Modality of 3D printing which can be used for laser structuring of materials from resolution of tens-of-nanometers to tens-of-micrometers is realised by implementing ultra-short laser pulses of sub-1 ps duration. For example, laser polymerisation can be used to form 3D suspended bridges which have cross sections of only few tens-of-nanometers by direct write approach. A typical irradiance per pulse for 3D polymerisation is 0.5-1 TW/cm2. Laser ablation can be controlled with a similar precision at slightly higher irradiances on surface of metals, semiconductors and dielectrics. Uniquely for ultra-short laser pulses, a light – matter interaction can be controlled by wavelength, intensity, exposure dose (focal spot size and scanning speed), and chirp (spectral and temporal). This opens possibility to tailor polymerisation conditions by purely optical means via avalanche and multi-photon ionisation rather to rely on bio-toxic photo-initiators developed for resins and photo-resits polymerised under cw-laser or UV-lamp exposure. An ultra-short laser printing of photoinitiator-free polymers can find applications in bio-medical applications where resolution from sub-micrometres to tens-of-micrometres are typically required.
By tightly focussed femtosecond laser pulses inside transparent glass and crystalline hosts, a 3D confined modification of micro-volumes can be created. Those modified micro-volumes patterned in a 3D interconnected fashion are used to fabricate 3D channels by chemical wet etching in glasses and crystals. High pressure (which is the energy absorbed in a localised volume) and temperature conditions creates exotic phase materials which can be retrieved to ambient conditions due to ultrafast quenching.
Recent results in 3D material structuring by ultra-short laser pulses will be presented in a tutorial format with numerical estimates and illustrations of the key phenomena.

Saulius Juodkazis is a Professor and Director of the Nanotechnology facility at Swinburne’s Centre for Micro-Photonics. His current research is focused on applying principles of light-field enhancement and its spectral control for applications in micro-optics, sensing, solid-state lighting, and solar energy conversion.
Professor Juodkazis has contributed to the development of a three-dimensional laser printing with nano-/micro-scale precision using femtosecond laser for applications in opto-fluidic, micro-optics, optical memory, and photonic crystals. He has shown experimentally the creation of high-pressure density phases of materials using tightly focused ultra-short laser pulses. Currently, his research also includes nano-textured surfaces for sensing, bactericidal, and light harvesting applications.
Professor Juodkazis received his doctorate in experimental physics and material science jointly from Vilnius University (Lithuania) and Lyon-I University (France). He has also held previous tenured positions at the University of Tokushima and Hokkaido University, Japan, and is the author of ~500 peer-reviewed journal papers, reviews, and several book chapters. He is Fellow of OSA and SPIE and ChangJiang scholar.

One-step femtosecond laser ablation can directly create porous network microstructure on various polymer surfaces, including polyethylene terephthalate (PET), polymethylmethacrylate (PMMA), polyamide (PA), polycarbonate (PC), polyethylene (PE), and polylactic acid (PLA)，polyamide-6 (PA6). Take PET for example, as shown in figure, the surface was fully covered by interconnected pores with the diameter of several hundred nanometers after femtosecond laser ablation. As the porous surface was further lowered its surface free energy and infused with lubricating liquid, a slippery surface was successfully fabricated. The SLIPS surface had excellent liquid-repellent ability since various liquids could can easily slide down the 10° tilted SLIPS. Compared to the previous reported slippery surfaces, the porous layer and the substrate layer of our SLIPS are inherent one material. Moreover, even though the SLIPS suffers from heavily physical damage, the surface can rapidly self-repair without any additional treatment and obtain slippery property again. Furthermore, the slippery PET surface could completely inhibit C6 glioma’s growth. Thus, the developed SLIPS promises to contribute to the achievement of omniphobic materials in selfcleaning, antifouling, biomedical devices, and fuel transport.

Feng Chen is a full professor of Electronic Engineering at Xi'an Jiaotong University, where he directs the Femtosecond Laser Microfabrication Laboratory and has severed as deputy director of the International Joint Research Center for Micro/Nano Manufacturing and Measurement Technologies. Chen received the B.S. degree in physics from Sichuan University, China in 1991 and received the Ph. D. in Optics from Chinese Academy of Science in 1997. He began to work for Chinese Academy of Science (1991 to 2002), where he was promoted to a full professor in 1999. In 2002, Dr. Chen joined the Xi'an Jiaotong University, where he became a group leader. He had been a full Professor of Electronics Engineering at Xian Jiaotong University since 2002. His current research interests are femtosecond laser microfabrication and Bionic Microfabrication. Dr. Chen took charge in over 30 research projects, and has published more than 200 peer-reviewed papers.

