Nonlinear optical properties of lead nanocrystals embedding glass induced by thermal treatment and femtosecond laser irradiation

► Lead nanocrystals were precipitated inside borosilicate glass by thermal stimulation and femtosecond laser irradiation. ► Thermal treatment can precipitate lead nanocrystals inside whole glass. ► Femtosecond laser irradiation can fabricate lead nanocrystals within selective area of glass. ► The fabricated nanocrystals-glass composite exhibits large third-order optical nonlinearity and ultrafast response time. ► It is suitable for fabrication of ultrafast optical switches.