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In der vorliegenden Dissertationsschrift wird die Realisierbarkeit einer polymeroptischen Auswerteeinheit mittels Laserdirektlithographie gezeigt. Die Arbeit adressiert neben der Simulation auch die Herstellung, Charakterisierung und Evaluieren von ausschlie��lich aus Polymermaterialien hergestellten Arrayed Waveguide Gratings (AWG). AWG sind integrierte optische Wellenl��ngendemultiplexer und werden in dieser Arbeit zur Detektion von optischen Wellenl��ngenverschiebungen verwendet. Im Besonderen wird dabei der Fokus auf die Herstellung der AWG mittels Laserdirektlithographie gelegt. Die zurzeit am Markt erh��ltlichen AWGs werden zum gr����ten Teil aus Silizium oder anderen Halbleitermaterialen gefertigt. Die Herstellung solcher anorganischen Bauteile ist aufwendig, erfordern viele Prozessschritte unter Reinraumbedingungen und sind damit sehr kostenintensiv. Polymere bieten unter diesen Gesichtspunkten eine kosteng��nstige Alternative zu den anorganischen Materialien, da sie wesentlich preiswerter zu erwerben, einfacher zu verarbeiten und entsprechend auch kosteng��nstiger in der Produktion sind. In dieser Arbeit wird erstmals ein Polymer-AWG pr��sentiert, welches ausschlie��lich mittels Laserdirektlithographie hergestellt wurde. Diese maskenlose Lithographiemethode zeichnet sich vor allem durch ihre Flexibilit��t aus, was dieses Verfahren besonders f��r Anwendungen im Bereich der Entwicklung und Forschung oder f��r die Produktion von Kleinstserien pr��destiniert. Neuerungen im AWG-Design k��nnen durch einfache und effizient implementierbare ��nderungen der Grafikstrukturdatei vorgenommen werden. Wegen der inh��renten ��hnlichkeit mit maskenbasierten Lithographiemethoden kann der Prozess problemlos in eine andere Methode mit h��herem Durchsatz ��berf��hrt werden, sobald das optimale Design mit der gew��nschten Funktionalit��t identifiziert wurde. Neben ausf��hrlichen Simulationen, um die idealen Abmessungen der AWG unter Ber��cksichtigung der M��glichkeiten der verwendeten Herstellungsmethode und den Parametern der verarbeiteten Materialien zu finden, wurden umfangreiche Studien zur Optimierung der Parameter f��r das verwendete Lithographiesystem angestellt. Aufbauend auf diesen Erkenntnissen wurden AWG mit 3 und 16 Ausgangskan��len auf einer Cycloolefin-Copolymer- beziehungsweise Polyimid-Substratfolie mit dem Co-Polymersystem EpoCore und EpoClad hergestellt. Diese wurden anschlie��end bez��glich ihrer Temperatur- und Polarisationsabh��ngikeit sowie ihrer Transmissivit��t untersucht. Die AWG wurden f��r eine Mittenwellenl��nge von �� = 850 nm konstruiert und besitzen einen Kanalabstand von ���� = 1 nm sowie einer Halbwertsbreite von FWHM = 1 nm beziehungsweise 0,7 nm. Abschlie��end konnte mit dem Vermessen mehrerer Lade- und Entladezyklen eines Lithium-Ionen-Akkumulators eine m��gliche Anwendung f��r das Polymer-AWG erfolgreich demonstriert werden., In the present dissertation the feasibility of a polymer optical evaluation unit using direct laser lithography is shown. This work addresses not only the simulation but also the production, characterization and evaluation of arrayed waveguide gratings(AWGs), made exclusively from polymers. AWGs are integrated optical demultiplexer structures and are used in this work for the detection of optical wavelength shifts. Specifically, the production of AWGs using direct laser lithography is discussed. The majority of AWGs currently available on the market are made from silicon or other semiconductor materials. The manufacture of such inorganic components is complex, requires numerous process steps under clean room conditions and therefore very expensive. Polymers offer a costeffective alternative to inorganic materials, as they are much cheaper to purchase, easier to process and therefore more cost-effective to produce. In this work, a polymer AWG is presented for the first time, which was produced exclusively by direct laser lithography. This maskless lithography method is highly flexible, which makes this process particularly suitable for applications in the field of development and research or in the production of small series. Changes to the AWG design can be made by a simple and inexpensive change of the design file. As soon as the optimal design with the desired functionality has been found, the process can be easily converted to another method with higher throughput due to its inherent similarity to mask-based lithography methods. In addition to the extensive simulations to find the ideal dimensions of the AWG, taking into consideration the applied manufacturing method and parameters of the materials processed, extensive studies were carried out to find suitable parameters for the utilized lithography system. Based on these results, AWGs with 3 and 16 output channels were produced on a cycloolefin-Copolymer or polyimide substrate with the polymer system EpoCore and EpoClad. The structures were examined with regard to their temperature and polarization dependency as well as their transmission function. The AWGs were designed for a center wavelength of �� = 850 nm and have a channel spacing of ���� = 1 nm and a half width of FWHM = 1 nm or 0.7 nm. Lastly, by measuring several charge and discharge cycles of a lithium-ion battery, a possible application of the polymer AWG was successfully demonstrated.

