Intense Brillouin amplification in gas using hollow-core waveguides


Among all the nonlinear effects stimulated Brillouin scattering offers the highest gain in solid materials and has demonstrated advanced photonics functionalities in waveguides. The large compressibility of gases suggests that stimulated Brillouin scattering may gain in efficiency with respect to condensed materials. Here, by using a gas-filled hollow-core fibre at high pressure, we achieve a strong Brillouin amplification per unit length, exceeding by six times the gain observed in fibres with a solid silica core. This large amplification benefits from a higher molecular density and a lower acoustic attenuation at higher pressure, combined with a tight light confinement. Using this approach, we demonstrate the capability to perform large optical amplifications in hollow-core waveguides. The implementations of a low-threshold gas Brillouin fibre laser and a high-performance distributed temperature sensor, intrinsically free of strain cross-sensitivity, illustrate the potential for hollow-core fibres, paving the way to their integration into lasing, sensing and signal processing.

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Fig. 1: Principle of the generation of SBS in gas-filled HCFs.
Fig. 2: Experimental gains in gas by SBS.
Fig. 3: Amplification of the probe wave as a function of the pump power in the HCF.
Fig. 4: Gas Brillouin lasing.
Fig. 5: Distributed temperature sensing with no strain cross-sensitivity.
Fig. 6: Experimental Brillouin gain spectra for the HCF filled with different types of gas.

Data availability

The data that support the plots within this paper and other findings of this study are available on Zenodo ( All other data used in this study are available from the corresponding authors upon reasonable request.

Code availability

The simulation code of this study is available on Zenodo (


  1. 1.

    Eggleton, B. J., Poulton, C. G., Rakich, P. T., Steel, M. J. & Bahl, G. Brillouin integrated photonics. Nat. Photon. 13, 664–677 (2019).

    ADS  Google Scholar 

  2. 2.

    Safavi-Naeini, A. H., Thourhout, D. V., Baets, R. & Laer, R. V. Controlling phonons and photons at the wavelength scale: integrated photonics meets integrated phononics. Optica 6, 213–232 (2014).

    ADS  Google Scholar 

  3. 3.

    Wiederhecker, G. S., Dainese, P. & Alegre, T. P. M. Brillouin optomechanics in nanophotonic structures. APL Photon. 4, 071101 (2019).

    ADS  Google Scholar 

  4. 4.

    Kobyakov, A., Sauer, M. & Chowdhury, D. Stimulated Brillouin scattering in optical fibers. Adv. Opt. Photon. 6, 213–232 (2014).

    Google Scholar 

  5. 5.

    Ippen, E. P. & Stolen, R. H. Stimulated Brillouin scattering in optical fibers. Appl. Phys. Lett. 21, 539–541 (1972).

    ADS  Google Scholar 

  6. 6.

    Dainese, P. et al. Stimulated Brillouin scattering from multi-GHz-guided acoustic phonons in nanostructured photonic crystal fibres. Nat. Phys. 2, 388–392 (2006).

    Google Scholar 

  7. 7.

    Kang, M. S., Nazarkin, A., Brenn, A. & Russell, P. S. T. J. Tightly trapped acoustic phonons in photonic crystal fibres as highly nonlinear artificial Raman oscillators. Nat. Phys. 5, 276–280 (2009).

    Google Scholar 

  8. 8.

    Grudinin, I. S., Matsko, A. B. & Maleki, L. Brillouin lasing with a CaF2 whispering gallery mode resonator. Phys. Rev. Lett. 102, 043902 (2009).

    ADS  Google Scholar 

  9. 9.

    Tomes, M. & Carmon, T. Photonic micro-electromechanical systems vibrating at X-band (11-GHz) rates. Phys. Rev. Lett. 102, 113601 (2009).

    ADS  Google Scholar 

  10. 10.

    Lee, H. et al. Chemically etched ultrahigh-Q wedge-resonator on a silicon chip. Nat. Photon. 6, 369–373 (2012).

    ADS  Google Scholar 

  11. 11.

    Pant, R. et al. On-chip stimulated Brillouin scattering. Opt. Express 19, 8285–8290 (2011).

    ADS  Google Scholar 

  12. 12.

    Shin, H. et al. Control of coherent information via on-chip photonic–phononic emitter–receivers. Nat. Commun. 6, 6427 (2015).

    ADS  Google Scholar 

  13. 13.

    Laer, R. V., Kuyken, B., Thourhout, D. V. & Baets, R. Interaction between light and highly confined hypersound in a silicon photonic nanowire. Nat. Photon. 9, 199–203 (2015).

    ADS  Google Scholar 

  14. 14.

    Yang, K. Y. et al. Bridging ultrahigh-Q devices and photonic circuits. Nat. Photon. 12, 297–302 (2018).

