Electrons dynamics control micro-hole drilling using temporally/spatially shaped femtosecond laser

Zhang Chao; Li Min; Ye Baichen; Wu Jianying; Wang Zhi; Li Xiaowei

doi:10.12086/oee.2022.210389

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Zhang C, Li M, Ye B C, et al. Electrons dynamics control micro-hole drilling using temporally/spatially shaped femtosecond laser[J]. Opto-Electron Eng, 2022, 49(2): 210389. doi: 10.12086/oee.2022.210389

Citation:

Zhang C, Li M, Ye B C, et al. Electrons dynamics control micro-hole drilling using temporally/spatially shaped femtosecond laser[J]. Opto-Electron Eng, 2022, 49(2): 210389. doi: 10.12086/oee.2022.210389

Electrons dynamics control micro-hole drilling using temporally/spatially shaped femtosecond laser

Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing 100081, China

Fund Project: National Natural Science Foundation of China (NSFC) (52075041), Beijing Municipal Natural Science Foundation (JQ20015), and Beijing Outstanding Young Scientist Program (BJJWZYJH01201910007022)

More Information

Corresponding author: lixiaowei@bit.edu.cn

Received Date 03 December 2021

Revised Date 09 February 2022

Published Date 25 February 2022

Abstract

Abstract

As a common structure, microholes are widely used in various fields, including biomedical, aerospace, 3D packaging and so on. Femtosecond laser has unique advantages in drilling high-quality microhole due to its ultra-short pulse duration and ultra-high peak power. This review covers temporally/spatially shaped femtosecond laser microhole drilling methods and their applications over the past decade, including femtosecond laser temporally/spatially shaped methods, temporally/spatially shaped femtosecond laser microhole drilling based on electrons dynamics control, and the applications of microhole in transmittance enhancement and anti-reflection, material cutting, oil/water separation, fog collection and gas collection. Furthermore, present challenges and future research opportunities in this field are analyzed.
- femtosecond laser /
- electrons dynamic control /
- micro-hole drilling /
- temporally/spatially shaping /
- micro-hole applications

