TY  - JOUR
A1  - Kanal, Florian
A1  - Keiber, Sabine
A1  - Eck, Reiner
A1  - Brixner, Tobias
T1  - 100-kHz shot-to-shot broadband data acquisition for high-repetition-rate pump–probe spectroscopy
N2  - Shot-to-shot broadband detection is common in ultrafast pump–probe spectroscopy. Taking advantage of the intensity correlation of subsequent laser pulses improves the signal-to-noise ratio. Finite data readout times of CCD chips in the employed spectrometer and the maximum available speed of mechanical pump-beam choppers typically limit this approach to lasers with repetition rates of a few kHz. For high-repetition (≥ 100 kHz) systems, one typically averages over a larger number of laser shots leading to inferior signal-to-noise ratios or longer measurement times. Here we demonstrate broadband shot-to-shot detection in transient absorption spectroscopy with a 100-kHz femtosecond laser system. This is made possible using a home-built high-speed chopper with external laser synchronization and a fast CCD line camera. Shot-to-shot detection can reduce the data acquisition time by two orders of magnitude compared to few-kHz lasers while keeping the same signal-to-noise ratio.
KW  - cameras
KW  - CCD
KW  - charge-coupled device
KW  - modulators
KW  - time-resolved spectroscopy
KW  - ultrafast spectroscopy
KW  - ultrafast measurements
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-112853
ER  - 
TY  - JOUR
A1  - Malý, Pavel
A1  - Brixner, Tobias
T1  - Fluorescence‐Detected Pump–Probe Spectroscopy
JF  - Angewandte Chemie International Edition
N2  - 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.
KW  - femtochemistry
KW  - FL spectroscopy
KW  - time-resolved spectroscopy
KW  - transient absorption
Y1  - 2021
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-244811
VL  - 60
IS  - 34
SP  - 18867
EP  - 18875
ER  -