Excitability in optically injected semiconductor lasers: contrasting quantum-well- and quantum-dot-based devices

Area of Science:

• Semiconductor laser physics
• Optoelectronics
• Quantum optics

Background:

• Optically injected semiconductor lasers are predicted to exhibit excitability.
• The specific dynamics of excitability differ significantly across various semiconductor laser types.
• Understanding these differences is crucial for laser design and application.

Purpose of the Study:

• To investigate and contrast the excitability dynamics in quantum-well (QW) lasers and quantum-dot (QD) lasers.
• To identify the underlying physical mechanisms responsible for the observed differences in pulse dynamics.
• To elucidate the role of device stability in shaping excitability phenomena.

Main Methods:

• Experimental observation of pulse shapes in optically injected QW and QD lasers.
• Theoretical modeling and analysis of laser dynamics.
• Comparative study of stability against perturbations.

Main Results:

• Quantum-well lasers exhibit complex, multipulse trajectories under optical injection.
• Quantum-dot lasers display significantly simpler excitability dynamics.
• Experimental pulse shapes clearly reflect these distinct behaviors.

Conclusions:

• The increased stability of quantum-dot lasers to perturbations is the root cause for their simpler excitability dynamics.
• This finding highlights the importance of material and structural properties in determining laser behavior.
• The results offer insights for tailoring semiconductor lasers for specific applications.