Dissertations / Theses on the topic '621.35.035:621.365'

Диссертация на соискание ученой степени кандидата технических наук по специальности 05.09.13 "Техника сильных электрических и магнитных полей". – Национальный технический университет "Харьковский политехнический институт", Харьков, 2015. В диссертационной работе решена научно-техническая задача усовершенствования высоковольтных импульсных трансформаторов с использованием полупроводниковых коммутаторов для электрофизических установок, что позволило модернизировать существующие и создать новые электротехнологические установки, создающие сильные импульсные электрические и магнитные поля. Разработанная двухступенчатая схема мегавольтного генератора импульсов напряжения с использование двух импульсных трансформаторов позволила создать компактный трансформаторный импульсный источник напряжения с временем нарастания импульсов ≈250 нс на емкостной нагрузке ≈1 нФ и напряжением до 1 МВ. Установлено, что для созданных высоковольтных импульсных трансформаторов на напряжение 100 кВ и 1 МВ для импульсного мегавольтного генератора путем усовершенствования высоковольтных импульсных трансформаторов состоящего в том, что части как вторичной так и первичной обмотки разнесены и расположены не на одном общем стержне, а на четырех крестообразно расположенных частях расщепленного стержня магнитопровода, удалось уменьшить результирующую индуктивность рассеивания этих трансформаторов. Исследованы безаварийные рациональные режимы работы в импульсных трансформаторах с полупроводниковыми коммутаторами в генераторах для получения ИКР. Установлено, что при работе полупроводникового ключа в качестве размыкающего коммутатора амплитуда напряжения на реакторе Up может существенно превышать удвоенное зарядное напряжение первичной накопительной ёмкости, умноженное на коэффициент трансформации (Up>>2ntU₀), а при работе ключа в качестве замыкающего коммутатора Up не может превышать величины Up = 2 nт U₀, где U₀ – амплитуда зарядного напряжения первичной накопительной ёмкости, nт – коэффициент трансформации. Экспериментальные исследования работы высоковольтного импульсного трансформатора в компактном генераторе высоковольтных импульсов с полупроводниковым ключом показало, что время нарастания напряжения на реакторе до максимума меньше при работе ключа в качестве замыкающего коммутатора, а время нарастания тока на реакторе до максимума меньше при работе ключа в качестве размыкающего коммутатора. Впервые создана и в заводских условиях успешно опробована установка на основе двух импульсных трансформаторов с полупроводниковыми ключами в низковольтной цепи генератора импульсов высокого напряжения для парового риформинга метана в составе коксового газа в синтез-газ при помощи высоковольтных импульсных объёмных разрядов: коронного и барьерного с засыпкой никелевым катализатором.
Dissertation for competition a technical science candidate degree. Speciality 05.09.13. "High electric and magnetic field engineering". National Technical University "Kharkov Polytechnical Institute", Kharkov, 2015. In this work the scientific and practical problem of improvement of high-voltage pulsed transformers with using semiconductor switches for electrophysical plants has been solved which enabled to modernize existing and to create new electrotechnological plants that generate strong pulsed electric and magnetic fields. It was found that improvement of high-voltage transformers, which consist in that the parts of the secondary and primary windings are separated and placed not at one common core but at four crosswise situated parts of split core of magnetic circuit, enabled to reduce a resulting leakage inductance of the transformers. Using them in two-stage circuit of voltage pulse generator enabled to create a compact pulsed voltage source with pulse rise time 250 ns at a capacitive load about 1 nF and voltage of 1 MV. Accident-free rational operation modes of pulsed transformers with semiconductor switches in generators for creating PCD with high pulse repetition frequency have been investigated. For the first time in the factory conditions a plant on the basis of pulsed transformers with semiconductor switches in the circuit of the generator of voltage pulses for steam reforming of methane as part of coke-oven gas into synthesis gas with help of high-voltage pulsed volumetric discharges: corona and barrier discharge with nickel catalyst in the reactor, has been successfully test-operated.

Дисертація на здобуття наукового ступеня кандидата технічних наук за фахом 05.09.13 "Техніка сильних електричних та магнітних полів". – Національний технічний університет "Харківський політехнічний інститут", Харків, 2015. У роботі вирішена науково-практичне задача удосконалення високовольтних імпульсних трансформаторів з використанням напівпровідникових комутаторів для електрофізичних установок, що дозволило модернізувати існуючі та створити нові електротехнологічні установки, які створюють сильні імпульсні електричні та магнітні поля. Встановлено, що удосконалення високовольтних імпульсних трансформаторів яке складається в тому, що частини як вторинної так і первинної обмотки рознесені і розташовані не на одному загальному стрижні, а на чотирьох хрестоподібно розташованих частинах розщепленого стрижня магнітопроводу, дозволило зменшити результуючу індуктивність розсіювання цих трансформаторів. Використання їх у двоступеневій схемі генератора імпульсів напруги дозволило створити компактне імпульсне джерело напруги з часом наростання імпульсів 250 нс на ємнісному навантаженні ~1 нФ і напругою до 1 МВ. Досліджено безаварійні раціональні режими роботи в імпульсних трансформаторах з напівпровідниковими комутаторами в генераторах для отримання ІКР з великою частотою проходження імпульсів. Вперше в заводських умовах успішно апробована установка на основі імпульсних трансформаторів з напівпровідниковими ключами в контурі генератора імпульсів напруги для парового риформінгу метану в складі коксівного газу в синтез-газ за допомогою високовольтних імпульсних об'ємних розрядів: коронного і бар'єрного із нікелевим каталізатором у реакторі.
Dissertation for competition a technical science candidate degree. Speciality 05.09.13. "High electric and magnetic field engineering". National Technical University "Kharkov Polytechnical Institute", Kharkov, 2015. In this work the scientific and practical problem of improvement of high-voltage pulsed transformers with using semiconductor switches for electrophysical plants has been solved which enabled to modernize existing and to create new electrotechnological plants that generate strong pulsed electric and magnetic fields. It was found that improvement of high-voltage transformers, which consist in that the parts of the secondary and primary windings are separated and placed not at one common core but at four crosswise situated parts of split core of magnetic circuit, enabled to reduce a resulting leakage inductance of the transformers. Using them in two-stage circuit of voltage pulse generator enabled to create a compact pulsed voltage source with pulse rise time 250 ns at a capacitive load about 1 nF and voltage of 1 MV. Accident-free rational operation modes of pulsed transformers with semiconductor switches in generators for creating PCD with high pulse repetition frequency have been investigated. For the first time in the factory conditions a plant on the basis of pulsed transformers with semiconductor switches in the circuit of the generator of voltage pulses for steam reforming of methane as part of coke-oven gas into synthesis gas with help of high-voltage pulsed volumetric discharges: corona and barrier discharge with nickel catalyst in the reactor, has been successfully test-operated.

Quantum optics has been a frontier of physics in the last few decades. Integrated quantum photonics which prompts the concept of realizing quantum optics operation on a chip is crucial for any potential applications beyond the optical bench. This thesis focuses on two important material systems (diamond and GaN) which both have the potential for integration of single photon sources and detectors with integrated quantum circuits and at the same time can minimize the footprint of the integrated quantum circuits due to their high refractive index. We have proposed and realized two new masking methods to fabricating higher aspect ratio diamond microlenses through plasma etching. We have also proposed and demonstrated a new approach to fabricating large cross-section edge-coupled rib waveguides on free-standing thin diamond substrates by combining inkjet printing of photoresist with photolithographic patterning technique. Single-mode GaN directional couplers with transmission varying between 0.1:0.9 and 0.55:0.49 have been studied and two-photon interference was demonstrated in a 0.55:0.45 GaN directional coupler. This is the first demonstration of two-photon interference realized on a compound semiconductor chip. Our work opens up a new way to achieve sophisticated integrated quantum photonic circuits based on GaN and other suitable compound semiconductors. Integrated quantum photonics is a widespread research topic, currently undergoing explosive developments. Future options including an all-diamond platform, III-V semiconductors or a hybrid system between diamond and III- V semiconductors are discussed as perspectives.

Photonics is revolutionising the way we live in a similar way to what electronics historically did. The main aim of this PhD project was to investigate and develop fabrication techniques leading to the realisation of mid-infrared photonic components based entirely on chalcogenide glass compositions which were prepared in-house, here at the University of Nottingham, Nottingham, UK. Chalcogenide glasses are based on the chalcogen elements of Group XVI of the Periodic Table and were chosen over conventional silica glass in the work described in this thesis for their significant advantages such as: a wide transmission window, for wavelengths of light from O .5 ~tm up to 25~tm depending on the glass composition, low phonon energies, high non-linearities and high refractive indices. The chalcogenide glass systems of As-Se, Ge-As-Se and Te-As-Se were synthesised and a new quenching technique was developed to prevent ampoule failures. In addition, the distillation of Te-As-Se system was optimised via the use of temperature monitoring. Two simulations were developed using commercial software; the first led to a large mode area, endlessly single mode microstructured optical fibre design and the second verified the photonic band gaps of a photonic band gap fibre from the literature. In particular, a methodology leading to the automation of chalcogenide glass cane drawing, a hot-collapse rig for investigating hot-collapsing of a tube onto a rod and a stacking mechanism for stacking chalcogenide glass canes have all been established as part of fabrication route that has been d~veloped towards the realisation of a chalcogenide glass all-solid core microstructured optical fibre (MOF) comprising 37 core/clad canes based on the design parameters simulated. Furthermore, a robust method for obtaining for the first time multimode optical couplers based on core-clad chalcogenide glass fibre using the method of fibre sidepolishing has been demonstrated experimentally. A key feature is a novel and reproducible procedure developed for obtaining controlled side (D) polishing of chalcogenide glass fibre using an innovative polishing apparatus. These achievements are particularly noteworthy because chalcogenide glass fibre is "more toxic (requiring the use of fume extractors), requires inert atmosphere to prevent oxidation and complicated preparation methods, is difficult to handle and, due to the higher refractive indices, exhibits a higher degree of reflection at glass-air (~20%) interfaces than conventional silica glass fibre. Over the last few years, infrared rnicroscopy (IR) has gained interest and has been used to study cells and tissues for cancer diagnosis. The fabrication of IR-transmitting chalcogenide glass optical fibre tips has been investigated and tips exhibiting reproducible and controlled taper geometries have been demonstrated experimentally. f --- Additionally, methods for metal-coating the tips in a thermal evaporation chamber and cleaving the tips using a focused ion beam (FIB) have been successfully developed. Small diameter tips have been used as an IR probe in scanning near-field infrared microscopy (SNIM) and larger diameter tips for transflection spectroscopy in an attempt to obtain optical and topographical cell tissue data for cell IR fingerprint recognition of Chinese Hamster Ovary cells using synchrotron radiation by employing B22 Beamline of the Diamond Light Source, Oxford, UK. IR spectra was successfully collected and showed good indication of the amide I and amide II bands related with cell DNA.

