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Original Research ARTICLE Provisionally accepted The full-text will be published soon. Notify me

Front. Phys. | doi: 10.3389/fphy.2019.00104

Field-induced nonlinearities in silicon waveguides embedded in lateral p-n junctions

  • 1NanoLab, Department of Physics, University of Trento, Italy
  • 2Fondazione Bruno Kessler, Italy

Silicon waveguides embedded in lateral p-n junctions show field-induced optical nonlinearities. By properly polarizing the junction, these can be used to achieve electro-optic modulation through the Direct Current Kerr effect. In addition, these enable second-order nonlinear processes such as the electric-field-induced second harmonic generation (EFISHG). In this work, we study in detail electro-optic effects in integrated silicon microresonators and demonstrate experimentally a field-induced resonance wavelength shift. This process is due to both the DC Kerr effect and the plasma-dispersion effect. By means of finite element method simulations, these effects are properly modeled and their contributions are accurately disentangled. The strength of the equivalent second-order nonlinear coefficient that would have provided the same electro-optic effect is about 16 pm/V. This result is comparable with that of materials possessing an intrinsic second order nonlinearity, and is one order of magnitude stronger than the most recent measurements of strain-induced Pockels effect in silicon.

Keywords: Nonlinear optics, silicon photonics, Kerr effect, field-induced nonlineatiries, Plasma-dispersion effect, p-n junctions, microring resonator

Received: 20 May 2019; Accepted: 05 Jul 2019.

Edited by:

Shinichi Saito, University of Southampton, United Kingdom

Reviewed by:

Junichi Fujikata, Photonics Electronics Technology Research Association, Japan
Isao Tomita, Department of Electrical and Computer Engineering, National Institute of Technology, Gifu College, Japan  

Copyright: © 2019 Castellan, Franchi, Biasi, Bernard, Ghulinyan and Pavesi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Dr. Claudio Castellan, NanoLab, Department of Physics, University of Trento, Trento, 38123, Trentino-Alto Adige/Südtirol, Italy, claudiocastellan233@gmail.com