Sub-nanosecond time-resolved near-field scanning magneto-optical microscope

• Published in: Review of scientific instruments Vol. 86; no. 2; p. 023703
• Main Authors: Rudge, J, Xu, H, Kolthammer, J, Hong, Y K, Choi, B C
• Format: Journal Article
• Language: English
• Published: United States 01.02.2015
• ISSN: 1089-7623
• DOI: 10.1063/1.4907712

We report on the development of a new magnetic microscope, time-resolved near-field scanning magneto-optical microscope, which combines a near-field scanning optical microscope and magneto-optical contrast. By taking advantage of the high temporal resolution of time-resolved Kerr microscope and the sub-wavelength spatial resolution of a near-field microscope, we achieved a temporal resolution of ∼50 ps and a spatial resolution of <100 nm. In order to demonstrate the spatiotemporal magnetic imaging capability of this microscope, the magnetic field pulse induced gyrotropic vortex dynamics occurring in 1 μm diameter, 20 nm thick CoFeB circular disks has been investigated. The microscope provides sub-wavelength resolution magnetic images of the gyrotropic motion of the vortex core at a resonance frequency of ∼240 MHz.