based on complementary metal oxide semiconductor (CMOS) technology require the integration of passive and active photonic devices. The integration of waveguides and photodetector is one of the most important technologies. We report a Ge p-i-n photodetector that is monolithically integrated with silicon oxynitride and silicon nitride waveguides. All processes and materials are CMOS compatible and can be implemented in the current integrated circuit process technology. The small size of the devices results in low absolute dark current. The waveguidecoupled Ge devices show high efficiency (~90%) over a wide range of wavelengths well beyond the direct band gap of Ge, resulting in a responsivity of 1.08 A/W for 1550 nm light. The device speed of 7.2 GHz at 1V reverse bias is strongly affected by the capacitance of the probe pads. The high-performance of the devices at low voltage ( </= 1V) facilitates the integration with CMOS circuits.