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  - Brixner, Tobias
A1  - Pawłowska, Monika
A1  - Goetz, Sebastian
A1  - Dreher, Christian
A1  - Wurdack, Matthias
A1  - Krauss, Enno
A1  - Razinskas, Gary
A1  - Geisler, Peter
A1  - Hecht, Bert
T1  - Shaping and spatiotemporal characterization of sub-10-fs pulses focused by a high-NA objective
N2  - We describe a setup consisting of a 4 f pulse shaper and a microscope with a high-NA objective lens and discuss the spects most relevant for an undistorted spatiotemporal profile of the focused beam. We demonstrate shaper-assisted pulse compression in focus to a sub-10-fs duration using phase-resolved interferometric spectral modulation (PRISM). We introduce a nanostructure-based method for sub-diffraction spatiotemporal characterization of strongly focused pulses. The distortions caused by optical aberrations and space–time coupling from the shaper can be reduced by careful setup design and alignment to about 10 nm in space and 1 fs in time.
KW  - Interference microscopy
KW  - Scanning microscopy
KW  - Subwavelength structures
KW  - nanostructures
KW  - Pulse shaping
KW  - Ultrafast measurements
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-111120
ER  -