My field of interest in science!!!!

 I am a Research Fellow of the Italian Institute of Optics (CNR) and Project Leader at the European Laboratory for Non-Linear Spectroscopy (LENS). As natural continuation of my previous work on the optics of ordered and disordered systems, I'm now focusing my research on the fascinating field of optics of engineered-disordered systems, spanning from fractal disorder (Lévy glass) to correlated-disorder media (amorphous photonic material). 

I obtained my Ph.D. (Philosophiae Doctor) at the University of Twente in 2009 after a 4 years work at the FOM Institute AMOLF, which houses the Center for Nanophotonics. I worked in the group NanoOptics led by L. (Kobus) Kuipers with a phase-sensitive time-resolved near-field microscope. Thereafter, I spent two years as postdoctoral fellow in Diederik Wiersma's group at LENS investigating anomalous light transport in disordered systems and its possible applications in photovoltaics. 


  • 15-01-15;
Our manuscript entitled "Optically controlled elastic microcavities" has been accepted by Light: Science and Application. Authors:Assegid Mengistu Flatae, Matteo Burresi, Hao Zeng, Sara Nocentini, Sarah Wiegele, Camilla Parmeggiani, Heinz Kalt, and Diederik Wiersma.
  • 01-01-15;
My manuscript entitled "Device-Level photonics testing" has been published by Nature Photonics. Authors: Matteo Burresi.
  • 31-12-14;
Our Review entitled "Complex Photonic Structures for Light Harvesting" has been accepted by Advance Optical Materials. Authors: Matteo Burresi, Filippo Pratesi, Francesco Riboli, Diederik S. Wiersma.
  • 22-08-2014;
Our manuscript entitled "Walk dimension for light in complex disordered media" has been published by Physical Review A.
Authors: R. Savo, M. Burresi, T. Svensson, Kevin Vynck and Diederik S. Wiersma.

Transport in complex systems is characterized by a fractal dimension—the walk dimension—that indicates the diffusive or anomalous nature of the underlying random walk process. Here we report on the experimental retrieval of this key quantity, using light waves propagating in disordered media. The approach is based on measurements of the time-resolved transmission, in particular on how the lifetime scales with sample size. We show that this allows one to retrieve the walk dimension and apply the concept to samples with varying degree of fractal heterogeneity. In addition, the method provides the first experimental demonstration of anomalous light dynamics in a random medium.

  • 15-08-14;
Our recent work on the Brightness of white beetles has been reviewed by several the magazines: BBC News, the Guardian, Nature World News, MailOnline, Specktrum.
  • 15-08-14;

Our manuscript entitled "Bright-White Beetle Scales Optimise Multiple Scattering of Light" has been published by Scientific Reports. Authors: Matteo Burresi, Lorenzo Cortese, Lorenzo Pattelli, Mathias Kolle, Peter Vukusic, Diederik S. Wiersma, Ullrich Steiner and Silvia Vignolini.

Whiteness arises from diffuse and broadband reflection of light typically achieved through optical scattering in randomly structured media. In contrast to structural colour due to coherent scattering, white appearance generally requires a relatively thick system comprising randomly positioned high refractive-index scattering centres. Here, we show that the exceptionally bright white appearance of Cyphochilus and Lepidiota stigma beetles arises from a remarkably optimised anisotropy of intra-scale chitin networks, which act as a dense scattering media. Using time-resolved measurements, we show that light propagating in the scales of the beetles undergoes pronounced multiple scattering that is associated with the lowest transport mean free path reported to date for low-refractive-index systems. Our light transport investigation unveil high level of optimisation that achieves high-brightness white in a thin low-mass-per-unit-area anisotropic disordered nanostructure.

  • 07-04-14;
Our manuscript entitled "Light transport and localization in two-dimensional correlated disorder" has been published by Physical Review Letters. Authors: Gaurasundar M. Conley, Matteo Burresi, Filippo Pratesi, Kevin Vynck and Diederik S. Wiersma.

