Optical Engineering

A defocused transfer function of experimental microscopic bright-field images, closely connected with the evaluation of the relative refractive index profile of axially symmetric optical fibers, is presented. It is shown that with this function it is possible to obtain, with high precision, the defocused bright-field images of investigated fibers from their focus images and then to easily evaluate the relative refractive index profiles of the fibers.

Advanced modulation formats can enable >40 Gb/s data rates in waveguide-based optical interconnects without the need for high-specification optoelectronic components. Record 56Gb/s PAM-4 data transmission is demonstrated over a 1 m-long multimode polymer waveguide.

Laser-induced breakdown spectroscopy (LIBS) has been used to study the surface hardness of special aluminum alloys containing zeolite. The aluminum alloy has acquired pronounced changes in its metallurgical properties due to the zeolite inclusion. The surface hardness of the samples under investigation is determined by measuring the spectral intensity ratios of the ionic to atomic spectral lines in the LIBS spectra of samples having different surface hardness values that have been conventionally measured before for comparison. The presence of aluminum silicate mineral in the studied alloys enabled material volume to expand under compression. This feature gave new results in the measurement of hardness via LIBS. It has been proven that the trend of the alloy density change complies with the increase of ionic to atomic spectral line intensity ratio.

Artur Dybko, Światłowodowy czujnik do pomiaru stężenia jonów hydroniowych, Praca dyplomowa magisterska, Instytut Podstaw Elektroniki, Politechnika Warszawska, 1990  (okładka, spis treści, dedykacja)
Wstęp,
Przegląd konstrukcji pH-metrów światłowodowych,
Wybór metody pomiarowyej,
Wyniki prac doświadczalnych,
Sugestie dalszych prac,
Dodatek chemiczny
Literatura.

Versatility in the design of optical systems is one of the key features of light-emitting diodes (LEDs) that has attracted considerable attention. In the analysis of systems using LEDs, it is useful to know if the distance is far enough from the LED to allow the radiation pattern to be simulated by the point source approach. We propose three far-zone conditions for LED light modeling: the far-field distance, and for practical purposes the quasi far-field and minimum far-field distances. Different types of LEDs have different far-field ranges. We analyze these differences by modulating key parameters like geometrical structure of encapsulating lens, chip size, chip shape, chip position, and package errors. We find that far-field region considerably depends more on the shape of both lens and chip than all other parameters.

Multi-proxy approach was used to reconstruct the environmental conditions of remote lakes in the High Tatra Mountains (Slovakia) over the past few centuries (approximately 500-1000 years). Short sediment cores (*30 cm) taken from three morphologically similar glacial lakes distributed along altitudinal gradient (subalpine to alpine conditions) were analysed for organic matter content (LOI), diatoms and chironomids. Both descriptive and correlative approaches were used for analysing stratigraphical data. Predictive canonical correspondence analysis and co-correspondence analysis were applied to directly relate physical and biological proxies to each other. The relationship between LOI and biotic proxies was inconsistent across groups and lakes. Concordant patterns in diatom and chironomid composition were found in two non-acidified lakes. Common trends in those assemblages indicated major past environmental events such as the Little Ice Age, air pollution and lake acidification. In contrast, no relationship between the composition of diatom and chironomid assemblages was found in the formerly acidified lake, suggesting different responses of assemblages to acidification. While chironomids showed shifts that are attributable to recovery, diatoms assemblage remained relatively stable throughout the uppermost layers of the sediment record. On the other hand, climatic-driven changes in assemblages detected in the deeper layers were more pronounced in diatoms than in chironomids.

Optical fiber offers many advantages over coaxial cable for the transmission of radio frequency ͑rf͒ signals in antenna-remoting applications, as well as cellular networks and cable television ͑CATV͒ signal distribution networks. Optical fiber shows significantly less loss, can support signals demanding much higher bandwidth, is immune to electromagnetic interference ͑EMI͒, and enables considerable size and weight savings when compared to coaxial cable. Free-space optics ͑FSO͒ communications is a technology that uses modulated optical beams to transmit information line of sight through the atmosphere. FSO can be deployed faster and cheaper when compared with optical fiber. Recently, FSO has been investigated by the telecommunications industry and research centers to transport digital signals for civilian "last mile" applications and military applications. We demonstrate the successful transport of modulated rf analog signals over an FSO link and compare key performance measures against a fiber optic link configured in an identical manner. Results of measurements of optical power, transmission response, reflection response, group delay that defines phase distortion, carrier-to-noise ratio ͑CNR͒, and dynamic range that defines nonlinear distortion are presented. Results from this comparative study indicate that FSO for rf applications is a suitable replacement for fiber optic transmission links over short distances.

