Excitation of C-60 using a chirped free electron laser

Gas phase C-60 is resonantly excited using picosecond infrared (IR) pulses from a free electron laser. The excitation can be very high, reaching levels where the thermal emission of electrons from C-60 is observed. The excitation is much more efficient when the IR radiation is chirped to lower frequencies during the excitation process. The excitation process is modeled and the results are compared to the experiment. (C) 1998 Optical Society of America.