Principles Of Nonlinear Optical Spectroscopy A Practical Approach Or Mukamel For Dummies Fixed [new] -
). In nonlinear optics, since we use the density matrix, we have operators acting from both the left and the right (
represent absorbing a photon or an interaction with the field. Arrows pointing out represent emission or the "signal." ). In nonlinear optics
Nonlinear spectroscopy is simply the art of asking a molecule a question, waiting for it to start answering, interrupting it with another question, and then listening to the confused (but informative) response. since we use the density matrix