RESUMO
The optimized conditions for the enhancement of the second harmonic generation in the composites of the orthorhombic δ-BiB3O6:Pr(3+) nanoparticles embedded in polyvinyl alcohol films and deposited on the AgGaGe2Se6, AgGaGe2.7Si0.3Se8 (90 mol.% AgGaGe3Se8 - 10 mol.% AgGaSi3Se8), and AgGaGe3Se8:Cu substrates were established. The highest second-order susceptibility was achieved during the Ag-Ga-Ge-Se crystalline substrates photo-illumination by nanosecond laser pulses of about 2900 nm wavelength. The effect was found to be completely reversible after the interruption of the photo-inducing stimulation. Complementary studies of Atomic Force Microscopy, AFM, X-ray Diffraction, XRD, and Fourier-Transform Infrared Spectroscopy, and DFT simulations of spectral dependences of the corresponding second-order nonlinear optical susceptibilities, were performed.
