In multiple scattering media at high excitation intensities, compulsory light scattering (SRS) of organic laser dyes arises simultaneously with their chaotic generation. Together, they create a coupled effect of SRS-RL, in which RL radiation plays a stimulating role for SRS. This radiation stimulates the forced oscillation of the dye molecules at frequencies whose Stokes lines fall within the range of the RL spectrum. As a result, on all these lines there is a SRS. The radiation spectrum of dyes becomes quasilinear, in which, on the background of a continuous component due to RL, there are Stokes lines of SRS corresponding to the segment of the spectrum of Stokes lines of combinational scattering within the range of the RL spectrum. At present, only the influence of RL on the onset of SRS has been investigated, and the reverse effect has not been studied in practice. At the same time, for the understanding of the regularities of the WRC-RL process, the effect is very important, since it can be used practically in Raman scattering spectroscopy. Therefore, the purpose of this work is to study this effect. To this end, the radiation of dyes injected into the vesicular polymer film alone and in the mixture was investigated.
The paper presents a procedure for measuring laser radiation reflection and scattering coefficients of polished surface. A relation
between the scattered light intensity and the polished surface roughness is studied. It is demonstrated that colorimetric
characteristics of non-metallic materials can be determined from the light scattering and reflection coefficients. This
work has demonstrated a possibility of and created prerequisites for the development of an express method for tentative
assessment of polished surface roughness. Of interest is the use of the β(Rz) function for the purposes of quality inspection
of polished surfaces of natural and synthetic stone and other non-metallic materials. It was established that the most
relevant parameter of roughness, which can be defined by the light reflection is Rz. The Dependency of the reflection
factor from parameter of roughness Rz was approximated by formula with inaccuracy 5-10%. Inaccuracy of the determination
of roughness Rz has formed 1%. It was shown that method of the surface roughness control using the light reflection
factor is the most efficient for surfaces with roughness Rz <0.3 microns, typical for finish diamond-abrasive machining.
The random lasing of R6G-dyed vesicular polymeric films was investigated. The short-range ordering of vesicles allows
classifying the films as 2D short-range photonic crystals. Nevertheless the ordering causes neither resonant nor
interference conditions in this medium but the films reveal good lasing parameters: low lasing threshold and high
luminescence-to-lasing transition rate. The obtained lasing spectra reveal quasi-linear structure when pump intensity is
considerably above the lasing threshold and the dye concentration is over2*10-3M/l. All spectral lines are good
reproducible from shot to shot. The dye concentration as well as pump intensity do not influence the frequencies of
spectral lines. In the absence of any resonant conditions, we discuss the latent vibronic structure of the fluorescence
spectrum and Raman scattering revealing as the most probable reasons for the random lasing spectrum structure. The
Raman and vibronic frequencies are compared with the observed lasing spectrum lines. Good correlation between the
lasing and Raman frequencies is shown. The mechanism of the quasi-linear lasing spectrum formation by amplification
of the combined radiation of resonant Raman scattering and luminescence up to saturation is proposed. The random
lasing spectrum in diffusive regime is denoted to provide a new way of laser dye Raman scattering investigation.
Monte-Carlo simulation of random lasing under diffusive regime of light propagation in active random medium was
carried out. Computing has been carried out for active media being suspension of dielectric particles in rhodamine 6G
solution. Dependence of emitted photons density distribution in active media, their total quantity and spectrum on active
medium length in a pump beam direction. Spatial distributions of pump radiation and amplification in a sample have
been taken into account. It has been shown that quantity of emitted photons non-steadily depends on sample length and
the maximal density of emitted photons is located at a depth near front (pump) sample side. Optimal active medium
length is exists and maximizes total number of emitted photons and narrows spectrum of emission. Computing results
are conformed to experiments.
The absorption, fluorescence and phosphorescence of the carbazole-containg polymers with phosphore groups in the main chain of two types and without spacer were studied. It was shown that spectral properties of pf2-sep polymer are connected mainly with optical transitions in individual carbazole chromophores. The optical properties of pf2-conj polymer are rather different comparative to the pf2-sep. That is caused by perturbation carbazole groups electron system by phosphor-groups and influence carbazole groups each other. This perturbation takes place under special relative geometrical displacement of carbazole and phosphor groups.