Nikolay V. Tcherniega

Photon distribution function, tomograms and entanglement in stimulated Raman scattering

Several aspects of the stimulated Raman scattering process are studied using the model of a two-dimensional oscillator. The photons of the Stokes mode are taken as one mode of the oscillator and the phonons of the medium are taken as the other mode of the oscillator. The interaction Hamiltonian of the photons and phonons is taken to be quadratic in the annihilation and creation operators of photons and phonons. The laser is considered as a classical light source and its depletion is neglected. The photon?phonon joint probability distribution function is found and expressed in terms of Hermite polynomials of four variables. The general formula for the photon number probability distribution as a function of the laser-field intensity and the medium parameters is obtained in terms of Hermite polynomials of two variables. It is shown that the phenomenon of entanglement appears in photon?phonon modes due to the interaction of the light with the medium. The tomograms of the photon?phonon states and (averaged over the phonon mode) photon states are investigated within the framework of a symplectic tomography scheme.

Stimulated globular scattering and photonic flame effect : new nonlinear optics phenomena

Novel nonlinear optical phenomena - photonic flame effect (PFE) and stimulated globular scattering (SGS) are discussed.PFE consisted in the appearance of the few seconds duration emission in blue-green spectral range under 20 ns ruby laser pulse excitation and simultaneous excitation of several spatially separated synthetic opal crystalls situated on the Cu plate. SGS was observed both in forward and backward directions. Spectral and energetical SGS characteristics were measured.Novel nonlinear optical effects - photonic flame effect (PFE)1,2 and stimulated globular scattering (SGS)3 - have been discovered. SGS was observed both in forward and backward direction. Pure opal crystal, consisting of the close-packed SiO2 globules with diameter 200 nm, and crystal with pores, filled with molecular liquid, have been studied. Two Stokes components, shifted from the exciting light frequency by 0.4 - 0.6 cm-1, have been observed in SGS. Photonic flame effect consisted in the appearance of the few seconds duration emission in blue-green spectral range under 20 ns ruby laser pulse excitation.

Stimulated light scatterings in submicron single crystal diamond films implanted with light ions

Stimulated low frequency Raman scattering (SLFRS) in submicron single-crystal diamond films (SCD) with a graphitized layer built-in is investigated. The value of SLFRS frequency shift lies in gigahertz range (8.4-9.3 GHz) and shows the morphological dependence (inverse dependence on the thicknesses of SCD layers). Experimentally estimated SLFRS conversion efficiency and threshold evidence about the coherent phonon mode excitation in submicron SCDs as a result of nonlinear interaction of high-power laser wave with an eigen vibration of nanosized graphitized layer built-in.

Stimulated low-frequency Raman scattering in aqueous suspension of nanoparticles

The low-frequency acoustic mode in nanoparticles of different nature in aqueous suspension has been studied by stimulated low-frequency Raman scattering (SLFRS). Nanoparticles investigated (CuO, Ag, Au, ZnS) had different dimensions and different vibrational properties. Synthesis of cupric oxide nanoparticles in acoustoplasma discharge is described in details. SLFRS has been excited by nanosecond pulses of ruby laser. Spectra of the scattered light had been registered with the help of Fabry-Perot interferometer. SLFRS conversion efficiency, threshold and frequency shift of the scattered light are measured.

Anti-Stokes luminescence in nanoscale systems

Luminescence of nanomaterials in green-blue range, anti-Stokes with respect to the exciting ruby laser pulses, is studied at different temperatures. Both high-ordered systems and random materials have been used as samples. Spectral and temporal characteristics of the luminescence have been measured. Two types of temporal behavior have been found out depend on temperature. Long luminescence (up to few seconds) under nanosecond excitation has been shown to exist only at the temperatures below the definite threshold, which was found to be 110 K.

Stimulated globular scattering in photonic crystals

Novel nonlinear optical effect - stimulated globular scattering (SOS) - was discovered. SGS was observed both in forward and backward direction. Pure opal crystal consisting of the close-packed Si02 globes with diameter 200 nm, and crystal with pores filled with molecular liquid have been studied. Two Stokes components, shifted from the exciting light frequency by 0.4 - 0.6 cm-1 have been observed.