Dye-induced spectral narrowing of stimulated scattering in CS2

Narrowing of the super-broadened wings of both stimulated Rayleigh and Raman scattering spectral profiles in carbon disulfide (CS2) has been observed in a liquid–core fiber system doped with 10 ppm of a dye (Coumarin 337). This effect is attributed to the light-induced pre-alignment of the anisotropic molecules of CS2, caused by the reorientation mechanism of excited dye molecules along the optical pump field. In addition, the enhancement of light-induced anisotropy in the presence of an absorbing dye has been observed in a light-induced birefringence experiment and is also explained in terms of the change in the guest–host interaction induced by optical excitation.