Kerr nonlinearity, self-injection locking and correlation in a microresonator.

Area of Science:

• Quantum Optics
• Integrated Quantum Technologies
• Nonlinear Optics

Background:

• Entangled photon pair production is crucial for quantum communication, computing, and physics.
• Efficient generation and spatial separation of entangled photons are key challenges in integrated quantum technologies.
• Parametric oscillators are vital for generating photon pairs, but low-loss methods are needed.

Purpose of the Study:

• To demonstrate nonlinear generation of correlated optical harmonics.
• To address the challenge of spatial separation of generated photons while preserving entanglement.
• To advance integrated quantum technologies through efficient photon pair generation.

Main Methods:

• Utilized non-degenerate four-wave mixing in an optimally pumped optical microcavity with Kerr nonlinearity.
• Achieved phase matching using self-injection locked lasers locked to two different microresonator modes.
• Employed counterpropagating light from two self-injection locked lasers for spatial separation.

Main Results:

• Demonstrated nonlinear generation of correlated optical harmonics.
• Successfully addressed the spatial separation challenge for generated harmonics.
• Showcased correlation mediated by self-injection locking and Kerr nonlinearity between lasers.
• Validated theoretical predictions using integrated semiconductor lasers and a whispering gallery mode resonator.

Conclusions:

• The demonstrated method offers an efficient approach for generating entangled photon pairs.
• The technique effectively overcomes spatial separation issues in integrated quantum systems.
• This work contributes to the advancement of integrated quantum technologies.