Statistical learning theory explores ways of estimating functional dependency from a given collection of data. The specific sub-area of supervised statistical learning covers important models like Perceptron, Support Vector Machines (SVM) and Li-near Discriminant Analysis (LDA). In this paper we review the theory of such models and compare their separating hypersurfaces for extracting group-differences between samples. Classification and reconstruction are the main goals of this comparison. We show recent advances in this topic of research illustrating their application on face and medical image databases.

Recent measurement campaigns in Prague, Czech Republic have recorded the specific attenuation caused by fog in terrestrial freespace optical (FSO) links along with visibility, liquid water content (LWC), and integrated particle surface area for operational wavelengths of 1550 and 830 nm. Data recorded during 5 months of measurements has been analyzed in an attempt to validate and improve the empirical models for LWC and visibility-based attenuation and the probability density function (PDF) estimation of the received signal strength (RSS). The results strongly suggest that further attempts in refinement of the empirical modeling for visibility-based attenuation or LWC-based attenuation shall move towards the establishment of a global data bank of fog attenuation measurements in different climatic regions. This data bank can then help develop generic models which could lead to better system design of future terrestrial FSO links. The PDF estimation of RSS puts forth the Kumaraswamy distribution as the best fit for settled continental fog conditions.

This paper describes the basic technological aspects of Digital Image Processing with special reference to satellite image processing. Basically, all satellite image-processing operations can be grouped into three categories: Image Rectification and Restoration, Enhancement and Information Extraction. The former deals with initial processing of raw image data to correct for geometric distortion, to calibrate the data radiometrically and to eliminate noise present in the data. The enhancement procedures are applied to image data in order to effectively display the data for subsequent visual interpretation. It involves techniques for increasing the visual distinction between features in a scene. The objective of the information extraction operations is to replace visual analysis of the image data with quantitative techniques for automating the identification of features in a scene. This involves the analysis of multispectral image data and the application of statistically based decision rules for determining the land cover identity of each pixel in an image. The intent of classification process is to categorize all pixels in a digital image into one of several land cover classes or themes. This classified data may be used to produce thematic maps of the land cover present in an image.

We present theoretical and experimental investigations of threeterminal nanoelectromechanical relays based on suspended carbon nanotubes. A charge is induced in the nanotube by applying a voltage to an underlying gate electrode thus inducing the nanotube to bend and make contact with a drain electrode. Such devices have potential applications as fast switches, logic devices, memory elements and pulse generators. We describe two modes of operation: a contact mode where the nanotube makes physical contact with the drain electrode and a non-contact mode where electrical contact between the nanotube and the drain electrode is made via a field emission current.

Suppose that a random process Z(s; t), indexed in space and time, has a spatio-temporal stationary covariance C(h; u), where h 2 IR d (d 1) is a spatial lag and u 2 IR is a temporal lag. Separable spatio-temporal covariances have the property that they can be written as a product of a purely spatial covariance and a purely temporal covariance. Their ease of de nition is counterbalanced by the rather limited class of random processes to which they correspond. In this article, we derive a new approach that allows one to obtain many classes of nonseparable, spatio-temporal stationary covariance functions and we t several such to spatio-temporal data on wind speed over a region in the tropical western Paci c ocean.

Chalcogenide glasses are promising candidate materials for a wide range of photonics applications. The design and realisation of optical components based on these materials requires detailed information on their optical properties, frequently over a range of wavelengths. In this paper we review experimental refractive index data for three chalcogenide glass compositions, and discuss how various numerical fits to the data prove useful within electromagnetic simulation tools.

The plastic substrates, reflective layers, dyes, and adhesives of four archival-grade, recordable DVDs and one standard-grade recordable DVD were analyzed to determine their chemical compositions and/or physical dimensions. Chemical analyses by ATR-FTIR, ToF-SIMS, XPS, EDX/STEM, and RBS show that all these DVDs use very similar polycarbonate plastic substrates and acrylate-based adhesives, but different reflective layers and dye write layers. In addition, physical measurements by AFM show differences in the DVD groove depth, width, and other dimensions. These chemical and physical analyses may help explain variations in DVD lifetimes and facilitate development of the next generation archival-grade DVDs.

