"Science Chinese" sealed the second character - Zhan Qiwen
From the 20th century to the present, from classical mechanics to quantum theory, the concept of space and time in physics has more than once caused revolutionary changes. And when time and space are really fused together to form a new state of photon motion, what kind of changes will be brought to science and technology?
In 2020, a research result from the Nanophotonics Innovation Team of the School of Optoelectronic Information and Computer Engineering of the University of Shanghai for Science and Technology was published in the world's top optical journal Nature-Photonics, and was successfully selected as one of the 30 Major Advances in Global Optics in 2020 and the Top Ten Advances in Chinese Optics in 2020 by the Optical Society of America (OSA). In the field of angular momentum of photon orbits, this research creatively "combines the ultrafast pulsed light time field regulation and the space light field regulation field into one", showing for the first time from theory to experiment a new type of light field with spatio-temporal vortex phase and carrying the angular momentum of photon transverse orbit, creating a new photon orbital angular momentum freedom.
As the person in charge of the project, Zhan Qiwen, professor of the School of Optoelectronic Information and Computer Engineering of the University of Shanghai for Science and Technology and chief scientist of the nanophotonics innovation team, devoted himself to the innovative research of light field regulation and its interaction with micro-nano structures, and finally blew up a photon "hurricane" in the field of optics, achieving a breakthrough of "from 0 to 1".
How can you endure loneliness by dealing with light particles in the lab for decades? Zhan Qiwen's answer was unexpected: do what you are interested in, not lonely.
Qiyi Zhan (second from left) receives the SPIE Fellow certificate at the SPIE Photonics West conference
<h1 class="pgc-h-arrow-right" > drive innovation upwards, "sculpting time" at the micro-nano scale</h1>
In recent years, nanostructures, metamaterials, etc. have continuously refreshed people's understanding of the spatial structure of matter, and the "light field" as a description of the direction and distribution of light in space has gradually entered people's field of vision. The regulation of the light field is like the spatial range of a painting, different positions can see different light intensities, different colors of light. Zhan Qiwen's main research area is the regulation of light fields and its interaction with micro-nano structures, that is, the temporal and spatial arrangement of light structures from the micro-nano scale. "So we sometimes joke that when we do light field regulation research, we are 'sculpting time.'"
The regulation of the light field is not as easy as imagined, the corresponding light field of different structures is different, and to get the optimal match, it is necessary to realize the free regulation of the light field. When the degree of freedom is large enough, there is an optimal solution to achieve super-resolution imaging and other purposes in specific applications. Light field regulation can intersect with different fields of discipline and solve one specific scientific problem after another.
Zhan Qiwen graduated from the University of Science and Technology of China in 1996 with a bachelor's degree in physics, and then went to the United States to study, and received a doctorate degree in electrical engineering from the University of Minnesota in 2002. In the same year, he was appointed as an assistant professor and tenured associate professor at the University of Dayton, and was appointed as a tenured professor in 2012, focusing on light field regulation and its interaction with micro-nano structures, nanophhotonics, biophotonics, super-resolution imaging and nanostructure characterization. During his tenure in the United States, he also founded the University of Dayton's Laboratory of Nanoelectronic Optics and the University of Dayton's Fraunhofer Center as director.
In the United States for more than ten years, Zhan Qiwen has found that the structure of nanomaterials has a natural strong correlation and role in the polarization state of nanomaterials through the study of the application of complex light fields in the structural characterization of nanomaterials and the development of related instruments, which can be used as an optical nondestructive analysis and characterization means to explore new nanomaterials. These non-traditional optical polarization states and their focused light fields have a special role in optical tweezers, which can achieve stable manipulation of nanoparticles such as metals, low refractive index media (such as bubbles), anisotropic materials and even magnetic materials. From 2002 to 2003, he creatively proposed and realized a series of simple technical methods for the reflection, steering and rotation of vector light fields with simple optics, and invented optical instruments such as high-resolution high-precision scanning microellipse for the first time using the spatial symmetry of beam polarization.
In 2007, a problem with how to do light field imaging detection in semiconductor devices came to the door. Originally, due to the possible stress of the structure in the semiconductor chip, it may lead to a significantly shortened life cycle of the chip, or even a serious failure. At the time, optical techniques in the application could not image the possible stress distribution. Zhan Qiwen's research results on complex light fields just perfectly solve this problem. By focusing on the complex light field structure similar to the wheels of a bicycle, the distribution of stress in the semiconductor chip can be seen at a very high resolution.
