Abstract:Nanophotonic devices can enable unprecedented control over the flow of light, and they hold a great potential for both fundamental studies and next-generation quantum and classical computers, low-power optoelectronics, and free-space applications. In this talk, I will provide an overview of our recent efforts to engineer free-space and integrated photonic systems to enable advanced manipulation of classical and quantum light. In particular, I will describe several approaches to achieve functionalities such as light isolation and trapping, highly dispersive reflectors for augmented reality displays, and analog computation.
I will first focus on our recent works on nonlinearity-based nonreciprocity, a route for magnet-free nonreciprocity that is particularly appealing due to its bias-free operation and ease of fabrication. I will describe the fundamental physics underlying these phenomena, its drawbacks and opportunities for wave engineering, and then discuss our experimental results in silicon photonics and radiofrequency circuits. I will further discuss how combining quantum or classical nonlinearities with peculiar electromagnetic states, such as bound states in the continuum (BICs), can lead to on-demand radiation trapping and release and nonlinear control of the quality factor. I will show how we implemented these effects in vastly different wave-like frameworks, such as single-photon BICs in coupled cavity-atom systems and RF circuits loaded with nonlinear elements.
In the second part of my talk, the focus will shift from integrated systems to free-space metasurfaces – planarized, patterned devices with thickness smaller than or comparable to the operational wavelength. I will discuss how local and nonlocal all-dielectric metasurfaces can be used to achieve different functionalities in the visible and near-infrared, such as focusing, tailored angle- and frequency-dependent mirrors for AR/VR applications, and analog computation.
I will conclude my talk by providing an outlook on promising future research directions, such as combining free-space metasurfaces with nonlinearities and time-modulation to create and manipulate quantum states.
Bio: Michele Cotrufo is a Postdoctoral Research Fellow at the Photonics Initiative at the CUNY Advanced Science Research Center, in New York City. He received a BS degree and a MS degree in Physics from University of Bari, Italy (2010) and University of Padova, Italy (2012), respectively. He then joined the Department of Applied Physics at the Eindhoven University of Technology, Netherlands, as a doctoral student, where he investigated novel light-matter interactions in nanophotonics and hybrid optomechanical systems. After graduating in 2017, he performed postdoctoral research at the University of Texas at Austin.
He is the co-author of over 25 peer-reviewed journal papers. His current research interests span over a broad range of areas, including nonlinear phenomena in classical and quantum electromagnetic systems, nonreciprocal wave propagation, spontaneous emission control with plasmonic and dielectric metamaterials, and optical metasurfaces. In 2018, he was awarded a two-year Rubicon fellowship from the Dutch Research Council (NWO).