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

Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE

Development of a parametric down-conversion source for two-photon absorption experiments

T. B. Pittman

Published Sep 13, 2007• 2 citations
Publisher

Abstract

We describe a fiber-coupled parametric down-conversion (PDC) source designed for entanglement-enhanced twophoton absorption experiments. The key feature of the source is a narrowband (~1 MHz) UV diode pumping laser which can be tuned to match the energy of the 5S1/2 to 5D5/2 two-photon transition in Rubidium. The weak narrowband pumping beam is delivered to the PDC crystal through a single-mode fiber, which allows the source to be pre-aligned with a much stronger broadband auxiliary pump laser. The motivation for this PDC source lies within the context of Linear Optics Quantum Computing and Quantum Zeno Gates.

DOI
10.1117/12.734444

Related papers

A Parametric Down-Conversion Source for Two-Photon Absorption Experiments

T. B. Pittman, S. M. Hendrickson, J. D. Franson

We describe a Parametric Down-Conversion source based on a low-power (< 1mW), narrowband (<1 MHz) fiber-coupled pump laser. The source is designed for two-photon absorption experiments related to quantum Zeno gates.

International Conference on Quantum Information•Jan 1, 2008•0 citations

Integrated, bright broadband, two-colour parametric down-conversion source

René Pollmann, Franz Roeder, Victor Quiring +4 more

Broadband quantum light is a vital resource for quantum metrology and spectroscopy applications such as quantum optical coherence tomography or entangled two photon absorption. For entangled two photon absorption in particular, very high photon flux combined with high time-frequency entanglement is crucial for observing a signal. So far these conditions could be met by using high power lasers driving degenerate, type 0 bulk-crystal spontaneous parametric down conversion (SPDC) sources. This naturally limits the available wavelength ranges and precludes deterministic splitting of the generated output photons. In this work we demonstrate an integrated two-colour SPDC source utilising a group-velocity matched lithium niobate waveguide, reaching both exceptional brightness 1.52⋅10 6 pairssmWGHz and large bandwidth (7.8 THz FWHM) while pumped with a few mW of continuous wave (CW) laser light. By converting a narrow band pump to broadband pulses the created photon pairs show correlation times of Δ τ ≈ 120 fs while maintaining the narrow bandwidth Δ ω p ≪ 1 MHz of the CW pump light, yielding strong time-frequency entanglement. Furthermore our process can be adapted to a wide range of central wavelengths.

arXiv:2402.17515•Optics Express•May 13, 2024•19 citations

Narrowband photon pairs with independent frequency tuning for quantum light-matter interactions

Vindhiya Prakash, Lorena C. Bianchet, Marc T. Cuairan +3 more

We describe a cavity-enhanced spontaneous parametric down-conversion (CE-SPDC) source for narrowband photon pairs with filters designed such that 97.7% of the correlated photons are in a single mode of 4.3(4) MHz bandwidth. Type-II phase matching, a tuneable-birefringence resonator, MHz-resolution pump tuning, and tuneable Fabry-Perot filters are used to achieve independent signal and idler tuning. We map the CE-SPDC spectrum using difference frequency generation to precisely locate the emission clusters, demonstrate CE-SPDC driven atomic spectroscopy, and measure a contribution from unwanted modes of 7.7%. The generated photon pairs efficiently interact with neutral rubidium, a well-developed system for quantum networking and quantum simulation. The techniques are readily extensible to other material systems.

arXiv:1911.00056•Optics Express•Dec 4, 2019•13 citations

Improved Technologies for a Single Photon Source

Herrera, Michael Bernardo

The efforts of this research have been directed towards improving both the heralding efficiency and heralding rates of a high performance fiber-coupled single photon source based on an ultrafast pulsed beam-like Type-II parametric down conversion (PDC) source. Entangled photons generated from PDC are inherently broadband (many frequencies) and exit the nonlinear crystal at varying angles (different directions). This makes coupling the photons into single-mode fibers, a desirable feature for quantum computing, difficult. In response to these difficulties we have explored applying multi-layered thin film broadband anti-reflection coatings onto the ends of single-mode fibers using the technique of RF Planar Magnetron Sputtering in an effort to increase the coupling efficiency of the beam-like down converted photons. In addition, we have explored theoretically the broadband nature of novel phase matching geometries to increase heralding rates and minimize photon losses. With the ability to tailor coupling fibers to various down conversion sources we hope to increase both the heralding efficiency and heralding rate to levels needed for a broad range of future experiments.

