Third-order optical nonlinearity of Na₂O–B₂O₃–SiO₂ glass doped with lead nanoparticles prepared by sol–gel method

Highlights: • The Pb nanoparticles embedded in Na₂O–B₂O₃–SiO₂ glass were prepared by sol–gel methods. • The crystal phase and composition of glass were characterized by XRD, EDS and XPS. • The morphology and microstructure were measured by TEM. • The formation mechanism of the glass was investigated. • The third-order optical nonlinearity was investigated by using Z-scan technique. - Abstract: Lead-nanoparticles-doped Na₂O–B₂O₃–SiO₂ (NBS) glass was prepared by sol–gel and atmosphere control methods. The formation mechanism and the microstructure of the specimens were investigated by differential thermal analysis and thermal gravimeter, X-ray diffraction, transmission electron microscopy, selected area electron diffraction, energy dispersive X-ray spectroscopy, and nitrogen adsorption measurements, respectively. The linear and nonlinear optical properties of the glass were analyzed by UV/VIS/NIR spectrophotometry and Z-scan technology. The results showed that the Pb nanoparticles in spherical shape with the average particle size about 18.9 nm belong to cubic crystal system and have good crystallinity and dispersibility in the glass matrix as well as exhibit excellent nonlinear optical properties. The specimen has a high linear optical transmittance, and little absorption peaks appear in the examined wavelength range. The third-order optical nonlinear parameters calculated are γ of 1.67 × 10⁻¹⁶ m²/W, β of 7.02 × 10⁻¹¹ m/W, and χ⁽³⁾ of 2.61 × 10⁻¹⁷ m²/W²