Structural correlations in disordered media are known to affect significantly the
propagation of waves. In this Letter, we theoretically investigate the transport and localization of light in 2D photonic structures with short-range correlated disorder. The problem is tackled semianalytically using the Baus-Colot model for the structure factor of correlated media and a modified independent scattering approximation. We find that short-range correlations make it possible to easily tune the transport mean free path by more than a factor of 2 and the related localization length over several orders of magnitude. This trend is confirmed by numerical finite-difference time-domain calculations. This study therefore shows that disorder engineering can offer fine control over light transport and localization in planar geometries, which may open new opportunities in both fundamental and applied photonics research.
  • 21-03-14;
Rai 1 (the main national TV channel) showed a reportage about the scientific activities of LENS. I'm one of the main actors! (look up at the minute 6th);
  • 24-12-13;
Two new manuscripts on anomalous transport in engineered-disordered systems can be found on the arXiv:
  • 26-11-13;
One PhD position inserted in the Erasmus Mundu project is available in the group (application deadline January 31st, 2014, 00:01 GMT ). We are seeking enthusiastic candidates with a solid background in Electromagnetism and Material Science. The candidate will work together with physicists and chemists to realize opto-mechanically controlled photonics devices.
For more information visit the Erasmus Mundu website or contact Matteo Burresi.
  • 26-06-13;
The Proceedings of the first Joint EPS-SIF International School on Energy 2012", of which i was
Scientific Secretary, entitled "New Strategies for Energy Generation, Conversion and Storage" has been published online. Here is the Preface of the Directors of the school (L. Cifarelli, F. Wagner and D.S. Wiersma) and here is my contribution.

  • 23-04-13;
Our manuscript entitled "Disordered photonic structures for light harvesting in solar cells" has been published in a Focus Issue of Optics Express. Authors: Filippo Pratesi, Matteo Burresi, Francesco Riboli, Kevin Vynck and Diederik S. Wiersma.

The effect of periodic and disordered photonic structures on the absorption
efficiency of amorphous and crystalline Silicon thin-film solar cells is investigated numerically. We show that disordered patterns possessing a short-range correlation in the position of the holes yield comparable, or even superior, absorption enhancements than periodic (photonic crystal) patterns. This work provides clear evidence that non-deterministic photonic structures represent a viable alternative strategy for photon management in thin-film solar cells, thereby opening the route towards more efficient and potentially cheaper photovoltaic technologies.

  • 20-02-13;
Our manuscript entitled "Two-dimensional disorder for broadband, omnidirectional and polarization-insensitive absorption" has been published by Optics ExpressAuthors: M. Burresi, F. Pratesi K. Vynck, M. Prasciolu, M. Tormen, and D. S. Wiersma.

The surface of thin-film solar cells can be tailored with photonic nanostructures to allow light trapping in the absorbing medium.This in turn increases the optical thickness of the film and thus enhances their absorption. Such a coherent light trapping is generally accomplished with deterministic photonic architectures. Here, we experimentally explore the use of a different nanostructure, a disordered one, for this purpose. We show that the disorder-induced modes in the film allow improvements in the absorption over a broad range of frequencies and impinging angles.

  • 15-02-13;
Our manuscript entitled "Holey random walks: Optics of heterogeneous turbid composites" has been published by Physical Review EAuthors: T. Svensson, K. Vynck, M. Grisi, R. Savo, M. Burresi, and D. S. Wiersma.

We present a probabilistic theory of random walks in turbid media with nonscattering regions. It is shown that important characteristics such as diffusion constants, average step lengths, crossing statistics, and void spacings can be analytically predicted. The theory is validated using Monte Carlo simulations of light transport in heterogeneous systems in the form of random sphere packings and good agreement is found. The role of step correlations is discussed and differences between unbounded and bounded systems are investigated. Our results are relevant to the optics of heterogeneous systems in general and represent an important step forward in the understanding of media with strong (fractal) heterogeneity in particular.