Integrierte optische Schaltkreise dienen zur Lichtleitung auf Halbleiterchips und ermöglichen die Miniaturisierung allgemeiner optischer Experimente. Dabei kann die passive Materialplattform erweitert werden, indem zusätzliche Elemente über das evaneszente Feld an einen Wellenleiter gekoppelt werden. Dieser Kopplungsmechanismus wurde ausgenutzt, um einen thermischen Rubidium-Atomdampf an Siliziumnitrid-Wellenleiter anzubinden. Die Wechselwirkung wurde durch die Aufnahme von Absorptionsspektren sowie durch die Bestimmung der induzierten Phasenverschiebung im sichtbaren Spektralbereich umfassend charakterisiert. Neben der Kopplung an Atome spielt insbesondere die Aufnahme von Molekülspektren eine bedeutende Rolle, um chemische Analysen unbekannter Substanzen durchzuführen. Da diese Spektren im langwelligen Infrarotbereich liegen bedarf es einer Weiterentwicklung bisher bestehender Materialplattformen. So wurden erstmals integrierte Strukturen aus Silizium und Diamant verwendet um Lichtleitung auf einem Chip bei einer Wellenlänge von 8 µm zu realisieren. Integrated optical circuits are used for light guiding on semiconducting chips and enable the miniaturization of optical experiments on a robust platform. However, the basic material system has to be extended in order to fulfill the specific requirements of complex systems. This can be achieved by hybrid systems, which are based on the evanescent coupling to an additional element. In this way a thermal rubidium atom vapor was coupled to silicon nitride waveguides. The interaction was characterized by recording absorption spectra of the D2 line in the visible spectral regime and by determining the simultaneously induced phase shift. Besides the light-atom interaction, the coupling to molecules is most important for general chemical analyses of unknown substances. The molecular vibrations and the corresponding absorption spectra are located in the long-wavelength infrared regime. Therefore, advanced silicon and diamond circuits were developed and transmission measurements through these structures were demonstrated for the very first time at a wavelength of 8 µm.

This work investigates the possibilities of functional integration for reflective optics that are manufactured via Selective Laser Melting. A method for identifying a broad range of technical functions and concepts that are suitable for functional integration is presented. Using a flashlight and a bicycle headlamp, selected concepts are realized.

Silicon-organic hybrid (SOH) modulators add a highly efficient nonlinear organic electro-optic cladding material to the silicon photonic platform, thereby enabling efficient electro-optic modulation. In this book, the application potential of SOH modulators is investigated. Proof-of-principle experiments show that they can be used for high-speed communications at symbol rates up to 100 GBd and operated directly from a field-programmable gate array (FPGA) without additional driver amplifiers.

Optical studies of single emitters have become routine for a number of systems ranging from atoms and ions in the gas phase to molecules, color centers and quantum dots in the solid-state. A new direction in experimental quantum optics is to exploit this know-how to assemble well-defined arrangements of optically coupled emitters for investigating quantum many-body physics. However, common approaches via strong focusing or cavity quantum electrodynamics do not scale favorably. We developed a scalable light-matter interface by coupling organic dye molecules to subwavelength dielectric waveguides (nanoguides). Their small effective mode area gives rise to substantial single-emitter coupling efficiencies with expected values up to 35%. By combining high-resolution microscopy with fluorescence excitation and resonance fluorescence spectroscopy, we study the coupled nano-guide-emitter system. Our results demonstrate the versatility of the geometry for reaching high optical densities and yet maintaining the addressability of each single emitter. We show that we can couple several thousand molecules simultaneously and coherently to a single guided mode, while their nearly lifetime-limited resonances are inhomogeneously distributed. The optical response of the coupled nanoguide-emitter system can be controlled by modifying the molecular electronic states either via static electric or external optical fields. Here, a pump beam can switch and even coherently amplify a weak laser beam that probes the inherent nonlinearity of a single molecule. Moreover, we gain local control of the molecular resonance frequencies via the dc Stark effect by applying static electric fields on microelectrodes integrated along our chip-compatible nanoguides. Exploiting this tunability allows us to match the resonance frequencies of two molecules that are coherently coupled to the same waveguide mode. All these crucial ingredients, a scalable light-matter interface, high optical densities, external control over the molecular resonance frequencies and their nonlinear response, open up realistic prospects for investigating small, but well-defined networks of quantum emitters coherently coupled via a shared guided mode. Optische Studien an einzelnen Emittern sind für eine Vielzahl von Systemen, wie Atomen oder Ionen in der Gasphase bis hin zu Molekülen, Farbzentren und Quantenpunkten im Festkörper, zur Routine geworden. Ein neuer Forschungszweig in der experimentellen Quantenoptik versucht dieses Wissen zu nutzen, um Emitter kontrolliert optisch miteinander zu verknüpfen. Die resultierenden Quantennetzwerke können genutzt werden, um kooperative Effekte in Vielteilchensystemen zu untersuchen. Die herkömmlichen Herangehensweisen, wie zum Beispiel starkes Fokussieren von Licht oder Hohlraum- Quantenelektrodynamik, ermöglichen zwar eine effiziente Wechselwirkung mit einzelnen Emittern, sind jedoch nicht skalierbar. In dieser Arbeit präsentieren wir einen skalierbaren Ansatz, der die effiziente Wechselwirkung der geführten Mode eines dielektrischen Wellenleitersmit organischen Farbstoffmolekülen ausnutzt. Durch die kleine effektive Modenfläche der Wellenleiter erwarten wir Kopplungseffizienzen bis hin zu 35%. Farbstoffmoleküle können sich bei Temperaturen von superfluidem Helium wie ein nahezu ideales Zwei-Niveau-System verhalten. Dies führt zu einem großen optischen Streuquerschnitt, der für kohärente Licht-Materie Wechselwirkung nötig ist. Wir untersuchen die Kopplung von einzelnen Molekülen an unsere Wellenleiter mithilfe von hochauflösender Mikroskopie sowie Methoden der Fluoreszenzanregungs- und Resonanzfluoreszenz-Spektroskopie. Unsere Plattformerlaubt es, mehrere tausend Moleküle kohärent an einen Wellenleiter zu koppeln. Die spektral verteilten, molekularen Resonanzen zeigen eine Linienbreite, die durch die Lebensdauer der elektronischen Zustände begrenzt ist. Das optische Verhalten des gekoppelten Molekül-Wellenleitersystems kann mithilfe von statisch elektrischen oder externen optischen Feldern gesteuert werden, da diese die elektronischen Zustände der Moleküle beeinflussen. Wir zeigen, dass durch die Nichtlinearität eines einzelnen Moleküls ein starkes Lichtfeld einen zweiten, schwachen Laserstrahl schalten oder sogar kohärent verstärken kann. Darüber hinaus können durch das Anlegen statisch elektrischer Felder die Resonanzfrequenzen derMoleküle verschoben werden (Stark Effekt). Dies erlaubt es uns, die Resonanzen von zwei Molekülen gezielt zu überlagern, die kohärent an den gleichen Wellenleiter koppeln.

