Robert Evert

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This paper presents an improvement for an automatic extrinsic parameter calculation between a monocular camera and single line laser range finder. The focus of this work is a further reduction of calibration errors compared to other existing methods, and the unique and automatic identification and detection of a calibration object under usage of the(More)
Polymer optical fibers are a very good choice for flexible and robust short range optical data links. We have developed PMMA with Eu<sup>3+</sup>-doped polymer chains. From this optically active material we draw fibers. These fibers can be used for UV pumped polymer fiber amplifiers in cases where larger distances have to be bridged. This paper presents the(More)
A universal simulation model for rare earth doped cw fibre lasers is presented. The model is based on generic rate and gain equations and therefore is very compact. It can be used for any fibre doped with one or several rare earth ions. The model allows for spectral simulations as well as radial discretization of the fibre. An algorithm was developed which(More)
We model the light amplification in Eu-doped PMMA polymer optical fibers by solving our own rate equations that describe the physical system. These equations are firstly solved in stationary state, for a constant pump power. In this case, we determine the optimum fiber length for maximum output power. We also solve the time-dependent equations to be able to(More)
Waveguides made of poly-methyl-methacrylate (PMMA) play a major role in the homogeneous distribution of display backlights as a matrix for solid-state dye lasers and polymer optical fibers (POFs). PMMA is favored because of its transparency in the visible spectrum, low price, and well-controlled processability. Nevertheless, technical drawbacks, such as its(More)
The mechanical properties of polymer optical fibers (POF) make them very interesting candidates for fiber optical sensors. Today POFs are mainly used for short range data communication. These fibers have a very large core of 980 &#x03BC;m. This large core is beneficial for handling and maintenance in fiber networks. Fiber sensors however, often need high(More)
The ratio of electrical conductance measured at two frequencies can be used to predict the cold hardiness of stem sections of Cornus stolonifera Michx. during the first stage of cold acclimation. Electrical conductance at 50 hertz divided by electrical conductance at 100 kilohertz gave a better estimate of hardiness than measurements at either frequency(More)
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