  • 07-02-13;
Our manuscript entitled "Exploiting breakdown of the similarity relation for diffuse light transport: simultaneous retrieval of scattering anisotropy and diffusion constant" has been published by Optics LettersAuthors: T. Svensson, R. Savo, E. Alerstam, K. Vynck, M. Burresi, and D. S. Wiersma.

As manifested in the similarity relation of diffuse light transport, it is difficult to assess single scattering characteristics from multiply scattered light. We take advantage of the limited validity of the diffusion approximation of light transport and demonstrate, experimentally and numerically, that even deep into the multiple scattering regime, time-resolved detection of transmitted light allows simultaneous assessment of both single scattering anisotropy and scattering mean free path, and therefore also macroscopic parameters like the diffusion constant and the transport mean free path. This is achieved via careful assessment of early light and matching against Monte Carlo simulations of radiative transfer.

  • 09-12-12;
Our recent work published on Nature Materials has been reviewed by a semi-popular online magazine 2Physics.
  • 18-10-12;
Italian press release on the CNR website and the University of Florence web site regarding our manuscript entitled "Photon management in two-dimensional disordered media".

  • 07-10-12;
Our manuscript entitled "Photon management in two-dimensional disordered media" has been accepted by Nature Materials and it has been chosen as an Advance Online Publication.

Elaborating reliable and versatile strategies for efficient light coupling between free
space and thin films is of crucial importance for new technologies in energy efficiency. Nanostructured materials have opened unprecedented opportunities for light management, notably in thin-film solar cells. Efficient coherent light trapping has been accomplished through the careful design of plasmonic nanoparticles and gratings, resonant dielectric particles and photonic crystals. Alternative approaches have used randomly textured surfaces as strong light diffusers to benefit from their broadband and wide-angle properties. Here, we propose a new strategy for photon management in thin films that combines both advantages of an efficient trapping due to coherent optical effects and broadband/wide-angle properties due to disorder. Our approach consists of the excitation of electromagnetic modes formed by multiple light scattering and wave interference in two-dimensional random media. We show, by numerical calculations, that the spectral and angular responses of thin films containing disordered photonic patterns are intimately related to the in-plane light transport process and can be tuned through structural correlations. Our findings, which are applicable to all waves, are particularly suited for improving the absorption efficiency of thin-film solar cells and can provide a new approach for high-extraction-efficiency light-emitting diodes.

  • 04-10-12;
After one year of work in our group Gaurasundar Marc Conley defended his Master Degree Thesis. The topic is transport in correlated disorder and its possible application for photovoltaics (EN) (Thesis).
Another thesis is coming soon.... a busy 2012!
  • 30-07-12;
The first course of the "Joint EPS-SIF International School on Energy 2012" started.

  • 25-07-12;
After one year of work in our group Lorenzo Cortese defended his his Master Thesis. The topic is the fabrication of 3D photonic correlated-disordered structures (Thesis).
  • 21-06-2012;
Diffracition from a woodpile with stopgap at 1.3 m and from a woodpile in which a small amount of disorder has been introduced in a controlled way. Both sample has been realized with a Direct Laser Writing technique.

  • 23-04-2012;
Our manuscript entitled "Pore size assessment based on wall collision broadening of spectral lines of confi.ned gas: experiments on strongly scattering nanoporous ceramics with fine-tuned pore sizes" has been published by Applied Physics BAuthors: T. Svensson, E. Adolfsson, M. Burresi, R. Savo, C. T. Xu, D. S. Wiersma, S. Svanberg.

Wall collision broadening of absorption lines of gases confined in porous media is a recently opened domain of high-resolution
spectroscopy. Here, we present an experimental investigation of its application for pore size assessment. We report on the manufacturing of nanoporous zirconia ceramics with well-defined pore sizes fine-tuned from 50 to 150 nm. The resulting pore structure is characterized using mercury intrusion porosimetry, and the optical properties of these strongly scattering materials are measured using femtosecond photon time-of-flight spectroscopy (transport mean free paths found to be tuned from 2.3 to 1.2 μm as the pore size increase).Wall collision line broadening is studied by performing near-infrared (760 nm) high-resolution diode
laser spectroscopy of confined oxygen molecules. A simple method for quantitative estimation of the pore size is outlined and shown to produce results in agreement with mercury intrusion porosimetry. At the same time, the need for improved understanding of wall collision broadening is emphasized.

