Search results for "laser"
showing 10 items of 3161 documents
Cavity Ring-Down Spectroscopy measurements of Acetone concentration
2017
This research has been partly supported by the National Research Programme "The next generation of information and communication technologies" (NexIT).
Fundamentals of metastability exchange optical pumping in helium
2010
21 pages; International audience; Advances in metastability exchange optical pumping (MEOP) at high laser powers, but also at high gas pressures and high magnetic field strengths, has provided strong motivation for revisiting the understanding of the limitations of this powerful technique. A comprehensive model has been developped for improved description of the combined effects of OP, ME, and relaxation, and of detailed MEOP features observed over the broad range of operating conditions. A brief description is provided, with illustrative comparisons of computed and experimental results. This improved tool is used to explain the excellent photon efficiency of OP obtained at all field streng…
The next generation of laser spectroscopy experiments using light muonic atoms
2018
Precision spectroscopy of light muonic atoms provides unique information about the atomic and nuclear structure of these systems and thus represents a way to access fundamental interactions, properties and constants. One application comprises the determination of absolute nuclear charge radii with unprecedented accuracy from measurements of the 2S - 2P Lamb shift. Here, we review recent results of nuclear charge radii extracted from muonic hydrogen and helium spectroscopy and present experiment proposals to access light muonic atoms with Z ≥ 3. In addition, our approaches towards a precise measurement of the Zemach radii in muonic hydrogen (μp) and helium (μ 3He+) are discussed. These resul…
Application of micro Raman spectroscopy to industrial FC membranes
2007
Raman spectra of as-received and protonated membranes (Nafion® NRE-212, Fumapem® F-14100 and Fumasep® FAA) were measured with He-Cd and Ar laser. For the first time the Raman and IR spectra are reported of Fumasep membranes. Most of peaks in vibration spectra active in Raman and IR of membranes are interpreted with C-F, C-S, C-O-C, SO3, C-C bonds. The vibration region connected with protons and H-O bond in both types of membranes is found in Raman and IR spectra.
Laser spectroscopy of gallium isotopes beyond N = 50
2012
The installation of an ion-beam cooler-buncher at the ISOLDE, CERN facility has provided increased sensitivity for collinear laser spectroscopy experiments. A migration of single-particle states in gallium and in copper isotopes has been investigated through extensive measurements of ground state and isomeric state hyperfine structures. Lying beyond the N = 50 shell closure, 82Ga is the most exotic nucleus in the region to have been studied by optical methods, and is reported here for the first time. ispartof: pages:012071-6 ispartof: Journal of Physics: Conference Series vol:381 issue:1 pages:012071-6 ispartof: Rutherford Centennial Conference on Nuclear Physics location:Manchester, UK dat…
Early onset of deformation in the neutron-deficient polonium isotopes
2012
In-source laser spectroscopy has been performed at CERN-ISOLDE with the RILIS laser ion source on Po-191-204,Po-206,Po-208-211,Po-216,Po-218. New information on the beta decay of Po-199 were extracted in the process, challenging previous results. Large-scale atomic calculations were performed to extract the changes in the mean-square charge radius delta from the isotope shifts. The delta for the even-A isotopes reveal a large deviation from the spherical droplet model for N < 116.
Obtaining of nanostructured ZnO coatings using mechanoactivated oxidation
2007
The concept to use nanostructured state of metal at the instant of destruction in air environment was used to obtain nanostructured Zn-ZnO coatings on glass and quartz by mechanical method. Subsequent annealing in the ambient atmosphere, annealing in vacuum and irradiation with 532-nm YAG:Nd laser were used to obtain completely oxidized, transparent ZnO coatings. The saturated with oxygen nanostructured coatings were transformed into nanostructured ZnO coatings after annealing above 773K or irradiation with laser (allowing to reach 673K) in ambient atmosphere. AFM and SEM images show that after annealing ZnO coatings have multi-shaped structure. The formation of ZnO need-like whiskers (d = …
Riga Group’s recent results on laser applications for skin diagnostics
2021
Abstract The laser-related activities are reviewed of the Biophotonics Laboratory at UL Institute of Atomic Physics and Spectroscopy following the previous ICSQE-2018 conference. Four recent research projects are considered, including one EC Horizon-2020 project, two European Regional Development Fund (ERDF) projects and one project funded by the Latvian Council of Science (LCS). The projects are generally aimed at developing new optical methods and technologies for non-invasive in-vivo skin assessment to facilitate the early diagnostics of skin malformations (including cancers). Most of the projects explore novel approaches of camera-based biomedical imaging to the clinical diagnostics and…
Thermo-optical studies of NaNbO3thin films
2007
Thermo-optical studies of sodium niobate NaNbO3 (NN) thin films, deposited by the pulsed laser ablation technique on Si/SrRuO3 substrates, were performed by spectroscopic ellipsometry in the temperature range 300-550°C. Optical constants at the room temperature were measured in the spectral range 250-1000 nm. Substantial changes in the refractive index temperature behaviour (taken at λ = 300 nm) were found at temperatures 370, 445, 503, 520, and 532°C, where the first and the last temperatures are the phase transitions P → R and S → T1, respectively. Other temperatures (445, 503, and 520°C) are suggested as the points of some local structural changes in the NN film.
Line shape measurements of rubidium 5S-7S two-photon transition
2014
We report the use of a digital lock to measure the line profile and center frequency of rubidium 5S-7S two-photon transitions with a cw laser referenced to an optical frequency comb. The narrow, two-photon transition, 5S-7S (760 nm), insensitive to first-order in a magnetic field, is a promising candidate for frequency reference.