RAMAN SCATTERING OF POLARITONS IN A KT_iOPO₄ CRYSTAL

The spontaneous Raman scattering of polaritons in the biazial orthorhombic KT_iOPO₄(KTP) crystal was investigated with a cw Ar⁺ laser. The dispersion branches of polaritons associated with A₁-phonons have been calculated from spectral data for different wave vector directions from near-forward scattering experiments. The angular dependence of Raman scattering efficiency (RSE) in 60-300cm^-1 and 500-800cm^-1 regions are shown schematically. The collective interaction of multi-mode lattice vibrations and an “overall” effect are discussed phenomenally.