23 Jan 2018

Michele Scaravilli has successfully defended his Ph.D. thesis in Information Technologies for Engineering entitled “Bloch‐Surface‐Wave Assisted Lab‐on‐Fiber Optrodes”, supervised by Profs. Vincenzo Galdi and Andrea Cusano.

Congratulations Dr. Scaravilli!

1 Dec 2017

Marino Coppolaro has joined the Fields & Waves Lab as a Ph.D. student in Information Technologies for Engineering.

His Ph.D. work will be focused on the study of nonlocal effects in metamaterials.

17 Nov 2017

The call for nominations for the 2018 EurAAP Leopold B. Felsen Award for Excellence in Electrodynamics is open.

The Award was originally established jointly by the University of Siena and the University of Sannio, funded through a donation from Michael and Judy Felsen in fulfillment of the last wishes of their father, Professor Leo Felsen (1924-2005). Since 2015, the Award is established by the European Association on Antennas and Propagation (EurAAP).

The main purpose of the Award is to keep alive Prof. Felsen’s memory and scientific legacy, as well as to foster academic excellence in the electromagnetics community, by giving recognition to outstanding fundamental contributions from early stage researchers in electrodynamics.

The Award, by nomination only, will be presented annually, as a career award, to an early stage researcher. Eligible nominees should be under 40 years of age at the submission deadline. Previous awardees (also from the former Sannio and Siena editions) are not eligible.

The Award consists of a prize of 4,000 euro, which will be funded by the Felsen Family through a donation, and will be officially presented at the banquet of the upcoming 12th European Conference on Antennas and Propagation (EuCAP 2018).

Candidates from all areas of Electromagnetics are eligible to apply. Selection will be based on quality and significance of the candidates’ contributions to the field, and on the recommendation of the referees.

The deadline for submission of the nominations is January 31, 2018.

More details can be found here.

The journal Nanomaterials and Nanotechnology will publish a Special Collection on Recent Advances and Trends in Optical Metamaterials and Metasurfaces, coordinated by the Guest Editors Mirko Barbuto (Niccolò Cusano University), Alessio Monti (Niccolò Cusano University), and Maria Principe (University of Salerno), and Vincenzo Galdi (University of Sannio).

More details and the call for papers can be found here.

The 5th IEEE International Workshop on Metrology for AeroSpace (MetroAeroSpace 2018) will convene in Rome, Italy, from June 20 - 22, 2018.

A special session on Metamaterials for Aerospace is being organized by Vincenzo Galdi (University of Sannio) and Filiberto Bilotti (University of Roma Tre).

More details and the call for papers can be found here.

The XXXV Edition of the EUPROMETA Distributed Doctoral School on Metamaterials will be held in Rome, Italy, from December 18-22, 2017. The school will be focused on Advanced Electromagnetic Materials and Surfaces for Novel Wave Phenomena.

More details can be found here.

14 Sep 2017

We have presented an invited talk [1] at the 19th International Conference on Electromagnetics in Advanced Applications (ICEAA), Verona, Italy, Sep. 11-15, 2017.

1. Moccia, M., Castaldi, G., & Galdi, V. (2017). Some perspectives in aperiodically ordered antenna arrays and metasurfaces. In Proc. 19th International Conference on Electromagnetics in Advanced Applications (ICEAA). Verona, Italy, Sep. 11-15, 2017.
@inproceedings{Moccia_2017-ICEAA,
author = {Moccia, Massimo and Castaldi, Giuseppe and Galdi, Vincenzo},
booktitle = {Proc. 19th International Conference on Electromagnetics in Advanced Applications
(ICEAA)},
title = {Some perspectives in aperiodically ordered antenna arrays and metasurfaces},
year = {2017},
organization = {Verona, Italy, Sep. 11-15, 2017},
month = sep
}

We have presented two talks [1, 2] at the 7th EOS Topical Meeting on Optical Microsystems (OµS) and the 3rd EOS Topical Meeting on Optics at the Nanoscale (ONS), Capri, Italy, Sep. 10-14, 2017.

