title: Role of magnetic circular dichroism in all-optical magnetic recording.
abstract: Using magneto-optical microscopy in combination with ellipsometry measurements, we show that all-optical switching with polarized femtosecond laser pulses in ferrimagnetic GdFeCo is subjected to a threshold fluence absorbed in the magnetic layer, independent of either the excitation wavelength or the polarization of the laser pulse. Furthermore, we present a quantitative explanation of the intensity window in which all-optical helicity-dependent switching (AO-HDS) occurs, based on magnetic circular dichroism. This explanation is consistent with all the experimental findings on AO-HDS so far, varying from single- to multiple-shot experiments. The presented results give a solid understanding of the origin of AO-HDS, and give novel insights into the physics of ultrafast, laser controlled magnetism.
authors.affiliation: Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, Nijmegen, The Netherlands. s.khorsand@science.ru.nl
authors.forename: A R
authors.initials: AR
authors.lastname: Khorsand
authors.forename: M
authors.initials: M
authors.lastname: Savoini
authors.forename: A
authors.initials: A
authors.lastname: Kirilyuk
authors.forename: A V
authors.initials: AV
authors.lastname: Kimel
authors.forename: A
authors.initials: A
authors.lastname: Tsukamoto
authors.forename: A
authors.initials: A
authors.lastname: Itoh
authors.forename: Th
authors.initials: T
authors.lastname: Rasing