Fabrication and third-order optical nonlinearities of Na2O-B2O3-SiO2 glasses containing metallic Bi, Bi2O3 and Bi2S3 crystals

► The glasses containing the various kinds of Bi crystals are fabricated. ► The microstructures are studied by XRD, TEM, and XPS. ► Z-scan technique is used to measure the third-order optical nonlinearities. ► An excellent third-order nonlinear optical absorption.