The subject of the thesis is the modelling, design, fabrication and characterisation of passive silicon photonic devices for near (NIR) and mid-infrared (MIR) applications. The NIR devices have been investigated with the aim to produce low temperature sensitive devices for optical interconnects, whilst the results obtained at AIR wavelengths promise great potential for a variety of applications such as sensing and biomedicine. Silicon photonics offers very promising prospects for meeting ever-increasing demands on data speed and bandwidth. Temperature sensitivity of resonant photonic devices is an important issue in the development of ultralow power optical interconnects. This research project reports on the design, fabrication, and characterisation of a low temperature sensitive strip silicon-an-insulator (SOI) racetrack resonators. A resonant wavelength shift of 0.2 pm/K at a 1550 mm wavelength is measured using polymer cladding. The influence of various parameters has been examined achieving a very good agreement with theoretical model. A significant reduction of waveguide propagation losses, improved racetrack resonator Q-value, and higher extinction ratio are obtained after overlaying the silicon waveguides with a polymer cladding. On the other side, MIR silicon photonics is gathering pace, driven mainly by the lure of possible applications such as sensing, free-space communications, thermal imaging and biomedicine. However, the field is still in its infancy and the first serious challenge is to find suitable material platforms for the MIR. The thesis reports experimental results for passive devices based on different material platforms such as SOl, silicon-an-sapphire and silicon-an-porous silicon. It is demonstrated that SOl is useful material for integrated group IV photonics in the 3-4 f.1,m wavelength range, where propagation losses of less than 1 dB/cm have been obtained. The design rules for single-mode and zero-birefringent SOl rib waveguides using stress engineering are also presented. Optical splitters and racetrack resonators based on SOl strip waveguides have been characterised in the 3.7-3.9 11m wavelength range.

The detection of single photons is now commonplace in labs across the world. This was initially due to the invention of photomultiplier tubes (PMTs) and multichannel plates (MCPs) but the explosion in adoption was undoubtedly due to the developments in Single Photon Avalanche Photodiodes (SPADs), and most notably in silicon. The cost, bulk, weight, and complexity all dropped, and thus significantly expanded the application space. Today SPADs are found in biophotonics, sensing, rangefinding, quantum key distribution (QKD), quantum computing, and more This thesis investigates a relatively new class of single photon detectors, commonly referred to as shallow junction SPADs, and their applicability to a range of applications. These offer a further step reduction in cost and additionally allow for the creation of individually addressable arrays as well as integrated circuitry along side the detection areas.

Quantum information science provides new paradigms of communication, computation and measurement; such as perfectly secure quantum key distribution, intrinsic parallel computation and increased precision measurement by beating the standard quantum limit. The first implementation of optical quantum circuits whose performance exceeds that required for fault tolerance quantum computation is presented. Near- unit fidelity non-classical interference and entangling operations are demonstrated in integrated photonic waveguides fabricated on silica on silicon chips. Improvement of about 5% in the measured performance is the result of perfectly indistinguishable photon pairs produced from an SPDC source. These integrated devices, combined with high efficiency single photon sources and detectors, will be the building block for future demonstrations of quantum information. Operation of quantum optics circuits with superconducting nanowire single photon detectors (SNSPD) is reported. The lower jitter of SNSPDs compared to silicon single photon avalanche photodiodes (SPADs) enables the measurement of higher visibility non-classical interference on directional couplers, CNOT gates and Mach-Zehnder interferometer. SSPDs are fast, low noise and can detect single photons in a broad range of wavelengths. Recent studies show very high detection efficiency making these devices promising for future photonic quantum information processing. Quantum interference in multi-mode interference (MMI) devices is reported for the first time. These devices allow the design of NxM splitters with superior performances, excellent tolerance to polarization and wavelength variations and relaxed fabrication requirements compared to the other main beam splitting technology, the directional couplers. However, to date, there have been no demonstrations of quantum interference in MMI devices (one may be concerned that multi-mode operation could prevent or perturb such interference). It is found that that the quantum interference visibility is significantly lower than that of a directional coupler with the same source. A major reason for the reduced visibility is the coherence length of the photons, which is set by the large-band interference filters. Since the different modes see different effective refractive indices within the interferometer, a jitter is 'introduced which allows distinguishability between the photons. To overcome this problem a narrower filter was introduced in one of the channels between the device and the detector, i.e. not affecting the source. This quantum erasure technique increases the detected indistinguishability of the photons, showing a high visibility and confirming that timing jitter limits quantum interference with large filters. The first observation of quantum walks of two indistinguishable particles is reported. Quantum walks offer new tools for simulating physical, chemical and biological systems, performing universal quantum computation and studying generalized quantum interference. Experimental demonstrations to date have shown single particle quantum walks; the observable dynamics of which can be fully explained with classical wave mechanics and experimentally mimicked using, for example, bright laser light. To observe uniquely quantum mechanical correlations in quantum walks, the propagation of two single, indistinguishable photons in an array of 21 waveguides in a silicon oxynitride chip is measured. The simultaneous walk of two photons on a graph simulate the walk of a single photon on a larger graph; the graph growing exponentially when linearly increasing the number of photons. These results violate classical bounds and cannot be efficiently simulated or described using classical mechanics. It is shown that the output strongly depends on the input state. Previous quantum optical work has highlighted the promise of monolithic integrated optics for quantum information science. This demonstration takes advantage of the intrinsic stability of photonic waveguide circuits to perform two-photon interference on a large scale. The results presented in this Thesis demonstrate the potential of integrated quantum photonic technology for quantum information applications, in particular quantum computation and quantum simulation.

A key problem in nanotechnology is the integration of individual components into larger networks capable of more complex processes. DNA based photonic wires are a promising solution as they have been shown to transmit light energy over 10 nm distances, but are limited by their problematic assembly and reliance on fluorophore labelled DNA. This thesis describes efforts to construct an improved photonic wire using functionalised DNA binding small molecules as proof of principle for a ‘mix and match’ approach to nanotechnology which delivers individual components to a specific site on DNA. Polyamides have been shown to bind to DNA with very high affinity and specificity which together with their modular nature makes them an ideal ‘delivery system’. To combine this with the versatility and efficiency of copper catalysed click chemistry, novel internally functionalised alkyne polyamides were synthesised using both solution and solid phase chemistry. A general route to produce these internally modified polyamides was developed and the synthesis of the standard polyamide building blocks was improved. Test click reactions on alkyne polyamide fragments showed up to 92% conversion, but the same reactions failed on the full length polyamides and previously reported modification methods were used to create a fluorophore labelled polyamide. A coumarin based fluorophore was selected to allow direct substitution into proven photonic wires, but when the DNA binding affinity of this polyamide was tested, it was found that only weak binding was observed with 1.5 equivalents of polyamide. Upon construction, the improved photonic wire transported energy over a distance of 6 nm with an overall efficiency of 9% which was attributed to the poor DNA affinity. This poor performance makes it difficult to assess the general potential for this ‘mix and match’ approach, but the non-applicability of click chemistry and improvements in the synthesis will inform future designs.

The aim of this thesis is to consistently fabricate low OH content silica solid-core photonic crystal fibres of different core diameters, identified as low spectral attenuation at 1383 nm. Three different methods are proposed. Two of them are focused on preventing the OH contamination of glass during fabrication whilst the third method is focused on obtaining low OH fibres by reducing the OH content of already contaminated glass. The local attenuation at the ends of these low OH fibres is notoriously worsen when they are exposed to the atmospheric water vapour, the levels of this attenuation depending very strongly with core diameter. The low OH levels achieved (0.19 ppm) in the small-core photonic crystal fibres open the scope to applications in non linear optics where standard levels of absorption are detrimental. In particular, the principle of a widely tunable source (across the OH absorption peak at 1383 nm) delivering femtosecond pulses beyond 2 μm is demonstrated experimentally.

