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.

Random anti-lasing through coherent perfect absorption in a disordered medium

Nature volume 567, pages 351–355 (2019)Cite this article

Subjects

Abstract

Non-Hermitian wave engineering is a recent and fast-moving field that examines both fundamental and application-oriented phenomena1,2,3,4,5,6,7. One such phenomenon is coherent perfect absorption8,9,10,11—an effect commonly referred to as ‘anti-lasing’ because it corresponds to the time-reversed process of coherent emission of radiation at the lasing threshold (where all radiation losses are exactly balanced by the optical gain). Coherent perfect absorbers (CPAs) have been experimentally realized in several setups10,11,12,13,14,15,16,17,18, with the notable exception of a CPA in a disordered medium (a medium without engineered structure). Such a ‘random CPA’ would be the time-reverse of a ‘random laser’19,20, in which light is resonantly enhanced by multiple scattering inside a disorder. Because of the complexity of this scattering process, the light field emitted by a random laser is also spatially complex and not focused like a regular laser beam. Realizing a random CPA (or ‘random anti-laser’) is therefore challenging because it requires the equivalent of time-reversing such a light field in all its degrees of freedom to create coherent radiation that is perfectly absorbed when impinging on a disordered medium. Here we use microwave technology to build a random anti-laser and demonstrate its ability to absorb suitably engineered incoming radiation fields with near-perfect efficiency. Because our approach to determining these field patterns is based solely on far-field measurements of the scattering properties of a disordered medium, it could be suitable for other applications in which waves need to be perfectly focused, routed or absorbed.

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

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Learn more

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

Fig. 1: Experimental setup of the random anti-laser.
Fig. 2: Analysis of a CPA state.
Fig. 3: Field and flux patterns of CPA states.
Fig. 4: Transmission of CPA states into the central antenna.

Data availability

The data that support the findings of this study are available from the corresponding authors upon reasonable request.

References

  1. Berry, M. V. Physics of nonhermitian degeneracies. Czech. J. Phys. 54, 1039–1047 (2004).

    Article  ADS  CAS  Google Scholar 

  2. Bender, C. M. Making sense of non-Hermitian Hamiltonians. Rep. Prog. Phys. 70, 947–1018 (2007).

    Article  ADS  MathSciNet  Google Scholar 

  3. Moiseyev, N. Non-Hermitian Quantum Mechanics (Cambridge Univ. Press, Cambridge, 2011).

    Book  Google Scholar 

  4. Heiss, W. D. The physics of exceptional points. J. Phys. A 45, 444016 (2012).

    Article  ADS  MathSciNet  Google Scholar 

  5. Feng, L., El-Ganainy, R. & Ge, L. Non-Hermitian photonics based on parity–time symmetry. Nat. Photon. 11, 752–762 (2017).

    Article  ADS  CAS  Google Scholar 

  6. Longhi, S. Parity-time symmetry meets photonics: a new twist in non-Hermitian optics. Europhys. Lett. 120, 64001 (2017).

    Article  ADS  Google Scholar 

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

    Article  CAS  Google Scholar 

  8. Chong, Y. D., Ge, L., Cao, H. & Stone, A. D. Coherent perfect absorbers: time-reversed lasers. Phys. Rev. Lett. 105, 053901 (2010).

    Article  ADS  CAS  Google Scholar 

  9. Longhi, S. PT-symmetric laser absorber. Phys. Rev. A 82, 031801 (2010).

    Article  ADS  Google Scholar 

  10. Wan, W. et al. Time-reversed lasing and interferometric control of absorption. Science 331, 889–892 (2011).

    Article  ADS  CAS  Google Scholar 

  11. Baranov, D. G., Krasnok, A., Shegai, T., Alù, A. & Chong, Y. Coherent perfect absorbers: linear control of light with light. Nat. Rev. Mater. 2, 17064 (2017).

    Article  ADS  CAS  Google Scholar 

  12. Pu, M. et al. Ultrathin broadband nearly perfect absorber with symmetrical coherent illumination. Opt. Express 20, 2246–2254 (2012).

    Article  ADS  CAS  Google Scholar 

  13. Bruck, R. & Muskens, O. L. Plasmonic nanoantennas as integrated coherent perfect absorbers on SOI waveguides for modulators and all-optical switches. Opt. Express 21, 27652 (2013).

