High performance photon-pair source based on a fiber-coupled periodically poled KTiOPO4 waveguide

Area of Science:

• Quantum Optics
• Integrated Photonics
• Nonlinear Optics

Background:

• Photon-pair generation is crucial for quantum information processing.
• Waveguide-based sources offer miniaturization and stability advantages.
• Efficient and high-visibility sources are needed for practical quantum applications.

Purpose of the Study:

• To demonstrate efficient photon-pair generation at 1316 nm using a novel waveguide.
• To characterize the performance of the integrated waveguide source.
• To achieve high Hong-Ou-Mandel quantum-interference visibility.

Main Methods:

• Fabrication of a Rb-indiffused waveguide in periodically poled KTiOPO4.
• Fiber coupling for efficient light delivery and collection.
• Type-II phase-matching for photon-pair generation at 1316 nm.
• Measurement of pair production rate and Hong-Ou-Mandel interference visibility.

Main Results:

• Efficient generation of photon pairs at 1316 nm.
• Achieved a pair production rate of 2 x 10^7/s/mW in a 1.08-nm bandwidth.
• Demonstrated a Hong-Ou-Mandel quantum-interference visibility of 98.2% (after accidental coincidence subtraction).
• Results agree well with theoretical modeling including waveguide effects.

Conclusions:

• The developed waveguide source is highly efficient for photon-pair generation.
• The achieved visibility is the highest reported for a waveguide-based source.
• This work advances integrated photonics for quantum technologies.