Done research work (both theoretical and experimental) on fundamental quantum optics, quantum statistics, light-matter interactions, atomic coherence in multi-level systems, semiconductor lasers, applications of quantum states of light, applications of optical spectroscopy, microstructures in single optical crystals, optical properties of solid materials, optical properties of single quantum dots/rods, and so on. Total external funding of more than $6,500,000 in the past ten years. Published more than 170 refereed journal papers in high quality physics journals, such as Physical Review Letters, Physical Review A, Physical Review B, Applied Physics Letters, Optics Letters, NanoLetters, Physics Letters, and so on. More than 120 presentations in international and national conferences and workshops including invited talks. One US patent was granted on October 13, 1998 (US patent #5,821,546, Xiao, et al, “Method and System for Fecal Detection”)