Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Quantum 2.0 Conference and Exhibition

Joint Spectral Characterization of Photon Pairs Generated in (Al)GaAs-on-insulator Waveguides

Alexandre Z. Leger, Emil Zanchetta Ulsig, Eric J. Stanton, Dileep V. Reddy, Nicolas Volet, Lynden K. Shalm, Martin J. Stevens, Deny R. Hamel, Richard P. Mirin

Published Jan 1, 2024• 0 citations
Publisher

Abstract

We demonstrate spontaneous parametric downconversion in straight GaAs and AlGaAs-on-insulator waveguides, which yield a maximum pair generation rate of 1.2 × 1010s−1mW−1, normalized to the pump power. The joint spectral intensity is directly measured via time-of-flight spectroscopy.
DOI
10.1364/quantum.2024.qw3a.31

Related papers

Joint spectral characterization of SPDC photon pairs near 2 $μ$m in (Al)GaAs-on-insulator waveguides

Alexandre Z. Leger, Emil Z. Ulsig, Samuel E. Fontaine +8 more

Integrated photon-pair sources are a core component of chip-based quantum computing, communication, and metrology. Although such sources have been demonstrated at conventional telecom wavelengths, the 2 $μ$m band remains comparatively less explored, despite offering advantages for free-space quantum communication, low-loss transmission in emerging fiber networks, and integration with silicon photonic platforms. In this paper, we demonstrate spontaneous parametric down-conversion (SPDC) in straight GaAs- and AlGaAs-on-insulator waveguides. This platform offers strong second-order nonlinearity and geometry-tunable dispersion, which are advantageous for efficient on-chip pair generation. Measurements of the joint spectral intensity and heralded second-order correlation function show broadband emission around 2 $μ$m with strong spectral anti-correlations. To our knowledge, this is the first direct joint-spectral characterization of an integrated SPDC source in this wavelength regime.

physics.opticsCross-listedarXiv:2608.03950•Aug 5, 2026•0 citations

Measurement of the spectral properties of the two-photon state generated via type II spontaneous parametric downconversion

Yoon-Ho Kim, Warren P. Grice

We report complete measurement of the spectral properties of photon pairs generated via spontaneous parametric downconversion. The measurements, which include not only single-photon spectra but also two-photon joint spectra, were performed for both cw and ultrafast-pumping configurations. In agreement with theoretical predictions, the spectra for the ultrafast-pumped case reveal asymmetries that are not present with cw pumping.

Optics Letters•Apr 15, 2005•121 citations

Spectral characterization of biphotons using quantum interferometric spectroscopy

Samuel Corona-Aquino, Zi-Qi Zeng, Tao Xie +11 more

The spectral distribution of photon pairs produced by spontaneous parametric downconversion (SPDC) is one of the most exploited degrees of freedom in multiphoton experiments. Consequently, the characterization of such correlations is, without a doubt, a task of utmost importance. Common methods for measuring the joint spectral intensity (JSI) of correlated photon pairs often exhibit several drawbacks, such as the requirement for a bright source to offset high losses or the need for two-dimensional measurements, which can lead to prolonged acquisition times. In this work, we experimentally demonstrate a technique that allows for the reconstruction of the JSI from a single interferometric measurement, thus reducing the dimensionality of the problem. The reconstructed JSIs show good agreement with those obtained directly through a fiber spectrometer, confirming the effectiveness of our approach. This technique significantly enhances the efficiency of JSI characterization, offering a resource-efficient method for quantum state characterization in SPDC-based experiments.

APL Photonics•Jun 1, 2025•0 citations

Bragg reflection waveguides as a source of photon pairs: theory and experiments

Jiŕí Svozilík, Adam Vallés, Martin Hendrych +1 more

In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching the phasematching of spontaneous parametric downconversion process in semiconductor materials. We have designed two different waveguide structures. The first one is based on AlGaN and it is able to produce spectrally uncorrelated photon pairs. The second one is based on AlGaAs and it allows us to generate entangled photon pairs with ultra-broad spectra. Spontaneous-parametric-downconversion and second-harmonic-generation experiments are presented.

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE•Apr 30, 2011•1 citation

Modal-entangled photons pairs in a ppLN ridge waveguide

Ramesh Kumar, Joyee Ghosh

We studied the joint spectral intensity (JSI) of modal-entangled photons pairs generated through spontaneous parametric down conversion (SPDC) using a spatial Hermite-Gaussian HG(1,0) pulsed pump beam in a periodically-poled lithium niobate (ppLN) ridge waveguide.

OSA Quantum 2.0 Conference•Jan 1, 2020•1 citation

Spectral properties of entangled-photons generated via type-I spontaneous parametric downconversion

So-Young Baek, Yoon-Ho Kim

Complete measurement of single-photon and two-photon joint spectral properties of entangled photon pairs generated via type-I spontaneous parametric down-conversion under different phase- matching conditions are reported. A theoretical model is also developed to explain the observed two- photon joint spectra.

Conference on Lasers and Electro-Optics•May 1, 2007•1 citation
Joint spectral characterization of SPDC photon pairs near 2 μμμm in (Al)GaAs-on-insulator waveguides
Integrated photon-pair sources are a core component of chip-based quantum computing, communication, and metrology. Although such sources have been demonstrated at conventional telecom wavelengths, the 2 μμμm band remains comparatively less explored, despite offering advantages for free-space quantum communication, low-loss transmission in emerging fiber networks, and integration with silicon photonic platforms. In this paper, we demonstrate spontaneous parametric down-conversion (SPDC) in straight GaAs- and AlGaAs-on-insulator waveguides. This platform offers strong second-order nonlinearity and geometry-tunable dispersion, which are advantageous for efficient on-chip pair generation. Measurements of the joint spectral intensity and heralded second-order correlation function show broadband emission around 2 μμμm with strong spectral anti-correlations. To our knowledge, this is the first direct joint-spectral characterization of an integrated SPDC source in this wavelength regime.
The spectral distribution of photon pairs produced by spontaneous parametric downconversion (SPDC) is one of the most exploited degrees of freedom in multiphoton experiments. Consequently, the characterization of such correlations is, without a doubt, a task of utmost importance. Common methods for measuring the joint spectral intensity (JSI) of correlated photon pairs often exhibit several drawbacks, such as the requirement for a bright source to offset high losses or the need for two-dimensional measurements, which can lead to prolonged acquisition times. In this work, we experimentally demonstrate a technique that allows for the reconstruction of the JSI from a single interferometric measurement, thus reducing the dimensionality of the problem. The reconstructed JSIs show good agreement with those obtained directly through a fiber spectrometer, confirming the effectiveness of our approach. This technique significantly enhances the efficiency of JSI characterization, offering a resource-efficient method for quantum state characterization in SPDC-based experiments.
In this paper, we present Bragg reflection waveguides as a novel universal platform for reaching the phasematching of spontaneous parametric downconversion process in semiconductor materials. We have designed two different waveguide structures. The first one is based on AlGaN and it is able to produce spectrally uncorrelated photon pairs. The second one is based on AlGaAs and it allows us to generate entangled photon pairs with ultra-broad spectra. Spontaneous-parametric-downconversion and second-harmonic-generation experiments are presented.