All-optical switching on a nanometer scale

https://phys.org/news/2022-06-all-optical-nanometer-scale.html 

"excited transient magnetic grating (TMG) with periodicity of ΛTMG = 87 nm in ferrimagnetic GdFe alloy... spatial evolution magnetization grating probed by diffracting time-delayed, third XUV pulse tuned Gd N-edge at wavelength 8.3 nm (150 eV)... linear magnetization response to excitation and no AOS, sinusoidal TMG induced and second diffraction order suppressed... intensity ratio between the second and first order (R21) as a fingerprint observable for AOS in diffraction experiments"