Marco Meucci

We introduce a time-resolved Monte Carlo simulation framework for designing fluorescent concentrators (FCs) as optical antennas (OAs) in optical wireless communication (OWC). Unlike traditional analytical models, it captures both collection efficiency and temporal response, enabling optimization of dye concentration and geometry. The model is validated against experimental data obtained for two sets of OAs based on Lumogen Red 305 (LR305) and DQ1 dyes over a wide range of fluorophore concentrations, and it consistently reproduces the measured behavior by explicitly accounting for the interplay between key FC parameters, including fluorescence lifetime, quantum yield, absorption and emission spectra, and reabsorption dynamics. This approach not only provides an accurate characterization of FC performance for OWC but also represents a powerful tool for tailoring FCs to specific OWC applications.

We demonstrate the possibility of using 3D‐printed, see‐through planar elements built with commercially available materials as fluorescent Optical Antennas (OAs) for fast Optical Wireless Communication (OWC). OWC represents a key technology in the forthcoming next‐generation communication services (6G), given its intrinsic combination of bandwidth (BW), security, and pervasiveness. In the Visible Light Communication (VLC) approach, ubiquitous white or colored LED sources can also be used as optical transmitters besides providing indoor/outdoor illumination and signaling, strongly fostering the implementation of the Internet of Things (IoT) paradigm. Here, the intrinsic optical properties (such as BW, field of View (FoV), and collection efficiency) of four different fluorescent slabs grown with commercial, non‐optical resins typically employed to realize transparent objects are fully characterized, unveiling for the first time their large potential as receivers in VLC applications. Complete VLC communication tests are reported, demonstrating attainable bit rates larger than 70 Mb s ⁻¹ with On‐Off Keying (OOK) modulation, which could be largely increased toward the Gb s ⁻¹ target exploiting high‐order modulation schemes. This work can have a profound impact toward the full‐fledged implementation of the IoT paradigm, showing that transparent 3D‐printed objects can be exploited as optical front ends in a new class of VLC and OWC receivers.

The development and validation of vehicular applications require extensive testing, often constrained by high costs, logistical challenges, and safety concerns. To address these issues, we introduce Sto-CAV (SimulaTiOn platform for Connected and Automated Vehicles), a novel, flexible, and scalable simulation platform that enables remote access and modular testing for connected and automated vehicle applications. Sto-CAV integrates both virtual and physical components geographically distributed, allowing users to execute simulations without requiring local hardware or software. In addition, Sto-CAV supports heterogeneous vehicle-to-everything (V2X) radio access technologies, including ITS-G5 based on IEEE 802.11p, LTE-V2X and Visible Light Communication (VLC), facilitating the test of beyond 5G vehicular communication scenarios where traditional RF communications meet optical bands. Unlike existing solutions, Sto-CAV emphasizes ease of configuration, remote accessibility, and the integration of heterogeneous communication technologies, thus providing a comprehensive tool for testing vehicular systems, accessible to researchers and developers worldwide. This paper details the design, capabilities, and applications of Sto-CAV, highlighting its potential to advance the testing of innovative vehicle technologies, also when they are geographically distributed, allowing average latencies suitable for quasi-real time applications.

Fluorescent Concentrators (FCs) are set to revolutionize Optical Wireless Communications (OWC), offering significant advantages over traditional receivers, such as large Field of View (FoV) and enhanced optical gain (OG). In this study, three different Optical Antennas are presented and evaluated as OWC receivers, exploiting FCs incorporating different fluorophores. The performances of DQ1 and Lumogen Red 305F (LR305), and a newly synthesized fluorophore (H2) are comparatively tested for solar energy harvesting, never proposed before for OWC. The devices are tested in high bit rate, laser‐based OWC configuration, and for indoor LED‐based Visible Light Communication (VLC) by presenting a realistic indoor VLC transmitter‐receiver (TX‐RX) system embedding high‐power white LEDs as transmitter. The results demonstrate that all the proposed OAs exhibit greater angular stability than traditional detectors, potentially offering greater resilience to misalignment and beam wandering effects, particularly relevant also in Free Space Optical (FSO) configurations. Furthermore, the intrinsic properties of H2 and LR305 make them particularly suited for white‐light VLC applications. Based on a thorough experimental characterization, the work is the first to propose and evaluate in detail the performance of various new OAs, depending on the specific application, highlighting the efficiency of such devices across various OWC fields.

Energy sustainability and interconnectivity are the two main pillars on which cutting‐edge architecture is based and require the realization of energy and intelligent devices that can be fully integrated into buildings, capable of meeting stringent regulatory requirements and operating in real‐world conditions. Luminescent solar concentrators, particularly those based on near‐infrared emitting reabsorption‐free quantum dots, are considered good candidates for the realization of semi‐transparent photovoltaic glazing, but despite important advances in optical property engineering strategies, studies of finished devices suitable for real‐world operation are still lacking. In this paper, the first example of a fully assembled quantum dot luminescent solar concentrator‐based photovoltaic glazing is demonstrated that meets all international standards for photovoltaic and building elements. It is also shown that these devices are capable of functioning as efficient Visible Light Communication (VLC) receivers even under full sunlight, thus combining energy and wireless connectivity functions in a realistic solution for smart, sustainable buildings.

