Raman scattering cross-section and non-linear optical response of lead borate glasses

Abstract

Lead borate glasses in the system xPbO · (10 - x)B2O3(5 ⩽ x ⩽ 9) have been studied by Raman scattering and Z-scan non-linear optical measurements. It is found that both Raman scattering cross-section and non-linear refractive index, n2, of glasses increase significantly with increasing lead oxide content. The increase in Raman cross-section is dominated by an increase in the low-frequency Raman scattering. The results indicate that both electronic and nuclear responses contribute to the observed optical non-linearity which is further enhanced by two-photon resonance effects for glasses with x ⩾ 80 mol%. The nuclear response is attributed to low-frequency vibrational modes and the electronic response to highly polarizable lead cations in the glass matrix.