Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Observation of loss-enhanced magneto-optical effect

Nature Photonics volume 19, pages 109–115 (2025)Cite this article

Subjects

Abstract

Magneto-optical (MO) effects have a pivotal role in modern photonic devices for light manipulation and sensing, but the study of these effects has so far been limited to the MO Faraday and Kerr effects. Conventional MO systems encounter considerable intrinsic losses, markedly hampering their ability to amplify the MO effects. Here we introduce a loss-enhanced MO effect to sublinearly amplify the frequency response of a non-Hermitian optical cavity under different background magnetic fields. This exceptional MO effect relies on an architecture of MO material embedded in a Fabry–Pérot cavity, accompanied by a polarization-dependent optical absorption, that is, linear dichroism, to construct a reconfigurable exceptional point. The experimental results show that two eigenmodes of the Fabry–Pérot cavity exhibit sublinear frequency splitting. By electrically reconfiguring the absorber, the eigenfrequency shift can be adaptively enhanced under different background magnetic fields. Using this effect, we demonstrate the detection of subtle magnetic field variations in a strong background, with the system’s response magnified by a factor exceeding 10 and sensitivity increased threefold compared with its conventional Hermitian counterpart. Our study leverages exceptional physics to study the MO effect and develops a new class of reconfigurable MO devices equipped with enhanced sensitivity for potential integration with photonic systems.

Access through your institution
Buy or subscribe

This is a preview of subscription content, access via your institution

Access options

Access through your institution

Buy this article

  • Purchase on SpringerLink
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Loss-enhanced MO effect.
Fig. 2: Experimental setup and characterization.
Fig. 3: Observation of the conventional Hermitian MO effect and the loss-enhanced MO effect.
Fig. 4: Transmission spectra under different magnetic fields.

Similar content being viewed by others

Data availability

The data that support the plots within this paper are available via figshare at https://doi.org/10.6084/m9.figshare.25998517(ref. 60). All other data used in this study are available from the corresponding authors upon reasonable request.

References

  1. Kimel, A. et al. The 2022 magneto-optics roadmap. J. Phys. D 55, 463003 (2022).

    Article  Google Scholar 

  2. Luo, J. et al. Large effective magnetic fields from chiral phonons in rare-earth halides. Science 382, 698–702 (2023).

    Article  ADS  MATH  Google Scholar 

  3. Yavorsky, M. A. et al. Topological Faraday effect for optical vortices in magnetic films. Phys. Rev. Lett. 130, 166901 (2023).

    Article  ADS  MATH  Google Scholar 

  4. Lyalin, I., Alikhah, S., Berritta, M., Oppeneer, P. M. & Kawakami, R. K. Magneto-optical detection of the orbital Hall effect in chromium. Phys. Rev. Lett. 131, 156702 (2023).

    Article  ADS  Google Scholar 

  5. Dirnberger, F. et al. Magneto-optics in a van der Waals magnet tuned by self-hybridized polaritons. Nature 620, 533–537 (2023).

    Article  ADS  Google Scholar 

  6. Burch, K. S., Mandrus, D. & Park, J.-G. Magnetism in two-dimensional van der Waals materials. Nature 563, 47–52 (2018).

    Article  ADS  Google Scholar 

  7. Choi, Y.-G. et al. Observation of the orbital hall effect in a light metal Ti. Nature 619, 52–56 (2023).

    Article  ADS  MATH  Google Scholar 

  8. Zvezdin, A. K. & Kotov, V. A. Modern Magnetooptics and Magnetooptical Materials (Taylor & Francis, 1997)

  9. Yan, W. et al. Waveguide-integrated high-performance magneto-optical isolators and circulators on silicon nitride platforms. Optica 7, 1555–1562 (2020).

    Article  ADS  MATH  Google Scholar 

  10. Crassee, I. et al. Giant Faraday rotation in single- and multilayer graphene. Nat. Phys. 7, 48–51 (2011).

    Article  Google Scholar 

  11. Chin, J. Y. et al. Nonreciprocal plasmonics enables giant enhancement of thin-film Faraday rotation. Nat. Commun. 4, 1599 (2013).