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References

[1]	Fei Z Z, Hu X, Choi H W, et al. Micronozzle array enhanced sandwich electroporation of embryonic stem cells[J]. Anal Chem, 2010, 82(1): 353−358. Google Scholar
[2]	An R, Hoffman M D, Donoghue M A, et al. Water-assisted femtosecond laser machining of electrospray nozzles on glass microfluidic devices[J]. Opt Express, 2008, 16(19): 15206−15211. doi: 10.1364/OE.16.015206 CrossRef Google Scholar
[3]	Vong T H, Schoffelen S, van Dongen S F M, et al. A DNA-based strategy for dynamic positional enzyme immobilization inside fused silica microchannels[J]. Chem Sci, 2011, 2(7): 1278−1285. doi: 10.1039/c1sc00146a CrossRef Google Scholar
[4]	Baheri S, Tabrizi S P A, Jubran B A. Film cooling effectiveness from trenched shaped and compound holes[J]. Heat Mass Transfer, 2008, 44(8): 989−998. doi: 10.1007/s00231-007-0341-9 CrossRef Google Scholar
[5]	Landgraf R, Rieske R, Danilewsky A N, et al. Laser drilled through silicon vias: crystal defect analysis by synchrotron x-ray topography[C]//Proceedings of the 2nd Electronics System-Integration Technology Conference, 2008: 1023–1028. Google Scholar
[6]	Salah K. TGV versus TSV: a comparative analysis[C]//Proceedings of the 3rd International Conference on Advances in Computational Tools for Engineering Applications (ACTEA), 2016: 49–53. Google Scholar
[7]	Lai M F, Li S W, Shih J Y, et al. Wafer-level three-dimensional integrated circuits (3D IC): Schemes and key technologies[J]. Microelectron Eng, 2011, 88(11): 3282−3286. doi: 10.1016/j.mee.2011.05.036 CrossRef Google Scholar
[8]	Egashira K, Mizutani K. Micro drilling of monocrystalline silicon using a cutting tool[J]. Precis Eng, 2002, 26(3): 263−268. doi: 10.1016/S0141-6359(01)00113-1 CrossRef Google Scholar
[9]	Cao X D, Kim B H, Chu C N. Micro-structuring of glass with features less than 100 μm by electrochemical discharge machining[J]. Precis Eng, 2009, 33(4): 459−465. doi: 10.1016/j.precisioneng.2009.01.001 CrossRef Google Scholar
[10]	Spinney P S, Howitt D G, Smith R L, et al. Nanopore formation by low energy focused electron beam machining[J]. Nanotechnology, 2010, 21(37): 375301. doi: 10.1088/0957-4484/21/37/375301 CrossRef Google Scholar
[11]	Sebastiani M, Eberl C, Bemporad E, et al. Depth resolved residual stress analysis of thin coatings by a new FIB-DIC method[J]. Mater Sci Eng A, 2011, 528(27): 7901−7908. doi: 10.1016/j.msea.2011.07.001 CrossRef Google Scholar
[12]	Zhang Y, Li S C, Chen G Y, et al. Experimental observation and simulation of keyhole dynamics during laser drilling[J]. Opt Laser Technol, 2013, 48: 405−414. doi: 10.1016/j.optlastec.2012.10.039 CrossRef Google Scholar
[13]	王国彪. 光制造科学与技术的现状和展望[J]. 机械工程学报, 2011, 47(21): 157−169. Google Scholar Wang G B. Photonic manufacturing science & technology: overview and outlook[J]. J Mechan Eng, 2011, 47(21): 157−169. Google Scholar
[14]	Ultrafast laser processing: from micro-to nanoscale[M]. CRC Press, 2013. Google Scholar
[15]	Sugioka K, Cheng Y. Ultrafast lasers-reliable tools for advanced materials processing[J]. Light Sci Appl, 2014, 3(4): e149. Google Scholar
[16]	Malinauskas M, Žukauskas A, Hasegawa S, et al. Ultrafast laser processing of materials: from science to industry[J]. Light Sci Appl, 2016, 5(8): e16133. doi: 10.1038/lsa.2016.133 CrossRef Google Scholar
[17]	Yang Q X, Liu H L, He S, et al. Circular cladding waveguides in Pr: YAG fabricated by femtosecond laser inscription: Raman, luminescence properties and guiding performance[J]. Opto-Electron Adv, 2021, 4(2): 200005. Google Scholar
[18]	Chen L, Cao K Q, Li Y L, et al. Large-area straight, regular periodic surface structures produced on fused silica by the interference of two femtosecond laser beams through cylindrical lens[J]. Opto-Electron Adv, 2021, 4(12): 200036. doi: 10.29026/oea.2021.200036 CrossRef Google Scholar
[19]	Livakas N, Skoulas E, Stratakis E. Omnidirectional iridescence via cylindrically-polarized femtosecond laser processing[J]. Opto-Electron Adv, 2020, 3(5): 190035. doi: 10.29026/oea.2020.190035 CrossRef Google Scholar
[20]	Jia Y C, Wang S X, Chen F. Femtosecond laser direct writing of flexibly configured waveguide geometries in optical crystals: fabrication and application[J]. Opto-Electron Adv, 2020, 3(10): 190042. doi: 10.29026/oea.2020.190042 CrossRef Google Scholar
