Rapid multiple-quantum three-dimensional fluorescence spectroscopy disentangles quantum pathways

Abstract

Coherent two-dimensional spectroscopy is a powerful tool for probing ultrafast quantum dynamics in complex systems. Several variants offer different types of information but typically require distinct beam geometries. Here we introduce population-based three-dimensional (3D) electronic spectroscopy and demonstrate the extraction of all fourth- and multiple sixth-order nonlinear signal contributions by employing 125-fold (1⨯5⨯5⨯5) phase cycling of a four-pulse sequence. Utilizing fluorescence detection and shot-to-shot pulse shaping in single-beam geometry, we obtain various 3D spectra of the dianion of TIPS-tetraazapentacene, a fluorophore with limited stability at ambient conditions. From this, we recover previously unknown characteristics of its electronic two-photon state. Rephasing and nonrephasing sixth-order contributions are measured without additional phasing that hampered previous attempts using noncollinear geometries. We systematically resolve all nonlinear signals from the same dataset that can be acquired in 8 min. The approach is generalizable to other incoherent observables such as external photoelectrons, photocurrents, or photoions.

Investigating the electronic structure of confined multiexcitons with nonlinear spectroscopies

“…[114][115][116] Finally, the use of 2Q spectroscopy should enable the study of signals arising from the direct two-photon absorption without contributions from the single-photon absorption spectrum. [117][118][119] VI. CONCLUSION…”

Phase-Modulated Rapid-Scanning Fluorescence-Detected Two-Dimensional Electronic Spectroscopy

“…The simultaneous acquisition of two-quantum 2D spectra could be added to our approach, but would require digitization at considerably higher sampling rates to accommodate the higher frequency modulation of the two-quantum signals. We note that our approach is somewhat analogous to the recent demonstration of Mueller et al in which they used a 125-fold phase-cycling scheme for the collection of multiple multidimensional signals within 8 minutes 26 . Their method employs step-scanning, and the pulse-shaper used to implement the experiment has different bandwidth and repetition rate considerations than our approach.…”

Revealing a full quantum ladder by nonlinear spectroscopy

“…In this paper, the direction towards higherorder nonlinear interactions is considered. The fifthorder coherent spectroscopy has been considered in the IR and the visible region and the complex information on the correlations in quantum systems has been represented in 3DIR [57], 3DES [58][59][60] or 3D fluorescence [61]. By spreading frequencies into the third spectral dimension high-frequency vibronic modes [58], double-exciton resonances [27][28][29] or specific exciton relaxation pathways [59,60] have been revealed.…”