Excitability in a quantum dot semiconductor laser with optical injection

Area of Science:

• Optics and Photonics
• Semiconductor Physics
• Nonlinear Dynamics

Background:

• Quantum dot semiconductor lasers are crucial for modern optoelectronics.
• Understanding their dynamic behavior under external stimuli like optical injection is essential for device performance.
• Previous studies have explored various nonlinear phenomena in semiconductor lasers.

Purpose of the Study:

• To experimentally investigate the dynamic behavior of a quantum dot semiconductor laser under optical injection.
• To identify and characterize novel pulse excitability phenomena.
• To theoretically explain the observed dynamics using bifurcation theory.

Main Methods:

• Experimental setup involving a quantum dot semiconductor laser subjected to optical injection.
• Observation and analysis of laser output dynamics.
• Theoretical modeling using concepts of saddle-node and period-doubling bifurcations.

Main Results:

• Observed single- and double-pulse excitability at the boundary of the locking region.
• Identified these pulses as manifestations of saddle-node bifurcation on a limit cycle.
• Linked double pulses to period-doubling bifurcations on the same homoclinic curve as single pulses.

Conclusions:

• The study reveals complex nonlinear dynamics in quantum dot lasers under optical injection.
• Saddle-node and period-doubling bifurcations are key mechanisms governing observed pulse excitability.
• The findings contribute to a deeper understanding of laser dynamics and potential applications.