During his stay at AT&T Bell Laboratories, he pioneered and demonstrated the first proton-implanted VCSELs in 1990 and holds the original patent on this industrial VCSEL. In 1991 he joined the Department of Physics of KAIST where he continued his research on VCSELs and started new research on photonic crystal nano-lasers. His laboratory demonstrated various forms of photonic crystal laser including the first electrically-driven photonic crystal laser. His recent interest lies in on the physics of light-matter interaction at the nano-scale and the ultimate light source for photonic integrated circuits and quantum information science. From 2003 to 2004 he was an IEEE LEOS Distinguish Lecturer. Prof. Lee served as an Associate Editor of Optics Express. He is a Fellow of IEEE and the Optical Society of America. Domestically he received numerous awards including the National Academy of Science Award, Korea Scientist Award and the most recent Korea Best Scientist and Engineer Award. In 2014 He received the Humboldt Research Award and the IEEE Photonics Society Engineering Achievement Award. He co-authored more than 180 international journal papers and patents related to nanophotonics. He advised and produced over 40 PhD's in physics during his stay at KAIST.