Nonlinear optical properties of lead-bismuth-gallium glasses

Low-temperature optical properties of PbO-Bi2O3-Ga2O3 glasses were investigated for the first time. Nonlinear optical methods, including photoinduced second harmonic generation (SHG) and piezooptics, were used as the main tools in our investigations. A ruby laser beam (lambda = 694 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 measurements were performed to investigate contributions of spontaneous polarization and deformation, respectively. We have observed the appearance of maxima in the corresponding optical susceptibilities between 40 and 60 K.