1. Scaravilli, M., Micco, A., Castaldi, G., Gioffrè, M., Coppola, G., Galdi, V., & Cusano, A. (2017). A study of Bloch-surface-wave sensing platforms for lab-on-fiber technology. In Proc. 7th EOS Topical Meeting on Optical Microsystems (OMS’17). Capri, Italy, Sep. 10-14, 2017.
@inproceedings{Scaravilli_OMS_2017,
author = {Scaravilli, Michele and Micco, Alberto and Castaldi, Giuseppe and Gioffr\e, Mariano and Coppola, Giuseppe and Galdi, Vincenzo and Cusano, Andrea},
title = {A study of Bloch-surface-wave sensing platforms for lab-on-fiber technology},
booktitle = {Proc. 7th EOS Topical Meeting on Optical Microsystems (OMS'17)},
organization = {Capri, Italy, Sep. 10-14, 2017},
year = {2017},
month = sep
}

2. Moccia, M., Castaldi, G., Galdi, V., Liu, S., Wu, R. Y., Cui, T. J., … Andreone, A. (2017). Coding THz metasurfaces with sub-optimal design for diffuse scattering . In Proc. 3rd EOS Topical Meeting on Optics at the Nanoscale (ONS’17). Capri, Italy, Sep. 10-14, 2017.
@inproceedings{Moccia_ONS_2017,
author = {Moccia, M. and Castaldi, G. and Galdi, V. and Liu, S. and Wu, R. Y. and Cui, T. J. and Koral, C. and Papari, G. P. and Andreone, A.},
title = {Coding THz metasurfaces with sub-optimal design for diffuse scattering },
booktitle = {Proc. 3rd EOS Topical Meeting on Optics at the Nanoscale (ONS'17)},
organization = {Capri, Italy, Sep. 10-14, 2017},
year = {2017},
month = sep
}

30 Aug 2017

We have presented an invited talk [1] at the 11th International Congress on Engineered Material Platforms for Novel Wave Phenomena (Metamaterials), Marseille, France, Aug. 28-31, 2017.

1. Galdi, V. (2017). Metasurfaces for field manipulation and sensing. In Proc. International Congress on Engineered Material Platforms for Novel Wave Phenomena (METAMATERIALS). Marseille, France, Aug. 28-31, 2017.
@inproceedings{Galdi_2017-Metamaterials,
author = {Galdi, Vincenzo},
booktitle = {Proc. International Congress on Engineered Material Platforms for Novel Wave Phenomena (METAMATERIALS)},
title = {Metasurfaces for field manipulation and sensing},
year = {2017},
organization = {Marseille, France, Aug. 28-31, 2017},
month = aug
}

Our paper on “Enhancement and interplay of first- and second-order spatial dispersion in metamaterials with moderate-permittivity inclusions” [1] in collaboration with Carlo Rizza (University of l’Aquila) and Alessandro Ciattoni (CNR-SPIN), has been published in Physical Review B as a Rapid Communication.

1. Rizza, C., Galdi, V., & Ciattoni, A. (2017). Enhancement and interplay of first- and second-order spatial dispersion in metamaterials with moderate-permittivity inclusions. Physical Review B 96(8), 081113.

We investigate a class of multilayered metamaterials characterized by moderate-permittivity inclusions and low average permittivity. Via first-principles calculations, we show that in such a scenario, first- and second-order spatial dispersions may exhibit a dramatic and nonresonant enhancement, and may become comparable with the local response. Their interplay gives access to a wealth of dispersion regimes encompassing additional extraordinary waves and topological phase transitions. In particular, we identify a configuration featuring bound and disconnected isofrequency contours. Since they do not rely on high-permittivity inclusions, our proposed metamaterials may constitute an attractive and technologically viable platform for engineering nonlocal effects in the optical range.

@article{IJ128_PRB_96_081113_2017,
title = {Enhancement and interplay of first- and second-order spatial dispersion in metamaterials with moderate-permittivity inclusions},
author = {Rizza, Carlo and Galdi, Vincenzo and Ciattoni, Alessandro},
journal = {Physical Review B},
volume = {96},
issue = {8},
pages = {081113},
numpages = {5},
year = {2017},
month = aug,
publisher = {American Physical Society},
doi = {10.1103/PhysRevB.96.081113},
}

Our paper on “Enhancement and interplay of first- and second-order spatial dispersion in metamaterials with moderate-permittivity inclusions,” in collaboration with Carlo Rizza (University of l’Aquila) and Alessandro Ciattoni (CNR-SPIN), has been accepted for publication as a Rapid Communication in Physical Review B.

An arXiv preprint is available.

Our paper on “Coding metasurfaces for diffuse scattering: Scaling laws, bounds, and sub-optimal design” [1], in collaboration with Tie Jun Cui’s Group (Southeast University), has been published (early view) in Advanced Optical Materials.

