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There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
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Prof. Alexander Benderskii, Wayne State University
Coherent Surface-Selective Vibrational Spectroscopy in Frequency- and Time-Domain
Recent developments in frequency- and time-resolved surface-selective nonlinear optical spectroscopies will be discussed. These techniques are capable of providing insight into the molecular structure, orientation, and ultrafast dynamics at surfaces and interfaces. In particular, various time- and frequency-domain versions of the 3-wave mixing (IR+visible Sum Frequency Generation, SFG) will be presented as the lowest-order nonlinear technique that is both surface-selective and capable of measuring vibrational coherences. Obtaining maximum information from the spectroscopic measurements will be considered, in terms of extraction of amplitude and phase of the signal, and enhancing sensitivity and detection limits using optical heterodyne detection (HD-SFG). Several applications will be discussed (time permitting), including: (1) Hydrogen bonding dynamics at aqueous interfaces investigated using Spectrally- and Time-Resolved SFG (STiR-SFG), a new technique measuring spectral evolution of vibrational coherences on the 50-150 fs time scale indicating ultrafast H-bond rearrangement at interfaces; (2) Molecular organization in Langmuir-Blodgett organic monolayers, including the coherent vibrational quantum beats measured in time-domain using SFG Free Induction Decay spectroscopy; (3) Molecular conformation at nanoparticle surfaces, and how it changes when the particle size approaches the molecular size.
For more information contact Dr. Robert Dickson (404-894-4007).
