The performance of light microscopes is limited by the stochastic nature of light, which exists in discrete packets of energy known as photons. Randomness in the times that photons are detected introduces shot noise, which fundamentally constrains sensitivity, resolution and speed1. Although the long-established solution to this problem is to increase the intensity of the illumination light, this is not always possible when investigating living systems, because bright lasers can severely disturb biological processes2,3,4. Theory predicts that biological imaging may be improved without increasing light intensity by using quantum photon correlations1,5. Here we experimentally show that quantum correlations allow a signal-to-noise ratio beyond the photodamage limit of conventional microscopy. Our microscope is a coherent Raman microscope that offers subwavelength resolution and incorporates bright quantum correlated illumination. The correlations allow imaging of molecular bonds within a cell with a 35 per cent improved signal-to-noise ratio compared with conventional microscopy, corresponding to a 14 per cent improvement in concentration sensitivity. This enables the observation of biological structures that would not otherwise be resolved. Coherent Raman microscopes allow highly selective biomolecular fingerprinting in unlabelled specimens6,7, but photodamage is a major roadblock for many applications8,9. By showing that the photodamage limit can be overcome, our work will enable order-of-magnitude improvements in the signal-to-noise ratio and the imaging speed.
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The data that support the findings of this study are included in the Supplementary Information. This includes data quantifying the detector design and performance (Supplementary Figs. 3–5); example power spectral densities of the stimulated Raman signal-to-noise ratio with and without squeezing (Supplementary Fig. 6); the raw measured power spectral densities of detector electronic noise, shot-noise and squeezing (Supplementary Fig. 7); experimental measurements of the squeezed variance and classical deamplification of the Stokes field as a function of the optical parametric amplifier pump power (Supplementary Fig. 9); the photocurrent power spectral density used to determine the concentration sensitivity when probing the CH aromatic stretch band in polystyrene (Supplementary Fig. 10); measurements of cell photodamage (Supplementary Fig. 11); and comparative cell images with and without quantum enhancement (Supplementary Fig. 12). Further data are available from the corresponding author upon reasonable request. Source data are provided with this paper.
Taylor, M. A. & Bowen, W. P. Quantum metrology and its application in biology. Phys. Rep. 615, 1–59 (2016).
Li, B., Wu, C., Wang, M., Charan, K. & Xu, C, An adaptive excitation source for high-speed multiphoton microscopy. Nat. Methods 17, 163–166 (2020).
Wäldchen, S., Lehmann, J., Klein, T., Van De Linde, S. & Sauer, M. Light-induced cell damage in live-cell super-resolution microscopy. Sci. Rep. 5, 15348 (2015).
Mauranyapin, N. P., Madsen, L. S., Taylor, M. A., Waleed, M. & Bowen, W. P. Evanescent single-molecule biosensing with quantum-limited precision. Nat. Photon. 11, 477–481 (2017).
Slusher, R. E. Quantum optics in the ’80s. Opt. Photon. News 1, 27–30 (1990).
Cheng, J.-X. & Sunney Xie, X. Vibrational spectroscopic imaging of living systems: an emerging platform for biology and medicine. Science 350, aaa8870 (2015).
Wei, L. et al. Super-multiplex vibrational imaging. Nature 544, 465–470 (2017).
Camp, C. H. Jr & Cicerone, M. T. Chemically sensitive bioimaging with coherent Raman scattering. Nat. Photon. 9, 295–305 (2015).
Fu, Y., Wang, H., Shi, R. & Cheng, J.-X. Characterization of photodamage in coherent anti-Stokes Raman scattering microscopy. Opt. Express 14, 3942–3951 (2006).
Sigal, Y. M., Zhou, R. & Zhuang, X. Visualizing and discovering cellular structures with super-resolution microscopy. Science 361, 880–887 (2018).
Alex, M. et al. Applying systems-level spectral imaging and analysis to reveal the organelle interactome. Nature 546, 162–167 (2017).
Adam, Y. et al. Voltage imaging and optogenetics reveal behaviour-dependent changes in hippocampal dynamics. Nature 569, 413–417 (2019).
Schermelleh, L. et al. Super-resolution microscopy demystified. Nat. Cell Biol. 21, 72–84 (2019).
Sewell, R. J., Napolitano, M., Behbood, N., Colangelo, G. & Mitchell, M. W. Certified quantum non-demolition measurement of a macroscopic material system. Nat. Photon. 7, 517–520 (2013).
Aasi, J. et al. Enhanced sensitivity of the LIGO gravitational wave detector by using squeezed states of light. Nat. Photon. 7, 613–619 (2013).
Giovannetti, V., Lloyd, S. & Maccone, L. Advances in quantum metrology. Nat. Photon. 5, 222–229 (2011).
Moreau, P.-A., Toninelli, E., Gregory, T. & Padgett, M. J. Imaging with quantum states of light. Nat. Rev. Phys. 1, 367–380 (2019).
Brida, G., Genovese, M. & Ruo Berchera, I. Experimental realization of sub-shot-noise quantum imaging. Nat. Photon. 4, 227–230 (2010).
Defienne, H., Reichert, M., Fleischer, J. W. & Faccio, D. Quantum image distillation. Sci. Adv. 5, eaax0307 (2019).
Sabines-Chesterking, J. et al. Twin-beam sub-shot-noise raster-scanning microscope. Opt. Express 27, 30810–30818 (2019).
Samantaray, N., Ruo-Berchera, I., Meda, A. & Genovese, M. Realization of the first sub-shot-noise wide field microscope. Light Sci. Appl. 6, e17005 (2017).