1. Moccia, M., Liu, S., Wu, R. Y., Castaldi, G., Andreone, A., Cui, T. J., & Galdi, V. (2017). Coding metasurfaces for diffuse scattering: Scaling laws, bounds, and suboptimal design. Advanced Optical Materials 5(19), 1700455.

Coding metasurfaces, based on the combination of two basic unit cells with out-of-phase responses, have been the subject of many recent studies aimed at achieving diffuse scattering, with potential applications to diverse fields ranging from radar-signature control to computational imaging. Here, via a theoretical study of the relevant scaling-laws, the physical mechanism underlying the scattering-signature reduction is elucidated, and some absolute and realistic bounds are analytically derived. Moreover, a simple, deterministic suboptimal design strategy is introduced that yields results comparable with those typically obtained by approaches based on brute-force numerical optimization, at a negligible fraction of their computational burden, thereby paving the way to the design of structures with arbitrarily large electrical size. Results are corroborated by rigorous full-wave numerical simulations and microwave experiments, and may be of interest in a variety of application fields, such as the design of low-scattering targets and illumination apertures for computational imaging, not necessarily restricted to electromagnetic scenarios.

author = {Moccia, Massimo and Liu, Shuo and Wu, Rui Yuan and Castaldi, Giuseppe and Andreone, Antonello and Cui, Tie Jun and Galdi, Vincenzo},
title = {Coding metasurfaces for diffuse scattering: Scaling laws, bounds, and suboptimal design},
issn = {2195-1071},
year = {2017},
volume = {5},
issue = {19},
month = oct,
pages = {1700455},
}

14 Jul 2017

We have presented two talks [1, 2] at the IEEE AP-S Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting (IEEE-APS/URSI), San Diego, California, USA, July 9-14, 2017.

1. Moccia, M., Liu, S., Wu, R. Y., Castaldi, G., Andreone, A., Cui, T. J., & Galdi, V. (2017). Coding metasurfaces for diffuse scattering: Theoretical bounds and sub-optimal design. In Proc. USNC-URSI Radio Science Meeting. San Diego, CA, USA, July 9-14, 2017.
@inproceedings{Moccia_2017-USNC-URSI,
author = {Moccia, Massimo and Liu, Shuo and Wu, Rui Yuan and Castaldi, Giuseppe and Andreone, Antonello and Cui, Tie Jun and Galdi, Vincenzo},
booktitle = {Proc. USNC-URSI Radio Science Meeting},
title = {Coding metasurfaces for diffuse scattering: Theoretical bounds and sub-optimal design},
year = {2017},
organization = {San Diego, CA, USA, July 9-14, 2017},
month = jul
}

2. Principe, M., Consales, M., Micco, A., Crescitelli, A., Castaldi, G., Esposito, E., … Cusano, A. (2017). Fiber-optics meta-tips for light manipulation and sensing. In Proc. USNC-URSI Radio Science Meeting. San Diego, CA, USA, July 9-14, 2017.
@inproceedings{Principe_2017-USNC-URSI,
author = {Principe, M. and Consales, M. and Micco, A. and Crescitelli, A. and Castaldi, G. and Esposito, E. and La Ferrara, V. and Cutolo, A. and Galdi, V. and Cusano, A.},
booktitle = {Proc. USNC-URSI Radio Science Meeting},
title = {Fiber-optics meta-tips for light manipulation and sensing},
year = {2017},
organization = {San Diego, CA, USA, July 9-14, 2017},
month = jul
}

Our paper on “Coding metasurfaces for diffuse scattering: Scaling laws, bounds, and sub-optimal design,” in collaboration with Tie Jun Cui’s Group (Southeast University), has been accepted for publication in Advanced Optical Materials.

Our paper on “Transformation-optics-based design of a metamaterial radome for extending the scanning angle of a phased array antenna” [1], in collaboration with MBDA, has been published (early view) in the IEEE Journal of Multiscale and Multiphysics Computational Techniques.

1. Moccia, M., Castaldi, G., D’Alterio, G., Feo, M., Vitiello, R., & Galdi, V. (2017). Transformation-optics-based design of a metamaterial radome for extending the scanning angle of a phased array antenna. IEEE Journal on Multiscale and Multiphysics Computational Techniques 2, 159–167.

