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:1811.07436 · Physical Review Applied

High-Contrast Quantum Imaging with Time-Gated Fluorescence Detection

Xiang-Dong Chen, Yu Zheng, Bo Du, Deng-Feng Li, Shen Li, Yang Dong, Guang-Can Guo, Fang-Wen Sun

Published Jun 11, 2019• 12 citations
arXivHTMLPDF

Abstract

For various applications based on nitrogen-vacancy centers in diamond, high-contrast optical detection of the spin state is one of the most important techniques, and is limited by the probability of nonradiative intersystem crossing. Utilizing a time gate for fluorescence detection, this work shows that the spin-state signal's contrast is improved by partially detecting the fluorescence photons. Subsequently, information hidden in the high-level background can be revealed. This technique can help to improve the performance of quantum sensing and imaging with nitrogen-vacancy centers, especially in noisy environments.

DOI
10.1103/physrevapplied.11.064024

Related papers

Stimulated emission assisted time-gated detection of a solid-state spin

Bo-Wen Zhao, Xiang-Dong Chen, Enhui Wang +6 more

The nitrogen vacancy (NV) center in diamond is studied widely for magnetic field and temperature sensing at the nanoscale. Usually, the fluorescence is recorded to estimate the spin state of the NV center. Here we applied a time-gating technique to improve the contrast of the spin-dependent fluorescence. A NIR pulsed laser pumped the stimulated emission of the NV center and depleted the spontaneous emission that was excited by a green laser. We changed the relative delay between the NIR laser and the green laser. Then the spontaneous emission of the NV center in varied time windows was extracted by comparing the fluorescence intensities with and without the NIR laser. The results showed that the spin-dependent fluorescence contrast could be improved by approximately 1.8 times by applying the time gating. The background of the environment was eliminated due to temporal filtering. This work demonstrates that the stimulated emission assisted time-gating technique can be used to improve the performance of an NV center sensor in a noisy environment.

Applied Optics•Jun 22, 2020•3 citations

Temporal filtered quantum sensing with the nitrogen-vacancy center in diamond

Florian Boehm, Yan Liu, Chengliang Yue +5 more

Nitrogen vacancy centers in diamond are among the leading solid state quantum platforms, offering exceptional spatial resolution and sensitivity for applications such as magnetic field sensing, thermometry, and bioimaging. However, in high background environments,such as those encountered in in vitro diagnostics, the performance of NV based sensors can be compromised by strong background fluorescence, particularly from substrates such as nitrocellulose. In this work, we analytically and experimentally investigate the use of pulsed laser excitation combined with time gating techniques to suppress background fluorescence and enhance the signal to noise ratio in NV based quantum sensing, with an emphasis on spin enhanced biosensing. Through experimental studies using mixed ensembles of silicon vacancy and NV centers in bulk diamond, as well as fluorescent nanodiamonds on NC substrates, we demonstrate significant improvements in NV spin resonance visibility, demonstrated by an increase of the SNR by up to 4x, and a resulting measurement time reduction by 16x. The presented technique and results here can help significantly increase the readout efficiency and speed in future applications of NV centers in high background environments, such as in IVD, where the NV centers are used as a fluorescent label for biomolecules.

quant-pharXiv:2511.02369•Nov 5, 2025

Photoelectrical imaging and coherent spin-state readout of single nitrogen-vacancy centers in diamond

Petr Siyushev, Miloš Nesládek, Emilie Bourgeois +7 more

Nitrogen-vacancy (NV) centers in diamond have become an important instrument for quantum sensing and quantum information science. However, the readout of NV spin state requires bulky optical setups, limiting fabrication of miniaturized compact devices for practical use. Here we realized photoelectrical detection of magnetic resonance as well as Rabi oscillations on a single-defect level. Furthermore, photoelectrical imaging of individual NV centers at room temperature was demonstrated, surpassing conventional optical readout methods by providing high imaging contrast and signal-to-noise ratio. These results pave the way toward fully integrated quantum diamond devices.

