Quantenzentren in Kristallgittern spielen als sogenannte Festkörper-Qubits eine entscheidende Rolle für die Entwicklung der zweiten Quantenrevolution. Das G-Zentrum in Silizium kann hierfür einen wesentlichen Beitrag leisten, da es sich CMOS-kompatibel und damit skalierbar herstellen lässt, es eine scharfe Nullphononenlinie im Bereich der optischen Telekommunikation besitzt und ODMR-aktiv ist. Dies macht es zu einem geeigneten Kandidaten für die Entwicklung photonischer Mikrochips, auf denen Quantentechnologien und Lichtwellenleitung durch eine Spin-Photon-Schnittstelle miteinander verknüpft werden, um somit alle Kriterien zum Aufbau eines Quantennetzwerkes zu erfüllen. In der vorliegenden Arbeit werden G-Zentren durch niederenergetische und räumlich-selektive Ionen-Implantation hergestellt und mittels Photolumineszenz-Spektroskopie und Magnetresonanzmessungen auf ihre optischen und quantenphysikalischen Eigenschaften untersucht. Anhand umfangreicher temperaturabhängiger Ensemble-Messungen in reinem Silizium werden offene Fragen zum Sättigungsverhalten, der Rekombinationsdynamik und der Verschiebung bzw. Verbreiterung der Nullphononenlinie geklärt und die ersten Zerfallszeit-Messungen des angeregten Zustandes des Defektes vorgestellt. Durch die Verwendung von SOI-Proben in Kombination mit niederenergetischer Ionen-Implantation wird weiterhin die erste, jemals in Silizium isolierte Einzelphotonenquelle hergestellt und durch zahlreiche Polarisations- und Korrelationsmessungen als solche identifiziert. Durch die Einzelphotonenmessung erfolgt zusätzlich eine erste Abschätzung der Quanteneffizienz der G-Zentren und die Messung der Lebensdauer des isolierten angeregten Zustandes. Um den Quantenzustand der G-Zentren mittels Mikrowellenfeld manipulieren und sowohl optische als auch elektronisch auslesen zu können, wird ein experimenteller Aufbau beschrieben, mit dem die magnetische Resonanz der G-Zentren in einer SOI-Probe temperaturabhängig bis in den kryogenen Bereich detektiert werden kann. Nach den ersten manuellen Testmessungen wird der Versuchsaufbau durch neue Steuergeräte und eine Automatisierung weiter optimiert, um damit umfangreiche Messungen bei T = 40K und Raumtemperatur durchzuführen. Dabei wird eine mikrowellenabhängige Manipulation der Photolumineszenz der G-Zentren beobachtet, welche mit dem detektierten Photostrom korreliert ist. Die Manipulation der Photolumineszenz wird hauptsächlich auf eine Veränderung der Ladungsträgerdichte aufgrund anderer spinabhängiger Rekombinationszentren zurückgeführt, welche sich an den Grenzflächen des SOI-Schichtstapels bilden. Ideen, um den Einfluss der G-Zentren durch Unterdrückung der anderen Rekombinationszentren zu erhöhen, werden diskutiert.:Bibliografische Beschreibung Referat Abstract Zusammenfassung der Dissertation Contents List of Figures List of Tables Abbreviations 1 Introduction and motivation 1.1 Demand for silicon photonics and quantum technologies 1.2 Description and aim of the project 1.3 Outline 2 Solid-state and optical properties of silicon 2.1 Crystal properties 2.1.1 Structure 2.1.2 Lattice vibrations 2.1.3 Debye-Waller factor 2.1.4 Energy bands 2.2 Defects and doping in silicon 2.2.1 Intrinsic and extrinsic point defects 2.2.2 Line, area and volume defects 2.2.3 Doping 2.3 Luminescence from silicon 2.3.1 Optical properties of bulk silicon 2.3.2 Non-linear effects in silicon 2.3.3 Dislocation loops 2.3.4 Quantum confinement effects 2.3.5 Rare-Earth (Erbium) doping 2.3.6 Light emitting defects in silicon 2.4 G centers in silicon 2.4.1 Structural properties and creation of G centers 2.4.2 Optical properties and applications of G centers 3 Solid-state quantum technologies 3.1 Ion implantation for defect engineering 3.1.1 High-energy accelerator “Lipsion” 3.1.2 100 kV Microbeam 3.2 Quantum optics 3.2.1 Properties of single photons 3.2.2 Photoluminescence and single-photon measurements 3.2.3 Applications of