title: Multioctave infrared supercontinuum generation in large-core As₂S₃ fibers.
abstract: We report on infrared supercontinuum (SC) generation through laser filamentation and subsequent nonlinear propagation in a step-index As2S3 fiber. The 100 μm core and high-purity As2S3 fiber used exhibit zero-dispersion wavelength around 4.5 μm, a mid-infrared background loss of 0.2  dB/m, and a maximum loss of only 0.55  dB/m at the S-H absorption peak around 4.05 μm. When pumping with ultrashort laser pulses slightly above the S-H absorption band, broadband infrared supercontinua were generated with a 20 dB spectral flatness spanning from 1.5 up to 7 μm. The efficiency and spectral shape of the SC produced by ultrashort pulses in large-core As2S3 fiber are mainly determined by its dispersion, the S-H contaminant absorption, and the mid-infrared nonlinear absorption.
authors.forename: Francis
authors.initials: F
authors.lastname: Théberge
authors.forename: Nicolas
authors.initials: N
authors.lastname: Thiré
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Daigle
authors.forename: Pierre
authors.initials: P
authors.lastname: Mathieu
authors.forename: Bruno E
authors.initials: BE
authors.lastname: Schmidt
authors.forename: Younès
authors.initials: Y
authors.lastname: Messaddeq
authors.forename: Réal
authors.initials: R
authors.lastname: Vallée
authors.forename: François
authors.initials: F
authors.lastname: Légaré