We report a study of the gain characteristics of a self-organized InAs/GaAs quantum-dot laser. Using the Hakki–Paoli technique, we are able to determine the spectral form of the modal gain, its dependence upon current, and the differential gain. A quasiperiodic modulation of the below-threshold gain is observed. This modulation is shown to be responsible for the form of the lasing spectra, which consist of groups of lasing modes separated by nonlasing spectral regions. Possible mechanisms for this behavior are discussed.

Topics
Amplifiers, Self assembly, Lasers
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© 1999 American Institute of Physics.
1999
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