single-photon sources - quantum key distribution 3.3 Quantum computing 3.3.1 Basic principle 3.3.2 Photonic qubits 3.3.3 Solid-state qubits 4 Optical properties of an ensemble of G centers in silicon 4.1 Experiment description and basic properties 4.1.1 Sample fabrication 4.1.2 Optical spectroscopy 4.1.3 PL response of different defect densities 4.1.4 Photoluminescence excitation measurement 4.1.5 Saturation behavior 4.2 Temperature-dependent photoluminescence spectroscopy 4.2.1 Thermal redshift 4.2.2 ZPL broadening 4.2.3 Temperature-dependent PL intensity 4.2.4 Temperature-dependent lifetime and decay rate 4.3 Recombination dynamics 4.3.1 Spectrally selective recombination dynamics 4.3.2 Lifetime and defect density 4.3.3 Phonon-assisted recombination model 5 G centers as single-photon sources in silicon 5.1 Experimental description 5.1.1 Sample fabrication 5.1.2 Optical spectroscopy 5.2 Evidence of a single-photon source 5.2.1 Autocorrelation study 5.2.2 Photodynamics 5.2.3 PL polarization 5.3 Properties of single photons from G centers 5.3.1 ZPL shift 5.3.2 Saturation and stability 5.3.3 Lifetime of an isolated G center 5.3.4 Estimation of the quantum efficiency 6 Optical and photoelectric readout of G centers in silicon 6.1 Setup 6.1.1 Sample preparation 6.1.2 Circuit board and cryostat 6.1.3 Measuring and control devices 6.1.4 PL spectroscopy 6.2 Manual ODMR and PDMR at cryogenic temperature 6.3 Automated PDMR measurements 6.3.1 Spectrum analysis 6.3.2 Etiology 6.3.3 Voltage dependence 6.3.4 Temperature dependence 6.3.5 Laser dependence 6.3.6 Magnetic field dependence 6.4 Automated PDMR and ODMR at cryogenic temperature 6.5 Discussion 6.5.1 Microwave dielectric heating in silicon 6.5.2 Spin-dependent recombination centers in Si and Si/SiO2 interfaces 6.6 Conclusion 7 Summary and outlook Bibliography Danksagung Wissenschaftlicher Werdegang Selbstständigkeitserklärung Erklärung für die Bibliothek / Quantum centers in crystal lattices can form so-called solid-state qubits that play a crucial role for the progress of the second quantum revolution. The G center in silicon can make a significant contribution to this, since it can be fabricated in a CMOS compatible and thus scalable way, it has a sharp zero-phonon line in the optical telecommunication range, and it is ODMR active. This makes it a suitable candidate for the development of photonic microchips, where quantum technologies and optical waveguides are linked by a spin-photon interface, thus fulfilling all the criteria to build a quantum network. In the present work, G centers are fabricated by low-energy and spatially-selective ion implantation and their optical and quantum physical properties are investigated by photoluminescence spectroscopy and magnetic resonance measurements. Using extensive temperature-dependent ensemble measurements in pure silicon, open questions on saturation behavior, recombination dynamics, and zero-phonon line shift as well as broadening are clarified, and the first decay time measurements of the excited state of this defect are presented. By using SOI samples in combination with low-energy ion implantation, the first single-photon source ever isolated in silicon is further fabricated and identified as such by extensive polarization and correlation measurements. The single-photon measurement additionally provides a first estimation of the quantum efficiency of the G centers and the measurement of the lifetime of the isolated excited state. In order to manipulate the quantum state of the G centers by means of a microwave field and to enable an optical as well as an electronical readout, an experimental setup is designed and assembled that allows the temperature-dependent detection of magnetic resonances of G centers in a SOI sample down to the cryogenic range. After the first manual test measurements, the experimental setup is further optimized by new control devices and process automation