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Two‐Photon Absorption of CaF 2 :Eu 2+
Author(s) -
Bayer E.,
Schaack G.
Publication year - 1970
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.19700410239
Subject(s) - anisotropy , photon , absorption (acoustics) , polarization (electrochemistry) , two photon absorption , electron , atomic physics , absorption band , spectroscopy , absorption spectroscopy , symmetry (geometry) , molecular physics , chemistry , materials science , optics , physics , laser , quantum mechanics , geometry , mathematics
Abstract The technique of two‐photon‐absorption spectroscopy with polarized laser‐light is applied to localized excitations of 4f‐electrons in crystals. The relevant selection rules are discussed. A method is outlined for the unique determination of the relative magnitude of partial transition‐probabilities with different types of symmetry using linear and circular polarization of the incident light. The anisotropy of the two‐photon absorption has been measured in single crystals of cubic CaF 2 :Eu 2+ at five different wavenumbers. The relative intensities of transitions belonging to the three different types of symmetry active in two‐photon absorption are constant in the range of the e‐band (26,000 to 29,000 cm −1 ) but differ from these values at 37,700 cm −1 in the range between the e‐ and the t‐band. This result is discussed in the frame of existing interpretations of the 4f 6 5d‐configuration of Eu 2+ in CaF 2 .