Ultrafast Laser Processing of Glass Down to the Nano-Scale

Summary

Ultrafast lasers can induce strong absorption in materials and even in transparent materials, due to nonlinear multiphoton absorption. By using this phenomenon, surface microstructuring and dicing of glass are successfully demonstrated. When the ultrafast laser is focused inside a transparent material with adequate pulse energies, absorption can be confined to a region near the focus point allowing for internal processing of the transparent material such as three-dimensional (3D) optical waveguide writing and fabrication of micro-optical components and microchannels buried inside the glass. Another important feature of ultrafast lasers is the suppression of heat diffusion to the surroundings of the processed area, which makes nanoscale fabrication possible. In addition, nonlinear multiphoton absorption can further improve the spatial resolution beyond that of the laser. In this chapter, the features of ultrafast laser processing are first described and clarified. Then, some relevant topics of glass processing including nanoscale fabrication are reviewed.