Experiments on Glide-Symmetric Photonic-Crystal Waveguides

Publikation: Bog/antologi/afhandling/rapportPh.d.-afhandlingForskning

  • Chirag Murendranath Patil
This thesis is intended to report the research outcome of the fabrication and characterization of glide-symmetry photonic-crystal waveguides on a silicon-on-insulator (SOI) platform. The glide-symmetry waveguide has the potential to offer new functionalities in the realm of chiral quantum-optics. These waveguides can support circularly polarized light, which is important for observing chiral behavior. Additionally, the presence of a band-crossing at the Brillouin-zone edge offers an interesting feature. Silicon is a promising substrate for fabricating both active and passive nanophotonic devices, and has a huge potential for building photonic integrated-circuits. An optimized recipe to fabricate photonic-crystal waveguides on SOI platform has be en described. Major challenges and drawbacks have been investigated and reported. The final devices are optically characterized and measured to study the various properties of the photonic-crystal waveguides. A free-space optics characterization setup is built to perform transmission measurements on resonators and photonic circuits. Measurements are performed on morethan 150 devices for statistical averaging on an ensemble of photonic-crystal waveguides. From the glide-symmetry waveguide resonator design, slow-light phenomenon is observed, the group index is extracted and its implications are discussed. A combination of slow-light and transmission over band-crossing in photonic-crystal latticespresents an opportunity to investigate interesting features. Further, a novel criterion to qualitatively measure the localization length is also proposed. Localization length is a key parameter to detect the onset of Anderson localization in disordered systems. The Thouless criterion clearly distinguishes localized and non-localized modes by making a connection between fluctuations inconductance with localization. This criterion is explored and combined with systematic variation of sample size to extract the localization length in a simplified manner. This method is further verified experimentally for two different variations of photonic-crystal waveguide
OriginalsprogEngelsk
ForlagNiels Bohr Institute, Faculty of Science, University of Copenhagen
StatusUdgivet - 2020

ID: 239960915