Hi, For someone my question could be very simple but I couldn't find a well explain paper that explain this to me. In a Raman spectrometer the stokes and anti-stokes wavelength will always be grater than the laser wavelength used?. I have this confusion because I saw that Raman spectrometers commonly use an edge filter that is usually a couple o nm grater than the laser wavelength. For example for a 532nm use a 534 or 538nm edge filter to reflect only the stokes and anti-stokes wavelength. If some one can explain this to me I will appreciate it.