The MirraMirra case is a must have! A stylish case with a slide out mirror. Keeping you looking your best wherever you go. I'm proud to announce this fantastic new product called the MirraMirra iphone tablet which I was asked to develop and engineer the optical wave-guide fibre optic system so that no additional power source is required to make the light source operate. The paper documents the R&D and the design process it went through.
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In this paper, I reviewed comprehensively the structure and operation of closed-loop IFOGs, Feedback Erbium-doped fiber amplifier (EFDA) FOGs, called FE-FOG. The procedure of finding the Sagnac shift for closed-loop IFOG has been studied. The signal processing in the closed-loop IFOG was simulated using PSCAD software. In the closed-loop IFOG, the phase shift was derived through frequent use of Sagnac loop. The output signal is injected in the input again as feedback. The shift phase between clockwise and counterclockwise waves in each complete route, including primary and feedback route, is identified as Sagnac shift phase. According to Sagnac shift phase we could determine angular rotation rate.

The field of digital image processing is reviewed with reference to its origins, progress, current status, and prospects for the future. Consideration is given to the evolution of image processor display devices, developments in the functional components of an image processor display system (e.g. memory, data bus, and pipeline central processing unit), and developments in the software. The major future trends include: increased performance through very large scale integration and integral array processors, the use of the optical video disc as an image storage medium, and automatic image analysis.

Multi-proxy approach was used to reconstruct the environmental conditions of remote lakes in the High Tatra Mountains (Slovakia) over the past few centuries (approximately 500-1000 years). Short sediment cores (*30 cm) taken from three morphologically similar glacial lakes distributed along altitudinal gradient (subalpine to alpine conditions) were analysed for organic matter content (LOI), diatoms and chironomids. Both descriptive and correlative approaches were used for analysing stratigraphical data. Predictive canonical correspondence analysis and co-correspondence analysis were applied to directly relate physical and biological proxies to each other. The relationship between LOI and biotic proxies was inconsistent across groups and lakes. Concordant patterns in diatom and chironomid composition were found in two non-acidified lakes. Common trends in those assemblages indicated major past environmental events such as the Little Ice Age, air pollution and lake acidification. In contrast, no relationship between the composition of diatom and chironomid assemblages was found in the formerly acidified lake, suggesting different responses of assemblages to acidification. While chironomids showed shifts that are attributable to recovery, diatoms assemblage remained relatively stable throughout the uppermost layers of the sediment record. On the other hand, climatic-driven changes in assemblages detected in the deeper layers were more pronounced in diatoms than in chironomids.

Ryszard Romaniuk (Warsaw University of Technology), Praca stanowi wprowadzenie do wybranych zagadnień obecnego stanu wiedzy w zakresie teorii, technologii i zagadnień aplikacyjnych światłowodów kształtowanych. Jest przeznaczona dla studentów elektroniki i fizyki, doktorantów, inżynierów praktyków i pracowników naukowych, którzy pragną poznać, w aspektach podstawowych i stosowanych, tą stosunkowo nową i dynamicznie rozwijającą się dziedzinę fotoniki światłowodowej. Zamierzeniem autora jest, przy pomocy tej pracy, podjąć próbę rozszerzenia znajomości techniki światłowodów kształtowanych wśród szerszego kręgu inżynierów. W celu osiągnięcia tego zamierzenia przedstawiono wyczerpująco poszczególne zagadnienia teoretyczne, analityczne, projektowe, technologiczne, konstrukcyjne i aplikacyjne w kontekście fizycznym, chemicznym i technicznym starając się utrzymać pełną precyzję dyskusji naukowo-badawczej.
Technika światłowodów kształtowanych oferuje znacznie szerszy wybór narzędzi projektowania samego włókna optycznego i następnie wykonywanych z niego elementów i urządzeń światłowodowych, niż klasyczna technika światłowodów telekomunikacyjnych. Cena, którą płacimy za rozszerzenie swobody projektowania są znacznie większe straty jednostkowe światłowodów, gorsze właściwości mechaniczne i słabsza stabilność chemiczna. Świat praktycznych zastosowań włókien optycznych nie zdecydował jeszcze obecnie czy jest to cena warta zapłacenia. Niniejsza praca, poprzez szeroką analizę aktualnych problemów badawczych i technicznych, próbuje znaleźć kilka nowych przyczynków do takiej, ewentualnie pozytywnej, odpowiedzi. W najszerszym ujęciu, autor próbuje odpowiedzieć na pytania dotyczące „konkurencji” w zastosowaniach światłowodów telekomunikacyjnych i kształtowanych. Czy nominalne charakterystyki światłowodów kształtowanych predestynują je do zastosowań np. w trudnych warunkach środowiskowych w przemyśle, w technice wojskowej, motoryzacyjnej, lub fotonicznych systemach monitorowania stanu rozległych technicznych systemów municypalnych a także stanu środowiska naturalnego.

