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:2505.10338 · Optica Quantum

Telecom-to-visible quantum frequency converter on a silicon nitride chip

Sidarth Raghunathan, Richard C. Oliver, Yun Zhao, Karl J. McNulty, Chaitali Joshi, Michal F. Lipson, Alexander L. Gaeta

Published Jun 12, 2025• 6 citations
arXivHTMLPDF

Abstract

Quantum frequency conversion serves a key role in the realization of hybrid quantum networks by interfacing between wavelength-incompatible platforms. Here we present what is believed to be the first quantum frequency converter connecting visible and telecom domains on a silicon nitride (SiN) chip, using Bragg-scattering four-wave mixing to upconvert heralded single photons from 1260 to 698 nm, which covers a 192 THz span. We examine the noise sources in SiN and devise approaches to suppress noise photons at the source and target frequencies to enable measurements at the single-photon level. We demonstrate an on-chip conversion efficiency of 5% in photon flux and describe design modifications that can be implemented to significantly improve it. Our results pave the way for the implementation of complementary metal-oxide-semiconductor (CMOS)-compatible devices in quantum networks.

DOI
10.1364/opticaq.563123

Related papers

SiN waveguides for ultra-broadband visible-telecom photon pairs

Vijay, Shivani Sharma, Vivek Venkataraman +1 more

Abstract Broadband frequency-correlated photon-pair sources could enable the realization of various quantum information technologies especially WDM-QKD (wavelength division multiplexed quantum key distribution) accommodating multiple users with enhanced data transmission rates. The wide transparency window, negligible nonlinear losses, and con- siderable refractive index contrast of silicon nitride (SiN) on insulator (SiO2) platform makes it an ideal material system for designing CMOS- compatible integrated photon sources based on spontaneous four-wave mixing (SFWM). We propose simple rectangular cross-section, few- cm long SiN waveguide designs capable of generating ultra-broadband frequency-correlated photon pairs via SFWM, exceeding an octave in bandwidth spanning the visible-to-telecom wavelengths (∼700-1700nm for ∼1-μm pump) with a spectral brightness of >2.5×104 photon pairs/s/nm/mW2. Such compact sources, spanning the entire telecom spectrum (across O, E, S, C, L, and U bands) on one side and cover- ing most of the major atomic transitions used in ultracold gases and solid-state based quantum memories on the other side, could poten- tially be employed in large-scale multi channel hybrid (free space + fiber) quantum networking schemes in addition to the heralding of telecom single photons by utilizing high efficiency visible detectors.

Optical and Quantum Electronics•May 11, 2023•5 citations

A chip-scale, telecommunications-band frequency conversion interface for quantum emitters

Imad H. Agha, Serkan Ateş, Marcelo Davanço +1 more

We describe a chip-scale, telecommunications-band frequency conversion interface designed for low-noise operation at wavelengths desirable for common single photon emitters. Four-wave-mixing Bragg scattering in silicon nitride waveguides is used to demonstrate frequency upconversion and downconversion between the 980 nm and 1550 nm wavelength regions, with signal-to-background levels > 10 and conversion efficiency of ≈ -60 dB at low continuous wave input pump powers (< 50 mW). Finite element simulations and the split-step Fourier method indicate that increased input powers of ≈ 10 W (produced by amplified nanosecond pulses, for example) will result in a conversion efficiency > 25 % in existing geometries. Finally, we present waveguide designs that can be used to connect shorter wavelength (637 nm to 852 nm) quantum emitters with 1550 nm.

arXiv:1304.5754•Optics Express•Sep 6, 2013•41 citations

Proposal for noise-free visible-telecom quantum frequency conversion through third-order sum and difference frequency generation

Xiyuan Lu, Gregory T. Moille, Ashutosh Rao +1 more

Quantum frequency conversion (QFC) between the visible and telecom is a key to connect quantum memories in fiber-based quantum networks. Current methods for linking such widely separated frequencies, such as sum/difference frequency generation and four-wave mixing Bragg scattering, are prone to broadband noise generated by the pump laser(s). To address this issue, we propose to use third-order sum/difference frequency generation (TSFG/TDFG) for an upconversion/downconversion QFC interface. In this process, two long wavelength pump photons combine their energy and momentum to mediate frequency conversion across the large spectral gap between the visible and telecom bands, which is particularly beneficial from the noise perspective. We show that waveguide-coupled silicon nitride microring resonators can be designed for efficient QFC between 606 and 1550 nm via a 1990 nm pump through TSFG/TDFG. We simulate the device dispersion and coupling, and from the simulated parameters, estimate that the frequency conversion can be efficient (${\gt}80 \%$) at 50 mW pump power. Our results suggest that microresonator TSFG/TDFG is promising for compact, scalable, and low-power QFC across large spectral gaps.

