Sep 20 (Thu) @ 12:00pm: "A CMOS SPAD Image Sensor for Fluorescence Lifetime Imaging with In-Pixel Mean-Delay Estimation.," Wonsik Oh, ECE PhD Defense

Location: Engineering Science Bldg (ESB), Room 2003
Oh's Zoom Defense Presentation

Abstract

Fluorescence lifetime imaging microscopy (FLIM) provides quantitative contrast based on fluorescence decay dynamics and is widely used for biological and chemical sensing. However, conventional FLIM systems often rely on precise time-resolved photon measurements, resulting in complex timing circuitry, large data volume, and high readout bandwidth. This work presents a CMOS single-photon avalanche diode (SPAD) image sensor that enables in-pixel fluorescence lifetime estimation through analog mean-delay estimation. By exploiting the statistical relationship between fluorescence lifetime and the mean photon arrival time, the proposed architecture accumulates photon arrival delays directly within each pixel in the analog domain. This in-pixel processing enables fluorescence lifetime to be estimated from the accumulated delay and photon count, eliminating the need for fine-resolution timing circuits, photon-arrival histograms, and explicit deconvolution.

Bio

Wonsik Oh is a Ph.D. candidate in Electrical and Computer Engineering at the University of California, Santa Barbara (UCSB), advised by Professor Luke Theogarajan. He specializes in analog and mixed-signal circuit design. He received his B.S. degree in Semiconductor System Engineering from Sungkyunkwan University, South Korea, and his M.S. degree in Electrical and Computer Engineering from UCSB in 2024.

Hosted By: ECE Professor Luke Theogarajan

Submitted By: Wonsik Oh – Oh's Email