THEORY OF 2ND-HARMONIC GENERATION OF MOLECULAR-SYSTEMS - THE STEADY-STATE CASE

In this paper, a general formalism for treating both steady-state and time-resolved second-harmonic generation for molecular systems is pres ented. Here, only the steady-state case will be reported. The adiabati c approximation is introduced. Four important cases, resonance-resonan ce, resonance-off-resonance, off-resonance-resonance, and off-resonanc e-off-resonance transitions, have been considered. Finally, numerical calculations of rhodamine 6G are performed to demonstrate the applicat ions of theoretical results.