This PhD thesis investigates the optical properties of colloidal semiconductor nanocrystals and evaluates concepts regarding the development of novel photonic devices. Spectroscopic studies of the exciton dynamics in colloidal lead sulfide (PbS) quantum dots (QDs) by tuning the temperature are presented. The lowest exciton splitting for a range of PbS QDs sizes is calculated and a transfer of the oscillator strength from dark to bright states as the size increases is demonstrated. Hybrid structures with PbS QDs deposited on silicon substrates were also studied in order to explore whether excitons can be created in this material by means of resonant energy transfer. Furthermore, elongated asymmetric cadmium selenide/cadmium sulfide (CdSe/CdS) quantum rods are used as gain medium for the development of whispering gallery mode microlasers. Single-mode operation of hybrid lasers based on colloidal CdSe/CdS core/shell QRs in silica microspheres is for the first time reported. Laser-emission tunability over a range of 2.1 nm is also demonstrated, by heating the microsphere cavity with a 3.5-μm laser. In the last part of this thesis, unstructured and micro structured LiNbO3 are presented as excellent substrates for cell culture. Two commonly used neuron-like cells have been successfully proliferated and differentiated on both polar (±z) faces of LiNbO3 crystal substrates. Spatially selective attachment of neuron-like cells onto the domain engineered micro-structured substrates is also shown, providing the opportunity for the development of functional materials for the study of neuronal networks.

Photonic clystals are an exciting component in the field of nanophotonics. They allow the control, confinement and manipulation of light at the nanometre scale. The ability to fabricate photonic clystals with semiconductor fabrication technology makes them a suitable building block of photonic integrated circuits. Photonic clystals offer sensitivity to surrounding materials and they can enhance light-matter interaction. This has motivated considerable research into their application in the area of chemical and biological sensing. Photonic clystals provide a versatile platform for lab-on-a-chip applications and the prospect of high integration density could benefit cost-sensitive applications such point-of-care diagnostics or environmental sensing. This thesis investigates the feasibility of creating photonic crystal sensors on gallium nitride. The maturity of GaN-based photonic devices, such as LEDs, makes it an ideal platform for lab-on-a-chip applications. Two types of GaN photonic clystals sensors are designed, fabricated and characterised in this work. The first type is a ID grating, which supports guided mode resonances. These are fabricated by electronbeam lithography and dlY etching on GaN membranes and on GaN-on-sapphire. The ability of membrane gratings to sense the refractive index of a liquid that is present at one side of the membrane is verified experimentally. GaN-on-sapphire gratings are presented as a method of enhancing fluorescence emission from molecules placed on the gratings through the guided mode resonances. The second structure analysed is a modified 2D photonic clystal L3 cavity. This novel structure possesses a central hole, which allows the positioning of fluorescent molecules in a region of high electric field density. It is shown by finite difference time domain calculations, that the resonant modes of the cavity significantly enhance the absorption and emission of the molecules. The fabrication and characterisation of those cavities, along with coupling to ridge waveguides, are shown as a first step towards an integrated sensor.

The thesis presented here entitled “Structural and Optoelectronic Properties of Rare Earth Doped Silicon Photonic Materials” for the degree of Doctor of Philosophy is submitted to the University of Manchester by Hang Li in December 2012.The original work presented in this thesis concentrates on the origin of the luminescence and the possible radiative loss mechanisms in rare earth (RE) and silicon nanocrystals (Si-NCs) co-doped SiO2. The optoelectronic properties of these materials were studied by employing laser or Xe lamp correlated photoluminescence (PL) and time-resolved PL spectroscopy and the structural and compositional characterisation was carried out using transmission electron microscopy (TEM) and scanning TEM (STEM).The pressure dependence of the band-gap of Si-NCs is strongly correlated to the co-doped erbium (Er) concentration. A conventional diamond anvil cell (DAC) was used for applying the hydrostatic pressure. A strong quenching and a non-linear red-shift of the PL of Si-NCs were obtained with increasing pressure, which was attributed to the quantum confinement effect. The rate of the red-shift as a function of pressure (pressure coefficient) increases with increasing Er concentration. We propose that this is the result of a reduction in the surface tension of Si-NCs when Er ions gather at their surface.Er is present as the trivalent oxide (Er2O3) in silicon rich silicon oxide (SRSO). Large Er2O3 clusters are formed when silicon excess is low as silicon is considered as a competitor for oxygen. Under the indirect excitation, the PL of Er3+ at 1.54 μm is highly dependent on the sensitization by Si-NCs. The decay lifetime of this emission contains a slow component of about 10 ms and a fast component of the order of μs. We found that the fast component became considerably faster with increasing Er2O3 cluster size. This is an indication of strong Er3+ ion-ion interactions in large clusters, which give rise to the non-radiative recombination of excitons.A novel fabrication of RE doped SiO2 was developed by implanting RE ions into silicon wafer directly and followed by the thermal oxidation and rapid thermal annealing (RTA) in contrast to the conventional procedure, in which the ion implantation was carried out after the oxidation of silicon wafer. TEM images showed that RE ions were distributed close to the surface of SiO2 film via the novel method but via the conventional method they were located at certain depth below the surface. Ce3+ doped SiO2 prepared via both methods has a broad blue PL ranging from around 380 to 470 nm attributed to the 5d-4f transitions and Eu3+ has a red PL with several narrow bands in the range of 570 to 700 nm attributed to the intra-4f transitions. Concentration quenching is one of the limiting factors for the conventional fabrication whilst it is successfully minimised by the novel method. A new phase of Ce silicate (Ce2Si2O7) may grow after the high temperature RTA via the novel method and leads to a remarkable enhancement of the Ce3+ luminescence.

In this thesis I describe work that I have done in two separate research areas. The first involves optical micro manipulation of nano-scale objects and their orientation. The second concerns the development of a semiconductor laser to provide high beam quality,average and peak power and short pulse durations. Optical tweezers are an excellent tool to manipulate nano scale objects in all three dimensions. An additional degree of control, the rotational alignment of assymetrical particles, is demonstrated by polarisation analysis of two photon induced fluorescence of the trapped and rotated semiconductor nanorods.Mode-locked vertical external-cavity surface emitting lasers (VECSELs) have recently achieved multi-watt average power levels. Nevertheless the need to optimize the gain structure design, in order to consistently obtain sub 200 fs pulse durations, still remains. The evolution of the intra-cavity power build-up transient is utilized for a novel spectro-temporal technique which allows for the extraction of the curvature of the gain spectrum during actual operation and enables the observation of the evolution of the gain spectrum during lasing build-up. In addition a method to obtain the total cavity loss via the combination of the power build-up transient and photo luminescence decline, during lasing onset is shown. The use of an amplified, femtosecond-pulsed and GHz repetition rate VECSEL to generate multi-watt average power supercontinuum in photonic crystal fibres (PCFs) is presented. Supercontinuum generation with GHz pulse repetition rates is of interest for frequency combs as the high repetition rate increases the mode spacing of the comb and energy per mode. Two different PCFs, one with an all-normal dispersion profile and one with a zero dispersion wavelength (ZDW) at 1040 nm, are pumped with the amplified VECSEL pulses generating spectral components over 200 nm and 500 nm, respectively. The thesis concludes with a proposal to use the advantages of both optical tweezers and VECSELs to analyse and resonantly excite the vibrational frequencies of single nano-scale objects.

It has been of major interest in recent research to produce faster optical processing for many telecommunications applications, as well as other applications of high performance optoelectronics. The combination of one-dimensional photonic crystal structures (PhC) and narrow photonic wire (PhW) waveguides in high refractive-index contrast materials such as silicon-on-insulator (SOI) is one of the main contenders for provision of various compact devices on a single chip. This development is due to the ability of silicon technology to support monolithic integration of optical interconnects and form fully functional photonic devices incorporated into CMOS chips. The high index contrast of the combination of a silicon core with a surrounding cladding of silica and/or air provides strong optical confinement, leading to the realization of more compact structures and small device volumes. In order to obtain a wide range of device functionality, the reduction of propagation losses in narrow wires is equally important, although there are still performance limitations determined by fabrication processes. Compact single-row PhC structures embedded in PhW waveguide micro-cavities could become essential components for wavelength selective devices, especially for possible application in WDM systems. The high quality factor, Q, and confinement of light in a small volume, V, are important for optical signal processing and filtering purposes, implying large Purcell factor values. In this thesis, one-dimensional photonic crystal/photonic wire micro-cavities have been designed and modeled using both 2D and 3D versions of the finite-difference time-domain (FDTD) approach. These devices were fabricated using electron beam lithography (EBL) and reactive ion etching (RIE) for patterning of the silicon layer. The device structures were characterized with TE polarized light, using a tunable laser covering the range from 1480 nm to 1585 nm. Single-row periodic hole-type PhC mirrors consisting of identical and equally spaced holes were embedded in 500 nm wire waveguides. Two PhC hole mirrors were separated with a cavity spacer varying from 400 nm to 500 nm in length to form a micro-cavity. In contrast, several different cavity arrangements were also successfully investigated, - i.e. extended cavity and coupled micro-cavity structures. The experimental results on photonic crystal/photonic wire micro-cavity structures have demonstrated that further enhancement of the quality-factor (Q-factor) - up to approximately 149,000 at wavelengths in the fibre telecommunications range is possible. The Q factor values and the useful transmission levels achieved are due, in particular, to the combination of both tapering within and outside the micro-cavity, with carefully designed hole diameters and non-periodic hole placement within the tapered sections. On the other hand, a large resonance quality factor of approximately 18,500, together with high normalized transmission of 85% through the use of tapering on both sides of the hole-type PhC mirrors that formed the micro-cavity, has been obtained. For the extended cavity case, the multiple resonances excited within the stop band, together with substantial tuning capability of the resonances obtained by varying the cavity length has been demonstrated, together with a Q-factor value of approximately 74,000 at the selected resonance frequency with a normalised transmission of 40%. In addition, the coupled micro-cavity structures considered in this thesis have formed the basic building block for designing multiple cavity structures where the combination of several cavities splits the selected single cavity resonance frequency into a number of resonances that depends directly on the number of cavities used in the design. The coupling strength between the resonators and the Free Spectral Range (FSR) between the split resonance frequencies of the coupled cavity combination were controlled via the use of different numbers of periodic hole structures – and through the use of different aperiodic hole taper arrangements between the two cavities in the middle section of the mirrors.

