Stimulated Raman Scattering: From Bulk to Nano

Abstract

Stimulated Raman scattering (SRS) describes a family of techniques first discovered and developed in the 1960s. Whereas the nascent history of the technique is parallel to that of laser light sources, recent advances have spurred a resurgence in its use and development that has spanned across scientific fields and spatial scales. SRS is a nonlinear technique that probes the same vibrational modes of molecules that are seen in spontaneous Raman scattering. While spontaneous Raman scattering is an incoherent technique, SRS is a coherent process, and this fact provides several advantages over conventional Raman techniques, among which are much stronger signals and the ability to time-resolve the vibrational motions. Technological improvements in pulse generation and detection strategies have allowed SRS to probe increasingly smaller volumes and shorter time scales. This has enabled SRS research to move from its original domain, of probing bulk media, to imaging biological tissues and single cells at the micro scale, and, ultimately, to characterizing samples with subdiffraction resolution at the nanoscale. In this Review, we give an overview of the history of the technique, outline its basic properties, and present historical and current uses at multiple length scales to underline the utility of SRS to the molecular sciences.

Raman spectroscopy: techniques and applications in the life sciences

“…The involvement of the virtual state is again apparent in this representation. Furthermore, the Feynman diagrams reveal the dependence of spontaneous Raman scattering on an interaction with the vacuum field [32]. This interaction has an arbitrary phase, making the resulting scattered radiation incoherent [33].…”

“…These processes are driven by coherent interactions with pump and Stokes (or probe) beams [32]. These coherent interactions greatly increase the measurable signal.…”

Electronic Preresonance Stimulated Raman Scattering Microscopy

“…27,28 By virtue of these advantages, SRS imaging, mostly in the label-free form, has made a major impact with exciting applications in biological and medical photonics. 28,33−43 Such a label-free strategy is appealing and powerful as it introduces zero physical and chemical perturbation to biological systems. Going beyond the label-free concept, the coupling of SRS microscopy with small and bio-orthogonal vibrational tags, such as alkynes (i.e., carbon–carbon triple bond), has been recently demonstrated for the detection of small biomolecules in the cell-silent Raman spectral window.…”

Nonlinear spectroscopy of plasmonic nanoparticles

“…Stimulated Raman scattering (SRS) is a pump-probe technique in which energy from a pump beam is transferred to a probe beam via a vibrational state [107,108]. It is very similar to CARS with the difference that in CARS the detected nonlinear polarization oscillates at a new frequency, while in SRS the nonlinear polarization oscillates at the optical probe frequency.…”