Multi-mode optical fiber

Photon entanglement

Quantum entanglement

Physics

Nonlinear system

Optics

Quantum network

Photon

Optical fiber

Photonics

Quantum mechanics

Optoelectronics

Quantum optics

Quantum

Soliton

Quantum sensor

Nature Photonics

Soliton microcombs—phase-locked microcavity frequency combs—have become the foundation of several classical technologies in integrated photonics, including spectroscopy, LiDAR and optical computing. Despite the predicted multimode entanglement across the comb, experimental study of the quantum optics of the soliton microcomb has been elusive. In this work we use second-order photon correlations to study the underlying quantum processes of soliton microcombs in an integrated silicon carbide microresonator. We show that a stable temporal lattice of solitons can isolate a multimode below-threshold Gaussian state from any admixture of coherent light, and predict that all-to-all entanglement can be realized for the state. Our work opens a pathway toward a soliton-based multimode quantum resource. The quantum aspect of soliton microcomb from an integrated silicon carbide microresonator is studied in several regimes — below threshold, above threshold and in the soliton regime — using a single-photon optical spectrum analyser for second-order photon correlation measurement.

Quantum optics of soliton microcombs