Femtosecond intrapulse evolution of the magneto-optic Kerr effect in magnetoplasmonic crystals

TL;DR

This paper investigates ultrafast changes in the magneto-optic Kerr effect within femtosecond pulses reflected from magnetoplasmonic crystals, revealing dynamic effects linked to surface plasmon polaritons and magnetization-dependent dispersion.

Contribution

It demonstrates the first observation of ultrafast, non-trivial evolution of the magneto-optic Kerr effect in magnetoplasmonic structures within femtosecond timescales.

Findings

Observed opposite time derivative signs for different resonance slopes.

Linked the effect to magnetization-dependent SPP dispersion.

Revealed dynamic magneto-optical behavior in femtosecond regime.

Abstract

In magnetoplasmonics, it is possible to tailor the magneto-optical properties of nanostructures by exciting surface plasmon polaritons (SPPs). Thus far, magnetoplasmonic effects have been considered static. Here, we describe ultrafast manifestations of magnetoplasmonics by observing the non-trivial evolution of the transverse magneto-optic Kerr effect within 45-fs pulses reflected from an iron-based magnetoplasmonic crystal. The effect occurs for resonant SPP excitations, displays opposite time derivative signs for different slopes of the resonance, and is explained with the magnetization-dependent dispersion relation of SPPs.