  • 26-03-2012;
Our patent on 2D disordered system for photovoltaics application is now published =>;

  • 16-03-12;
I have been appointed as Preposto (loosely, Project Leader) of the research activities of laboratory 9 at Lens.

  • 15-03-12;
Physical Review FOCUS published an article entitled "Light takes a flight backregarding our recent manuscript published by PRL:

"A Lévy flight, like Brownian motion, is a random walk. The difference is that a few very long steps, which are still random and lack a directional preference, dominate the statistics. The walkers in a Lévy flight cover more average distance than those in standard diffusive transport. The resultant “superdiffusive”....." 

The intensity distribution are actual experimental data of the cone profile, whereas the SEM image shows the interior of a Lévy Glass.   

  • 15-03-12;
Our manuscript entitled "Weak localization of light in superdiffusive random systems", has been published by Physical Review  Letters. Authors: M. Burresi, V. Radhalakshmi, R. Savo, J. Bertolotti, K. Vynck, D. S. Wiersma

Lévy flights constitute a broad class of random walks that occur in many fields of research, from biology to economy and geophysics. The recent advent of Le´vy glasses allows us to study Lévy flights— and the resultant superdiffusion—using light waves. This raises several questions about the influence of interference on superdiffusive transport. Superdiffusive structures have the extraordinary property that all points are connected via direct jumps, which is expected to have a strong impact on interference effects such as weak and strong localization. Here we report on the experimental observation of weak localization in Lévy glasses and compare our results with a recently developed theory for multiple scattering in superdiffusive media. Experimental results are in good agreement with theory and allow us to unveil the light propagation inside a finite-size superdiffusive system.

  • 07-03-12;
Our manuscript entitled "Pore size assessment based on wall collision broadening of spectral lines of confi.ned gas: experiments on strongly scattering nanoporous ceramics with fine-tuned pore sizes", by T. Svensson, E. Adolfsson, M. Burresi, R. Savo, C. T. Xu, D. S. Wiersma, S. Svanberg, has been accepted by Applied Physics B.

The longest title ever!

  • 22-02-12;
Our manuscript entitled "Disordered Optical Modes for Photon Management" is ready. Authors: Kevin Vynck, Matteo Burresi, Francesco Riboli, and Diederik S. Wiersma.

  • 21-01-12;
Our manuscript entitled "Enhanced downconversion of UV light by resonant scattering of aluminum nanoparticles" has been published by Optics Letters. Authors: R. Mupparapu, K. Vynck, I. Malfanti, S. Vignolini, M. Burresi, P. Scudo, R. Fusco, D. S. Wiersma

Metallic nanoparticles are known to enhance nonlinear optical processes due to a local enhancement of the optical field. This strategy has been proposed to enhance downconversion in thin film solar cells, but has various disadvantages, among which is the fact that the enhancement occurs only in a tiny volume close to the particles. We report on a very different physical mechanism that can lead to significant downconversion enhancement, namely, that of resonant light scattering, and which is a large volume effect. We show that only a tiny amount of resonantly scattering metallic (aluminum) nanoparticles is enough to create a significant enhancement of the fluorescence of dye molecules in the visible wavelength range. The strategy can be applied in general to increase the emission of UV-absorbing constituents, and is of particular use for solar energy.

  • 18-01-12;
Our manuscript entitled "Weak localization of light in superdiffusive random systems", by M. Burresi, V. Radhalakshmi, R. Savo, J. Bertolotti, K. Vynck, D. S. Wiersma, has been accepted by Physical Review Letters (arXiv);

  • 22-11-11;
Our recent manuscript stemed on plasmonic light concentrators as been accepted by Optics Letters. This work is the result of a collaboration with ENI SpA. Since a patent is pending the title of the manuscript is under embargo.
  • 15-09-11;
After one year of work in our group Filippo Pratesi defended his his Master Thesis. The topic is optical absorption enhancement on 2D mesoscopic systems (Thesis). 

