coherent Stokes Raman spectroscopy coherent Stokes resonance Raman spectroscopy CHMO:0000660 Spectroscopy where the Raman scattering of monochromatic light by a sample is detected. An anti-Stokes frequency stimulation beam is used and a Stokes frequency beam is observed and the difference between the pump and the Stokes beams coincides with the frequency of an electronic transition within the molecule. multiphoton excitation is used to produce a signal in which the emitted waves are coherent.