High power diode laser bars are subjected to single pulse step tests carried out up to and beyond their ultimate limits of operation. Laser nearfields and thermal behavior are monitored for pulse widths in the 10 μs-2 ms-range with streak- and thermo-cameras, respectively. The final phase of the tests allows the in situ observation of the catastrophic optical damage (COD) effect. We find perfect agreement between the location of COD signatures observed by transient emission and thermo-camera measurements on the one side, and optical inspection of the degraded bars on the other side. COD thresholds are determined and the observed dependence on the pulse length is qualitatively explained. This approach allows for testing hardness and homogeneity of facet coatings on a bar level with or without consideration of accidental early single-emitter failure effects and thermal crosstalk between the emitters. It helps embanking sudden degradation and provides insight into the mechanisms governing the device emission behavior at ultimate output powers.

Date Published: 8 February 2012
PDF: 6 pages
Proc. SPIE 8241, High-Power Diode Laser Technology and Applications X, 824107 (8 February 2012); doi: 10.1117/12.905126

Published in SPIE Proceedings Vol. 8241:
High-Power Diode Laser Technology and Applications X
Mark S. Zediker, Editor(s)