My research interest focuses on nonlinear optical microscopy and spectroscopy with applications in biophysics. One area is developing advanced optical microscopy for molecular and cellular imaging in medical research. Nonlinear optical microscopes based upon two-photon fluorescence, coherent anti-Stokes Raman scattering and pump-probe method, are developed to image a variety of biological tissues and cells both in vitro and in vivo. I am also developing femtosecond laser spectroscopy to study ultrafast dynamics in molecular systems, e.g. organic photovoltaics and novel two-dimensional materials.