In this laboratory, we have our highest energy femtosecond pulses of 5 mJ with a 1 kHz repetition rate from a Ti:Sapphire regenerative amplifier system. We utilize these powerful laser pulses to study nonlinear processes and to do pump-probe spectroscopy in different domains of the electromagnetic spectrum. By supercontinuum generation, we cover the visible to NIR spectrum ranging from 240 nm to 20 µm; by photoconductive antenna/waveguides, we generate THz radiation covering the millimeter region. With different experimental setups, including two-color pump-probe, transient absorption spectroscopy, and time-resolved optical pump terahertz probe time-domain spectroscopy, we studied charge and carrier dynamics in organic photovoltaic and 2D van der Waals materials [1-4]. Besides fundamental research, we also engage in the development of new technologies, for example, we work on development of THz radiation sources [5,6], and in biomedicine applications including wide-field temporal focused two-photon microscopy [7] and photo-stimulated drug delivery system [8].
