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Abstract Fluorescence lifetime imaging microscopy (FLIM) is a well-established technique with numerous imaging applications. Yet, one of the limitations of FLIM is that it only provides information about the emitting state. Here, we present an extension of FLIM by interferometric measurement of fluorescence excitation spectra. Interferometric Excitation Fluorescence Lifetime Imaging Microscopy (ixFLIM) reports on the correlation of the excitation spectra and emission lifetime, providing the correlation between the ground-state absorption and excited-state emission. As such, it extends the applicability of FLIM and removes some of its limitations. We introduce ixFLIM on progressively more complex systems, directly compare it to standard FLIM, and apply it to quantitative resonance energy transfer imaging from a single measurement.

(Ga,Mn)As is at the forefront of spintronics research exploring the synergy of ferromagnetism with the physics and the technology of semiconductors. However, the electronic structure of this model spintronics material has been debated and the systematic and reproducible control of the basic micromagnetic parameters and semiconducting doping trends has not been established. Here we show that seemingly small departures from the individually optimized synthesis protocols yield non-systematic doping trends, extrinsic charge and moment compensation, and inhomogeneities that conceal intrinsic properties of (Ga,Mn)As. On the other hand, we demonstrate reproducible, well controlled and microscopically understood semiconducting doping trends and micromagnetic parameters in our series of carefully optimized epilayers. Hand-in-hand with the optimization of the material synthesis, we have developed experimental capabilities based on the magneto-optical pump-and-probe method that allowed us to simultaneously determine the magnetic anisotropy, Gilbert damping and spin stiffness constants from one consistent set of measured data. [ABSTRACT FROM AUTHOR]

Here, the authors use atomic force microscopy under ultra-high vacuum conditions to study intramolecular single electron transfer within a single molecule. This allows them to investigate energy dissipation process related to the electron transfer as a function of temperature.

Multidimensional spectroscopic tools are important to explore the details of molecular dynamics. Here the authors use shaped pulses to demonstrate a 3D fluorescence spectroscopy method to extract the fourth and higher-order nonlinear responses in light-molecule interaction.

Light-harvesting antennas and efficient energy transfer enable photosynthesis in low light conditions in natural systems. Here the authors resolve exciton properties and the role of structural hierarchy in a model light-harvesting complex by excited-state 2D spectroscopy on a microfluidic platform.