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Terahertz-Magnetic-Field Induced Ultrafast Faraday Rotation of Molecular Liquids
Vasileios Balos1, Genaro Bierhance1, Martin Wolf1
1Fritz Haber Institute of the Max Planck Society, Faradayweg 4-6, 14195 Berlin, Germany.
Physical Review Letters
|March 24, 2020
Summary
Scientists achieved ultrafast Faraday rotation in molecular liquids using intense terahertz magnetic fields. This breakthrough enables subpicosecond polarization control of light, advancing optical device technology.
Area of Science:
- Optics and Photonics
- Physical Chemistry
- Electromagnetism
Background:
- Faraday rotation, the magnetic field-induced rotation of light polarization, is crucial for optical devices.
- Achieving ultrafast Faraday rotation on a subpicosecond timescale is a key research objective.
- Existing methods often lack the speed required for ultrafast optical applications.
Purpose of the Study:
- To demonstrate ultrafast Faraday rotation on a subpicosecond timescale.
- To investigate the effect of intense, ultrashort magnetic fields on light polarization in molecular liquids.
- To explore the underlying mechanism of ultrafast polarization rotation.
Main Methods:
- Application of an intense single-cycle terahertz (THz) magnetic field to simple molecular liquids.
- Measurement of the rotation of the plane of polarization of an optical pulse traversing the liquids.
- Analysis of the dependence of Faraday rotation on THz magnetic field strength and molecular properties.
Main Results:
- Successful demonstration of subpicosecond timescale Faraday rotation in molecular liquids.
- Observed Faraday rotation scales linearly with the THz magnetic field intensity.
- Rotation magnitude is quadratically dependent on the molecular polarizability of the liquid.
Conclusions:
- Intense THz magnetic fields can induce ultrafast Faraday rotation in molecular media.
- The effect is attributed to the deflection of optically induced electric polarization by the THz magnetic field.
- This provides a novel pathway for controlling light polarization at ultrafast timescales.
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