Ultrafast IR and THz spectroscopy of photo-induced insulator to metal transition in highly correlated organic system

► Mid-infrared and THz pump-probe spectroscopy were performed in organic conductors. ► Dynamics of photo-induced insulator to metal transition (PIMT) were observed. ► In charge ordered insulators, PIMTs were driven by the electronic process. ► In dimer Mott insulator, PIMT was driven by the lattice displacement.