    Article  ADS  MATH  Google Scholar 

  12. Ignatyeva, D. O. et al. All-dielectric magnetic metasurface for advanced light control in dual polarizations combined with high-Q resonances. Nat. Commun. 11, 5487 (2020).

    Article  ADS  MATH  Google Scholar 

  13. Rizal, C., Shimizu, H. & Mejía-Salazar, J. R. Magneto-optics effects: new trends and future prospects for technological developments. Magnetochemistry 8, 94 (2022).

    Article  Google Scholar 

  14. Rüter, C. E. et al. Observation of parity–time symmetry in optics. Nat. Phys. 6, 192–195 (2010).

    Article  MATH  Google Scholar 

  15. Peng, B. et al. Parity–time-symmetric whispering-gallery microcavities. Nat. Phys. 10, 394–398 (2014).

    Article  MATH  Google Scholar 

  16. Chang, L. et al. Parity–time symmetry and variable optical isolation in active-passive-coupled microresonators. Nat. Photon. 8, 524–529 (2014).

    Article  ADS  MATH  Google Scholar 

  17. Xu, H., Mason, D., Jiang, L. & Harris, J. G. E. Topological energy transfer in an optomechanical system with exceptional points. Nature 537, 80–83 (2016).

    Article  ADS  MATH  Google Scholar 

  18. Chen, H.-Z. et al. Revealing the missing dimension at an exceptional point. Nat. Phys. 16, 571–578 (2020).

    Article  MATH  Google Scholar 

  19. Peng, P. et al. Anti-parity–time symmetry with flying atoms. Nat. Phys. 12, 1139–1145 (2016).

    Article  MATH  Google Scholar 

  20. Li, Y. et al. Anti-parity–time symmetry in diffusive systems. Science 364, 170–173 (2019).

    Article  ADS  MathSciNet  MATH  Google Scholar 

  21. Wu, Y. et al. Observation of parity–time symmetry breaking in a single-spin system. Science 364, 878–880 (2019).

    Article  ADS  MathSciNet  MATH  Google Scholar 

  22. Xiao, L. et al. Non-Hermitian bulk-boundary correspondence in quantum dynamics. Nat. Phys. 16, 761–766 (2020).

    Article  MATH  Google Scholar 

  23. Wang, Y.-T. et al. Experimental investigation of state distinguishability in parity–time symmetric quantum dynamics. Phys. Rev. Lett. 124, 230402 (2020).

    Article  ADS  MATH  Google Scholar 

  24. El-Ganainy, R. et al. Non-Hermitian physics and PT symmetry. Nat. Phys. 14, 11–19 (2018).

    Article  MATH  Google Scholar 

  25. Wang, X.-G., Guo, G.-H. & Berakdar, J. Steering magnonic dynamics and permeability at exceptional points in a parity–time symmetric waveguide. Nat. Commun. 11, 5663 (2020).

    Article  ADS  MATH  Google Scholar 

  26. Yang, Y. et al. Unconventional singularity in anti-parity–time symmetric cavity magnonics. Phys. Rev. Lett. 125, 147202 (2020).

    Article  ADS  Google Scholar 

  27. Zhang, D., Luo, X.-Q., Wang, Y.-P., Li, T.-F. & You, J. Q. Observation of the exceptional point in cavity magnon-polaritons. Nat. Commun. 8, 1368 (2017).

    Article  ADS  MATH  Google Scholar 

  28. Liu, H. et al. Observation of exceptional points in magnonic parity–time symmetry devices. Sci. Adv. 5, 9144 (2019).

    Article  ADS  MATH  Google Scholar 

  29. Liang, C., Tang, Y., Xu, A.-N. & Liu, Y.-C. Observation of exceptional points in thermal atomic ensembles. Phys. Rev. Lett. 130, 263601 (2023).

    Article  ADS  MATH  Google Scholar 

  30. Miri, M.-A. & Alù, A. Exceptional points in optics and photonics. Science 363, 7709 (2019).

    Article  MathSciNet  MATH  Google Scholar 

  31. Chen, W., Özdemir, Ş. K., Zhao, G., Wiersig, J. & Yang, L. Exceptional points enhance sensing in an optical microcavity. Nature 548, 192–196 (2017).