3D µ-printing is a versatile technology allowing to create structures to study light matter interaction. I will present two examples. First, tailored disorder in photonic structures, which decides, if a structure presents bright non-iridescent color or if it shows brilliant whiteness. I will discuss a model system, which characteristically demonstrates the influence of tailored disorder. This model system explains the optical properties of the white beetle scales’ structure based on small one-dimensional Bragg reflectors with tailored disorder in layer thickness and filling fraction. Depending on the parameters it is able to also explain the noniridescent colors found, e.g. in certain butterflies. Second, I will demonstrate our first results on 3D µ-printing of metallic structures, for which we use specially developed photo resists. Spatial resolution down to 500 nm is already close to results also achieved with conventional polymeric materials.

Since 2013 Head of Department, Fraunhofer Institute for Industrial Mathematics (ITWM), Kaiserslautern
Since 2010 Professor (W3), TU Kaiserslautern
2007 – 2014 CTO, Nanoscribe GmbH
2005 – 2010 Head of a DFG Emmy Noether group, KIT, Karlsruhe
2001 – 2004 Postdoc, KIT Karlsruhe and University of Toronto
1998 – 2001 Ph.D. student, University Karlsruhe (TH)
1992 – 1998 Studying physics an University Karlsruhe (TH)

In the last twenty years, femtosecond laser-induced periodic nanoripples in metal, semiconductor, and dielectrics have been widely studied. At present, people mainly pay attentions to the following problems: one is the mechanism of femtosecond laser-induced periodic ripples; the other is the efficient fabrication of periodic nanostructures and their applications in the fields of polarizing optical micro-elements, data storage, broadband absorption, enhanced photoluminescence, surface coloring, and wettability.
We developed an ultrafast imaging system with high temporal resolution and high spatial resolution, and studied the ultrafast imaging of periodic ripples induced by a single  femtosecond laser pulse on semiconductor and metal surfaces.The results show that the periodic distribution of laser field caused by surface plasmon polarization and the periodic energy deposition play a key role in the formation of periodic ripples.
We reports the formation of periodic subwavelength ripples on a silicon surface induced by a single-shaped 800-nm femtosecond laser pulse. The temporally shaped femtosecond laser pulse can enhance the excitation of surface plasmon polaritons and the periodic energy deposition while reducing residual thermal effects on the silicon surface, eventually resulting in periodic ripples at the center of the ablation area.
By using the interference of double column lens, a large area regular grating structure was prepared on the semiconductor and glass surface with high efficiency.

Jia Tianqing’s research focuses on the femtosecond laser micro/nanofabrication. He reports more than 100 papers on the ultrafast dynamics of dielectrics and semiconductors ablated by femtosecond laser pulses, fs laser-induced periodeic nanostructures. Recently, he begin study the processing of cooling holes of engine leaf of air plane by using ns laser and fs laser. He obtained his doctoral degree in Tongji University, Sep, 2000. In 2000-2005, He made his research in Shanghai Institute of Optics and Fine Mechanisms. In 2005-2007, he studied in the Tokyo University as a JSPS fellow. He works as a professor at East China Normal University since September 2007.

Ultrafast laser offers the advantages of reduced recast/microcracks and minimized heat affected zones around ablation section due to its ultra-short pulse durations and ultra-high power densities, which is obviously different from melting region caused by long-pulse laser and can considerably increase the fabrication precision and quality eventually. By manipulating the spatial shape of ultrafast laser pulses either, the electron excitation processes during laser-material interactions can be precisely controlled. As a result, high-quality, high-aspect-ratio, high-efficient micro/nano-fabrication method can be achieved, for example: we proposed to: 1) control the spatial distribution of electron density by spatially shaping the femtosecond laser pulses, with which metallic nanowires with a minimum width of 56 nm can be fabricated; 2) adjust optical near-field distribution and the corresponding electron generation on fabricated material surface, by which the periods, orientations and structures of the surface ripples can be effectively adjusted; 3) high-quality microholes with a diameter of 1.5μm and an aspect ratio of 1000:1 are fabricated by a spatially shaped single femtosecond laser pulse. It takes 42 min to fabricate 251,001 holes in a 1 cm × 1 cm area, which is very uniform in size and shape.

Xiaowei Li is currently a Professor of Department of Mechanical Engineering at the Beijing Institute of Technology. His research activities are mainly focused on laser micro/nano fabrication and related applications. Dr. Li published 46 SCI-indexed papers in mainstream international journals. He received the Second Prize of Natural Science Award (the 5th co-PI), China in 2016, Young Elite Scientists Award, China Association for Science and Technology in 2017, and the First Prize of Natural Science Award (the 4th co-PI), Ministry of Education, China in 2014.

