Min Gu has pioneered the three-dimensional (3D) optical imaging theory for the fundamental understanding of modern 3D multiphoton optical microscopy. As such, he has led high-impact research in 3D nanophotonics and biophotonics. In particular, his breakthrough development of 3D photonic crystals reveals the new physical phenomena that underpin all-optical information technology. He has driven a new paradigm-shift in 3D optical data storage. His concept of femtosecond laser tweezing provides an entirely new way for understanding 3D dynamics of microcavity. His creative innovation of multiphoton optical endoscopy has firmly established a foundation for in vivo study of cancer origins.