Z-scan study of third-order optical nonlinearities in bismuth-based glasses

The third-order optical nonlinearity was measured in bismuth-based glasses by Z-scan technique using femto-second laser pulses. Re(χ(3)) = 4.9 × 10−11 esu at 748 nm was obtained in the glass containing 65.5 mol% of Bi2O3. Although, the wavelength dependence of Re(χ(3)) shows resonant effect significantly, relatively small nonlinear absorption coefficient β = 0.8 cm/GW at 769 nm was estimated. Bismuth-based glass exhibits the largest third-order optical nonlinearity in oxide glasses, indicating they are promising materials used for nonlinear optical devices.