Nonlinear optical spectroscopy of epitaxial magnetic garnet films
V. V. Pavlov and R. V. Pisarev
A. F. Ioffe Physical Technical Institute of the Russian Academy of Sciences, St. Petersburg, 194021 Russia
M. Fiebig and D. Fröhlich
Institut für Physik, Universität Dortmund, 44221 Dortmund, Germany
Received February 1, 2002
Second and third harmonic optical spectra are studied in epitaxial magnetic thin films in the spectral ranges 1.7-3.2 eV and 2.4-4.2 eV, respectively. No significant increase of the intensity of the nonlinear spectra is found above the bandgap near 3.2 eV, where the linear absorption increases by two orders of magnitude. Large magnetic contributions to the second harmonic spectra and magnetic contrast as high as 100% are observed at selected photon energies.
Contrary to that, no magnetic contribution to the third harmonic spectra is found.PACS: 78.20.-e - Optical properties of bulk materials and thin films (for optical properties related to materials treatment, see 81.40.Tv; for optical materials, see 42.70-a; for optical properties of superconductors, see 74.25.Gs; for optical properties of rocks and mine 42.65.Ky - Frequency conversion; harmonic generation, including higher-order harmonic generation (see also 42.79.Nv Optical frequency converters) 75.50.Gg - Ferrimagnetics