    ADS  Google Scholar 

  15. 15.

    Gundavarapu, S. et al. Sub-hertz fundamental linewidth photonic integrated Brillouin laser. Nat. Photon. 13, 60–67 (2019).

    ADS  Google Scholar 

  16. 16.

    Hagenlocker, E. E. & Rado, W. G. Stimulated Brillouin and Raman scattering in gases. Appl. Phys. Lett. 7, 236–238 (1965).

    ADS  Google Scholar 

  17. 17.

    Manteghi, A., Dam, N. J., Meijer, A. S., de Wijin, A. S. & van de Water, W. Spectral narrowing in coherent Rayleigh-Brillouin scattering. Phys. Rev. Lett. 107, 173903 (2011).

    ADS  Google Scholar 

  18. 18.

    Giorgini, A. et al. Stimulated Brillouin cavity optomechanics in liquid droplets. Phys. Rev. Lett. 120, 073902 (2018).

    ADS  Google Scholar 

  19. 19.

    Russell, P. S. T. J., Holzer, P., Chang, W., Abdolvand, A. & Travers, J. C. Hollow-core photonic crystal fibres for gas-based nonlinear optics. Nat. Photon. 8, 278–286 (2014).

    ADS  Google Scholar 

  20. 20.

    Travers, J. C., Chang, W., Nold, J., Joly, N. Y. & Russell, P. S. T. J. Ultrafast nonlinear optics in gas-filled hollow-core photonic crystal fibers. J. Opt. Soc. Am. B 28, A11–A26 (2011).

    Google Scholar 

  21. 21.

    Corkum, P. B., Rolland, C. & Srinivasan-Rao, T. Supercontinuum generation in gases. Phys. Rev. Lett. 57, 2268–2271 (1986).

    ADS  Google Scholar 

  22. 22.

    Popmintchev, T., Chen, M. C., Arpin, P., Murnane, M. M. & Kapteyn, H. C. The attosecond nonlinear optics of bright coherent X-ray generation. Nat. Photon. 4, 822–832 (2010).

    ADS  Google Scholar 

  23. 23.

    Berge, L., Skupin, S., Nuter, R., Kasparian, J. & Wolf, J. P. Ultrashort filaments of light in weakly ionized, optically transparent media. Rep. Prog. Phys. 70, 1633–1713 (2007).

    ADS  Google Scholar 

  24. 24.

    Jasion, G. T. et al. Hollow core NANF with 0.28 dB/km attenuation in the C and L bands. In Optical Fiber Communications Conference Postdeadline Papers 2020 Paper Th4B.4 (OSA, 2020).

  25. 25.

    Dudley, J. M. & Taylor, J. R. Ten years of nonlinear optics in photonic crystal fibre. Nat. Photon. 3, 85–90 (2009).

    ADS  Google Scholar 

  26. 26.

    Benabid, F., Knight, J. C., Antonopoulos, G. & Russell, P. S. T. J. Stimulated Raman scattering in hydrogen-filled hollow-core photonic crystal fiber. Science 298, 399–402 (2002).

    ADS  Google Scholar 

  27. 27.

    Couny, F., Benabid, F., Roberts, P. J., Light, P. S. & Raymer, M. G. Generation and photonic guidance of multi-octave optical-frequency combs. Science 318, 1118–1121 (2007).

    ADS  Google Scholar 

  28. 28.

    Renninger, W. H., Behunin, R. O. & Rakich, P. T. Guided-wave Brillouin scattering in air. Optica 3, 1316–1319 (2016).

    ADS  Google Scholar 

  29. 29.

    Dangui, V., Digonnet, M. J. F. & Kino, G. S. Modeling of the propagation loss and backscattering in air-core photonic-bandgap fibers. J. Light. Technol. 27, 3783–3789 (2009).

    ADS  Google Scholar 

  30. 30.

    Boyd, R. W. Nonlinear Optics 3rd edn (Academic Press, 2008).

  31. 31.

    Bhatia, A. B. Ultrasonic Absorption: An Introduction to the Theory of Sound Absorption and Dispersion in Gases, Liquids and Solids (Oxford University Press, 1967).

  32. 32.

    Landau, L. D. & Lifshitz, E. M. Fluid Mechanics 2nd edn (Pergamon Press, 1987).

  33. 33.

    Floch, S. L. & Cambon, P. Theoretical evaluation of the Brillouin threshold and the steady-state Brillouin equations in standard single-mode optical fibers. J. Opt. Soc. Am. A 20, 1132–1137 (2003).

    ADS  MathSciNet  Google Scholar 

  34. 34.

    Olsson, N. A. & Van Der Ziel, J. P. Characteristics of a semiconductor laser pumped Brillouin amplifier with electronically controlled bandwidth. J. Light. Technol. LT-5, 147–153 (1987).

