Perfect secrecy cryptography in photonic chips

We are very happy to share our new paper where we demonstrate that it is possible to create a perfect secrecy cryptographic protocol in classical channels. The system uses time varying integrated chips based on silicon on insulator technology and implements a working version of the One Time Pad protocol. The work was the result of the collaboration between our group, King Abdullah University of Science and Technology (KAUST) and the Center for Unconventional Processes of Sciences (CUP Sciences). You can access here the press release from the University of St Andrews.  

The Nonlinear Optical Memory Effect

Light propagating in random media produces characteristic speckle patterns, which remain correlated for small perturbations of the parameters of the incoming beam, including e.g. its angle and position. This behaviour is known as memory effect. In a paper published in Optics Letters, fruit of the collaboration of our group with Dr Tom Vettenburg (University of Dundee) and Prof. Claudio Conti (CNR, Italy), we generalise the memory effect to the case of light propagating in random nonlinear media. In particular, in a series of pump-probe experiments, we quantify the nonlinear memory effect produced by the opto-thermal response of silica aerogel. In this work, the memory effect… Read More »The Nonlinear Optical Memory Effect

Flexible Patches for mm-Wave Holography

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In a paper, published in Applied Physics Letters, we present a flexible holographic metasurface operating in the mm-wave range. The implementation of this metasurface is a three-layer structure using c-rings to encode the hologram and is implemented in both rigid and flexible designs. Furthermore, we present simulations and experimental results of the resultant holographic images. This work is of practical relevance for retrofitting existing mm-wave equipment for applications related to antennas (e.g. for 5G) and electromagnetic shielding.

Perturbation of Transmission Matrices in Nonlinear Random Media

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In this paper, published in Annalen der Physik, we present the direct measurement of the nonlinear transmission matrix of complex materials, exploiting the strong optothermal nonlinearity of scattering silica aerogel. It is shown that the dephasing effects due to nonlinearity are both controllable and reversible, opening the road to applications based on the nonlinear response of random media  

Patterning Multicolor Hybrid Perovskite Films via Top-Down Lithography

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In this paper, published in ACS Nano, we present a platform for lithographically defining micron-sized features with flat tops in lead-haldide perovskites. Our method uses standard resists at low temperatures. Furthermore, we expand this platform to produce arrays of multi-colour pixels for commercial perovskite LED display applications.

Three new Doctors! Congratulation to James, Adam and Xin

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In a remarkable display of timing, James Burch, Adam Fleming, and Xin Li have all passed their PhD Vivas within one week of each other! As is tradition, all three were soaked at the location of the now paved over Physics and Astronomy Pond. We wish all three the very best in their future careers, which include Patent Law, Systems Engineering, and Mobile Technology Design and Fabrication. James Burch, for a thesis entitled: Flexible Holographic Metasurfaces Adam Fleming, for a thesis entitled: Linear and Nonlinear Optical Properties of Silica Aerogel Xin Li, for a thesis entitled: Epsilon-Near-Zero Metamaterials for Optoelectronic Applications

Conformable optical coatings with epsilon near zero response

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In this paper, published in APL Photonics, we design and experimentally demonstrate an optical free-standing and low-loss epsilon-near-zero (ENZ) metamaterial which shows a vanishing effective permittivity at the visible range. We fabricate the flexible ENZ membrane using the sacrificial layer-assisted method by stacking polymer (SU-8) and silver nano-layers. The obtained membranes do not show any sign of degradation even after several thousand bending cycles (BCs). Additionally, we demonstrate that our ENZ material can conform to targets with a radius of curvature of a few microns. This material permits to coat any substrate or device with a tailored made “photonic skin”, decoupling the fabrication requirements from… Read More »Conformable optical coatings with epsilon near zero response

ERC grant: AMPHIBIANS

We are excited to announce the beginning of Dr Di Falco’s ERC consolidator grant AMPHIBIANS.  The project aims to introduce a new biophotonic platform based on the all optical manipulation of flexible photonic metasurfaces. These artificial two-dimensional materials have virtually arbitrary photonic responses and have an intrinsic exceptional mechanical stability. This cross-disciplinary project, bridging photonics, material sciences and biology, will enable the adoption of the most modern and advanced photonic designs in microfluidic environments, with transformative benefits for microscopy and biophotonic applications at the interface of molecular and cell biology. Please visit our job openings page for an update list of available positions.  

We’re recruiting    

The Synthetic Optics groups is recruiting a postdoc to work on the ERC grant AMPHIBIANS. The Synthetic Optics group is recruiting a postdoc researcher to work on the ERC grant AMPHIBIANS. The Research Fellow will be required to design and fabricate photonic metasurfaces for optomechanical and biophotonics applications. The applicant should have demonstrated experience in the design or the fabrication of photonic metasurfaces, preferably in the visible range. A strong candidate will also have demonstrated or clear interest in acquiring expertise on optomechanical and/or biophotonics applications. It is expected that the successful applicant for the advertised position will take these ideas further. The initial contract is… Read More »We’re recruiting    

Integration of sub-micron semiconductor lasers in living cells

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In a paper published in Nature Communications, we report on the integration of sub-micron semiconductor lasers in living cells. In this work, fruit of the collaboration with Malte Gather and his group at the University of St Andrews, we demonstrate that lasers with dimensions much smaller than that of many cell nuclei can be used to tag individual cells and sense their environment. This research paves the way for a new bio-photonics platform that will provide new insight into cell biology, including research in immune cells, neutrons and cancer cells. A. H. Fikouras, M. Schubert, M. Karl, J. D. Kumar, S. J. Powis, A. Di… Read More »Integration of sub-micron semiconductor lasers in living cells