arXiv:2010.06811•Optics Letters•Dec 7, 2020•11 citations

Telecom-to-Visible Frequency Conversion in a SiN Microresonator

Sidarth Raghunathan, Richard C. Oliver, Yun Peng Zhao +3 more

We demonstrate frequency conversion between 1283 nm and 705 nm using Bragg scattering four-wave mixing in a microresonator, which represents the largest frequency span demonstrated. Our noise measurements suggest it is suitable for quantum applications.

•Jan 1, 2024•0 citations

CMOS-Compatible Source Design for Visible-Telecom Photon-Pairs With Simultaneous Polarization-Entanglement and Spectral-Purity

Vijay, Joyee Ghosh, Vivek Venkataraman

We propose integrated photonic sources based on spontaneous four-wave mixing (SFWM) in dispersion engineered silicon nitride (SiN) nanowaveguides capable of generating spectrally-pure polarization-entangled photon-pairs bridging the visible-NIR and telecom bands. A simple silica-clad SiN waveguide design with height 640 nm and width in the range 860–960 nm can generate polarization-entangled photon pairs that simultaneously offers high heralded single photon purity of$>$99% and concurrence upto 0.99, with signal and idler lying in the range$\sim$736–740 nm and$\sim$1460–1560 nm, respectively, employing a pulsed pump (BW$\gtrsim$0.25–3 THz) of wavelength near$\sim$1-$\mu$m. Slightly different waveguide height of 620 nm and corresponding waveguide widths in the range 1040–1180 nm, offering the same purity and concurrence standards, can also address various quantum memories demonstrated at the visible-NIR wavelengths of$\sim$775–800 nm with a telecom band interface. Such CMOS-compatible on-chip sources of spectrally-pure polarization-entangled photon pairs can potentially be employed in a scalable manner for various optical quantum technologies.

IEEE Journal of Selected Topics in Quantum Electronics•Jan 15, 2025•0 citations

Low-noise chip-based frequency conversion by four-wave-mixing Bragg scattering in SiN_x waveguides

Imad H. Agha, Marcelo Davanço, Bryce Thurston +1 more

Low-noise, tunable wavelength-conversion through nondegenerate four-wave mixing Bragg scattering in SiN(x) waveguides is experimentally demonstrated. Finite element method simulations of waveguide dispersion are used with the split-step Fourier method to predict device performance. Two 1550 nm wavelength band pulsed pumps are used to achieve tunable conversion of a 980 nm signal over a range of 5 nm with a peak conversion efficiency of ≈5%. The demonstrated Bragg scattering process is suitable for frequency conversion of quantum states of light.