Optical studies of single emitters have become routine for a number of systems ranging from atoms and ions in the gas phase to molecules, color centers and quantum dots in the solid-state. A new direction in experimental quantum optics is to exploit this know-how to assemble well-defined arrangements of optically coupled emitters for investigating quantum many-body physics. However, common approaches via strong focusing or cavity quantum electrodynamics do not scale favorably. We developed a scalable light-matter interface by coupling organic dye molecules to subwavelength dielectric waveguides (nanoguides). Their small effective mode area gives rise to substantial single-emitter coupling efficiencies with expected values up to 35%. By combining high-resolution microscopy with fluorescence excitation and resonance fluorescence spectroscopy, we study the coupled nano-guide-emitter system. Our results demonstrate the versatility of the geometry for reaching high optical densities and yet maintaining the addressability of each single emitter. We show that we can couple several thousand molecules simultaneously and coherently to a single guided mode, while their nearly lifetime-limited resonances are inhomogeneously distributed. The optical response of the coupled nanoguide-emitter system can be controlled by modifying the molecular electronic states either via static electric or external optical fields. Here, a pump beam can switch and even coherently amplify a weak laser beam that probes the inherent nonlinearity of a single molecule. Moreover, we gain local control of the molecular resonance frequencies via the dc Stark effect by applying static electric fields on microelectrodes integrated along our chip-compatible nanoguides. Exploiting this tunability allows us to match the resonance frequencies of two molecules that are coherently coupled to the same waveguide mode. All these crucial ingredients, a scalable light-matter interface, high optical densities, external control over the molecular resonance frequencies and their nonlinear response, open up realistic prospects for investigating small, but well-defined networks of quantum emitters coherently coupled via a shared guided mode., Optische Studien an einzelnen Emittern sind für eine Vielzahl von Systemen, wie Atomen oder Ionen in der Gasphase bis hin zu Molekülen, Farbzentren und Quantenpunkten im Festkörper, zur Routine geworden. Ein neuer Forschungszweig in der experimentellen Quantenoptik versucht dieses Wissen zu nutzen, um Emitter kontrolliert optisch miteinander zu verknüpfen. Die resultierenden Quantennetzwerke können genutzt werden, um kooperative Effekte in Vielteilchensystemen zu untersuchen. Die herkömmlichen Herangehensweisen, wie zum Beispiel starkes Fokussieren von Licht oder Hohlraum- Quantenelektrodynamik, ermöglichen zwar eine effiziente Wechselwirkung mit einzelnen Emittern, sind jedoch nicht skalierbar. In dieser Arbeit präsentieren wir einen skalierbaren Ansatz, der die effiziente Wechselwirkung der geführten Mode eines dielektrischen Wellenleitersmit organischen Farbstoffmolekülen ausnutzt. Durch die kleine effektive Modenfläche der Wellenleiter erwarten wir Kopplungseffizienzen bis hin zu 35%. Farbstoffmoleküle können sich bei Temperaturen von superfluidem Helium wie ein nahezu ideales Zwei-Niveau-System verhalten. Dies führt zu einem großen optischen Streuquerschnitt, der für kohärente Licht-Materie Wechselwirkung nötig ist. Wir untersuchen die Kopplung von einzelnen Molekülen an unsere Wellenleiter mithilfe von hochauflösender Mikroskopie sowie Methoden der Fluoreszenzanregungs- und Resonanzfluoreszenz-Spektroskopie. Unsere Plattformerlaubt es, mehrere tausend Moleküle kohärent an einen Wellenleiter zu koppeln. Die spektral verteilten, molekularen Resonanzen zeigen eine Linienbreite, die durch die Lebensdauer der elektronischen Zustände begrenzt ist. Das optische Verhalten des gekoppelten Molekül-Wellenleitersystems kann mithilfe von statisch elektrischen oder externen optischen Feldern gesteuert werden, da diese die elektronischen Zustände der Moleküle beeinflussen. Wir zeigen, dass durch die Nichtlinearität eines einzelnen Moleküls ein starkes Lichtfeld einen zweiten, schwachen Laserstrahl schalten oder sogar kohärent verstärken kann. Darüber hinaus können durch das Anlegen statisch elektrischer Felder die Resonanzfrequenzen derMoleküle verschoben werden (Stark Effekt). Dies erlaubt es uns, die Resonanzen von zwei Molekülen gezielt zu überlagern, die kohärent an den gleichen Wellenleiter koppeln., FAU Studies Mathematics and Physics (11)