    Article  ADS  Google Scholar 

  32. Hodaei, H. et al. Enhanced sensitivity at higher-order exceptional points. Nature 548, 187–191 (2017).

    Article  ADS  MATH  Google Scholar 

  33. Hokmabadi, M. P., Schumer, A., Christodoulides, D. N. & Khajavikhan, M. Non-Hermitian ring laser gyroscopes with enhanced Sagnac sensitivity. Nature 576, 70–74 (2019).

    Article  ADS  Google Scholar 

  34. Lai, Y.-H., Lu, Y.-K., Suh, M.-G., Yuan, Z. & Vahala, K. Observation of the exceptional-point-enhanced Sagnac effect. Nature 576, 65–69 (2019).

    Article  ADS  MATH  Google Scholar 

  35. Zhang, X., Hu, J. & Zhao, N. Stable atomic magnetometer in parity–time symmetry broken phase. Phys. Rev. Lett. 130, 023201 (2023).

    Article  ADS  MATH  Google Scholar 

  36. Wiersig, J. Enhancing the sensitivity of frequency and energy splitting detection by using exceptional points: Application to microcavity sensors for single-particle detection. Phys. Rev. Lett. 112, 203901 (2014).

    Article  ADS  MATH  Google Scholar 

  37. Peng, B. et al. Loss-induced suppression and revival of lasing. Science 346, 328–332 (2014).

    Article  ADS  MATH  Google Scholar 

  38. Wong, Z. J. et al. Lasing and anti-lasing in a single cavity. Nat. Photon. 10, 796–801 (2016).

    Article  ADS  MATH  Google Scholar 

  39. Huang, X., Lu, C., Liang, C., Tao, H. & Liu, Y.-C. Loss-induced nonreciprocity. Light Sci. Appl. 10, 30 (2021).

    Article  ADS  Google Scholar 

  40. Dong, S. et al. Loss-assisted metasurface at an exceptional point. ACS Photon. 7, 3321–3327 (2020).

    Article  MATH  Google Scholar 

  41. Feng, L. et al. Experimental demonstration of a unidirectional reflectionless parity–time metamaterial at optical frequencies. Nat. Mater. 12, 108–113 (2013).

    Article  ADS  MATH  Google Scholar 

  42. Li, Z. et al. Synergetic positivity of loss and noise in nonlinear non-hermitian resonators. Sci. Adv. 9, 0562 (2023).

    Google Scholar 

  43. Park, J.-H. et al. Symmetry-breaking-induced plasmonic exceptional points and nanoscale sensing. Nat. Phys. 16, 462–468 (2020).

    Article  MATH  Google Scholar 

  44. Wang, H., Lai, Y.-H., Yuan, Z., Suh, M.-G. & Vahala, K. Petermann-factor sensitivity limit near an exceptional point in a Brillouin ring laser gyroscope. Nat. Commun. 11, 1610 (2020).

    Article  ADS  MATH  Google Scholar 

  45. Lau, H.-K. & Clerk, A. A. Fundamental limits and non-reciprocal approaches in non-Hermitian quantum sensing. Nat. Commun. 9, 4320 (2018).

    Article  ADS  MATH  Google Scholar 

  46. Kononchuk, R., Cai, J., Ellis, F., Thevamaran, R. & Kottos, T. Exceptional-point-based accelerometers with enhanced signal-to-noise ratio. Nature 607, 697–702 (2022).

    Article  ADS  Google Scholar 

  47. Ding, W., Wang, X. & Chen, S. Fundamental sensitivity limits for Non-Hermitian quantum sensors. Phys. Rev. Lett. 131, 160801 (2023).

    Article  ADS  MathSciNet  MATH  Google Scholar 

  48. Zhang, M. et al. Quantum noise theory of exceptional point amplifying sensors. Phys. Rev. Lett. 123, 180501 (2019).

    Article  ADS  MATH  Google Scholar 

  49. Jacob, D., Vallet, M., Bretenaker, F., Le Floch, A. & Le Naour, R. Small Faraday rotation measurement with a Fabry–Pérot cavity. Appl. Phys. Lett. 66, 3546–3548 (1995).

