title: Electro-optic light modulation and THz generation in locally plasma-activated silicon nanophotonic devices.
abstract: 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.
authors.forename: Christopher
authors.initials: C
authors.lastname: Matheisen
authors.forename: Michael
authors.initials: M
authors.lastname: Waldow
authors.forename: Bartos
authors.initials: B
authors.lastname: Chmielak
authors.forename: Simon
authors.initials: S
authors.lastname: Sawallich
authors.forename: Thorsten
authors.initials: T
authors.lastname: Wahlbrink
authors.forename: Jens
authors.initials: J
authors.lastname: Bolten
authors.forename: Michael
authors.initials: M
authors.lastname: Nagel
authors.forename: Heinrich
authors.initials: H
authors.lastname: Kurz