Quantum optics, atomic physics, quantum information science.

1977~1978 Univ. of Rochester Researcher
1979~1980 Univ. of Arizona Researcher
1980~1981 Univ. of New Mexico Researcher
1981~1989 Oakland Univ. assistant professor, associate professor
1987~1988 KAIST Visiting Professor
1989~2012 KAIST Professor
2012~ KAIST Emeritus Professor, UNIST hair professor
1997~1999 The Korean Physical Society Physics Division Chairman
2001~2002 The Korean Physical Society JKPS Editor-in-Chief Executive Director
2001~2003 KAIST Dean of Academic Affairs

2006 3.1 Cultural Award, Academic Award (Natural Science Division)