We apply the transformation-optics approach to the design of a metamaterial radome that can extend the scanning angle of a phased-array antenna. For moderate enhancement of the scanning angle, via suitable parameterization and optimization of the coordinate transformation, we obtain a design that admits a technologically viable, robust and potentially broadband implementation in terms of thin-metallic-plate inclusions. Our results, validated via finite-element-based numerical simulations, indicate an alternative route to the design of metamaterial radomes which does not require negative-valued and/or extreme constitutive parameters.

@article{IJ126_IEEE-JMMCT_2017,
author = {Moccia, M. and Castaldi, G. and D'Alterio, G. and Feo, M. and Vitiello, R. and Galdi, V.},
journal = {IEEE Journal on Multiscale and Multiphysics Computational Techniques},
title = {Transformation-optics-based design of a metamaterial radome for extending the scanning angle of a phased array antenna},
year = {2017},
doi = {10.1109/JMMCT.2017.2713826},
volume = {2},
number = {},
pages = {159--167},
month = {}
}

Our paper on “Transformation-optics-based design of a metamaterial radome for extending the scanning angle of a phased array antenna,” in collaboration with MBDA, has been accepted for publication in the IEEE Journal of Multiscale and Multiphysics Computational Techniques.

An arXiv preprint is available.

28 Apr 2017

We have presented a talk [1] at the 25th Optical Fiber Sensors Conference (OFS), Jeju, Korea, Apr. 24-28, 2017.

1. Principe, M., Consales, M., Micco, A., Crescitelli, A., Castaldi, G., Esposito, E., … Cusano, A. (2017). Optical fiber meta-tips: Perspectives in sensing applications. In Y. Chung, W. Jin, B. Lee, J. Canning, K. Nakamura, & L. Yuan (Eds.), Proceedings of SPIE (Vol. 10323, p. 103233F). 25th Optical Fiber Sensors Conference (OFS), Jeju, Korea, Apr. 24-28, 2017.
@inproceedings{Principe_2017-OFS,
author = {Principe, M. and Consales, M. and Micco, A. and Crescitelli, A. and Castaldi, G. and Esposito, E. and Ferrara, V. L. and Cutolo, A. and Galdi, V. and Cusano, A.},
editor = {Chung, Youngjoo and Jin, Wei and Lee, Byoungho and Canning, John and Nakamura, Kentaro and Yuan, Libo},
booktitle = {Proceedings of SPIE},
title = {Optical fiber meta-tips: Perspectives in sensing applications},
year = {2017},
volume = {10323},
pages = {103233F},
doi = {10.1117/12.2265002},
month = apr,
organization = {25th Optical Fiber Sensors Conference (OFS), Jeju, Korea, Apr. 24-28, 2017}
}

Our paper on “Exceptional points of degeneracy and PT-symmetry in photonic coupled chains of scatterers” [1] in collaboration with Filippo Capolino’s Group (University of California at Irvine), has been accepted for publication in Physical Review B.

1. Othman, M. A. K., Galdi, V., & Capolino, F. (2017). Exceptional points of degeneracy and PT symmetry in photonic coupled chains of scatterers. Physical Review B 95(10), 104305.

We demonstrate the existence of exceptional points of degeneracy (EPDs) of periodic eigenstates in non-Hermitian coupled chains of dipolar scatterers. Guided modes supported by these structures can exhibit an EPD in their dispersion diagram at which two or more Bloch eigenstates coalesce, in both their eigenvectors and eigenvalues. We show the emergence of a second-order modal EPD associated with the parity-time (PT) symmetry condition, at which each particle pair in the double chain exhibits balanced gain and loss. Furthermore, we also demonstrate a fourth-order EPD occurring at the band edge. Such a degeneracy condition was previously referred to as a degenerate band edge in lossless anisotropic photonic crystals. Here, we rigorously show it under the occurrence of gain and loss balance for a discrete guiding system. We identify a more general regime of gain and loss balance showing that PT symmetry is not necessary to attain EPDs. Moreover, we investigate the degree of detuning of the EPD when the geometrical symmetry or balanced condition is broken. Furthermore, we demonstrate a realistic implementation of the EPD in a coupled chain made of pairs of plasmonic nanospheres and active core-shell nanospheres at optical frequencies. These findings open avenues toward superior light localization and transport with application to high-Q resonators utilized in sensors, filters, low-threshold switching and lasing.

