Vibrational Sum Frequency Generation Spectroscopy of Interfacial Dynamics

This chapter describes recent advances in vibrational sum frequency generation (SFG) instrumentation. It explains the use of advances in two frontier research areas: the study ultrafast dynamics of heat transfer to molecular adsorbates and the study of in situ electrochemical processes occurring at electrode-electrolyte interfaces. The chapter discusses studies of the rearrangements of interfacial molecules caused by a temperature jump (T-jump) created by a laser "pump" pulse. It focuses on the instrumentation for broadband multiplex nonresonant (NR)-suppressed SFG spectroscopy. The use of an Fabry-Perot ètalon in replacement of the more usual optical bandpass filter or zero dispersion spectrograph as the visible bandwidth limiting element allows for NR suppression. The NR suppression technique enabled the authors to study solid-electrolyte interfaces (SEI) formation in lithium ion systems with excellent signal-to-noise ratios. The chapter also discusses the ultrafast temperature jump technique to study the flow of vibrational energy across interfaces and through molecules.