Visible-Telecom Entangled-Photon Pair Generation with Integrated Photonics: Guidelines and a Materials Comparison

Area of Science:

• Quantum optics and integrated photonics.

Background:

• Correlated photon-pair sources are essential for quantum computing, networking, synchronization, and sensing.
• Integrated photonics offers chip-scale sources for high-rate entanglement at telecom wavelengths.
• Visible-telecom entangled-pair sources are needed to connect remote quantum systems.

Purpose of the Study:

• To evaluate biphoton pair generation and time-energy entanglement in various nonlinear integrated photonic materials.
• To demonstrate geometric dispersion engineering for phase-matching across different platforms.
• To identify robust designs and novel phase-matching conditions for expanded operational ranges.

Main Methods:

• Spontaneous four-wave mixing in silicon nitride, lithium niobate, aluminum gallium arsenide, indium gallium phosphide, and gallium nitride.
• Geometric dispersion engineering for phase-matching optimization.
• Analysis of fabrication tolerance and phase-matching conditions.

Main Results:

• Successful biphoton generation and time-energy entanglement demonstrated across multiple material platforms.
• Geometric dispersion engineering effectively achieved phase-matching for each material.
• Identified robust designs insensitive to fabrication variations.
• Discovered a Type-1 cross-polarized phase-matching condition in III-V materials, extending wavelength applicability.

Conclusions:

• Integrated nonlinear photonics platforms can be engineered for efficient visible-telecom entangled photon-pair generation.
• Dispersion engineering is crucial for tailoring phase-matching conditions in diverse materials.
• The findings pave the way for advanced quantum communication and sensing networks using chip-scale sources.