Rapid scan white light two-dimensional electronic spectroscopy with 100 kHz shot-to-shot detection

Area of Science:

• Spectroscopy
• Physical Chemistry
• Ultrafast Dynamics

Background:

• Two-dimensional electronic spectroscopy (2DES) provides insights into molecular dynamics.
• Conventional 2DES methods can be limited by repetition rates and data acquisition times.

Purpose of the Study:

• To develop a novel 2DES approach combining high repetition rates with simplified optical setups.
• To enable faster acquisition of 2DES spectra with improved signal-to-noise ratios.

Main Methods:

• Utilized shot-to-shot detection with a broadband white light continuum input.
• Implemented mutual synchronization between laser repetition rate, acousto-optical deflector, delay stage, and CCD camera.
• Employed rapid scanning of pump optical delay synchronously with the laser repetition rate.

Main Results:

• Achieved measurement of averaged 2DES absorptive spectra with only 1.2 seconds of sample exposure per spectrum.
• Demonstrated a signal-to-noise ratio of 6.8 for optical densities down to 0.05 at 100 kHz repetition rate.
• Showcased a repetition-rate scalable scheme limited only by CCD line rate and stage velocity.

Conclusions:

• The developed 2DES approach offers a viable, scalable alternative to acousto-optic pulse shaping.
• This method provides comparable throughput and sensitivity while minimizing sample exposure.
• The technique shows promise for applications in micro-spectroscopy and rapid dynamic studies.