    Article  ADS  Google Scholar 

  50. Zak, J., Moog, E. R., Liu, C. & Bader, S. D. Magneto-optics of multilayers with arbitrary magnetization directions. Phys. Rev. B 43, 6423–6429 (1991).

    Article  ADS  MATH  Google Scholar 

  51. Özdemir, Ş. K., Rotter, S., Nori, F. & Yang, L. Parity–time symmetry and exceptional points in photonics. Nat. Mater. 18, 783–798 (2019).

    Article  ADS  MATH  Google Scholar 

  52. Wiersig, J. Response strengths of open systems at exceptional points. Phys. Rev. Res. 4, 023121 (2022).

    Article  MATH  Google Scholar 

  53. Wiersig, J. Distance between exceptional points and diabolic points and its implication for the response strength of non-hermitian systems. Phys. Rev. Res. 4, 033179 (2022).

    Article  MATH  Google Scholar 

  54. Degen, C. L., Reinhard, F. & Cappellaro, P. Quantum sensing. Rev. Mod. Phys. 89, 035002 (2017).

    Article  ADS  MathSciNet  Google Scholar 

  55. Hashemi, A., Busch, K., Christodoulides, D. N., Özdemir, Ş. K. & El-Ganainy, R. Linear response theory of open systems with exceptional points. Nat. Commun. 13, 3281 (2022).

    Article  ADS  MATH  Google Scholar 

  56. Takata, K. et al. Observing exceptional point degeneracy of radiation with electrically pumped photonic crystal coupled-nanocavity lasers. Optica 8, 184–192 (2021).

    Article  ADS  MATH  Google Scholar 

  57. Liang, J. et al. Polariton spin hall effect in a Rashba–Dresselhaus regime at room temperature. Nat. Photon. 18, 357–362 (2024).

    Article  ADS  MATH  Google Scholar 

  58. Opechowski, W. Magneto-optical effects and paramagnetic resonance. Rev. Mod. Phys. 25, 264–268 (1953).

    Article  ADS  MATH  Google Scholar 

  59. Víllora, E. G. et al. Faraday rotator properties of Tb3(Sc1.95Lu0.05)Al3O12, a highly transparent terbium-garnet for visible-infrared optical isolators. Appl. Phys. Lett. 99, 011111 (2011).

    Article  ADS  Google Scholar 

  60. Ruan, Y.-P. et al. Observation of loss-enhanced magneto-optical effect. figshare https://doi.org/10.6084/m9.figshare.25998517 (2024).

Download references

Acknowledgements

This work was supported by the National Natural Science Foundation of China (grant nos. 92365107, 12334012, 12234012, 12305020, 11935006 and 12421005), the National Key R&D Program of China (grant nos. 2019YFA0308700, 2019YFA0308704, 2022YFA1405000, 2021YFA1400900, 2021YFA0718300 and 2024YFE0102400), the Innovation Program for Quantum Science and Technology (grant nos. 2021ZD0301400 and 2021ZD0301500), the Program for Innovative Talents and Teams in Jiangsu (grant no. JSSCTD202138), the Natural Science Foundation of Jiangsu Province, Major Project (grant no. BK20212004), the Hunan Major Sci-Tech Program (grant no. 2023ZJ1010), the China Postdoctoral Science Foundation (grant no. 2023M731613) and Jiangsu Funding Program for Excellent Postdoctoral Talent (grant no. 2023ZB708). C.-W.Q. acknowledges the support from National Research Foundation (grant no. NRF2021-QEP2-03-P09 with WBS number A-8000708-00-00 and grant no. NRF-CRP26-2021-0004).

