Frequency-Domain Quantum Interference with Correlated Photons from an Integrated Microresonator

Area of Science:

• Quantum optics
• Integrated photonics
• Quantum information science

Background:

• All-photonic quantum networks require efficient methods for processing quantum information.
• Frequency encoding offers a promising approach to reduce complexity and resource needs.
• Coherent, selective interactions between spectrally distinct photons are crucial but challenging.

Purpose of the Study:

• To demonstrate frequency-domain Hong-Ou-Mandel interference using chip-based photon sources.
• To establish a method for selective, high-fidelity two-photon operations in the frequency domain.
• To provide a building block for frequency-multiplexed photonic quantum networks.

Main Methods:

• Generation of spectrally distinct photons from a chip-based microresonator.
• Implementation of an active
• frequency beam splitter
• using four-wave mixing.
• Observation of Hong-Ou-Mandel interference between photons of different frequencies.

Main Results:

• Achieved high interference visibilities of 0.95±0.02 in the frequency domain.
• Demonstrated the efficacy of four-wave mixing for selective two-photon operations.
• Successfully generated and interfered spectrally distinct photons from an integrated source.

Conclusions:

• Four-wave mixing is a viable tool for high-fidelity frequency-domain quantum operations.
• Integrated photonics and frequency encoding are key for scalable quantum networks.
• This work advances the development of frequency-multiplexed photonic quantum networks.