Join us for a one- hour talk from Tingyi Gu, University of Delaware, on June 14th, at 12pm titled:
Embedded meta-atoms in integrated photonics
Abstract – The advancement of nanotechnologies enables powerful control of photons by subwavelength structures. In recent years, rapid advancement of metasurface and metamaterials reveal the potential of nanophotonics in the applications across disciplines, from hyperspectral imaging to mathematical operations. One question emerges as: is metasurfaces’ applications limited in deterministic spatial/spectral information or it can play more powerful roles in machine learning and dealing with uncertainties. In this talk I will review recent works on this track and introduce integrated photonic metasurface components, from miniaturized 4-f system to large-scale deep learning. With lithographically defined inter-layer alignment, we demonstrate diffractive deep optical network on silicon photonic platform, towards broadband spatial pattern classification and hyperspectral imaging. The high-throughput vector-by-matrix multiplications is enabled by 103 passive subwavelength phase shifters as weight elements. The integrated metasystem performs analogue optical computing tasks, from simple fourier transformation [1] to complicated image classification [2]. In addition, the symmetric of those embedded meta-atoms control the non-Hermitian Hamiltonian of the integrated photonic system and drive the system towards ‘exceptional point’. This presentation illustrates the design principle of the foundry compatible metasystem, and its implementation of the non- Hermitian resonators, low loss photonic mode converters, differentiators, and hyperspectral image classifiers. Active control strategies will also be covered, by utilizing 2D materials [3] and phase change materials [4].
Bio –Tingyi Gu’s research focuses on integrated photonic devices, developing optical components with new materials for optical communication and sensing applications. She investigates the physics of silicon and chalcogenide-based hybrid nanophotonic devices, and characterizes their potential for large-scale integration, high speed on-chip signal processing and sensing applications. Her work studies nonconventional photonic and electronic properties of nanostructured materials built by different integration techniques and aims to achieve a good understanding of the nanostructured materials photonic functionalities and build a scalable integrated photonic system. She joined the ECE faculty of the University of Delaware in the fall of 2016. She received a B.S. with honors in electrical engineering from Shanghai Jiao Tong University, and M.S. and Ph.D. degrees in electrical engineering from Columbia University. At Bell labs, she worked on silicon photonic network-on-chip systems. She completed postdoctoral research in the Large-Scale Integrated Photonics research group at Hewlett Packard Labs in Palo Alto, CA, studying large-scale nonlinear photonic circuits. She also completed postdoctoral work at Princeton University as a PRISM fellow, studying solution processed chalcogenide materials.
References:
[1] Z. Wang, T. Li, A. Soman, D. Mao, T. Kananen, and T. Gu, On-chip wavefront shaping with
dielectric metasurface. Nature Communications, 10(1), 1-7 (2019).
[2] Z. Wang, L. Chang, F. Wang, T. Li and T. Gu, Integrated photonic metasystem for image classifications at
telecommunication wavelength, Nature Communications (2022)
[3] T. Li, et al Spatially controlled electrostatic doping in graphene p-i-n junction for hybrid silicon photodiode,
npj 2D Materials and Applications 2, 36 (2018)
[4] T. Li, et al, Structural phase transitions in layered materials for integrated photonic memory, Advanced
Materials (2022)
This event will take place in the ASRC auditorium, and be broadcast via Zoom.
Meeting ID: 886 3529 7758
Passcode: 138259
For more information about this hybrid event, please contact:
Leah Abraha
Photonics Initiative