20th APROPOS (2026)

Professor Xi-Cheng Zhang is a leading figure in terahertz photonics and optics, serving as the Parker Givens Chair at the University of Rochester’s Institute of Optics. Zhang conducted pioneering research in groundbreaking terahertz research during two decades at Rensselaer Polytechnic Institute, where he founded the Center for THz Research and pioneered ultrafast laser-based THz techniques. Zhang’s work advanced free-space terahertz optoelectronics and demonstrated novel uses for ultrafast “T-ray” pulses in imaging and spectroscopy. Since 2012 at Rochester, Professor Zhang’s group has continued to push the frontiers of terahertz science, developing advanced THz sources and detection techniques for spectroscopy and non-destructive imaging. Zhang has earned broad recognition as a Fellow of the AAAS, APS, IEEE, Optica, and SPIE, with major awards such as Optica’s William F. Meggers Award (2012) and the IRMMW-THz Kenneth J. Button Prize (2014) acknowledging pioneering contributions to terahertz science.  

Miriam Serena Vitiello is a senior researcher at the National Research Council of Italy (CNR-NANOTEC, Pisa), internationally recognized for her contributions to terahertz photonics and nanoelectronics. Her research focuses on the development of compact terahertz sources and detectors based on semiconductor and quantum devices, including quantum cascade lasers, as well as hybrid plasmonic architectures. By combining nanofabrication, spectroscopy, and device physics, Vitiello has advanced terahertz technologies relevant to spectroscopy, sensing, and imaging. Her work has been supported by major competitive funding programs, including European Research Council grants, and has helped shape the landscape of modern terahertz science.

Taiichi Otsuji is a leading researcher in terahertz electronics and photonics and a professor at Tohoku University in Japan, known for uniting cutting-edge semiconductor physics with high-frequency photonics. He has developed plasmonic devices that harness electron oscillations in semiconductor heterostructures and graphene to generate and detect terahertz waves, opening new avenues for THz sensing technologies. Otsuji’s breakthroughs include the realisation of tunable terahertz sources using graphene, demonstrating ultrafast phenomena that extend the performance limits of conventional terahertz emitters and detectors. Otsuji’s achievements have earned widespread recognition both in Japan and internationally. He is a Fellow of IEEE, Optica (OSA), and the Japan Society of Applied Physics. 

Willie Padilla is a leading expert in metamaterials and applied physics and a distinguished professor at Duke University. His doctoral research at UC San Diego (Ph.D. 2004) contributed to early experimental breakthroughs in metamaterials – Padilla was part of the team that demonstrated the first negative-index metamaterial, a revolutionary concept enabling artificial “left-handed” optical materials. Padilla has since pioneered a range of dynamic and functional metasurfaces, from actively tunable THz devices to metamaterial absorbers that achieve near-unity absorption under designed operating conditions of incident radiation. Padilla’s innovative approach to imaging led to the creation of single-pixel terahertz cameras using compressive sensing, drastically reducing the detector arrays required for THz imaging. He has received top honors including the U.S. Presidential Early Career Award for Scientists and Engineers in 2009, and is recognised as a Fellow of the Optical Society (Optica) and of IEEE for his contributions to photonics and metamaterials. 

Dr. Shang-Hua Yang stands out in the terahertz research community for bridging theory and application, from fundamental plasmonic photonics to real-world wireless and imaging systems. At National Tsing Hua University, Yang has built a vibrant lab exploring ultrafast electro-optics and THz devices, and he is spearheading Taiwan’s efforts in terahertz technology as director of a dedicated terahertz research centre at NTHU. Yang’s innovations include new schemes for high-speed terahertz wireless links and non-invasive THz imaging, reflecting his group’s ability to push technology boundaries in both communications and sensing. Yang has garnered significant acclaim at a young age: major honours such as the Ta-You Wu Memorial Award (2024) and the NTHU Young Faculty Research Award (2020) highlight the impact of his early-career achievements. Yang, a Senior Member of IEEE and a Member of Optica and SPIE, contributes to the scientific community beyond research by serving on organising and technical program committees for leading optics and electromagnetics conferences. 

Agnieszka Siemion has pushed the frontiers of modern optics into the terahertz realm, crafting a niche where purely photonic phenomena intersect with millimeter-wave science. Prof. Siemion leads cutting-edge experiments at Warsaw University of Technology on THz diffractive optics, creating components like frequency-selective surfaces and multi-focus lenses that unlock new capabilities in the far-infrared spectrum. Siemion’s experimental prowess has yielded novel THz imaging techniques – including systems capable of distinguishing minute differences in tissue composition – which hold promise for non-invasive medical diagnostics and security scanning. She was actively involved with major research initiatives, including a LIDER project on terahertz systems for skin cancer research and an OPUS project investigating terahertz optical MIMO concepts. Beyond research, Siemion is celebrated for outstanding teaching – winning the student-bestowed Golden Chalk Award five times – and has taken on a key leadership role as Vice-Dean for Student Affairs (since 2020), helping foster the next generation of optical physicists. 

Dr Karolis Kazlauskas is a leading figure in the field of organic semiconductor photonics, heading the Organic Optoelectronics Laboratory at Vilnius University’s Institute of Photonics and Nanotechnology. He has made seminal contributions to materials for organic light-emitting devices and stimulated-emission applications, designing novel molecular structures that exhibit efficient fluorescence and improve the operational stability of organic emitters. Kazlauskas’s group is also known for advancing photon upconversion techniques, enabling the conversion of low-energy infrared light into higher-energy visible emissions – an approach that has potential applications in areas like foldable displays and light-emitting fabrics. He has authored numerous highly cited papers in journals such as J. Mater. Chem. C and Adv. Optical Mater. and is frequently invited to present his work, including invited talks at major international workshops and conferences in Japan and elsewhere. Dr Kazlauskas’s contributions have earned him accolades such as the Lithuanian Academy of Sciences’ Young Scientist Fellowship and multiple Vilnius University awards for research excellence, cementing a reputation as a leader in optical materials research.