    Article  ADS  Google Scholar 

  14. Sun, Y., Tan, W., Li, H., Li, J. & Chen, H. Experimental demonstration of a coherent perfect absorber with PT phase transition. Phys. Rev. Lett. 112, 143903 (2014).

    Article  ADS  Google Scholar 

  15. Roger, T. et al. Coherent perfect absorption in deeply subwavelength films in the single-photon regime. Nat. Commun. 6, 7031 (2015).

    Article  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  17. Meng, C., Zhang, X., Tang, S. T., Yang, M. & Yang, Z. Acoustic coherent perfect absorbers as sensitive null detectors. Sci. Rep. 7, 43574 (2017).

    Article  ADS  Google Scholar 

  18. Richoux, O., Achilleos, V., Theocharis, G. & Brouzos, I. Subwavelength interferometric control of absorption in three-port acoustic network. Sci. Rep. 8, 12328 (2018).

    Article  ADS  CAS  Google Scholar 

  19. Cao, H. Lasing in random media. Waves Random Media 13, R1–R39 (2003).

    Article  ADS  Google Scholar 

  20. Wiersma, D. S. The physics and applications of random lasers. Nat. Phys. 4, 359–367 (2008).

    Article  CAS  Google Scholar 

  21. Lerosey, G., de Rosny, J., Tourin, A. & Fink, M. Focusing beyond the diffraction limit with far-field time reversal. Science 315, 1120–1122 (2007).

    Article  ADS  CAS  Google Scholar 

  22. Mosk, A. P., Lagendijk, A., Lerosey, G. & Fink, M. Controlling waves in space and time for imaging and focusing in complex media. Nat. Photon. 6, 283–292 (2012).

    Article  ADS  CAS  Google Scholar 

  23. Rotter, S. & Gigan, S. Light fields in complex media: mesoscopic scattering meets wave control. Rev. Mod. Phys. 89, 015005 (2017).

    Article  ADS  Google Scholar 

  24. Kaina, N., Dupré, M., Lerosey, G. & Fink, M. Shaping complex microwave fields in reverberating media with binary tunable metasurfaces. Sci. Rep. 4, 6693 (2015); erratum 5, 7966 (2015).

    Article  Google Scholar 

  25. Ma, G., Fan, X., Sheng, P. & Fink, M. Shaping reverberating sound fields with an actively tunable metasurface. Proc. Natl Acad. Sci. USA 115, 6638–6643 (2018).

    Article  ADS  CAS  Google Scholar 

  26. Gerlach, D. & Paulraj, A. Base station transmitting antenna arrays for multipath environments. Signal Process. 54, 59–73 (1996).

    Article  Google Scholar 

  27. Li, H., Suwunnarat, S., Fleischmann, R., Schanz, H. & Kottos, T. Random matrix theory approach to chaotic coherent perfect absorbers. Phys. Rev. Lett. 118, 044101 (2017).

    Article  ADS  Google Scholar 

  28. Fyodorov, Y. V., Suwunnarat, S. & Kottos, T. Distribution of zeros of the S matrix of chaotic cavities with localized losses and coherent perfect absorption: non-perturbative results. J. Phys. A 50, 30LT01 (2017).

    Article  MathSciNet  Google Scholar 

  29. Chong, Y. D. & Stone, A. D. Hidden black: coherent enhancement of absorption in strongly scattering media. Phys. Rev. Lett. 107, 163901 (2011).

    Article  ADS  CAS  Google Scholar 

  30. Jackson, J. D. Classical electrodynamics (John Wiley & Sons, New York, 2009).

    MATH  Google Scholar 

  31. Cai, M., Painter, O. & Vahala, K. J. Observation of critical coupling in a fiber taper to a silica-microsphere whispering-gallery mode system. Phys. Rev. Lett. 85, 74–77 (2000).

