@article{RewitzKeitzlTuchschereretal.2012,
  author    = {Rewitz, Christian and Keitzl, Thomas and Tuchscherer, Philip and Goetz, Sebastian and Geisler, Peter and Razinskas, Gary and Hecht, Bert and Brixner, Tobias},
  title     = {Spectral-interference microscopy for characterization of functional plasmonic elements},
  series = {Optics Express},
  journal   = {Optics Express},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85922},
  year      = {2012},
  abstract  = {Plasmonic modes supported by noble-metal nanostructures offer strong subwavelength electric-field confinement and promise the realization of nanometer-scale integrated optical circuits with well-defined functionality. In order to measure the spectral and spatial response functions of such plasmonic elements, we combine a confocal microscope setup with spectral interferometry detection. The setup, data acquisition, and data evaluation are discussed in detail by means of exemplary experiments involving propagating plasmons transmitted through silver nanowires. By considering and experimentally calibrating any setup-inherent signal delay with an accuracy of 1 fs, we are able to extract correct timing information of propagating plasmons. The method can be applied, e.g., to determine the dispersion and group velocity of propagating plasmons in nanostructures, and can be extended towards the investigation of nonlinear phenomena.},
  language  = {en}
}
@article{SteinbacherBubackNuernbergeretal.2012,
  author    = {Steinbacher, Andreas and Buback, Johannes and N{\"u}rnberger, Patrick and Brixner, Tobias},
  title     = {Precise and rapid detection of optical activity for accumulative femtosecond spectroscopy},
  series = {Optics Express},
  journal   = {Optics Express},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85913},
  year      = {2012},
  abstract  = {We present polarimetry, i.e. the detection of optical rotation of light polarization, in a configuration suitable for femtosecond spectroscopy. The polarimeter is based on common-path optical heterodyne interferometry and provides fast and highly sensitive detection of rotatory power. Femtosecond pump and polarimeter probe beams are integrated into a recently developed accumulative technique that further enhances sensitivity with respect to single-pulse methods. The high speed of the polarimeter affords optical rotation detection during the pump-pulse illumination period of a few seconds. We illustrate the concept on the photodissociation of the enantiomers of methyl p-tolyl sulfoxide. The sensitivity of rotatory detection, i.e. the minimum rotation angle that can be measured, is determined experimentally including all noise sources to be 0.10 milli-degrees for a measurement time of only one second and an interaction length of 250 μm. The suitability of the presented setup for femtosecond studies is demonstrated in a non-resonant two-photon photodissociation experiment.},
  language  = {en}
}
@article{AeschlimannBauerBayeretal.2012,
  author    = {Aeschlimann, Martin and Bauer, Michael and Bayer, Daniela and Brixner, Tobias and Cunovic, Stefan and Fischer, Alexander and Melchior, Pascal and Pfeiffer, Walter and Rohmer, Martin and Schneider, Christian and Str{\"u}ber, Christian and Tuchscherer, Philip and Voronine, Dimitri V.},
  title     = {Optimal open-loop near-field control of plasmonic nanostructures},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75256},
  year      = {2012},
  abstract  = {Optimal open-loop control, i.e. the application of an analytically derived control rule, is demonstrated for nanooptical excitations using polarization-shaped laser pulses. Optimal spatial near-field localization in gold nanoprisms and excitation switching is realized by applying a shift to the relative phase of the two polarization components. The achieved near-field switching confirms theoretical predictions, proves the applicability of predefined control rules in nanooptical light-matter interaction and reveals local mode interference to be an important control mechanism.},
  subject      = {Chemie},
  language  = {en}
}
@article{AeschlimannBrixnerCinchettietal.2017,
  author    = {Aeschlimann, Martin and Brixner, Tobias and Cinchetti, Mirko and Frisch, Benjamin and Hecht, Bert and Hensen, Matthias and Huber, Bernhard and Kramer, Christian and Krauss, Enno and Loeber, Thomas H. and Pfeiffer, Walter and Piecuch, Martin and Thielen, Philip},
  title     = {Cavity-assisted ultrafast long-range periodic energy transfer between plasmonic nanoantennas},
  series = {Light: Science \& Applications},
  volume    = {6},
  journal   = {Light: Science \& Applications},
  doi       = {10.1038/lsa.2017.111},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-173265},
  year      = {2017},
  abstract  = {Radiationless energy transfer is at the core of diverse phenomena, such as light harvesting in photosynthesis\(^1\), energy-transfer-based microspectroscopies\(^2\), nanoscale quantum entanglement\(^3\) and photonic-mode hybridization\(^4\). Typically, the transfer is efficient only for separations that are much shorter than the diffraction limit. This hampers its application in optical communication and quantum information processing, which require spatially selective addressing. Here, we demonstrate highly efficient radiationless coherent energy transfer over a distance of twice the excitation wavelength by combining localized and delocalized\(^5\) plasmonic modes. Analogous to the Tavis-Cummings model, two whispering-gallery-mode antennas\(^6\) placed in the foci of an elliptical plasmonic cavity\(^7\) fabricated from single-crystal gold plates act as a pair of oscillators coupled to a common cavity mode. Time-resolved two-photon photoemission electron microscopy (TR 2P-PEEM) reveals an ultrafast long-range periodic energy transfer in accordance with the simulations. Our observations open perspectives for the optimization and tailoring of mesoscopic energy transfer and long-range quantum emitter coupling.},
