Jan Dolkemeyer

Soldering techniques for the assembly of high power solid-state lasers

Soldering techniques are of increasing interest for the manufacturing of laser systems. High thermal conductance required for effective and long-term-stable cooling of laser components and a low sensibility to environmental influences like temperature changes and humidity are the main reasons to join components by soldering. Compared to conventional mounting techniques, soldering demands highly complex process control. Detailed knowledge about the influence of mechanical stress caused by thermal expansion mismatch is necessary to properly choose not only the process strategy but also the dimensions of the components. This paper reports on the development of soldering techniques for the surface-mounted assembly of laser components such as lenses, mirrors, laser-crystals and nonlinear crystals used for the assembly of a miniaturized marking laser system “MicroSlab”[1].

Highly flexible ultrafast laser system with 260W average power

A flexible ultrafast laser amplifier system based on Ytterbium Innoslab technology with an average power exceeding 200W is presented. The pulse duration of the system can be continuously tuned between 500fs and 6ps, limited only by the amplification bandwidth of Yb:YAG and the stretcher of the seed source. The repetition rate can be varied from 26.6MHz down to 1MHz. For the ps-regime more than 200μJ and for the fs-regime more than 50μJ are demonstrated without the need of temporal compression of the high power beam after the amplifier. Spectral bandwidth is close to the transform limit of the shortest measured pulses. Beam quality is measured to be near the diffraction limit (M2<1.3).

Femtosecond Innoslab amplifier with 300W average power and pulse energies in the mJ-regime

We demonstrate a femtosecond Yb:YAG InnoSlab laser amplifier producing <3mJ pulse energy at 100kHz pulse repetition rate. The minimal pulse duration is <1ps resulting in pulse powers <3GW. High energy and high average power could be obtained with the use of chirped pulse amplification on the power amplifier end. The laser setup consists of a seed laser with 10mW average power at pulse repetition rates of 100kHz to 1MHz, a pre-amplifier stage, a highpower InnoSlab-amplifier stage and a grating based pulse compressor. This laser source is suited for pumping of OPCPA setups und parallelisation of applications in materials processing.