Open AccessThree-dimensional frequency- and phase-multiplexed magneto-optical microscopy
Author(s) -
Mahdi Mehrnia,
Jeremy Trimble,
Jesse Berezovsky
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.033942
Subject(s) - optics , physics , magneto optic kerr effect , kerr effect , phase (matter) , vortex , magnetic force microscope , multiplexing , magnetic field , magnetization , telecommunications , computer science , nonlinear system , quantum mechanics , thermodynamics
We describe a new approach to scanning magneto-optical Kerr effect (MOKE) microscopy in which two opto-mechanical choppers modulate the spatial profile of a probe laser beam to separately encode all three magnetization components at different frequencies and phases in one signal. We demonstrate this multiplexed technique in two representative regimes: the equilibrium and non-equilibrium response of a magnetic vortex to a changing magnetic field. We observe the translation of the vortex state in equilibrium and the spiraling gyrotropic trajectory of the vortex position out of equilibrium. We compare the results to a traditional MOKE measurement and to micromagnetic simulations. We find that the multiplexed method presented here provides better agreement with simulation than previous methods and equal or better signal-to-noise ratio.