As diode pumped solid state lasers gain more market share, the performance, stability and lifetime of the diode pump source faces unprecedented scrutiny. Lifetimes of diode pumps in excess of 35,000 hrs are sought with no intervention or maintenance from the end user. One lifetime and power limiting phenomena for arrays is that of solder creep typical with traditional mounting using soft solders such as Indium. Harder solders such as Gold/Tin on Copper-Tungsten submounts provide a more robust and stable mounting system for long term high power pump sources. Furthermore, beam multiplexing of laser bars require tight wavelength and polarization purity which are affected by mounting induced strain. In this investigation, high power 940 nm laser bars, operating in the 100 to 200 W power range, were mounted using AuSn/CuW and In soldering schemes. The differences in thermal and strain characteristics are investigated through the examination of the emitter wavelength, nearfield measurements, polarization and smile. The measurements are correlated with finite element modeling to predict the 3-dimensional thermal distributions within the laser bars.

Date Published: 6 February 2007
PDF: 12 pages
Proc. SPIE 6456, High-Power Diode Laser Technology and Applications V, 645602 (6 February 2007); doi: 10.1117/12.702022

Published in SPIE Proceedings Vol. 6456:
High-Power Diode Laser Technology and Applications V
Mark S. Zediker, Editor(s)