Science•Feb 14, 2019•194 citations

Spin Contrast of Purcell-Enhanced Nitrogen-Vacancy Centers in Diamond

Simeon Bogdanov, Mikhail Y. Shalaginov, Alexey V. Akimov +9 more

Nitrogen-vacancy centers in diamond allow coherent spin state manipulation and optical readout at room temperature, which has powerful applications in nanoscale sensing. Nanophotonic structures such as plasmonic waveguides, nanoantennae, metamaterials, and metasurfaces can enhance the detected fluorescence rate from such broadband emitters. The fluorescence of the coupled emitter is directed into confined plasmonic modes with high photonic density of states. However, an accurate spin readout requires both high photon counts and a strong contrast between the spin states, both of which can be influenced by the Purcell effect. We introduce a novel method for measuring the spin contrast in large nitrogen-vacancy ensembles. We use this method to study how the photonic density of states must be engineered in order to minimize the uncertainty of spin readout in dense NV ensembles. We describe these results using a kinetic model of the nitrogen-vacancy’s internal dynamics.

Conference on Lasers and Electro-Optics•Jan 1, 2017•0 citations

Quantum sensing with spin defects: principles, progress, and prospects for use cases

Ki-Hwan Kim, Jong Sung Moon, Dongkwon Lee +6 more

Quantum sensing aims to detect signals with unparalleled sensitivity, potentially surpassing classical limitations. Solid-state spin defects, particularly nitrogen-vacancy centers in diamond, have emerged as promising platforms due to their long coherence time, optical addressability, high field sensitivity, and spatial and spectral resolution, making them ideal for sensing and imaging applications. Their compact size and robust performance under room temperature and ambient conditions further enhance their suitability for real-world applications. We provide an overview of quantum sensing principles and explore efforts to improve sensor functionality, including advanced sensing protocols, spatial imaging techniques, and integration with optical systems to enhance detection efficiency. We also highlight recent progress in the applications of these sensors across various use cases, including biomedical diagnostics, semiconductor device inspection, and industrial and military applications.

Advanced Photonics•Sep 24, 2025•7 citations

Efficient signal processing for time-resolved fluorescence detection of nitrogen-vacancy spins in diamond

Anchal Gupta, Luke R. P. Hacquebard, Lilian Childress

Room-temperature fluorescence detection of the nitrogen-vacancy center electronic spin typically has low signal to noise, requiring long experiments to reveal an averaged signal. Here, we present a simple approach to analysis of time-resolved fluorescence data that permits an improvement in measurement precision through signal processing alone. Applying our technique to experimental data reveals an improvement in signal to noise, which is equivalent to a 14% increase in photon collection efficiency. We further explore the dependence of the signal-to-noise ratio on excitation power and analyze our results using a rate equation model. Our results provide a rubric for optimizing fluorescence spin detection, which has direct implications for improving precision of nitrogen-vacancy-based sensors.

