Del Mar Photonics - Newsletter Fall 2010 - Newsletter Winter 2010

Sample cells for probing solid/liquid interfaces with broadband sum-frequency-generation spectroscopy (pdf)
 

Dominique Verreault, Volker Kurz, Caitlin Howell, and Patrick Koelscha
Department of Applied Physical Chemistry, University of Heidelberg, Im Neuenheimer Feld 253, D-69120
Heidelberg, Germany and Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology,
Campus North, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany

Two sample cells designed specifically for sum-frequency-generation SFG measurements at the solid/liquid interface were developed: one thin-layer analysis cell allowing measurement of films on reflective metallic surfaces through a micrometer layer of solution and one spectroelectrochemical cell allowing investigation of processes at the indium tin oxide/solution interface. Both sample cells are described in detail and data illustrating the capabilities of each are shown. To further improve measurements at solid/liquid interfaces, the broadband SFG system was modified to include a reference beam which can be measured simultaneously with the sample signal, permitting
background correction of SFG spectra in real time. Sensitivity tests of this system yielded a signal-to-noise ratio of 100 at a surface coverage of 0.2 molecules/nm2. Details on data analysis routines, pulse shaping methods of the visible beam, as well as the design of a purging chamber and sample stage setup are presented. These descriptions will be useful to those planning to set up a SFG spectrometer or seeking to optimize their own SFG systems for measurements of solid/liquid interfaces.

Calcium Fluoride Optics for SFG Spectroscopy

Del Mar Photonics supplies lasers and systems based on cost effective femtosecond sources for Sum-frequency-Generation Spectroscopy - request a quote