arXiv:1203.6558•Optics Letters•Jul 13, 2012•70 citations
Quantum frequency conversion serves a key role in the realization of hybrid quantum networks by interfacing between wavelength-incompatible platforms. Here we present what is believed to be the first quantum frequency converter connecting visible and telecom domains on a silicon nitride (SiN) chip, using Bragg-scattering four-wave mixing to upconvert heralded single photons from 1260 to 698 nm, which covers a 192 THz span. We examine the noise sources in SiN and devise approaches to suppress noise photons at the source and target frequencies to enable measurements at the single-photon level. We demonstrate an on-chip conversion efficiency of 5% in photon flux and describe design modifications that can be implemented to significantly improve it. Our results pave the way for the implementation of complementary metal-oxide-semiconductor (CMOS)-compatible devices in quantum networks.
Abstract Broadband frequency-correlated photon-pair sources could enable the realization of various quantum information technologies especially WDM-QKD (wavelength division multiplexed quantum key distribution) accommodating multiple users with enhanced data transmission rates. The wide transparency window, negligible nonlinear losses, and con- siderable refractive index contrast of silicon nitride (SiN) on insulator (SiO2) platform makes it an ideal material system for designing CMOS- compatible integrated photon sources based on spontaneous four-wave mixing (SFWM). We propose simple rectangular cross-section, few- cm long SiN waveguide designs capable of generating ultra-broadband frequency-correlated photon pairs via SFWM, exceeding an octave in bandwidth spanning the visible-to-telecom wavelengths (∼700-1700nm for ∼1-μm pump) with a spectral brightness of >2.5×104 photon pairs/s/nm/mW2. Such compact sources, spanning the entire telecom spectrum (across O, E, S, C, L, and U bands) on one side and cover- ing most of the major atomic transitions used in ultracold gases and solid-state based quantum memories on the other side, could poten- tially be employed in large-scale multi channel hybrid (free space + fiber) quantum networking schemes in addition to the heralding of telecom single photons by utilizing high efficiency visible detectors.
We describe a chip-scale, telecommunications-band frequency conversion interface designed for low-noise operation at wavelengths desirable for common single photon emitters. Four-wave-mixing Bragg scattering in silicon nitride waveguides is used to demonstrate frequency upconversion and downconversion between the 980 nm and 1550 nm wavelength regions, with signal-to-background levels > 10 and conversion efficiency of ≈ -60 dB at low continuous wave input pump powers (< 50 mW). Finite element simulations and the split-step Fourier method indicate that increased input powers of ≈ 10 W (produced by amplified nanosecond pulses, for example) will result in a conversion efficiency > 25 % in existing geometries. Finally, we present waveguide designs that can be used to connect shorter wavelength (637 nm to 852 nm) quantum emitters with 1550 nm.
Quantum frequency conversion (QFC) between the visible and telecom is a key to connect quantum memories in fiber-based quantum networks. Current methods for linking such widely separated frequencies, such as sum/difference frequency generation and four-wave mixing Bragg scattering, are prone to broadband noise generated by the pump laser(s). To address this issue, we propose to use third-order sum/difference frequency generation (TSFG/TDFG) for an upconversion/downconversion QFC interface. In this process, two long wavelength pump photons combine their energy and momentum to mediate frequency conversion across the large spectral gap between the visible and telecom bands, which is particularly beneficial from the noise perspective. We show that waveguide-coupled silicon nitride microring resonators can be designed for efficient QFC between 606 and 1550 nm via a 1990 nm pump through TSFG/TDFG. We simulate the device dispersion and coupling, and from the simulated parameters, estimate that the frequency conversion can be efficient (>80%{\gt}80 \%>80%) at 50 mW pump power. Our results suggest that microresonator TSFG/TDFG is promising for compact, scalable, and low-power QFC across large spectral gaps.
We propose integrated photonic sources based on spontaneous four-wave mixing (SFWM) in dispersion engineered silicon nitride (SiN) nanowaveguides capable of generating spectrally-pure polarization-entangled photon-pairs bridging the visible-NIR and telecom bands. A simple silica-clad SiN waveguide design with height 640 nm and width in the range 860–960 nm can generate polarization-entangled photon pairs that simultaneously offers high heralded single photon purity of$>9999% and concurrence upto 0.99, with signal and idler lying in the range99\sim736–740nmand736–740 nm and736–740nmand\sim1460–1560nm,respectively,employingapulsedpump(BW1460–1560 nm, respectively, employing a pulsed pump (BW1460–1560nm,respectively,employingapulsedpump(BW\gtrsim0.25–3THz)ofwavelengthnear0.25–3 THz) of wavelength near0.25–3THz)ofwavelengthnear\sim1−1-1−\mum.Slightlydifferentwaveguideheightof620nmandcorrespondingwaveguidewidthsintherange1040–1180nm,offeringthesamepurityandconcurrencestandards,canalsoaddressvariousquantummemoriesdemonstratedatthevisible−NIRwavelengthsofm. Slightly different waveguide height of 620 nm and corresponding waveguide widths in the range 1040–1180 nm, offering the same purity and concurrence standards, can also address various quantum memories demonstrated at the visible-NIR wavelengths ofm.Slightlydifferentwaveguideheightof620nmandcorrespondingwaveguidewidthsintherange1040–1180nm,offeringthesamepurityandconcurrencestandards,canalsoaddressvariousquantummemoriesdemonstratedatthevisible−NIRwavelengthsof\sim$775–800 nm with a telecom band interface. Such CMOS-compatible on-chip sources of spectrally-pure polarization-entangled photon pairs can potentially be employed in a scalable manner for various optical quantum technologies.
Low-noise, tunable wavelength-conversion through nondegenerate four-wave mixing Bragg scattering in SiN(x) waveguides is experimentally demonstrated. Finite element method simulations of waveguide dispersion are used with the split-step Fourier method to predict device performance. Two 1550 nm wavelength band pulsed pumps are used to achieve tunable conversion of a 980 nm signal over a range of 5 nm with a peak conversion efficiency of ≈5%. The demonstrated Bragg scattering process is suitable for frequency conversion of quantum states of light.