Fluorescence-detected pump-probe (F-PP) spectroscopy is a recently developed method to study excited-state dynamics. F-PP combines the temporal resolution of conventional transient absorption (TA) spectroscopy with the sensitivity of fluorescence detection. In this work, we demonstrate inherently phase-stable F-PP spectroscopy using 20 fs pulses to monitor the ultrafast Stokes shift dynamics of a solvated fluorophore (Y12). We observed a shift in the stimulated emission maximum with a time constant of 84 fs. In contrast to TA, F-PP provides a coherent artifact-free view of this process. Using quantitative signal background subtraction, as discussed in this work, F-PP uncovers the pure stimulated emission spectrum and its ultrafast dynamics. This signal isolation is a clear advantage over TA, where different contributions often overlap heavily. We compare results from F-PP and TA on an equal footing using the same excitation pulses, emphasizing the features and advantages of the F-PP technique.

Faculty of Mathematics and Physics Institute of Physics Charles University Ke Karlovu 5 121 16 Praha 2 Czech Republic

Professorship of Dynamic Spectroscopy Department of Chemistry TUM School of Natural Sciences Technical University of Munich Lichtenbergstraße 4 85748 Garching Germany

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Berera R., van Grondelle R., Kennis J. T. M.. Ultrafast transient absorption spectroscopy: principles and application to photosynthetic systems. Photosynth. Res. 2009;101:105–118. doi: 10.1007/s11120-009-9454-y. PubMed DOI PMC

Pattengale B., Ostresh S., Schmuttenmaer C. A., Neu J.. Interrogating Light-initiated Dynamics in Metal-Organic Frameworks with Time-resolved Spectroscopy. Chem. Rev. 2022;122:132–166. doi: 10.1021/acs.chemrev.1c00528. PubMed DOI

Young R. M., Wasielewski M. R.. Mixed Electronic States in Molecular Dimers: Connecting Singlet Fission, Excimer Formation, and Symmetry-Breaking Charge Transfer. Acc. Chem. Res. 2020;53:1957–1968. doi: 10.1021/acs.accounts.0c00397. PubMed DOI

Knowles K. E., Koch M. D., Shelton J. L.. Three applications of ultrafast transient absorption spectroscopy of semiconductor thin films: spectroelectrochemistry, microscopy, and identification of thermal contributions. J. Mater. Chem. C. 2018;6:11853–11867. doi: 10.1039/C8TC02977F. DOI

Maly P., Brixner T.. Fluorescence-Detected Pump-Probe Spectroscopy. Angew. Chem., Int. Ed. Engl. 2021;60:18867–18875. doi: 10.1002/anie.202102901. PubMed DOI PMC

Fersch D., Malý P., Rühe J., Lisinetskii V., Hensen M., Würthner F., Brixner T.. Single-Molecule Ultrafast Fluorescence-Detected Pump-Probe Microscopy. J. Phys. Chem. Lett. 2023;14:4923–4932. doi: 10.1021/acs.jpclett.3c00839. PubMed DOI

Tiwari V., Matutes Y. A., Gardiner A. T., Jansen T. L. C., Cogdell R. J., Ogilvie J. P.. Spatially-resolved fluorescence-detected two-dimensional electronic spectroscopy probes varying excitonic structure in photosynthetic bacteria. Nat. Commun. 2018;9:4219. doi: 10.1038/s41467-018-06619-x. PubMed DOI PMC

Lott G. A., Perdomo-Ortiz A., Utterback J. K., Widom J. R., Aspuru-Guzik A., Marcus A. H.. Conformation of self-assembled porphyrin dimers in liposome vesicles by phase-modulation 2D fluorescence spectroscopy. Proc. Natl. Acad. Sci. U.S.A. 2011;108:16521–16526. doi: 10.1073/pnas.1017308108. PubMed DOI PMC

Malý P., Lüttig J., Mueller S., Schreck M. H., Lambert C., Brixner T.. Coherently and fluorescence-detected two-dimensional electronic spectroscopy: direct comparison on squaraine dimers. Phys. Chem. Chem. Phys. 2020;22:21222–21237. doi: 10.1039/D0CP03218B. PubMed DOI

Tekavec P. F., Lott G. A., Marcus A. H.. Fluorescence-detected two-dimensional electronic coherence spectroscopy by acousto-optic phase modulation. J. Chem. Phys. 2007;127:214307. doi: 10.1063/1.2800560. PubMed DOI

De A. K., Monahan D., Dawlaty J. M., Fleming G. R.. Two-dimensional fluorescence-detected coherent spectroscopy with absolute phasing by confocal imaging of a dynamic grating and 27-step phase-cycling. J. Chem. Phys. 2014;140:194201. doi: 10.1063/1.4874697. PubMed DOI