Gregory, T., Moreau, P.-A., Toninelli, E. & Padgett, M. J. Imaging through noise with quantum illumination. Sci. Adv. 6, eaay2652 (2020).
Israel, Y., Rosen, S. & Silberberg, Y. Supersensitive polarization microscopy using NOON states of light. Phys. Rev. Lett. 112, 103604 (2014).
Ono, T., Okamoto, R. & Takeuchi, S. An entanglement-enhanced microscope. Nat. Commun. 4, 2426 (2013).
Lemos, G. B. et al. Quantum imaging with undetected photons. Nature 512, 409–412 (2014).
Kalashnikov, D. A., Paterova, A. V., Kulik, S. P. & Krivitsky, L. A. Infrared spectroscopy with visible light. Nat. Photon. 10, 98–101 (2016).
Paterova, A. V., Yang, H., An, C., Kalashnikov, D. A. & Krivitsky, L. A. Tunable optical coherence tomography in the infrared range using visible photons. Quantum Sci. Technol. 3, 025008 (2018).
Zhang, L. et al. Spectral tracing of deuterium for imaging glucose metabolism. Nat. Biomed. Eng. 3, 402–413 (2019).
Tian, F. et al. Monitoring peripheral nerve degeneration in ALS by label-free stimulated Raman scattering imaging. Nat. Commun. 7, 13283 (2016).
Liu, B. et al. Label-free spectroscopic detection of membrane potential using stimulated Raman scattering. Appl. Phys. Lett. 106, 173704 (2015).
Konstanze, T. et al. Phenazine production promotes antibiotic tolerance and metabolic heterogeneity in Pseudomonas aeruginosa biofilms. Nat. Commun. 10, 762 (2019).
Saar, B. G. et al. Video-rate molecular imaging in vivo with stimulated Raman scattering. Science 330, 1368–1370 (2010).
Freudiger, C. W. et al. Stimulated Raman scattering microscopy with a robust fibre laser source. Nat. Photon. 8, 153–159 (2014).
Freudiger, C. W. et al. Label-free biomedical imaging with high sensitivity by stimulated Raman scattering microscopy. Science 322, 1857–1861 (2008).
Pooser, R. C. & Lawrie, B. Plasmonic trace sensing below the photon shot noise limit. ACS Photon. 3, 8–13 (2016).
Dowran, M., Kumar, A., Lawrie, B. J., Pooser, R. C. & Marino, A. M. Quantum-enhanced plasmonic sensing. Optica 5, 628–633 (2018).
Michael, A. et al. Biological measurement beyond the quantum limit. Nat. Photon. 7, 229–233 (2013).
Michael, A. et al. Subdiffraction-limited quantum imaging within a living cell. Phys. Rev. X 4, 011017 (2014).
Tenne, R. et al. Super-resolution enhancement by quantum image scanning microscopy. Nat. Photon. 13, 116–122 (2019).
Phan, N. M., Cheng, M. F., Bessarab, D. A. & Krivitsky, L. A. Interaction of fixed number of photons with retinal rod cells. Phys. Rev. Lett. 112, 213601 (2014).
Choi, Y. et al. Shot-noise-limited two-color stimulated Raman scattering microscopy with a balanced detection scheme. J. Phys. Chem. B 124, 2591–2599 (2020).
de Andrade, R. B. et al. Quantum-enhanced continuous-wave stimulated Raman spectroscopy. Optica 7, 470–475 (2020).
Triginer Garces, G. et al. Quantum-enhanced stimulated emission detection for label-free microscopy. Appl. Phys. Lett. 117, 024002 (2020).
Okuno, M. et al. Quantitative CARS molecular fingerprinting of single living cells with the use of the maximum entropy method. Angew. Chem. 122, 6925–6929 (2010).
Kochan, K., Peng, H., Wood, B. R. & Haritos, V. S. Single cell assessment of yeast metabolic engineering for enhanced lipid production using Raman and AFM-IR imaging. Biotechnol. Biofuels 11, 106 (2018).
A Roadmap for Quantum Technologies in the UK 16 (UK Quantum Technologies Programme, 2015); https://epsrc.ukri.org/newsevents/pubs/quantumtechroadmap
Vahlbruch, H., Mehmet, M., Danzmann, K. & Schnabel, R. Detection of 15 dB squeezed states of light and their application for the absolute calibration of photoelectric quantum efficiency. Phys. Rev. Lett. 117, 110801 (2016).
Hoover, E. E. & Squier, J. A. Advances in multiphoton microscopy technology. Nat. Photon. 7, 93–101 (2013).
Zong, C. et al. Plasmon-enhanced stimulated Raman scattering microscopy with single-molecule detection sensitivity. Nat. Commun. 10, 5318 (2019).
Michael, Y., Bello, L., Rosenbluh, M. & Pe’er, A. Squeezing-enhanced Raman spectroscopy. npj Quantum Inf. 5, 81 (2019).
We acknowledge W. Wasserman for sourcing the yeast cells in trying circumstances, U. Hoff for contributions to the construction of the apparatus and APE GmbH for support related to the laser system. This material is based upon work supported by the Air Force Office of Scientific Research under award number FA9550-17-1-0397. It was also supported by the Australian Research Council Centre of Excellence for Engineered Quantum Systems (EQUS, CE170100009). W.P.B. acknowledges the Australian Research Council Future Fellowship, FT140100650. M.A.T. acknowledges the Australian Research Council Discovery Early Career Research Award, DE190100641.
The authors declare no competing interests.
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Casacio, C.A., Madsen, L.S., Terrasson, A. et al. Quantum-enhanced nonlinear microscopy. Nature 594, 201–206 (2021). https://doi.org/10.1038/s41586-021-03528-w