抄録
Femtosecond laser processing of magnetic materials is described. A spatially selective change of
magnetism from paramagnetic to ferrimagnetic behaviors was successfully induced in spinel ZnFe2O4
thin films prepared by a sputtering method. The cation distribution in the irradiated region became
disordered due to local heating, and the metastable phase was frozen by rapid quenching after irradiation,
forming the ferrimagnetic phase. Nanoparticle composites, composed of ferrimagnetic magnetite and
plasmonic Al, were induced by femtosecond laser irradiation inside transparent glasses. The Faraday
response due to the magnetic phase was enhanced by the localized surface plasmon resonance of metallic
Al nanoparticles. Optical waveguides were fabricated inside the transparent silica xerogels containing
Fe3O4 nanoparticles using a fs-laser irradiation process. We evaluated the magneto-optical Faraday
effect for propagated light through the waveguides.
