Time-resolved resonance fluorescence spectroscopy for study of chemical reactions in laser-induced plasmas

Abstract

Identification of chemical intermediates and study of chemical reaction pathways and mechanisms in laser-induced plasmas are important for laser-ablated applications. Laser-induced breakdown spectroscopy (LIBS), as a promising spectroscopic technique, is efficient for elemental analyses but can only provide limited information about chemical products in laser-induced plasmas. In this work, time-resolved resonance fluorescence spectroscopy was studied as a promising tool for the study of chemical reactions in laser-induced plasmas. Resonance fluorescence excitation of diatomic aluminum monoxide (AlO) and triatomic dialuminum monoxide (AlO) was used to identify these chemical intermediates. Time-resolved fluorescence spectra of AlO and AlO were used to observe the temporal evolution in laser-induced Al plasmas and to study their formation in the Al-O chemistry in air.

The SuperCam Instrument Suite on the Mars 2020 Rover: Science Objectives and Mast-Unit Description

“…Fluorescence time scales are typically on the order of nanoseconds for organics while they can be much longer, from micro-to milliseconds, for most emission centers in minerals (Liu et al 2017). Phosphorescence occurs via a similar mechanism, but it involves electronic transitions between states of differing spin.…”

Ro-vibrational Spectrum of Linear Dialuminum Monoxide (Al2O) at 10 μm

“…In 2017, a study on chemical reaction pathways in an aluminum laser ablation plasma was performed by means of laser-induced breakdown spectroscopy . From the fluorescence spectra it was concluded that Al 2 O forms at later times than AlO, indicating a bottom-up principle in the formation of larger aluminum-containing molecules.…”