Stimulated Low-Frequency Research Articles

Stimulated Low-Frequency Scattering of Laser Radiation in an Aqueous Suspension of Viruses in the Frequency Range 1–60 GHz

Stimulated Low-Frequency Scattering of Laser Radiation in an Aqueous Suspension of Viruses in the Frequency Range 1–60 GHz

Frequency Shift for the Stimulated Low-Frequency Raman Scattering in Aqueous Suspensions of Viruses with a Change in the Laser Pump Intensity

Frequency Shift for the Stimulated Low-Frequency Raman Scattering in Aqueous Suspensions of Viruses with a Change in the Laser Pump Intensity

Dynamic Stimulated Low-Frequency Light Scattering in a Nanodispersed Liquid Medium

Dynamic Stimulated Low-Frequency Light Scattering in a Nanodispersed Liquid Medium

Stimulated Low-Frequency Raman Scattering in Brome Mosaic Virus

We experimentally register stimulated low-frequency Raman scattering (SLFRS) in the suspension of brome mosaic virus (BMV) in phosphate buffer with very high conversion efficiency. We identify two components of the SLFRS spectrum as the breathing and quadrupole modes of BMV and determine damping characteristics and gain factors for these modes. We show that, using the core–shell model for BMV and taking into account the influence of the environment, the acoustic properties of individual components of such a composite nanosystem can be determined. Thus, we define the sound velocity in the RNA core of BMV, in view of spectral characteristics of SLFRS.

Stimulated Low-Frequency Scattering of Light in an Aqueous Suspension of the Tobacco Mosaic Virus

Stimulated low-frequency scattering of light by aqueous suspensions of the tobacco mosaic virus with the scattering frequency depending on the concentration of the virus is observed for the first time. For concentrations of ∼1 × 1012 and ∼2 × 1012 cm–3, the Stokes components of scattered light are shifted by ∼43.99 and ∼31.08 GHz, respectively. At the same time, the competing process of stimulated Brillouin scattering in these heterogeneous media is suppressed. The theory of stimulated emission resulting from normal-mode vibrations of solvent-molecule-loaded cylindrical nanoparticles driven by ponderomotive forces in the field of two copropagating pump electromagnetic waves is developed for the first time. The theoretically estimated frequency shift of the Stokes component is ∼50 GHz, which agrees with the experimental result. It remains unclear why a decrease in the thickness of the liquid layer with a simultaneous increase in concentration selectively favors a decrease in the frequency of coherent normal-mode vibrations of the virus participating in stimulated low-frequency scattering.

Stimulated Low-Frequency Raman Scattering in a Single-Crystal Diamond with a Buried Graphitized Layer

The results of experimental observation of stimulated low-frequency Raman scattering (SLFRS) in a single-crystal diamond with a buried graphitized layer created as a result of nonlinear interaction of high-power nanosecond laser pulse with eigen oscillations of nanosized layers of diamond-graphite structures are presented. It is demonstrated that the frequency shift of the SLFRS is on the order of 10 GHz and is inversely proportional to geometrical dimensions of the nanolayers composing the structure.

Stimulated Low-Frequency Raman Scattering in Albumin

Stimulated low-frequency Raman scattering can give essential information about the elastic properties of different nanoparticles systems, in particular, biological nanostructures. In the present study, low-frequency vibrational modes in human and bovine serum albumin were for the first time investigated using stimulated low-frequency Raman scattering. Stimulated low-frequency Raman scattering frequency shifts, corresponding to acoustic eigenfrequencies of the sample, were registered by Fabri-Perot interferometers. Conversion efficiency, threshold and set of eigenfrequencies were also measured. Stimulated low-frequency Raman scattering can be applied for biological objects identification and impact on them.

Intracavity Stimulated Low-Frequency Raman Scattering

Intracavity stimulated low-frequency Raman scattering on elastic vibrations of submicrometer latex particles in an aqueous suspension is experimentally implemented for the first time.

Stimulated Low-Frequency Raman Scattering in LaF3 Suspensions

We observe stimulated low-frequency Raman scattering (SLFRS) caused by laser pulse interaction with acoustic vibrations of nanoparticles in water suspensions of LaF3 nanoparticles. We show that frequency shifts of the scattering correspond to the eigenfrequencies of nanoparticles vibrations. LaF3 nanoparticles were synthesized in the presence of glycine by a double jet precipitation technique at various initial concentrations of reagents. We investigate the morphologies and particle sizes as well as size distributions of the particles prepared using transmission electron microscopy (TEM) and dynamical light scattering (DLS). In view of the absorption spectroscopy, we show that the reaction system components and products have no absorption in the visible region, including λ = 694.3 nm. From the luminescence spectroscopy, we find also that they do not emit at λ = 694.3 nm excitation.

Stimulated low frequency Raman scattering in cupric oxide nanoparticles water suspension

Abstract Cupric oxide nanoparticles with average size of 213.2 nm, were synthesized in acoustoplasma discharge for investigating their vibrational properties. The low-frequency acoustic mode in cupric oxide (CuO) nanoparticles has been studied by stimulated low-frequency Raman scattering (SLFRS). SLFRS conversion efficiency, threshold and frequency shift of the scattered light are measured.

Stimulated low-frequency emission from anisotropic molecules in microdroplets

Abstract Spectral broadening of the input-laser line and the stimulated Raman line have been observed in microdroplets of carbon disulfide, benzyl alcohol, toluene, chloroform and a binary mixture of carbon disulfide in ethanol. The broadening is asymmetrical and extends more than 500 cm −1 towards the low-frequency side of the input-laser line and the stimulated Raman lines. The broadening is proposed to arise from multiple-order stimulated low-frequency scattering associated with librational and dipole—induced-dipole translational motions.