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

European Quantum Electronics Conference (EQEC)

High heralding efficiency single photon source at telecom wavelength

Sabine Wollmann, Morgan M. Weston, Helen M. Chrzanowski, Sergei Slussarenko, Geoff J. Pryde

Published Jun 21, 2015• 1 citation
OpenAlex

Abstract

The generation of high purity single photons and entangled photon pairs is a crucial first step in many quantum optics experiments, including those that require quantum teleportation [1], entanglement swapping [2], and the generation of multi-photon entanglement [3]. The most widely used and established approach for creating photon pairs is spontaneous parametric down conversion (SPDC) - where pump photons undergo a non-linear optical process to create a down-converted photon pair [4]. Traditionally, the generation of high-purity heralded single photons required severe spectral filtering, introducing additional loss. However, through careful engineering of spectral correlations of the down-converted photon pairs one can circumvent the need for filtering and avoid the accompanying reduction in heralding efficiency.

Related papers

Characterization of spectrally filtered heralded single photons

John F. Suárez-Pérez, Alejandra Valencia, Mayerlin Núñez Portela

One method to produce pure heralded single photons (HSP) when using the optical process of spontaneous parametric down-conversion (SPDC) is by modifying the joint spectrum of the photon pairs by means of spectral filters. In this work, we characterize the dependence, with the bandwidth of such filters, of the spectral purity and heralding efficiency of the HSP generated in a bulk SPDC. The values we report for the purity and heralding efficiency are obtained from measurements of the joint spectrum. Our results are in agreement with the theoretical model that predicts a trade-off between the purity and heralding efficiency, and they complement similar measurements that have been done for HSP produced by other types of sources.

Journal of the Optical Society of America B•Mar 3, 2020•2 citations

Independent high-purity photons created in domain-engineered crystals

Francesco Graffitti, Peter Barrow, Massimiliano Proietti +2 more

Advanced photonic quantum technology relies on multi-photon interference which requires bright sources of high-purity single photons. Here, we implement a novel domain-engineering technique for tailoring the nonlinearity of a parametric down-conversion crystal. We create pairs of independently-heralded telecom-wavelength photons and achieve high heralding, brightness and spectral purities without filtering.

arXiv:1712.07140•Optica•Apr 26, 2018•95 citations

Generating Telecom-Band Pure Heralded Single Photons On A Silica Chip

T. Hiemstra, A. Eckstein, Ulrich B. Hoff +9 more

Single photon sources are a key building block for quantum information processing. A common approach uses spontaneous emitters based on parametric down conversion and four wave mixing. In 2005 experiments on the first spectrally engineered four wave mixing sources in fibre were published [1,2]. A primary obstacle for photonics to realize quantum-enhanced applications is loss. Designing single photon sources matched to single mode optical fibres greatly reduces coupling losses [3]. In addition, tailoring the phase matching properties of the sources to generate factorable photon pairs makes strong spectral filtering obsolete and thereby avoids the degradation of photon number correlations due to loss.

Conference on Lasers and Electro-Optics•Jun 21, 2015•1 citation

Limits on the heralding efficiencies and spectral purities of spectrally filtered single photons from photon-pair sources

Evan Meyer-Scott, Nicola Montaut, Johannes Tiedau +4 more

Photon pairs produced by parametric down-conversion or four-wave mixing can interfere with each other in multiport interferometers or carry entanglement between distant nodes for use in entanglement swapping. This requires the photons to be spectrally pure to ensure good interference and have high heralding efficiency to know accurately the number of photons involved and to maintain high rates as the number of photons grows. Spectral filtering is often used to remove noise and define spectral properties. For heralded single photons high purity and heralding efficiency are possible by filtering the heralding arm, but when both photons in typical pair sources are filtered, we show that the heralding efficiency of one or both of the photons is strongly reduced even by ideal spectral filters with 100% transmission in the passband: any improvement in reduced-state spectral purity from filtering comes at the cost of lowered heralding efficiency. We consider the fidelity to a pure, lossless single photon, symmetrize it to include both photons of the pair, and show this quantity is intrinsically limited for sources with spectral correlation. We then provide a framework for this effect for benchmarking common photon-pair sources and present an experiment where we vary the photon filter bandwidths and measure the increase in purity and corresponding reduction in heralding efficiency.

arXiv:1702.05501•Physical Review A•Jun 26, 2017•107 citations

Experimental Engineering of Photonic Quantum Entanglement

Stefanie Barz, G. Cronenberg, Philip John Walther

Entangled photons are a crucial resource for linear optical quantum communication and quantum computation. Besides the remarkable progress of photon state engineering using atomic memories (Kimble (2008); Yuan et al. (2008)) the majority of current experiments is based on the production of photon pairs in the process of spontaneous parametric down-conversion (SPDC), where the entangled photon pair is concluded from post-selection of randomly occurring coincidences. Here we present new insights into the heralded generation of photon states (Barz et al. (2010); Wagenknecht et al. (2010)) that are maximally entangled in polarization (Schrodinger (1935)) with linear optics and standard photon detection from SPDC (Kwiat et al. (1995)). We utilize the down-conversion state corresponding to the generation of three pairs of photons, where the coincident detection of four auxiliary photons unambiguously heralds the successful preparation of the entangled state (Śliwa & Banaszek (2003)). This controlled generation of entangled photon states is a significant step towards the applicability of a linear optics quantum network (Nielsen & Chuang (2000)), in particular for entanglement distribution (Bennett et al. (1996)), entanglement swapping (Kaltenbaek et al. (2009); Pan et al. (1998)), quantum teleportation (Bouwmeester et al. (1997)), quantum cryptography (Bennett & Brassard (1984); Ekert (1991); Jennewein et al. (2000)) and scalable approaches towards photonics-based quantum computing schemes (Browne & Rudolph (2004); Gottesman & Chuang (1999); Knill et al. (2001)).

