Consistency properties of a chaotic semiconductor laser driven by optical feedback

Area of Science:

• Nonlinear dynamics
• Semiconductor laser physics
• Optical feedback systems

Background:

• Semiconductor lasers are crucial in optical communications.
• Understanding their dynamic behavior under optical feedback is essential.
• Chaos and consistency properties are key characteristics of laser dynamics.

Purpose of the Study:

• To experimentally investigate the consistency properties of a semiconductor laser.
• To analyze laser responses to coherent optical drive with delayed feedback.
• To relate consistency properties to strong and weak chaos regimes.

Main Methods:

• Experimental setup involving a semiconductor laser with selectable short and long optical fiber loops.
• Application of a coherent optical drive with controlled delayed feedback.
• Repetitive application of the same optical drive to observe response consistency.
• Analysis of laser output to distinguish between consistent and inconsistent responses.

Main Results:

• Observed that the semiconductor laser exhibits consistent or inconsistent responses to identical optical drive inputs.
• Demonstrated a dependence of response consistency on the pump parameter.
• Correlated consistent responses with weak chaos and inconsistent responses with strong chaos.
• Experimentally determined the sub-Lyapunov exponent governing these consistency properties.

Conclusions:

• The study provides experimental evidence for distinct consistency properties in semiconductor lasers under delayed optical feedback.
• The findings link laser response consistency to the underlying chaotic dynamics (strong vs. weak chaos).
• The experimental determination of the sub-Lyapunov exponent offers a quantitative measure for understanding laser stability and predictability.