Silicon based integrated circuits has been dominating the electronics technology industry in the last few decades. As the telecommunications and the computing industry slowly converges together, the need for a material to build photonics integrated circuits (PIC) that can be cost-effective and be produced in mass market has become very important. This thesis describes and outlines the characteristics of high index contrast waveguides as a building blocks that can be designed, fabricated and employed on devices in silicon photonics. Initially in this work, a fully vectorial H-field based finite element method has been used to obtain the modal characteristics of high index contrast bent waveguide to get a better understanding of the curved section. Through the beam propagation method, the propagation losses and the spot-size along the propagation distance are obtained when a mode from the straight guide is launched into a bent guide. It is also learnt that mode beating exists at the junction of a straight-to-bent waveguide, in which higher order modes will also be generated. It will be shown in this work that power do exchange between the two polarization states, therefore the polarization conversion, the power losses and the bending losses will be investigated. It will also shown in here that by applying lateral offsets with coupled waveguides of unequal widths, the insertion loss can be reduced. Secondly, for a high index contrast waveguide such as the silicon strip waveguide with a nanoscale cross-section, modes in such waveguide are not purely TE or TM but hybrid in nature, with all the six components of their E and H-fields being present. Therefore a detail analysis of the modal field profiles along with the Poynting vector profile will be shown. The effects of waveguide's width and height on the effective indices, the hybridness, the modal effective area and the power confinement in the core or cladding has been studied. Furthermore the modal birefringence of such strip waveguide will be shown. It will be presented that for a strip waveguide with height of 260 nm, single mode exists in the region of the width being 200 nm to 400 nm and that the modal effective is at its minimum when width is around 320 nm for both polarization states. Thirdly, a compact polarization rotator with an asymmetric waveguide structure design, suitable for fabrication that does not require a slanted side wall or curved waveguide is considered in this work. It will be shown in here that due to the hybrid nature of the asymmetric waveguide design, maximum polarization rotation (from TE to TM) will be achieve by enhancing the non-dominant field profile of both polarized fundamental mode. As the modal hybridness and the propagation constants of both polarized modes will be obtained, the half-beat length, polarization conversion and polarization cross-talk will be calculated by using the FEM and the least squares residual boundary method (LSBR). It is learnt that a compact single stage polarization rotator with a device length of 48 μm with more than 99% of polarization conversion is achieved in this work. Finally, a study of vertical and horizontal slot waveguide will be shown. Based on silicon strip waveguide, a detail modal characteristics of E and H-fields along with the Poynting vectors are presented. It will be shown that for slot waveguide, high power confinement and power density will be achieved in the slot area. It will be presented that by optimising the waveguide and slot dimension, the performance of the power confinement and power density in the slot region can be improved.

Rigorous numerical simulations have been carried out by using the Finite Element Method (FEM) in order to calculate bending and leakage losses of Photonic Crystal Fibres (PCF). A modal solution approach including the implementations of the conformal transformation and the Perfectly Matched Layer (PML) were undertaken to determine the bending and leakage losses of several designs of Photonic Crystal Fibres. This was carried out by varying key parameters such as the pitch (Λ), diameter (d) and air-filling fraction (d/Λ). Output modal parameters including the effective indices, spot sizes, leakage and bending losses as well as the mode field profiles were obtained. These output parameters were obtained by varying the bending radius (R) from very large values to very low values for different dimensions of the PCF, with results being obtained for Transverse Magnetic and Transverse Electric (quasi-TM and quasi-TE) polarizations. These parameters were calculated by solving the Maxwell’s equations using the H-field vector formulation and with the inclusion of PML to solve complex eigenvalue equations. Generally, it was observed that for all Λ, d/Λ and the polarization considered, as R is reduced from a very high value to lower values, the bending losses increase and there is a sharp increase at some lower values of R. At some very low values of R, some oscillatory behaviour was observed in the curves obtained for the fibre losses, where further investigations were carried out. These oscillations appeared due to degeneration of the fundamental mode with the cladding modes. In most of the cases investigated, there was a correlation in the variation of effective indices the loss values and also in the variation of spot sizes. PCFs with non-identical air-holes were also investigated in which case the d ≠ d2 (diameter of 4 larger air-holes in the first ring) and knowing the values for TM and TE polarizations, it was possible to determine the birefringence, which is the difference between the effective indices for the TM and TE modes and also the loss ratio, which is the ratio of TM loss to that of the TE loss. All the input and output parameters that were considered with the symmetric air-holes were also considered in the case with fibre with asymmetric air-holes study. The results obtained are very important in the design of Single Mode Single Polarization PCF. Results have also been obtained from the studies done of asymmetric arrangement of air-holes which lead to the design of Single Mode Single Polarization PCF. Work was carried out on the design of a tapered PCF that could be efficiently coupled to a single mode fibre, SMF. This was achieved by increasing the number rings up to 10 rings of air-holes in the cladding and having the outermost ring with larger air-holes, the inner rings were near cutoff. This fibre was coupled to a conventional SMF to allow for better tolerance to fabrication errors. There has also been work carried out in polymer fibre namely Teflon and TOPAS in the terahertz regime. The conventional hexagonal arrangement of PCF was simulated and compared to spiral PCF in THz. An improved PCF design having a porous core with hexagonal arrangement and cladding was designed and analysed and low-loss guidance in THz was achieved. Thus overall a number of different PCF designs were considered and their properties evaluated and detailed knowledge has been obtained on potential performance of such fibres.

This thesis presents studies of novel terahertz photonic devices, including photoconductive optoelectronic devices and guided-wave components, aimed at the development of next-generation terahertz systems. In chapter 2, a scalable interdigitated THz transmitter is designed to increase the output power and compared with a conventional 50 μm coplanar transmitter. In chapter 3, we compare four different receivers with different antenna geometries in terms of bandwidth and sensitivity. Then we describe a photoconductive near-field detector with a subwavelength aperture and its system integration and characterization. In chapter 4, a parallel metal plate waveguide is designed with an integrated step inside the waveguide that can couple to higher order TM modes efficiently from the TEM mode. In this chapter, we also experimentally and numerically study a 2-dimensionally tapered parallel plate waveguide, by which a free-space THz beam can be focused into a deep subwavelength-scale volume. In chapter 5, a parallel thin dielectric film waveguide is used to explore the guiding mechanism of an antiresonant optical reflection waveguide. Cylindrical silica single capillaries and a microstructured capillary, which guide in a similar way, are characterized in terms of mode profiles and attenuation. In chapter 6, we study oblique transmission through freestanding thin nickel films, which are perforated with periodic conical hole arrays. Surface modes can be supported by both metallic surfaces with different nonlinear dispersion curves, which results in spectral interferences in a near-field region when the surface modes couple out of the waveguide into free space.

Photons have proven to be an effective test-bed for the fundamental concepts and elements of quantum-enhanced technologies. As systems become increasingly complex, however, practical considerations make the traditional approach of bulk optics and free-space propagation progressively more difficult. The major obstacles are the physical space necessary to realise and operate such a complex system, its stability, and maintaining low losses. In order to address these issues, quantum optical technologies can take a cue from their classical counterparts and look towards an integrated architecture to provide miniaturisation, greatly enhanced stability, less alignment, and low loss interfaces between different system components. In this thesis the feasibility of chip-based waveguides as a platform for metrology and information processing will be explored. In Part I, the necessary criteria for a metrology system to out-perform its classical counterpart will be investigated. It will be found that loss is a major barrier to this aim and, critically, that it is unlikely to have been achieved to date by any experiment which consumes resources of a fixed photon number. The issue of loss will be addressed by developing a scalable heralded source of a class of entangled photonic states which are both robust to losses and practically feasible to prepare. A novel tomographic technique will be developed to characterize these states and it will be explicitly demonstrated how it is possible to beat some bounds on classical performance without being able to out-perform a comparable classical system. Finally, a proof of principle demonstration of a waveguide-based interferometer with an integrated phase-shifter will be undertaken. It will be shown that the device preserves quantum interference, making it suitable for use in quantum-enhanced metrology applications. In Part II, integrated optics in the context of information processing will be discussed. First, a novel characterization technique will be developed which enables the behaviour of complex circuits to be predicted. The technique is independent of loss in the device being characterized. A method of simulating these circuits will be outlined that takes advantage of the computational speed-up available from parallelisation and sparse matrix operations. A key increase in complexity for integrated photonic systems will be demonstrated by showing quantum interference of three photons from two separate sources in eight spatial modes. The resulting interference has a visibility which beats all possible classical interference visibilities for similar circuits. Finally, a fully integrated waveguide-coupled photon-number-resolving detector will be developed and demonstrated. This proof of concept demonstration will show good resolution of different photon number events. The device will be modelled and routes to high efficiency operation will be explored.

