ECE PhD Thesis Defense: Jiabei Zhu

ECE PhD Thesis Defense: Jiabei Zhu

Title: Advancing intensity diffraction tomography with multiple scattering models in transmission and reflection systems

Presenter: Jiabei Zhu

Advisor: Professor Lei Tian

Chair: Professor Ji-Xin Cheng

Committee: Professor Lei Tian, Professor Luca Dal Negro, Professor Michelle Sander, and Professor Ulugbek Kamilov.

Google Scholar Link: https://scholar.google.com/citations?hl=en&user=c4gKZywAAAAJ

Abstract: Intensity Diffraction Tomography (IDT) enables label-free, 3D quantitative phase imaging using simple hardware like a standard microscope with programmable LED illumination. While cost-effective and stable, conventional IDT relies on simplified models that limit its accuracy for complex, multiple-scattering samples common in biology and materials science. This dissertation focuses on developing robust computational methods to overcome these limitations and expand IDT's applicability.

Key contributions include: 1) The development and implementation of an efficient non-paraxial multiple-scattering forward model capable of accurately simulating light propagation in thick, strongly scattering samples under high-NA illumination. 2) Advanced reconstruction algorithms, incorporating both model-based optimization and deep learning strategies, to solve the challenging inverse scattering problem, yielding improved 3D refractive index maps. 3) The introduction and validation of reflection-mode IDT for imaging samples on reflective surfaces, extending the technique to industrial inspection and metrology. This involved adapting the multiple-scattering framework for reflection geometries, creating specialized reconstruction and calibration techniques, and demonstrating high-resolution volumetric imaging of complex multi-layer structures.

These advancements significantly enhance IDT's ability to quantitatively image complex samples in both transmission and reflection modes, broadening its impact across biomedical research and industrial applications while preserving its inherent simplicity and stability.