2024/08/06 by Stephen Revesz, Revesz, Stephen, Rustam Gatamov +5
Biochemistry, Genetics and Molecular Biology · Chemistry · Medicine · #Applied Physics (physics.app-ph) #FOS: Physical sciences #Optical Imaging and Spectroscopy Techniques #Optics (physics.optics) #Spectroscopy Techniques in Biomedical and Chemical Research #Spectroscopy and Laser Applications
paper · pdf · doi:10.48550/arxiv.2408.03412
openalex publication_date 2024/08/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Optical two-dimensional coherent spectroscopy (2DCS) is a powerful ultrafast spectroscopic technique that can greatly benefit from the unique features of a femtosecond laser operating at a kHz repetition rate. However, isolating specific nonlinear signal in the collinear geometry, especially with a kHz laser, presents challenges. We present an experimental implementation of optical 2DCS in a collinear geometry using a femtosecond laser operating at a 5 KHz repetition rate. The desired nonlinear signal is selectively extracted in the frequency domain by lock-in detection. Both pump-probe and optical 2DCS experiments were conducted on a rubidium vapor. The signal-to-noise ratio of pump-probe and 2DCS spectra was characterised under various experimental parameters. The study highlights the importance of the lock-in reference frequency in overcoming the limitations imposed by low repetition rates, thereby paving the way for the application of collinear optical 2DCS in material systems requiring kHz femtosecond lasers.