Stimulated Low-frequency Raman Scattering Research Articles

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

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.

High efficiency stimulated low-frequency Raman scattering in a water suspension of dielectric submicron particles

Stimulated low-frequency Raman scattering (SLFRS) with a maximum efficiency conversion of up to 50% was registered in a water suspension of silica nanoparticles. The dispersion relations of the SiO2 spheres’ acoustic modes in the surrounding water and the damping parameters were estimated. The experimentally obtained SLFRS frequency shift corresponding to the nanoparticles’ acoustic eigenfrequency relates to the breathing mode (n = 1, l = 0).

Stimulated low-frequency Raman scattering in biological nanoparticles suspensions

The interaction of electromagnetic radiation with nanoscale particles systems (including suspension of metallic dielectric and semiconductor nanoparticles, biological nanostructures, etc.) can lead to various non-linear effects, in particular, to the stimulated low-frequency Raman scattering (SLFRS). It can provide important information about investigated system elastic properties. In the present study low-frequency vibrational modes in different biological nanoparticles systems were investigated, such as tobacco mosaic viruses (TMV), two types of potato viruses (PVX and PVA), cauliflower mosaic virus (CaMV), human and bovine serum albumin (HSA and BSA) in Tris-HCl pH7.5 buffer and in water. 20 ns ruby laser pulses were used for excitation. SLFRS frequency shifts, corresponding to acoustic eigenfrequencies of the samples were registered by Fabri-Perot interferometers. Conversion efficiency and threshold were also measured for the first time. SLFRS can be applied for nanoobjects identification and effective impact on biological nanoparticles systems.

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.

Вынужденное низкочастотное комбинационное рассеяние света в монокристаллическом алмазе с заглубленным графитизированным слоем

AbstractThe 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.

Coherent Excitation of Gigahertz Range Vibrations in Single Crystal Diamond with a Built-In Graphitized Layer

The paper presents the results of experimental observations of stimulated low-frequency Raman scattering (SLFRS) on acoustic eigenvibration of graphitized layers of different thicknesses in single-crystal diamond volume excited by a nanosecond laser pulse.

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.

Laser excitation of gigahertz vibrations in Cauliflower mosaic viruses’ suspension

The interaction of laser pulses with the Cauliflower mosaic virus (CaMV) in a Tris-HCl pH7.5 buffer is investigated. 20 ns ruby laser pulses are used for the excitation. Spectra of the light passing through the sample and reflected from it are registered with the help of a Fabri–Perot interferometer. Stimulated low-frequency Raman scattering (SLFRS) in a CaMV suspension is registered. The SLFRS frequency shift, conversion efficiency and threshold are measured for the first time, to the best of our knowledge.

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.

Coherent Phonon-Mode Excitation in Submicron Single-Crystal Diamond Films with a Graphitized Layer Built-In

We report the first experimental observation of high-efficient phonon-mode coherent excitation using stimulated low-frequency Raman scattering (SLFRS) in submicron diamond{graphite{diamond heterostructure films with an ion-beam-induced graphitized layer. We show that the SLFRS process in submicron diamond heterostructures has a frequency shift in the gigahertz range and estimate experimentally the SLFRS conversion efficiency and threshold.

Stimulated low-frequency Raman scattering in plant virus suspensions

The study deals with laser pulse interaction with plant viruses: we investigated tobacco mosaic virus (TMV) and two types of potato viruses (PVX and PVA) in Tris-HCl pH7.5 buffer and in water. We used 20 ns ruby laser pulses for excitation. We employed Fabry–Pérot interferometers to record spectra of the light passing through the sample and reflected from it. For TMV and PVX in Tris-HCl pH7.5 buffer, same as for PVA in water, we observed additional spectral lines corresponding to the stimulated low-frequency Raman scattering (SLFRS). We believe we were the first to measure SLFRS frequency shifts, conversion efficiency and threshold. High conversion efficiency of the scattered light is evidence of laser pulses efficiently exciting gigahertz vibrations in viruses. SLFRS can be used to identify and affect biological nanoparticles.

Stimulated low frequency Raman scattering in cupric oxide nanoparticles water suspension

Cupric oxide nanoparticles with average size of 213.2nm, 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 Raman scattering in a suspension of tobacco mosaic virus

The interaction of laser pulses with tobacco mosaic virus (TMV) in Tris-HCl pH7.5 buffer and in water has been investigated. Ruby laser pulses of 20 ns duration have been used for excitation. The spectrum of the light passing through the sample was registered with the help of a Fabry–Perot interferometer. In the case of TMV in water we observed in the spectrum only one line of the exciting laser light, but for TMV in Tris-HCl pH7.5 buffer a second line appeared, corresponding to stimulated low-frequency Raman scattering (SLFRS) on the breathing radial mode of TMV. The frequency shift of the SLFRS by 2 cm−1 (60 GHz), the conversion efficiency and the threshold are measured for the first time to the best of our knowledge.

Coherent Excitation of Sodium Chloride Nanoparticles

We register stimulated low-frequency Raman scattering (SLFRS) caused by laser-pulse interaction with nanoparticle acoustic vibrations in an ethanol suspension of sodium chloride nanoparticles and measure the SLFRS conversion efficiency and threshold. Frequency shifts of scattered light from the exciting light frequency are situated in the gigahertz range. We show that the frequency shifts increase with decrease in the nanoparticle sizes.

Experimental observation of stimulated low-frequency Raman scattering in water suspensions of silver and gold nanoparticles

In this Letter we report on experimental observation of stimulated low-frequency Raman scattering (SLFRS) in gold and silver nanoparticle suspensions excited by 20 ns ruby laser pulses, SLFRS propagated in forward and backward directions with a maximum conversion efficiency up to 20%. Frequency shift for silver nanoparticle suspension was found to be 0.33 THz and for gold nanoparticle suspension 0.435 THz. This type of stimulated scattering of light can be used as an effective source of biharmonic pumping for solving a large number of practical tasks.

Effective acousto-optical interactions in suspensions of nanodiamond particles

We present experimental investigations of interactions of pulsed-laser radiation with colloid suspensions of detonated nanodiamond particles. We register stimulated low-frequency Raman scattering (SLFRS) with high conversion efficiency.

Stimulated low-frequency Raman scattering in nanostructures

A new type of stimulated scattering of light (stimulated low-frequency Raman scattering (SLFRS)) is found. SLFRS appears as a result of interaction of laser pulses with acoustic vibrations of structural elements of nanostructured materials. SLFRS is shown to arise in materials with different compositions and different degrees of morphology, both ordered and random. Frequency shifts of SLFRS components are measured. A number of practical applications of the effect are proposed, in particular, biharmonic pumping with the help of SLFRS.