Intermittent microwave bursts of a semiconductor laser with an ultra-long loop for generating timing-based random...

Area of Science:

• Physics
• Nonlinear Dynamics
• Optoelectronics

Background:

• Chaotic dynamics in semiconductor lasers are crucial for random bit generation (RBG).
• Optical feedback introduces complex dynamics, including intermittent bursts, in laser emission.
• Ultra-long feedback loops can enhance chaotic behavior and enable novel applications.

Purpose of the Study:

• To demonstrate a fast, timing-based random bit generation (RBG) method.
• To explore chaotic dynamics of a single-mode semiconductor laser with an ultra-long feedback loop.
• To analyze the characteristics of intermittent microwave bursts for randomness extraction.

Main Methods:

• Utilizing a single-mode semiconductor laser with a 5-km fiber optical feedback loop.
• Analyzing the emission intensity for intermittent microwave bursts at relaxation resonance frequencies.
• Extracting randomness from the irregular timing of these microwave bursts.

Main Results:

• Observed intermittent microwave bursts (7 GHz) within each round trip of the feedback loop.
• Demonstrated a high-speed RBG rate of 9.6 Gbps.
• Confirmed that the timing variations in the burst envelopes are a source of randomness.

Conclusions:

• A novel, high-speed timing-based RBG method is demonstrated using chaotic semiconductor laser dynamics.
• Intermittent microwave bursts generated by ultra-long optical feedback are a viable mechanism for fast random bit generation.
• The nonlinear dynamics within the feedback loop effectively store randomness for RBG applications.