Investigation of third-order nonlinear optical parameters and optical limiting behavior of PbO•Bi2O3•Ga2O3 glasses

The standard melt-quenching technique was used to synthesize heavy metal-based PbO center dot Bi2O3 center dot Ga2O3 glasses. The physical properties such as density and molar volume were calculated, and it is found that these parameters decrease with an increase in the Bi2O3 content of the studied samples. The optical transmittance spectra were recorded in 300-3300 nm wavelength range for all the glasses. The presence of a sharp cutoff and a wide transmission (from 0.43 to 2.5 mu m) shows the suitability of these glasses for the IR transmission window. From the absorption analysis cutoff wavelength, the optical bandgap and Urbach's energy were estimated. The bandgap values of these glasses range from 2.51 to 2.59 eV. Third-order nonlinear optical properties of PbO center dot Bi2O3 center dot Ga2O3 glasses were studied using the Z-scan technique. With increasing Bi2O3 concentration in the studied glasses, third-order nonlinear refractive index and third-order nonlinear susceptibility were found to increase while bandgap decreased, which might be related to an increase in the quantity of non-bridging oxygens. IR studies indicate that these glasses are composed of [BiO3], [BiO6], [GaO4], [PbO3] and [PbO4] fundamental structural units. From optical limiting studies, the dynamic range and limiting threshold of the glasses were calculated. Good optical limiting responses and significant values of dynamic range for all the glasses indicate that the investigated glasses can be explored for optical limiting applications.