to allow extensive measurements at T = 40K and room temperature. A microwave-dependent manipulation of the photoluminescence of the G centers is observed, which is correlated with the detected photocurrent. The manipulation of the photoluminescence is mainly attributed to a change in the charge carrier density due to other spin-dependent recombination centers that form at the interfaces of the SOI layer stack. Ideas to increase the influence of the G centers by suppressing the other recombination centers are discussed.:Bibliografische Beschreibung Referat Abstract Zusammenfassung der Dissertation Contents List of Figures List of Tables Abbreviations 1 Introduction and motivation 1.1 Demand for silicon photonics and quantum technologies 1.2 Description and aim of the project 1.3 Outline 2 Solid-state and optical properties of silicon 2.1 Crystal properties 2.1.1 Structure 2.1.2 Lattice vibrations 2.1.3 Debye-Waller factor 2.1.4 Energy bands 2.2 Defects and doping in silicon 2.2.1 Intrinsic and extrinsic point defects 2.2.2 Line, area and volume defects 2.2.3 Doping 2.3 Luminescence from silicon 2.3.1 Optical properties of bulk silicon 2.3.2 Non-linear effects in silicon 2.3.3 Dislocation loops 2.3.4 Quantum confinement effects 2.3.5 Rare-Earth (Erbium) doping 2.3.6 Light emitting defects in silicon 2.4 G centers in silicon 2.4.1 Structural properties and creation of G centers 2.4.2 Optical properties and applications of G centers 3 Solid-state quantum technologies 3.1 Ion implantation for defect engineering 3.1.1 High-energy accelerator “Lipsion” 3.1.2 100 kV Microbeam 3.2 Quantum optics 3.2.1 Properties of single photons 3.2.2 Photoluminescence and single-photon measurements 3.2.3 Applications of single-photon sources - quantum key distribution 3.3 Quantum computing 3.3.1 Basic principle 3.3.2 Photonic qubits 3.3.3 Solid-state qubits 4 Optical properties of an ensemble of G centers in silicon 4.1 Experiment description and basic properties 4.1.1 Sample fabrication 4.1.2 Optical spectroscopy 4.1.3 PL response of different defect densities 4.1.4 Photoluminescence excitation measurement 4.1.5 Saturation behavior 4.2 Temperature-dependent photoluminescence spectroscopy 4.2.1 Thermal redshift 4.2.2 ZPL broadening 4.2.3 Temperature-dependent PL intensity 4.2.4 Temperature-dependent lifetime and decay rate 4.3 Recombination dynamics 4.3.1 Spectrally selective recombination dynamics 4.3.2 Lifetime and defect density 4.3.3 Phonon-assisted recombination model 5 G centers as single-photon sources in silicon 5.1 Experimental description 5.1.1 Sample fabrication 5.1.2 Optical spectroscopy 5.2 Evidence of a single-photon source 5.2.1 Autocorrelation study 5.2.2 Photodynamics 5.2.3 PL polarization 5.3 Properties of single photons from G centers 5.3.1 ZPL shift 5.3.2 Saturation and stability 5.3.3 Lifetime of an isolated G center 5.3.4 Estimation of the quantum efficiency 6 Optical and photoelectric readout of G centers in silicon 6.1 Setup 6.1.1 Sample preparation 6.1.2 Circuit board and cryostat 6.1.3 Measuring and control devices 6.1.4 PL spectroscopy 6.2 Manual ODMR and PDMR at cryogenic temperature 6.3 Automated PDMR measurements 6.3.1 Spectrum analysis 6.3.2 Etiology 6.3.3 Voltage dependence 6.3.4 Temperature dependence 6.3.5 Laser dependence 6.3.6 Magnetic field dependence 6.4 Automated PDMR and ODMR at cryogenic temperature 6.5 Discussion 6.5.1 Microwave dielectric heating in silicon 6.5.2 Spin-dependent recombination centers in Si and Si/SiO2 interfaces 6.6 Conclusion 7 Summary and outlook Bibliography Danksagung Wissenschaftlicher Werdegang Selbstständigkeitserklärung Erklärung für die Bibliothek

京都大学 / 0048 / 新制・論文博士 / 博士(工学) / 乙第13015号 / 論工博第4140号 / 新制||工||1650(附属図書館) / 32943 / (主査)教授 斧 髙一, 教授 木村 健二, 教授 立花 明知 / 学位規則第4条第2項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

