1-and 2-photon-absorption properties of two organic molecules based on the Lorentz quantum impedance oscillator

Based on Bohr-Sommerfeld quantum theory and the single and two-photon absorption selection rule of quantum mechanics, a new quantum impedance Lorentz oscillator model is proposed, which relates the electron transition process to the resonance absorption of the Lorentz oscillator. The natural frequency of the oscillator is unified with the intrinsic frequency of the electron transition. A formula for calculating the parameters of the oscillator, including the damping coefficient, is given in terms of the electron charge and mass, Bohr radius and effective quantum number. Based on the Boltzmann distribution of thermodynamics, an expression of vibrator intensity under the emission and absorption equilibria of light is presented. Based on this model and considering that "electron pair" is one of the molecular chemical bonds, the effective quantum number before and after the electronic transition of TPAT-AN-XF and ASPI is calculated by fitting the linear absorption spectra of TPAT-AN-XF and ASPI, and also the two-photon absorption cross sections of the two organic molecules are numerically simulated. The numerical results agree well with the experiment. The results show that the quantum impedance Lorentz oscillator can better describe the absorption properties of TPAT-An-XF and ASPI.