title: Generation of infrared supercontinuum radiation: spatial mode dispersion and higher-order mode propagation in ZBLAN step-index fibers.
abstract: Using femtosecond upconversion we investigate the time and wavelength structure of infrared supercontinuum generation. It is shown that radiation is scattered into higher order spatial modes (HOMs) when generating a supercontinuum using fibers that are not single-moded, such as a step-index ZBLAN fiber. As a consequence of intermodal scattering and the difference in group velocity for the modes, the supercontinuum splits up spatially and temporally. Experimental results indicate that a significant part of the radiation propagates in HOMs. Conventional simulations of super-continuum generation do not include scattering into HOMs, and including this provides an extra degree of freedom for tailoring supercontinuum sources.
authors.affiliation: Department of Chemistry, Aarhus University, DK-8000 Aarhus C, Denmark.
authors.forename: Jacob
authors.initials: J
authors.lastname: Ramsay
authors.forename: Sune
authors.initials: S
authors.lastname: Dupont
authors.forename: Mikkel
authors.initials: M
authors.lastname: Johansen
authors.forename: Lars
authors.initials: L
authors.lastname: Rishøj
authors.forename: Karsten
authors.initials: K
authors.lastname: Rottwitt
authors.forename: Peter Morten
authors.initials: PM
authors.lastname: Moselund
authors.forename: Søren Rud
authors.initials: SR
authors.lastname: Keiding
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007259:Infrared Rays; D008029:Lighting / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*