Generating local oscillator locally in continuous variable quantum key distribution using optical injection phase...

Area of Science:

• Quantum Information Science
• Optical Physics
• Cryptography

Background:

• Continuous-variable quantum key distribution (CV-QKD) requires a stable local oscillator.
• Existing methods for generating local oscillators can introduce significant noise.
• A true local oscillator is crucial for enhancing CV-QKD security and performance.

Purpose of the Study:

• To investigate the feasibility of optical injection locking with phase-locked loop feedback for generating a true local oscillator in CV-QKD.
• To evaluate the noise and imperfections of this novel approach.
• To compare the proposed method with existing CV-QKD schemes.

Main Methods:

• Utilizing optical injection locking with phase-locked loop feedback.
• Evaluating noise and imperfections of the generated local oscillator.
• Calculating secure key rates and achievable distances under collective attack.
• Comparing the proposed scheme against other CV-QKD protocols.

Main Results:

• The proposed optical injection locking method demonstrates significantly lower noise levels compared to other locally generated local oscillator CV-QKD schemes.
• Calculations show promising secure key rates and achievable distances.
• Results align well with experimental data.

Conclusions:

• Optical injection locking with phase-locked loop feedback is a feasible method for generating a true local oscillator for CV-QKD.
• This approach offers reduced noise and enhanced performance over existing schemes.
• The method shows significant promise for practical implementation of CV-QKD.