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Updated: Dec 6, 2025
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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
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Demonstration of a polarization-entangled photon-pair source based on phase-modulated PPLN
Paulina S Kuo1, Varun B Verma2, Sae Woo Nam2
1Information Technology Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, USA.
OSA Continuum
|October 8, 2020
Summary
Researchers created a new source for polarization-entangled photon pairs using engineered crystals. This breakthrough achieves high visibility for quantum entanglement at telecom wavelengths.
Area of Science:
- Quantum optics
- Nonlinear optics
- Materials science
Background:
- Spontaneous parametric down-conversion (SPDC) is a key process for generating entangled photon pairs.
- Periodically poled lithium niobate (PPLN) is widely used for SPDC, but achieving specific entanglement properties can be challenging.
- Birefringence in nonlinear crystals leads to different phase-matching conditions for different polarization states.
Purpose of the Study:
- To develop and demonstrate a novel source of polarization-entangled photon pairs.
- To achieve high-visibility entanglement at telecom wavelengths using domain-engineered PPLN.
- To investigate the performance of phase-modulated aperiodic structures for SPDC.
Main Methods:
- Utilized domain-engineered, periodically poled lithium niobate (PPLN) for type-II SPDC.
- Employed phase-modulation of the domain structure to create an aperiodically poled crystal.
- Pumped the source at 775 nm to generate non-degenerate photon pairs at telecom wavelengths (1530 nm and 1569 nm).
- Compared the performance of the phase-modulated crystal with other aperiodic structures.
Main Results:
- Successfully generated polarization-entangled photon pairs with high visibility (>93%).
- Demonstrated simultaneous generation of different polarization-entangled states within a single crystal.
- Observed non-degenerate signal and idler pairs at telecom wavelengths.
Conclusions:
- The developed domain-engineered PPLN source is effective for generating high-visibility polarization-entangled photon pairs.
- Phase-modulated aperiodic structures offer a promising approach for advanced quantum light sources.
- This work advances the development of practical quantum communication and computation technologies.
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