Les polaritons de cavité sont des particules mixtes lumière-matière résultant du couplage fort entre excitons de puits quantiques et photons de cavité dans des microcavités semi-conductrices. Ils s'avèrent être une plate-forme extraordinaire pour émuler des Hamiltoniens 1D et 2D. Cela est dû au contrôle de site unique lors de la fabrication de réseaux de polaritons, ainsi qu'à la possibilité de visualiser directement la dispersion, les fonctions propres résolus en espace et la propagation des polaritons via des expériences de photoluminescence. En gravant une microcavité à base de GaAs, un réseau en nid d'abeille pour polaritons a été fabriqué. Les deux bandes d’énergie les plus basses de cette structure émulent pour les photons les bandes π et π * du graphène. Remarquablement, le système permet également d'explorer des degrés de liberté orbitaux, inaccessibles dans le graphène réel. Dans la première partie de cette thèse, cet émulateur à polaritons est utilisé pour aborder la physique des états de bord dans un réseau en nid d'abeille. De nouveaux états de bord, à caractère plat et dispersif, ont été découverts et visualisés dans le graphène orbital. Dans la deuxième partie de la thèse, nous démontrons expérimentalement une méthode pour adapter la dispersion de Dirac pour les photons. En mettant en œuvre une déformation uniaxiale dans le réseau en nid d'abeille, des photons de Dirac qui combinent des masses effectives nulle, finie et infinie sont créés. Les résultats présentés ouvrent de nouvelles perspectives pour l'ingénierie d’interfaces entre différents types de dispersions de Dirac. De plus, la partie excitonique des polaritons assure une sensibilité au champ magnétique, créant la possibilité de briser la symétrie d'inversion temporelle du système et d'étudier les états de bord topologiques photoniques dans des cônes de Dirac exotiques
Exciton polaritons are mixed light-matter particles arising from strong coupling of quantum well excitons and cavity photons in semiconductor microcavities. They prove to be an extraordinary platform to emulate 1D and 2D Hamiltonians. This is due to the single site control when fabricating polariton lattices as well as to the possibility to directly visualize dispersion, spatial eigenfunctions and propagation of polaritons in photoluminescence experiments. By etching GaAs-based microcavity a honeycomb lattice for polaritons has been fabricated. The lowest two bands of this structure emulate for photons the π and π* bands of graphene. Remarkably, the system also permits exploring orbital degrees of freedom, inaccessible in actual graphene. In the first part of this thesis polariton emulator is used to address the physics of edge states in honeycomb lattice. New edge states, with flat and dispersive character have been discovered and visualised in orbital graphene. In the second part of the thesis we demonstrate experimentally a method to tailor the Dirac dispersion for photons. By implementing uni-axial strain in the honeycomb lattice Dirac photons that combine zero, finite and infinite effective masses are created. Presented results open new perspectives for the engineering of interfaces between various types of Dirac dispersions. Furthermore, the excitonic part of polaritons assures sensitivity to the magnetic field, creating the possibility to break the time reversal symmetry of the system and study photonic topological edge states in exotic Dirac cones. Finally, nonlinear Dirac physics can be probed in this system owing to polariton-polariton interactions

Нaвeдeнo cхeму пiдключeння aвтoнoмнoї кoтeльнi дo icнуючoї тpaнcфopмaтopнoї пiдcтaнцiї. Пpeдcтaвлeнo пpинципoву cхeму кoнвeктивнoгo вoдoгpiйнoгo кoтлa йoгo пapaмeтpи тa тeхнiчну хapaктepиcтику. Нaвeдeнo cхeму кepувaння пpoeктoвaнoї cиcтeми тeплoпocтaчaння нaвчaльнoгo кopпуcу. Зaпpoпoнoвaнo зaхoди пo змeншeнню тeплoвих втpaт чepeз oгopoджуючi кoнcтpукцiї. Poзpaхoвaнo тeплoтeхнiчнi пoкaзники нaвчaльнoгo кopпуcу № 5 ТНТУ iм.I.Пулюя. Визнaчeнo питoмi тeплoвi втpaти нa oпaлeння.
Метою роботи є розробка системи електротеплоакумуляційного електрообігріву навчального корпусу для забезпечення споживачів теплом та гарячою водою. Основним технічним рішенням роботи є впровадження енергоефективного облад-нання, а також технологічні особливості роботи системи електротеплоакумуляційного обігріву навчального корпусу, яка буде працювати за диференційованими тарифами на електроенергію. Аналіз актуальності проблемної ситуації, полягає у вирішенні питання, що може суттєво розширити масштаби розповсюдження електрообігріву в Україні. Одним з перспективних шляхів підвищення енергоефективності електрообігріву є перехід до електротеплоакумуляційних технологій. Тобто, заміна традиційних котелень на електроопалювальні акумуляційні комплекси з переведенням їх у режим споживання електроенергії тільки вночі з багатотарифним обліком електроенергії є одним з найдоцільніших засобів підвищення енергоефективності.
The aim of the work is to develop a system of electro-heat-accumulating electric heating of the educational building to provide consumers with heat and hot water. The main technical solution is the introduction of energy-efficient equipment, as well as technological features of the electric heating system of the educational building, which will operate at differentiated tariffs for electricity. Analysis of the urgency of the problem situation is to address the issue, which can significantly expand the distribution of electric heating in Ukraine. One of the promising ways to increase the energy efficiency of electric heating is the transition to electro-heat storage technologies. That is, the replacement of traditional boilers with electric heating storage complexes with their transfer to the mode of electricity consumption only at night with multi-tariff metering of electricity is one of the most appropriate means of improving energy efficiency.
ПEPEЛIК УМOВНИХ CКOPOЧEНЬ 6 ВCТУП 7 1 AНAЛIТИЧНИЙ POЗДIЛ 9 1.1 Oцiнкa мoжливocтeй впpoвaджeння eлeктpoтeплoaкумуляцiйних тeхнoлoгiй в Укpaїнi 9 1.2 Пpoблeми eлeктpoaкумуляцiйнoгo oбiгpiву 17 1.3 Пocтaнoвкa зaдaчi дo пpoeктувaння 20 2 ПPOEКТНO-КOНCТPУКТOPCЬКИЙ POЗДIЛ 21 2.1 Тeплoтeхнiчнa чacтинa 21 2.2 Eлeктpoтeхнiчнa чacтинa 28 2.3 Виcнoвки дo poздiлу 2 35 3 POЗPAХУНКOВO-ДOCЛIДНИЦЬКИЙ POЗДIЛ 36 3.1 Poзpaхунoк тeплoтeхнiчних пoкaзникiв нaвчaльнoгo кopпуcу №5 36 3.2 Poзpaхунoк тeплoвих втpaт, тa тeплoвoї пoтужнocтi пpoeктoвaнoї кoтeльнi 43 3.3 Тeхнiкo-eкoнoмiчнi poзpaхунки зaпpoвaджeння cиcтeми oпaлeння нaвчaль нoгo кopпуcу №5 50 3.4 Виcнoвки дo poздiлу 3 53 4 БEЗПEКA ЖИТТЄДIЯЛЬНOCТI ТA OCНOВИ OХOPOНИ ПPAЦI 54 4.1 Пpaвилa бeзпeки пpи eкcплуaтaцiї eлeктpoтeплoaкумуляцiйних cиcтeм 54 4.2 Poзpaхунoк зaхиcнoгo зaнулeння cиcтeми eлeктpoтeплoaкумуляцiйнoгo oбiгpiву 55 4.3 Бeзпeкa пpи гaciннi eлeктpoуcтaнoвoк 59 ЗAГAЛЬНI ВИCНOВКИ 61 ПEPEЛIК ПOCИЛAНЬ 63

La technique Lidar Radar est couramment utilisée pour la détection de cibles immergées dans des eaux peu profondes inférieures à quelques dizaines de mètres. Cette technique repose sur l’envoi d’un signal modulé associé, à la réception avec un filtre passe bande autour de la fréquence de modulation. Cette technique requiert ainsi un signal optique bleu vert, intense, modulé à des fréquences radar. Nous présentons dans cette thèse de nouvelles architectures de modulateur parfaitement adaptées à cette technique. La 1ère architecture est constituée d’une cavité externe comportant un doubleur intracavité. Cette architecture est couplée à une source laser picoseconde infrarouge (1064 nm). Les résultats ont montré que ce modulateur permet de générer un signal vert (532 nm), intense (5 mJ) et stable en fréquence. Grâce à la source utilisée, le signal modulé en sortie de l’émetteur (source laser et modulateur) ne dure que quelques nanosecondes. Ceci permet d’utiliser la méthode de « range-gating » pour obtenir une précision sur la localisation de la cible. Néanmoins, ce dispositif présente l’inconvénient d’avoir une bande passante du signal émis fixe. Nous avons donc développé une deuxième architecture du modulateur, permettant d’accorder facilement la bande passante du signal émis. Cette configuration repose sur le comportement polarimétrique des composants optiques afin de changer la largeur de bande passante du signal. Nous avons montré que ce modulateur permet de délivrer, un signal intense (jusqu’à 2,9 mJ), court (quelques nanosecondes), à 532 nm, modulé à des fréquences radar, stable en fréquence et accordable en bande passante
The Lidar Radar technique is commonly used for submerged target detection in shallow waters less than a few tens of meters. This technique is based on sending a modulated signal, associated with a bandpass filter around the modulation frequency after detection. This technique requires an intense blue-green optical signal modulated at radar frequencies. We present in this thesis new modulator architectures perfectly adapted to this technique. The first architecture consists of an external cavity with an intracavity SHG stage. This architecture is coupled to an infrared picosecond laser source (1064 nm). The results showed that this modulator makes it possible to generate a green signal (532 nm), intense (5 mJ) and stable in frequency. Thanks to the source used, the signal modulated at the output of the transmitter (laser source and modulator) lasts only a few nanoseconds. This makes it possible to use the "range-gating" method to precisely locate the target.Nevertheless, this device has the disadvantage of a fixed bandwidth. We have therefore developed a second architecture of the modulator, allowing to easily tune the bandwidth of the transmitted signal. This configuration is based on the polarimetric behavior of the optical components in order to change the bandwidth of the signal. We have shown that this modulator can deliver , an intense signal (up to 2.9 mJ), short (a few nanoseconds), at 532 nm, modulated at mirowave frequencies, stable in frequency and tunable in bandwidth

