Ultrafast Laser-Induced Phenomena inside Transparent Materials

Abstract

This chapter discusses the phenomena induced by ultrafast laser pulses (ULPs) inside transparent materials such as glasses and photoresists with relevant applications to fabrication of some functional three-dimensional (3D) microdevices by each process. It introduces the hybrid technique of ultrafast laser 3D processing to offer rapid prototyping technologies for the fabrication of 3D multifunctional biochips. The advantages of ULP can be exploited in precision micromachining of various materials, from glasses to polymers, in the range of applications where micrometer and submicrometer feature sizes are required. Both linear and nonlinear absorption processes are possible in ULP interaction with matter. Important parameters in the case of ULP-induced spatial resolution are the laser repetition rate, energy and the numerical aperture of the objectives used to focus the beam inside the materials, and the material properties. Two-Photon Polymerization can tailor the shape and size of the solidified resin volume element that determines the resolution.