Broadband cavity-enhanced ultrafast spectroscopy

Broadband ultrafast optical spectroscopy methods, such as transient absorption spectroscopy and 2D spectroscopy, are widely used to study molecular dynamics. However, these techniques are typically restricted to optically thick samples, such as solids and liquid solutions. In this article we discuss a cavity-enhanced ultrafast transient absorption spectrometer covering almost the entire visible range with a detection limit of Delta OD < 1 x 10(-9), extending broadband all-optical ultrafast spectroscopy techniques to dilute beams of gas-phase molecules and clusters. We describe the technical innovations behind the spectrometer and present transient absorption data on two archetypical molecular systems for excited-state intramolecular proton transfer, 1 '-hydroxy-2 '-acetonapthone and salicylideneaniline, under jet-cooled and Ar cluster conditions.

Automated summary

The article discusses a cavity-enhanced ultrafast transient absorption spectrometer, extending broadband all-optical ultrafast spectroscopy techniques to dilute beams of gas-phase molecules and clusters. Technical innovations behind the spectrometer and transient absorption data on two molecular systems for excited-state intramolecular proton transfer are presented.