10 research outputs found

    Proceedings of the Thirteenth International Conference on Time-Resolved Vibrational Spectroscopy

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    The thirteenth meeting in a long-standing series of “Time-Resolved Vibrational Spectroscopy” (TRVS) conferences was held May 19th to 25th at the Kardinal Döpfner Haus in Freising, Germany, organized by the two Munich Universities - Ludwig-Maximilians-UniversitĂ€t and Technische UniversitĂ€t MĂŒnchen. This international conference continues the illustrious tradition of the original in 1982, which took place in Lake Placid, NY. The series of meetings was initiated by leading, world-renowned experts in the field of ultrafast laser spectroscopy, and is still guided by its founder, Prof. George Atkinson (University of Arizona and Science and Technology Advisor to the Secretary of State). In its current format, the conference contributes to traditional areas of time resolved vibrational spectroscopies including infrared, Raman and related laser methods. It combines them with the most recent developments to gain new information for research and novel technical applications. The scientific program addressed basic science, applied research and advancing novel commercial applications. The thirteenth conference on Time Resolved Vibrational Spectroscopy promoted science in the areas of physics, chemistry and biology with a strong focus on biochemistry and material science. Vibrational spectra are molecule- and bond-specific. Thus, time-resolved vibrational studies provide detailed structural and kinetic information about primary dynamical processes on the picometer length scale. From this perspective, the goal of achieving a complete understanding of complex chemical and physical processes on the molecular level is well pursued by the recent progress in experimental and theoretical vibrational studies. These proceedings collect research papers presented at the TRVS XIII in Freising, German

    New Results on Ultrafast Coherent Excitation of Molecular Vibrations in Liquids

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    Coherent Raman probe scattering experiments are performed to study dynamical processes of polyatomic liquids at 300 K. For single homogeneous transitions the dephasing timeT 2 is readily obtained from time resolved investigations. Spectral studies show an interesting time dependent shift in scattered frequency. After the excitaiton the vibrating molecules are shown to relax freely with their resonance frequency. Multiple, equally spaced transitions exhibit a beating phenomenon which provides the dephasing time and the frequency interval between neighboring vibrational states. Inhomogeneously broadened systems do not allow a ready determination of the dephasing time by the present probing technique. Previous experiments on the subject have to be reconsidered

    On the direct impact of the CO

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    The growing amount of carbon dioxide in the atmosphere is often considered as the dominant factor for the global warming during the past decades. The noted correlation, however, does not answer the question about causality. In addition, the reported temperature data do not display a simple relationship between the monotonic concentration increase from 1880 to 2010 and the non-monotonic temperature rise during the same period. We have performed new measurements for optically thick samples of CO2 and investigate its role for the greenhouse effect on the basis of these spectroscopic data. Using simplified global models the warming of the surface is computed and a relatively modest effect is found, only: from the reported CO2 concentration rise in the atmosphere from 290 to 385 ppmv in 1880 to 2010 we derive a direct temperature rise of 0.26±0.01 K0.26\pm0.01\ \text{K} . Including the simultaneous feedback effect of atmospheric water we still arrive at a minor CO2 contribution of less than 33% to the reported global warming of ∌1.2 K{\sim}1.2\ \text{K} . It is suggested that other factors that are known to influence the greenhouse effect, e.g. air pollution by black carbon should be considered in more detail to fully understand the global temperature change

    The long journey to the laser and its rapid development after 1960

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    The laser, a fascinating new light source with numerous applications in our daily life was first realized some 50 years ago. The principle was initiated in 1916 when Einstein introduced a new concept of radiation-matter-interaction known today as stimulated emission of electromagnetic radiation. It took nearly 40 years before a first practical device based on stimulated emission – the maser – was realized for microwaves in 1954. In 1960, the first laser was operated in the visible. This historical note reports on the way to the laser with its climax in 1960. The subsequent explosive development of new lasers and of fundamental applications is shortly reviewed in the second part of the paper
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