Abstract

Frequency-angular spectra of light elastic scattering and inelastic small-angle Raman scattering in inhomogeneous crystals with different types of layer superstructure were investigated. In order to analyse effects, caused by inhomogeneity, singly and multiply domained ferroelectrie crystals of barium sodium niobate (NBS), yttrium-doped lithium niobate (LN), and KH₂PO₄ (KDP) were studied. Due to the crystal growth conditions the layer-type domains formed a periodic two-dimensional superlattice in NBS and NL. In the case of KDP the domain subsystem consisted of domain blocks with quasiperiodic structure. The frequency-angular intensity distribution of polarized scattered light was registered at small angles (0-10°) relatively to the pump direction. This technique allows to study polariton dispersion in Raman spectra.¹ pump radiation being of laser type. Elastic scattering spectra were obtained with a source of polarised radiation of wide spectral range.

© 1994 IEEE