There has been a huge surge in data traffic all over the world due to the rise of streamingmedia services and connected devices. The current demand in data traffic has alreadypushed the optical fiber in the internet architecture to the network edges and the trend isto push it as close as possible, to the CPU. Silicon photonics addresses this challenge byenabling miniaturized optical devices that use light to move huge amounts of data at veryhigh speeds with extremely low power. To further improve the data transmission capacity,one can make use of different polarizations of light. However, to take advantage ofdifferent polarizations, devices with on-chip polarization rotation capability are required.This is achieved by a tunable polarization rotator. Moreover, full control of polarizationrotation can also be utilized to realize a new class of components in integrated photonicsincluding polarization mode modulators, multiplexers, filters, as well as switches foradvanced optical signal processing, coherent communications, and sensing.This thesis introduces a novel tunable polarization rotator that uses microelectromechanicalsystems (MEMS) as its actuation principle. When voltage is applied to a MEMStunable silicon cantilever, a mechanical movement occurs, which in turn affects theoptical mode shape travelling through a waveguide, as a result of which the polarizationis rotated. In this work, a MEMS tunable polarization rotator is designed, fabricated,and characterized with a polarization extinction ratio of 10 dB, which works in 1530nm -1570nm wavelength spectrum. In addition to the MEMS tunable polarization rotator,in this thesis, a free standing polarization beam splitter of length 1.4 μm, the shortestreported to-date to our knowledge, was designed, fabricated, and characterized. Thetunable polarization rotator and beam splitter developed in this thesis have the potentialto increase the bandwidth and flexibility of current optical communication networks, andfind further applications in polarization diversity schemes for sensing. / Mängden datatrafik i världen har växt explosionsartat de senaste åren på grund av detökade antalet uppkopplade enheter samt det snabbt växande tjänsterna för strömmad media. Det stora databehovet har redan gjort det nödvändigt att använda högkapacitiva optiska länkar hela vägen till nätverkets kanter och trenden är att optisk dataöverföring används närmare och närmare själva CPU:erna i datorerna som utgör källa och slutpunkt för all data på Internet. Kiselfotonik möter denna utmaning genom att möjliggöra miniatyriserade optiska system som använder ljus för att snabbt överföra stora mängder data med liten effektförbrukning. För att öka kapaciteten ännu mer kan man använda sig av ljusets polarisation. För att göra detta måste man tillhandahålla system för att vrida polarisation på chipp-nivå vilket man kan åstadkomma med en avstämbar polarisationsvridare. Utöver en ökad kapacitet kan den nya kontrollen över polarisation även användas för att skapa nya typer av integrerade optiska komponenter som polarisationsbaserade modulatorer, multiplexers, filter, såväl som switchar för optisk signalbehandling, koherent kommunikation och avkänning.Denna avhandling presenterar en ny avstämbar polarisationsvridare som använder en mikroelektromekanisk (MEMS) aktuator. När en spänning är applicerad på en MEMS balk skapas en mekanisk rörelse som i sin tur påverkar den optiska mod-bilden som propagerar i en integrerad optisk vågledare vilket resulterar i att polarisationen vrids. Denna avhandling innehåller design, tillverkning och karakterisering av en avstämbar polarisationsvridare med en polariseringsgrad på 10 dB i våglängdsområdet 1530-1570 nm. Utöver det presenteras design, tillverkning och karakterisering av frihängande polarisationsfördelare med en längd på endast 1.4 µm, den kortaste hittills rapporterad. Dessa komponenter har potentialen att öka bandbredden och flexibilite befintligaoptiska kommunikationsnät och hitta nya tillämpningar i sensorsystem.