Lorenc M., Ziolek M., Naskrecki R., Karolczak J., Kubicki J., Maciejewski A.. Artifacts in femtosecond transient absorption spectroscopy. Appl. Phys. B: Laser Opt. 2002;74:19–27. doi: 10.1007/s003400100750. DOI

Malý P., Mueller S., Lüttig J., Lambert C., Brixner T.. Signatures of exciton dynamics and interaction in coherently and fluorescence-detected four- and six-wave-mixing two-dimensional electronic spectroscopy. J. Chem. Phys. 2020;153:144204. doi: 10.1063/5.0022743. PubMed DOI

Ruberti M., Averbukh V., Mintert F.. Bell Test of Quantum Entanglement in Attosecond Photoionization. Phys. Rev. X. 2024;14:041042. doi: 10.1103/PhysRevX.14.041042. DOI

Hans A., Ozga C., Schmidt P., Hartmann G., Nehls A., Wenzel P., Richter C., Lant C., Holzapfel X., Viehmann J. H.. et al. Setup for multicoincidence experiments of photons in the extreme ultraviolet to visible spectral range and charged particlesThe solid angle maximization approach. Rev. Sci. Instrum. 2019;90:093104. doi: 10.1063/1.5109104. PubMed DOI

Perri A., Preda F., D’Andrea C., Thyrhaug E., Cerullo G., Polli D., Hauer J.. Excitation-emission Fourier-transform spectroscopy based on a birefringent interferometer. Opt. Express. 2017;25:A483–A490. doi: 10.1364/OE.25.00A483. PubMed DOI

Piatkowski L., Gellings E., van Hulst N. F.. Broadband single-molecule excitation spectroscopy. Nat. Commun. 2016;7:10411. doi: 10.1038/ncomms10411. PubMed DOI PMC

Wagner W., Li C., Semmlow J., Warren W. S.. Rapid phase-cycled two-dimensional optical spectroscopy in fluorescence and transmission mode. Opt. Express. 2005;13:3697–3706. doi: 10.1364/OPEX.13.003697. PubMed DOI

Schröter M., Pullerits T., Kühn O.. Using fluorescence detected two-dimensional spectroscopy to investigate initial exciton delocalization between coupled chromophores. J. Chem. Phys. 2018;149:114107. doi: 10.1063/1.5046645. PubMed DOI

Heussman D., Kittell J., von Hippel P. H., Marcus A. H.. Temperature-dependent local conformations and conformational distributions of cyanine dimer labeled single-stranded-double-stranded DNA junctions by 2D fluorescence spectroscopy. J. Chem. Phys. 2022;156:045101. doi: 10.1063/5.0076261. PubMed DOI PMC

Tiwari V., Matutes Y. A., Konar A., Yu Z., Ptaszek M., Bocian D. F., Holten D., Kirmaier C., Ogilvie J. P.. Strongly coupled bacteriochlorin dyad studied using phase-modulated fluorescence-detected two-dimensional electronic spectroscopy. Opt. Express. 2018;26:22327–22341. doi: 10.1364/OE.26.022327. PubMed DOI

Karki K. J., Chen J., Sakurai A., Shi Q., Gardiner A. T., Kühn O., Cogdell R. J., Pullerits T.. Before Förster. Initial excitation in photosynthetic light harvesting. Chem. Sci. 2019;10:7923–7928. doi: 10.1039/C9SC01888C. PubMed DOI PMC

Bolzonello L., Bruschi M., Fresch B., van Hulst N. F.. Nonlinear Optical Spectroscopy of Molecular Assemblies: What Is Gained and Lost in Action Detection? J. Phys. Chem. Lett. 2023;14:11438–11446. doi: 10.1021/acs.jpclett.3c02824. PubMed DOI PMC

Grégoire P., Srimath Kandada A. R., Vella E., Tao C., Leonelli R., Silva C.. Incoherent population mixing contributions to phase-modulation two-dimensional coherent excitation spectra. J. Chem. Phys. 2017;147:114201. doi: 10.1063/1.4994987. PubMed DOI

Faitz Z. M., Im D., Blackwell C. J., Arnold M. S., Zanni M. T.. A spectrometer design that eliminates incoherent mixing signals in 2D action spectroscopies. J. Chem. Phys. 2024;161:134202. doi: 10.1063/5.0229181. PubMed DOI

Javed A., Lüttig J., Charvátová K., Sanders S. E., Willow R., Zhang M., Gardiner A. T., Malý P., Ogilvie J. P.. Photosynthetic Energy Transfer: Missing in Action (Detected Spectroscopy)? J. Phys. Chem. Lett. 2024;15:12376–12386. doi: 10.1021/acs.jpclett.4c02665. PubMed DOI

