Papers by Annamaria Gerardino
Spatially Selective Hydrogen Irradiation/Removal of Dilute Nitrides: A Versatile Nanofabrication Tool for Photonic Applications
DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
Tuning and imaging random photonic modes
We demonstrate experimentally the ability to fully control and maps the spectral properties of an... more We demonstrate experimentally the ability to fully control and maps the spectral properties of an individual photonic mode in a two-dimensional disordered photonic GaAs slab with disordered distributions of circular air holes
arXiv (Cornell University), Apr 10, 2015
Arrays of photonic cavities are relevant structures for developing large-scale photonic integrate... more Arrays of photonic cavities are relevant structures for developing large-scale photonic integrated circuits and for investigating basic quantum electrodynamics phenomena, due to the photon hopping between interacting nanoresonators. Here, we investigate, by means of scanning near-field spectroscopy, numerical calculations and an analytical model, the role of different neighboring interactions that give rise to delocalized supermodes in different photonic crystal array configurations. The systems under investigation consist of three nominally identical two-dimensional photonic crystal nanocavities on membrane aligned along the two symmetry axes of the triangular photonic crystal lattice. We find that the nearest and next-nearest-neighbour coupling terms can be of the same relevance. In this case, a non-intuitive picture describes the resonant modes, and the photon hopping between adjacent nanoresonators is strongly affected. Our findings prove that exotic configurations and even post-fabrication engineering of coupled nanoresonators could directly tailor the mode spatial distribution and the group velocity in coupled resonator optical waveguides.
APL photonics, Jul 1, 2016
Omnidirectional excitation of sidewall gap-plasmons in a hybrid gold-nanoparticle/ aluminum-nanop... more Omnidirectional excitation of sidewall gap-plasmons in a hybrid gold-nanoparticle/ aluminum-nanopore structure APL
Applied Physics Letters, Feb 20, 2017
DOI to the publisher's website. • The final author version and the galley proof are versions of t... more DOI to the publisher's website. • The final author version and the galley proof are versions of the publication after peer review. • The final published version features the final layout of the paper including the volume, issue and page numbers. Link to publication General rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights. • Users may download and print one copy of any publication from the public portal for the purpose of private study or research. • You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal. If the publication is distributed under the terms of Article 25fa of the Dutch Copyright Act, indicated by the "Taverne" license above, please follow below link for the End User Agreement:
Merging On-chip and In-silico Modelling for Improved Understanding of Complex Biological Systems
SEMA SIMAI Springer series, 2023
Portable Optical Spectroscopy and Machine Learning Techniques for Quantification of the Biochemical Content of Raw Food Materials
Investigation of Bacterial Interactions Using Lab on Chips
2020 22nd International Conference on Transparent Optical Networks (ICTON), 2020
Many infections, such as pulmonary infections occurring in cystic fibrosis (CF) patients, are pol... more Many infections, such as pulmonary infections occurring in cystic fibrosis (CF) patients, are polymicrobial and caused by a combination of different bacterial species. Sometime, a micro-organism predisposes the host to colonisation by other species, and the microbial cooperation or antagonism govern the infectious sequelae. Staphylococcus aureus is one of the first pathogens infecting CF airways, but during adolescence up to 80% of patients become chronically colonised by Pseudomonas aeruginosa, which causes a progressive pulmonary destruction, although antibiotic therapies can improve life expectancy. To investigate the antagonistic interactions between S. aureus and P. aeruginosa, we have designed and fabricated two different lab-on-chips. The first device consists of three parallel compartments, two are filled with different bacterial species while the central one is an agarose barrier, to avoid direct interaction between bacteria. Also the second microfluidic device is composed of three compartments, but the central one is connected to the other two by 260 microchannels; a cell trap is placed at the center of each microchannel to avoid physical contact between bacterial cells in different compartments. We use fluorescent-tagged bacteria and monitor their growth rate inside the microchannels using confocal microscopy.