Photochemical processes induced by multiphoton absorption of femtosecond laser pulses, such as photopolymerization, photodegradation and photografting, offer numerous possibilities for precise 3D structuring of polymeric materials. The possibility to access multiple length scales down to a sub-micrometer feature size in a single process is especially relevant for biomedical applications. Some of the intrinsic bottlenecks of multiphoton lithography processes for these applications are relatively low throughput, mainly related to high spatial resolution, and potentially cyto- or phototoxic material components. In this contribution, our recent progress on the development of multiphoton lithography and related materials for biomedical applications will be discussed. The presentation is supported by numerous examples.

Prof. Aleksandr Ovsianikov is a head of the research group 3D Printing and Biofabrication at the TU Wien (Vienna, Austria) and a member of the Austrian Cluster for Tissue Regeneration (http://www.tissue-regeneration.at). His research is dealing with the use of additive manufacturing technologies and bioprinting for tissue engineering and regeneration.
Dr. Ovsianikov has background in laser physics and material processing with femtosecond lasers. A particular focus his current research is the development of multiphoton lithography technologies for engineering of biomimetic 3D cell culture matrices and realization of novel tissue engineering scaffolds. He was awarded a prestigious Starting Grant in 2012 and a Consolidator Grant in 2017 from the European Research Council (ERC) for projects aimed at these topics (http://amt.tuwien.ac.at/Ovsianikov)

The interaction between ultrafast laser and the transparent matrix has resulted in creating various three-dimensional functional photonic structures as well as inducing unprecedented phenomena. In the past years, our group observed many interesting structures and phenomena by studying this light-matter interaction. In the presentation, I will show our work about generation of self-assembled grating nanostructures by ultrafast laser micromachining. We found that self-assembled nanogratings can be produced in different types of transparent solids, such as fused silica, GeO2 glass and multicomponent glass. Especially, a new type of crystallite-based grating nanostructures was created in an unconventional multicomponent glass. These nanogratings were organized as periodically assembled crystalline and amorphous phases, which was in contrast with the structural deficiency-based nanogratings in the fused silica and GeO2 glass. The crystallization-assisted component in the glass strongly contributed to the creation of nanogratings. Furthermore, picosecond laser rather than femtosecond laser was established to be much more suitable for creating nanogratings in the glass, proving the critical role of thermal accumulation during nanoscale crystallization. Finally, nanogratings were demonstrated to be a broadband variable near-infrared optical attenuator with high attenuation ratio, indicating the potential application of nanogratings in optical information processing at communication wavelengths. These findings open new avenues for fabricating nanogratings in functional glasses for advanced integrated photonics and also offer information for revealing the mechanism of nanograting formation.

Dr. Dezhi Tan got his BS and PhD in Materials Science and Engineering in the Zhejiang University in 2009 and 2014, respectively. Then, he joined in Montreal Polytechnical as a postdoctor (2015, Canada), JSPS Fellow in Kyoto University (2016-2017, Japan) and research professor in IBS (2018, Korea). He is an assistant professor in Zhejiang University now. His fabricated various functional nanomaterials and nanostructures by femtosecond laser in liquid and transparent solids in Zhejiang University. He also worked on optoelectronic properties and applications of two-dimensional materials and their heterostructures for several years. Now, he is working on generating novel functional photonic nanostructures by ultrafast laser as well as investigating the mechanisms. He is also interested in the interaction between 2D materials and light.

Manipulating the material states with femtosecond laser illumination is a promising routine to create new states that are not accessible in equilibrium. To harness the power of possibility to engineer materials with light, it is key to understand how the energy transfers between different degrees of freedom and how the hierarchy of the energy transfer shapes the behaviors of a material. In this talk, I will take the laser-induced ultrafast demagnetization in ferromagnetic metals as an example and show how the laser illumination leads to the loss of magnetic order in femtoseconds. Here, by combining time- and angle-resolved photoelectron spectroscopy and ultrafast magneto-optical spectroscopy, we showed that the laser-induced ultrafast demagnetization in transition metal Ni is essentially of a phase transition of the coupled electron and spin system. In our results, we not only explained the fluence-dependent time constants, but also revealed that the critical phenomena of phase transition play an important role in the phase transition, which includes the critical fluence to induce phase transition and the divergence of the heat capacity, etc. This is the first time such observations become available. Surprisingly, our results indicate a strong connection between the non-equilibrium laser-induced dynamics and the material properties under thermal equilibrium, implying potential universality of our findings. By comparing with the ultrafast magneto-optical spectroscopy results, we found possible coexistence of the ferro- and paramagnetic states at the critical point of the phase transition. This can be studied by the next-generation space-time-resolved spectroscopic technique.

