Date of Award
2026
Document Type
Doctoral Thesis
Degree Name
Doctor of Philosophy
Department
Physical Sciences
First Advisor
William Whelan-Curtin
Second Advisor
Ganga Chinna Rao Devarapu
Abstract
Testing in the field of photonics, particularly for photonic devices, is a critical step that ensures the reliability and performance of these sophisticated components. Photonic integrated circuits (PICs), which are at the heart of many modern optical systems, require rigorous testing to validate their functionality and efficiency. This thesis investigates sophisticated testing methods for various nanophotonic devices on platforms like Silicon, Silicon Nitride, Silicon Germanium and Lithium Niobate. It starts by introducing the fundamental tools and processes involved in fabricating these devices. The study then provides a detailed theoretical understanding of different devices, including Photonic Crystal (PhC) cavities, grating couplers and Fabry-Perot cavity. A significant part of the research is dedicated to die level testing of PhC cavities and the development of a wafer-level testing platform. This is achieved using Resonant Scattering Spectroscopy, showcasing its potential for broader applications such as critical dimension measurements and commercial viability due to its non-invasive and high-throughput characteristics. In addition, a study examines vertical coupling schemes on Silicon and Silicon Nitride platforms, vital for efficient coupling between waveguides and PhC cavities. The research also further pioneers in the modelling, design, and fabrication of grating couplers on the Silicon Germanium platform, marking a first in the mid-infrared domain. Another notable contribution is the exploration of Micro-transfer Printing as an advanced technique to realize hybrid integration which is first of its kind. Overall, this work makes significant contributions to the testing and application of nanophotonic devices, paving the way for future research and development in the field.
Recommended Citation
Ananthachar, Adarsh, "Advanced Optical Coupling and Testing Techniques for Silicon, Silicon Nitride, Silicon Germanium and Lithium Niobate Nanophotonic Devices" (2026). Theses [online].
Available at: https://doi.org/10.34719/s6g2-a011
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Access Level
info:eu-repo/semantics/openAccess