Public defence in Micro- and nanosciences, M.Sc. Dura Shahwar

The title of the thesis: Polarization management in silicon photonics

Thesis defender: Dura Shahwar
Opponent: Prof. Roel Baets, Ghent University, Belgium
Custos: Prof. Zhipei Sun, Aalto University School of Electrical Engineering

Modern technological progress is increasingly driven by the integration of electronic and photonic functionalities on compact platforms. While photonic integrated circuits (PICs) have enabled significant advances in communication, sensing, and signal processing, their widespread adoption is often limited by polarization-dependent behavior. Many photonic components exhibit sensitivity to the state of polarization of light, which can degrade system performance, reduce efficiency, and impose design constraints. Effective on-chip polarization management is therefore essential to advancing the scalability and reliability of integrated photonic systems. This thesis investigates novel concepts and device architectures that address key challenges in polarization control for silicon photonics. Several component designs are proposed and experimentally demonstrated, supported by theoretical analysis, numerical modelling, and characterization. 

In parallel, a comprehensive review of polarization management techniques is presented, outlining the current state of the field and identifying promising directions for future development. This research for low-loss PICs for polarization management applications has the potential to support development in areas such as digital infrastructure, secure communication and compact solutions. In telecommunications, for instance, polarization management enables more reliable and faster optical data transmission, supporting the infrastructure behind public internet access and digital public services. The research results will be utilized in many applications, including medical imaging, where the low-loss properties and polarization management allow for miniaturization and integration of photonics-based systems.

Thesis available for public display 7 days prior to the defence at Aaltodoc.