Author information

Author notes

  1. These authors contributed equally: Ya-Ping Ruan, Jiang-Shan Tang, Zhipeng Li.

Authors and Affiliations

  1. College of Engineering and Applied Sciences, National Laboratory of Solid State Microstructures, Nanjing University, Nanjing, China

    Ya-Ping Ruan, Jiang-Shan Tang, Haodong Wu, Wenpeng Zhou, Longqi Xiao, Shi-Jun Ge, Wei Hu, Yan-Qing Lu & Keyu Xia

  2. Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore

    Zhipeng Li, Jianfeng Chen & Cheng-Wei Qiu

  3. School of Physics, Nanjing University, Nanjing, China

    Han Zhang

  4. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China

    Wuming Liu

  5. Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education, Department of Physics and Synergetic Innovation Center for Quantum Effects and Applications, Hunan Normal University, Changsha, China

    Hui Jing

  6. Institute for Quantum Science and Technology, College of Science, National University of Defense Technology, Changsha, China

    Hui Jing

  7. Hefei National Laboratory, Hefei, China

    Keyu Xia

Authors
  1. Ya-Ping Ruan
    View author publications

    Search author on:PubMed Google Scholar

  2. Jiang-Shan Tang
    View author publications

    Search author on:PubMed Google Scholar

  3. Zhipeng Li
    View author publications

    Search author on:PubMed Google Scholar

  4. Haodong Wu
    View author publications

    Search author on:PubMed Google Scholar

  5. Wenpeng Zhou
    View author publications

    Search author on:PubMed Google Scholar

  6. Longqi Xiao
    View author publications

    Search author on:PubMed Google Scholar

  7. Jianfeng Chen
    View author publications

    Search author on:PubMed Google Scholar

  8. Shi-Jun Ge
    View author publications

    Search author on:PubMed Google Scholar

  9. Wei Hu
    View author publications

    Search author on:PubMed Google Scholar

  10. Han Zhang
    View author publications

    Search author on:PubMed Google Scholar

  11. Cheng-Wei Qiu
    View author publications

    Search author on:PubMed Google Scholar

  12. Wuming Liu
    View author publications

    Search author on:PubMed Google Scholar

  13. Hui Jing
    View author publications

    Search author on:PubMed Google Scholar

  14. Yan-Qing Lu
    View author publications

    Search author on:PubMed Google Scholar

  15. Keyu Xia
    View author publications

    Search author on:PubMed Google Scholar

Contributions

K.X. conceived the original idea and the research, and supervised the project. W.L., H.J., Y.-Q.L. and C.-W.Q. contributed to the idea and co-supervised the project. Y.-P.R. conducted the experiment and performed the data analysis and processing. J.-S.T., Z.L., Y.-P.R., W.L., H.J., C.-W.Q. and K.X. contributed to the theoretical model and interpretation of experimental results. K.X. presented the electric constitutive relation and solely derived the interaction Hamiltonian. H.W., W.Z. and H.Z. contributed to the experimental implementation and details. S.-J.G. and W.H. fabricated the LC cell. J.C., Z.L., Y.-Q.L., W.L., H.J., C.-W.Q. and K.X. developed the underlying physics. Y.-P.R., Z.L., J.C., W.L., H.J., J.-S.T., C.-W.Q. and K.X. contributed to manuscript writing. All authors contributed to discussion of experimental data and results.

Corresponding authors

Correspondence to Cheng-Wei Qiu, Wuming Liu, Hui Jing, Yan-Qing Lu or Keyu Xia.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature Photonics thanks Vladimir Belotelov, Jan Wiersig and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Spherical coordinate system for the magnetization M in the (x, y, z)-coordinate.

The angle φ represents the orientation of M with respect to the z axis, and γ is the angle between M projected on the x-y plane and the x axis50.

Extended Data Fig. 2 Verdet constant of the TGG crystal.

Black dots represent the experimental results and red curve represents the fitting from ref. 59.

Source data

Supplementary information

Supplementary Information

Supplementary Figs. 1–5 and Sections 1–5.

Supplementary Data 1

Source data for supplementary figures.

Source Data Fig. 1

Source data.

Source Data Fig. 2

Source data.

Source Data Fig. 3

Source data.

Source Data Fig. 4

Source data.

Source Data Extended Data Fig. 2

Source data.

Extended data

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ruan, YP., Tang, JS., Li, Z. et al. Observation of loss-enhanced magneto-optical effect. Nat. Photon. 19, 109–115 (2025). https://doi.org/10.1038/s41566-024-01592-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue date:

  • DOI: https://doi.org/10.1038/s41566-024-01592-y

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing