Correlation optics in progress: introduction to the feature issue

This feature issue of Applied Optics contains a series of selected papers reflecting recent progress of correlation optics and showing, in part, the trend from micro-optics to nano-optics

Fabrication of corrugated Ge-doped silica fibers

We present a method of fabricating Ge-doped SiO2 fibers with corrugations around their full circumference for a desired length in the longitudinal direction. The procedure comprises three steps: hydrogenation of Ge-doped SiO2 fibers to increase photosensitivity, recording of Bragg gratings with ultraviolet light to achieve modulation of refractive index, and chemical etching. Finite-length, radially corrugated fibers may be used as couplers. Corrugated tapered fibers are used as high energy throughput probes in scanning near-field optical microscopy

Performance of Scanning Near-Field Optical Microscope Probes with Single Groove and Various Metal Coatings

We investigate the performance of a simple corrugated aperture scanning near-field optical microscope (SNOM) probe with various cladding metals. The probes have only one corrugation, however, they offer increased transmission over both uncorrugated probes and those with many grooves. Enhancement of light throughput results from excitation of surface plasmons at the corrugation at the core–cladding interface. We show how the choice of metal influences radiation properties of grooved probes

Application of Artificial Neural Networks for load prediction in a gas pipeline network

Zaproponowano zastosowanie metody sztucznych sieci neuronowych do prognozowania obciążenia sieci gazowej przykładowego miasta w Polsce, biorąc pod uwagę czynniki pogodowe oraz kalendarzowe. Na podstawie rzeczywistych danych wejściowych wytrenowano wiele sieci neuronowych, różniących się liczbą neuronów w warstwie ukrytej i zaproponowano najlepszą strukturę sieci neuronowej, która zależy od liczności zbioru danych wejściowych. Otrzymane modele sieci mogą być z powodzeniem stosowane w praktyce.Application of Artificial Neural Network for load prediction in a gas pipeline network in an exemplary Poland city taking into account weather and calendar factors is proposed in the paper. Based on real data, a number of neural networks with a various number of neurons in hidden layer were trained. The best neural network structure depending on a number of initial data sets was proposed. The obtained network models can be successfully applied in practice

Model and implementation of inteligent information system of e-Bureau

The paper presents selected results of model and implementation research concerning the design of a management information system (MIS) to support the functioning of office administration offering sale of services. The application was tested with view to implementation in the Association for Promotion and Scientific Innovations Implementation (AP&SII or Association). The following issues were discussed: methods of organization management modelling, suitable software, available tools supporting modelling, methods of implementation of models in organization systems, etc. E-Bureau information system is an application developed using Eclipse platform with the following plug-ins installed, namely Data Base Development Tools and PHP Development Tools. The system is based on libraries, i.a. Zend, BootStrap, JQuery. The following programming tools were used: CSS, JavaScript, HTML, PHP

The study of airlift reactor hydrodynamics

Analizowano udział gazu zatrzymanego w cieczy w strefie wznoszenia i opadania, prędkość cieczy w strefie wznoszenia i opadania oraz czas mieszania w kolumnie air-lift z zewnętrzną cyrkulacją płynu. Badano układy woda-powietrze oraz roztwór gliceryny-powietrze dla różnych objętościowych strumieni powietrza. Wykazano, że w zakresie przeprowadzonych pomiarów typ układu ciecz-gaz miał wpływ na prędkość cieczy w strefie wznoszenia i opadania oraz czas mieszania, a nie wpływał istotnie na wielkość udziału gazu zatrzymanego w cieczy.The gas hold-up and liquid velocity in a riser and downcomer as well as mixing time in the external-loop airlift reactor were analyzed. Two systems: air – water and air – glycerol in water solution for various volumetric gas flow rates were investigated. It was proved that in the range of performed measurements a type of gas – liquid phase affects the liquid velocity in a riser and downcomer and mixing time but does not significantly affects gas hold-up