[21]	Jiang L, Wang A D, Li B, et al. Electrons dynamics control by shaping femtosecond laser pulses in micro/nanofabrication: modeling, method, measurement and application[J]. Light Sci Appl, 2018, 7(2): 17134. doi: 10.1038/lsa.2017.134 CrossRef Google Scholar
[22]	Sundaram S K, Mazur E. Inducing and probing non-thermal transitions in semiconductors using femtosecond laser pulses[J]. Nat Mater, 2002, 1(4): 217−224. doi: 10.1038/nmat767 CrossRef Google Scholar
[23]	Gattass R R, Mazur E. Femtosecond laser micromachining in transparent materials[J]. Nat Photonics, 2008, 2(4): 219−225. doi: 10.1038/nphoton.2008.47 CrossRef Google Scholar
[24]	Chichkov B N, Momma C, Nolte S, et al. Femtosecond, picosecond and nanosecond laser ablation of solids[J]. Appl Phys A, 1996, 63(2): 109−115. doi: 10.1007/BF01567637 CrossRef Google Scholar
[25]	Gamaly E G. Femtosecond Laser-Matter Interaction: Theory, Experiments and Applications[M]. London: Pan Stanford, 2011. Google Scholar
[26]	Wu D, Wu S Z, Xu J, et al. Hybrid femtosecond laser microfabrication to achieve true 3D glass/polymer composite biochips with multiscale features and high performance: the concept of ship-in-a-bottle biochip[J]. Laser Photonics Rev, 2014, 8(3): 458−467. doi: 10.1002/lpor.201400005 CrossRef Google Scholar
[27]	Liu P J, Jiang L, Hu J, et al. Etching rate enhancement by shaped femtosecond pulse train electron dynamics control for microchannels fabrication in fused silica glass[J]. Opt Lett, 2013, 38(22): 4613−4616. doi: 10.1364/OL.38.004613 CrossRef Google Scholar
[28]	Liu W, Hu J, Jiang L, et al. Formation of laser-induced periodic surface nanometric concentric ring structures on silicon surfaces through single-spot irradiation with orthogonally polarized femtosecond laser double-pulse sequences[J]. Nanophotonics, 2021, 10(4): 1273−1283. doi: 10.1515/nanoph-2020-0568 CrossRef Google Scholar
[29]	Du K, Li X W, Zhang H, et al. Controllable photon energy deposition efficiency in laser processing of fused silica by temporally shaped femtosecond pulse: experimental and theoretical study[J]. Opt Laser Technol, 2020, 128: 106265. doi: 10.1016/j.optlastec.2020.106265 CrossRef Google Scholar
[30]	Dromey B, Zepf M, Landreman M, et al. Generation of a train of ultrashort pulses from a compact birefringent crystal array[J]. Appl Opt, 2007, 46(22): 5142−5146. doi: 10.1364/AO.46.005142 CrossRef Google Scholar
[31]	Wang A D, Jiang L, Li X W, et al. Simple and robust generation of ultrafast laser pulse trains using polarization-independent parallel-aligned thin films[J]. Opt Laser Technol, 2018, 101: 298−303. doi: 10.1016/j.optlastec.2017.11.003 CrossRef Google Scholar
[32]	Wang Z P, Li X W, Jiang L, et al. High-quality micropattern printing by interlacing-pattern holographic femtosecond pulses[J]. Nanophotonics, 2020, 9(9): 2895−2904. doi: 10.1515/nanoph-2020-0138 CrossRef Google Scholar
[33]	Li B H, Li X W, Zhao R Z, et al. Polarization multiplexing terahertz metasurfaces through spatial femtosecond laser‐shaping fabrication[J]. Adv Opt Mater, 2020, 8(12): 2000136. doi: 10.1002/adom.202000136 CrossRef Google Scholar
[34]	Zambon V, McCarthy N, Piché M. Fabrication of photonic devices directly written in glass using ultrafast Bessel beams[C]//Photonics North 2008. SPIE, 2008, 7099: 720-724. Google Scholar
[35]	Durnin J, Miceli Jr J J, Eberly J H. Diffraction-free beams[J]. Phys Rev Lett, 1987, 58(15): 1499−1501. doi: 10.1103/PhysRevLett.58.1499 CrossRef Google Scholar
[36]	Gori F, Guattari G, Padovani C. Bessel-gauss beams[J]. Opt Commun, 1987, 64(6): 491−495. doi: 10.1016/0030-4018(87)90276-8 CrossRef Google Scholar
[37]	Herman R M, Wiggins T A. High-efficiency diffractionless beams of constant size and intensity[J]. Appl Opt, 1994, 33(31): 7297−7306. doi: 10.1364/AO.33.007297 CrossRef Google Scholar
[38]	Duocastella M, Arnold C B. Bessel and annular beams for materials processing[J]. Laser Photonics Rev, 2012, 6(5): 607−621. doi: 10.1002/lpor.201100031 CrossRef Google Scholar
[39]	Stoian R, Boyle M, Thoss A, et al. Laser ablation of dielectrics with temporally shaped femtosecond pulses[J]. Appl Phys Lett, 2002, 80(3): 353−355. doi: 10.1063/1.1432747 CrossRef Google Scholar
