Three dimensional vibrational spectroscopy
Home page Contact us Directions for visitors Research Projects Dana D. Dlott (Curriculum Vitae) Dana D. Dlott (personal home page) David M. Dlott (personal home page) Group Members Research Publications Research Funding Research Facilities	Vibrational spectroscopy (Infrared and Raman) is widely used for chemical analysis.  Conventional IR and Raman systems use continuous light sources. The newest multidimensional and coherent vibrational spectroscopy techniques use short pulses. Quite a few groups worldwide are working on multidimensional IR spectroscopy techniques that are the analog of pulsed NMR experiments. The Dlott group is a leader in the development of new pulsed vibrational spectroscopic techniques.  Ultrafast coherent Raman scattering and ultrafast IR spectroscopies are being developed and used to study dynamical processes in condensed matter. In our three-dimensional vibrational spectroscopy experiments, a sample is excited by a short-duration IR pump pulse, and then probed by a visible pulse that generates an incoherent Raman spectrum. The three dimensions are IR pump frequency, Raman probe frequency and time delay. With this technique, we can study vibrational energy in more detail than has ever been possible. We can input energy to a specific vibrational state and watch where it goes. In some cases we have both picosecond time resolution and angstrom spatial resolution. For instance in ethanol, OH-CH2-CH3, we can pump energy into the OH stretch and watch it travel down the molecule, through the methylene –CH2- to the methyl –CH3. In the future we will use this technique to study vibrational energy in other liquids, at low temperature, in nanostructures and in biological systems.	Apparatus for 3D vibrational spectroscopy in Dlott labs Optical parametric amplifiers produce femtosecond IR and visible pulses at 1 kilohertz repetition rate Experimental arrangement for 3D spectroscopy