Birefringence effects in multi-core fiber: coupled local-mode theory

© 2016 Optical Society of America. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modifications of the content of this paper are prohibitedIn this paper, we evaluate experimentally and model theoretically the intra- and inter-core crosstalk between the polarized core modes in single-mode multi-core fiber media including temporal and longitudinal birefringent effects. Specifically, extensive experimental results on a four-core fiber indicate that the temporal fluctuation of fiber birefringence modifies the intra- and inter-core crosstalk behavior in both linear and nonlinear optical power regimes. To gain theoretical insight into the experimental results, we introduce an accurate multi-core fiber model based on local modes and perturbation theory, which is derived from the Maxwell equations including both longitudinal and temporal birefringent effects. Numerical calculations based on the developed theory are found to be in good agreement with the experimental data.This work has been partly funded by Spain National Plan project MINECO/FEDER UE XCORE TEC2015-70858-C2-1-R; HIDRASENSE RTC-2014-2232-3; European Regional Development Fund (ERDF) and the Galician Regional Government under project GRC2015/018. A. Macho and M. Morant work was supported by BES-2013-062952 F.P.I. Grant and postdoc UPV PAID-10-14 program, respectively.Macho-Ortiz, A.; García Meca, C.; Fraile-Peláez, FJ.; Morant Pérez, M.; Llorente Sáez, R. (2016). Birefringence effects in multi-core fiber: coupled local-mode theory. 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Particle Detectors R&D: Dual-Readout Calorimetry for Future Colliders and MicroMegas Chambers for the ATLAS New Small Wheel Upgrade

The thesis presents selected topics on the development of particle detectors for present and future experiments in high energy physics. It is crafted on the work carried out in the three-years period, from October 2017 to October 2020, spent as a student of the XXXIII PhD Cycle in Physics of the University of Pavia and associate member of the National Institute of Nuclear Physics (INFN). The first part concerns my activity as a member of the INFN RD_FCC Collaboration for the study of physics at future circular colliders. It is dedicated to calorimeter design, both software and hardware oriented, for applications at future electron-positron circular colliders. The substantial contribution that the dual-readout calorimetry method would bring to the precision physics program envisaged has been demonstrated. Through a detailed and original work of full-simulation of the IDEA Detector calorimeter, it was shown that a dual-readout fiber calorimeter can satisfy the most stringent requirements on hadronic calorimetry, by exploiting calibration and reconstruction approaches that are unique among future detectors. Several results, such as the discrimination of the W/Z bosons by reconstructing the invariant masses of two-jet final states, were reported for the first time. It is also worth noting the development of a simulation software, based on the Geant4 toolkit, capable of reproducing the expected detector features. This software underlies future studies on the subject. A dual-readout fiber calorimeter operating at future multi-purpose experiments would require a scalable Cherenkov and scintillation light readout system and this set the recent hardware oriented research program. In particular, the use of Silicon PhotoMultipliers for the purpose was pioneered, demonstrating a substantial improvement in the collection of Cherenkov light with respect to previous prototypes, and opening up the possibility of sampling particle showers with an unprecedented granularity. Also in this case, the results obtained are original and chart the activities for next years whose path is drawn in the document. Given their importance and being ahead of the times, these activities contributed to the dawn of the IDEA Experiment. Exploiting the studies performed, the sensitivity of the IDEA Detector, coupled to the CERN future circular electron-positron collider, for Beyond-Standard-Model Axion-Like-Particles (ALPs) search was investigated. ALPs have been considered as produced in the decays of heavy Standard Model resonances and decaying into two photons. The possibility of distinguishing the weak signal with respect to the expected background has been analyzed and the result demonstrated the uniqueness of the experiment compared to the current and future probes. The second part focuses on my work as a member of the ATLAS Experiment at CERN. Together with the ATLAS-Pavia Group, I worked on the construction of MicroMegas chambers for the New Small Wheel (NSW) upgrade, a new detector to be installed in the ATLAS forward muon spectrometer. From 2017 to 2020 all the needed SM1-type MicroMegas chambers have been built in a huge collaboration among Italian Universities and INFN. The readout panels construction and testing at the University of Pavia and INFN Sezione di Pavia was described and the results found to fulfill the ATLAS requirements. In 2019, thanks to the award of an INFN Simil-Fellowship position, I joined the CERN NSW Integration Group and participated to the detector testing phase. Particular attention was given to the detector high-voltage instability problems that severely affected the first phase of the project. The origin of the high-voltage instabilities was understood thanks to a long detector characterization through irradiation at the CERN Gamma Irradiation Facility. Once an ad hoc solution was found, the monitored detector quality, as reported in the document, substantially improved

Novel Specialty Optical Fibers and Applications

Novel Specialty Optical Fibers and Applications focuses on the latest developments in specialty fiber technology and its applications. The aim of this reprint is to provide an overview of specialty optical fibers in terms of their technological developments and applications. Contributions include:1. Specialty fibers composed of special materials for new functionalities and applications in new spectral windows.2. Hollow-core fiber-based applications.3. Functionalized fibers.4. Structurally engineered fibers.5. Specialty fibers for distributed fiber sensors.6. Specialty fibers for communications

Next Generation Silicon Photonic Transceiver: From Device Innovation to System Analysis

Silicon photonics is recognized as a disruptive technology that has the potential to reshape many application areas, for example, data center communication, telecommunications, high-performance computing, and sensing. The key capability that silicon photonics offers is to leverage CMOS-style design, fabrication, and test infrastructure to build compact, energy-efficient, and high-performance integrated photonic systems-on- chip at low cost. As the need to squeeze more data into a given bandwidth and a given footprint increases, silicon photonics becomes more and more promising. This work develops and demonstrates novel devices, methodologies, and architectures to resolve the challenges facing the next-generation silicon photonic transceivers. The first part of this thesis focuses on the topology optimization of passive silicon photonic devices. Specifically, a novel device optimization methodology - particle swarm optimization in conjunction with 3D finite-difference time-domain (FDTD), has been proposed and proven to be an effective way to design a wide range of passive silicon photonic devices. We demonstrate a polarization rotator and a 90◦ optical hybrid for polarization-diversity and phase-diversity communications - two important schemes to increase the communication capacity by increasing the spectral efficiency. The second part of this thesis focuses on the design and characterization of the next- generation silicon photonic transceivers. We demonstrate a polarization-insensitive WDM receiver with an aggregate data rate of 160 Gb/s. This receiver adopts a novel architecture which effectively reduces the polarization-dependent loss. In addition, we demonstrate a III-V/silicon hybrid external cavity laser with a tuning range larger than 60 nm in the C-band on a silicon-on-insulator platform. A III-V semiconductor gain chip is hybridized into the silicon chip by edge-coupling to the silicon chip. The demonstrated packaging method requires only passive alignment and is thus suitable for high-volume production. We also demonstrate all silicon-photonics-based transmission of 34 Gbaud (272 Gb/s) dual-polarization 16-QAM using our integrated laser and silicon photonic coherent transceiver. The results show no additional penalty compared to commercially available narrow linewidth tunable lasers. The last part of this thesis focuses on the chip-scale optical interconnect and presents two different types of reconfigurable memory interconnects for multi-core many-memory computing systems. These reconfigurable interconnects can effectively alleviate the memory access issues, such as non-uniform memory access, and Network-on-Chip (NoC) hot-spots that plague the many-memory computing systems by dynamically directing the available memory bandwidth to the required memory interface