We would like to mark the sad passing of Professor Gabriel Popescu, our dear friend and a former colleague in the Spectroscopy Laboratory at MIT. Gabi was the William L. Everitt Distinguished Professor in Electrical and Computer Engineering Department of the University of Illinois at Urbana-Champaign and the founder of Phi Optics. Prior to establishing his laboratory in Illinois, Gabi worked with late Professors Michael Feld and Ramachandra Dasari in the SpecLab from 2002-2007 where he was a core member of Spectratone (SpectLab Chorus).
Professor Popescu was one of the pioneers who played a leading role in popularizing quantitative phase imaging today. His early invention of Diffraction Phase Microscopy (DPM), as a simple but robust phase imaging method, is one of the milestones in the field that inspired numerous instrumentations and applications. Professor Popescu contributed to the development of many generations of phase microscopes improving their resolution, sensitivity, depth selectivity, and robustness. Beyond extending the frontiers in instrumentation, Professor Popescu had also been influential in identifying important applications of quantitative phase microscopy ranging from studying neuronal communications to very recent analyzing cell growth and viability by introducing computational specificity. One of his most important contributions is in demonstrating quantitative phase imaging for quantifying cell mass changes with femtogram sensitivity in vivo, which is important for understanding how cells regulate their growth cycles.
Today, Professor Popescu is widely recognized as one of the leaders in the field of quantitative phase imaging and Biophotonics overall. He was a co-founding chair of Quantitative Phase Imaging Conference at SPIE Photonic West Conference. He was also Fellow of Optica, SPIE and AIBME. His passion and impact in science is reflected by his prolific publications and around 300 invited lectures and talks he delivered all over the world. One should further recognize his contributions to pedagogy as exemplified by the textbooks he wrote, including the recent Principles of Biophotonics in progress. We are greatly saddened by his sudden death, but we are confident that his excellent body of work will be carried forward by his students and postdocs as well as many colleagues in the field.