•Jan 1, 2008•0 citations

An Ultra-Broadband, Integrated Mid-Infrared Photon-Pair Source

Franz Roeder, René Pollmann, Abira Gnanavel +6 more

Broadband photon-pairs from a parametric down-conversion (PDC) source are essential for quantum optics experiments in the context of spectroscopy, quantum optical coherence tomography and entangled two-photon absorption [1]–[2]. Entangled two-photon absorption benefits from the ultra-short correlation time of a highly time-frequency entangled photon-pair which increases the absorption cross-section while in spectroscopy, broad spectral coverage in the mid-infrared allows one to enter the regime of life science applications.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 26, 2023•0 citations

On the measurement of two-photon single-mode coupling efficiency in parametric down-conversion photon sources

Stefania Castelletto, Ivo Pietro Degiovanni, Alan L. Migdall +1 more

Photon-based quantum information schemes have increased the need for light sources that produce individual photons, with many such schemes relying on optical parametric down-conversion (PDC). Practical realizations of this technology require that the PDC light be collected into a single spatial mode defined by an optical fibre. We present two possible models to describe single-mode fibres coupling with PDC light fields in a non-collinear configuration, that lead to two different results. These approaches include factors such as crystal length and walk-off, non-collinear phase-matching and transverse pump field distribution. We propose an experimental test to distinguish between the two. The goal is to help clarify open issues, such as how to extend the theory beyond the simplest experimental arrangements and, more importantly, to suggest ways to improve the collection efficiency.

New Journal of Physics•Jul 30, 2004•30 citations
We describe a fiber-coupled parametric down-conversion (PDC) source designed for entanglement-enhanced twophoton absorption experiments. The key feature of the source is a narrowband (~1 MHz) UV diode pumping laser which can be tuned to match the energy of the 5S1/2 to 5D5/2 two-photon transition in Rubidium. The weak narrowband pumping beam is delivered to the PDC crystal through a single-mode fiber, which allows the source to be pre-aligned with a much stronger broadband auxiliary pump laser. The motivation for this PDC source lies within the context of Linear Optics Quantum Computing and Quantum Zeno Gates.
Broadband quantum light is a vital resource for quantum metrology and spectroscopy applications such as quantum optical coherence tomography or entangled two photon absorption. For entangled two photon absorption in particular, very high photon flux combined with high time-frequency entanglement is crucial for observing a signal. So far these conditions could be met by using high power lasers driving degenerate, type 0 bulk-crystal spontaneous parametric down conversion (SPDC) sources. This naturally limits the available wavelength ranges and precludes deterministic splitting of the generated output photons. In this work we demonstrate an integrated two-colour SPDC source utilising a group-velocity matched lithium niobate waveguide, reaching both exceptional brightness 1.52⋅10 6 pairssmWGHz and large bandwidth (7.8 THz FWHM) while pumped with a few mW of continuous wave (CW) laser light. By converting a narrow band pump to broadband pulses the created photon pairs show correlation times of Δ τ ≈ 120 fs while maintaining the narrow bandwidth Δ ω p ≪ 1 MHz of the CW pump light, yielding strong time-frequency entanglement. Furthermore our process can be adapted to a wide range of central wavelengths.
We describe a cavity-enhanced spontaneous parametric down-conversion (CE-SPDC) source for narrowband photon pairs with filters designed such that 97.7% of the correlated photons are in a single mode of 4.3(4) MHz bandwidth. Type-II phase matching, a tuneable-birefringence resonator, MHz-resolution pump tuning, and tuneable Fabry-Perot filters are used to achieve independent signal and idler tuning. We map the CE-SPDC spectrum using difference frequency generation to precisely locate the emission clusters, demonstrate CE-SPDC driven atomic spectroscopy, and measure a contribution from unwanted modes of 7.7%. The generated photon pairs efficiently interact with neutral rubidium, a well-developed system for quantum networking and quantum simulation. The techniques are readily extensible to other material systems.
The efforts of this research have been directed towards improving both the heralding efficiency and heralding rates of a high performance fiber-coupled single photon source based on an ultrafast pulsed beam-like Type-II parametric down conversion (PDC) source. Entangled photons generated from PDC are inherently broadband (many frequencies) and exit the nonlinear crystal at varying angles (different directions). This makes coupling the photons into single-mode fibers, a desirable feature for quantum computing, difficult. In response to these difficulties we have explored applying multi-layered thin film broadband anti-reflection coatings onto the ends of single-mode fibers using the technique of RF Planar Magnetron Sputtering in an effort to increase the coupling efficiency of the beam-like down converted photons. In addition, we have explored theoretically the broadband nature of novel phase matching geometries to increase heralding rates and minimize photon losses. With the ability to tailor coupling fibers to various down conversion sources we hope to increase both the heralding efficiency and heralding rate to levels needed for a broad range of future experiments.
Broadband photon-pairs from a parametric down-conversion (PDC) source are essential for quantum optics experiments in the context of spectroscopy, quantum optical coherence tomography and entangled two-photon absorption [1]–[2]. Entangled two-photon absorption benefits from the ultra-short correlation time of a highly time-frequency entangled photon-pair which increases the absorption cross-section while in spectroscopy, broad spectral coverage in the mid-infrared allows one to enter the regime of life science applications.
Photon-based quantum information schemes have increased the need for light sources that produce individual photons, with many such schemes relying on optical parametric down-conversion (PDC). Practical realizations of this technology require that the PDC light be collected into a single spatial mode defined by an optical fibre. We present two possible models to describe single-mode fibres coupling with PDC light fields in a non-collinear configuration, that lead to two different results. These approaches include factors such as crystal length and walk-off, non-collinear phase-matching and transverse pump field distribution. We propose an experimental test to distinguish between the two. The goal is to help clarify open issues, such as how to extend the theory beyond the simplest experimental arrangements and, more importantly, to suggest ways to improve the collection efficiency.