[40]	Jiang L, Liu P J, Yan X L, et al. High-throughput rear-surface drilling of microchannels in glass based on electron dynamics control using femtosecond pulse trains[J]. Opt Lett, 2012, 37(14): 2781−2783. doi: 10.1364/OL.37.002781 CrossRef Google Scholar
[41]	Jiang L, Fang J Q, Cao Q, et al. Femtosecond laser high-efficiency drilling of high-aspect-ratio microholes based on free-electron-density adjustments[J]. Appl Opt, 2014, 53(31): 7290−7295. doi: 10.1364/AO.53.007290 CrossRef Google Scholar
[42]	Götte N, Winkler T, Meinl T, et al. Temporal Airy pulses for controlled high aspect ratio nanomachining of dielectrics[J]. Optica, 2016, 3(4): 389−395. doi: 10.1364/OPTICA.3.000389 CrossRef Google Scholar
[43]	Del Hoyo J, Meyer R, Furfaro L, et al. Nanoscale confinement of energy deposition in glass by double ultrafast Bessel pulses[J]. Nanophotonics, 2021, 10(3): 1089−1097. doi: 10.1515/nanoph-2020-0457 CrossRef Google Scholar
[44]	Wang Z, Jiang L, Li X W, et al. High-throughput microchannel fabrication in fused silica by temporally shaped femtosecond laser Bessel-beam-assisted chemical etching[J]. Opt Lett, 2018, 43(1): 98−101. doi: 10.1364/OL.43.000098 CrossRef Google Scholar
[45]	Courvoisier F, Lacourt P A, Jacquot M, et al. Surface nanoprocessing with nondiffracting femtosecond Bessel beams[J]. Opt Lett, 2009, 34(20): 3163−3165. doi: 10.1364/OL.34.003163 CrossRef Google Scholar
[46]	Bhuyan M K, Courvoisier F, Lacourt P A, et al. High aspect ratio nanochannel machining using single shot femtosecond Bessel beams[J]. Appl Phys Lett, 2010, 97(8): 081102. doi: 10.1063/1.3479419 CrossRef Google Scholar
[47]	Bhuyan M K, Velpula P K, Colombier J P, et al. Single-shot high aspect ratio bulk nanostructuring of fused silica using chirp-controlled ultrafast laser bessel beams[J]. Appl Phys Lett, 2014, 104(2): 021107. doi: 10.1063/1.4861899 CrossRef Google Scholar
[48]	Zhao W W, Li X W, Xia B, et al. Single-pulse femtosecond laser Bessel beams drilling of high-aspect-ratio microholes based on electron dynamics control[J]. Proc SPIE, 2014, 9296: 92960Q. Google Scholar
[49]	He F, Yu J J, Tan Y X, et al. Tailoring femtosecond 1.5-μm Bessel beams for manufacturing high-aspect-ratio through-silicon vias[J]. Sci Rep, 2017, 7(1): 40785. doi: 10.1038/srep40785 CrossRef Google Scholar
[50]	Wang G Y, Yu Y W, Jiang L, et al. Cylindrical shockwave-induced compression mechanism in femtosecond laser Bessel pulse micro-drilling of PMMA[J]. Appl Phys Lett, 2017, 110(16): 161907. doi: 10.1063/1.4981248 CrossRef Google Scholar
[51]	Yao Z L, Jiang L, Li X W, et al. Non-diffraction-length, tunable, Bessel-like beams generation by spatially shaping a femtosecond laser beam for high-aspect-ratio micro-hole drilling[J]. Opt Exp, 2018, 26(17): 21960−21968. doi: 10.1364/OE.26.021960 CrossRef Google Scholar
[52]	Wang H R, Zhang F, Ding K W, et al. Non-diffraction-length Bessel-beam femtosecond laser drilling of high-aspect-ratio microholes in PMMA[J]. Optik, 2021, 229: 166295. doi: 10.1016/j.ijleo.2021.166295 CrossRef Google Scholar
[53]	Yashunin D A, Malkov Y A, Mochalov L A, et al. Fabrication of microchannels in fused silica using femtosecond Bessel beams[J]. J Appl Phys, 2015, 118(9): 093106. doi: 10.1063/1.4929649 CrossRef Google Scholar
[54]	Park M S, Lee Y, Kim J K. One-step preparation of antireflection film by spin-coating of polymer/solvent/nonsolvent ternary system[J]. Chem Mater, 2005, 17(15): 3944−3950. doi: 10.1021/cm0500758 CrossRef Google Scholar
[55]	Raut H K, Ganesh V A, Nair A S, et al. Anti-reflective coatings: a critical, in-depth review[J]. Energy Environ Sci, 2011, 4(10): 3779−3804. doi: 10.1039/c1ee01297e CrossRef Google Scholar
[56]	Tarabrin M K, Bushunov A A, Lazarev V A, et al. Fabrication of anti-reflection microstructures on ZnSe single crystal by using femtosecond laser pulses[C]//Laser Science 2017, 2017: JTu2A. 20. Google Scholar
[57]	Li Q K, Cao J J, Yu Y H, et al. Fabrication of an anti-reflective microstructure on sapphire by femtosecond laser direct writing[J]. Opt Lett, 2017, 42(3): 543−546. doi: 10.1364/OL.42.000543 CrossRef Google Scholar