  • 08-05-11;
Our manuscript entitled "Ultra-fast reciprocal-space investigation of cavity-waveguide coupling",
 Authors: M. Burresi, D. van Oosten, B. S. Song, S. Noda, L. Kuipers, has been published by Optics Letters

Local information on the coupling mechanism between the photonic crystal nanocavity and the feeding waveguide is crucial to enable further improvements of the performance of these systems. Although several investigations on such a coupling have already been performed, information on the local dynamic properties remains hidden. In this publication, we present a reciprocal space investigation of the dynamics of light side-coupled to a photonic crystal nanocavity. We find that the coupling is promoted by Bloch harmonics having greater transverse momentum. Furthermore we investigate the degree of interaction of a near-field probe on the dynamics of the photonic crystal nanocavity.

The electric field in the waveguide and cavity pictured in the image (courtesy of D. van Oosten) are actual experimental data. 

  • 17-04-11;
My PhD thesis is not anymore under embargo (FINALLY!!!) and can be downloaded here, on the Amolf website.

  • 11-03-11;
Part of an Italian scientific talk-show celebrating the 150th year of Italian Unification was recorded in the hall of LENS. The topic of the discussion was the Italian excellence in nanotechnology research. The talk-show will be on-line on the 12th of April on RAI STORIA.

  • 01-12-10;
Nature Photonics published an article entitled "Measuring magnetismregarding our recent manuscript published by PRL:

Matteo Burresi and colleagues investigated how the resonance frequency of a nanocavity shifts when a near-field aperture probe is brought close to the cavity surface. They found that when the metallic ring-like aperture of the probe was above an antinode in the magnetic field, the resonance frequency of the cavity blueshifted to shorter wavelengths......" (=>)

  • 04-11-10;
LambdaEnergy partecipated to the Start Cup 2010 CNR-il Sole 24 Ore competition.
Promising industrial contacts have been established.

  • 26-10-2010;
Il Sole 24 Ore published the list of the finalists who can participate to the last part of the challenge.

  • 25-10-2010;
Our  Business Plan (F. Riboli, K. Vynck, M. Burresi and D.S. Wiersma) is one of the finalists in two different competitions which promote new scientific ventures: StartCup 2010 CNR- il Sole 24 Ore and Nanochallenge Intesa San Paolo Start-Up Initiative. The business plane pave the way for future spin-off company which stems from our recent research on nanophotonics for photovoltaics.
  • 24-10-2010;
Our short project  on enhacing the absorption thin-films for photovoltaics has been accepted by Fotonica 2015 for financing. The project is a joint effort of the Complex Systems group (M. Burresi, K. Vynck, F. Riboli and D.S. Wiersma), and LILIT Beam Line group (M. Prasciolu, E. Sovernigo, M. Tormen); 

  • 24-09-2010;
Physical Review FOCUS published an article entitled "Measuring the Magnetism of Lightregarding our 
recent manuscript published by PRL:

"Light is a wave of both electric and magnetic fields, but when these waves strike matter, the weaker effect of the magnetic component has been nearly impossible to detect directly. Now two groups have independently demonstrated that a tiny, metallic probe will interact strongly with the magnetic field of light waves trapped in a sort of semiconductor "box." As....." (=>)

Light-matter interaction has been often used to control cavities. Since the magnetic field of light weakly interact with matter, only the electric component has been used to switch cavities. Several works has been published which shows that the optical properties of nanocavities can be controlled with the use of nano-probes placed in the maximum of the electric field. 
In this work, we show that using a probe with a metal ring-shape apex the optical properties of a nanocavity can be controlled through magnetic interaction. Due to Lenz's law, the vertical component of the magnetic field in the cavity induced a strong magnetic response in the probe, which modifies the magetnic field distribution in the cavity. As a result, we are able to measure the magnetic polarizability of the probe. We anticipate that with high-Q nanocavities would be possible to measure the magnetic polarizability of very small objects, such as molecules, nanotubes, atoms.

