Photonic Provisioning Using a Packaged SOI Hybrid All-Optical Wavelength Converter in a Meshed Optical Network Testbed

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Development of Τb/s photonic routers using integrated circuits on silicon

The thesis focuses on the development of high-speed all-optical systems using silicon photonic integrated components. Four independent processing units have been assembled and evaluated enabling the following routing functionalities. Label detection is performed with high-resolution silicon micro-ring resonators that operate as reconfigurable optical demultiplexers. Control signal generation is performed with hybrid integrated optical flip-flops using Mach-Zehnder interferomteric structures. Wavelength conversion at bit rates up to 160Gb/s is assisted by a compact silicon photonic circuit that incorporates a flip-chip adapted semiconductor optical amplifier (SOA) and two monolithically integrated delay interferometers (DIs). Wavelength routing is performed by arrayed waveguide gratings (AWG) and higher order ring-resonator based cross-connects. Packet contention resolution is implemented by a Mach-Zenhder interferometric structure and two SOA-DI wavelength converters. For the experimental demonstration of the previous photonic circuits, a high-speed system testbed is assembled accommodating data rates up to 160Gb/s.Η παρoύσα διατριβή επικεντρώνεται στην ανάπτυξη οπτικών συστημάτων υπερυψηλής ταχύτητας χρησιμοποιοιώντας μικρο-οπτικά κυκλώματα σε πυρίτιο. Τέσσερα συστήματα οπτικής επεξεργασίας αναπτύσσονται και αξιολογούνται για την εκτέλεση των ακόλουθων λειτουργιών δρομολόγησης. Η ανίχνευση επικεφαλίδας υλοποιείται με μικρο-οπτικούς συντονιστές δακτυλίου (MRRs) οι οποίοι χρησιμοποιούνται ως ρυθμιζόμενα φίλτρα υψηλής ανάλυσης. Η παραγωγή σημάτων ελέγχου επιτυγχάνεται με υβριδικά ολοκληρωμένους οπτικούς μανδαλωτές (Optical Flip-Flops) χρησιμοποιώντας συζευγμένα συμβολόμετρα Μach-Zehnder. Η μετατροπή μήκους κύματος σε ταχύτητες ρυθμοδότησης 160Gb/s υλοποιείται με ένα φωτονικό κύκλωμα σε πυρίτιο ενσωματώνοντας έναν ημιαγώγιμο οπτικό ενισχυτή (SOA) και δύο μονολιθικά ολοκληρωμένα συμβολόμετρα καθυστέρησης (DIs). Η δρομολόγηση των πακέτων πληροφορίας επιτυγχάνεται με συστοιχία φραγμάτων περίθλασης (AWGs) και με δομές συντονιστών δακτυλίου ανώτερης τάξης. Η επίλυση σύγκρουσης πακέτων υλοποιείται με ένα συμβολόμετρο Mach-Zenhder και δύο μετατροπείς μήκους κύματος (SOA-DI). Για την πειραματική επίδειξη των προηγούμενων φωτονικών διατάξεων, αναπτύσσεται ένα σύστημα αξιολόγησης υψίρρυθμων σημάτων εξυπηρετώντας ταχύτητες ρυθμοδότησης έως 160 Gb/s