Modern quantum technology currently experiences extensive advances in applicability in communications, cryptography, computing, metrology and lithography. Harnessing this technology platform for chem/bio sensing scenarios is an appealing opportunity enabling ultra-sensitive detection schemes. This is further facilliated by the progress in fabrication, miniaturization and integration of visible and infrared quantum photonics. Especially, the combination of efficient single- photon sources together with waveguiding/sensing structures, serving as active optical transducer, as well as advanced detector materials is promising integrated quantum photonic chem/bio sensors. Besides the intrinsic molecular selectivity and non-destructive character of visible and infrared light based sensing schemes, chem/bio sensors taking advantage of non-classical light sources promise sensitivities beyond the standard quantum limit. In the present review, recent achievements towards on-chip chem/bio quantum photonic sensing platforms based on N00N states are discussed along with appropriate recognition chemistries, facilitating the detection of relevant (bio)analytes at ultra-trace concentration levels. After evaluating recent developments in this field, a perspective for a potentially promising sensor testbed is discussed for reaching integrated quantum sensing with two fiber-coupled GaAs chips together with semiconductor quantum dots serving as single-photon sources, acceptedVersion

[no abstract]

Following the intensive development of isolated (i.e., not coupled with on-chip waveguide) vertically rolled-up microtube ring resonators (VRU-MRRs) for both active and passive applications, a variety of microtube-based devices has been realized. These include microcavity lasers, optical sensors, directional couplers, and active elements in lab-on-a-chip devices. To provide more advanced and complex functionality, the focus of tubular geometry research is now shifting toward (i) refined vertical light transfer in 3D stacks of multiple photonic layers and (ii) to make microfluidic cooling system in the integrated optoelectronic system. Based on this motivation, this PhD research is devoted to the demonstration and the implementation of monolithic integration of VRU-MRRs with photonic waveguides for 3D photonic integration and their optofluidic applications. Prior to integration, high-quality isolated VRU-MRRs on the flat Si substrate are firstly fabricated by the controlled release of differentially strained titanium-dioxide (TiO2) bilayered nanomembranes. The fabricated microtubes support resonance modes for both telecom and visible photonics. The outcome of the isolated VRU-MRRs is a record high Q (≈3.8×10^3) in the telecom wavelength range with optimum tapered optical fiber resonator interaction. To further study the optical modes in the visible and near infrared spectral range, μPL spectroscopy is performed on the isolated VRU-MRRs, which are activated by entrapping various sizes of luminescent nanoparticles (NPs) within the windings of rolled-up nanomembranes based on a flexible, robust and economical method. Moreover, it is realized for the first time, in addition to serving as light sources that NPs-aggregated in isolated VRU-MRRs can produce an optical potential well that can be used to trap optical resonant modes. After achieving all the required parameters for creating a high-quality TiO2 VRU-MRR, the monolithic integration of VRU-MRRs with Si nanophotonic waveguides is experimentally demonstrated, exhibiting a significant step toward 3D photonic integration. The on-chip integration is realized by rolling up 2D pre-strained TiO2 nanomembranes into 3D VRU-MRRs on a microchip which seamlessly expanded over several integrated waveguides. In this intriguing vertical transmission configuration, resonant filtering of optical signals at telecom wavelengths is demonstrated based on ultra-smooth and subwavelength thick-walled VRU-MRRs. Finally, to illustrate the usefulness of the fully integrated VRU-MRRs with photonic waveguides, optofluidic functionalities of the integrated system is investigated. In this work, two methods are performed to explore optofluidic applications of the integrated system. First, the hollow core of an integrated VRU-MRR is uniquely filled with a liquid solution (purified water) by setting one end of the VRU-MRRs in contact with a droplet placed onto the photonic chip via a glass capillary. Second, the outside of an integrated VRU-MRR is fully covered with a big droplet of liquid. Both techniques lead to a significant shift in the WGMs (Δλ≈46 nm). A maximum sensitivity of 140 nm/refractive index unit, is achieved. The achievements of this PhD research open up fascinating opportunities for the realization of massively parallel optofluidic microsystems with more functionality and flexibility for analysis of biomaterials in lab-on-a-tube systems on single chips. It also demonstrates 3D photonic integration in which optical interconnects between multiple photonic layers are required.

eingereicht von: Irina Hinterlechner Kurzfassung in dt. und engl. Sprache Linz, Univ., Master-Arb., 2015

In this book, silicon photonic integrated circuits are combined with electro-optic organic materials for realizing energy-efficient modulators with unprecedented performance. These silicon-organic hybrid Mach-Zehnder modulators feature a compact size, sub-Volt drive voltages, and they support data rates up to 84 Gbit/s. In addition, a wet chemical waveguide fabrication scheme and an efficient fiber-chip coupling scheme are presented.

