Magnetooptical coefficients of Ho3+ions induced by electric and magnetic dipole transitions in single crystal HoIG

Measurements of the Faraday rotation of HoIG have been performed in the range 4,2-300 K in a magnetic field applied along the |111| easy direction at 1,15 micron wavelength. When , the Faraday rotation of the garnet is negative ; absolute value increases with the applied field . When , a non-linear evolution with the applied field is observed. The total Faraday rotation produced by the two Fe³⁺sublattices is considered to be the same as in YIG, the electric dipole transition contribution of the Ho³⁺sublattice is calculated. The magnetooptical coefficient Ceis strongly temperature and field dependent. The temperature evolution of Ceis linear. These results are contradictory with the assumption of temperature independent electric dipole M.O. coefficients.