Role of SiO₂ in tailoring stability and nonlinear optical behaviour of gold nanoparticles in glass

In the present work, a new approach is introduced to mitigate the loss of gold nanoparticles while preparing the glass through the traditional melt-quench technique. The role of refractory material i.e. SiO₂ in loss reduction is studied by comparing the results obtained for bismuth borate (40Bi₂O₃:60B₂O₃) and borosilicate (40Bi₂O₃:40B₂O₃:20SiO₂) glasses containing gold nanoparticles of different sizes (10 nm, 40 nm and 100 nm). The particle density and thermal stability obtained from FESEM and DTA, respectively, increase considerably with the presence of SiO₂ as one of the components of glass composition. The nonlinear optical behaviour of both systems in non-resonant regions has been obtained using the Z-scan technique. In addition, the suitability of the prepared glasses for optical limiting and switching applications has been analysed.