Diese Arbeit beschreibt Messtechniken zur Charakterisierung integriert-optischer Wellenleitersysteme auf Basis der SOI-Technologie. Hierbei lag der Schwerpunkt auf der Bestimmung der Wellenleiterdämpfung sowie der Lebensdauer freier Ladungsträger. Neben einem neuartigen Verfahren zur räumlich aufgelösten Bestimmung der Wellenleiterverluste mittels optischer Frequenzbereichsreflektometrie (OFDR) wird ein experimenteller Nachweis über das nichtreziproke Verhalten der Raman-Streuung in Siliziumwellenleitern gezeigt. Weiterhin wird ein DUV-Lithografieverfahren zur Herstellung periodischer Strukturen in Fotolacken auf Siliziumsubstraten vorgestellt, das auf der Verwendung von Beugungsgittern basiert., In this work, measurement techniques for the characterization of integrated optical waveguides based on the SOI-technology are presented. Silicon nanophotonic waveguides are investigated regarding their linear waveguide losses as well as the lifetime of free charge carriers. A novel measurement technique based on optical frequency-domain reflectometry (OFDR) for the evaluation of the longitudinal attenuation profile of silicon waveguides is introduced. The non-reciprocal behaviour of Raman scattering in silicon waveguides is experimentally shown. Furthermore, a technique for the implementation of periodically structured photoresists on silicon substrates based on DUV-lithography with diffraction gratings is demonstrated.

The subject of this dissertation is the investigation of optical waveguides in crystals written with ultrashort laser pulses. The writing process of light guiding structures in Pr:YLiF4 and Al2O3 is analysed and optimized. Laser induced modifications, which lead to a stress-induced enhancement of the refractive index and thus being the basic mechanism of waveguiding, are identified in the irradiated volume. Furthermore the transfer of the waveguide writing to high velocities is demonstrated. This reduces the process time significantly. A high precision scanner for beam deflection is utilized to fabricate waveguides with arbitrary cladding geometry. The developed process allows fast and individual writing of waveguides, which can be used for applications in integrated optical devices. Beam shaping of laser diode radiation is demonstrated with this scanner written waveguides.

In a recent publication (1), we showed that acoustooptic TE-TM mode conversion in LiNbOsub3, in the 0.8 mym optical wavelength range, can be very efficient. Only 20 m W RF power was necessary to achieve more than 90 percent conversion efficiency for planar propagating surface acoustic waves (SAW). In addition, a very narrow bandwidth was obtained. The 0.8 mym optical wavelength range is especially interesting for several sensor applications. Recently, we have developed a two-layer structure in LiNbOsub3 for refractive index sensing applications (2) consisting of a Ti-indiffused channel waveguide on top of which a thin proton-exchanged (PE) layer is fabricated. In the latter the sign of the optical birefringence is reserved compared with the bulk (and Ti-indiffused) crystal owing to a large increase of the extraordinary and a small decrease of the ordinary refractive index (3). As a result, the fundamental extraordinary mode of this structure becomes highly sensitive to refractive index changes in the superstrate, whereas the ordinary mode is a factor of 10high3 less sensitive (2). This allows the application of a new acoustooptic sensing principle (4), making use of the change of the waveguide birefrigence that results from a change of the superstrate refractive index. The waveguide birefringence can be detected with an acoustooptic TE-TM mode converter since the SAW phase-matching frequency is proportional to it. In this way the SAW frequency becomes a measure of the (absolute) refractive index of the superstrate. The acoustooptic sensing principle is especially suitable for gas sensing applications. Having this idea in mind we investigated collinear acoustooptic TE-TM mode conversion in the two-layer structure. We have obtained efficient narrowband mode converters well suited for sensor applications.

Über einen chemischen Syntheseprozeß (Sol-Gel-Prozeß) können organische-anorganische Verbundwerkstoffe hergestellt werden, die eine Vielzahl von für die Integrierte Optik interessanten Eigenschaften aufweisen. Neben einfachem Processing besitzen diese Materialien sehr gute optische Eigenschaften und können mit optisch nichtlinearen Komponenten dotiert werden. Dieser Beitrag soll dazu dienen, diese Materialklasse und ihr Potenzial in der Integrierten Optik vorzustellen.