Zhan Qiwen led the laboratory team to continue to carry out in-depth research, and successfully applied the corresponding technologies to the detection of semiconductor devices, optical waveguides, biological samples, tiny optical devices and ultra-thin semiconductor dielectric films, and to achieve optical imaging with superdiractation limit. Using the optical antenna he proposed under the stimulation of the optimal surface plasma, he and his team also developed a new nano-Raman spectroscopic imaging technology, and explored its application in the study of ultra-high resolution light field imaging of next-generation integrated circuits and the structural integrity of nanomaterials, and obtained 4 international patents, which were promoted by high-tech companies such as CyberOptics in the United States and HSEB GmbH in Germany.
"Innovation often stems from two driving forces: one is the pull generated by the application demand, and the other is the support generated by the breakthrough of basic research. When the two sides meet together, a solution is created. Zhan Qiwen said. After that, he systematically proposed the theory of spatial polarization pattern matching and successfully applied it to optimize surface plasma focusing, and experimentally verified that the use of radial polarized beams for surface plasma excitation produces a unique fleeting Bessel light field. This concept has also been further extended to other resonance structures such as photonic crystals, etc., which can obtain optimized local light fields and field enhancement effects by matching the spatial polarization state of the excitation beam with the corresponding micro-nano structure. Due to the broad application prospects in nanoscale optical imaging and detection, Zhan Qiyiwen cooperated with the University of Texas to further combine the local field enhancement effect caused by spatial polarization mode matching with new photoelectric materials and photonic crystal slow optical waveguides, and designed and demonstrated an ultra-high sensitivity rf electromagnetic field optical sensor.
"Bold innovation" does not stop there, Zhan Qiwen's research results in complex light fields cover the mathematical and physical description of vector beams, experimental generation and manipulation, transmission, focusing characteristics and practical applications of these properties. He has also been involved in pioneering work in the emerging subject area of "Light Field Regulation" and has contributed to its rapid development, and was invited to write a review of the field for the inaugural issue of the American Optical Society journal Advanceds in Optics and Photonics. Since its publication, the article has long been one of the most downloaded and highly cited articles in the journal, and has been listed by the Scientific Citation Index (SCI) as one of the highest cited articles in the field of optics in the past 10 years.
As a special invited speaker, he took a group photo with invited experts from China, the United States, Canada, Japan, Germany, South Africa and other countries at the Structured Light International Special Seminar
< h1 class= "pgc-h-arrow-right" > discovered "photon hurricane" and achieved a breakthrough "from 0 to 1"</h1>
Strengthening basic research, educating and cultivating innovative talents, focusing on improving the original innovation ability, and striving to achieve more breakthroughs from "0 to 1" are the core requirements and means for China to implement the innovation-driven development strategy, improve the new national system for key core technology research, and face the world's scientific and technological frontiers and face the major needs of the country. In the field of photonic science, many scientists have devoted their lives to the research of photonic communication fields such as space light fields or ultrafast pulsed light, and to combine time and space to truly "sculpt time", but no one has done it. Since graduating with his doctorate, Zhan Qiwen has planted the seeds of this dream.
After 20 years, he has not forgotten this "original intention". It wasn't until 2020, after many years of working back home, that dream finally came true. For the first time, he and his team demonstrated a new type of light field with a spatio-temporal vortex phase and carrying the angular momentum of the transverse orbit of photons, creating a new degree of freedom of angular momentum of photon orbits.
This is a real "0 to 1" breakthrough. For a long time, due to its important applications in micro-nano particle manipulation, super-resolution optical microscopy, super-resolution laser processing, ultra-high-flux optical interconnection, high-dimensional quantum secure communication and information processing, the orbital angular momentum of photons has attracted a lot of global research interest in recent years, and is an international hot scientific research problem. Optical information science has also developed rapidly thanks to the continuous breakthrough of ultrafast pulsed light.
Zhan Qiwen cites the concept of meteorology as a metaphor, when the tornado's air flow rotates, from top to bottom to the ground, constantly produces a state of "axial rotation", and the orbital angular momentum of photons is similar to this state. If the trajectory of optical angular momentum that has been discovered is a "tornado," his and his team's latest discovery is to form a hurricane of photons that resemble fast-moving ones.
