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Updated: Jul 31, 2025

A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Spectrally multiplexed Hong-Ou-Mandel interference with weak coherent states
We demonstrate a virtually imaged phased array as a spectral-to-spatial mode-mapper for quantum communication. This setup enables spectrally resolved Hong-Ou-Mandel interference, crucial for quantum repeaters and key distribution.
Area of Science:
- Quantum communication
- Quantum optics
- Photonics
Background:
- Quantum communication systems require efficient methods for manipulating and interfering photons based on their spectral properties.
- Virtually imaged phased arrays (VIPAs) offer a promising platform for spectral-to-spatial mapping.
Purpose of the Study:
- To investigate the suitability of a VIPA as a spectral-to-spatial mode-mapper (SSMM) for quantum communication applications.
- To demonstrate spectrally resolved Hong-Ou-Mandel (HOM) interference using VIPA-based SSMMs.
Main Methods:
- Generating spectral sidebands on an optical carrier.
- Preparing weak coherent states (WCSs) in distinct spectral modes.
- Utilizing a beam splitter, two SSMMs, and single-photon detectors to measure HOM interference.
- Analyzing coincidence detection patterns for matching and unmatched spectral modes.
Main Results:
- Successfully observed the HOM dip in coincidence detection patterns for matching spectral modes.
- Achieved high interference visibilities up to 45% with WCSs.
- Demonstrated significantly reduced visibility for unmatched spectral modes, confirming spectral selectivity.
- Identified the optical arrangement as a candidate for spectrally resolved Bell-state measurements.
Conclusions:
- VIPAs are suitable SSMMs for quantum communication, enabling spectrally resolved HOM interference.
- The demonstrated setup can be adapted for spectrally resolved Bell-state measurements, a key component in quantum key distribution.
- Simulations suggest a trade-off between secret key generation rate and system complexity in spectrally multiplexed quantum communication links.
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