The LMTB has designed and implemented a novel optical concept for the development of a versatile trepanning system, enabling the adjustment of the displacement and the inclination angle during circular rotation at up to 20000 r.p.m. The presented trepanning systems are able to laser machine through-holes diameters of 100 µm with a negative taper of up to 5°. Starting from an early stage of implementation, the novel trepanning system has been customized for different applications and industrial partners. The conference paper outlines the development steps and advanced performance, accenting laser micro machining results utilizing the novel LMTB trepanning system in operation at different laser parameters.

Many laser material processing applications require an optimized beam profile, e.g., ring shape or Top-Hat profiles with homogeneous intensity distribution. In this study, we show a beam shaping concept leading to a phase shifting element with binary height profile as well as a very low periodicity with near diffraction limited spot size. Further advantages of so-called Fundamental Beam Mode Shaping (FBS) elements are the simplified handling, and a high efficiency and homogeneity. The calculated height profile of FBS elements are transferred in fused silica substrates using a combination of microlithography technologies, reactive ion etching (RIE) and ion beam etching (IBE). The experiments demonstrated a linear relation between the etching depth after RIE and IBE. The optical evaluation of the manufactured FBS beam mode shaper confirmed the presented concept design.

Especially for micro machining lasers have opened new possibilities which were not accessible by traditional mechanical processes (e.g. intravolume glass marking). For many applications the raw Gaussian laser beam profiles are not optimal adapted for material processing. Therefore optimized beam profiles like those with homogeneous intensity (so called Top Hat) or with ring shape are often desired to enhance process efficiency and quality.

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Within in the last years the average power of industrial pulsed laser systems is continuously increasing. However one can often not make efficient use of the available power, since the laser process limits the pulse energy which can be applied to the work piece. In particular for ultrashort pulsed laser (USP) processing the maximum pulse energy is further limited due to plasma shielding effects. For those reasons laser processing often is too slow and too expensive (when available laser power cannot fully be used), thus is an uneconomical solution even if process results are excellent. How to overcome such limits?