Optical Antennas (OAs) based on Fluorescent Concentrators (FCs) promise a revolution in the deployment of Visible Light Communication (VLC) and Optical Wireless Communication (OWC), due to their inherent advantages over conventional receivers in terms of exceedingly larger field of view (FoV) and optical gain (OG). Whilst FC-based OAs have been demonstrated in VLC applications in a wealth of works embedding monochromatic UV and Blue LED sources, a detailed study demonstrating the performances of OA in white-light VLC (WLC) applications, which is at the basis of the deployment of VLC for Internet of Things (IoT), 6G and pervasive networks, is still lacking. In our work we present and test two 50 mm x 50 mm OAs for WLC, based on two of the most effective fluorophores (Lumogen Red 305 F and DQ1, respectively) used in Luminescent Solar Concentrator (LSC) applications. We perform a detailed characterization of intrinsic and VLC performances, comparing the results with a novel Monte Carlo model accurately describing the photon conversion and propagation processes. Whilst DQ1 represents the most suited solution for high-speed VLC with UV/blue LEDs, our results highlight excellent performances of Lumogen-based OA in white-light settings, outpacing the performances of ordinary photodiode-based receivers. Our results pave the way towards the full-fledged deployment of VLC in IoT applications, where the availability of detectors with large-area, wide FoV and enhanced OG covering the white LEDs emission is a central element.

One of the main challenges in the deployment of visible light communication (VLC) in realistic application fields, such as intelligent transportation systems (ITSs), is represented by the presence of large background noise levels on top of the optical signal carrying the digital information. A versatile and effective digital filtering technique is, hence, crucial to face such an issue in an effective way. In this paper, we present an extensive experimental evaluation of a complete VLC system, embedding a software-defined-radio (SDR)-based digital signal processing (DSP) filter stage, which is tested either indoors, in the presence of strong artificial 100-Hz stray illumination, and outdoors, under direct sunlight. The system employs low-power automotive LED lamps, and it is tested for baud rates up to 1 Mbaud. We experimentally demonstrate that the use of the DSP technique improves 10× the performance of the VLC receiver over the original system without the filtering stage, reporting a very effective rejection of both 100-Hz and solar noise background. Indoors, the noise margin in the presence of strong 100-Hz noise is increased by up to 40 dB, whilst in the outdoor configuration, the system is capable of maintaining error-free communication in direct sunlight conditions, up to 7.5 m, improving the distance by a factor of 1.6 compared to the case without filtering. We believe that the proposed system is a very effective solution for the suppression of various types of noise effects in a large set of VLC applications.

Fluorescent concentrators (FCs) have been recently proposed as optical condensers for visible light communications (VLC) and optical wireless communication (OWC) receivers, with advantages over conventional optical stages in terms of optical gain and field of view (FoV). However, the use of FC‐based receivers in real‐world scenarios is hampered by the need for large resilience of the involved chromophores to sunlight exposure, and availability of large‐area FC substrates with suitable optochemical properties. This paper presents an innovative OWC system, based on a high‐power blue LED and a large‐area FC‐based on CuInS₂quantum dots (Q‐Dots) as receiving optical stage. A thorough characterization of the FC material in terms of conversion efficiency, temporal response, and FoV is provided, along with a full set of outdoor measurements. The combination of the Q‐Dots fluorophores chemico‐physical properties with the strong DC rejection granted by the design receiver stage allows error‐free VLC link distances up to 60 m and baud rates up to 1 Mb/s. This work represents the first demonstration of long‐range VLC links under strong solar irradiance using large‐area FC antennas and paves the way to deployment of long‐range free‐space optical links with minimal susceptibility to misalignments and pointing instabilities between receiver and transmitter.

The recent development of Quantum Cascade Lasers (QCLs) represents one of the biggest opportunities for the deployment of a new class of Free Space Optical (FSO) communication systems working in the mid-infrared (mid-IR) wavelength range. As compared to more common FSO systems exploiting the telecom range, the larger wavelength employed in mid-IR systems delivers exceptional benefits in case of adverse atmospheric conditions, as the reduced scattering rate strongly suppresses detrimental effects on the FSO link length given by the presence of rain, dust, fog, and haze. In this work, we use a novel FSO testbed operating at 4.7 µm, to provide a detailed experimental analysis of noise regimes that could occur in realistic FSO mid-IR systems based on QCLs. Our analysis reveals the existence of two distinct noise regions, corresponding to different realistic channel attenuation conditions, which are precisely controlled in our setup. To relate our results with real outdoor configurations, we combine experimental data with predictions of an atmospheric channel loss model, finding that error-free communication could be attained for effective distances up to 8 km in low visibility conditions of 1 km. Our analysis of noise regimes may have a key relevance for the development of novel, long-range FSO communication systems based on mid-IR QCL sources.