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Passively mode-locked laser with an ultra-narrow spectral width

A Corrigendum to this article was published on 01 September 2017

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Most mode-locking techniques introduced in the past1,2 focused mainly on increasing the spectral bandwidth to achieve ultrashort, sub-picosecond-long coherent light pulses. By contrast, less importance seemed to be given to mode-locked lasers generating Fourier-transform-limited nanosecond pulses, which feature the narrow spectral bandwidths required for applications in spectroscopy3, the efficient excitation of molecules4, sensing and quantum optics5. Here, we demonstrate a passively mode-locked laser system that relies on simultaneous nested cavity filtering and cavity-enhanced nonlinear interactions within an integrated microring resonator. This allows us to produce optical pulses in the nanosecond regime (4.3 ns in duration), with an overall spectral bandwidth of 104.9 MHz—more than two orders of magnitude smaller than previous realizations. The very narrow bandwidth of our laser makes it possible to fully characterize its spectral properties in the radiofrequency domain using widely available GHz-bandwidth optoelectronic components. In turn, this characterization reveals the strong coherence of the generated pulse train.

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Figure 1: Experimental set-up of the laser scheme.
Figure 2: Laser characterization.
Figure 3: Beating measurement with a CW laser.
Figure 4: Temperature tuning characteristics of the laser emission frequency.

Change history

  • 01 August 2017

    In the version of this Letter originally published, in the Acknowledgements, the following information was unavailable at the time of publication: "B.E.L. was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, grant no. XDB24030000." This information has now been added in the online versions of the Letter.


  1. Ippen, E. P. Principles of passive mode locking. Appl. Phys. B 58, 159–170 (1994).

    Article  ADS  Google Scholar 

  2. Keller, U. Recent developments in compact ultrafast lasers. Nature 424, 831–838 (2003).

    Article  ADS  Google Scholar 

  3. Mandon, J., Guelachvili, G. & Picque, N. Fourier transform spectroscopy with a laser frequency comb. Nat. Phys. 3, 99–102 (2009).

    Google Scholar 

  4. Wrigge, G., Gerhardt, I., Hwang, J., Zumofen, G. & Sandoghdar, V. Efficient coupling of photons to a single molecule and the observation of its resonance fluorescence. Nat. Phys. 4, 60–66 (2008).

    Article  Google Scholar 

  5. Reimer, C. et al. Generation of multiphoton entangled quantum states by means of integrated frequency combs. Science 351, 1176–1180 (2016).

    Article  ADS  Google Scholar 

  6. McClung, F. J. & Hellwarth, R. W. Giant optical pulsations from ruby. J. Appl. Phys. 33, 828–829 (1962).

    Article  ADS  Google Scholar 

  7. Wolf, E . Progress in Optics (Elsevier, 2004).

    Google Scholar 

  8. Steen, W. & Mazumder, J . Laser Material Processing (Springer, 2010).

    Book  Google Scholar 

  9. Spence, D. E., Kean, P. N. & Sibbett, W. 60-fsec pulse generation from a self-mode-locked Ti sapphire laser. Opt. Lett. 16, 42–44 (1991).

    Article  ADS  Google Scholar 

  10. Matsas, V. J., Newson, T. P., Richardson, D. J. & Payne, D. N. Self-starting passively mode-locked fibre ring soliton laser exploiting nonlinear polarisation rotation. Electron. Lett. 28, 1391–1393 (1992).

    Article  Google Scholar 

  11. Haus, H. A. & Fellow, L. Mode-locking of lasers. IEEE J. Sel. Top. Quantum Electron. 6, 1173–1185 (2000).

    Article  ADS  Google Scholar 

  12. Jones, D. J. et al. Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis. Science 288, 635–639 (2000).

    Article  ADS  Google Scholar 

  13. Sun, Z. et al. A stable, wideband tunable, near transform-limited, graphene-mode-locked, ultrafast laser. Nano Res. 3, 653–660 (2010).

    Article  ADS  Google Scholar 

  14. Kelleher, E. J. R. et al. Nanosecond-pulse fiber lasers mode-locked with nanotubes. Appl. Phys. Lett. 95, 111108 (2010).

    Article  ADS  Google Scholar 

  15. Richardson, D. J., Laming, R. I., Payne, D. N., Matsas, V. & Phillips, M. W. Self-starting passively mode-locked erbium fibre ring laser based on the amplifying Sagnac switch. Electron. Lett. 27, 542–544 (1991).

    Article  Google Scholar 

  16. Udem, T., Reichert, J., Holzwarth, R. & Hänsch, T. W. Absolute optical frequency measurement of the cesium D1 line with a mode-locked laser. Phys. Rev. Lett. 82, 3568–3571 (1999).

