Near perfect mode overlap between independently seeded, gain-switched lasers

Area of Science:

• Quantum Optics
• Laser Physics
• Quantum Information Science

Background:

• Independently seeded, gain-switched laser diodes are crucial for high-repetition-rate applications.
• Achieving high mode overlap and indistinguishability between such laser sources is challenging.

Purpose of the Study:

• To drastically improve mode overlap between independently seeded, gain-switched laser diodes.
• To generate high-rate, indistinguishable coherent pulses for quantum information applications.

Main Methods:

• Implementation of a pulsed light seeding technique for laser diodes.
• Measurement of interference in both macroscopic and single-photon regimes.
• Utilizing Monte Carlo simulations for result validation.

Main Results:

• Demonstrated near-perfect mode overlap in the macroscopic regime.
• Achieved a Hong-Ou-Mandel dip visibility of 0.499 ± 0.004 in the single-photon regime, saturating the theoretical limit.
• Reduced emission time jitter and enabled frequency chirp synchronization.

Conclusions:

• The pulsed light seeding technique significantly enhances mode overlap and pulse indistinguishability.
• The developed light source is ideal for generating high-rate, indistinguishable coherent pulses.
• This advancement is critical for the progress of quantum information applications.