Development of Tb/s photonic routers using integrated circuits on silicon

185 σ.Η παρoύσα διατριβή επικεντρώνεται στην ανάπτυξη οπτικών συστημάτων υπερυψηλής ταχύτητας χρησιμοποιοιώντας μικρο-οπτικά κυκλώματα σε πυρίτιο. Τέσσερα συστήματα οπτικής επεξεργασίας αναπτύσσονται και αξιολογούνται για την εκτέλεση των ακόλουθων λειτουργιών δρομολόγησης. Η ανίχνευση επικεφαλίδας υλοποιείται με μικρο-οπτικούς συντονιστές δακτυλίου (MRRs) οι οποίοι χρησιμοποιούνται ως ρυθμιζόμενα φίλτρα υψηλής ανάλυσης. Η παραγωγή σημάτων ελέγχου επιτυγχάνεται με υβριδικά ολοκληρωμένους οπτικούς μανδαλωτές (Optical Flip-Flops) χρησιμοποιώντας συζευγμένα συμβολόμετρα Μach-Zehnder. Η μετατροπή μήκους κύματος σε ταχύτητες ρυθμοδότησης 160Gb/s υλοποιείται με ένα φωτονικό κύκλωμα σε πυρίτιο ενσωματώνοντας έναν ημιαγώγιμο οπτικό ενισχυτή (SOA) και δύο μονολιθικά ολοκληρωμένα συμβολόμετρα καθυστέρησης (DIs). Η δρομολόγηση των πακέτων πληροφορίας επιτυγχάνεται με συστοιχία φραγμάτων περίθλασης (AWGs) και με δομές συντονιστών δακτυλίου ανώτερης τάξης. Η επίλυση σύγκρουσης πακέτων υλοποιείται με ένα συμβολόμετρο Mach-Zenhder και δύο μετατροπείς μήκους κύματος (SOA-DI). Για την πειραματική επίδειξη των προηγούμενων φωτονικών διατάξεων, αναπτύσσεται ένα σύστημα αξιολόγησης υψίρρυθμων σημάτων εξυπηρετώντας ταχύτητες ρυθμοδότησης έως 160 Gb/s.The thesis focuses on the development of high-speed all-optical systems using silicon photonic integrated components. Four independent processing units have been assembled and evaluated enabling the following routing functionalities. Label detection is performed with high-resolution silicon micro-ring resonators that operate as reconfigurable optical demultiplexers. Control signal generation is performed with hybrid integrated optical flip-flops using Mach-Zehnder interferomteric structures. Wavelength conversion at bit rates up to 160Gb/s is assisted by a compact silicon photonic circuit that incorporates a flip-chip adapted semiconductor optical amplifier (SOA) and two monolithically integrated delay interferometers (DIs). Wavelength routing is performed by arrayed waveguide gratings (AWG) and higher order ring-resonator based cross-connects. Packet contention resolution is implemented by a Mach-Zenhder interferometric structure and two SOA-DI wavelength converters. For the experimental demonstration of the previous photonic circuits, a high-speed system testbed is assembled accommodating data rates up to 160Gb/s.Χρήστος Ι. Σταματιάδη

Comparison of passive and active canopy sensors for the estimation of vine biomass production

Recent advances in optical designs and electronic circuits have allowed the transition from passive to active proximal sensors. Instead of relying on the reflectance of natural sunlight, the active sensors measure the reflectance of modulated light from the crop and so they can operate under all lighting conditions. This study compared the potential of active and passive canopy sensors for predicting biomass production in 25–32 randomly selected positions of a Merlot vineyard. Both sensors provided estimates of the normalized difference vegetation index (NDVI) from a nadir view of the canopy at veraison that were good predictors of pruning weight. Although the red NDVI of the passive sensors explained more of the variation in biomass (R2 = 0.82), its relationship to pruning weight was nonlinear and was best described by a quadratic regression (NDVI = 0.55 + 0.50 wt-0.21 wt2). The theoretically greater linearity of the amber NDVI-biomass relationship could not be verified under conditions of high biomass. The linear correlation to stable isotope content in leaves (15N) provided evidence that canopy reflectance detected plant stresses as a result of water shortage and limited fertilizer N uptake. Thus, the canopy reflectance data provided by these mobile sensors can be used to improve site-specific management practices of vineyards

Autonomous Home Composting Units for Urban Areas in Greece: The Case Study of the Municipality of Rhodes

