The frequency difference between the pump and Stokes beams is adjusted to match a molecular vibration. When that match occurs, the stimulated Raman scattering signal increases, allowing the resulting image to emphasize a chemically defined feature rather than general optical structure. Changing the targeted vibrational frequency can therefore distinguish molecular components such as lipids, proteins, or metabolites.
SRS imaging depends on synchronized pump and Stokes laser beams working together. Their interaction produces a stronger Raman signal when their frequency difference corresponds to a molecular vibration. This synchronized, frequency-dependent process supplies the contrast used to map chemical composition, allowing the instrument to generate images based on molecular features rather than fluorescent labels.
Label-free contrast allows living cells and tissues to be examined without adding fluorescent tags to the structures of interest. In neuroscience, this can preserve the native chemical context of neural samples and minimize sample disruption. The approach is especially useful when researchers need to observe lipids, proteins, metabolites, or other molecular features directly within nervous-system tissue.
A typical workflow begins by selecting the molecular vibration associated with the feature of interest, then tuning the pump and Stokes beams so their frequency difference matches that vibration. The synchronized beams are directed at living cells or tissue, and the increased scattering signal is converted into an image that maps the selected chemical component.
In neuroscience, SRS imaging can examine lipid-rich myelin as well as proteins, metabolites, and other molecular features in cells and tissues. This combination links neural structure with chemical composition, helping investigators study how tissue organization and molecular content relate to normal nervous-system biology or changes associated with disease.
The technique supports investigations of brain metabolism, demyelinating disease, and tumor biology, while also enabling assessment of treatment responses. Its chemical imaging capability can reveal molecular and structural features in living neural samples with minimal disruption. These applications help connect observed tissue changes with altered lipids, proteins, metabolites, or other compositional features.