Engineering spectrally unentangled photon pairs from nonlinear microring resonators by pump manipulation

Area of Science:

• Integrated quantum photonics
• Quantum information science
• Nonlinear optics

Background:

• Quantum photonics requires precise preparation of quantum states.
• Quantum-correlated photon pairs are crucial for quantum protocols.
• Spontaneous nonlinear processes in microring resonators are used for photon pair generation.

Purpose of the Study:

• To propose a novel method for generating spectrally unentangled photon pairs.
• To achieve on-chip generation of heralded single photons with high purity.
• To overcome limitations of spectral filtering in current methods.

Main Methods:

• Utilizing interference between primary and delayed secondary pump pulses.
• Increasing the effective pump spectral width within a microring resonator.
• Generating heralded single photons from a standard microring resonator structure.

Main Results:

• Achieved on-chip generation of spectrally unentangled photon pairs.
• Produced heralded single photons with state purities exceeding 99%.
• Demonstrated the effectiveness of the method without requiring spectral filtering.

Conclusions:

• The proposed method offers a refined approach for quantum state preparation in integrated photonics.
• High-purity heralded single photons can be generated efficiently on-chip.
• This technique advances the development of quantum protocols relying on integrated quantum photonics.