Abstract
By applying the numerically computed energy levels and wave functions of the π electrons of the molecule following the Su-Schrieffer-Heeger model, we calculated the second-order quadrupole nonlinear susceptibility for the medium and the calculated value is 1.7× /V for the fundamental wave λ=1.064 μm. For the fundamental wave λ=1.064 μm, the second-order susceptibility caused by the second-order nonlinear quadrupole polarization has the magnitude 1.1× m/V (i.e., 2.5× esu). This result is in excellent agreement with the recent experimental measurements. In addition, we also calculated the quadrupole-induced reflection and transmission second-order harmonic generation by further considering the effect of finite film thickness.
- Received 11 June 1993
DOI:https://doi.org/10.1103/PhysRevB.48.17562
©1993 American Physical Society