Transmission measurements of a barium ferrite pressed-powder sample ha
ve been made with an optically switched picosecond-pulse spectrometer.
By comparison to millimeter-wave spectroscopy of the same sample, fea
tures related to the ferrimagnetic resonance have been identified in t
he pulse spectrum. Time-domain spectra predicted from models of the pe
rmeability indicate significant discrepancies with the experimental sh
ort-pulse line shape.