In this paper, we evaluate numerically the pump absorption efficiency in a D-shaped fiber. The study is carried out through the ray tracing method in three dimensions. The simulation results show that D-shaped fiber has higher pump power absorption when the core is place off the geometric center of the inner cladding. On the other hand, when the incidence of the pump beam is off the geometrical center of the fiber cross-section or the angle of incidence increases, the pump absorption efficiency decreases in a circular-shaped fiber, while in D-shaped fiber it is higher and is kept constant.
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An algorithm for the analysis of the double-clad fiber design is presented. The algorithm developed in the MATLAB computing language, is based on ray tracing method applied to three-dimensional graphics figures which are composed of a set of planes. The algorithm can evaluate an arbitrarily large number of ray paths calculating the corresponding pump absorption in each of the fiber elements according to the Lambert-Beer law. The beam path is evaluated in three dimensions considering the losses by reflection and refraction both at the fiber faces and within the fiber. Due to its flexibility, the algorithm can be used to study the ray propagation in double-clad fiber with: i) variable geometries of the inner clad and the core; ii) different position of the core inside the inner clad; and iii) bending and tapper effects.
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Currently the security of a ship would be reduced if among its systems don't have some able to indicate its position, providing the necessary data to try that the Rescue System begin a rescue in the event of emergency or catastrophe. Formerly the localization of a ship was based on warnings transmitted by the sailors or automatic systems. The efficiency of these systems was demonstrated in the rescue services and salvage of human lives obtained along more than a century. Since final of the last century the marine transport introduced a new aid system, the Global Maritime Distress Safety System (GMDSS), based in the automatic alarms through communications for satellites and the radiobeacons use that transmit data that help to the lo-calization of a ship. In this work is sought to characterize some of the systems of satellites more diffused for the localization of aid signs (INMARSAT, COSPAS-SARSAT), adding the project IRIDIUM for improvement of the search and rescue, by means of the surveillance from satellites in orbit. A comparison will be established among these systems, taking parameters like: global covering, emission of false alarms, portability and economic cost, with the objective of determining the most effective system in case of catastrophes.
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