Raman scattering by polaritons in Ti:LiNbO3 waveguides

A general theory of Raman scattering in piezoelectric slab waveguides is presented. If the anisotropy of the uniaxial waveguide material is sufficiently large, incident slab‐guided waves can be scattered by polaritons of the upper branch of the polariton dispersion curve. The angular dependence ω2(θ) of the scattered‐wave frequency has been calculated in detail, for both y‐ and z‐cut Ti:LiNbO3 waveguides in the polariton frequency range ωp=900–5160 cm−1 (pump wavelength 4880 Å). The detection of weak proton vibrations within the strong polariton Raman spectrum of proton‐exchanged Ti:LiNbO3 waveguides is discussed.