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

arXiv:2506.01661

Efficient fiber coupling of telecom single-photons from circular Bragg gratings

Tran, Nam, Pavel Ruchka, Sara Jakovljevic, Benjamin Breiholz, Peter Gierß, Ponraj Vijayan, Carlos Jimenez, Alois Herkommer, Michael Jetter, Simone Luca Portalupi, Harald W. Giessen, Peter Michler

Published Jun 2, 2025• 0 citations
arXivHTMLPDF

Abstract

Deterministic sources of quantum light are becoming increasingly relevant in the development of quantum communication, particularly in deployed fiber networks. Therefore, efficient fiber-coupled sources at telecom wavelength are highly sought after. With this goal in mind, we systematically investigate the fiber coupling performance of quantum dots in optical resonators under three experimental configurations. We quantify coupling efficiency and sensitivity to spatial displacement for single-mode fibers with 3D printed optics on their tip, and benchmark their behavior over a commercial cleaved-cut fiber and a standard optical setup. The reduction of the required optical elements when operating with a lensed or a bare fiber allows for an increased end-to-end efficiency by a factor of up to 3.0 +/- 0.2 over a standard setup. For the perspective of realizing a mechanically stable fiber-coupled source, we precisely quantify the spatial tolerance to fiber-cavity misalignment, observing less than 50 % count rate drop for several micrometers displacement. These results will play a key role in the future development of fiber-coupled sources of quantum light.

DOI
10.48550/arxiv.2506.01661

Related papers

Collecting Telecom Photons From Circular Bragg Gratings Using Optical Fibers and 3D Printed Micro‐Lenses

Nam Tran, Pavel Ruchka, Sara Jakovljevic +9 more

Abstract Deterministic sources of quantum light are becoming increasingly relevant in the development of quantum communication, particularly in deployed fiber networks. Therefore, efficient fiber‐coupled sources at telecom wavelength are highly sought after. With this goal in mind, the fiber coupling performance of quantum dots is systematically investigated in optical resonators under three experimental configurations. For the first time coupling efficiency and sensitivity are quantified to spatial displacement for single‐mode fibers with 3D printed optics on their tip, and benchmark their behavior over a commercial cleaved‐cut fiber and a standard optical setup. The reduction of the required optical elements when operating with a lensed or a bare fiber allows for an increased end‐to‐end efficiency over a standard setup. For the perspective of realizing a mechanically stable fiber‐coupled source, the spatial tolerance is precisely quantified to fiber‐cavity misalignment, observing less than count rate drop for several micrometers displacement. In the spirit of precise quantification and reproducibility, the experiments are performed on multiple photonic resonators. These results will play a key role in the future development of fiber‐coupled sources of quantum light.

Advanced Quantum Technologies•Sep 19, 2025•2 citations

Optimized designs for telecom-wavelength quantum light sources based on hybrid circular Bragg gratings

Lucas Rickert, Timm Kupko, Sven Rodt +2 more

We present a design study of quantum light sources based on hybrid circular Bragg gratings (CBGs) for emission wavelengths in the telecom O-band. The evaluated CBG designs show photon extraction efficiencies > 95% and Purcell factors close to 30. Using simulations based on the finite element method, and considering the influence of possible fabrication imperfections, we identify optimized high-performance CBG designs which are robust against structural aberrations. In particular, full 3D simulations reveal that the designs show robustness regarding lateral deviations of the emitter position in the device well within reported positioning accuracies of deterministic fabrication technologies. Furthermore, we investigate the coupling of the evaluated hybrid CBG designs to single-mode optical fibers, which is particularly interesting for the development of practical quantum light sources. We obtain coupling efficiencies of up to 77% for off-the-shelf fibers, and again proof robustness against fabrication imperfections. Our results show prospects for the fabrication of close-to-ideal fiber-coupled quantum light sources for long distance quantum communication.

arXiv:1908.08408•Optics Express•Dec 4, 2019•83 citations

Rack-integrated quantum dot-based source of single and entangled photons at telecom C-band

Michal Vyvlecka, Raphael Joos, Benjamin Breiholz +8 more

For quantum light sources in everyday telecommunication networks, quantum science needs to be fully transformed into quantum technology. The first necessary step to move outside a well-controlled lab environment requires the use of quantum light sources operating in the technologically relevant telecom O- and C-band. This can be provided using epitaxial quantum dots as deterministic sources of quantum light. Particularly intriguing is that emitters operating at telecom wavelengths are rapidly catching up with their short wavelength counterparts in terms of performances. Here, we make a decisive step forward in the development of quantum communication networks: a state-of-the-art source of quantum light, a semiconductor quantum dot (QD), with record coincidence rate for entangled photon emission in the telecom C-band, is operated inside an optimized rack-based setup. This setup includes a tunable pulsed laser for the QD excitation (from quasi- to fully resonant excitation), all optics for the excitation filtering, and QD signal coupling into single-mode fibers. Overall, the setup allows for above $50\%$ transmission for both exciton and biexciton photons. These results show that quantum dots-based telecom light sources can now be transported and integrated into existing fiber infrastructures, an important step to demonstrate the feasibility of the upcoming quantum internet.

