Research

Probing dynamics and structure of molecules using laser spectroscopy: One area of active research is the study of dynamics, structure and bond cleavage in gas phase molecules utilizing pulsed lasers. These characteristics are probed via spectral signatures of the species with various spectroscopies, employing tunable lasers spanning the infrared, visible and ultraviolet regions of the spectrum. In particular, we seek for the possibility of controlling bond fission via energy deposition in different skeletal motions of molecules. The major goals are to find ways for selecting desired pathways, for altering state distributions, for developing an understanding regarding vibrational energy flow within molecules, and for finding non-statistical behaviour so that it can be predicted and may be even controlled by lasers.

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Development of a new spectroscopic method for the study of floppy biomolecules: Due to the crucial role that conformations and shapes of molecular constituents involved in biological processes play in determining their selectivity and functionality, the exploration of these properties is thus a prerequisite for gaining molecular-level understanding of the complex dynamics of these processes. Structures and interactions of biomolecules are of fundamental importance in elucidating the mechanisms of biological processes and might have implications on designing drugs that mimic, activate or suppress the function of bioactive systems.

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Detection of explosives: Rapid detection of hazardous materials, particularly explosives, turns to be an increasingly important task, requiring additional approaches for remote detection of certain molecular species. Vibrational spectroscopy is well suited for their identification, providing spectral signatures and recognition of specific compounds. We try to use spontaneous Raman and coherent anti-Stokes Raman scattering (CARS) spectroscopies to detect solid particles of explosives and related compounds and particularly to assess the conditions for obtaining higher sensitivities.

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Nonlinear optics: Industrial, biomedical and military applications require wavelengths differing from those of the fundamental outputs of available standard lasers. Since alternative laser gain media do not always exist, different nonlinear processes are employed to efficiently convert the frequency from accessible spectral regions to those where they are scarce. One of these conversion processes is based on stimulated Raman scattering (SRS) – that allows generation of longer wavelengths by inelastic scattering of light in a medium. In this project we focus on shifting the second harmonic of a Nd:YAG laser (532 nm) in water in attempt to find the optimal conditions for SRS generation.

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Tailored nanoparticles, by laser ablation of metal and bimetal targets: Hydrogenation processes are most important for future hydrogen based fuels and other industrial applications, including hydrogen storage, hydrogen trapping for safe handling and separation of hydrogen based molecules. In most of these processes the main rate determining reaction is the dissociation of the hydrogen molecule, which can be controlled by nanoparticles (NPs) that act as catalysts. Consequently, NPs will be prepared via laser ablation in liquids, by using different targets of bulk metals, alloys and particles suspended in liquids, under different ablation conditions. State-of-the art characterization methods, will reveal the structures and characteristics of the resulting NPs and assess their potential for catalytic purposes.