Ultra-fast lasers have already been used to machine rotational symmetric metallic parts for several years but did not prevail against much cheaper fiber lasers. The limiting factor up to now is the dynamics of the rotary and linear axes, that are used to move the part underneath the stationary laser beam. Although the quality of the surface machined with ultrafast pulsed laser radiation is better than that machined with fiber laser radiation, an overall economic consideration mostly did not justify the utilization of ultrafast pulse lasers for this kind of application. Therefore, new and innovative concepts are needed to exploit the potential of ultrafast pulse lasers, in particular high repetition rate and the steadily increasing average power. The realization that will be presented uses a high-end galvanometric scanner to move the laser beam at speeds of several ten meters per second across the constantly rotating part. The most important part is the synchronization of the laser, the scanner and the axes.

A real case study and characterisation of modern energy efficient windows allowing mobile communication is presented. An earlier study had shown that laser scribing of energy saving coatings allows highly reducing the microwave attenuation (from 30 to 1–3 dB) using a wide band-pass frequency-selective surface (FSS) while preserving the thermal quality of the window. To achieve large-scale production, the laser scribing technique has been further developed. The effect of laser scribing on the mechanical properties of a substrate has been determined through mechanical strength tests. Moreover, the insulating properties of the window have been analysed to ensure the reliability of this technology. As a real case demonstration, an entire train has been equipped with prototype windows. The signal quality has been controlled for a wide band of frequencies and for existing technologies such as long term evolution, universal mobile telecommunication system, multiple input multiple output and for different configurations such as a stationary and a moving train.

High-power and high-energy µs pulsed lasers are well-known for drilling applications like cooling holes in turbines, metallic filters such as fuel filters, or for the delivery of fluids such as de-icing in aerospace. Drilling strategies are single pulse drilling, percussion- or trepan drilling. Typically the aspect ratio (depth/diameter) of the holes is in the range of <20:1. Holes with diameter <100 µm and aspects ratios >20:1 have been reported.In this paper we talk about holes of diameters <150 µm and aspect ratios up to 100:1, drilled with “thermal” pulses achieved by high-power long-pulse fiber lasers.Taking into account the depth of focus of the beam some beam guiding mechanism in the hole has to be present to reach such aspect ratios. The experiments show that, for high pulse repetition rate with high focal intensity, a stable plasma column is observed in the hole for optimized laser parameters. As soon the plasma column is extinguished drilling is stopped and cannot be restarted. We speculate that the beam guiding is accomplished either by a highly reflecting melt film on the hole walls due to heat conductivity from the plasma to the wall or by nonlinear beam guiding mechanism of the dense plasma.

A prerequisite for laser material processing of copper is direct interaction between the focused laser radiation and the copper surface that requires part of the radiation to be absorbed at the surface. As FIGURE 1 shows, for a polished copper surface at room temperature, less than 5% of the laser radiation is absorbed (at 1 μm laser wavelength). Despite this, there are a range of measures that can be taken to allow copper to be welded successfully and efficiently, particularly with solid-state or fiber lasers.

This paper gives an overview of the new possibilities offered by the pulsed fibre laser technology with a particular focus on welding applications.