Raman scattering in dried DNA and crystalline amino acids

Raman spectrum characteristics of dried deoxyribonucleic acid (DNA) and two types of crystalline amino acids (L-lysine, D-asparagine) are compared in a wide range of frequencies, including the regions of lattice (7 to 200 cm^?1) and intramolecular (200 to 4000 cm^?1) vibrations. It is found that the spectral position of the low-frequency band in the Raman spectrum of DNA with a peak near 26 cm^?1 correlates with the Raman spectrum of high-Q low-frequency modes that manifest themselves in the crystalline amino acids under investigation. The low-frequency band of DNA refers to a twist-like vibrational mode of nucleobases. The intensities of this DNA mode and the high-Q lattice modes of the crystalline amino acids L-lysine and D-asparagine are several times as high as those of the Raman lines corresponding to the intramolecular modes. Resonant coupling of low-frequency modes of DNA and amino acid molecular chains is analyzed.     

Raman Scattering in Three-Dimensional Photonic Crystals

The optical properties of three-dimensional photonic crystals associated with the form of reflection spectra from their surface (appearance of a forbidden gap in the energy spectrum) and with the specific features of Raman scattering are analyzed. Idealized models of the energy band structure of photonic crystals are studied. Expressions for the group velocity of photons with energy close to the forbidden gap are derived. Experimental results on the Raman scattering in photonic crystals based on artificial opal as well as in fused silica are discussed. Bands due to quantum-size effects (presence of nanoclusters in fused silica and nanoglobules forming the lattice of globular photonic crystals) were manifested in the spectra of inelastic light scattering. It is proposed to use photonic crystals for the creation of sensitive sensors of organic and inorganic substances using modern Raman techniques.     

Digital multimeasuring systems. Old view to new problems

By the example of experiments performed for a month before writing this paper, some features of measurement automation are considered, and solutions to some “unusual” problems using conventional methods of experiment automation are proposed. Simple circuitries using inexpensive available electronic components whose characteristics can be found in the literature accessible for non-specialists were developed [1, 2]. Some physical results obtained using the described system are considered.     

Reflection Spectra of Composite Photonic Crystals Based on Anodic Alumina Filled with Ferroelectric Sodium Nitrite

Physics of Wave Phenomena - Reflection spectra of a composite one-dimensional photonic crystal (PC) based on porous anodic alumina filled with ferroelectric sodium nitrite have been recorded in the...     

Stimulated Raman Scattering of Light in Glycerol under Picosecond Laser Excitation

Journal of Russian Laser Research - We record stimulated Raman scattering spectra in chemically-pure glycerol with the formation of two Stokes satellites with equidistant Raman frequencies ν =...     

Angular Dependences of Transmission Spectra of Photonic-Crystal Films Based on Aluminum Oxide

Optics and Spectroscopy - The angular dependences of the transmission of a one-dimensional photonic crystal based on porous anodic aluminum oxide are studied in the wavelength range of...     

Three-dimensional quantum photonic crystals and quantum photonic glasses

The structure and optical properties of quantum-dot photonic crystals (quantytes) were studied. Such crystals have the so-called band gaps, which leads to a strong reflection of electromagnetic waves from the crystal surface. It was shown that in certain spectral regions the refractive index has a negative sign, and the group velocity of electromagnetic waves essentially decreases. The applications of quantytes as optical information recording and rewriting devices, negative refractive optical elements, selective mirrors, narrowband filters, and others were discussed.     

富勒稀纳米颗粒的拉曼光散射(英文)

pacc:7560J,7830WepresentresultsofRamanscatteringspec trainvestigationsinfluoroorganicnanoparticles:longzigzagmoleculesCnF2n 2withdifferentn valueandultradispersivefluoroorganicpowder.Ramanspectrahavebeenrecordedforlow-frequencyregion(0-200cm-1),whereres o…     

Raman Scattering in Light and Heavy Waters

We present the results of an experimental study of the spontaneous and stimulated Raman scattering (SRS) spectra and luminescence spectra of light and heavy waters. Also we investigate various samples of light water. We show the possibility of using spectral methods to detect impurities in water and determine the degree of its structuredness, which can serve as an additional criterion of the water quality. We find a fine structure in the SRS spectrum of heavy water in the low-frequency region.     

球状晶体中的拉曼散射和布拉格衍射(英文)

The results of optical properties investigations for some types of globular crystals, including artifical opals and amorphous substances, constructed from the globular nanoclusters are represented. The spectra of light reflection from the surface of received opals have investigated at different incident angle（under mirror-reflection geometry）： 0, 20, 30, 45 and 60 degree.