[58]	Bushunov A A, Tarabrin M K, Lazarev V A, et al. Fabrication of anti-reflective microstructures on chalcogenide crystals by femtosecond laser ablation[J]. Opt Mater Express, 2019, 9(4): 1689−1697. doi: 10.1364/OME.9.001689 CrossRef Google Scholar
[59]	Zhang F, Wang H R, Wang C, et al. Direct femtosecond laser writing of inverted array for broadband antireflection in the far-infrared[J]. Opt Lasers Eng, 2020, 129: 106062. doi: 10.1016/j.optlaseng.2020.106062 CrossRef Google Scholar
[60]	Li X, Li M, Liu H J, et al. Fabrication of an anti-reflective microstructure on ZnS by femtosecond laser Bessel beams[J]. Molecules, 2021, 26(14): 4278. doi: 10.3390/molecules26144278 CrossRef Google Scholar
[61]	Matsumaru K, Takata A, Ishizaki K. Advanced thin dicing blade for sapphire substrate[J]. Sci Technol Adv Mater, 2005, 6(2): 120−122. doi: 10.1016/j.stam.2004.11.002 CrossRef Google Scholar
[62]	Borowiec A, Haugen H K. Femtosecond laser micromachining of grooves in indium phosphide[J]. Appl Phys A, 2004, 79(3): 521−529. doi: 10.1007/s00339-003-2377-0 CrossRef Google Scholar
[63]	Shin H, Kim D. Cutting thin glass by femtosecond laser ablation[J]. Opt Laser Technol, 2018, 102: 1−11. Google Scholar
[64]	Li J Z, Ertorer E, Herman P R. Ultrafast laser burst-train filamentation for non-contact scribing of optical glasses[J]. Opt Express, 2019, 27(18): 25078−25090. doi: 10.1364/OE.27.025078 CrossRef Google Scholar
[65]	Dogan Y, Madsen C K. Optimization of ultrafast laser parameters for 3D micromachining of fused silica[J]. Opt Laser Technol, 2020, 123: 105933. doi: 10.1016/j.optlastec.2019.105933 CrossRef Google Scholar
[66]	Ahmed F, Lee M S, Sekita H, et al. Display glass cutting by femtosecond laser induced single shot periodic void array[J]. Appl Phys A, 2008, 93(1): 189−192. doi: 10.1007/s00339-008-4672-2 CrossRef Google Scholar
[67]	Mishchik K, Beuton R, Caulier O D, et al. Improved laser glass cutting by spatio-temporal control of energy deposition using bursts of femtosecond pulses[J]. Opt Express, 2017, 25(26): 33271−33282. doi: 10.1364/OE.25.033271 CrossRef Google Scholar
[68]	Rapp L, Meyer R, Furfaro L, et al. High speed cleaving of crystals with ultrafast Bessel beams[J]. Opt Express, 2017, 25(8): 9312−9317. doi: 10.1364/OE.25.009312 CrossRef Google Scholar
[69]	Shin H, Kim D. Strength of ultra-thin glass cut by internal scribing using a femtosecond Bessel beam[J]. Opt Laser Technol, 2020, 129: 106307. doi: 10.1016/j.optlastec.2020.106307 CrossRef Google Scholar
[70]	Li Z Q, Wang X F, Wang J L, et al. Stealth dicing of sapphire sheets with low surface roughness, zero kerf width, debris/crack-free and zero taper using a femtosecond Bessel beam[J]. Opt Laser Technol, 2021, 135: 106713. doi: 10.1016/j.optlastec.2020.106713 CrossRef Google Scholar
[71]	Zhang Z, Zhang Y H, Fan H, et al. A Janus oil barrel with tapered microhole arrays for spontaneous high-flux spilled oil absorption and storage[J]. Nanoscale, 2017, 9(41): 15796−15803. doi: 10.1039/C7NR03829A CrossRef Google Scholar
[72]	Ren F F, Li G Q, Zhang Z, et al. A single-layer Janus membrane with dual gradient conical micropore arrays for self-driving fog collection[J]. J Mater Chem A, 2017, 5(35): 18403−18408. doi: 10.1039/C7TA04392A CrossRef Google Scholar
[73]	Chen C, Shi L A, Huang Z C, et al. Microhole‐arrayed PDMS with controllable wettability gradient by one‐step femtosecond laser drilling for ultrafast underwater bubble unidirectional self‐transport[J]. Adv Mater Interfaces, 2019, 6(12): 1900297. doi: 10.1002/admi.201900297 CrossRef Google Scholar
[74]	Hu Y L, Qiu W X, Zhang Y Y, et al. Channel-controlled Janus membrane fabricated by simultaneous laser ablation and nanoparticles deposition for underwater bubbles manipulation[J]. Appl Phys Lett, 2019, 114(17): 173701. doi: 10.1063/1.5095615 CrossRef Google Scholar
[75]	Ibrahim M H, El-Naas M H, Zhang Z E, et al. CO₂ capture using hollow fiber membranes: a review of membrane wetting[J]. Energy Fuels, 2018, 32(2): 963−978. doi: 10.1021/acs.energyfuels.7b03493 CrossRef Google Scholar
[76]	Su Y H, Chen L, Jiao Y L, et al. Hierarchical hydrophilic/hydrophobic/bumpy Janus membrane fabricated by femtosecond laser ablation for highly efficient fog harvesting[J]. ACS Appl Mater Interfaces, 2021, 13(22): 26542−26550. doi: 10.1021/acsami.1c02121 CrossRef Google Scholar

