清(qing)華大(da)學(xué)材(cai)料科(ke)學(xué)與工(gong)程(cheng)研究院《材(cai)料科(ke)學(xué)論壇》學(xué)術(shù)報告

報告時間：2026年(nian)1月21日(ri)下午14:00-17:00

報告人(ren)：仇成(cheng)偉（新(xin)加(jia)坡國(guo)立大(da)學(xué)）

報告地點：清(qing)華大(da)學(xué)逸夫技(ji)術(shù)科(ke)學(xué)樓A205學(xué)術(shù)報告廳

邀請(qing)人(ren)：周濟院士

報告題目(mu)：Metasurface Photodetectors with and without Machine Learning

報告簡介：

In this talk, we will report a series of metasurface-mediated detectors. Non-centrosymmetric metallic nanoantennas are deployed to break the symmetry of local electromagnetic field and induce directional flow of hot carriers in graphene, leading to large unbalanced mid-IR photoresponse at room temperature without external bias. We demonstrate zero-bias uncooled mid-infrared photodetectors with three orders higher responsivity than conventional bulk photovoltaic effect (BPVE) and a noise equivalent power of 0.12 nW Hz−1/2. We further establish a scheme to realize configurable polarity transition by exploiting the vectorial and non-local photoresponse in hybrid metasurface of nanoantennas and graphene. By tuning the orientation of nanoantennas, polarization ratio (PR) values vary from positive (unipolar regime) to negative (bipolar regime), covering all possible numbers (1 → ∞/−∞ → −1). Polarization-angle perturbation down to 0.03° Hz−1/2 in the mid-infrared range is demonstrated. We particularly show how machine learning could enable high-dimensional detection. Also, we counter-intuitively demonstrate what one could excel without machine learning.

報告人(ren)簡介：

Cheng-Wei Qiu is Provost’s Chair Professor in National University of Singapore. He is the recipient of President’s Science Award 2023, the highest science distinction in Singapore. He was elected Fellow of Academy of Engineering Singapore, and Fellow of ASEAN Academy of Engineering and Technology. He is Fellow of APS, Optica, SPIE and The Electromagnetics Academy, US. He is Foreign Fellow of Chinese Optical Society. He is well known for his research in structured light and interfaces. He has published over 600 peer-reviewed journal papers, with H-index of 141. He was the recipient of MIT TR35@Singapore Award in 2012, Young Scientist Award by Singapore National Academy of Science in 2013, Engineering Researcher Award 2021 in NUS, World Scientific Medal 2021 by Institute of Physics, Singapore, Achievement in Asia Award (Robert T. Poe Prize) by International Organization of Chinese Physicists and Astronomers in 2022, Miller Visiting Professorship in UC Berkeley in 2025, etc. He was Highly Cited Researchers since 2019 by Web of Science. As an overseas partner, he has been awarded China’s Top 10 Optical Breakthroughs for 6 times (2019, 2020, 2021(one in Fundamental Research, and one in Applied Research), 2023, 2025). He has been serving in Associate Editor for various journals such as JOSA B, PhotoniX, Photonics Research, and Editor-in-Chief for eLight. He also serves in Editorial Advisory Board for Laser and Photonics Review, Advanced Optical Materials, and ACS Photonics.