NONLINEAR-OPTICAL PROPERTIES OF LEAD-BISMUTH-GALLIUM GLASSES

Low-temperature optical properties of PbO-Bi2O3-Ga2O3 glasses were inv estigated for the first time. Nonlinear optical methods, including pho toinduced second harmonic generation (SHG) and piezooptics, were used as the main tools in our investigations. A ruby laser beam (lambda = 6 94 nm) was applied as a source of photoinduced changes. A temperature split of the SHG signal for wavelength lambda = 1.06 mu m was observed , depending on light polarization. Dielectric and dilatometry measurem ents were performed to investigate contributions of spontaneous polari zation and deformation, respectively. We have observed the appearance of maxima in the corresponding optical susceptibilities between 40 and 60 K.