Fabrication and integration of nanostructured optical devices

The main goal of this thesis is the numerical and experimental verification of the concept of nanostructured micro-optical elements integrated into an optical fibre. The elements are fabricated with a stack and draw technique. This technology, based on the wellknown method of photonic crystal fibres (PCFs) production, allows the fabrication of Nanostructured Gradient Index (nGRIN) microlenses and axicons with individual nanorods with diameter of 100-300nm. The necessary parameters of materials used in stack and draw method are described and two glasses are chosen for the nanostructured elements fabrication. The procedure of synthesis of clear and doped Poly(methyl methacrylate) (PMMA) is introduced, which will allow using PMMA in the future in stack and draw technique. Numerical simulations of a Gaussian beam focusing nGRIN microlenses attached to optical fibres are performed using a FFT BPM method. This shows that nGRIN microlenses can be described using the effective refractive index also in the case of the optical fibre illumination. The procedure of fabricating, cutting and polishing of elements 125 um in diameter and 20-60 um long is introduced and explained. Both simulation and experimental results show that the fabricated nanostructured lenses and axicons focus light for the fibre source with wavelength 1550nm

Introduction: what sort of past does our future need?

In this short introduction we set out the aims of the volume, which represents the fruits of two seminars held in the autumn of 2020. The chapters respond to one big thematic issue: how to research and understand historical societal resilience; and one big question: what sort of past does the future need? They attempt to address these through three linked themes: can history be made more relevant to modern policy in respect of environmental and climate challenges? To what extent do our various sources indicate awareness and management of risk and/or the implementation of mitigating strategies in the past? And how can we identify ‘resilience’ in the social praxis of historical agents

Formation of optical vortices with all-glass nanostructured gradient index masks

We report the development of microscopic size gradient index vortex masks using the modified stack-and-draw technique. The vortex mask has a form of flat surface all-glass plate. Its functionality is determined by an internal nanostructure composed of two types of soft glass nanorods. The generation of optical vortices with charges 1 and 2 is demonstrated.Qatar National Research Fund (NPRP8-246-1-060); Foundation for Polish Science Team Programme from the funds of European Regional Development Fund under Smart Growth Operational Programme (TEAM TECH/2016-1/1)

Numerical analysis of optical vortices generation with nanostructured phase masks

We study the theoretical formation of optical vortices using a nanostructured gradient index phase mask. We consider structures composed of spatially distributed thermally matched glass nanorods with high and low refractive indices. Influence of effective refractive profile distribution, refractive index contrast of component glasses and charge value on the quality of generation of vortices are discussed. A trade-off between waveguiding and phase modulation effects for various refractive index contrast is presented and analysed.Qatar National Research Fund (NPRP12S-0205-190047); Fundacja na rzecz Nauki Polskiej (POIR.04.04.00-00-1C74/16)