We study light at the nanoscale, which is nanophotonics, and the coherent interaction of light with complex photonic systems. 

Our main scientific interest is nanophotonics of complex systems. We study metamaterials, which are artificial materials with properties that do not exist in natural materials. In particular we are looking at time-varying metamaterials, whose optical properties vary in time on very fast time-scales, of the order of the light optical cycle. We also investigate unconventional lasers, designed by nanostructured materials, which we exploit as neuromorphic computers, capable to perform calculation during their lasing action. Our main scientific tools are single emitter spectroscopy, lasing microscopy and ultrafast nonlinear microscopy.

Time-varying metamaterials

We want to develop the building blocks of a space-time metasurface for optical waves, based on large and ultrafast modulations of the complex refractive index of indium tin oxide (ITO). Static metasurfaces have been a milestone in how we control light waves by manipulating their phase and amplitude on the wavelength scale. Yet, they are still bounded by Lorentz reciprocity and energy conservation. A dynamical metasurface, whose optical response can be fully controlled at the speed of light through a time-varying refractive index would not be just a powerful technological element, but would also bring about the rich new physics of non-Hermitian and non- time-reversible optics.
Visit also the Centre for Plasmonics and Metamaterials in Imperial College London for more details.

Multiple, disruptive wave-based technologies (acoustic, elastic, radio-frequency, terahertz, and optical) would emerge if the response of the underlying materials could be modulated at will, varying throughout space and time.

META4D will simultaneously explore the fundamental physics of space-time-modulated materials and be the first to demonstrate their potential in real world applications; we will design and test a new generation of 4D (space and time) materials.

ERC-Advanced Light interaction with synthetically moving metamaterials - LUMINOUS, will experimentally investigate synthetic motion to perform analogue computation. The key to this project is our ability to achieve very large, close-to-unity temporal modulations on the timescale of the optical period of light (~fs), together with digital control of millions of spatial degrees of freedom via structured light, therefore enabling programmable synthetic motion. It will establish the experimental platform for programmable motion and use it to control light flow and light generation. Moreover, using synthetically moving metamaterials as space-time operators, I will solve non-separable differential equations, as well as perform analogue simulation of relativistic phenomena.


COMPLEX PHOTONIC NETWORKS for neuromorphic computing

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Complex nanophotonic networks offer a unique approach to light transport and light emission control, by designing a set of distributed single emitters that share information through photonic connections, and that can be remotely addressed: this is what we call random lasing.
They can also be used to design the light modes of an unconventional laser, which is not directional nor monochromatic: a photonic network laser. The complex process behind lasing can also be used a resource for neuromorphic computing.
We are part of a European Training Network - Coral, together with IBM Zurich to study network lasers on chip.

HYPERUNIFORM DISORDERED NETWORKS

Hyperuniform disordered photonic materials are a new class of materials that harness structural disorder and control light transport, emission and absorption in unique ways, beyond the constraints imposed by conventional photonic microcircuit architectures. We are studying the physics and application of hyperuniform disordered nanophotonic structures. As an important application we have shown that light absorption in silicon solar cells can be boosted by hyper uniform topologies.


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Single photon extraction from individual emitters
Nanophotonics and nanoscale optics, which are aimed at coherent control and manipulation of single photons emitted by individual quantum emitters in a nanostructured photonic environment offer a revolutionary new approach to computation and information technology: bits can be carried in the state of light and processed by nanoscopic amount of matter. We are studying the generation of single photons for individual quantum dots coupled to nanostructure and dielectric antennas and their routing to specific distant location. Recently, we have shown that charged excitons in individual quantum dot can be controlled by electrical control, providing boosted and tunable single-photon sources. We have investigated how light emission from 2D-materials can be enhanced by 4 orders of magnitude using nano-antennas.