Fig. 1. Percussion drilling on steel foil with different laser pulse durations. (a)~(c) are the processing results of 200 fs, 80 ps, 3.3 ns laser pulse width, respectively^[24]

Fig. 2. Schematic diagram of the experimental optical paths for temporally shaping. (a) Spatial light modulation method based on Fourier optics^[27]; (b) Michelson double pulse generation system^[28]; (c) Temporally shaping device based on the thin-films system^[31]

Fig. 3. Schematic diagram of the experimental optical paths for spatially shaping. (a) Schematic illustration of spatial shaping using spatial light modulator (SLM) ^[32]; (b) Schematic illustration of spatial shaping using slit^[33]; (c) Schematic illustration of generating Bessel beam from Gaussian beam by using axicon^[34]

Fig. 4. Microholes drilling by temporally shaping femtosecond laser. (a) Microholes drilled by unshaped pulse and triple-pulses with different intervals in fused silica^[39]; (b) Microholes drilled from back surface of K9 glass by unshaped pulse (up) and double pulse (down) under dynamic focusing condition^[40]; (c) Experiment setup for generating asymmetrically temporal Airy pulses^[42]; (d) Microholes morphology on fused silica formed by laser irradiation of unshaped pulse (up) and double-pulse (down) followed by chemical etching^[27]; (e) Crater morphology on fused silica formed by laser irradiation of unshaped pulse and decreasing pulse-trains followed by chemical etching^[29]; (f) Microholes morphology on fused silica formed by laser irradiation of single pulse (up) and double pulse (down) Bessel beam followed by chemical etching^[44]

Fig. 5. Microholes drilling by spatially femtosecond laser. (a) Microholes drilled by single pulse Bessel beam in thin glass^[46]; (b) The effect of laser pulse duration on microhole drilling in glass by Bessel beam^[47]; (c) Microholes drilled with single pulse Bessel beam (left) and Gaussian beam (right) in PMMA^[48]; (d) The shockwave evolution inside material with Bessel (left) and Gaussian (right) laser beam drilling^[50]; (e) The fabrication results of Bessel-like beams with flexibly adjustable focal depth realized by changing the phase with SLM^[51]

Fig. 6. Application of femtosecond laser drilling sub-wavelength microhole arrays in transmittance enhancement and anti-reflection. (a) Sub-wavelength periodic structures of different morphologies fabricated on sapphire^[57]; (b) SEM of upper surface and section of periodic microhole arrays on CdSSe^[58]; (c) The simulated transmittance of anti-reflection structures with different morphology structures of 3 μm period^[59]

Fig. 7. Application of femtosecond laser microhole drilling in material cutting. (a) Cutting 700 μm thick Corning Eagle 2000 glass by double-layer microhole arrays^[66]; (b) The cutting results of D263T glass by femtosecond laser pulse-trains^[67]; (c) The crack on sapphire formed by Bessel beam with different pulse durations^[66]; (d) The low surface roughness cutting results realized by the axicon with large angle^[70]

Fig. 8. Femtosecond laser microhole drilling technology has also been applied to oil and water separation, fog collection, gas transportation. (a) The schematic illustration of fabricating Janus membrane with different wetting properties on both sides for oil-water separation^[71]; (b) The schematic of the femtosecond laser ablation and nanoparticle deposition, which realizing unidirectional transportation of underwater bubbles^[74]; (c) The schematic illustration of the fabrication process of the hierarchical hydrophilic/hydrophobic/bumpy Janus (HHHBJ) membrane used to fog collection^[76]