Conventional narrowband femtosecond stimulated Raman spectroscopy (SRS) implementations often rely on complex optical parametric systems or static narrowband filters, limiting vibrational mode tunability and operational simplicity. Here, we present a chirped-gated SRS (CG-SRS) technique that enables mode-selective control across a broadband vibrational spectrum. By applying a controlled chirp to the broadband probe pulse, CG-SRS establishes a time–frequency mapping mechanism that allows distinct vibrational modes to be selectively addressed and enhanced at different probe delays under single-wavelength excitation. This method enables dynamic enhancement or suppression of individual Raman modes without filter-based tuning. Using ethanol as a model system, we demonstrate selective enhancement of individual vibrational contributions within the C–H stretching region and further achieve dynamic switching from the 980 to the 2900 cm−1 via time-delay control. Additional validation is carried out using liquid water and diamond. CG-SRS provides a powerful tool for mode-selective vibrational control and offers a promising reference for selective excitation in chemical reactions and biomedical imaging.
Gao et al. (Mon,) studied this question.