Emergence of space-division multiplexing for telecom systems has led to a renewed interest in studying the nonlinear phenomena occurring inside multimode and multicore fibers. I review recent progress in this exciting research area and focus on both the step-index and graded-index fibers. Topics covered include not only fundamental issues, such as modulation instability, spatiotemporal solitons, and intermodal four-wave mixing and Raman scattering, but also practically relevant effects such as spatial beam cleanup and supercontinuum generation.

Prof. Govind P. Agrawal is an expert on nonlinear optics, silicon photonics, and optical communications. After holding positions at Ecole Polytechnique, France, City University of New York, and AT&T Bell Laboratories, Agrawal joined in 1989 the faculty of University of Rochester, where he is currently James C. Wyant Professor of Optics. He is an author or coauthor of more than 450 research papers, and eight books. His books on Nonlinear Fiber Optics (6th ed., 2019) and Fiber-Optic Communication Systems (5th ed., 2021) are used worldwide for research and teaching. From January 2014 to December 2019, Agrawal served as the Editor-in-Chief of the OSA journal Advances in Optics and Photonics. Prof. Agrawal is a Fellow of IEEE and OSA and a Life Fellow of the Optical Society of India. In 2012, IEEE Photonics Society honored him with its Quantum Electronics Award. He received in 2013 Riker University Award for Excellence in Graduate Teaching. Agrawal was given the Esther Hoffman Beller Medal in 2015. He was the recipient of two major awards in 2019: Max Born Award of the Optical Society and Quantum Electronics Prize of the European Physics Society.

Ultra-low linewidth stabilized lasers have evolved over the last 40 years and today can generate spectrally pure light with less than 10 mHz linewidth and carrier stability better than 10-17. These lasers play a fundamental role in basic science and precision applications including atomic timekeeping, gravitational wave and dark matter detection, precision spectroscopy, and quantum sensing and computing. Yet these spectrally-pure lasers occupy lab-scale tables and equipment racks, limiting growth in experimental complexity and posing a barrier to transition to commercial applications and environments that require low power, weight and compact size. Translating the performance of stable, spectrally-pure lasers to wafer-scale integrated devices will bring lower cost, size, weight and power with increased environmental robustness. This talk will cover a new generation of photonic integrated ultra-narrow linewidth stabilized lasers that have the potential to bring characteristics of precision spectrally pure lasers to the chip-scale. These lasers are based on stabilization and linewidth reduction techniques using compact and integrated ultra-high Q frequency reference cavities and the linewidth narrowing properties of Brillouin gain. Recent progress that will be described includes devices fabricated in the ultra-low loss silicon nitride CMOS compatible wafer-scale integration platform, including Brillouin lasers operating at 1550 nm, 674 nm and 698 nm, ultra-high Q waveguide resonators with 422 Million and 720 Million quality factor, and fundamental linewidths approaching 100 mHz. Application to atom cooling, atomic clocks, quantum, optical gyroscopes, microwave synthesis and frequency stabilized high capacity coherent fiber communications will be described.

Dr. Blumenthal is a Professor in the Department of ECE at UCSB, Director of the Terabit Optical Ethernet Center and heads the Optical Communications and Photonics Integration group. He is Co-Founder of Packet Photonics Inc. and Calient Networks. He holds 23 patents and has published over 475 papers in the areas of optical communications and optical packet switching, ultra-narrow linewidth integrated lasers, optical gyro sensors, photonic integration integrated circuits, integrated atom cooling photonics, nano-photonics and microwave photonics. He is co-author of Tunable Laser Diodes and Related Optical Sources (New York: IEEE–Wiley, 2005). Dr. Blumenthal is a 2020 recipient of the OSA C. E. K. Mees Medal, a 2017 Fellow of the National Academy of Inventors (NAI), Fellow of the IEEE and Fellow of the Optical Society of America. He is recipient of a Presidential Early Career Award for Scientists and Engineers, a National Science Foundation Young Investigator Award and an Office of Naval Research Young Investigator Program Award. Blumenthal received the Ph.D. degree from the University of Colorado, Boulder (1993), the M.S.E.E. from Columbia University (1988) and the B.S.E.E from the University of Rochester (1981).

Metasurfaces are ultra-thin metamaterials composed by artificial planar meta-atoms arranged in some specific macroscopic orders, which exhibit extraordinary capabilities to control electromagnetic (EM) waves. In this talk, I will give a brief overview on the historical development of metasurfaces, and then present a few representative examples of our group in using metasurfaces to control EM waves. The fascinating effects discussed include photonic spin-Hall effect, generating and dynamically manipulating complex vectorial beams, high-efficiency surface-plasmon excitation and wave-front controls, and controlling the angular dispersions in metasurfaces.

Zhou, Lei received his PhD in Physics from Fudan University, Shanghai, China, in 1997. He then went to Institute for Material Research in Tohoku University (Sendai, Japan) for postdoctoral research. In 2000 - 2004, he was a visiting scholar in Physics Department of the Hong Kong University of Science and Technology. He joined Physics Department of Fudan University in 2004, became a “Xi-De" Chair Professor since 2013, and is now Chair of Physics Department. Lei Zhou got the NSFC "Grant for Outstanding Young Scientist" in 2007 and was entitled "Chang Jiang Scholars Program" Chair Professor in 2009. He was elected as an OSA Fellow in 2019. He won many local and international awards, including OSA Young Scientist Award (2016) and APS Outstanding Referee (2017). He is a funding co-editor-in-chief of the journal Photonics Insights, a managing editor of the journal Nanophotonics, and is an editorial member of Phys. Rev. Mater., and EPJ-AM.

