In this talk I will present our recent experimental investigations on
carrier dynamics in graphene studied via pump-probe spectroscopy, on
time-resolved photoluminescence dynamics of single InAs/GaAs quantum
dots under pulsed inter-sublevel excitation, and on sub-diffraction
limited terahertz imaging by a GaAs-based superlens studied by
scattering near-field optical microscopy. The experiments have been
carried out using the mid-infrared/terahertz free-electron laser
facility FELBE in Dresden, Germany.