@article{IJ125_PRB_95_104305_2017,
title = {Exceptional points of degeneracy and PT symmetry in photonic coupled chains of scatterers},
author = {Othman, Mohamed A. K. and Galdi, Vincenzo and Capolino, Filippo},
journal = {Physical Review B},
volume = {95},
issue = {10},
pages = {104305},
numpages = {12},
year = {2017},
month = mar,
publisher = {American Physical Society},
doi = {10.1103/PhysRevB.95.104305},
}

Our paper on “Optical fiber meta-tips” [1], in collaboration with Andrea Cusano’s Group (University of Sannio), has been published in Light: Science & Applications.

1. Principe, M., Consales, M., Micco, A., Crescitelli, A., Castaldi, G., Esposito, E., … Cusano, A. (2017). Optical fiber meta-tips. Light: Science & Applications 6, e16226.

We report on the first demonstration of a proof-of-principle optical fiber ‘meta-tip’, which integrates a phase-gradient plasmonic metasurface on the fiber tip. For illustration and validation purposes, we present numerical and experimental results pertaining to various prototypes implementing generalized forms of the Snell’s transmission/reflection laws at near-infrared wavelengths. In particular, we demonstrate several examples of beam steering and coupling with surface waves, in fairly good agreement with theory. Our results constitute a first step toward the integration of unprecedented (metasurface-enabled) light-manipulation capabilities in optical-fiber technology. By further enriching the emergent ‘lab-on-fiber’ framework, this may pave the way for the widespread diffusion of optical metasurfaces in real-world applications to communications, signal processing, imaging and sensing.

@article{IJ124_LSA_6_6226a_2017,
author = {Principe, Maria and Consales, Marco and Micco, Alberto and Crescitelli, Alessio and Castaldi, Giuseppe and Esposito, Emanuela and La Ferrara, Vera and Cutolo, Antonello and Galdi, Vincenzo and Cusano, Andrea},
title = {Optical fiber meta-tips},
journal = {Light: Science {\&} Applications},
volume = {6},
pages = {e16226},
year = {2017},
month = mar,
doi = {10.1038/lsa.2016.226},
note = {http://www.nature.com/lsa/journal/v6/n3/suppinfo/lsa2016226s1.html?url=/lsa/journal/v6/n3/full/lsa2016226a.html}
}

Our paper on “Magnified imaging based on non-Hermitian nonlocal cylindrical metasurfaces” [1], in collaboration with Andrea Alù’s Group (University of Texas at Austin), has been published in Physical Review B.

1. Savoia, S., Valagiannopoulos, C. A., Monticone, F., Castaldi, G., Galdi, V., & Alù, A. (2017). Magnified imaging based on non-Hermitian nonlocal cylindrical metasurfaces. Physical Review B 95(11), 115114.

We show that a cylindrical lensing system composed of two metasurfaces with suitably tailored non-Hermitian (i.e., with distributed gain and loss) and nonlocal (i.e., spatially dispersive) properties can perform magnified imaging with reduced aberrations. More specifically, we analytically derive the idealized surface-impedance values that are required for “perfect” magnification and imaging and elucidate the role and implications of non-Hermiticity and nonlocality in terms of spatial resolution and practical implementation. For a basic demonstration, we explore some proof-of-principle quasilocal and multilayered implementations and independently validate the outcomes via full-wave numerical simulations. We also show that the metasurface frequency-dispersion laws can be chosen so as to ensure unconditional stability with respect to arbitrary temporal excitations. These results, which extend previous studies on planar configurations, may open intriguing venues in the design of metastructures for field imaging and processing.

@article{IJ123_PRB_95_115114_2017,
title = {Magnified imaging based on non-Hermitian nonlocal cylindrical metasurfaces},
author = {Savoia, Silvio and Valagiannopoulos, Constantinos A. and Monticone, Francesco and Castaldi, Giuseppe and Galdi, Vincenzo and Al\u, Andrea},
journal = {Physical Review B},
volume = {95},
issue = {11},
pages = {115114},
numpages = {13},
year = {2017},
month = mar,
publisher = {American Physical Society},
doi = {10.1103/PhysRevB.95.115114}
}

Our paper on “Magnified imaging based on non-Hermitian nonlocal cylindrical metasurfaces,” in collaboration with Andrea Alù’s Group (University of Texas at Austin), has been accepted for publication in Physical Review B.

An arXiv preprint is available.

Our paper on “Exceptional points of degeneracy and PT-symmetry in photonic coupled chains of scatterers,” in collaboration with Filippo Capolino’s Group (University of California at Irvine), has been accepted for publication in Physical Review B.

An arXiv preprint is available.

9 Feb 2017

The new website is on!

Details on the design and implementation can be found here.