The G-center has recently been identified as the first deterministic single-photon punctual emitter isolated in silicon. This discovery is of great interest for largescale quantum technologies, due to the abilities of silicon in terms of integration and scalability. However, the spontaneous emission rate of the G-center still needs to be controlled in order to engineer a useful Single-Photon Source. This could be achieved by incorporating a single G-center in resonant microcavities to benefit from the Purcell effect. As a first step in this direction, we have studied in this project micro-cavities containing an ensemble of G-centers, more precisely Si micro-disks and micro-rings on oxide, with several objectives: the evaluation of the quality factor of micro-cavities containing G-centers, the demonstration of an optical activity of G-centers after the processing of the silicon micro-structures, and the evaluation of their potential as gain medium for integrated microlasers on SOI. The observation of bright photoluminescence from G-centers and of resonant cavity modes with Q’s in the few thousands range confirms the compatibility of G-centers with standard silicon processing steps, and is encouraging for future quantum optics experiments on isolated G centers in micro-cavities. Our results also tend to show that gain may be available in the material, but residual absorption still needs to be decreased to achieve lasing. / G-center har nyligen identifierats som den första determinitiska ponctual enfoton källen isolerad i kisel. Denna upptäckt är av stort intresse för kvantteknologier p.g.a. kisels förmåga gällande integration och skalbarhet. G-centers spontana rekombinationshastighet behöver dock kontrolleras för att skapa en användbar enfoton källa. Det kan göras genom Purcell-effekten i en optisk resonator. Som ett första steg har vi studerat mikroresonatorer som innehåller G-center i det presenterade projektet, med flera mål: utvärdering av kvalitetsfaktor för mikroresonatorer som innehåller G-center, demonstration av optisk aktivitet av G-center efter tillverkning av kiselmikrostrukturer, och utvärdering av deras potential för integrerade mikrolaser på SOI. Observation av stark fotoluminescens av G-center och resonatormoder med stor-Q bekräftar kompatibilitet mellan G-center och vanliga steg för bearbetning av kisel, och är uppmuntrande för framtida Kvantum Optik experimenter med isolerade G-center i mikroresonatorer. Resultaten visar att ljusförstärkning troligtvis börjar, men absorption av andra defekter måste minskas för att uppnå laserregim.

Silicon photonics has been a rapidly growing subfield of integrated optics and optoelectronic in the last decade and is currently considered a mature technology. The main thrust behind the growth is its compatibility with the mature and low-cost microelectronic integrated circuits fabrication process. In recent years, several active and passive photonic devices and circuits have been demonstrated on silicon. Optical delay lines are among important silicon photonic devices, which are essential for a variety of photonic system applications including optical beam-forming for controlling phased-array antennas, optical communication and networking systems and optical coherence tomography. In this thesis, several types of delay lines based on apodized grating waveguides are proposed and demonstrated. Simulation and experimental results suggest that these novel devices can provide high optical delay and tunability at very high bit rate. While most of silicon photonics research has focused in the near-infrared wavelengths, extending the operating wavelength range of the technology into in the 3–5 µm, or the mid-wave infrared regime, is a more recent field of research. A key challenge has been that the standard silicon-on-insulator waveguides are not suitable for the midinfrared, since the material loss of the buried oxide layer becomes substantially high. Here, the silicon-on-sapphire waveguide technology, which can extend silicon’s operating wavelength range up to 4.4 µm, is investigated. Furthermore, silicon-on-nitride waveguides, boasting a wide transparent range of 1.2–6.7 μm, are demonstrated and iv characterized for the first time at both mid-infrared (3.39 μm) and near-infrared (1.55 μm) wavelengths.