    ADS  Google Scholar 

  35. 35.

    Li, J., Lee, H., Chen, T. & Vahala, K. J. Characterization of a high coherence, Brillouin microcavity laser on silicon. Opt. Express 20, 20170–20180 (2012).

    ADS  Google Scholar 

  36. 36.

    Danion, G. et al. Mode-hopping suppression in long Brillouin fiber laser with non-resonant pumping. Opt. Lett. 41, 2362–2365 (2016).

    ADS  Google Scholar 

  37. 37.

    Smith, S. P., Zarinetchi, F. & Ezekiel, S. Narrow-linewidth stimulated Brillouin fiber laser and applications. Opt. Lett. 16, 393–395 (1991).

    ADS  Google Scholar 

  38. 38.

    Hartog, A. H. An Introduction to Distributed Optical Fibre Sensors (CRC Press, 2018).

  39. 39.

    Denisov, A., Soto, M. A. & Thévenaz, L. Going beyond 1000000 resolved points in a Brillouin distributed fiber sensor: theoretical analysis and experimental demonstration. Light Sci. Appl. 5, e16074 (2016).

    ADS  Google Scholar 

  40. 40.

    Estrada-Alexanders, A. F. & Trusler, J. P. M. Speed of sound in carbon dioxide at temperatures between (220 and 450) K and pressures up to 14 MPa. J. Chem. Thermodyn. 30, 1589–1601 (1998).

  41. 41.

    Hassan, M. R. A., Yu, F., Wadsworth, W. J. & Knight, J. C. Cavity-based mid-IR fiber gas laser pumped by a diode laser. Optica 3, 218–221 (2016).

    ADS  Google Scholar 

  42. 42.

    Otterstrom, N. T., Behunin, R. O., Kittlaus, E. A., Wang, Z. & Rakich, P. T. A silicon Brillouin laser. Science 360, 1113–1116 (2018).

    ADS  MathSciNet  MATH  Google Scholar 

  43. 43.

    Soto, M. A. & Thévenaz, L. Modeling and evaluating the performance of Brillouin distributed optical fiber sensors. Opt. Express 21, 31347–31366 (2013).

    ADS  Google Scholar 

  44. 44.

    Bykov, D. S., Schmidt, O. A., Euser, T. G. & Russell, P. S. T. J. Flying particle sensors in hollow-core photonic crystal fibre. Nat. Photon. 9, 461–465 (2015).

    ADS  Google Scholar 

  45. 45.

    Couny, F. Photonic Solutions Towards Optical Waveform Synthesis. PhD thesis, University of Bath (2015).

  46. 46.

    Benabid, F., Couny, F., Knight, J. C., Birks, T. A. & Russell, P. S. T. J. Compact, stable and efficient all-fibre gas cells using hollow-core photonic crystal fibres. Nature 434, 488–491 (2005).

    ADS  Google Scholar 

  47. 47.

    Santagiustina, M., Chin, S., Primerov, N., Ursini, L. & Thévenaz, L. All-optical signal processing using dynamic Brillouin gratings. Sci. Rep. 3, 1594 (2013).

    ADS  Google Scholar 

  48. 48.

    Almeida, V. R., Xu, Q., Barrios, C. A. & Lipson, M. Guiding and confining light in void nanostructure. Opt. Lett. 29, 1209–1211 (2004).

    ADS  Google Scholar 

  49. 49.

    Renninger, W. H. et al. Forward Brillouin scattering in hollow-core photonic bandgap fibers. New. J. Phys. 18, 025008 (2016).

    ADS  Google Scholar 

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We acknowledge support from the Swiss National Foundation under grant agreement numbers 178895 and 159897. We thank M. Pang from the Shanghai Institute of Optics and Fine Mechanics for discussions, and F. Yun, S. Sebastian and B. Pickford for the revision of this manuscript.

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L.T. initiated the idea of exploiting SBS in gases through HCFs. F.Y. conceived the ideas of intense Brillouin amplification and Brillouin fibre lasing by using pressurized gas in HCFs. L.T. conceived the strain-insensitive sensing idea. F.Y. and F.G. fabricated the HCF gas cell, designed the measurement set-ups, performed the experiments, simulated the acoustic and optical modes, and theoretically analysed the gain coefficient. F.G. explained the acoustic attenuation in relation to the gas pressure and simulated the impact of strain on the gas-filled HCF. F.Y., F.G. and L.T. wrote the manuscript. L.T. supervised this work.

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Correspondence to Fan Yang or Luc Thévenaz.

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Yang, F., Gyger, F. & Thévenaz, L. Intense Brillouin amplification in gas using hollow-core waveguides. Nat. Photonics 14, 700–708 (2020).

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