  Current pulses of up to 20 A and as short as 3 ps are generated by a low
temperature grown GaAs (lt-GaAs) photoconductive switch and guided through a
coplanar waveguide, resulting in a 0.6 Tesla terahertz (THz) magnetic field
pulse. The pulse length is directly calibrated using photocurrent
autocorrelation. Magnetic excitations in Fe microstructures are studied by
time-resolved Kerr spectroscopy and compared with micromagnetic simulations. A
response within less than 10 ps to the THz electromagnetic field pulse is
found.
