title: Efficient spectral broadening in the 100-W average power regime using gas-filled kagome HC-PCF and pulse compression.
abstract: We present nonlinear pulse compression of a high-power SESAM-modelocked thin-disk laser (TDL) using an Ar-filled hypocycloid-core kagome hollow-core photonic crystal fiber (HC-PCF). The output of the modelocked Yb:YAG TDL with 127 W average power, a pulse repetition rate of 7 MHz, and a pulse duration of 740 fs was spectrally broadened 16-fold while propagating in a kagome HC-PCF containing 13 bar of static argon gas. Subsequent compression tests performed using 8.4% of the full available power resulted in a pulse duration as short as 88 fs using the spectrally broadened output from the fiber. Compressing the full transmitted power through the fiber (118 W) could lead to a compressed output of >100  W of average power and >100  MW of peak power with an average power compression efficiency of 88%. This simple laser system with only one ultrafast laser oscillator and a simple single-pass fiber pulse compressor, generating both high peak power >100  MW and sub-100-fs pulses at megahertz repetition rate, is very interesting for many applications such as high harmonic generation and attosecond science with improved signal-to-noise performance.
authors.forename: Florian
authors.initials: F
authors.lastname: Emaury
authors.forename: Clara J
authors.initials: CJ
authors.lastname: Saraceno
authors.forename: Benoit
authors.initials: B
authors.lastname: Debord
authors.forename: Debashri
authors.initials: D
authors.lastname: Ghosh
authors.forename: Andreas
authors.initials: A
authors.lastname: Diebold
authors.forename: Frederic
authors.initials: F
authors.lastname: Gèrôme
authors.forename: Thomas
authors.initials: T
authors.lastname: Südmeyer
authors.forename: Fetah
authors.initials: F
authors.lastname: Benabid
authors.forename: Ursula
authors.initials: U
authors.lastname: Keller