The ENEA discharge produced plasma extreme ultraviolet source and its patterning applications
XXII International Symposium on High Power Laser Systems and Applications, 2019
The main characteristics of the ENEA Discharge Produced Plasma (DPP) Extreme Ultraviolet (EUV) so... more The main characteristics of the ENEA Discharge Produced Plasma (DPP) Extreme Ultraviolet (EUV) source are presented together with results of irradiations of various materials. The DPP EUV source, based on a Xe–plasma heated up to a temperature of 30 ÷ 40 eV, emits more than 30 mJ/sr/shot at 10 Hz rep. rate in the 10 ÷ 18 nm wavelength spectral range. The DPP is equipped with a debris mitigation system to protect particularly delicate components needed for patterning applications. The ENEA source has been successfully utilized for sub–micrometer pattern generation on photonic materials and on specifically designed chemically amplified resists. Details down to 100 nm have been replicated on such photoresists by our laboratory–scale apparatus for contact EUV lithography. Preliminary EUV irradiations of graphene films aimed at modifying its properties have been also performed.
The spectral treasure house of miniaturized instruments for food safety, quality and authenticity applications: A perspective
Trends in Food Science & Technology, 2021
Abstract Background Optical technologies, relying on spectral analysis, are more and more impleme... more Abstract Background Optical technologies, relying on spectral analysis, are more and more implemented in portable devices for food analysis. Thereby, each food safety, quality or authenticity provision as well as each technology requires the generation of a dedicated spectral database with reference data. Currently, knowledge on how these databases might be connected or transferred across food commodities, targeted compounds or devices are very limited. Hence, repetitive work is conducted and technologies are not optimally used. Scope and approach This perspective focuses on the currently available technologies and approaches for data handling and database transfer across miniaturized devices and technologies for food safety, quality and authenticity assessments. Key findings and conclusions For almost every food commodity or target compound a miniaturized spectroscopic device can be applied with the respective database to compare findings. Recent developments in optical spectroscopy allow more possibilities for their use as well as facilitate the production of portable devices. A multifunctional device hyphenating several sensors and broadening the application range is still not marketed. Newly developed software architecture accessing and extracting data help to overcome sample heterogenicity or spurious measured data. In addition, several data fusion approaches using machine learning and deep learning strategies are available to fuse spectroscopic data with itself or other non-spectroscopic data. Following the research results presented in this field, spectral data can possibly be re-used and shared across instruments and locations, highly increasing the applicability of data sets. Thereby obstacles such as policy or confidentiality are taken into account.
Advanced Materials, 2018
In article number 1705450, Francesco Biccari and co-workers describe a novel and versatile approa... more In article number 1705450, Francesco Biccari and co-workers describe a novel and versatile approach for the post-growth fabrication of site-controlled, single-photon-emitting quantum dots. This approach, which deploys the hot spot of a near-field microscope to locally remove hydrogen from nanometer-sized regions of a standard GaAs/GaAsN:H/ GaAs quantum well, features state-of-the-art control over both the nanostructure position (<100 nm) and emission energy (≈20 meV).
Physical Review B, 2020
The fabrication of integrated quantum dot (QD)-optical microcavity systems is a requisite step fo... more The fabrication of integrated quantum dot (QD)-optical microcavity systems is a requisite step for the realization of a wide range of nanophotonic experiments (and applications) that exploit the ability of QDs to emit nonclassical light, e.g., single photons. Thanks to their ∼20-nm positioning accuracy and to their proven potential for single-photon operation, the QDs obtained by spatially selective hydrogen irradiation of dilute-nitride semiconductors-such as Ga(AsN) and Ga(PN)-are uniquely suited for integration with photonic nanodevices. In the present work, we demonstrate the ability to deterministically integrate single, site-controlled Ga(AsN)/Ga(AsN):H QDs within a photonic crystal (PhC) cavity. The properties of the fabricated QD-PhC cavity systems are then probed by photon correlation-providing clear evidence of single-photon emission-and time-resolved microphotoluminescence spectroscopy. Detailed information on the dynamics of our integrated nanodevices can be inferred by comparing these experiments to the solutions of a rate-equations system, developed by taking into account all the main processes leading to the capture, relaxation, and recombination of carriers in and out of the QD. This allows us to follow the evolution of the relevant recombination rates in our system for varying energy detuning, E, between the QD and the PhC cavity. When the QD exciton transition is nearly resonant with the cavity mode, a large (>tenfold) enhancement of the spontaneous emission rate is observed, in substantial agreement with Jaynes-Cummings (JC) theory. For intermediate detunings (E ∼ 1.5-3.5 meV), on the other hand, the observed enhancement is significantly larger than that predicted by JC theory, due to the important role played by acoustic phonons in mediating the QD-PhC cavity coupling in a solid-state environment. Apart from its fundamental interest, the observation of such phonon-mediated, broadband enhancement of light-matter interaction significantly relaxes the requirements for the realization of a large variety of cavity QED-based experiments and applications. These include many photonic devices for which the use of site-controlled Ga(AsN)/Ga(AsN):H QDs would be inherently advantageous, such as those based on the coupling between more than one QD and a single cavity mode (e.g., few-QD nanolasers and QD solids).
