Stanford EE

Photoacoustic, Light-Speed, and Quantum Imaging

Prof. Lihong Wang (California Institute of Technology)

ABSTRACT: We developed photoacoustic tomography (PAT) to peer deep into biological tissue. PAT provides in vivo functional, metabolic, molecular, and histologic imaging across the scales of organelles through organisms. We also developed light-speed compressed ultrafast photography (CUP) to record 219 trillion frames per second, orders of magnitude faster than commercially available camera technologies. CUP can record in real time the fastest phenomenon in nature, namely, light propagation for the first time and can be slowed down for slower phenomena such as neural conduction. We are exploring quantum entanglement for imaging. PAT physically combines optical and ultrasonic waves. Conventional high-resolution optical imaging of scattering tissue is restricted to depths within the optical diffusion limit (~1mm). PAT beats this limit and provides centimeter-scale deep penetration at high ultrasonic resolution and high optical contrast by sensing molecules. Broad applications include early-cancer detection and brain imaging. The annual conference on PAT has become the largest in SPIE’s 20,000-attendee Photonics West since 2010. CUP with a single exposure can image transient events occurring on a time scale down to 10s of femtoseconds. Akin to traditional photography, CUP is receive-only—avoiding specialized active illumination required by other single-shot ultrafast imagers. CUP can be coupled with front optics ranging from microscopes to telescopes for widespread applications in both fundamental and applied sciences, ranging from biology to cosmophysics. Quantum imaging at the Heisenberg limit improves spatial resolution linearly with the number of quanta, faster than the square-root standard quantum limit.

Biography: Lihong Wang edited the first book on photoacoustic tomography. His book entitled “Biomedical Optics: Principles and Imaging,” one of the first textbooks in the field, won the 2010 Joseph W. Goodman Book Writing Award. He has published 590 peer-reviewed journal articles and delivered 600 keynote/plenary/invited talks. His Google Scholar h-index and citations have reached 154 and 104K. His laboratory was the first to report functional photoacoustic tomography, 3D photoacoustic microscopy, photoacoustic endoscopy, photoacoustic reporter gene imaging, the universal photoacoustic reconstruction algorithm, and CUP (world’s fastest camera). He chairs the annual conference on Photons plus Ultrasound, the largest conference at Photonics West. He was the Editor-in-Chief of the Journal of Biomedical Optics. He received the NIH Director’s Pioneer, NIH Director’s Transformative Research, and NIH/NCI Outstanding Investigator awards. He also received the OSA C.E.K. Mees Medal, IEEE Technical Achievement Award, IEEE Biomedical Engineering Award, SPIE Britton Chance Biomedical Optics Award, IPPA Senior Prize, and OSA Michael S. Feld Biophotonics Award. He is a Fellow of the AAAS, AIMBE, Electromagnetics Academy, IAMBE, IEEE, NAI, OSA, and SPIE as well as a Foreign Fellow of COS. An honorary doctorate was conferred on him by Lund University, Sweden. He was inducted into the National Academy of Engineering.

This seminar is sponsored by the Department of Applied Physics and the Ginzton Laboratory