Compact broadband vibrational sum-frequency generation spectrometer with nonresonant suppression.
A compact broadband vibrational sum-frequency spectroscopy (SFG) apparatus is described to study molecules at surfaces and interfaces. Using an étalon as the frequency narrowing device, the visible pulse has a time-asymmetric profile that allows the user to deeply suppress nonresonant background signals that hinder detection of molecular vibrational resonances. Several features of the spectrometer that, in aggregate, improve signal-to-noise ratios by a large factor are described. The spectrometer features a series of interchangeable prealigned sample holders for different applications. Examples of applications are presented where nonresonant suppression greatly improves the ability to study adsorbates on single-crystal surfaces as a function of rotation about the azimuth, and where the rapid data acquisition abilities of the spectrometer are used to study electrochemical transformations on single-crystal electrodes.
School of Chemical Sciences, University of Illinois at Urbana Champaign, Urbana, IL 61801, USA.
Alexei
A
Lagutchev
Aaron
A
Lozano
Prabuddha
P
Mukherjee
Selezion A
SA
Hambir
Dana D
DD
Dlott
D002248:Carbon Monoxide / Q000737:chemistry; D013055:Spectrophotometry, Infrared / Q000295:instrumentation*; D014732:Vibration
D002248:Carbon Monoxide