Stimulated Raman spectroscopy

Stimulated Raman spectroscopy, also referred to as stimulated Raman scattering (SRS), is a form of spectroscopy employed in physics, chemistry, biology, and other fields. The basic mechanism resembles that of spontaneous Raman spectroscopy: a pump photon, of the angular frequency ω p {\displaystyle \omega _{p}} , which is scattered by a molecule has some small probability of inducing some vibrational (or rotational) transition, as opposed to inducing a simple Rayleigh transition.

Source: Wikipedia — Stimulated Raman spectroscopy (CC BY-SA 4.0)