Proposed is silicon-photonics-based phased array antenna beamforming for high-resolution long-range radars with wide instantaneous radio frequency ͑rf͒ bandwidth. Specifically, the proposed siliconphotonics beamformer platform offers the potential for cost-effective monolithic chip-scale integration of photonic delay lines, 2 ϫ 2 optical switches, variable optical attenuators, and optical amplifiers that form the base unit of a rf transmit/receive array signal processor. In effect, the proposed silicon-photonics devices empower the design of a powerful proposed photonic beamformer with one time-delay unit per antenna element. Device-level designs studies are shown that promise meeting the high-resolution radar mission-critical requirements via time delays of up to 2.5 ns, switching times of less than 100 ns, optical isolations as good as 50 dB, and optical gains of up to 6 dB. Longer delays are achieved off chip using optical fibers. © 2010 Society of Photo-Optical Instrumentation Engineers.

Thermal, mechanical, and optical properties of Cleartran ® multispectral zinc sulfide were measured. Heat capacity, thermal conductivity, and thermal expansion were measured over the temperature range 213 to 643 K. Young's modulus and shear modulus were measured at 289 to 473 K. The characteristic four-point flexure strength for a 1-cm 2 area was 75.4± 0.5 MPa at 289 K and 89.5± 0.4 MPa at 473 K, with Weibull moduli of 11.0± 0.7 and 19.3± 1.5, respectively. All 24 specimens tested at 289 K conformed to the Weibull curve. However, 2 of 23 specimens tested at 473 K had low, outlying strengths. The fracture origins of the outliers were surface flaws that were not detected by microscopic examination prior to mechanical testing. The only reliable means that we are aware of to identify weak material is a mechanical proof test. Infrared transmittance and reflectance at 297, 373, and 473 K were measured with an integrating sphere. The transmittance of s-and p-polarized infrared light was measured at angles of incidence of 0 to 60 deg. By fitting the transmittance with the Fresnel equations, the absorption coefficient was computed for wavelengths of 8 to 14 m. Bidirectional transmittance and reflectance distribution functions ͑optical scatter͒ were measured at 3.39 and 10.6 m.

A novel optical system that combines a polarimetric current sensor based on the Faraday effect, and a voltage sensor based on the Pockels effect, is described. The proposed device uses polarizers that possess high polarization ratios in specific spectral ranges. This allows the simultaneous codification of current and voltage information in different spectral regions, which, in turn, enables independent measurements of both magnitudes. Validation experiments are presented.

Glasses, either pure or suitably doped, constitute an excellent material for the development of integrated optical circuits. A brief review is presented of the most widely used processes for the fabrication of passive and active glass waveguides. Brilliant prospects of glass-based platforms for the development of photonic integrated circuits are outlined. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

Little has been published (particularly in English) on the type of print known as the perspective view, intended for use in an optical diagonal machine. Nevertheless these prints were highly popular in the eighteenth and nineteenth centuries, and still appear regularly on the art market. lt therefore seems worth collecting what information is known and adding what I have been able to discover. 1 This article opens with a discussion of the various types of optical diagonal machine and how they function. This is followed by a brief sketch, based on material taken from eighteenth- and nineteenth century catalogues and household inventories, of the social classes who owned thern. The final section is devoted to an examination of the different characteristics of the perspective views produced in the four main centres, London, Paris, Augsburg and Bassano: particular attention is paid here to two draughtsmen who worked for publishers in Augsburg.

The purpose of this exploratory study is to better understand the current dynamics of the Malaysian market for smartphone and the usage behaviors of consumers. This paper presents the result of a survey on the trend of smartphone from the perspective of end consumers. The data was collected from 1814 respondents across major cities in Malaysia. This study has looked into the familiarity of users towards smartphones, choices of smartphone brand and service providers, and most importantly the determinants that influence their purchasing decision. Additionally, the consumers' preferences on smartphone specifications such as design, computing power, operating platform, and price were investigated. Furthermore, consumers' usage behaviors such as using smartphone for email, web browsing, gaming, and document reading were examined. The statistics presented provides fundamental information regarding the trends in the smartphone market and usage behaviors in Malaysia. Such information are useful for academics for the development of future works in the field, whereas for smartphone manufacturers, application developers and other stakeholders, they are able to plan their direction in the Malaysian smartphone market.

