Cavities have been laser ablated in the ends of single-mode optical fibers and sealed by aluminized polycarbonate diaphragms to produce Fabry-Perot pressure sensors. Both conventional fibers and novel, multicore fibers were used, demonstrating the possibility of producing compact arrays of sensors and multiple sensors on an individual fiber 125 microm in diameter. This high spatial resolution can be combined with high temporal resolution by simultaneously interrogating the sensors by using separate laser sources at three wavelengths. Shock tube tests showed a sensor response time of 3 micros to a step increase in pressure.

Plastic optical fibres (POF) continuously gained its importance during the last decade, since they are widely used in automotive applications for optical data communications (for e.g. MOST). The application of POF for in-flightentertainment (IFE) optical networks in civil aircraft cabin areas is currently under investigation. Since it is expected that the optical networks will develop from a point-to-point network architecture to more complicated structures there will be a need for optical couplers distributing the signals to different suppliers. Typical applications would be for e.g. the distribution of optical data to IFE implemented within single seats of a seat row of an airplane. Within this work the fabrication of an optical 1x2 POF coupler by the Laser-LIGA technique is demonstrated. The Laser-LIGA technique compared to standard X-ray lithography is simpler and more cost effective. Moreover, the Laser ablation technique also allows rapid prototyping of the same structures. The POF couplers fabricated by this technology show insertion loss values down to about 5.6 dB, depending on the waveguide core material and exhibit good uniformity values in the order of 0.1 dB.

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Fuel processor / fuel cell systems for mobile applications are expected to be future mass products. Therefore, fabrication techniques are required, which can cope with high volume production at competitive pricing. Finally, the stainless steel or aluminium reactors and heat‐exchangers will be sealed by automated procedures such as laser welding, limiting the heat impact onto the catalysts applied in the reformers. Laser welding with dynamic beam forming is capable to weld the plate stacks of the heat‐exchanger reliably and mechanically stable to meet the demands of daily operation of such reactors.