Set-up for broadband Fourier-transform multidimensional electronic spectroscopy.

Area of Science:

• Ultrafast spectroscopy
• Nonlinear optics
• Physical chemistry

Background:

• 2D Fourier transform (2DFT) spectroscopy is a powerful technique for analyzing molecular dynamics.
• Achieving stable, ultra-broadband light sources is crucial for high-resolution 2DFT measurements.
• Characterizing ultrafast vibrational coherences provides insights into molecular structure and function.

Purpose of the Study:

• To develop a compact and passively phase-stabilized ultra-broadband 2D Fourier transform setup.
• To generate sub-10-femtosecond pulses for high-resolution spectroscopic analysis.
• To investigate the nonlinear optical response and vibrational dynamics of Rhodamine 101.

Main Methods:

• Utilized an amplified Ti:Al2O3 laser to pump an argon-filled hollow core fiber, generating an ultra-broadband light source (420-900 nm).
• Employed a deformable mirror-based pulse shaper to achieve sub-10-femtosecond pulse durations.
• Performed 2D Fourier transform spectroscopy on Rhodamine 101 to probe its nonlinear response.

Main Results:

• Successfully generated an ultra-broadband light source spanning 420-900 nm with sub-10-fs pulses.
• Resolved vibrational coherences with a 150 fs period in the ground state of Rhodamine 101.
• Demonstrated the capability of the compact setup for detailed molecular dynamics studies.

Conclusions:

• The developed compact 2D Fourier transform setup offers a stable and efficient platform for ultrafast spectroscopy.
• The system enables high-resolution probing of molecular vibrational coherences.
• This work advances the tools available for studying complex molecular systems.