Stack designs for high brightness, highly reliable QCW pump sources

Abstract

Recent developments in both stacking technology and diode design have led to highly reliable pump sources with power densities in excess of 5kW/cm2. For most applications a collimation of the fast axis is required. Proper bar alignment and control of bar smile allow collimation down to a bar to bar pitch of 400µm. Furthermore the available power density has been increased by the advent of bars with peak power of up to 500W per bar. At 940nm these stacks operate at very low currents of only ∼200A for 500W/bar. This low drive current strongly simplifies the power supply of the huge systems.