Silicon photonics (SiP) has evolved into a mature platform for cost-effective low power compact integrated photonic microsystems for many applications. There is a looming capacity crunch for telecommunications infrastructure to overcome the data-hungry future, driven by streaming and the exponential increase in data traffic from consumer-driven products. To increase data capacity, researchers are now looking at the wavelength window of the thulium-doped fiber amplifier (TDFA), centered near 2 µm as an attractive new transmission window for optical communications, motivated by the demonstrations of low loss, low nonlinearity, and high bandwidth transmission. Large-scale implementation of SiP telecommunication infrastructure will require light sources (lasers) and amplifiers to generate signals and boost transmitted and/or received signals, respectively. Silicon (Si) and silicon nitride (Si3N4) have become the leading photonic integrated circuit (PIC) material platforms, due to their low-cost and wafer-scale production of high-performance circuits. Silicon does however have a number of limitations as a photonic material, including that it is not an ideal light-emitting/amplifying material. This proposed research pertains to the fabrication of on-chip silicon and silicon nitride lasers and amplifiers to be used in a newly accessible optical communications window of the TDFA band, which is a significant step towards compact PICs for the telecommunication networks. Tellurium oxide (TeO2) is an interesting host material due to its large linear and non-linear refractive indices, low material losses and large rare-earth dopant solubility showing good performance for compact low-loss waveguides and on-chip light sources and amplifiers. Chapter 1 provides an overview of silicon photonics in the context of particularly rare earth lasers and amplifiers, operating at extended wavelengths enabled by the Thulium doped fiber amplifier. Chapter 2 presents a theoretical performance of waveguides and microresonators as the efficient structure for laser and amplifiers applications designed for optimized use in Erbium and Thulium doped fiber amplifier wavelength bands. Then spectroscopic study thulium (Tm3+) has been studied as the rare earth element for Thulium doped fiber amplifier wavelength bands. Chapter 3 presents an experimental study of TeO2:Tm3+ coated Si3N4 waveguide amplifiers with internal net gains of up to 15 dB total in a 5-cm long spiral waveguide. Chapter 4 provides a study of TeO2:Tm3+ -coated Si3N4 waveguide lasers with up to 16 mW double-sided on-chip output power. Chapter 5 presents an experimental study of low loss and high-quality factor silicon microring resonators coated with TeO2 for active, passive, and nonlinear applications. Chapter 6 represents the first demonstration of an integrated rare-earth silicon laser, with high performance, including single-mode emission, a lasing threshold of 4 mW, and bidirectional on-chip output powers of around 1 mW. Further results with a different design are presented showing lasers with more than 2 mW of double-sided on-chip output power, threshold pump powers of < 1 mW and lasing at wavelengths over a range of > 100 nm. Importantly, a simple, low-cost design was used which is compatible with silicon photonics foundry processes and enables wafer scale integration of such lasers in SiP PICs using robust materials. Chapter 7 summarizes the thesis and provides paths for future work. / Dissertation / Doctor of Engineering (DEng)

No description available.

<p>A glass-clad, slow-light photonic-crystal waveguide is proposed as a solution to sub-bandgap light detection in silicon photonic circuits. Such detection in silicon is perceived as a challenge owing to silicon's indirect band gap and transparency to 1550nm wavelengths, yet is essential for achieving low-cost, high-yield integration with today's microelectronics industry. Photonic crystals can be engineered in such a way as to enhance light-matter interaction over a specific bandwidth via the reduction of the group velocity of the propagating wave (i.e. the slowing of light). The interaction enhanced for light detection in the present work is electron-hole pair generation at defect sites. The intrinsic electric field of a p-i-n junction enables light detection by separating the electron-hole pairs as a form of measurable current. The photonic-crystal waveguides are designed to have bandwidths in the proximity of a wavelength of 1550nm. Refractive indices of over 80 near the photonic-crystal waveguide's Brillouin zone boundary are measured using Fourier transform spectral interferometry and are found to correspond to numerical simulations. Defect-induced propagation loss was seen to scale with group index, from 400dB/cm at a group index of 8 to 1200dB/cm at a group index of 88. Scaling was sublinear, which is believed to be due to the spreading of modal volume at large group index values. Photodetectors were measured to have responsivities as high as 34mA/W near the photonic-crystal waveguide's Brillouin zone boundary for a reverse bias of 20V and a remarkably short detector length of 80um. The fabrication of each device is fully CMOS-compatible for the sake of cost-effective integration with silicon microelectronics.</p> / Master of Applied Science (MASc)

