Electron-phonon coupling via non-markovian process in Nd: YAG

The 4f electronic transition accompanied by electron-phonon interaction was studied through the Brownian oscillator model in Nd: YAG. The expression of electron-phonon coupling was derived, the excitation spectroscopies of different electron-phonon coupling constants were calculated and the results indicated the absorption peak of phonon in two sides of electronic peak is produced by electron-phonon coupling. The stronger electron-phonon coupling, the more phonon peaks. Through excitation spectroscopy simulation, the electron-phonon coupling constant and phonon frequency were obtained. From these data, the theoretical time resolved coherent spectroscopy was calculated and is good agreement with experiment result. It also indicated that the electron-phonon coupling in rare earth ion's 4f electronic transition is weak because of the smaller constant of electron-phonon coupling compared with that of semiconductor.