Randy Bartels
University of Wisconsin-Madison
Randy A. Bartels is an investigator of the Morgridge Institute for Research and a Professor of Biomedical Engineering at the University of Wisconsin – Madison. Prof. Bartels has been awarded the Adolph Lomb Medal from the Optical Society of America, a National Science Foundation CAREER award, a Sloan Research Fellowship in physics, an Office of Naval Research Young Investigator Award, a Beckman Young Investigator Award, and a Presidential Early Career Award for Science and Engineering (PECASE). His research involves the development of novel spectroscopy and microscopy techniques applications and the development of ultrafast fiber lasers for use in these applications. He is a Fellow of the Optical Society of America and of the American Physical Society (APS). He serves on the Editorial Board of Applied Physics Letters, Photonics, an Associate Editor for Science Advances.
Presentation Title:
Computational Imaging from Structured Light to Photon Statistics
Abstract:
Computational imaging expands what we can measure by jointly designing illumination, detection, and reconstruction. This talk explores that idea across fluorescence, quantitative phase, and photon antibunching imaging, connecting spatial information encoded by structured illumination with information carried by the statistics of photon emission.
I will begin with spatial frequency modulation imaging (SPIFI) and coherent holographic image reconstruction by phase transfer (CHIRPT). These approaches encode spatial information in time-varying signals recorded by single-element detectors, allowing images to be reconstructed from measurements without spatially resolved detection. I will discuss fluorescence imaging with these methods, including how CHIRPT transfers illumination phase information into fluorescence signals to enable holographic reconstruction. I will then turn to quantitative phase imaging, where computational reconstruction reveals optical path-length variations and provides label-free measurements of specimen structure.
Finally, I will examine photon antibunching as a source of imaging information beyond average intensity. Correlations arising from the suppressed probability of closely spaced emissions from individual quantum emitters can be combined with structured illumination to recover finer spatial detail. This progression, from illumination encoding to phase inference to photon statistics, highlights how physical models and measurement design shape the information available for reconstruction. Throughout, the emphasis will be on the opportunities and tradeoffs that emerge when optics, detection, and computation are designed together.
- Fields
- Chem-Img-25, Speaker, and SYM-FALL-2026