Metal nanocrystals-glass composites, like Au, Ag, or Cu nanocrystals doped silicate glass, can integrate the large third-order optical nonlinearity of metal nanocrystals and excellent thermal and chemical stability of glass matrix. Applications of such nonlinear optical composite are extremely broad such as ultrafast all optical switching, signal processing, and optical data storage. However, most of the available literatures focus on Au, Ag, or Cu nanocrystals doped glass. Other metal nanocrystals doped glass rarely receives concerns.

In December this year, Researchers at State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fines Mechanics, Chinese Academy of Sciences (SIOM, CAS) have fabricated Pb nanocrystals inside a specially designed borosilicate glass by two parallel approaches, heat and photon stimulation.

During their work, Researchers have fabricated Pb nanocrystals-glass composite by two parallel approaches, heat treatment and femtosecond laser irradiation. Heat treatment can precipitate Pb nanocrystals inside whole glass, while femtosecond laser irradiation can space-selectively direct induce Pb nanocrystals inside glass. The precipitated Pb nanocrystals can greatly enhance the linear and nonlinear indices of the glass, while the response time remains in ultrafast range, which is suitable for fabrication ultrafast optical switches. This work was newly published in recent issue of Chemical Physics Letters 516 (2011) 186–191.

FIG Transmission electron microscopyimage, refractive index profile and diffraction pattern of the femtosecond laser induced grating.(Image by SIOM)