This book is a MUST for everyone in and around the optics community! Fiber Optic Essentials provides professionals and students new to the field of fiber optics with a high-level knowledge of principles, theories and applications. This primer can also be used as a succinct overview of optics for those with some engineering and physics background.

The WILGA Symposium has become a permanent important scientific
event in the landscape of young science in Poland. Organized
over the last quarter of a century, the WILGA Symposium covered
thematically photonics, optoelectronics, modern electronic systems
in terms of design, hardware, technology, construction, programming
and operation. The main topics were optoelectronics, photonics,
optical engineering and their integration into larger systems
and functional environments with electronics, telecommunications
and mechatronics. The participants of the WILGA Symposium are
mainly doctoral students and graduate students from polytechnic
universities from the faculties of electronics, mechatronics, technical
physics, and materials engineering. In the pre-pandemic period, over
400 people attended the WILGA Symposium each year. The WILGA
Symposium is organized in two editions per year, winter in January
and spring at the turn of May and June. In recent years, an autumn
session has also been organized in September. The materials of the
WILGA Symposium have been published since 2002 in the conference
series Proceedings of SPIE. The WILGA Symposium was attended
by several thousand doctoral and graduate students from all over
Poland, often accompanied by their tutors. The publication output of
the WILGA Symposium includes over 2,000 scientific and technical
articles published in indexed bibliometric databases such as Scopus
and Web of Science, as well as in the Elektronika monthly and the PAN
IJET quarterly. The jubilee edition of WILGA Symposium is planned in
September 2022.

International Journal of Microwave Engineering (JMICRO) is a peer-reviewed, open access journal which invites high quality manuscripts that focuses on Engineering and theory associated with microwave / millimeter-wave technology, guided wave structures, electromagnetic theory and implementation. Authors are invited to submit original research works that stimulate the development of latest technology in industry and academia. Good quality review papers and short communications are also acceptable. Research areas suitable for publication include, but are not limited to the following fields:

Image compression is an important component in modern imaging systems as the volume of the raw data collected is increasing. To reduce the volume of data while collecting imagery useful for analysis, choosing the appropriate image compression method is desired. Lossless compression is able to preserve all the information, but it has limited reduction power. On the other hand, lossy compression, which may result in very high compression ratios, suffers from information loss. We model the compression-induced information loss in terms of the National Imagery Interpretability Rating Scale or NIIRS. NIIRS is a user-based quantification of image interpretability widely adopted by the Geographic Information System community. Specifically, we present the Compression Degradation Image Function Index (CoDIFI) framework that predicts the NIIRS degradation (i.e., a decrease of NIIRS level) for a given compression setting. The CoDIFI-NIIRS framework enables a user to broker the maximum compression setting while maintaining a specified NIIRS rating.

It has been a challenge to finish optical glass surface due to their hard and brittle nature. Moreover tight tolerances of surface figure and finish make polishing a more critical operation. This work reports the results of an experimental study performed for full aperture polishing of BK7 optical glass. Flat samples of BK7 glass are polished using optical pitch polisher and cerium oxide slurry. Taguchi’s L9 orthogonal array is used for design of experiments. Abrasive concentration, pressure and overarm speed are taken as variable process parameters. Polishing is performed for duration of 120 minutes for each combination of parameters. Material removal is measured using the precision weighing balance. Surface roughness was measured using Form Talysurf PGI 120 profiler. Abrasive slurry concentration is observed to be one of the most significant parameters in optical polishing process. It affects material removal rate as well as surface roughness. Pressure applied at workpiece-polisher interface affects material removal rate but variation of pressure is not found to affect surface roughness significantly. Relative motion at workpiece-polisher interface is also observed to be significant in defining final polishing outputs.

The ISO 9001 (2000) define "Quality" as the ability of a set of inherent properties and characteristics of a product, system or process to fulfill requirements of customers and other interested parties. The "Plan de Calidad de Obra (PCO)" is an instrument that follows to get the necessary quality in Civil Works contracts. Graphical documentation generated during construction project elaboration or even during Civil Engineering works execution with planes, makes obligatory a meticulous treatment of this information that results transcendental in the consecution of the definitive products (projects or works) quality objective. In this work it's shown the principal graphical documentation procedures defined in the PCO attending to the edition, modification, distribution, storage, and other relevant aspects related to graphical information.