A Perspective on Understanding Transient Stimulated Raman Scattering Spectroscopy with Ramsey Interferometry

Transient stimulated Raman scattering (T-SRS), as an emerging time-domain coherent Raman scattering (TD-CRS) technique, possesses unique natural line-width-limit spectral resolution and sub-mM sensitivity, and offers a powerful spectral platform for chemical identification and imaging of biomarkers in biological tissues. However, readers may face difficulties in understanding clear physical pictures of manipulating quantum states of biomolecules by deriving wave packet interference. Here, we reinterpreted T-SRS as Ramsey interferometry driven by two femtosecond half-π operations of the superposition of biomolecules at room-temperature, an analogue to second-scale Ramsey interference of cold atoms at a temperature of ∼1 μK. This perspective contrasts the features of coherent quantum control of Ramsey interference performed in cold atomic and macroscopic biological systems. Both the theoretical reasoning and numeric simulations of quantum evolution are discussed step by step. The interdisciplinary knowledge will foster the advancement of coherent Raman spectroscopy and precision measurements in chemistry and broad biomedical applications.