Au cours des dix dernières années, les nanostructures photoniques ont représenté un paradigme pour le contrôle des radiations thermiques, offrant un panel de propriétés passionnantes pour les applications énergétiques. En raison de leurs capacités à contrôler et à gérer les ondes électromagnétiques à l'échelle de la longueur d'onde dans l’infrarouge moyen (Mid-IR), les nanostructures photoniques ont démontré leur capacité à gérer les propriétés des radiations thermiques d'une manière radicalement différente des émetteurs thermiques conventionnels. Les progrès fondamentaux du contrôle du rayonnement thermique ont conduit à différentes applications dans le domaine de l'énergie, comme les dispositifs thermophotovoltaïques ou à travers le concept de refroidissement radiatif diurne pour diminuer passivement la température des installations terrestres. Récemment, un autre domaine d'application est apparu dans le contrôle du rayonnement thermique, avec l'introduction de nanostructures photoniques dans les textiles. Le but de la thèse est d’étudier différentes membranes photoniques passives qui modulent le rayonnement optique du corps humain dans l’IR moyen pour assurer la thermorégulation individuelle. Pour cela, nous avons étudié les propriétés optiques de membranes polymères, en fonction de leur structuration. Nous avons montré que la membrane photonique est capable de moduler l'amplitude de transmission de 28% au profit ou au dépend de l'absorption et de la réflexion. Nous avons déterminé le bilan thermique entre le corps humain et le milieu environnant à travers la membrane photonique, en tenant compte des mécanismes de rayonnement, de convection et de conduction. Nous avons trouvé que la température de la peau est supérieure de presque 2 °C lorsque le corps humain est revêtu d'une membrane photonique structurée. Cette étude a été réalisée à partir de calculs analytiques et de codes de simulation numérique par la méthode des éléments finis (FEM). L’étude numérique a été accompagnée par des expériences de fabrication en salle blanche à l’IEMN et de caractérisation par spectroscopie infra rouge (FTIR) à l’école d’ingénieur HEI
For the past ten years, photonic nanostructures have represented a paradigm for the control of thermal radiations, offering a panel of exciting properties for energy applications. Because of their abilities to control and manage electromagnetic waves at the Mid-Infrared (Mid-IR) wavelength scale, photonic nanostructures demonstrate their ability to manage thermal radiations properties in a way drastically different from conventional thermal emitters. The fundamental advances in controlling thermal radiation led to different applications in the energy domain, as thermo photovoltaic devices or through the concept of daytime radiative cooling to passively decrease the temperature of terrestrial structures. Recently, another field of application has appeared in the thermal radiation control, with the introduction of photonic nanostructures in textiles for personal thermoregulation. The goal of the thesis is to study different passive photonic membranes that modulate the human body optical radiations in the Mid-IR for personal thermoregulation. We have investigated the optical properties of different polymer membranes, considering the effect of their structuration. We showed that a photonic crystal membrane is able to modulate the transmission coefficient by 28% in benefit or deficit of both the absorption and reflection. We analyzed the thermal balance between the human body and the indoor environment through the photonic membrane, considering the radiation, convection and conduction mechanisms. We found that the temperature of the skin is almost 2°C higher when the human body is clothed with a structured membrane. The study was carried out on analytical calculations and numerical simulation with the help of the finite element method (FEM). The numerical study was supported by experiments in fabrication in the IEMN cleaning room and in characterization by infrared spectroscopy (FTIR) at the HEI engineering school

Les nano-antennes sont des composants nanostructurés capables de concentrer la lumière dans des volumes sub-longueur d’onde, exaltant le champ électrique selon plusieurs ordres de grandeur. Cela est particulièrement intéressant pour la génération d’effets non linéaires, qui dépendent des puissances du champ électrique incident. En effet, les effets non linéaires d’ordre 2, qui permettent les phénomènes de conversion de fréquence, comme la génération de second harmonique (SHG), ou la différence de fréquence (DFG), dépendent du carré du champ électrique. Ainsi, si l’on inclut un cristal non linéaire dans une nano-antenne, on peut exalter significativement ces effets. L’objectif de cette thèse est donc de concevoir des nano-antennes permettant de générer efficacement des effets non linéaires d’ordre 2. De tels dispositifs pourraient être appliqués à la création de nouvelles sources pour la spectroscopie infrarouge.Le travail de thèse va de la modélisation électromagnétique des effets non linéaires dans les nanostructures à la démonstration expérimentale. La modélisation de polarisation non linéaire générée suivant l’axe optique a été développée en s’appuyant sur une méthode modale B-Spline pour les calculs linéaires. Ce modèle a permis de simuler les effets non linéaires liés à cette polarisation, d’affiner la compréhension des phénomènes physiques dans les nanostructures multi-résonantes, et d’optimiser une structure ayant une efficacité de 0.1 W/W² en différence de fréquence dans l’infrarouge. La conception d’un échantillon a permis de valider les propriétés résonantes, ainsi qu’une démonstration expérimentale de génération de second harmonique
Nano-antennas are nanostructured componentscapable of concentrating light in subwavelengthvolumes, exalting the electric field by severalorders of magnitude. This is particularly interestingfor the generation of nonlinear effects, which dependon the powers of the incident electric field. Actually,the second order non-linear effects, which allowfrequency conversion phenomena, such as secondharmonic generation (SHG), or difference frequencygeneration (DFG), depend on the square of the electricfield. Thus, if we include a nonlinear crystal in anano-antenna, we can significantly enhance these effects.The objective of this thesis is thus to designnano-antennas that can efficiently generate secondorder nonlinear effects. Such devices could be appliedto the creation of new sources for infrared spectroscopy.The thesis work ranges from electromagnetic modellingof nonlinear effects in nanostructures to experimentaldemonstration. The modelling of nonlinear polarizationgenerated along the optical axis has beendeveloped using a B-Spline modal method for linearcalculations. This model has allowed to simulate thenonlinear effects related to this polarization, to refinethe understanding of physical phenomena in multiresonantnanostructures, and to optimize a structurewith an efficiency of 0.1W/W² in difference frequencygeneration in the infrared. The design of a sample allowedthe validation of the resonant properties, as wellas an experimental demonstration of second harmonicgeneration

À travers l’histoire, la lumière a suscité le plus vif intérêt chez de nombreuses personnes curieuses, qu’il s’agisse de philosophes questionnant sa nature ou de scientifiques cherchant à interpréter les phénomènes qui lui sont associés. L’optique joue un rôle essentiel dans nombre de nos applications quotidiennes. L’indice de réfraction est l’un des facteurs les plus importants en photonique. Il est possible d’améliorer l’efficacité des dispositifs photoniques, comme les diodes électroluminescentes, les cellules photovoltaïques, etc., en réduisant la disparité des indices de réfraction des matériaux utilisés dans les dispositifs optiques. Cette thèse apporte quelques éclaircissements sur l’adaptation de l’indice de réfraction des matériaux, détaillant des aspects de l’indice de réfraction et de son ingénierie à l’aide de nanocomposites de polymère. Ce chapitre d’introduction évolue vers une discussion plus large sur l’indice de réfraction, ses différentes valeurs, et les avantages potentiels que son ingénierie pourrait générer. De minces films polymères ont été préparés et les nanoparticules ont été introduites de façon à modifier l’indice de réfraction. De la même manière, des films épais ont été préparés en utilisant du PMMA et du polystyrène, ceux-ci ayant été utilisés pour caractériser optiquement et morphologiquement les échantillons préparés. De nombreuses méthodes ont été employées pour préparer les films polymères. Des films polymères ultraminces ont également été préparés en utilisant la technique de revêtement par centrifugation, puis l’épaisseur du film de polystyrène a été modifiée afin d’étudier son impact sur l’indice de réfraction. Il a fallu surmonter plusieurs obstacles lors des recherches, comme la préparation d’un substrat ultra pur, l’uniformité du film polymère mince préparé, l’adhérence du film polymère mince sur les substrats après le coulage au solvant, etc. Tous ces défis ont été relevés grâce aux innovations détaillées dans cette thèse
Historically, light was a centre of interest for numerous inquisitive people: the philosophers who were interested in its nature and the scientists who wanted to interpret its associated phenomena. Optics is playing a pivotal role in many of our day to day applications.The refractive index is one of the most significant parameters in photonics. An increase in the efficiency of the photonic devices, like Light Emitting Diodes, Solar Cells, etc., can be achieved by reducing the refractive index mismatch of materials used in the optical devices.This thesis throws some light into the tailoring the refractive index of materials, by giving detailed aspects of refractive index and engineering of the refractive index using polymer nanocomposite. This introductory chapter evolves into a wider discussion on the refractive index and the types of refractive index and the potential leverage that can be obtained by engineering the refractive index. Polymer thin films were prepared and the nanoparticles were introduced so as to modify the refractive index. Similarly, thick polymer films were prepared using PMMA and Polystyrene and these were utilized to optically and morphologically characterize the prepared samples. Multiple methods have been utilized to prepare the polymer films. Ultra thin polymer films were also prepared using the spin coating technique and later the thickness of the polystyrene film was changed so as to understand its impact on the refractive index. There were multiple challenges to overcome while carrying out the research like the preparation of ultra pure substrate, uniformity in the prepared polymer thin film, adherence of the polymer thin film on to the substrates after solvent casting etc. All the challenges were overcome using the innovations, which are detailed in the thesis