  • 02-09-2010;
We applied for an International Patent. Our invention exploits a new disordered-nanophotonics strategies to enhance the light absorpion of thin-films materials.

  • 08-06-2010;
  • Optics Letters published our manuscript entitled "Observation of vortices and field correlations in the near-field speckle of a three dimensional photonic crystal". Authors: S. Vignolini, M. BurresiS. Gottardo, L. Kuipers, D.S. Wiersma.

    Since the advent of photonic crystals, the photonic community struggled to produce photonic crystals with a negligible degree of disorder. So far the disorder present in this materials has been considered as the ‘Devil’ to defeat in order to achieve the full control of light that an ordered photonic crystal promises. Although outstanding results towards this goal have been achieved (in particular for 2D photonic crystals (=>), in some applications (mainly related to ‘slow’ light) even the slightest imperfection of the crystal turns out to drastically reduce the performance of the photonic crystal device. Lately, in order to circumvent this difficulties, a reinvigorated interested towards a controlled disorder in ordered photonic crystal structure is rising (=>). 

    In this work, we investigate the interplay between order and disorder in the near-field of 3D photonic crystal structure. Detecting the near-field speckle pattern generated by the disorder present in the structure with phase sensitivity, we study the field correlations and found that it depends on the impinging polarization. Moreover, we found optical vortices and studied their spatial statistical distribution.

  • 02-06-2010;
Nano Letters published online our manuscript entitled "Negative-index metamaterials: Looking into the unit cell". Authors: M. Burresi, D. Daniela, D. van Oosten, S. Linden; M. Wegener,  L. Kuipers.

Metamaterials are man-made materials engineered at the nanoscale in order to enhance their magnetic response at optical frequencies. As a result this novel media are expected to exhibit fascinating optical properties not present in nature, such as negative index of refraction, invisibility cloaking and superlensing effect. Many of these predicted optical properties have been already experimentally proven by far-field experiments, some of them even in the visible range (=>).

In this Letter, we investigate a state-of-the-art fishnet metamaterial with a phase-sensitive near-field microscope at optical frequencies. We show that the near-field of such a material exhibits a complicated light field pattern within a single unit cell, where the light emerging from the structure experiences phase variation up to π. We experimentally show that new theoretical models beyond the homogeneous media approximation should be developed for describing the near-field response of metamaterials. Our finding is going to be crucial for applications of metamaterial as superlens.

  • 20-05-2010;
Our group succeeded in fabbricating a high quality polymeric (IPL) 3D photonic crystal, a so-called 'woodpile', using Nanoscribe® . Nanoscribe® is a machinery which allows for 3D direct laser writing exploiting two-photon polymerization. With this new equipement we will produce new kind of material to further investigate anomalous light transport.

  • 02-11-2009;
I'm working as postdoc in Diederik Wiersma's group at LENS (Florence, IT);  
  • 22-10-2009;
Science published our manuscript entitled "Probing the magnetic field of light at optical frequencies". Authors: M. Burresi, D. van Oosten, T. Kampfrath, H. Schoenmaker, R. Heideman, A. Leinse,  L. Kuipers.

Since a rapidly varying magnetic field weakly interact with matter, we can probe/detect light only through its electric component: our eyes percieve only the electric field of light. We experimentally prove in this work that with a properly engineered metal-coated near-field probe the magnetic field of light can be directly probed in a photonic structure. We show maps of both magnetic and electric field distribution simultaneously obtained with subwavelength resolution and phase sensitivity. With this technique light can be fully seen in a manner in which not even the human eye can percieve it;
  • 01-09-2009;
My PhD thesis (Nanoscale investigation of light-matter interaction mediated by magnetic and electric coupling) has been printed.  =>