arXiv:1511.04407•Journal of the Optical Society of America B•Jan 13, 2016•76 citations
For various applications based on nitrogen-vacancy centers in diamond, high-contrast optical detection of the spin state is one of the most important techniques, and is limited by the probability of nonradiative intersystem crossing. Utilizing a time gate for fluorescence detection, this work shows that the spin-state signal's contrast is improved by partially detecting the fluorescence photons. Subsequently, information hidden in the high-level background can be revealed. This technique can help to improve the performance of quantum sensing and imaging with nitrogen-vacancy centers, especially in noisy environments.
The nitrogen vacancy (NV) center in diamond is studied widely for magnetic field and temperature sensing at the nanoscale. Usually, the fluorescence is recorded to estimate the spin state of the NV center. Here we applied a time-gating technique to improve the contrast of the spin-dependent fluorescence. A NIR pulsed laser pumped the stimulated emission of the NV center and depleted the spontaneous emission that was excited by a green laser. We changed the relative delay between the NIR laser and the green laser. Then the spontaneous emission of the NV center in varied time windows was extracted by comparing the fluorescence intensities with and without the NIR laser. The results showed that the spin-dependent fluorescence contrast could be improved by approximately 1.8 times by applying the time gating. The background of the environment was eliminated due to temporal filtering. This work demonstrates that the stimulated emission assisted time-gating technique can be used to improve the performance of an NV center sensor in a noisy environment.
Nitrogen vacancy centers in diamond are among the leading solid state quantum platforms, offering exceptional spatial resolution and sensitivity for applications such as magnetic field sensing, thermometry, and bioimaging. However, in high background environments,such as those encountered in in vitro diagnostics, the performance of NV based sensors can be compromised by strong background fluorescence, particularly from substrates such as nitrocellulose. In this work, we analytically and experimentally investigate the use of pulsed laser excitation combined with time gating techniques to suppress background fluorescence and enhance the signal to noise ratio in NV based quantum sensing, with an emphasis on spin enhanced biosensing. Through experimental studies using mixed ensembles of silicon vacancy and NV centers in bulk diamond, as well as fluorescent nanodiamonds on NC substrates, we demonstrate significant improvements in NV spin resonance visibility, demonstrated by an increase of the SNR by up to 4x, and a resulting measurement time reduction by 16x. The presented technique and results here can help significantly increase the readout efficiency and speed in future applications of NV centers in high background environments, such as in IVD, where the NV centers are used as a fluorescent label for biomolecules.
Nitrogen-vacancy (NV) centers in diamond have become an important instrument for quantum sensing and quantum information science. However, the readout of NV spin state requires bulky optical setups, limiting fabrication of miniaturized compact devices for practical use. Here we realized photoelectrical detection of magnetic resonance as well as Rabi oscillations on a single-defect level. Furthermore, photoelectrical imaging of individual NV centers at room temperature was demonstrated, surpassing conventional optical readout methods by providing high imaging contrast and signal-to-noise ratio. These results pave the way toward fully integrated quantum diamond devices.
Nitrogen-vacancy centers in diamond allow coherent spin state manipulation and optical readout at room temperature, which has powerful applications in nanoscale sensing. Nanophotonic structures such as plasmonic waveguides, nanoantennae, metamaterials, and metasurfaces can enhance the detected fluorescence rate from such broadband emitters. The fluorescence of the coupled emitter is directed into confined plasmonic modes with high photonic density of states. However, an accurate spin readout requires both high photon counts and a strong contrast between the spin states, both of which can be influenced by the Purcell effect. We introduce a novel method for measuring the spin contrast in large nitrogen-vacancy ensembles. We use this method to study how the photonic density of states must be engineered in order to minimize the uncertainty of spin readout in dense NV ensembles. We describe these results using a kinetic model of the nitrogen-vacancy’s internal dynamics.
Quantum sensing aims to detect signals with unparalleled sensitivity, potentially surpassing classical limitations. Solid-state spin defects, particularly nitrogen-vacancy centers in diamond, have emerged as promising platforms due to their long coherence time, optical addressability, high field sensitivity, and spatial and spectral resolution, making them ideal for sensing and imaging applications. Their compact size and robust performance under room temperature and ambient conditions further enhance their suitability for real-world applications. We provide an overview of quantum sensing principles and explore efforts to improve sensor functionality, including advanced sensing protocols, spatial imaging techniques, and integration with optical systems to enhance detection efficiency. We also highlight recent progress in the applications of these sensors across various use cases, including biomedical diagnostics, semiconductor device inspection, and industrial and military applications.
Room-temperature fluorescence detection of the nitrogen-vacancy center electronic spin typically has low signal to noise, requiring long experiments to reveal an averaged signal. Here, we present a simple approach to analysis of time-resolved fluorescence data that permits an improvement in measurement precision through signal processing alone. Applying our technique to experimental data reveals an improvement in signal to noise, which is equivalent to a 14% increase in photon collection efficiency. We further explore the dependence of the signal-to-noise ratio on excitation power and analyze our results using a rate equation model. Our results provide a rubric for optimizing fluorescence spin detection, which has direct implications for improving precision of nitrogen-vacancy-based sensors.