TY  - INPR
A1  - Fersch, Daniel
A1  - Malý, Pavel
A1  - Rühe, Jessica
A1  - Lisinetskii, Victor
A1  - Hensen, Matthias
A1  - Würthner, Frank
A1  - Brixner, Tobias
T1  - Single-Molecule Ultrafast Fluorescence-Detected Pump–Probe Microscopy
N2  - We introduce fluorescence-detected pump–probe microscopy by combining a wavelength-tunable ultrafast laser with a confocal scanning fluorescence microscope, enabling access to the femtosecond time scale on the micrometer spatial scale. In addition, we obtain spectral information from Fourier transformation over excitation pulse-pair time delays. We demonstrate this new approach on a model system of a terrylene bisimide (TBI) dye embedded in a PMMA matrix and acquire the linear excitation spectrum as well as time-dependent pump–probe spectra simultaneously. We then push the technique towards single TBI molecules and analyze the statistical distribution of their excitation spectra. Furthermore, we demonstrate the ultrafast transient evolution of several individual molecules, highlighting their different behavior in contrast to the ensemble due to their individual local environment. By correlating the linear and nonlinear spectra, we assess the effect of the molecular environment on the excited-state energy.
KW  - Fluoreszenz
KW  - Ultrafast spectroscopy
KW  - Single-molecule microscopy
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-313485
ER  - 
TY  - JOUR
A1  - Roeding, Sebastian
A1  - Brixner, Tobias
T1  - Coherent two-dimensional electronic mass spectrometry
JF  - Nature Communications
N2  - 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.
KW  - Atomic and molecular interactions with photons
KW  - Excited states
KW  - Reaction kinetics and dynamics
KW  - Optical spectroscopy
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-226458
VL  - 9
IS  - 2519
ER  -