quant-pharXiv:2607.21454•Jul 24, 2026•0 citations

Bright single-photon sources in the telecom band by deterministically coupling single quantum dots to a hybrid circular Bragg resonator

Shi-Wen Xu, Yuming Wei, Rongbin Su +7 more

High-performance solid-state quantum sources in the telecom band are of paramount importance for long-distance quantum communications and the quantum Internet by taking advantage of a low-loss optical fiber network. Here, we demonstrate bright telecom-wavelength single-photon sources based on In(Ga)As/GaAs quantum dots (QDs) deterministically coupled to hybrid circular Bragg resonators (h-CBRs) by using a wide-field fluorescence imaging technique. The QD emissions are redshifted toward the telecom O-band by using an ultra-low InAs growth rate and an InGaAs strain reducing layer. Single-photon emissions under both continuous wave (CW) and pulsed operations are demonstrated, showing high brightness with count rates of 1.14 MHz and 0.34 MHz under saturation powers and single-photon purities of g ( 2 ) ( 0 ) = 0.11 ± 0.02 (CW) and g ( 2 ) ( 0 ) = 0.087 ± 0.003 (pulsed) at low excitation powers. A Purcell factor of 4.2 with a collection efficiency of 11.2 % ± 1 % at the first lens is extracted, suggesting efficient coupling between the QD and h-CBR. Our work contributes to the development of highly efficient single-photon sources in the telecom band for fiber-based quantum communication and future distributed quantum networks.

Photonics Research•Jun 6, 2022•30 citations

Bright Purcell enhanced single-photon source in the telecom O-band based on a quantum dot in a circular Bragg grating

Sascha Kolatschek, Stephanie Bauer, Cornelius Nawrath +6 more

In the field of quantum communication and quantum cryptography, the need for bright non-classical light sources remains a key requirement. Semiconductor quantum dots (QDs) have proven to be excellent candidates also being able to emit single-photons in the much sought after telecom bands. To overcome the high refractive index contrast between the semiconductor matrix and air, a main approach is to use cavity quantum electrodynamics (cQED). In this regard, circular Bragg gratings have achieved excellent results in the NIR regime [1] [2] . Using the existing fiber network, especially single-photons in the telecom O-band are favorable not only because of zero wave-packet dispersion but also for wavelength division multiplexing with classical communication signals in the telecom C-band.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 21, 2021•1 citation

Efficient single-photon sources at telecom wavelength with fiber-optic interface (Conference Presentation)

Chang-Min Lee, Mustafa Atabey Buyukkaya, Shahriar Aghaeimeibodi +2 more

Bright fiber-coupled single photon sources are essential components for practical quantum network. In this work, we present a bright single photon source based on an InAs/InP quantum dot emitting at telecom wavelengths. We designed a nanobeam with a photonic crystal mirror at the other end and a tapered coupler at the other end enabling both directional emission and gaussian-like far-field profile. We detected fiber-coupled single photon count rate of 1.1 MHz with 40 MHz pumping rate. Considering losses from optics and spectral filters, we achieved collection efficiency into first lens of 68% and a total fiber collection efficiency of 8.2%.