High circular dichroism and robust performance in planar plasmonic metamaterial made of nano-comma-shaped resonators
Journal of the Optical Society of America B, 2019
Circularly dichroic metasurfaces are highly sought for a plethora of applications; while many alt... more Circularly dichroic metasurfaces are highly sought for a plethora of applications; while many alternative options are present in the literature, it is hard to select an approach that combines high circular dichroism (CD) with stable performances and easy reproducibility. In this work, we have designed and experimentally investigated a planar plasmonic metamaterial based on a comma-shaped geometry, which features such characteristics. We have focused the complexity of realization in the design process, which combines intrinsic chirality and high field localization, while fabrication was executed by using a standard single-step lift-off procedure. We have produced two classes of samples, closely related in shape but differing slightly in designing method and results, both reaching high levels of CD. Experiments on the first reveal the sensibility of the metasurface to geometrical variations due to fabrication non-idealities, as often happens in metamaterials based on surface plasmons and resonances; on the other hand, with the second, we demonstrate that it is possible to guarantee stable peak values on specific wavelength ranges, even when dealing with relevant fabrication tolerances. Moreover, numerical analyses suggest the possibility to reach values converging toward unity. The ease of implementation by using standard fabrication procedures and the robustness of the performance even with fabrication imprecisions make our proposed metamaterial eligible for adoption for further research in high-precision spectroscopy and implementation at industrial scale.
Frontiers in Pharmacology, 2019
The increasing interest for microfluidic devices in medicine and biology has opened the way to ne... more The increasing interest for microfluidic devices in medicine and biology has opened the way to new time-lapse microscopy era where the amount of images and their acquisition time will become crucial. In this optic, new data analysis algorithms have to be developed in order to extract novel features of cell behavior and cell-cell interactions. In this brief article, we emphasize the potential strength of a new paradigm arising in the integration of microfluidic devices (i.e., organ on chip), time-lapse microscopy analysis, and machine learning approaches. Some snapshots of previous case studies in the context of immunotherapy are included as proof of concepts of the proposed strategies while a visionary description concludes the work foreseeing future research and applicative scenarios.
SSRN Electronic Journal, 2018
A major challenge in cancer research is the complexity of the tumor microenvironment, which inclu... more A major challenge in cancer research is the complexity of the tumor microenvironment, which includes the host immunological setting. Inspired by the emerging technology of organ-on-chip, we achieved 3D co-cultures in microfluidic devices (integrating four cell populations: cancer, immune, endothelial, and fibroblasts) to reconstitute ex vivo a human tumor ecosystem (HER2 + breast cancer). We visualized and quantified the complex dynamics of this tumor-onchip, in the absence or in the presence of the drug trastuzumab (Herceptin), a targeted antibody therapy directed against the HER2 receptor. We uncovered the capacity of the drug trastuzumab to specifically promote long cancer-immune interactions (>50 min), recapitulating an anti-tumoral ADCC (antibody-dependent cell-mediated cytotoxicity) immune response. Cancer-associated fibroblasts (CAFs) antagonized the effects of trastuzumab. These observations constitute a proof of concept that tumors-on-chip are powerful platforms to study ex vivo immunocompetent tumor microenvironments, to characterize ecosystem-level drug responses, and to dissect the roles of stromal components.
