ECE PhD Thesis Defense: Mete Aslan

ECE PhD Thesis Defense: Mete Aslan

Title: A Spatially Uniform Light Source and Its Applications in Imaging and Biosensing

Presenter: Mete Aslan

Advisor: Professor Selim Ünlü

Chair: Professor Rabia Yazicigil

Committee: Professor Selim Ünlü, Professor Irving Bigio, Professor Anna Swan, Professor Tianyu Wang

Google Scholar Link: https://scholar.google.com/citations?user=xGz5IysAAAAJ&hl=en

Abstract: Illumination quality is of paramount importance for optical microscopy. Especially in quantitative optical microscopy, the accurate characterization of the sample relies on even excitation, and any heterogeneity in the excitation can result in quantification errors. While existing software-based corrections attempt to mitigate these issues, they consume substantial computational power and often introduce reconstruction artifacts that degrade data fidelity. On the other hand, current hardware solutions typically require complex multi-element optical trains or are optimized for their design wavelength, hindering the development of a universal platform for spectrally and spatially uniform illumination. This thesis introduces a novel universal illuminator, the Efficient Uniform Color Light Integration Source (EUCLID), which addresses these limitations. Leveraging a diffusive hollow conical cavity based on the principles of integrating spheres, EUCLID homogeneously integrates multiple light inputs, both coherent and incoherent, to deliver multi-spectral output through a single port. Its unique conical geometry is specifically optimized for high-power delivery and efficient coupling to finite-NA systems.

Beyond the hardware architecture, this work demonstrates several multi-parametric imaging and detection techniques enabled by the EUCLID platform. Using two-color Multi-Parametric Interferometric Reflectance Imaging Sensing (MP-IRIS), the precise quantification of molecular interactions is demonstrated while effectively eliminating bulk effects. Furthermore, high-sensitivity single-particle detection methods, including Spectral Pixel-Diversity IRIS (PD-IRIS) for the detection of MPOX viral particles within 20 minutes, which is critical for point-of-care (POC) diagnostics, and Polarization PD-IRIS for high-level multiplexing in POC applications are showcased. Finally, the thesis proposes a high-throughput well-plate reader enabled by EUCLID designed for centralized laboratory use. Collectively, these advancements establish EUCLID as a versatile and robust solution for standardizing and enhancing the precision of next-generation optical sensing and diagnostic platforms.