  This review discusses the ultrafast magnetization dynamics within the
gigahertz to terahertz frequency range in ferrimagnetic rare-earth iron garnets
with different substitutions. In these garnets, the roles of spin-orbit and
exchange interactions have been detected using femtosecond laser pulses via the
inverse Faraday effect. The all-optical control of spin-wave and Kaplan-Kittel
exchange resonance modes in different frequency ranges is shown. Generation and
localization of the electric field distribution inside the garnet through the
metal-bound surface plasmon-polariton strongly enhance the amplitude of the
exchange resonance modes. The exchange resonance mode in yttrium iron garnets
was observed using circularly polarized Raman spectroscopy. The results of this
study may be utilized in the development of a wide class of optomagnonic
devices in the gigahertz to terahertz frequency range.
