Effect of dipolar and quadrupolar contribution in first hyperpolarizability of dimethylaniline

The polarization resolved analysis of harmonic generation has been performed on 2,5-Dimethylaniline (DMA) dissolved in Tetrahydrofuran (THF). The internal reference method of Hyper Rayleigh Scattering technique yields the first hyperpolarizability of DMA to be 0.84 × 10−30 esu at 514 nm wavelength from an Ar-ion Laser. The Second Harmonic (SH) signal has also been measured, with respect to the incident polarization angle of the laser beam, to verify the contribution of electric dipole and quadrupole moments in the first hyperpolarizability of DMA. It is found that the electric dipole contributes the most (>90 %) to the hyperpolarizability.