Spin Wave Diffraction and Perfect Imaging of a Grating

TL;DR

This paper investigates how Damon-Eshbach spin waves diffract through a micro-structured grating, revealing unique imaging effects that surpass the wavelength scale due to anisotropic dispersion, with potential implications for magnonic devices.

Contribution

It demonstrates the diffraction and imaging of spin waves through a microfabricated grating, highlighting the role of anisotropic dispersion in achieving sub-wavelength imaging.

Findings

Observed diffraction patterns with spin-wave replications.

Finer-than-wavelength imaging achieved due to anisotropic dispersion.

Confirmed the potential for high-resolution magnonic imaging.

Abstract

We study the diffraction of Damon-Eshbach-type spin waves incident on a one-dimensional grating realized by micro slits in a thin permalloy film. By means of time-resolved scanning Kerr microscopy we observe unique diffraction patterns behind the grating which exhibit replications of the spin-wave field at the slits. We show that these spin-wave images, with details finer than the wavelength of the incident Damon-Eshbach spin wavelength, arise from the strongly anisotropic spin wave dispersion.