Influence of aperture effects on the spectral structure of stimulated Raman scattering by optical phonons and polaritons in a resonator

The spectral structure of stimulated Raman scattering (STRS) by optical phonons and polaritons of the A(z) symmetry in a crystal of LiIO₃ in a resonator was investigated experimentally as a function of the intensity of pump radiation traveling at an angle to the STRS resonator. The STRS spectra were fully identified. The special characteristics of these spectra were attributed to an aperture effect which, in particular, reduced the gain of the polariton scattering because of the emission of a polariton wave from a pump beam even when the angle between this beam and the STRS resonator axis was small.