Strong versus Weak Excitation in Frequency Mixing and Harmonic Generation by Two-Level Systems |
| R. Parzyński, T. Kopyciuk
Faculty of Physics, A. Mickiewicz University, Uniwersytetu Poznańskiego 2, 61-614 Poznań, Poland |
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| In the limits of weak and strong excitation, we solve analytically the Riccati-type differential equation for a two-level system in the field of two different lasers and then use these solutions to find easy to handle formulae for the induced electric-dipole moment of the system. We apply these formulae to describe the effects of strong excitation in both the higher harmonics generation and multiphoton frequency mixing, namely the diminishing of the generation of harmonics of a given laser when an additional laser is turned on and the diminishing of the radiation at mixed frequencies with increasing strength of lasers under the condition of multiphoton excitation. |
DOI:10.12693/APhysPolA.140.407 topics: extreme nonlinear optics, frequency conversion |