Charvátová K., Malý P.. Spectro-temporal symmetry in action-detected optical spectroscopy: Highlighting excited-state dynamics in large systems. J. Chem. Phys. 2025;162:124204. doi: 10.1063/5.0255316. PubMed DOI

Sahu A., Bhat V. N., Patra S., Tiwari V.. High-sensitivity fluorescence-detected multidimensional electronic spectroscopy through continuous pump-probe delay scan. J. Chem. Phys. 2023;158:024201. doi: 10.1063/5.0130887. PubMed DOI

Jana S., Durst S., Lippitz M.. Fluorescence-Detected Two-Dimensional Electronic Spectroscopy of a Single Molecule. Nano Lett. 2024;24:12576–12581. doi: 10.1021/acs.nanolett.4c03559. PubMed DOI

Brida D., Manzoni C., Cerullo G.. Phase-locked pulses for two-dimensional spectroscopy by a birefringent delay line. Opt. Lett. 2012;37:3027–3029. doi: 10.1364/OL.37.003027. PubMed DOI

Réhault J., Maiuri M., Oriana A., Cerullo G.. Two-dimensional electronic spectroscopy with birefringent wedges. Rev. Sci. Instrum. 2014;85:123107. doi: 10.1063/1.4902938. PubMed DOI

Thyrhaug E., Krause S., Perri A., Cerullo G., Polli D., Vosch T., Hauer J.. Single-molecule excitation-emission spectroscopy. Proc. Natl. Acad. Sci. U.S.A. 2019;116:4064–4069. doi: 10.1073/pnas.1808290116. PubMed DOI PMC

Réhault J., Crisafi F., Kumar V., Ciardi G., Marangoni M., Cerullo G., Polli D.. Broadband stimulated Raman scattering with Fourier-transform detection. Opt. Express. 2015;23:25235–25246. doi: 10.1364/OE.23.025235. PubMed DOI

Wolz L., Heshmatpour C., Perri A., Polli D., Cerullo G., Finley J. J., Thyrhaug E., Hauer J., Stier A. V.. Time-domain photocurrent spectroscopy based on a common-path birefringent interferometer. Rev. Sci. Instrum. 2020;91:123101. doi: 10.1063/5.0023543. PubMed DOI

Preda F., Oriana A., Réhault J., Lombardi L., Ferrari A. C., Cerullo G., Polli D.. Linear and Nonlinear Spectroscopy by a Common-Path Birefringent Interferometer. IEEE J. Sel. Top. Quantum Electron. 2017;23:88–96. doi: 10.1109/JSTQE.2016.2630840. DOI

Réhault J., Maiuri M., Manzoni C., Brida D., Helbing J., Cerullo G.. 2D IR spectroscopy with phase-locked pulse pairs from a birefringent delay line. Opt. Express. 2014;22:9063–9072. doi: 10.1364/OE.22.009063. PubMed DOI

Timmer D., Lünemann D. C., Riese S., Sio A. D., Lienau C.. Full visible range two-dimensional electronic spectroscopy with high time resolution. Opt. Express. 2024;32:835–847. doi: 10.1364/OE.511906. PubMed DOI

Sanders S. E., Zhang M., Javed A., Ogilvie J. P.. Expanding the bandwidth of fluorescence-detected two-dimensional electronic spectroscopy using a broadband continuum probe pulse pair. Opt. Express. 2024;32:8887–8902. doi: 10.1364/OE.516963. PubMed DOI

Kühn O., Mančal T., Pullerits T.. Interpreting Fluorescence Detected Two-Dimensional Electronic Spectroscopy. J. Phys. Chem. Lett. 2020;11:838–842. doi: 10.1021/acs.jpclett.9b03851. PubMed DOI

van Stokkum I. H. M., Larsen D. S., van Grondelle R.. Global and target analysis of time-resolved spectra. Biochim. Biophys. Acta Bioenerg. 2004;1657:82–104. doi: 10.1016/j.bbabio.2004.04.011. PubMed DOI

Xu Y., Peschel M. T., Jänchen M., Foja R., Storch G., Thyrhaug E., de Vivie-Riedle R., Hauer J.. Determining Excited-State Absorption Properties of a Quinoid Flavin by Polarization-Resolved Transient Spectroscopy. J. Phys. Chem. A. 2024;128:3830–3839. doi: 10.1021/acs.jpca.4c01260. PubMed DOI PMC

Mertz E. L., Tikhomirov V. A., Krishtalik L. I.. Stokes Shift as a Tool for Probing the Solvent Reorganization Energy. J. Phys. Chem. A. 1997;101:3433–3442. doi: 10.1021/jp963042b. DOI