A significant issue is reducing the amount of biological waste that is disposed of in landfills, particularly in high-density residential areas. The Wastes Framework Directive (98/2008), in particular, sets forward the legal requirements for source separation in the European Union’s (EU) environmental legislation. The directive sets a target for separate collection of 10% of the organic waste produced in each municipality by 2030, especially with regard to organic waste. The pilot experience of an integrated biowaste management system that supports source separation and urban composting in an Autonomous Composting Unit (ACU) was presented in this study. The Municipality of Rhodes installed five ACUs in various locations. Used food and green waste are the two types of waste that are deposited in the ACUs. The development of a system for the collection of produced biowaste and its treatment at the source, without producing a nuisance, within an urban area, is the goal of this innovation. Since landfilling of mixed municipal solid waste has long been a common practice on the island of Rhodes, as well as in many other locations of insular and mainland Greece, this technique was introduced as a novel implementation and innovation for the region. The results showed that biowaste source separation was successfully carried out by citizens, resulting in high-purity feed. All ACUs produce compost that is of a standard quality. In accordance with the principles of the circular economy, this study showed that ACUs are a sustainable solution for taking a closed unit approach to the biowaste management problem in urban areas

On the Fly All-Optical Packet Switching Using Hybrid WDM/OCDMA Labeling

International audience<p>We introduce a novel design of an all-optical packet routing node that allows for the selection and forwarding of optical packets based on the routing information contained in hybrid wavelength division multiplexing/optical code division multiple access (WDM/OCDMA) labels. A stripping paradigm of optical code-label is adopted. The router is built around an optical-code gate that consists in an optical flip–flop controlled by two fiber Bragg grating correlators and is combined with a Mach–Zehnder interferometer (MZI)-based forwarding gate. We experimentally verify the proof-of-principle operation of the proposed self-routing node under NRZ and OCDMA packet traffic conditions. The successful switching of elastic NRZ payload at 40 Gb/s controlled by DS-OCDMA coded labels and the forwarding operation of encoded data using EQC codes are presented. Proper auto-correlation functions are obtained with higher than 8.1 dB contrast ratio, suitable to efficiently trigger the latching device with a contrast ratio of 11.6 dB and switching times below 3.8 ns. Error-free operation is achieved with 1.5 dB penalty for 40 Gb/s NRZ data and with 2.1 dB penalty for DS-OCDMA packets. The scheme can further be applied to large-scale optical packet switching networks by exploiting efficient optical coders allocated at different WDM channels.</p

A Cybersecurity Culture Survey Targeting Healthcare Critical Infrastructures

Recent studies report that cybersecurity breaches noticed in hospitals are associated with low levels of personnel’s cybersecurity awareness. This work aims to assess the cybersecurity culture in healthcare institutions from middle- to low-income EU countries. The evaluation process was designed and performed via anonymous online surveys targeting individually ICT (internet and communication technology) departments and healthcare professionals. The study was conducted in 2019 for a health region in Greece, with a significant number of hospitals and health centers, a large hospital in Portugal, and a medical clinic in Romania, with 53.6% and 6.71% response rates for the ICT and healthcare professionals, respectively. Its findings indicate the necessity of establishing individual cybersecurity departments to monitor assets and attitudes while underlying the importance of continuous security awareness training programs. The analysis of our results assists in comprehending the countermeasures, which have been implemented in the healthcare institutions, and consequently enhancing cybersecurity defense, while reducing the risk surface

The BOOM project: A new generation of photonic routing subsystems using hybrid integration on silicon-on-insulator waveguide boards

The European BOOM project aims at the realization of high-capacity photonic routers using the silicon material as the base for functional and cost-effective integration. Here we present the design, fabrication and testing of the first BOOMgeneration of hybrid integrated silicon photonic devices that implement key photonic routing functionalities. Ultra-fast all-optical wavelength converters and micro-ring resonator UDWDM label photodetectors are realized using either 4um SOI rib or SOI nanowire boards. For the realization of these devices, flip-chip compatible non-linear SOAs and evanescent PIN detectors have been designed and fabricated. These active components are integrated on the SOI boards using high precision flip-chip mounting and heterogeneous InP-to-silicon integration techniques. This type of scalable and cost-effective silicon-based component fabrication opens up the possibility for the realization of chip-scale, power efficient, Tb/s capacity photonic routers