Abstract A091: IL-33 activates antitumoral toxicity in eosinophils through stimulation of contact-dependent degranulation
Cancer Immunology Research, 2019
The alarmin IL-33 plays pleiotropic roles in allergy, autoimmunity and inflammation through bindi... more The alarmin IL-33 plays pleiotropic roles in allergy, autoimmunity and inflammation through binding to its specific receptor ST2 expressed by most hematopoietic cells. Emerging evidences suggest an involvement of this cytokine also in cancer immunity, although its function remains ill-defined. Eosinophils (EOS) are a rare blood population playing critical roles in allergic inflammation and parasitic responses. We recently showed that EOS play an essential role in anti-tumor responses against melanoma growth and pulmonary metastasis mediated by IL-33 in vivo.In the present study we analyzed the mechanisms by which IL-33 mediates tumor infiltration and antitumoral activities of EOS. We show that IL-33 indirectly stimulates the recruitment of EOS inducing tumor-derived chemokines CCL24 and CCL5. Furthermore, IL-33 directly activates EOS inducing the expression of adhesion molecules, such as the integrin CD11b, resulting in efficient contact-dependent tumor cell killing. In co-culture e...
Ceramics, 2019
In this review, we report on the design, fabrication, and characterization of photonic crystal ar... more In this review, we report on the design, fabrication, and characterization of photonic crystal arrays, made of two and three coupled nanocavities. The properties of the cavity modes depend directly on the shape of the nanocavities and on their geometrical arrangement. A non-negligible role is also played by the possible disorder because of the fabrication processes. The experimental results on the spatial distribution of the cavity modes and their physical characteristics, like polarization and parity, are described and compared with the numerical simulations. Moreover, an innovative approach to deterministically couple the single emitters to the cavity modes is described. The possibility to image the mode spatial distribution, in single and coupled nanocavities, combined with the control of the emitter spatial position allows for a deterministic approach for the study of cavity quantum electrodynamics phenomena and for the development of new photonic-based applications.
Cell Reports, 2018
A major challenge in cancer research is the complexity of the tumor microenvironment, which inclu... more A major challenge in cancer research is the complexity of the tumor microenvironment, which includes the host immunological setting. Inspired by the emerging technology of organ-on-chip, we achieved 3D co-cultures in microfluidic devices (integrating four cell populations: cancer, immune, endothelial, and fibroblasts) to reconstitute ex vivo a human tumor ecosystem (HER2 + breast cancer). We visualized and quantified the complex dynamics of this tumor-onchip, in the absence or in the presence of the drug trastuzumab (Herceptin), a targeted antibody therapy directed against the HER2 receptor. We uncovered the capacity of the drug trastuzumab to specifically promote long cancer-immune interactions (>50 min), recapitulating an anti-tumoral ADCC (antibody-dependent cell-mediated cytotoxicity) immune response. Cancer-associated fibroblasts (CAFs) antagonized the effects of trastuzumab. These observations constitute a proof of concept that tumors-on-chip are powerful platforms to study ex vivo immunocompetent tumor microenvironments, to characterize ecosystem-level drug responses, and to dissect the roles of stromal components.
The Review of scientific instruments, 2018
The knowledge and the manipulation of light polarization state in the vacuum ultraviolet and extr... more The knowledge and the manipulation of light polarization state in the vacuum ultraviolet and extreme ultraviolet (EUV) spectral regions play a crucial role from materials science analysis to optical component improvements. In this paper, we present an EUV spectroscopic ellipsometer facility for polarimetry in the 90-160 nm spectral range. A single layer aluminum mirror to be used as a quarter wave retarder has been fully characterized by deriving the optical and structural properties from the amplitude component and phase difference δ measurements. The system can be suitable to investigate the properties of thin films and optical coatings and optics in the EUV region.
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Papers by Annamaria Gerardino