Figure 1.

(a) Three-dimensional patterning/printing with ultra-short laser pulses with stages delivering lateral $xy$ in-plane positioning and an objective lens height control provides depth (z-axis) position of the focal spot inside of on the surface of the sample. (b) Schematics: plasma under-etched profile thorough the holes ablated in Cr mask (20–50 nm thick). SEM image of Cr-mask after etching through ablated holes. Threshold effect of focal intensity distribution tuned to the material modification/ablation level.