Nonlinear saturable absorption of the sodium borosilicate glass containing Bi2S3 nanocrystals using Z-scan technique

The sodium borosilicate glass containing Bi2S3 nanocrystals is prepared by employing both sol–gel and atmosphere control methods. The third-order nonlinear optical absorption of the glass is investigated in detail using the open-aperture Z-scan technique at the wavelength of 770 nm with a pulse width of 200 fs. The results show that the transformation from saturable absorption to reverse saturable absorption in the glass is observed with the increase of the input light intensity of the laser used. The mechanism of the third-order nonlinear optical absorption is discussed preliminarily in the glass. Meanwhile, XRD, XPS, TEM, (S)TEM, EDAX, HRTEM, and SAED are used to characterize the microstructures of the glass.

► A facile method to realize the preparation of the sodium borosilicate glass containing Bi2S3 nanocrystals.
► The microstructures of the glass are investigated in detail by means of XRD, XPS, and TEM analysis.
► The third-order optical nonlinear absorption of the glass is measured using the open-aperture Z-scan technique.
► The transformation from saturable absorption to reverse saturable absorption is observed in the glass, which depends drastically on the input intensity of the femto-second laser used.