About me

Hello! I am a graduate student at UC Berkeley, working with Prof. Laura Waller. I started my graduate studies in 2022 after graduating with a B.S. in Electrical Engineering from Peking University, China.

My research focuses on developing and applying advanced computational imaging techniques, with expertise in signal processing, optimization algorithms, and their applications in image reconstruction and aberration characterization. Previously, I worked on non-line-of-sight imaging with Prof. Andreas Velten. I play with signal processing in the Fourier domain a lot, and I always love combining physical hardware and computational methods to create something new.

Projects

Enhanced EUV Mask Imaging using Fourier Ptychographic Microscopy

Chaoying Gu, Antoine Islegen-Wojdyla, Markus Benk, Kenneth A. Goldberg, Laura Waller

IEEE CISA 2024  ·  SPIE Advanced Lithography 2025

CISA paper SPIE paper code

• Extensively evaluated reconstruction quality of existing algorithms under EUV microscope aberration and achieved a 36-fold increase in the usable field-of-view from the nominal 5×5 μm² diffraction-limited area.
• Developed an automatic differentiation framework for system self-calibration and wavefront error correction, enabling robust reconstruction of elliptical pupils and attenuated phase shift masks.
• Validated Fourier FPM as a promising technique for advanced EUV mask imaging, achieving quantitative phase recovery and through-focus simulation using experimental data from the SHARP EUV microscope at Lawrence Berkeley National Laboratory.

Large-scale Compressive Microscopy via Diffractive Multiplexing across a Sensor Array

Kevin C. Zhou, Chaoying Gu, Muneki Ikeda, Tina M. Hayward, Nicholas Antipa, Rajesh Menon, Roarke Horstmeyer, Saul Kato, Laura Waller

Photonics West 2024

arXiv abstract

• Developed a computational microscope using a sensor array and a diffractive optical element (DOE) to achieve high-throughput imaging, covering a 5 cm × 6.6 cm region with ~0.6 gigapixels.
• Developed the patch-based memory-efficient reconstruction algorithm involving deconvolution of diffraction patterns to fill in sensor gaps.

Fast Non-line-of-sight Imaging with Non-planar Relay Surfaces

Chaoying Gu, Talha Sultan, Khadijeh Masumnia-Bisheh, Laura Waller, and Andreas Velten

ICCP 2023

paper code

• Proposed a novel computational method that effectively performs 3D diffraction propagation for arbitrary non-planar surfaces.
• Achieved orders of magnitude better complexity compared to state-of-the-art algorithms without quality degradation, validated on experimental data.