Wideband detection of transient solid-state dynamics using ultrafast fiber lasers and asynchronous optical sampling

Area of Science:

• Condensed Matter Physics
• Materials Science
• Spectroscopy

Background:

• Optical time-domain spectroscopy is crucial for investigating ultrafast phenomena.
• Understanding thermal transport and spin dynamics in magnetic thin films requires high temporal resolution.
• Bridging fast and slow dynamics is essential for characterizing dissipation and decoherence.

Purpose of the Study:

• To demonstrate an ultrafast dual-fiber-laser system for optical time-domain spectroscopy.
• To utilize the system's broad temporal dynamic range for quantitative studies.
• To detect coherent spin and lattice excitations in magnetic thin films.

Main Methods:

• Employing an ultrafast dual-fiber-laser system with kilohertz scanning rates.
• Utilizing different wavelengths for pump and probe beams.
• Performing optical time-domain spectroscopy across femtosecond to nanosecond timescales.

Main Results:

• Achieved femtosecond to nanosecond time resolution using the developed laser system.
• Enabled quantitative studies of thermal transport in epitaxial magnetic thin films.
• Successfully detected coherent spin and lattice excitations.

Conclusions:

• The ultrafast laser system offers an unprecedented temporal dynamic range.
• The system effectively connects fast and slow timescales for observing dissipation and decoherence.
• This approach provides a powerful tool for investigating complex dynamics in magnetic materials.