"At that time, we were thinking that in meteorology, in addition to the vortex of the tornado, there is also a vortex state like a typhoon. Since we have tornadoes in optical research, is there a way for typhoons to move in this state? And if we want to do it, we have to 'stir' the time in. "The innovation of basic scientific research often lies in breaking through the stereotypes of thinking and dismantling the fences of thinking." With bold imagination, there must also be strong execution. Driven by the dream, Zhan Qiwen and his team overcame the obstacle of thinking and faced the irreconcilable contradictions in this study in two different fields of light field space regulation and ultrafast pulsed light. From 2018 to 2020, in just two years, they realized this breakthrough concept in the field of optical regulation, providing a new means of using light to identify matters and providing a wider channel for information transmission.
"At the beginning, we were curious to see if we could shoot light from the ultrafast pulse platform to the space light field control platform, but we found that this was not a simple 1+1, so we tried to integrate the experimental elements and combine the two non-intermingled fields on one experimental table." Using more than 20 years of accumulated scientific research experience, Zhan Qiwen led the team to creatively use the Fourier transform of "space frequency - frequency surface to space - time plane" to successfully generate an ultrashort pulse optical wave packet carrying the angular momentum of the transverse photon orbit, this new type of light wave packet In the rapid forward transmission of photon energy, the photon energy flow rotates around a transverse axis that moves with the wave packet, thus forming a photon "hurricane". This discovery has important potential research and application value in the fields of optical communication, optical information processing, quantum optics, particle manipulation, new energy, and relativistic space physics.
The method used is the principle that everyone in the field of optics understands, and the device formed is easy to popularize, but Zhan Qiwen and the team are the first to do it ahead of the world, which ultimately lies in "thinking one step more" than others. Breakthroughs were made quickly after the project began, and even after the protocol was finalized, it took only two months to verify the conclusions, which surprised Zhan Qiwen and the team. They repeatedly analyzed the data and finally determined that the state of the ultra-pulsed optical wave packet did occur, which was much shorter than the time originally planned. Nevertheless, the production of this breakthrough result is not accidental, even the result of "ten years of grinding a sword", the seed of the dream has borne the most fruitful fruit after years of innovation in scientific research.
The research results of Zhan Qiwen and his team have been recognized by the world photonic science community, and published in the world's top optical journal "Nature -Photonics", and successfully selected as one of the 30 major optical advances in the world in 2020. But they didn't stop studying. The release of new theories will inevitably trigger more fierce competition in the field of application, and as a "nest builder", we must also walk in the front and lead the tide of innovation in this field. In 2020, the research team was supported by the key project of the National Natural Science Foundation of China "Major Research Program on Physics and Application of New Light Field Regulation", and will further carry out systematic and in-depth research in this field.
In scientific research, is "from 0 to 1" more important, or is "from 1 to 100" more important? This may be an incomparable problem. But from 0 to 1, it means that this research has a certain randomness, there are unlimited possibilities, is a process of free exploration, even if it is impossible to predict what application problems can be solved, but as long as it is broken, it may bring revolutionary changes to a certain field; similarly, from 1 to 100, it will continue to witness the innovation of basic theories for human scientific and technological life to bring a huge impetus, which may be the charm of scientific research, but also the driving force for scientific researchers to go all out and pursue excellence.
As Associate Editor of Optica, he took a group photo with top journal editors workshops such as Nature, APL Photonics, ACS Photonics, Light: Science and Applications, Nature Physics, Nature Communications, Advanced Optical Materials, Nanophotonics, and other top journals.
<h1 class="pgc-h-arrow-right" > pays attention to the "blending of theory and reality" and leads the team to the international stage</h1>
Although he has graduated from the university for more than 20 years, Zhan Qiwen still firmly remembers the motto of his alma mater, the University of Science and Technology of China, "Red College, Fusion of Science and Reality", not only to have the spirit of innovation and ability, the combination of theory and practice, but also to think about how to repay the motherland and contribute to society, these 8 words have also become the motto that affects Zhan Qiwen's life. At that time, although the rapid development of domestic optics, but still greatly restricted, when choosing a profession, Zhan Qiwen did not hesitate to choose this field as his future development direction. The 5 years of study and life at the University of Science and Technology of China also laid a solid foundation for his later scientific research path.