La Tomographie Optique Diffuse (TOD) est une nouvelle technique d'imagerie médicale permettant de reconstruire les propriétés optiques des tissus biologiques dans le but de détecter des tumeurs cancéreuses. Il s’agit, toutefois, d’un problème inverse mal-posé et sous-déterminé. Le travail de cette thèse s’articule autour de la résolution de ce problème en utilisant l’équation du transfert radiatif comme modèle de propagation de la lumière (modèle direct). L’analyse de sensibilité a montré que le facteur d’anisotropie g de la fonction de phase de Henyey-Greenstein est le paramètre le plus influant sur la sortie du modèle direct suivi du coefficient de diffusion µs puis du coefficient d’absorption µa. Dans un premier temps, un algorithme de Gauss-Newton a été implémenté en utilisant les fonctions de sensibilités. Toutefois, ce dernier ne permet d’estimer qu'un nombre très limité de paramètres optiques (supposés constants en espace). Dans un second temps, un algorithme de Quasi-Newton a été développé pour reconstruire les distributions spatiales des propriétés optiques. Le gradient de la fonction objectif a été calculé efficacement par la méthode adjointe à travers le formalisme de Lagrange avec une approche Multi-fréquences. Les reconstructions sont obtenues à partir des données simulées en surface. Le facteur g est reconstruit comme un nouvel agent de contraste en TOD. Le problème de diaphonie entre µs g a été donc mis en évidence dans cette thèse. Notre algorithme a permis de reconstruire en 2D et 3D une ou plusieurs inclusions tumorales présentant différentes formes. La qualité des images reconstruites a été examinée en fonction du nombre de fréquences, de la diaphonie, du niveau de contraste (Inclusion/Fond), du niveau de bruit et de la position des inclusions tumorales
Diffuse Optical Tomography (DOT) is a new medical imaging technique used to reconstruct the optical properties of biological tissues in order to detect cancerous tumors. However, this is an ill-posed and under-determined inverse problem. The work of this thesis deals with the resolution of this problem using the radiative transfer equation as a forward model of light propagation. The sensitivity analysis showed that the anisotropy factor g of the Henyey-Greenstein phase function is the most sensitive parameter of the forward model followed by the scattering coefficient µs and then the absorption coefficient µa. In a first step, a Gauss-Newton algorithm was implemented using the sensitivity functions. However, this algorithm allows to estimate a very limited number of the optical parameters (assumed to be constant in space). In a second step, a Quasi-Newton algorithm was developed to reconstruct the spatial distributions of the optical properties. The gradient of the objective function was efficiently computed by the adjoint method through the Lagrangian formalism with a Multi-frequency approach. The reconstructed images were obtained from simulated boundary data. The g factor was reconstructed as a new optical contrast agent in DOT and the crosstalk problem between this factor and µs has been studied. The results showed that the algorithm is efficient to reconstruct in 2D and 3D one or several tumor inclusions having different shapes. The quality of the reconstructed images was examined according to several parameters: the number of frequencies, the crosstalk, the contrast and the noise levels

Les énergies renouvelables peuvent à la fois répondre au besoin croissant en énergie tout en répondant à la nécessité de décarboniser l’énergie. La ressource énergétique solaire est quasi infinie (la terre reçoit plus d’énergie solaire en une heure qu’elle en consomme en un an) mais reste pourtant peu exploitée. Les cellules solaires hybrides à base de perovskite connaissent depuis les années 2000 un essor sans précédent dans le monde de la recherche en technologies solaires. Elles appartiennent à la catégorie des films minces, et nécessitent donc bien moins de matière première que les cellules au silicium, pour le moment largement majoritaires sur le marché. Cependant, elles n’absorbent pas au-delà de 800 nm, et tout l’infra-rouge est donc non converti par ce type de cellules solaires. Ce doctorat a pour but d’augmenter l’absorption dans l’infrarouge et donc le rendement de la cellule solaire. Pour cela, on y place des particules appelées nanoparticules d’upconversion, qui convertissent un rayonnement infrarouge en visible. Il s’agit d’un phénomène d’absorption simultané de deux photons. Cet effet ayant un rendement assez faible, il convient de le booster par l’insertion de nanoparticules métalliques afin de pouvoir bénéficier de l’augmentation de l’intensité du champ électromagnétique dans leur voisinage proche (effet dit plasmonique). En combinant les deux types de particules on parvient à augmenter l’absorption des particules à upconversion, et en les plaçant tous deux dans une cellule solaire, on augmente donc son rendement
Renewable energies represent nowadays one of the keys that can tackle at the same time energy supply needs and a sustainable environmental behavior. Photovoltaic devices convert the energy of sunlight into electricity, and solar energy remains one of the most common renewable energy sources. In the search for cost-effective solar cells, the recently discovered solution-processable hybrid organic-inorganic perovskites are considered as one of the most important candidates. They belong to the category of thin-film technologies and require much less and as abundant resource than Si. One limiting parameter of such photovoltaic devices is however the absorption of low-energy photons (wavelength over 800 nm, the near-infrared range). In order to address this specific loss of sub bandgap photons’ absorption, this PhD thesis aims to develop plasmonic-enhanced upconversion approaches to extend the spectral sensitivity of organo-metal halide perovskite solar cells to the near-IR spectrum. Near-infrared-to-visible up-conversion fluorescent materials can be used to widen the part of the spectrum used for electric current generation. Two low-energy photons are added up in order to give a higher energy photon. However, this effect has a rather small efficiency. This effect being quite inefficient, the idea is to combine those particles with metallic nanoparticles, that have the property to enhance electromagnetic field intensity at a certain wavelength (this is called plasmonic effect). By combining both types of particles, we thus enhance the activity of up-conversion materials (higher emission). Once implemented in a perovskite solar cell, this increases its efficiency

