Coherent Stokes Raman spectroscopy (CSRS pronounced as "scissors") is a form of spectroscopy used primarily in chemistry, physics and related fields. It is closely related to Raman spectroscopy and lasing processes. It is very similar to Raman spectroscopy, but involves a lasing process that dramatically improves the signal.
It is very similar to the more common CARS except it uses an anti-Stokes frequency stimulation beam and a Stokes frequency beam is observed (the opposite of CARS). This is disadvantageous because anti-stokes processes must start in a less populated excited state.