• DOI:10.1515/nanoph-2019-0153
• Corpus ID: 198902430

Coupling-enhanced dual ITO layer electro-absorption modulator in silicon photonics

@article{Tahersima2019CouplingenhancedDI,
  title={Coupling-enhanced dual ITO layer electro-absorption modulator in silicon photonics},
  author={Mohammad H. Tahersima and Zhizhen Ma and Yaliang Gui and Shuai Sun and Hao Wang and Rubab Amin and Hamed Dalir and Ray T. Chen and Mario Miscuglio and Volker J. Sorger},
  journal={Nanophotonics},
  year={2019},
  volume={8},
  pages={1559 - 1566}
}

• Mohammad H. Tahersima, Zhizhen Ma, +7 authors V. Sorger
• Published 28 May 2019
• Physics
• Nanophotonics

Abstract Electro-optic signal modulation provides a key functionality in modern technology and information networks. Photonic integration has not only enabled miniaturizing photonic components, but also provided performance improvements due to co-design addressing both electrical and optical device rules. The millimeter to centimeter footprint of many foundry-ready electro-optic modulators, however, limits density scaling of on-chip photonic systems. To address these limitations, here we experimentally demonstrate a coupling-enhanced electro-absorption modulator by heterogeneously integrating a novel dual-gated indium-tin-oxide phase-shifting tunable absorber placed at a silicon directional coupler region. This concept allows utilizing the normally parasitic Kramers-Kronig relations here in an synergistic way resulting in a strong modulation depth to insertion loss ratio of about 1. Our experimental modulator shows a 2 dB extinction ratio for a just 4 μm short device at 4 V bias. Since no optical resonances are deployed, this device shows spectrally broadband operation as demonstrated here across the entire C-band. In conclusion, we demonstrate a modulator utilizing strong index change from both real and imaginary parts of active material enabling compact and high-performing modulators using semiconductor near-foundry materials.