Waveguides for optical radiation and nanostructures are essential for new and future optical technologies. The generation of waveguides with femtosecond laser radiation by moving a focus is exemplarily demonstrated with longitudinaly written volume waveguides and ridge waveguides in thin films. Combining element of both waveguide types are periodic subwavelength structures on the surface (ripples, germ. Riffel, also laser induced periodical surface structures (LIPSS)) and in the volume (nanoplanes). The subwavelength ripples emerging at ablation with ultra short pulsed laser radiation are investigated in-depth in theory and experiments as well as their influence on the structure precision and their analogy with nanoplanes. The volume waveguides in fused silica (length 9mm, diameter 1-5µm) are homogeneous and continuous at fluences below ~5kJ/cm³. Homogeneous monomode waveguides with a refractive index change Delta-n up to 2.8*10^(-4) and a damping below 2dB/cm are demonstrated. The generation of surface ridge waveguides (pulse duration t=100fs, wavelenth l=800nm and 400nm, NA 0,55, width 100µm in a 1µm thick thin film of Er:ZBLAN on magnesium fluoride) are demonstrated. Due to ripples the orientation of the polarisation is essential. The achieved smoothness of the edges is 100-300nm at a grove depth up to 1.8µm. A damping below 5dB/cm is demonstrated and the possibility of a damping below 1dB/cm is indicated. To complement the established models for classical ripples for the explanation of subwavelength ripples at pulse durations below a few nanoseconds some valuations are made such as the influence of longitudinal fields at tight focusing, near field scattering including resulting field enhancements and the significance of surface plasmons. For the first time it is suggested that for the modelling of the ripple spacing the dynamic variation of the dielectric function during the irradiation has to be taken into account. From the surface plasmon model constraints are elaborated for the real and imaginary part of the complex dielectric function of the material during the irradiation, under which ripples develop at domination of polaritons. To understand the initial becoming of the ripples a seed model is suggested, which is evaluated on the basis of the experimental results. The analogy between subwavelenth ripples on the surface and nanoplanes in the volume are discussed in relation to their phenomenology and a common model to explain their development. The experimental investiagtions of the subwavelenth ripples in this work give a contribution to the phenomenological description and the comprehension of the subwavelength ripples. Investigated variations are: wavelength l=800nm, 532nm, 400nm and 266nm, linear und circular polarisation, repition rate between f=1kHz und 1Hz, lateral pulse spacing, pulse energy, the surface morphology before the irradiation and the pulse duration between t=80fs and 40ps. Investigated materials are: gold, copper, Silicon, lithium niobate, zirconium oxide, diamond, fused silica, sapphire, magnesium fluoride, lithium fluoride, ZBLAN, PTFE, human hair. The ripples are orientated perpendicular to the polarisation of the laser radiation and are coherently expanded at moving the focus. For the generation of grids this also is possible in two dimensions. The ripples predominantly evolve from ablation and not from relocation of material. The ripple spacing L depends on the material and the wavelength l. At l=800nm it was measured: dielectrics L=190 to 330nm (L/l=0.24 to 0.41), metals and semiconductors L=500 to 600nm (L/l=0.63 to 0.75). The ripple spacing gets smaller with the wavelength. The ratio L/l for l=400nm is bigger for dielectrics and silicon than at l=800nm. After five pulses the typical characteristics of ripples are accomplished. A surface structure, e.g. due to a previous pulse or a shallow scratch about perpendicular to the radiation promote the development of ripples. In silicon directly below the ablation threshold a lateral periodic modification of the density is observed. This has a periodicity comparable with the ripple spacing of silicon, indicating that Nanoplanes and subwavelenth ripples probably can be ascribed to the same principles, which is consistent with the suggested seed model. At a focus movement parallel to the polarisation “detached ripples” with their closest neighbour more than two focus diameters away are observed for the first time. Detached ripples can not be explained by the established models, but by the combined subwavelenght/nanoplanes model.

An algorithm for the calculation of the propagation constant of integrated-optics waveguides is developed. The waveguide may consist of any number of layers with complex refractive indexes due to gain and loss. It allows the additional determination of the field distribution. Thus, all parameters necessary for heterostructure laser development can be calculated. The resulting program was run on a personal computer; numerical results are presented. >

High index-contrast nanophotonic devices are key components for future board-to-board and chip-to-chip optical interconnects: The strong confinement of light enables dense integration, and nonlinear effects can be exploited at low power levels. Cheap large-scale production is possible by using highly parallel microfabrication techniques, and semiconductor-based nanophotonic devices can be integrated together with electronic circuitry on a common chip. Particularly intense research is carried out to realise optical devices on silicon substrates, using mature complementary metal-oxide-semiconductor (CMOS) fabrication techniques. This book discusses the modelling, fabrication and characterization of linear and nonlinear nanophotonic devices. Roughness-related scattering loss in high index-contrast waveguides is investigated both theoretically and experimentally, and methods of loss reduction are developed. Novel silicon-based devices for electro-optic modulation and for all-optical signal processing are presented. Nonlinear dynamics in active quantum-dot devices are studied, and resonant field enhancement is exploited to improve the efficiency of nonlinear interaction.

Die Habilitationsschrift gliedert sich in zwei Teile. Teil 1 beschäftigt sich mit der Laserablation von magentooptisch aktiven Materialien. Hierbei werden vor allem Wachstumsstudien des Materials Y3F5O12,Bi3Fe5O12 und LuBiFeO auf Gd3Ga5O12 und SiO Substraten vorgestellt. Im zweiten Teil der Arbeit werden die deponierten Materialien verwendet, um magnetooptische Untersuchungen des Flusseindringens in Supraleiter (MgB2 und YBa2Cu2O12) im Falle einer externen Hochfrequenz und unter Einfluss von akustischen Oberflächenwellen durchzuführen. Dabei wird auch auf selbst organisierte kritische Systeme eingegangen. This report is divided in two parts. Part 1 deals with pulsed laser deposition of magnetooptical active materials. Especially growth mechanism of Y3F5O12,Bi3Fe5O12 and LuBiFeO on Gd3Ga5O12 and SiO is discussed. The second part reports on magnetooptical investigations of superconductors (MgB2 and YBa2Cu2O12) using magnetooptical active materials. Thereby flux penetration is investigated under influence of radio frequency signals and surface acoustic waves. Flux distribution is discussed in terms of a self organised critical system.

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Mit der Integrierten Optik wird das Ziel verfolgt, optische Bauelemente, wie z.B. Filter, Verstärker, Lichtablenker und -modulatoren zu miniaturisieren und auf einem gemeinsamen Trägermaterial zu integriert optischen Schaltkreisen (IOCs) zu kombinieren. Die dafür erforderlichen Technologien ähneln denen der Mikroelektronik (Dünnschichttechniken, Mikrolithographie, Diffusion, Pigtailing). Anwendungsmöglichkeiten integriert optischer Bauelemente und Schaltkreise ergeben sich vor allem im Telekommunikationsbereich, bei der optischen Datenverarbeitung und in der Sensorik.

