Entangled-photon super-resolution microscopy and foundations
ORAL · Invited
Abstract
Entangled photons exhibit nonclassical properties that enable quantum imaging to surpass classical limits. Quantum imaging can achieve spatial super-resolution beyond the diffraction limit through coincidence detection. In particular, quantum imaging with Heisenberg scaling enhances resolution linearly with the number of entangled quanta, outperforming the square-root scaling of standard quantum approaches. We present wide-field quantum microscopy based on coincidence detection in a symmetric configuration that enables the Heisenberg scaling.
To overcome long-standing limitations of quantum imaging—including low signal-to-noise ratios (SNR), limited resolvable pixel counts, challenges in biological imaging, and inability to quantify full birefringence—we introduce Imaging by Coincidence from Entanglement (ICE). By leveraging spatial and polarization entanglement, ICE significantly improves SNR, resolution, and compatibility with biological samples. Polarization entanglement in ICE also enables quantitative birefringence imaging, where both the phase retardation and the principal axis angle of refractive index can be measured remotely and without altering the input polarization state. ICE also demonstrates up to 25-fold suppression of stray light compared to classical imaging.
Additionally, we present Quantum Microscopy by Coincidence (QMC) using a balanced-path symmetric setup. Entangled photon pairs traveling through matched optical paths behave like a single photon of half the wavelength, resulting in a twofold improvement in spatial resolution. QMC also achieves up to 155-fold stronger resistance to stray light, along with markedly improved imaging speed and contrast-to-noise ratio. These low-light, noninvasive characteristics of QMC make it suitable for biological applications, including cancer cell imaging. Our theoretical and experimental results establish QMC as a promising approach for wide-field, high-resolution quantum bioimaging at the microscopic scale.
To overcome long-standing limitations of quantum imaging—including low signal-to-noise ratios (SNR), limited resolvable pixel counts, challenges in biological imaging, and inability to quantify full birefringence—we introduce Imaging by Coincidence from Entanglement (ICE). By leveraging spatial and polarization entanglement, ICE significantly improves SNR, resolution, and compatibility with biological samples. Polarization entanglement in ICE also enables quantitative birefringence imaging, where both the phase retardation and the principal axis angle of refractive index can be measured remotely and without altering the input polarization state. ICE also demonstrates up to 25-fold suppression of stray light compared to classical imaging.
Additionally, we present Quantum Microscopy by Coincidence (QMC) using a balanced-path symmetric setup. Entangled photon pairs traveling through matched optical paths behave like a single photon of half the wavelength, resulting in a twofold improvement in spatial resolution. QMC also achieves up to 155-fold stronger resistance to stray light, along with markedly improved imaging speed and contrast-to-noise ratio. These low-light, noninvasive characteristics of QMC make it suitable for biological applications, including cancer cell imaging. Our theoretical and experimental results establish QMC as a promising approach for wide-field, high-resolution quantum bioimaging at the microscopic scale.
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Publication: 1. [He, Z.; Zhang, Y.; Tong, X.]; Li, L.; Wang, L. V.; "Heisenberg Scaling Quantum Microscopy: Experiment and Theory," ArXiv preprint arXiv:2303.04948 (2025)
2. [Zhang, Y.; He, Z.; Tong, X.]; Garrett, D. C.; Cao, R.; Wang, L. V.; "Quantum imaging of biological organisms through spatial and polarization entanglement," Science Advances 10(10) (2024)
3. [He, Z.; Zhang, Y.; Tong, X.]; Li, L.; Wang, L. V.; "Quantum microscopy of cells at the Heisenberg limit," Nature Communications 14(1) 2441 (2023)
Presenters
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Lihong V Wang
- California Institute of Technology
- Cal Tech