[EN] Optical technologies are the backbone of modern communication systems providing high-speed access to the Internet, efficient inter and intra-data center interconnects and are expending towards growing research fields and new markets such as satel- lite communications, LIDARs (Laser Imaging Detection and Ranging) applications, Neuromorphic computing, and programable photonic circuits, to name a few. Be- cause of its maturity and low-cost, silicon photonics is being leveraged to allow these new technologies to reach their full potential.As a result, there is a strong need for innovative, high-speed and energy-efficient photonic integrated building blocks on the silicon platform to increase the readiness of silicon photonic integrated circuits. The work developed and presented in this thesis is focused on the design and char- acterization of advanced passive and active devices, for photonic integrated circuits. The thesis consists of three main chapters as well as a motivation and concluding sections exposing the rationale and the accomplishments of this work. Chapter one describes the design and characterization of an electro-optical Mach-Zehnder mod- ulator embedded in highly efficient vertical pn junction exploiting the free-carrier dispersion effect in the O-band.. Chapter two is devoted to the design and charac- terization of a novel geometry of asymmetrical multimode interference device and its implementation in a Mach-Zehnder modulator. Chapter three is dedicated to the design and characterization of innovative 1-dimensional photonic crystal designs for slow- lightmodulation applications. An extensive analysis of the main trade-off arising from the use of slow light is presented. / [ES] Las tecnologías ópticas son el eje vertebrador de los sistemas de comunicación mod- ernos que proporcionan acceso de alta velocidad a la Internet, interconexiones efi- cientes entre centros de datos y dentro de ellos. Además, se están expandiendo hacia campos de investigación crecientes y nuevos mercados como son las aplicaciones de comunicaciones por satélite, los LIDAR (Laser Imaging Detection and Ranging), la computación neuromórfica y los circuitos fotónicos programables, por nombrar algunos. La fotónica de silicio está considerada y aceptada ampliamente como una de las tecnologías clave para que dichas aplicaciones puedan desarrollarse. Como resultado, hay una fuerte necesidad de estructuras fotónicas básicas integradas que sean innovadoras, que soporten altas velocidades de transmisión y que sean más eficientes en términos de consumo de potencia, a fin de aumentar la capacidad de los circuitos integrados fotónicos de silicio. El trabajo desarrollado y presentado en esta tesis se centra en el diseño y la car- acterización de dispositivos avanzados pasivos y activos, para circuitos fotónicos integrados. La tesis consta de tres capítulos principales, así como de sendas sec- ciones de motivación y conclusiones que exponen los fundamentos y los logros de este trabajo. El capítulo uno describe el diseño y la caracterización de un modulador electro-óptico Mach-Zehnder incorporado en una unión pn vertical altamente eficien- ciente que explota el efecto de dispersión de plasma en banda O. El capítulo dos está dedicado al diseño y caracterización de una nueva geometría de dispositivo de interferencia multimodo asimétrico y su aplicación en un modulador Mach-Zehnder. El capítulo tres está dedicado al diseño y caracterización de innovadores cristales fotónicos unidimensionales para aplicaciones de modulación con luz lenta. Se pre- senta un amplio análisis de los principales retos derivados del uso de la misma. / [CA] Les tecnologies òptiques són l'eix vertebrador d'aquells sistemes de comunicació moderns que proporcionen accés d'alta velocitat a la Internet, així com intercon- nexions eficients inter i entre centres de dades. A més a més, s'estan expandint cap a camps d'investigació creixents i nous mercats com són les aplicacions de co- municacions per satèl·lit, els LIDAR (Laser Imaging Detection and Ranging), la computació neuromòrfica i els circuits fotònics programables, entre d'altres. La fotònica de silici és considerada i acceptada