InTech eBooks•Mar 21, 2012•0 citations

Tuning single-photon sources for telecom multi-photon experiments

Chiara Greganti, Peter Schiansky, Irati Alonso Calafell +3 more

Accidental photon noise and imperfect single-photon purity in spontaneous parametric down-conversion (SPDC) at telecom wavelengths are overcome by exploiting a passive temporal multiplexing scheme and optimizing the spectral properties of the down- converted photons.

Quantum Information and Measurement (QIM)•Jan 1, 2019•1 citation
The generation of high purity single photons and entangled photon pairs is a crucial first step in many quantum optics experiments, including those that require quantum teleportation [1], entanglement swapping [2], and the generation of multi-photon entanglement [3]. The most widely used and established approach for creating photon pairs is spontaneous parametric down conversion (SPDC) - where pump photons undergo a non-linear optical process to create a down-converted photon pair [4]. Traditionally, the generation of high-purity heralded single photons required severe spectral filtering, introducing additional loss. However, through careful engineering of spectral correlations of the down-converted photon pairs one can circumvent the need for filtering and avoid the accompanying reduction in heralding efficiency.
One method to produce pure heralded single photons (HSP) when using the optical process of spontaneous parametric down-conversion (SPDC) is by modifying the joint spectrum of the photon pairs by means of spectral filters. In this work, we characterize the dependence, with the bandwidth of such filters, of the spectral purity and heralding efficiency of the HSP generated in a bulk SPDC. The values we report for the purity and heralding efficiency are obtained from measurements of the joint spectrum. Our results are in agreement with the theoretical model that predicts a trade-off between the purity and heralding efficiency, and they complement similar measurements that have been done for HSP produced by other types of sources.
Single photon sources are a key building block for quantum information processing. A common approach uses spontaneous emitters based on parametric down conversion and four wave mixing. In 2005 experiments on the first spectrally engineered four wave mixing sources in fibre were published [1,2]. A primary obstacle for photonics to realize quantum-enhanced applications is loss. Designing single photon sources matched to single mode optical fibres greatly reduces coupling losses [3]. In addition, tailoring the phase matching properties of the sources to generate factorable photon pairs makes strong spectral filtering obsolete and thereby avoids the degradation of photon number correlations due to loss.
Photon pairs produced by parametric down-conversion or four-wave mixing can interfere with each other in multiport interferometers or carry entanglement between distant nodes for use in entanglement swapping. This requires the photons to be spectrally pure to ensure good interference and have high heralding efficiency to know accurately the number of photons involved and to maintain high rates as the number of photons grows. Spectral filtering is often used to remove noise and define spectral properties. For heralded single photons high purity and heralding efficiency are possible by filtering the heralding arm, but when both photons in typical pair sources are filtered, we show that the heralding efficiency of one or both of the photons is strongly reduced even by ideal spectral filters with 100% transmission in the passband: any improvement in reduced-state spectral purity from filtering comes at the cost of lowered heralding efficiency. We consider the fidelity to a pure, lossless single photon, symmetrize it to include both photons of the pair, and show this quantity is intrinsically limited for sources with spectral correlation. We then provide a framework for this effect for benchmarking common photon-pair sources and present an experiment where we vary the photon filter bandwidths and measure the increase in purity and corresponding reduction in heralding efficiency.
Entangled photons are a crucial resource for linear optical quantum communication and quantum computation. Besides the remarkable progress of photon state engineering using atomic memories (Kimble (2008); Yuan et al. (2008)) the majority of current experiments is based on the production of photon pairs in the process of spontaneous parametric down-conversion (SPDC), where the entangled photon pair is concluded from post-selection of randomly occurring coincidences. Here we present new insights into the heralded generation of photon states (Barz et al. (2010); Wagenknecht et al. (2010)) that are maximally entangled in polarization (Schrodinger (1935)) with linear optics and standard photon detection from SPDC (Kwiat et al. (1995)). We utilize the down-conversion state corresponding to the generation of three pairs of photons, where the coincident detection of four auxiliary photons unambiguously heralds the successful preparation of the entangled state (Śliwa & Banaszek (2003)). This controlled generation of entangled photon states is a significant step towards the applicability of a linear optics quantum network (Nielsen & Chuang (2000)), in particular for entanglement distribution (Bennett et al. (1996)), entanglement swapping (Kaltenbaek et al. (2009); Pan et al. (1998)), quantum teleportation (Bouwmeester et al. (1997)), quantum cryptography (Bennett & Brassard (1984); Ekert (1991); Jennewein et al. (2000)) and scalable approaches towards photonics-based quantum computing schemes (Browne & Rudolph (2004); Gottesman & Chuang (1999); Knill et al. (2001)).