High power and in particular tunable mid-infrared short pulse laser systems operating in the wavelength range between 3 µm and 11 µm have a large potential in different applications, e.g. analytics, medicine and micromaching. Up to now, those systems are only be realised by multistage set-ups consisting of bulk four or five different units, a configuration which is of course very complex, expensive with low efficiency operation. Unfortunately, this situation has not changed over the last years and there is no solution appearing.Therefore, in this proposal the development, realisation and investigation of such a highly integrated mid-infrared laser source is presented. Its layout is based on a Master Oscillator Power Amplifier (MOPA) short pulse Thulium all-fibre laser operating around 2 µm associated with a quasi-phase-matched GaAs crystal. For the MOPA pump source different integration aspects will be addressed in order to fully benefit of a waveguide device. This include the development of fibre-coupled saturable absorbers, large mode area (LMA) photonic crystal fibres (PCF) with functionalities regarding wavelength tuning capability, mode-filtering and high power operation, pump/signal combiners based on LMA-PCFs and novel concepts for fibre amplifiers with integrated core-pumping schemes. The wavelength conversion unit will be realised with integrated wavelength tunability and structural design.This MIR-laser will operate in the wavelength region from 2.5 µm to 11 µm with a pulse energy of up to 30 µJ, a pulse duration between tens to hundreds of picoseconds and a repetition rate between 50 to 250 kHz. For validation of the developed laser source tests concerning the processing of organic photovoltaic solar cell will be accomplished.The consortium represents the whole value chain including exploitation and this will significantly improve the competitiveness of related European industry and strengthen Europe's scientific and technology base.