Open AccessElectro-optic light modulation and THz generation in locally plasma-activated silicon nanophotonic devices
Author(s) -
Christopher Matheisen,
Michael Waldow,
Bartos Chmielak,
Simon Sawallich,
T. Wahlbrink,
Jens Bolten,
M. Nagel,
H. Kurz
Publication year - 2014
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.005252
Subject(s) - nanophotonics , materials science , optics , optoelectronics , silicon , nonlinear optics , terahertz radiation , physics , laser
Silicon is not an electro-optic material by itself but the required second-order optical nonlinearity can be induced by breaking the inversion symmetry of the crystal lattice. Recently, an attractive approach has been demonstrated based on a surface-activation in a CMOS-compatible HBr dry etching process. In this work, we further investigate and quantify the second-order nonlinearity induced by this process. Using THz near-field probing we demonstrate that this simple and versatile process can be applied to locally equip silicon nanophotonic chips with micro-scale areas of electro-optic activity. The realization of a first fully integrated Mach-Zehnder modulator device - based on this process - is applied to quantify the nonlinearity to an effective χ((2)) of 9 ± 1 pm/V. Analysis of the thermal stability of the induced nonlinearity reveals post-processing limitations and paths for further efficiency improvements.