Melanin is the most important pigment in human and acts as a physical barrier to protect keratinocytes and vessels from UV irradiation. Various label-free high resolution imaging technologies had shown their capability for clinical melanin imaging in human skin, but all failed to provide absolute quantitative information in term of mass or mass density. Here we review clinical in vivo microscopical imaging of the melanin distribution in human skin with absolute quantities on mass density using label-free third-harmonic-generation-enhancement-ratio (erTHG) microscopy. By adopting the resonant enhancement ratio to deal with the background calibration beacon issue, here we propose to retrieve the erTHG parameter in situ and thus recover the absolute quantity of melanin within a sub-femtoliter volume. In vivo clinical studies were conducted to compare the absolute quantitative measure obtained by erTHG with those obtained by diffuse reflectance spectroscopy with excellent agreement found. This quantitative imaging tool was further applied for treatment assessment of Asian volunteers with solar lentigines on face. Abnormal melanosome dispersion in diseased cytosols were observed for the first time and treatment does not heal this abnormality. Based on our findings, we conclude the high potential of slide-free label-free erTHG microscopy for absolutely-quantitative melanin imaging in vivo with a subfemtoliter 3D spatial resolution in human skin.

Chi-Kuang Sun is a Life Distinguished Professor in the College of Electrical Engineering and Computer Science (EECS) and the College of Medicine at Taiwan University. He received his S.B. in Electrical Engineering from Taiwan University in 1987, and S.M. and Ph.D. in Applied Physics from Harvard University in 1990 and 1995 respectively. He was an Assistant Researcher in the NSF Center for Quantized Electronics Structures (QUEST) at UCSB between 1995 and 1996. He joined the Taiwan University faculty in 1996 and is currently the Life Distinguished Professor of Electrical Engineering and Photonics at Taiwan University. He served as Chairman of the Photonics Program, Ministry of Science and Technology, Taiwan and was Deputy Dean of the EECS College, Taiwan University. He is the founder and a chief investigator of the Molecular Imaging Center, one of the university-level excellence centers at Taiwan University. Chi-Kuang Sun’s research involves optical molecular imaging, nonlinear microscopy, ultrafast phenomena, nano-ultrasonics, THz health care, advanced femtosecond laser technologies, and applications in virtual biopsy diagnosis, treatment and therapy assessment, surgical guidance, wearable monitoring device, neural science, virus epidemic control, paleontology, interfacial water imaging, and boson peak studies. He leads the advancement and clinical applications of third harmonic generation microscopy for noninvasive differential diagnosis of skin lesions. He is a pioneer for the development of dielectric THz fibers and THz-fiber-based imaging systems, including THz fiber-endoscope, THz near-field microscope, and THz mammography for noninvasive breast cancer and blood examination. He proposes and demonstrates the generation and detection of femtosecond acoustic pulses by using piezoelectric nanolayers, combined with the slow sound velocity and high temporal resolution, for noninvasive atomic-level resolution ultrasound imaging. Chi-Kuang Sun is a Fellow of OSA, IEEE, SPIE, and RMS (London).

Quantum information science and technology enables informational secure quantum cryptography (quantum communication). This presentation will highlight a few of our progress towards the ultimate goal of global quantum communication. We have established a trustful-relay based Backbone connecting Beijing to Shanghai passing through Jinan and Hefei, four metropolitan networks, over 2000-km fiber links. Currently real-world applications by banks, securities and insurance companies are on trial. Another complementing route is to attain global quantum communication based on satellite. We have spent the past decade in performing systematic ground tests for satellite-based quantum communications. Our efforts finally ensure a successful launch of the Micius satellite. Three major scientific missions have been finished. Future Prospects include building a global quantum communication infrastructure with satellite and fiber networks, enormous spatial resolution and global precise timing information sharing networks with applications for the global quantum communication network, ultra-precise optical clocks in outer space to detect gravitational wave signal with lower frequency, and Bell-test experiment with human-observer at a distance on the order of one light-second.

Yu-Ao Chen has done outstanding research on experimental quantum information and quantum simulation based on manipulation of photons and atoms. He is a Fellow of the Optical Society of America and American Physical Society. In the past years, Yu-Ao Chen together with his colleagues has performed a number of significant experiments in the field. Since 2003, has published 8 papers in Nature, 2 in Science, 20 in Nature Physics/Photonics, 2 in PNAS and 40 in Physical Review Letters/X. Till now, his refereed 102 publications have been cited more than 8500 times (ISI Web of Science), with h-index of 43 and 28 of them have been cited more than 100 times each. His experiments were featured widely in scientific news services like: Nature and Nature journals, Physics World, Physics News Update, Scientific American and so on. He was recognized by many prestigious prizes including the 2013 Fresnel Prize for fundamental aspects from the European Physical Society, the Qiu Shi Outstanding Youth Scholar in China, the 2016 Young Scientist Award for the Commission on Atomic, Molecular and Optical Physics from the International Union of Pure and Applied Physics, 2016 Tan Kah Kee Young Scientist Award in Math and Physics, and the 2019 Xplorer Prize from Tencent Foundation. Meanwhile, since 2013, he was appointed as the Chief Engineer for Quantum Communication Beijing-Shanghai Backbone project, which aiming a quantum secure communication network from Beijing to Shanghai over more than 2000 kilometers. Based on the accomplished Beijing-Shanghai Backbone, currently real-world applications by banks, securities and insurance companies are on trial.