High-brightness laser diode modules for Yb and Er fiber lasers

摘要

Recent progress in rare-earth doped fibers has allowed Yb-doped fiber lasers to be power-scaled to several kW's. Remarkably, the continued rise of the fiber laser output power into multi-kW range is being limited by the pump diodes rather than the fibers themselves. In this article we discuss our recent progress in the development of high-brightness fiber-coupled laser diode modules for pumping Yb and Er doped lasers. Pumps based on laser diode arrays as well as on multiple single emitter platforms will be described. The prospects of power scaling as well as expected limitations to different designs will be discussed. We demonstrate 976 nm pump module with 55W ex-fiber output power from 105 μm core diameter fiber. The coupling efficiency was 58%. Similar approach was used for realization of 1450 nm diodes and as a result over 15 W CW power was achieved from the fiber with the same aperture.