At the end of the 1990s, the domestic Internet infrastructure began to become popular, and the exchange of information in the field of scientific research was still relatively closed compared with developed countries such as the United States. Zhan Qiwen chose to study at the University of Minnesota in the United States in order to go to the forefront of the development of optical disciplines and exchange and study with the world's top scientists. Continuous innovation in complex light fields has gradually established himself in the field of optical science in the United States. After graduating with his doctorate, he has maintained close cooperation and exchanges with domestic universities and scientific research units such as the University of Science and Technology of China, and promoted the international conference on nanophotonics to be held in China, so that Chinese and foreign scientists can achieve "zero distance" exchanges. After years of cultivation, the International Conference on Nanophotonics has formed a scale of 500 participants. More than two years ago, Zhan Qiwen eliminated the obstacles to returning to China and chose to return to the University of Shanghai for Science and Technology to teach, combining his research advantages in basic theory with the advantages of engineering application disciplines of the University of Shanghai for Science and Technology, and committed to solving key problems in more fields.
Since returning to China, Zhan Qiwen has devoted most of his time to scientific research, and although he is very busy, he is willing to do so- research work itself is his interest. Under the leadership of Zhan Qiwen, the University of Shanghai for Science and Technology established an innovation team for nanophotonics, which received key support from the Shanghai Municipal Education Commission. As the chief scientist, he hopes to truly cultivate the nanophotonic innovation team into a scientific research team with greater international influence.
Under the leadership of Zhan Qiwen, the team is working on the application of the space-time regulation of the light field, such as how to control the "chirality" of the light field, once a breakthrough is made, it will be possible to distinguish the different characteristics of the substance with the help of the "chirality" of the light field. In Zhan Qiwen's view, the "chirality" theory of light field can be applied to pharmaceuticals, many molecules in drugs have different chiral properties, they have the same molecular formula, but the structure of spatial arrangement is completely different, just like the left hand and right hand in mirror reflection. "In the molecules of chemicals, perhaps a certain chiral is an active ingredient, and the opposite chiral is an invalid ingredient or even toxic, and we need to distinguish between different chirals. With the help of light field regulation, it is possible for us to distinguish and screen whether the molecule is left-handed or right-handed at the scale of tens of nanometers. Zhan Qiwen said.
Today, the number of researchers in the nanophhotonics innovation team has reached 28, most of whom are post-80s or even post-90s. For the young talents in the team, Zhan Qiwen hopes that each of them will gradually have their own research field and form their own unique scientific research "brand". As a mentor, he is committed to teaching different students according to their aptitudes, inspiring students to understand their strengths and strengths, and stimulating their interests. In more than a decade abroad, he has trained more than 20 doctoral students in the field of photonics.
For the future planning, Zhan Qiwen said: "I hope that through solid efforts, in three or five years, the overall team can be recognized internationally, produce more research results, and be applied in more fields." For many people who say that "to do scientific research to endure loneliness", Zhan Qiwen has a different answer, "Not lonely, my research work is something that I am interested in, it is as simple as that."
Zhan Qiwen is a professor at the University of Shanghai for Science and Technology and the chief scientist of the Nanophotons Innovation Team. B.S. in Physics, University of Science and Technology of China (1996) and Ph.D. in Electrical Engineering, University of Minnesota ,USA (2002). In 2002, he was appointed as an assistant professor (2002), tenured associate professor (2008), tenured professor (2012), and founded the University of Dayton Nanoelectronic Optics Laboratory and the Fraunhofer Center of the University of Dayton as director.
His research interests include light field regulation and its interaction with micro-nano structures, nanophotonics, biophotonics, super-resolution imaging, and nanostructure characterization. Associate Editor of Optics Society Journal Optica, Associate Editor of PhotoniX Journal of Optical Engineering of China, Editorial Board Member of Nature Publishing Group Scientific Reports, Editorial Board Member of Natural-Springer Journal of Nondestructive Evaluation, Director of Optical Society of China. He was elected a Fellow of the International Optoelectronic Society (SPIE) and fellow of the American Optical Society (OSA) in 2012 and 2013. He has published more than 160 papers in important international academic journals such as Advanceds in Optics and Photonics and Nature Photonics, cited more than 10,000 times (the highest single citation > 2,200 times), published 1 monograph, 9 chapters of monographs, obtained 5 patents from the United States and internationally, and carried out industrialization development in the United States, Germany and other enterprises for technology transfer such as high-resolution elliptic imaging and near-field Raman.