2018.1 – now Department of Physics, Fudan University Professor
2014.8 – 2018.1 JILA, University of Colorado, Boulder Postdoc
2008.8 – 2014.8 Department of Physics and Astronomy, Michigan State University Ph.D
2005.9 – 2008.6 Department of Physics, Fudan University Master Degree
2001.9 – 2005.6 Department of Physics, Fudan University Bachelor Degree
Honors:
Humboldt research fellowship 2019 1000 Talent program 2018 Shanghai "Eastern Scholar" distinguished Professor 2017

Femtosecond laser induced two-photon polymerization (TPP) has been proved to be a powerful microfabrication technique with high efficiency and quality. However, the main drawback of TPP technique is its low fabrication efficiency caused by the point-to-point raster scanning strategy, which seriously restricts its applications. In order to overcome the disadvantages, SLM-based (spatial light modulator) 2D-3D laser intensity patterns (e.g., mutlifoci or arbitrary patterns) were proposed to significantly speed up the fabrication process by several orders of magnitude, owing to its capability to dynamically update the intensity distributions in the focal plane by modifying the phase of incident light. A series of 2D-3D functional microdevices such as Damman grating, microfilter and flower-like microtube arrays were rapidly fabricated and showed various functions, such as beam splitting, particles filtering and cell manipulation.

Dong Wu is a professor of engineering science at University of Science and Technology of China. He obtained the fifth Chinese Thousand Youth Talents Plan. His current research interests are femtosecond laser 3D microfabrication for microoptical devices, microfluidic chips, micromachines, and biomimetic microstructures. Prof. Wu has published 80 papers in the international journals of Nature Photonics, Light: Sci & Appl.(Nature publishing group), PNAS, Laser Photon. Rev., Adv. Mater., Adv. Funct. Mater., Small, Lab Chip, Appl. Phys. Lett., Opt. Lett. and so on.

Femtosecond laser has proved to be an efficient tool to process crystal materials, which are widely used in many areas. Because of the characteristics of femtosecond laser, ultrashort pulse duration and ultrahigh peak power, the interaction process of laser pulse with crystal material is extremely complicated. It is an ultrafast dynamic process with ultrastrong light-matter interaction, which can overcome some physical limits. And it can lead to material modification of the crystals, accompanying with microstructuring and hyperdoping. For hyperdoping, the dopant concentration exceeds the solid solubility limit by several orders of magnitude. Therefore, the processed materials and devices made from which show some special properties. In this presentation, I will introduce our research progress of femtosecond laser processing of semiconductor silicon and dielectric lithium niobate, including processing principle and the devices made from them. Especially, I will focus on the new results, free-standing flexible photodetectors based on sulfur-hyperdoped ultrathin silicon, high responsive tellurium-hyperdoped black silicon photodiode with single-crystalline and uniform surface microstructure, and uniform periodic surface structures on lithium niobate crystal.

Qiang Wu is a professor of physics at School of Physics & TEDA Institute of Applied Physics, Nankai University (P. R. China). He received BSc in 2000 and PhD in 2005 from Nankai University and was a postdoc at Tufts University and MIT in 2007 and 2008. He was appointed full professor in 2013. His main research interest has been focused in ultrafast photonics from 2005, and now is focusing on: 1. femtosecond laser hyperdoping crystal and devices; 2. THz phonon polariton and THz wave; 3. ultrafast dynamics and imaging. He is also serving as an advisor of Boling Class, a partner of Pilot Scheme of Talent Training in Basic Sciences of China from 2010, and a member of editor board of Scientific Reports from 2013, Laser & Optoelectronics Progress from 2019.

Generally, structured beams are electromagnetic waves with specific phase or intensity profile. Vortex beam with spiral phase front, a kind of structured beam, is inherent to any wave phenomena and much interest has been focused on vortex fields in the past decades. In the past two decades, orbital angular momentum (OAM) of vortex beams has found numerous applications, including optical manipulation, quantum information processing, quantum cryptography, free-space information transfer and communications. Therefore, generating and measuring of OAM are crucial for all the fields associated with vortex beams. Besides the simple vortex beams, a superposition of OAM states has found important applications as well.
In this talk, I will give a brief review of the works on the generation of structured beams and its application on manipulation of nanoparticles in our group. Firstly, I will discuss a fundamental superposition and selection principle of coaxial multiple wave fields. Based on this principle, both optical and electron vortex beams with multiple OAM modes are generated experimentally. Secondly, I will discuss the generation of two kinds of novel vortex beams, namely, anomalous vortex beams and anomalous Bessel vortex beam, and both the intensity profile and the topological charge of such beams can vary during propagation, which is totally different with normal vortex beams. After that I will show the optical trapping of nanoparticles using anomalous vortex beams. At last, I discuss the experimental study on the patterning of ordered colloidal nanostructures on a large scale based on the combination of three-dimensional (3D) confined optical tweezers array and ultra-strong optical binding between nanoparticles.

