Eurostars 2_BrightFiber_9447_Acreo Swedish ICT AB

Purpose and goal

This Eurostars project was a collaboration between four European partners to develop a prototype of a high-power fiber laser (> 2 kW) with a specific focus on high beam quality for materials processing. The project was terminated prematurely when the coordinator was purchased by another company. Acreo accomplished milestones to deliver and sub-optimize a number of passive and active fibers that were evaluated at Fraunhofer IOF. Acreo also completed an experimental sub-task targeting different materials for polymer fiber coatings at high thermal loads.

Expected results and effects

A glass composition was selected in the project start for optimum optical performance with respect to the chosen laser design. First experiments using an alternative glass previously used at Acreo were successful, whilst initial tests with the new glass composition proved to be a bigger challenge than expected due to interconnected glass chemical issues, process conditions and spectroscopic features. Acreo made a series of modifications to the process / glass composition that gave important knowledge and improvements (unpublished data), but more work remains to reach the goal.

Planned approach and implementation

An initial feasibility study on the optical fiber coating properties were planned and executed at Acreo, and reported to the project consortium. The development of the optical fibers was performed in an iterative process where glass preforms and fibers were manufactured at Acreo with feedback from other parties, particularly from Fraunhofer IOF who characterized the fiber laser performance. Two physical project meetings were held, start-up meeting at DPI GmbH in Berlin September 18, 2015 followed by a working meeting in Sweden (Acreo Hudiksvall) April 21 to 22, 2016.