àmpliament com una de les tecnologies clau i necessàries perquè aquestes aplicacions puguen desenvolupar-se. Per aquest motiu, es fa necessària l'existència d'estructures fotòniques bàsiques integrades que siguen innovadores, que suporten altes velocitats de transmissió i que siguen més eficients en termes de consum de potència, a fi d'augmentar la capacitat dels cir- cuits integrats fotònics de silici. El treball desenvolupat i presentat en aquesta tesi se centra en el disseny i la caracterització de dispositius avançats passius i actius, per a circuits fotònics integrats. La tesi consta de tres capítols principals, així com d'una secció de motivació i una altra de conclusions que exposen els fonaments i els assoliments d'aquest treball. El capítol u descriu el disseny i la caracterització d'un modulador electro-òptic Mach-Zehnder incorporat en una unió pn vertical d'alta efi- ciència que explota l'efecte de dispersió de plasma en la banda O. El capítol dos està dedicat al disseny i caracterització d'una nova geometria de dispositiu d'interferència multimode asimètric així com a la seua aplicació en un modulador Mach-Zehnder. El capítol tres està dedicat al disseny i caracterització d'innovadors cristalls fotònics unidimensionals per a aplicacions de modulació amb llum lenta. S'inclou també una anàlisi detallada dels principals reptes derivats de l'ús d'aquest tipus de llum. / I want to thank you the Generelitat Valenciana and the European Project L3MATRIX for the funding, without them my doctorate would not taken place. / Zanzi, A. (2020). Passive and active silicon photonics devices at TLC telecommunication wavelengths for on-chip optical interconnects [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/149377

Optical interconnects based on CMOS compatible photonic integrated circuits are regarded as a promising technique to tackle the issues traditional electronics faces, such as limited bandwidth, latency, vast energy consumption and so on. In recent years, plasmonic integrated components have gained great attentions due to the properties of nano-scale confinement, which may potentially bridge the size mismatch between photonic and electronic circuits. Based on silicon nanowire platform, this thesis work studies the design, fabrication and characterization of several integrated plasmonic components, aiming to combine the benefits of Si and plasmonics. The basic theories of surface plasmon polaritons are introduced in the beginning, where we explain the physics behind the diffraction-free confinement. Numerical methods frequently used in the thesis including finite-difference time-domain method and finite-element method are then reviewed. We summarize the device fabrication techniques such as film depositions, e-beam lithography and inductively coupled plasma etching as well as characterization methods, such as direct measurement method, butt coupling, grating coupling etc. Fabrication results of an optically tunable silicon-on-insulator microdisk and III-V cavities in applications as light sources for future nanophotonics interconnects are briefly discussed. Afterwards we present in details the experimental demonstrations and novel design of plasmonic components. Hybrid plasmonic waveguides and directional couplers with various splitting ratios are firstly experimentally demonstrated. The coupling length of two 170 nm wide waveguides with a separation of 140 nm is only 1.55 µm. Secondly, an ultracompact polarization beam splitter with a footprint of 2×5.1 μm2 is proposed. The device features an extinction ratio of 12 dB and an insertion loss below 1.5 dB in the entire C-band. Thirdly, we show that plasmonics offer decreased bending losses and enhanced Purcell factor for submicron bends. Novel hybrid plasmonic disk, ring and donut resonators with radii of ~ 0.5 μm and 1 μm are experimentally demonstrated for the first time. The Q-factor of disks with 0.5 μm radii are                         , corresponding to Purcell factors of . Thermal tuning is also presented. Fourthly, we propose a design of electro-optic polymer modulator based on plasmonic microring. The figure of merit characterizing modulation efficiency is 6 times better comparing with corresponding silicon slot polymer modulator. The device exhibits an insertion loss below 1 dB and a power consumption of 5 fJ/bit at 100 GHz. At last, we propose a tightly-confined waveguide and show that the radius of disk resonators based on the proposed waveguide can be shrunk below 60 nm, which may be used to pursue a strong light-matter interaction. The presented here novel components confirm that hybrid plasmonic structures can play an important role in future inter- and intra-core computer communication systems. / <p>QC 20140404</p>