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The University for Children is a very successful event aiming to spark children‧s interest in science, in this particular lecture in Optics and Photonics. It is from brain research that we know about the significant dependence of successful learning on the fun factor. Researchers in this field have shown that knowledge acquired with fun is stored for a longer time in the long-term memory and can be used both more efficiently and more creatively [1], [2]. Such an opportunity to inspire the young generation for science must not be wasted. The world of Photonics and Optics provides us with a nearly inexhaustible source of opportunities of this kind.
The developed solution enables the presentation of animations and 3D virtual reality (VR) on mobile devices and is well suited for mobile learning, thus creating new possibilities in the area of e-learning worldwide. Difficult relations in physics as well as intricate experiments in optics can be visualised on mobile devices without need for a personal computer.
In short-reach connections, large-diameter multimode fibres allow for robust and easy connections. Unfortunately, their propagation properties depend on the excitation conditions. We propose a launching technique using a fibre stub that can tolerate fabrication tolerances in terms of tilts and off-sets to a large extent. A study of the influence of displaced connectors along the transmission link shows that the power distributions approach a steady-state power distribution very similar to the initial distribution established by the proposed launching scheme.
Für Verbindungen über einige hunderte Meter eignen sich Multimode-Lichtwellenleiter (MM-LWL) durch ihre Robustheit und einfache Handhabung ideal. Zudem erlaubt der große Durchmesser des Faserkerns mit 62,5 µm eine sichere, stabile und relativ verlustfreie Verbindung. Neben diesen Vorteilen sind jedoch im letzten Jahrzehnt durch die Erhöhung der Bitrate auch Nachteile sichtbar geworden. So konnten die für niedrige Übertragungsraten genutzten LEDs noch zur Vollanregung der Übertragungsmoden eingesetzt werden. Für höhere Übertragungsraten ist dies jedoch nicht mehr möglich, da sie optisch zu träge sind und somit der schnellen Modulation nicht mehr folgen können. Schnellere Anregungskomponenten, etwa Laserdioden (LD), müssen eingesetzt werden. Durch die spezifische Ausstrahlungscharakteristik der LDs kann jedoch nicht mehr der gesamte MM-LWL-Kern angeregt werden. Dies führt zu unterschiedlichen Modenlaufzeiten im MMLWL, was sich wiederum negativ auf die Übertragungsrate auswirken kann. Dadurch nimmt die Bandbreite rapide ab.
Flores Nocturnas
(2012)
Nach einer Telefonkonferenz mit der weltweiten Shell-Zentrale in Houston/Texas sowie den für Europa und Deutschland zuständigen Zentralen in London bzw. Hamburg war es klar, dass der Shell Eco-Marathon in Europa durch uns live vom EuroSpeedway Lausitzring ins Internet gestreamt wird. Eine besondere Herausforderung bei diesem Live-Event lag darin, dass unser Stream per Inlineframe auf der internationalen Shell-Webseite eingebunden wurde. Ein weiteres Zeichen für das uns entgegengebrachte Vertrauen bekamen wir dann vor Ort, als wir die Eröffnungszeremonie und die Siegerehrung exklusiv übertragen durften.
Komplexe optische Netzwerke fordern eine immer größere Anzahl an permanenten und dämpfungsarmen Glasfaserverbindungen (Spleiße). Eine wichtige Voraussetzung für hochqualitative Spleiße ist eine geeignete Temperaturverteilung. Die Autoren stellen eine In-situ-Methode zur Temperaturkontrolle durch Bildbearbeitung vor.
The combination of fossil-derived fuels with ethanol and methanol has acquired relevance and attention in several countries in recent years. This trend is strongly affected by market prices, constant geopolitical events, new sustainability policies, new laws and regulations, etc. Besides bio-fuels these materials also include different additives as anti-shock agents and as octane enhancer. Some of the chemical compounds in these additives may have harmful properties for both environment and public health (besides the inherent properties, like volatility). We present detailed Raman spectral information from toluene (C7H8) and ethanol (C2H6O) contained in samples of ElO gasoline-ethanol blends. The spectral information has been extracted by using a robust, high resolution Fourier-Transform Raman spectrometer (FT-Raman) prototype. This spectral information has been also compared with Raman spectra from pure additives and with standard Raman lines in order to validate its accuracy in frequency. The spectral information is presented in the range of 0 cm-1 to 3500 cm-1 with a resolution of 1.66cm-1. This allows resolving tight adjacent Raman lines like the ones observed around 1003cm-1 and 1030cm-1 (characteristic lines of toluene). The Raman spectra obtained show a reduced frequency deviation when compared to standard Raman spectra from different calibration materials. The FT-Raman spectrometer prototype used for the analysis consist basically of a Michelson interferometer and a self-designed photon counter cooled down on a Peltier element arrangement. The light coupling is achieved with conventional62.5/125μm multi-mode fibers. This FT-Raman setup is able to extract high resolution and frequency precise Raman spectra from the additives in the fuels analyzed. The proposed prototype has no additional complex hardware components or costly software modules. The mechanical and thermal disturbances affecting the FT-Raman system are mathematically compensated by accurately extracting the optical path information of the Michelson interferometer. This is accomplished by generating an additional interference pattern with a λ = 632.8 nm Helium-Neon laser (HeNe laser). It enables the FT-Raman system to perform reliable and clean spectral measurements from the materials under observation.
Nowadays, it is assumed of many applications, companies and parts of the society to be always available online. However, according to [Times, Oct, 31 2011], 73% of the world population do not use the internet and thus aren't “online” at all. The most common reasons for not being “online” are expensive personal computer equipment and high costs for data connections, especially in developing countries that comprise most of the world’s population (e.g. parts of Africa, Asia, Central and South America). However it seems that these countries are leap-frogging the “PC and landline” age and moving directly to the “mobile” age. Decreasing prices for smart phones with internet connectivity and PC-like operating systems make it more affordable for these parts of the world population to join the “always-online” community. Storing learning content in a way accessible to everyone, including mobile and smart phones, seems therefore to be beneficial. This way, learning content can be accessed by personal computers as well as by mobile and smart phones and thus be accessible for a big range of devices and users. A new trend in the Internet technologies is to go to “the cloud”. This paper discusses the changes, challenges and risks of storing learning content in the “cloud”. The experiences were gathered during the evaluation of the necessary changes in order to make our solutions and systems “cloud-ready”.