Fabrication of microlenses in Ag-doped glasses by a focused continuous wave laser beam

Abstract

A technique for the fabrication of small (2–10 μm in diameter) microlenses on the surface of glass with embedded silver nanoclusters in a subsurface diffusion layer is demonstrated. The dependence of the microlens size on the exposure time and the laser power of a focused continuous wave (cw) laser beam is discussed. It is shown that the optical transmission of the lenses increases with increasing laser power used for the exposure. The temperature distribution in the glass around the focal spot is calculated taking into account the temperature dependence of heat conductivity, shape of the beam, and decrease of absorption coefficient with depth through the diffusion layer containing Ag clusters. The measured microlens sizes are in good agreement with the calculations.