We report the terahertz radiation in the polar and ferrimagnetic insulating oxide LiFe5O8 upon irradiation of a femtosecond laser pulse at room temperature. By the resonant optical excitation of an originally spin-forbidden d-d transition in Fe3+ ions, we observed the emission of terahertz waves, which is attributable to the magnetic-dipole radiation originating from the light-induced subpicosecond magnetization modulation. By mapping out the emission of the terahertz waves, we successfully visualized the vector images of in-plane magnetic domains in magnetic fields. The terahertz-radiation imaging presented here is useful as a new tool to observe ferromagnetic or ferrimagnetic domains.
- magnetic domains
- magnetization modulation
- terahertz radiation imaging
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering