Symmetry and light coupling to phononic and collective magnetic excitations in SrCu2"BO3…2

resonance behavior of these magnetic modes and we show that one of these can be ascribed to an effective intradimer Dzyaloshinskii-Moriya spin interaction. Our data also suggest a possible explanation for the existence of a strongly bound two-triplet state in the singlet sector which has an energy below the spin gap. The low temperature phononic spectra suggest strong spin-phonon coupling and show intriguing quasidegeneracy of modes in the context of the present crystal structure determination.