title: Femtosecond pump/supercontinuum-probe setup with 20 kHz repetition rate.
abstract: We developed a fast multichannel detection system for pump-probe spectroscopy, capable of detecting single shot super-continuum spectra at the repetition rate (10-50 kHz) of an amplified femtosecond laser system. By tandem pumping the amplifier with three pump lasers we obtain very low noise operation, with less than 0.1% rms intensity fluctuations at the output of the amplifier. We also propose an alternative way of chopping the pump beam. With a synchronized scanning mirror two spots in the sample are illuminated by the train of pump pulses in an alternating fashion, such that when both spots are interrogated by the probe pulse, the duty cycle of the experiment is doubled.
authors.affiliation: Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB, station 6, CH-1015 Lausanne, Switzerland.
authors.forename: Gerald
authors.initials: G
authors.lastname: Auböck
authors.forename: Cristina
authors.initials: C
authors.lastname: Consani
authors.forename: Roberto
authors.initials: R
authors.lastname: Monni
authors.forename: Andrea
authors.initials: A
authors.lastname: Cannizzo
authors.forename: Frank
authors.initials: F
authors.lastname: van Mourik
authors.forename: Majed
authors.initials: M
authors.lastname: Chergui