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Updated: May 11, 2026
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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
Published on: September 5, 2019
Generation of polarization-entangled photon pairs in a Bragg reflection waveguide
A Vallés1, M Hendrych, J Svozilík
1ICFO-Institut de Ci`encies Fot`oniques, Mediterranean Technology Park, Av Carl Friedrich Gauss 3, 08860 Castelldefels, Barcelona, Spain. adam.valles@icfo.es
Optics Express
|May 15, 2013
Summary
We created highly entangled photon pairs using spontaneous parametric down-conversion in a semiconductor waveguide. This breakthrough advances on-chip sources for quantum communication and computing.
Area of Science:
- Quantum optics
- Semiconductor device physics
- Photonics
Background:
- Spontaneous parametric down-conversion (SPDC) is a key process for generating entangled photons.
- Integrated photonic devices offer miniaturization and scalability for quantum technologies.
- Semiconductor waveguides provide a platform for on-chip optical functionalities.
Purpose of the Study:
- To demonstrate efficient, on-chip generation of polarization-entangled photon pairs.
- To utilize AlxGa(1-x)As semiconductor Bragg reflection waveguides for SPDC.
- To operate at the telecommunication wavelength of 1550 nm for compatibility with existing infrastructure.
Main Methods:
- Experimental demonstration of SPDC in an AlxGa(1-x)As semiconductor Bragg reflection waveguide.
- Characterization of photon pair entanglement in the polarization degree of freedom.
- Measurement of photon pair visibility in various polarization bases.
- Testing of a Clauser-Horne-Shimony-Holt (CHSH) Bell-like inequality.
Main Results:
- Achieved highly entangled photon pairs at 1550 nm.
- Observed photon pair polarization entanglement with visibility exceeding 90%.
- Violated a CHSH Bell-like inequality by more than 3 standard deviations.
- Demonstrated the feasibility of using semiconductor waveguides for on-chip entanglement generation.
Conclusions:
- AlxGa(1-x)As semiconductor Bragg reflection waveguides are effective for on-chip SPDC.
- The generated entangled photon pairs meet criteria for quantum information applications.
- This work is a significant step towards practical, integrated sources of entangled photons.
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