    Article  ADS  CAS  Google Scholar 

  32. Tischler, J. R., Bradley, M. S. & Bulović, V. Critically coupled resonators in vertical geometry using a planar mirror and a 5 nm thick absorbing film. Opt. Lett. 31, 2045–2047 (2006).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

K.P., M.K., A.B., P.A. and S.R. were supported by the Austrian Science Fund (FWF) through project I 1142- N27 (GePartWave). J.B. and U.K. were supported by the French Science Fund (ANR) through project GePartWave and by the European Union via the H2020 project OpenFet NEMF21. The computational results presented here were achieved in part using the Vienna Scientific Cluster (VSC).

Reviewer information

Nature thanks Simon Horsley, Otto Muskens, Riccardo Sapienza and the other anonymous reviewer(s) for their contribution to the peer review of this work.

Author information

Author notes

  1. These authors jointly supervised this work: Ulrich Kuhl, Stefan Rotter.

Authors and Affiliations

  1. Institute for Theoretical Physics, Vienna University of Technology (TU Wien), Vienna, Austria

    Kevin Pichler, Matthias Kühmayer, Andre Brandstötter, Philipp Ambichl & Stefan Rotter

  2. Institut de Physique de Nice, Université Côte d’Azur, CNRS, Nice, France

    Julian Böhm & Ulrich Kuhl

Authors
  1. Kevin Pichler
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Matthias Kühmayer
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Julian Böhm
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Andre Brandstötter
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Philipp Ambichl
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Ulrich Kuhl
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Stefan Rotter
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

Measurements and data evaluation were carried out by K.P. under the supervision of U.K. J.B. and U.K. designed the experimental setup. S.R. proposed the project and supervised the theoretical and numerical tasks carried out by M.K., K.P., A.B. and P.A. K.P. and S.R. wrote the manuscript with input from all authors.

Corresponding authors

Correspondence to Ulrich Kuhl or Stefan Rotter.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

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

Extended data figures and tables

Extended Data Fig. 1 Central antenna coupling.

The plot shows the reflection signal \({\left|R\right|}^{2}\) measured for injection at the central antenna as a function of the signal frequency for different antenna lengths in the disordered configuration with 60 small scatterers shown in Fig. 1. One observes very clearly that at certain frequencies, pronounced minima of the reflection signal, and therefore maxima in the coupling efficiency of the antenna occur. For increasing antenna length these minima become lower until an optimal length is reached that is specific to each minimum (corresponding to ‘critical coupling’). By further increasing the antenna length, the coupling efficiency decreases again. For the minimum in the frequency range around 7.1 GHz (see also main text) the optimal antenna length is 7 mm, whereas in the range around 6.8 GHz a length of 7.5 mm provides the highest coupling efficiency.

Extended Data Fig. 2 Simulated energy-flux distribution in the entire scattering region.

As a complement to Fig. 3, we provide here not only the simulated intensity (top panels) but also the Poynting vector (bottom panels) of the CPA states in the entire scattering region. In the top panels scatterers are displayed as white circles, with the white arrow indicating the position of the absorbing scatterer (that is, the central antenna), whereas in the bottom panels semi-transparent circles mark the scatterers and the filled circle represents the central antenna. For clarity, we plot the Poynting vectors on a different grid of points from that used in the insets in Fig. 3.

Extended Data Fig. 3 Simulated intensity distribution in the presence and absence of the absorbing antenna.

To illustrate the effect of the absorbing scatterer (that is, the central antenna) on the microwave field, we compare the simulated intensity distributions of the CPA states discussed in the main text, injected here in the presence (top panels) and absence (bottom panels) of this absorber (all other parameters and the colour scale stay unchanged). The white arrow indicates the antenna position and white circles represent the scatterers. One can clearly observe that removing the absorbing scatterer causes considerably higher and differently distributed intensity maxima in the waveguide, stemming from additional interference contributions of the waves that are no longer absorbed by the antenna.

Supplementary information

Supplementary Information

This file contains 1) Additional measurement data, 2) Reports on performance checks, 3) More in-depth discussion of results presented in the main text. The file has 14 pages and contains 7 display items in colour.

Rights and permissions

Reprints and Permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Pichler, K., Kühmayer, M., Böhm, J. et al. Random anti-lasing through coherent perfect absorption in a disordered medium. Nature 567, 351–355 (2019). https://doi.org/10.1038/s41586-019-0971-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41586-019-0971-3

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

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