Für eine stärkere Verbreitung der optischen Informationstechnik werden optische Wellenleiterkomponenten benötigt, die u.a. die Signale optisch schalten und aufsplitten können. Dazu ist die sogenannte SIGA-Technik entwickelt worden, mit der polymere, integriert optische Mikrostrukturen mittels kostengünstiger Replikationstechniken hergestellt werden können.In dieser Arbeit wird dabei auf die Replikationstechniken im Rahmen der SIGA-Technik näher eingegangen. Dazu werden die beiden eingesetzten Abformverfahren des Spritzgießens und Heißprägens dargestellt, mit den Randbedingungen für Mikrostrukturen im allgemeinen und integriert optische Mikrostrukturen im speziellen.Das für integriert optische Mikrostrukturen entwickelte modifizierte Mikrospritzprägen wird ausführlich erläutert, wobei auf die speziellen Werkzeuge, das verwendete Equipment und die damit durchgeführten Prozesse näher eingegangen wird.Das zweite Abformverfahren, das Heißprägen, wird hauptsächlich als Laboranwendung für Prototypen eingesetzt, aber zunehmend auch bei bestimmten empfindlichen Strukturen und besonderen Geometrien, dargestellt am Beispiel einer optischen Rückwand, die über ihre gesamte Länge (10 bis 50 Zentimeter) integriert optische Mikrostrukturen enthält.Ausführlich wird auf Optimierungsmöglichkeiten für die Abformung von Mikrostrukturen eingegangen.Anwendungsbeispiele, vornehmlich aus dem Bereich der optischen Informationstechnik, aber auch aus der Mikrofluidik, demonstrieren das Einsatzpotential der Mikroabformtechnik., To ensure a wider spreading of optical IT optical waveguides are necessary to switch and split optical signals. Therefore the so called SIGA-technique has been developed for manufacturing polymeric, integrated optical microstructures with low-cost replication techniques.Within this thesis the attention is directed towards the replication techniques as part of the SIGA technique. The two used moulding techniques as injection moulding and hot embossing are described putting up marginal conditions for microstructures in general and integrated optical microstructures in particular.The modified micro injection moulding developed especially for integrated optical microstructures is explained in detail. Close attention is given to the special tools, the used equipment and the processes carried out.The second moulding technique, hot embossing, is usually applied as a lab technique for prototypes, but more and more for difficult structures with special geometries, too, shown by the example of an optical backplane. This backplane, which is several centimetres long (10 to 50 cm), has integrated optical microstructures over its complete length.The optimization for replication of microstructures is described in detail.Application examples, especially from optical information technique, but also from micro fluidics, demonstrate the high potential of micro moulding / micro replication techniques.

Optische Wellenleiterkomponenten sind Schlüsselbausteine der optischen Datenübertragungstechnik. Die Herstellung dieser Komponenten auf Basis polymerer Werkstoffe eröffnet die theoretische Möglichkeit zur kostengünstigen Massenfertigung. Im Rahmen dieser Arbeit werden die wesentlichen Abhängigkeiten der optischen Dämpfung passiver integriert einmodiger Polymerwellenleiter sowohl von den strukturellen Eigenschaften der verwendeten Materialien als auch von den technologischen Rahmenbedingungen der Wellenleiterherstellung aufgeklärt. Die Wellenleiterherstellung beruht auf dem sogenannten SIGA-Verfahren. Hier wird die Rauheit der Wellenleiterstrukturen als Hauptfehlerquelle detektiert und der Einfluß auf die Wellenleiterdämpfung theoretisch quantifiziert. Die Eignung verschiedener Copolymersysteme, basierend sowohl auf halogenierten Acrylaten als auch auf halogenierten Polylactonen, für die Verwendung in optischen Wellenleitern wird untersucht. Ein Schwerpunkt dieser Untersuchungen ist u.a. die Visualisierung der chemischen Zusammensetzung der Copolymere im Wellenleiter mittels der Transmissionselektronenmikroskopie. Für die Dämpfung in dB der untersuchten Wellenleitermaterialien im Nahen Infrarot wird eine lineare Abhängigkeit von der C-H-Bindungskonzentration der verwendeten Polymere gefunden., Optical waveguide components are key elements in the optical telecommunication technology. These components may be theoretically fabricated very cost effective using polymers. In this work the optical loss of polymer waveguides is examined as a function of the material structure and also in dependance on the waveguide fabrication technology. The polymer waveguides are fabricated using the so-called SIGA-technology. Surface roughness of the waveguides is determined as a main source for optical waveguide losses, which is theoretically calculated. Several copolymers consisting of halogenated acrylates and halogenated lactones are examined with respect to their applicability in optical waveguides. To determine the chemical composition in the waveguides transmission electron microscopy is used, for example. The optical loss in dB of the waveguide polymers in the near infrared region shows a linear dependance on the C-H-bond concentration in the polymers.

UV-curable epoxy based adhesive was filled with nansize SiO2-particles with particle diameters of about 10 nm (SiO2-content in the composite adhesives up to 35 wt.-%). Viscosities of the filled uncured adhesives were kept low at about 1000 mPa-s to 2000 mPa-s by surface modification of the particles. Volume shrinkage rate was reduced from 5.0% (unfilled system) to 3.6 % in the case of a composite material with 20 wt.-% (approx. 12 vol.-%) nanosized SiO2. Hence the coefficient of thermal expansion in a temperature range from -50°C to 100°C, was reduced from 70.10(-6) K-1 to 57.10(-6) K-1. The refractive index decreased from 1.525 to 1.514 at a wavelength of 644 nm. Transmission electron microscopy (TEM) investigations demonstrate that the nanosized SiO2-particles are not agglomerated in the cured material.