Yuanjie Yang is currently a professor of Optics in the School of Physics, University of Electronic Science and Technology of China. He got his PhD degree from Sichuan University in 2008, and after that he had ever carried out postdoctoral research at University of St Andrews (UK), University of York (UK) and National University of Singapore. His research interest mainly focuses on optical vortex beams, orbital angular momentum, electron vortex beams and optical trapping. He has published 30 papers including Science, Physical Review Letters, Nanophotonics, Optics Letters, etc.

Over the past few decades the interaction between solid materials and ultrashort laser pulses has been a fascinating topic, and the potential of using ultrafast lasers in precision material processing was quickly recognized when high-power lasers became available. Nowadays ultrafast laser processing of materials is no longer a niche technology that finds usage only in laboratories. More and more applications have benefited from the unique characteristics of ultrafast laser induced modification and ablation. This talk will focus on the use of ultrafast lasers in manufacturing, which imposes challenges that need to be overcome by a better understanding of laser-material interaction and by technological advances of laser beam manipulation. This talk will present recent progress in ultrafast laser material processing, including micro-/nano-machining of dielectrics with a temporally-controlled pulse train, Bessel beam-induced photopolymerization, and a novel beam shaping technique using deformable mirrors. This work extends the capability of ultrafast lasers as a manufacturing tool, and puts forth a prospect of using lasers for manufacturing purposes in a more effective and productive manner.

Dr. Xiaoming Yu received his BS in Physics from Nankai University, China, in 2008, MS in Plasma Physics from Shanghai Institute of Optics and Fine Mechanics in 2012, and PhD in Industrial and Manufacturing Systems Engineering from Kansas State University in 2016. He joined the University of Central Florida in 2017. His research interest is in laser-matter interaction and laser-based advanced manufacturing.

Capturing the transient scenes at high imaging speed has been long-term dream by scientists. Especially, the introduction of electronic imaging sensors based on charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) technology can make the imaging speed up to 107 frames per second, but the frame rate of this technique is limited by the on-chip storage and electronic readout speed, and therefore further increasing frame rate is unable. In this talk, we would like to demonstrate a two-dimensional dynamic imaging technique, compressed ultrafast photography (CUP), which can capture non-repetitive transient events at up to 51012 frames per second. Compared with existing ultrafast imaging technique, the CUP technique has the prominent advantage of measuring transient scene with a single camera snapshot, and so it can observe the transient events with the temporal resolution in the range of picosecond. Considering CUP’s ability, it hopes to be applied in both fundamental

Shian Zhang is currently a Professor at East China Normal University. He received his B. E. degree in Physics from Fujian Normal University in 2001 and PhD degree in Optics from East China Normal University in 2006. His research focuses on ultrafast optical imaging, including compressed ultrafast photography and nonlinear optical microscopic imaging. He has published over 120 journal papers, including Optica, JPCL, PRApplied, PR, PCCP, APL, JCP and PRA.

Photocurrent and THz emission enhancement in several semiconductors have been observed by femtosecond laser surface nanostructuring. The ultrashort laser pulses induced subwavelength periodic ripples are responsible for the enhancement of absorption, photoconductivity and THz emission. Furthermore, the refractive index anisotropy at THz range is observed in femtosecond laser pulses ablated GaAs semiconguctor.

Dr. Quan-Zhong Zhao received his B.S. & M.S. degrees from Northwestern Polytechnical University, China in 1997 and 2000, respectively. He obtained his Ph.D. in Optical Engineering from Chinese Academy of Sciences, China in 2003. He worked as a postdoctoral researcher in Max-Planck Institute for the Science of Light, Germany, from 2005 to 2009, and he became a full professor in Shanghai Institute of Optics and Fine Mechanics, CAS in 2009. His research interest includes laser-based micro-/nanoprocessing, structuring of versatile materials, functional photonic materials and devices, physics of ultrashort pulsed laser interaction with matter, and fundamental research with potential commercialization. He has authored and co-authored two book chapters and more than 100 journal papers and 30 conference papers.