nanophotonics

Light management in non-Hermitian media

Dr. Waqas Ahmed, Electrical Engineering, King Abdullah University of Science and Technology

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KAUST

Structured media provide the momentum compensation for the scattering of waves. It is well-known that nano-scale modulations of the refractive index may lead to a temporal and spatial control over light propagation. Yet, also engineering the gain and loss profile uncovers analogous shaping effects. However, only the interplay between both the refractive index and gain and loss modulations introduces unidirectionality in light management. Thus, non-Hermitian optics has become one of the most fertile grounds in optics. A generalized Hilbert transform allows tailoring the two quadratures of the complex permittivity to design periodic or disordered non-Hermitian media, holding either global or local unidirectionality following arbitrary vector fields to tailor the flow of light. The method allows restricting the permittivity within realistic values rendering it suitable for applications.

Viability assays of CMOS-compatible materials, device architectures, and emerging device platforms for nano-photonics

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B5 L5 R5209

My research at the University of Toronto involves designing and fabricating CMOS-compatible nano-plasmonic waveguide structures and devices for on-chip communication. By taking advantage of the absence of diffraction limits, strong modal confinement is made possible using plasmonic device architectures, laying the foundations for improved optical processes and photonic circuit integration. All-oxide structures have emerged as promising plasmonic materials that can serve as relatively low carrier density Drude metals and dielectric spacers by their electro-optic tunability and versatility. I demonstrated the facile integration of all-oxide heterointerfaces into metal–insulator–semiconductor (MIS) electro-optic structures. From there, I fabricated MIS devices that incorporated semiconductive oxide layers with oxide dielectric spacers on silicon-on-insulator (SOI) platforms, constituting graded-index coupled hybrid plasmonic waveguide (CHPW) optical modulators.

Yanfen Zhai

Yanfen Zhai is a Postdoctoral Fellow working under the supervision of Professor Atif Shamim at Integrated Microwaves Packaging Antennas and Circuits Technology (IMPACT) Research Group in King Abdullah University of Science and Technology (KAUST). Research Interests Yanfen's research interests include Nano-Photonics and Nanotechnology, Antenna design, integration and miniaturization techniques, On-Chip Mid-Infrared Gas Sensor, On-Chip Ultra - Wideband Optical Switch Matrix (MEMS), and Quantum Single-Photon Source (Nonlinear optics). Patents: 1) Y. Zhai, W. Zhang, and Y. Huang, “A kind of

Chun-Ho Lin

Chun-Ho Lin obtained his Ph.D. in Electrical Engineering from King Abdullah University of Science and Technology (KAUST) under the supervision of Prof. Jr-Hau He in 2018. Lin completed his master’s degree in the Department of Electrical Engineering from the National Taiwan University and began his Ph.D. studies at KAUST in 2014. Research Interest Chun-Ho Lin's research interests include Perovskites, Nanophotonics, Flexible Electronics, Paper device, and 2D Materials.