Overview

Overview

As a common structure, microholes are widely used in biomedical, microfluidic devices, aerospace and 3D packaging fields. As the performance requirements of various functional devices are more and more strict in practical applications, the requirements for the quality and depth-diameter ratio of microhole processing also become much higher, which makes the microhole processing in manufacturing extremely challenging. In view of the increasingly strict requirements of microhole indicators, selecting a suitable microhole processing method is the key.

At present, the commonly used microhole drilling methods are mechanical drilling, electric spark drilling, electron beam drilling, focused ion beam drilling, laser drilling and electro discharge machining (EDM). Mechanical drilling is easy to operate, but it is difficult to process microholes with small diameters and high depth-diameter ratios. EDM drilling is only suitable for conductive materials and is difficult to process. Electron beam and focused ion beam drilling can achieve micro holes with nanometer to submicron precision, but the conditions are harsh. The equipment is expensive, and the processing efficiency is slow. Laser drilling has the characteristics of non-contact, wide material adaptability and high processing efficiency, but the microholes processed by continuous laser and long pulse laser have a certain heat affected zone.

Femtosecond laser is different from the continuous laser and long pulse laser. It has characteristics of ultra-short pulse duration and ultra-high peak power, enabling high-quality processing capacity and wide material adaptability. Compared with traditional processing methods, femtosecond laser has the following three significant advantages: (1) Small thermal effect and high processing quality; (2) Strong nonlinear effect, wide range of material processing and higher processing resolution; (3) The "true" 3D processing. When the femtosecond laser is focused inside the transparent medium, only the material near the focal point can be modified or removed, so the "true" 3D machining of arbitrary complex structures can be achieved with femtosecond laser. Therefore, femtosecond laser provides a new possibility for high-quality microhole drilling. Unshaped Gaussian laser microhole drilling has the contradiction between small diameters and high depth-diameter ratios. Due to the precise and adjustable properties of femtosecond laser, its light field distribution can be controlled in terms of transient local electronic dynamic and subsequent phase transitions by temporally/spatially shaping. In this way, the microhole can be drilled to satisfy the requirements of both small diameter and high depth-diameter ratio.

In this paper, the processing methods regarding electrons dynamics control micro-hole drilling using temporally/spatially shaped femtosecond laser and the applications of microholes in transmittance enhancement and anti-reflection, material cutting, oil and water separation, fog collection and gas transportation are reviewed.