    Article  ADS  Google Scholar 

  17. Brabec, T. & Krausz, F. Intense few-cycle laser fields: frontiers of nonlinear optics. Rev. Mod. Phys. 72, 545–591 (2000).

    Article  ADS  Google Scholar 

  18. Fermann, M. E. & Hartl, I. Ultrafast fibre lasers. Nat. Photon. 7, 868–874 (2013).

    Article  ADS  Google Scholar 

  19. Keller, U. et al. Semiconductor saturable absorber mirrors (SESAM's) for femtosecond to nanosecond pulse generation in solid-state lasers. IEEE J. Sel. Top. Quantum Electron. 2, 435–453 (1996).

    Article  ADS  Google Scholar 

  20. Duling, I. N. Subpicosecond all-fibre erbium laser. Electron. Lett. 27, 544–545 (1991).

    Article  Google Scholar 

  21. Zhong, Y. H., Zhang, Z. X. & Tao, X. Y. Passively mode locked fiber laser based on nonlinear optical loop mirror with semiconductor optical amplifier. Laser Phys. 20, 1756–1759 (2010).

    Article  ADS  Google Scholar 

  22. Bolger, B. & Baede, L. Production of 300W, nanosecond, transform limited optical pulses. Opt. Commun. 19, 346–349 (1976).

    Article  ADS  Google Scholar 

  23. Shi, W., Leigh, M. A., Zong, J., Yao, Z. & Nguyen, D. T. High-power all-fiber-based narrow-linewidth single-mode fiber laser pulses in the C-band and frequency conversion to THz generation. IEEE J. Sel. Top. Quantum Electron. 15, 377–384 (2009).

    Article  ADS  Google Scholar 

  24. Nicolaescu, R., Fry, E. S. & Walther, T. Generation of near-Fourier-transform-limited high-energy pulses in a chain of fiber–bulk amplifiers. Opt. Lett. 26, 13–15 (2001).

    Article  ADS  Google Scholar 

  25. Schorstein, K. & Walther, T. A high spectral brightness Fourier-transform limited nanosecond Yb-doped fiber amplifier. Appl. Phys. B 97, 591–597 (2009).

    Article  ADS  Google Scholar 

  26. Wang, H. et al. All-fiber mode-locked nanosecond laser employing intracavity chirped fiber gratings. Opt. Express 18, 4467–4470 (2010).

    Google Scholar 

  27. Xia, H., Li, H., Wang, Z., Chen, Y. & Zhang, X. Nanosecond pulse generation in a graphene mode-locked erbium-doped fiber laser. Opt. Commun. 330, 147–150 (2014).

    Article  ADS  Google Scholar 

  28. Brasch, V. et al. Photonic chip-based optical frequency comb using soliton Cherenkov radiation. Science 351, 357–360 (2016).

    Article  ADS  MathSciNet  Google Scholar 

  29. Moss, D. J., Morandotti, R., Gaeta, A. L. & Lipson, M. New CMOS-compatible platforms based on silicon nitride and Hydex for nonlinear optics. Nat. Photon. 7, 597–607 (2013).

    Article  ADS  Google Scholar 

  30. Grelu, P. & Akhmediev, N. Dissipative solitons for mode-locked lasers. Nat. Photon. 6, 84–92 (2012).

    Article  ADS  Google Scholar 

  31. Stolen, R. H. Optical Kerr effect in glass waveguide. Appl. Phys. Lett. 22, 294–296 (1973).

    Article  ADS  Google Scholar 

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This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) through the Steacie and Discovery Grants Schemes, by the MESI PSR-SIIRI Initiative in Quebec and by the Australian Research Council Discovery Projects scheme. C.R. and P.R. acknowledge the support of NSERC Vanier Canada Graduate Scholarships. M.K. acknowledges funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 656607. B.W. acknowledges the support from the People Programme (Marie Curie Actions) of the European Union's FP7 Programme for INCIPIT under REA grant agreement no. 625466. S.T.C. acknowledges the support from the CityU SRG-Fd programme no. 7004189. R.M. acknowledges support by the NSERC Discovery and Strategic Grant Programs. B.E.L. was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, grant no. XDB24030000. We thank R. Helsten for the design of the temperature controller, J. Azaña for providing some of the required experimental equipment and G. Huyet for useful discussions.

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M.K. and C.R. developed the idea and the experiment. B.E.L. and S.T.C. designed and fabricated the integrated device. C.R., M.K., B.W. and P.R. performed the measurements and analysed the experimental results. E.A.V., T.H. and D.J.M. helped and contributed to scientific discussions. R.M. supervised and managed the project. All authors contributed to the writing of the manuscript.

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Correspondence to Michael Kues or Roberto Morandotti.

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Kues, M., Reimer, C., Wetzel, B. et al. Passively mode-locked laser with an ultra-narrow spectral width. Nature Photon 11, 159–162 (2017).

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