Дисертація спрямована на вирішення важливої науково-технічної проблеми розвитку науково-технологічних основ високотемпературних (600 –3000 °С) хімічних процесів у електротермічному псевдозрідженому шарі (ЕТПШ) з одержанням чистого графіту, високотемпературного воденьвмісного газу, піровуглецевого покриття, пірографіту та чистого карбіду кремнію. Поставлені задачі вирішені шляхом теоретичних та експериментальних методів вивчення високотемпературних процесів у ЕТПШ. Для аналізу ефективності теплових процесів і режимів роботи використовуються термодинамічні методи, методи теорії тепло- та масообміну, методи теорії подібності. Серед вагомих наукових результатів можна виділити: теоретично та експериментально доведена можливість високотемпературного очищення природного графіту Заваліївського родовища у ЕТПШ; на основі термодинамічних розрахунків визначені основні теплотехнічні характеристики високотемпературних процесів, які доцільно проводити у ЕТПШ; на основі термодинамічних та теплотехнічних розрахунків встановлені основні параметри, необхідні для створення та конструювання нового обладнання з ЕТПШ; створено парк експериментального обладнання з ЕТПШ з різними характеристиками та способом нагрівання для дослідження високотемпературних термохімічних процесів; на основі експериментальних даних та з застосуванням сучасного мікроскопічного обладнання визначена залежність між структурою піровуглецю та теплотехнічними параметрами процесу піролізу вуглеводневих газів; розроблено методику визначення густини піровуглецевого покриття на дисперсному матеріалі; проведенням серії експериментів на різних установках з ЕТПШ визначено оптимальну температуру (1500 °С) та конструкцію реактору з ЕТПШ для виходу 98 % об. водню під час реакції піролізу метану; удосконалено конструкцію реактора з ЕТПШ для обробки діелектричного матеріалу шляхом застосування комбінованого способу нагрівання; вперше експериментально досягнута температура ЕТПШ 3070 °С; вперше експериментально доведено утворення карбіду кремнію з капсульованого піровуглецем кварцового піску при високотемпературній обробці у реакторі з ЕТПШ; експериментально доведена принципова можливість нанесення піровуглецевого покриття у ЕТПШ на моделі мікротвелу, які за своїми фізико-хімічними властивостями наближені до дисперсного ядерного палива (Dy2O3, Gd2O3, Sm2O3); удосконалено методику розрахунку теплового балансу для проведення термохімічних процесів у типовому реакторі з ЕТПШ, під час проведення експериментальних досліджень підтверджено адекватність даної методики; при випробуваннях дослідних зразків пресованих прокладок з терморозширеного графіту (в основу якого закладений графіт очищений у ЕТПШ) було визначено, що їх механічна міцність відповідає показникам раніш використовуваних прокладок фірми «Гідропресс» (РФ). Результати досліджень відкривають перспективи для створення енергоефективної та екологічно чистої технології очищення природного та штучного графіту; можуть бути використані при створенні виробництва водню як для хімічної промисловості, так і для металургії (високотемпературний водневмісний газ); відкривають перспективу створення енергоефективної технології одержання високочистого дрібнодисперсного карбіду кремнію. Одержані експериментальні дані щодо залежності структури піровуглецевого покриття від теплофізичних параметрів процесу та проведені дослідження його матеріалознавчих характеристик, які відкривають широку перспективу застосування одержаних піровуглецевих покриттів у хімічній технлології, енергетиці та різних високотехнологічних галузях. Одержані результати з нанесення піровуглецевого покриття на дисперсні матеріали з високою густиною мають перспективу застосування у спецметалургії. Результати досліджень з виготовлення ущільнюючих прокладок з ТРГ передані ВП «Атоменергомаш» ДП НАЕК «Енергоатом» для створення виробничої дільниці. Повне освоєння всього циклу виробництва ущільнень з ТРГ дозволить ліквідувати імпортозалежність країни в цій сфері та підвищити безпеку експлуатації вітчизняних АЕС. The dissertation is aimed at solving an important scientific and technical problem of development of scientific and technological bases of high – temperature (600… 3000 ° C) chemical processes in an electrothermal fluidized bed (ETFB). These processes include the production of pure graphite, a high-temperature hydrogencontaining gas, pyrocarbon coating, pyrographite, and pure silicon carbide. These problems are solved by theoretical and experimental methods of studying high-temperature processes in the ETFB. To analyze the efficiency of thermal processes and modes of operation, thermodynamic methods, methods of heat and mass transfer theory, methods of similarity theory are used. The important scientific results are: on the basis of thermodynamic calculations the basic thermotechnical characteristics of high-temperature processes which it is expedient to carry out in the ETFB are defined; on the basis of thermodynamic and thermotechnical calculations the basic parameters necessary for creation and design of the new equipment from ETFB are established; the possibility of high-temperature purification of natural graphite of the «Zavaliyevskoye deposit» in the ETFB is theoretically and experimentally proven; a park of experimental equipment with ETFB with different characteristics and method of heating for the study of high-temperature thermochemical processes is created; on the basis of experimental data and with the use of modern microscopic equipment the dependence between the structure of pyrocarbon and thermal parameters of the process of pyrolysis of hydrocarbon gases is proposed; a method for determining the density of the pyrocarbon coating on the dispersed material is developed; conducting a series of experiments on different installations with ETFB the optimal temperature (1500 °C) and the design of the reactor with ETFB for the yield of 98 % vol. hydrogen during the methane pyrolysis reaction are determined; the design of the reactor with ETFB for processing dielectric material by using a combined method of heating is improved; for the first time the temperature of ETFB 3070 °C is experimentally reached; for the first time the formation of silicon carbide from enriched pyrocarbon quartz sand during hightemperature treatment in a reactor with ETFB is experimentally proved; the fundamental possibility of applying a pyrocarbon coating in ETFB on the model of microspherical nuclear fuel, which in their physicochemical properties are close to dispersed nuclear fuel (Dy2O3, Gd2O3, Sm2O3) is experimentally proved; the method of calculating the heat balance for thermochemical processes in a typical reactor with ETFB is improved, during the experimental studies the adequacy of this technique was confirmed; When testing prototypes of extruded gaskets made of thermally expanded graphite (based on graphite purified in ETFB), it was determined that their mechanical strength corresponds to the previously used gaskets of the company "Hydropress" (RF). The research results open up prospects for the creation of energy-efficient and environmentally friendly technology for cleaning natural and artificial graphite; can be used in the creation of hydrogen production for both the chemical industry and metallurgy (high-temperature hydrogen-containing gas); open the prospect of creating an energy-efficient technology for obtaining high-purity fine silicon carbide. The obtained experimental dependences of the structure of pyrocarbon coating on the thermal parameters of the process and the study of its material characteristics open a wide prospect of application of the obtained pyrocarbon coatings in chemical technology, energy, and various high-tech industries. The obtained results on the application of pyrocarbon coating on dispersed materials with high density have the prospect of application in special metallurgy. The results of research on the manufacture of sealing gaskets from thermally expanded graphite were transferred to the Separate subdivision "Atomenergomash" of the State Enterprise "National Energy Company "Energoatom" for the creation of a production site. Full development of the entire cycle of production of thermally expanded graphite seals will eliminate the country's import dependence in this area and increase the safety of domestic nuclear power plants. Die Dissertation ist auf die Lösung des wichtigen issenschaftstechnischen Problems der Ausarbeitung der wissenschaftstechnologischen Grundlagen von Hochtemperaturprozessen (600 – 3000 °C) in der elektrothermischen Wirbelschicht (ETWS) mit Erzeugung des Reingraphits, des wasserstoffhaltigen Hochtemperaturgases, der pyrolytischen Kohlenstoffschicht, des pyrolytischen Graphits und des reinen Siliziumcarbids gerichtet. Die gestellten Aufgaben wurden durch theoretische und experimentale Verfahren zur Untersuchung der Hochtemperaturprozesse in der ETWS gelöst. Zur Analyse der Effektivität von Wärmeprozessen und Betriebsweisen werden die thermodynamischen Verfahren, Verfahren der Theorie des Wärme- und Massenaustausches, Verfahren der Ähnlichkeitstheorie verwendet. Unter den wichtigen wissenschaftlichen Ergebnissen ist es hervorzuheben: es wurde eine Möglichkeit der Hochtemperaturreinigung des Naturgraphits der Lagerstätte Zavaliye in der ETWS theoretische und experimental nachgewiesen; aufgrund der thermodynamischen Berechnungen sind wärmetechnische Haupteigenschaften der Hochtemperaturprozesse bestimmt, die zweckmäßig ist in der ETWS durchzuführen; aufgrund der thermodynamischen und wärmetechnischen Berechnungen wurden Grundparameter festgestellt, die zur Ausarbeitung und Konstruierung neuer Ausrüstung mit der ETWS notwendig sind; es wurde den Park der experimentalen Ausrüstung zur Untersuchung der thermochemischen Hochtemperaturprozesse aufgrund der experimentalen Daten geschaffen und unter Verwendung der modernen mikroskopischen Ausrüstung wurde die Abhängigkeit zwischen der Struktur des pyrolytischen Kohlenstoffs und den wärmetechnischen Parametern des Pyrolyseprozesses von Kohlenwasserstoffgasen bestimmt; es wurde das Verfahren zur Bestimmung der Dichte der pyrolytischen Kohlenstoffschicht auf einem Dispersionsstoff ausarbeitet; durch die Serie der Experimente auf verschiedenen technologischen Anlagen mit der ETWS wurden die optimale Temperatur (1500 °C) und der Aufbau des Reaktors mit der ETWS zur Erzeugung des 98 %-reinen Wasserstoff bei der Pyrolyse des Methans bestimmt; es wurde der Aufbau des Reaktors mit der ETWS zur Bearbeitung eines dielektrischen Stoffs durch Verwendung des kombinierten Erwärmungsverfahrens verbessert; zum ersten Mal wurde die Temperatur der ETWS 3070 °C erreicht; zum ersten Mal wurde die Bildung des Siliziumcarbids aus dem verkapselten mit dem pyrolytischen Kohlenstoff Quarzsands bei der Hochtemperaturbearbeitung im Reaktor mit der ETWS experimental nachgewiesen; es wurde eine prinzipielle Möglichkeit des Auftragens der pyrolytischen Kohlenstoffs in der ETWS auf Modelle des Mikrowärmeentwicklungselements, die nach ihren physikalisch-chemischen Eigenschaften einem Dispersionskernbrennstoff (Dy2O3, Cd2O3, Sm2O3) ähnlich sind, experimental nachgewiesen; es wurde die Methodik der Berechnung der Wärmebilanz zur Durchführung von thermochemischen Prozessen im Wärmereaktor mit der ETWS verbessert, die Angemessenheit dieser Methodik wurde während der experimentalen Untersuchungen bestätigt; beim Test der Versuchmuster der gepressten Dichtungen aus dem thermoerweiterten Graphits (erzeugt aus dem gereinigten in der ETWS Graphit) wurde es festegestellt, dass ihre mechanische Festigkeit den Kennziffern der früher verwendeten Dichtungen der Firma „Hydropress― (RF) entspricht. Die Ergebnisse der Untersuchungen eröffnen Perspektiven zum Schaffen der energieeffektiven Technologie der Reinigung des Natur- und Kunstgraphits; sie können bei der Bildung der Wasserstofferzeugung wie für die Chemieindustrie, als auch für die Metallurgie (das wasserstoffhaltige Hochtemperaturgas) verwendet werden; sie eröffnen auch die Perspektive einer Bildung der energieeffektiven Technologie der Erzeugung des hochreinen Kleindispersionssiliziumcarbids. Die erhaltenen experimentalen Daten in Bezug auf die Abhängigkeit der der Struktur des pyrolytischen Kohlenstoffs von den wärmephysikalischen Prozessparametern und die durchgeführten Untersuchungen dessen Eigenschaften aus dem Gesichtspunkt der Werkstoffkunde, die eine breite Perspektive zur Verwendung der erhaltenen pyropytischen Kohlenstoffschichten in der chemischen Technologie, Energetik und anderen hochtechnologischen Zweigen eröffnen. Die erhaltenen Ergebnisse nach dem Auftragen einer pyrolytischen Schicht auf Dispersionsstoffe mit hoher Dichte haben eine Verwendungsperspektive in der Metallurgie. Die Ergebnissen der Untersuchungen zur Herstellung von Dichtungen aus dem TEG wurden dem BU „Atomenergomash―des SU NAEG „Energoatom― zur Bildung einer Produktionsabschnitts übergeben. Eine vollständige Nutzbarmachung des gesamten Herstellungszyklus von Dichtungen aus dem TEG wird ermöglichen die Importanhängigkeit des Landes in diesem Bereich zu liquidieren und die Betriebssicherheit der einheimischen KKW zu erhöhen.