Random number generation by coherent detection of quantum phase noise

Area of Science:

• Quantum optics
• Laser physics
• Information security

Background:

• Previous random number generators based on laser phase drift had limitations like requiring long interferometers or active stabilization.
• These methods often necessitated randomness extraction to achieve uniform probability distributions.

Purpose of the Study:

• To demonstrate a new quantum random number generator that overcomes the limitations of previous laser-based schemes.
• To achieve intrinsically uniform random number generation using readily available telecom equipment.

Main Methods:

• Utilizing the random phase difference between two independent laser sources.
• Employing two coherent detectors for phase measurement.
• Leveraging telecom equipment for phase measurement.

Main Results:

• Demonstrated a quantum random number generator with intrinsically uniform probability distribution, eliminating the need for randomness extraction.
• Achieved random bit generation speeds dependent on photodetector bandwidth and laser linewidth.
• Obtained visual representations of laser phase noise development over time.

Conclusions:

• The proposed method provides a more practical and efficient approach to quantum random number generation.
• The system's reliance on standard telecom equipment simplifies implementation.
• The visual byproduct offers a novel method for measuring laser coherence time.