Three-dimensional laser printing of macro-scale glass objects at a micro-scale resolution

Femtosecond laser-induced chemical etching (FLICE) has proved itself a powerful approach when attempting to fabricate three-dimensional (3D) microstructures in glass, whereas maintaining a high spatial resolution in fabricating samples of great heights/thicknesses is challenging due to the diffraction nature of light waves. Here, we demonstrate the fabrication of macro-scale 3D glass objects of large heights up to ∼3.8 cm with a well-balanced lateral and longitudinal resolution of ∼20 μm using the FLICE. Moreover, a freeform hand printed with embedded blood vessel system has been produced. The remarkable accomplishments are achieved by revealing an unexplored regime in the interaction of ultrafast laser pulses with fused silica, which gives rise to depth-insensitive focusing of the laser pulses and polarization-independent selective etching inside fused silica. We examine the difference in the plasma dynamics between interactions of picosecond and femtosecond laser pulses with fused silica glass.