  language  = {en}
}
@article{RoedingBrixner2018,
  author    = {Roeding, Sebastian and Brixner, Tobias},
  title     = {Coherent two-dimensional electronic mass spectrometry},
  series = {Nature Communications},
  volume    = {9},
  journal   = {Nature Communications},
  number    = {2519},
  doi       = {10.1038/s41467-018-04927-w},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226458},
  pages     = {1-9},
  year      = {2018},
  abstract  = {Coherent two-dimensional (2D) optical spectroscopy has revolutionized our ability to probe many types of couplings and ultrafast dynamics in complex quantum systems. The dynamics and function of any quantum system strongly depend on couplings to the environment. Thus, studying coherent interactions for different environments remains a topic of tremendous interest. Here we introduce coherent 2D electronic mass spectrometry that allows 2D measurements on effusive molecular beams and thus on quantum systems with minimum system-bath interaction and employ this to identify the major ionization pathway of 3d Rydberg states in NO2. Furthermore, we present 2D spectra of multiphoton ionization, disclosing distinct differences in the nonlinear response functions leading to the ionization products. We also realize the equivalent of spectrally resolved transient-absorption measurements without the necessity for acquiring weak absorption changes. Using time-of-flight detection introduces cations as an observable, enabling the 2D spectroscopic study on isolated systems of photophysical and photochemical reactions.},
  language  = {en}
}
@article{MalyBrixner2021,
  author    = {Mal{\´y}, Pavel and Brixner, Tobias},
  title     = {Fluorescence-Detected Pump-Probe Spectroscopy},
  series = {Angewandte Chemie International Edition},
  volume    = {60},
  journal   = {Angewandte Chemie International Edition},
  number    = {34},
  doi       = {10.1002/anie.202102901},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-244811},
  pages     = {18867 -- 18875},
  year      = {2021},
  abstract  = {We introduce a new approach to transient spectroscopy, fluorescence-detected pump-probe (F-PP) spectroscopy, that overcomes several limitations of traditional PP. F-PP suppresses excited-state absorption, provides background-free detection, removes artifacts resulting from pump-pulse scattering, from non-resonant solvent response, or from coherent pulse overlap, and allows unique extraction of excited-state dynamics under certain conditions. Despite incoherent detection, time resolution of F-PP is given by the duration of the laser pulses, independent of the fluorescence lifetime. We describe the working principle of F-PP and provide its theoretical description. Then we illustrate specific features of F-PP by direct comparison with PP, theoretically and experimentally. For this purpose, we investigate, with both techniques, a molecular squaraine heterodimer, core-shell CdSe/ZnS quantum dots, and fluorescent protein mCherry. F-PP is broadly applicable to chemical systems in various environments and in different spectral regimes.},
  language  = {en}
}
@unpublished{DietzschJayachandranMuelleretal.2023,
  author    = {Dietzsch, Julia and Jayachandran, Ajay and Mueller, Stefan and H{\"o}bartner, Claudia and Brixner, Tobias},
  title     = {Excitonic coupling of RNA-templated merocyanine dimer studied by higher-order transient absorption spectroscopy},
  series = {Chemical Communications},
  journal   = {Chemical Communications},
  edition   = {submitted version},
  doi       = {10.1039/D3CC02024J},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-327772},
  year      = {2023},
  abstract  = {We report the synthesis and spectroscopic analysis of RNA containing the barbituric acid merocyanine rBAM2 as a nucleobase surrogate. Incorporation into RNA strands by solid-phase synthesis leads to fluorescence enhancement compared to the free chromophore. In addition, linear absorption studies show the formation of an excitonically coupled H-type dimer in the hybridized duplex. Ultrafast third- and fifth-order transient absorption spectroscopy of this non-fluorescent dimer suggests immediate (sub-200 fs) exciton transfer and annihilation due to the proximity of the rBAM2 units.},
  language  = {en}
}
@article{DostalFennelKochetal.2018,
  author    = {Dost{\´a}l, Jakub and Fennel, Franziska and Koch, Federico and Herbst, Stefanie and W{\"u}rthner, Frank and Brixner, Tobias},
  title     = {Direct observation of exciton-exciton interactions},
  series = {Nature Communications},
  volume    = {9},
  journal   = {Nature Communications},
  doi       = {10.1038/s41467-018-04884-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226271},
  year      = {2018},
  abstract  = {Natural light harvesting as well as optoelectronic and photovoltaic devices depend on efficient transport of energy following photoexcitation. Using common spectroscopic methods, however, it is challenging to discriminate one-exciton dynamics from multi-exciton interactions that arise when more than one excitation is present in the system. Here we introduce a coherent two-dimensional spectroscopic method that provides a signal only in case that the presence of one exciton influences the behavior of another one. Exemplarily, we monitor exciton diffusion by annihilation in a perylene bisimide-based J-aggregate. We determine quantitatively the exciton diffusion constant from exciton-exciton-interaction 2D spectra and reconstruct the annihilation-free dynamics for large pump powers. The latter enables for ultrafast spectroscopy at much higher intensities than conventionally possible and thus improves signal-to-noise ratios for multichromophore systems; the former recovers spatio-temporal dynamics for a broad range of phenomena in which exciton interactions are present.},
  language  = {en}
}