New transparent UV-curable adhesives for the use in integrated optics based on organic-inorganic nanocomposites (NANOMER) have been developed. These adhesives show excellent optical properties, whereby a high content of SiO2 particles with an average particle size of 10 nm can be achieved (up to 35 vol-%). The thermal expansion coefficient could be reduced from 75 ppm/K down to 30 ppm/K with a filler content of 20 wt-% (15 vol-%). The refractive index could be varied from 1.450 (cured 1.461) to 1.546 (cured 1.558), at a wavelength of 644 nm, by variation of the synthesis. UV-curing was faster compared to UV-curable commercial epoxy resins.

In this paper a refractometer system with an integrated optical sensor is presented. The sensitive element is a single or multichannel Mach-Zehnder interferometer (MZI) fabricated on silicon using waveguides made from SiO2, and SiON. The refractometer allows for real time monitoring of refractive indices of gases and liquids in an index range between 1 and 1,49 using the silicon MZI as a low cost consumable part.

An important prerequisite for large-scale industrial use of new microsystems with micromechanical, microelectrical and microoptical components is possibility of low-cost production of these systems in large numbers. Replication techniques such an embossing and injection moulding offer this opportunity. In order to assess the prospects and limitation of this technique a device for hot embossing was developed at the Fraunhofer Institution in Jena.

A monomode antiresonant reflecting optical strip waveguide has been realized in SiON/SiO2/Si. The lateral confinement is provided by strip-loaded reflectors fabricated by e-beam direct writing and reactive ion beam etching (RIBE).

A novel waveguide coupler consisting of two antiresonant reflecting optical waveguides in strip-configuration has been developed on Si-SiO2-SiON basis. Remote coupling over a distance of 93 mym has been demonstrated experimentally.

We have developed and investigated a novel two-layer structure in LiNbO3 fabricated with Ti-indiffusion and proton exchange. This structure is especially suitable for constructing refractive-index sensors with a large, up to 2.2, measurement range. Next to its high sensitivity this structure offers also some additional advantages like the possibility to optimize the sensitivity for a given measurand, the elimination of the necessity of buffer layers etc. The largely different sensitivities of the two fundamental TE0- and TM0-modes achieved allows the measurement and the reference channel to be incorporated in the same waveguide. In this way, a new type polarization interferometry can be introduced increasing the flexibility of the refractive-index sensors design.

Die Erfüllung individueller Kundenwünsche im Bereich der optischen Meßtechnik erfordert das Bereitstellen komplexer Systeme mit einem hohen Innovationsgrad. Dabei werden an die eingesetzten Werkstoffe und Baugruppen hohe technische Anforderungen bei engen Toleranzen gestellt. Die Vielfalt der Anforderungsprofile an solche Systeme ist aufgrund sich wandelnder Kundenwünsche ständigen Änderungen unterworfen und erfordert daher eine hohe Flexibilität bei der Fertigung. Bei der Vielfalt der eingesetzten Werkstoffe ist ein systemkonformes flexibel einzusetzendes Fügeverfahren für die Aufbau- und Verbindungstechnik dieser Systeme unabdingbar.

We have experimentally demonstrated the feasibility of a novel integrated acousto-optical gas sensor in LiNbO 3 . Two-layer optical waveguides with increased refractive index sensitivity have been investigated, as well as TE-TM mode converters on these waveguides with low r.f. drive power. These two (optical and acoustic) parts of the proposed sensor show an adequate performance. The possibilities of the incorporation of a reference channel and the fabrication of a multisensor are also discussed.

It is common industrial practice to use adhesives for attaching glass-fibre waveguides to components of fibre- and integrated-optics sensors. Quality assurance in the production of these sensors is, however, still problematic because adhesive systems and processes are not yet fully matured. This article describes an approach to opitmize adhesive systems with respect to thermal and mechanical strength. Four different adhesive systems have been tested mechanically, chemically and optically.

Low power, narrowband integrated acousto-optic TE-TM mode convertors for the 0.8 micrometer optical wavelength range have been developed. Acoustic drive power of less then 10 mW was required for 96 % conversion efficiency. The 0.32 nm optical bandwidth corresponding to the acoustic bandwidth of 138 kHz achieved is the narrowest reported to date for a TE-TM mode convertor.

Signalverarbeitung ist ein weit verzweigtes Gebiet und wesentlicher Bestandteil nahezu aller technischen Einrichtungen. Während in früheren Jahren analoge Signale mit analogen Techniken (Filter, Dioden usw.) bearbeitet wurden, hat sich mit dem Aufkommen der digitalen Halbleiterelektronik die digitale Signalverarbeitung immer mehr durchgesetzt. Die Theorie digitaler Filter und die Anwendung des FFT-Algorithmus wurden insbesondere in den 70er Jahren ausgebaut. Seitdem gibt es zahllose Anwendungen digitaler Signalverarbeitungstechniken. Im gleichen Zeitraum entstanden Arbeiten über optische Signalverarbeitung. Optische Verfahren beruhen auf der Ausbreitung des Lichts und sind daher im Prinzip räumlich zweidimensional ausgedehnt. Diese Parallelität verspricht hohe Rechengeschwindigkeiten und hohen Datendurchsatz. In dieser Kurzexpertise wird ein Überblick über den Stand optischer Signalverarbeitung 1990 gegeben. Zunächst werden die verschiedenen Techniken beschrieben und hinsichtlich mögli cher Anwendungen diskutiert. Den einzelnen Verfahren sind jeweils Schlußfolgerungen bezüglich ihrer Rolle bei der Lösung zukünftiger technischer Probleme zugeordnet. Die Arbeit schließt mit einigen Hinweisen, die für eine Planung zukünftiger Systeme nützlich sein können.