Integrated Optics Devices|2 Article(s)
Mode selection and dispersion engineering in Bragg-like slot photonic crystal waveguides for hybrid light–matter interactions
Samuel Serna, Weiwei Zhang, Thi Hong Cam Hoang, Carlos Alonso-Ramos, Delphine Marris-Morini, Laurent Vivien, and Eric Cassan
We introduce a family of slot photonic crystal waveguides (SPhCWs) for the hybrid integration of low-index active materials in silicon photonics with energy-confinement factors of ~30% in low-index regions. The proposed approach, which is based on a periodic indentation of the etched slot in the middle of the SPhCW, makes it possible to reconcile a simultaneously narrow and wide slot for exploiting the two modes of even symmetry of a SPhCW. The resulting mode-selection mechanism allows a flexible choice of the modes to be used. Furthermore, the proposed structure offers tremendous flexibility for adjusting the dispersive properties of the slot-confined modes, in particular of their slow-light effects. Flat band slow light in a bandwidth of about 60 nm with a group velocity dispersion factor |β2| below 1 ps2/mm is numerically demonstrated by this approach, corresponding to a normalized delay bandwidth product of around 0.4. These results, obtained from hollow-core periodic waveguides that are directly designed in view of hybrid integration of active materials in mechanically robust structures (not based on free-standing membranes) could pave the way for the realization of on-chip slow-light bio-sensing, active hybrid-silicon optoelectronic devices, or all-optical hybrid-silicon nonlinear functionalities.
Photonics Research
  • Publication Date: Jan. 01, 2018
  • Vol. 6, Issue 1, 01000054 (2018)