Quantum Dots and Nanostructures: Growth, Characterization, and Modeling•Mar 10, 2020•0 citations
Deterministic sources of quantum light are becoming increasingly relevant in the development of quantum communication, particularly in deployed fiber networks. Therefore, efficient fiber-coupled sources at telecom wavelength are highly sought after. With this goal in mind, we systematically investigate the fiber coupling performance of quantum dots in optical resonators under three experimental configurations. We quantify coupling efficiency and sensitivity to spatial displacement for single-mode fibers with 3D printed optics on their tip, and benchmark their behavior over a commercial cleaved-cut fiber and a standard optical setup. The reduction of the required optical elements when operating with a lensed or a bare fiber allows for an increased end-to-end efficiency by a factor of up to 3.0 +/- 0.2 over a standard setup. For the perspective of realizing a mechanically stable fiber-coupled source, we precisely quantify the spatial tolerance to fiber-cavity misalignment, observing less than 50 % count rate drop for several micrometers displacement. These results will play a key role in the future development of fiber-coupled sources of quantum light.
Abstract Deterministic sources of quantum light are becoming increasingly relevant in the development of quantum communication, particularly in deployed fiber networks. Therefore, efficient fiber‐coupled sources at telecom wavelength are highly sought after. With this goal in mind, the fiber coupling performance of quantum dots is systematically investigated in optical resonators under three experimental configurations. For the first time coupling efficiency and sensitivity are quantified to spatial displacement for single‐mode fibers with 3D printed optics on their tip, and benchmark their behavior over a commercial cleaved‐cut fiber and a standard optical setup. The reduction of the required optical elements when operating with a lensed or a bare fiber allows for an increased end‐to‐end efficiency over a standard setup. For the perspective of realizing a mechanically stable fiber‐coupled source, the spatial tolerance is precisely quantified to fiber‐cavity misalignment, observing less than count rate drop for several micrometers displacement. In the spirit of precise quantification and reproducibility, the experiments are performed on multiple photonic resonators. These results will play a key role in the future development of fiber‐coupled sources of quantum light.
We present a design study of quantum light sources based on hybrid circular Bragg gratings (CBGs) for emission wavelengths in the telecom O-band. The evaluated CBG designs show photon extraction efficiencies > 95% and Purcell factors close to 30. Using simulations based on the finite element method, and considering the influence of possible fabrication imperfections, we identify optimized high-performance CBG designs which are robust against structural aberrations. In particular, full 3D simulations reveal that the designs show robustness regarding lateral deviations of the emitter position in the device well within reported positioning accuracies of deterministic fabrication technologies. Furthermore, we investigate the coupling of the evaluated hybrid CBG designs to single-mode optical fibers, which is particularly interesting for the development of practical quantum light sources. We obtain coupling efficiencies of up to 77% for off-the-shelf fibers, and again proof robustness against fabrication imperfections. Our results show prospects for the fabrication of close-to-ideal fiber-coupled quantum light sources for long distance quantum communication.
For quantum light sources in everyday telecommunication networks, quantum science needs to be fully transformed into quantum technology. The first necessary step to move outside a well-controlled lab environment requires the use of quantum light sources operating in the technologically relevant telecom O- and C-band. This can be provided using epitaxial quantum dots as deterministic sources of quantum light. Particularly intriguing is that emitters operating at telecom wavelengths are rapidly catching up with their short wavelength counterparts in terms of performances. Here, we make a decisive step forward in the development of quantum communication networks: a state-of-the-art source of quantum light, a semiconductor quantum dot (QD), with record coincidence rate for entangled photon emission in the telecom C-band, is operated inside an optimized rack-based setup. This setup includes a tunable pulsed laser for the QD excitation (from quasi- to fully resonant excitation), all optics for the excitation filtering, and QD signal coupling into single-mode fibers. Overall, the setup allows for above 50%50\%50% transmission for both exciton and biexciton photons. These results show that quantum dots-based telecom light sources can now be transported and integrated into existing fiber infrastructures, an important step to demonstrate the feasibility of the upcoming quantum internet.
High-performance solid-state quantum sources in the telecom band are of paramount importance for long-distance quantum communications and the quantum Internet by taking advantage of a low-loss optical fiber network. Here, we demonstrate bright telecom-wavelength single-photon sources based on In(Ga)As/GaAs quantum dots (QDs) deterministically coupled to hybrid circular Bragg resonators (h-CBRs) by using a wide-field fluorescence imaging technique. The QD emissions are redshifted toward the telecom O-band by using an ultra-low InAs growth rate and an InGaAs strain reducing layer. Single-photon emissions under both continuous wave (CW) and pulsed operations are demonstrated, showing high brightness with count rates of 1.14 MHz and 0.34 MHz under saturation powers and single-photon purities of g ( 2 ) ( 0 ) = 0.11 ± 0.02 (CW) and g ( 2 ) ( 0 ) = 0.087 ± 0.003 (pulsed) at low excitation powers. A Purcell factor of 4.2 with a collection efficiency of 11.2 % ± 1 % at the first lens is extracted, suggesting efficient coupling between the QD and h-CBR. Our work contributes to the development of highly efficient single-photon sources in the telecom band for fiber-based quantum communication and future distributed quantum networks.
In the field of quantum communication and quantum cryptography, the need for bright non-classical light sources remains a key requirement. Semiconductor quantum dots (QDs) have proven to be excellent candidates also being able to emit single-photons in the much sought after telecom bands. To overcome the high refractive index contrast between the semiconductor matrix and air, a main approach is to use cavity quantum electrodynamics (cQED). In this regard, circular Bragg gratings have achieved excellent results in the NIR regime [1] [2] . Using the existing fiber network, especially single-photons in the telecom O-band are favorable not only because of zero wave-packet dispersion but also for wavelength division multiplexing with classical communication signals in the telecom C-band.
Bright fiber-coupled single photon sources are essential components for practical quantum network. In this work, we present a bright single photon source based on an InAs/InP quantum dot emitting at telecom wavelengths. We designed a nanobeam with a photonic crystal mirror at the other end and a tapered coupler at the other end enabling both directional emission and gaussian-like far-field profile. We detected fiber-coupled single photon count rate of 1.1 MHz with 40 MHz pumping rate. Considering losses from optics and spectral filters, we achieved collection efficiency into first lens of 68% and a total fiber collection efficiency of 8.2%.