Samanta A.. Dynamic Stokes Shift and Excitation Wavelength Dependent Fluorescence of Dipolar Molecules in Room Temperature Ionic Liquids. J. Phys. Chem. B. 2006;110:13704–13716. doi: 10.1021/jp060441q. PubMed DOI

Samanta A.. Solvation Dynamics in Ionic Liquids: What We Have Learned from the Dynamic Fluorescence Stokes Shift Studies. J. Phys. Chem. Lett. 2010;1:1557–1562. doi: 10.1021/jz100273b. DOI

Sajadi M., Ernsting N. P.. Excess Dynamic Stokes Shift of Molecular Probes in Solution. J. Phys. Chem. B. 2013;117:7675–7684. doi: 10.1021/jp400473n. PubMed DOI

Cui E., Liu H., Wang Z., Chen H., Weng Y.-X.. Femtosecond fluorescence conical optical parametric amplification spectroscopy. Rev. Sci. Instrum. 2024;95:033008. doi: 10.1063/5.0197254. PubMed DOI

Zhao L., Luis Pérez Lustres J., Farztdinov V., Ernsting N. P.. Femtosecond fluorescence spectroscopy by upconversion with tilted gate pulses. Phys. Chem. Chem. Phys. 2005;7:1716–1725. doi: 10.1039/B500108K. PubMed DOI

Schriever C., Lochbrunner S., Krok P., Riedle E.. Tunable pulses from below 300 to 970 nm with durations down to 14 fs based on a 2 MHz ytterbium-doped fiber system. Opt. Lett. 2008;33:192–194. doi: 10.1364/OL.33.000192. PubMed DOI

Ma X., Wang J., Gao J., Hu Z., Xu C., Zhang X., Zhang F.. Achieving 17.4% Efficiency of Ternary Organic Photovoltaics with Two Well-Compatible Nonfullerene Acceptors for Minimizing Energy Loss. Adv. Energy Mater. 2020;10:2001404. doi: 10.1002/aenm.202001404. DOI

Regnier F., Rillaerts A., Lemaur V., Viville P., Cornil J.. The impact of side chain elongation from the Y6 to Y6–12 acceptor in organic solar cells: a fundamental study from molecules to devices. J. Mater. Chem. C. 2023;11:7451–7461. doi: 10.1039/D3TC00666B. DOI

Zou X., Wen G., Hu R., Dong G., Zhang C., Zhang W., Huang H., Dang W.. An Insight into the Excitation States of Small Molecular Semiconductor Y6. Molecules. 2020;25:4118. doi: 10.3390/molecules25184118. PubMed DOI PMC

Li H., Gauthier-Houle A., Grégoire P., Vella E., Silva-Acuña C., Bittner E. R.. Probing polaron excitation spectra in organic semiconductors by photoinduced-absorption-detected two-dimensional coherent spectroscopy. Chem. Phys. 2016;481:281–286. doi: 10.1016/j.chemphys.2016.07.004. DOI

Uhl D., Bangert U., Bruder L., Stienkemeier F.. Coherent optical 2D photoelectron spectroscopy. Optica. 2021;8:1316–1324. doi: 10.1364/OPTICA.434853. DOI

Karki K. J., Widom J. R., Seibt J., Moody I., Lonergan M. C., Pullerits T., Marcus A. H.. Coherent two-dimensional photocurrent spectroscopy in a PbS quantum dot photocell. Nat. Commun. 2014;5:5869. doi: 10.1038/ncomms6869. PubMed DOI

Gerecke M., Bierhance G., Gutmann M., Ernsting N. P., Rosspeintner A.. Femtosecond broadband fluorescence upconversion spectroscopy: Spectral coverage versus efficiency. Rev. Sci. Instrum. 2016;87:053115. doi: 10.1063/1.4948932. PubMed DOI

Wang R., Zhang C., Li Q., Zhang Z., Wang X., Xiao M.. Charge Separation from an Intra-Moiety Intermediate State in the High-Performance PM6:Y6 Organic Photovoltaic Blend. J. Am. Chem. Soc. 2020;142:12751–12759. doi: 10.1021/jacs.0c04890. PubMed DOI

Slavov C., Hartmann H., Wachtveitl J.. Implementation and Evaluation of Data Analysis Strategies for Time-Resolved Optical Spectroscopy. Anal. Chem. 2015;87:2328–2336. doi: 10.1021/ac504348h. PubMed DOI

Zaukevičius A., Jukna V., Antipenkov R., Martinėnaitė V., Varanavičius A., Piskarskas A. P., Valiulis G.. Manifestation of spatial chirp in femtosecond noncollinear optical parametric chirped-pulse amplifier. J. Opt. Soc. Am. B. 2011;28:2902–2908. doi: 10.1364/JOSAB.28.002902. DOI