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Updated: May 11, 2026

Construction and Characterization of External Cavity Diode Lasers for Atomic Physics
Published on: April 24, 2014
Influence of external optical feedback on the alpha factor of semiconductor lasers
1School of Electrical, Computer and Telecommunications Engineering, University of Wollongong, Northfields Ave, Wollongong, NSW 2522, Australia. yanguang@uow.edu.au
Abstract:
This Letter presents the results revealing the influence of external optical feedback (EOF) on the alpha factor, or the linewidth enhancement factor, of semiconductor lasers operating on single mode. First, a method is proposed for the measurement of the alpha over a wide range of optical feedback level, which provides an effective way for investigating the dependence of the alpha on laser operating conditions. Second, experimental investigation based on the proposed method is performed on a GaAlAs laser diode with a multiquantum well structure. It is discovered that the alpha value remains approximately constant with increasing injection current, but has a strong dependence on EOF.
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