Share Email Print
cover

Proceedings Paper

Longitudinally resolved measurements of carrier concentration and gain in 980-nm InGaAs/GaAs high-power quantum well lasers
Author(s): Andrew J. Bennett; Edward H. Sargent; Rick D. Clayton; H. B. Kim; Jing Ming Xu
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

Measurements of longitudinal variation in critical laser parameters such as gain and carrier concentration are invaluable in understanding and diagnosing device performance and failure mechanisms. However, traditional front-facet measurements cannot reveal the variation of these parameters along the length of the laser. Other methods require physical modifications to the laser itself, such as the fabrication of a top window, and are thus invasive. We describe a new experimental technique based on analysis of side spontaneous emission. A tapered optical fiber translated along the side of the laser using a micropositioner collects spontaneous emission from the active region, allowing spatially-resolved gain and carrier concentration measurements to be made. Such measurements can be used to track the evolution of dark lines caused by defects where non-radiative recombination is dominant. We applied this method to a 980 nm high power laser with an In0.2Ga0.8As, 80 angstroms SQW and facets of 90%/10% reflectivity. It was predicted through a 1D rate equation model that the carrier concentration would increase near the high-reflectivity mirror, due to lower optical field intensities. Using the bimolecular recombination equation to determine the carrier density, this expectation was confirmed. The peak modal gain also increased with proximity to the high-reflectivity mirror, and modulations in the gain peak profile attributed to spatial hole burning were observed.

Paper Details

Date Published: 1 May 1997
PDF: 10 pages
Proc. SPIE 3004, Fabrication, Testing, and Reliability of Semiconductor Lasers II, (1 May 1997); doi: 10.1117/12.273830
Show Author Affiliations
Andrew J. Bennett, Univ. of Toronto (Canada)
Edward H. Sargent, Univ. of Toronto (Canada)
Rick D. Clayton, Nortel Technology (Canada)
H. B. Kim, Nortel Technology (Canada)
Jing Ming Xu, Univ. of Toronto (United States)


Published in SPIE Proceedings Vol. 3004:
Fabrication, Testing, and Reliability of Semiconductor Lasers II
Mahmoud Fallahi; S. C. Wang, Editor(s)

© SPIE. Terms of Use
Back to Top