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Low-chirp isolator-free 65-GHz-bandwidth directly modulated lasers

Nature Photonics volume 15, pages 59–63 (2021)Cite this article

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Abstract

Today, in the face of ever increasing communication traffic, minimizing power consumption in data communication systems has become a challenge. Direct modulation of lasers, a technique as old as lasers themselves, is known for its high energy efficiency and low cost. However, the modulation bandwidth of directly modulated lasers has fallen behind those of external modulators. In this Article, we report wide bandwidths of 65–75 GHz for three directly modulated laser design implementations, by exploiting three bandwidth enhancement effects: detuned loading, photon–photon resonance and in-cavity frequency modulation–amplitude modulation conversion. Substantial reduction of chirp (α < 1.0) as well as isolator-free operation under a reflection of up to 40% are also realized. A fast data transmission of 294.7 Gb s−1 over 15 km of a standard single-mode fibre in the O-band is demonstrated. This was achieved without an optical fibre amplifier due to a high laser output power of 13.6 dBm.

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Fig. 1: Schematics of three DML designs.
Fig. 2: Simulations.
Fig. 3: Experimental results.
Fig. 4: Experimental results.

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Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

Code availability

An evaluation version of the simulation software LaserMatrix, which can be used to replicate the simulation results in this paper, is available free of charge from R.S. (rschatz@kth.se). The user manual for LaserMatrix is available at https://kth.box.com/s/y5y3i2yhsoe5m97sa8l0enyw1xmvseto.

References

  1. Mardoyan, H. et al. 204-GBaud on–off keying transmitter for inter-data center communications. In Proc. 2018 Optical Fiber Communications Conference and Exhibition Th4A.4 (OSA, 2018).

  2. Verbist, J. et al. First real-time 100-Gb/s NRZ-OOK transmission over 2 km with a silicon photonic electro-absorption modulator. In Proc. 2017 Optical Fiber Communications Conference and Exhibition Th5C.4 (OSA, 2017).

  3. Matsui, Y. et al. 55-GHz bandwidth short-cavity distributed reflector laser and its application to 112-Gb/s PAM-4. In Proc. 2016 Optical Fiber Communications Conference and Exhibition Th5B.4 (OSA, 2016).

  4. Tager, A. A. & Elenkrig, B. B. Stability regimes and high-frequency modulation of laser diodes with short external cavity. IEEE J. Quantum Electron. 29, 2886–2890 (1993).

    Article  ADS  Google Scholar 

  5. Vahala, K. & Yariv, A. Detuned loading in coupled cavity semiconductor lasers—effect on quantum noise and dynamics. Appl. Phys. Lett. 45, 501–503 (1984).

    Article  ADS  Google Scholar 

  6. Matsui, Y. in Datacenter Connectivity Technologies: Principles and Practice (ed. Chang, F.) Ch. 3 (River Publishers, 2018).

  7. Kjebon, O. et al. 30 GHz direct modulation bandwidth in detuned loaded InGaAsP DBR laser at 1.55-μm wavelength. Electron. Lett 33, 488–489 (1997).

    Article  ADS  Google Scholar 

  8. Yamaoka, S. et al. 239.3-Gbit/s net rate PAM-4 transmission using directly modulated membrane lasers on high-thermal-conductivity SiC. In Proc. 45th European Conference on Optical Communication (ECOC’19) PD.2.1 (OSA, 2019).

  9. Che, D. et al. Direct modulation of a 54-GHz distributed Bragg reflector laser with 100-GBaud PAM-4 and 80-GBaud PAM-8. In Proc. 2020 Optical Fiber Communications Conference and Exhibition Th3C.1 (OSA, 2020).

  10. Matsui, Y. et al. 28-Gbaud PAM4 and 56-Gb/s NRZ performance comparison using 1,310-nm Al-BH DFB laser. IEEE J. Lightwave Technol. 34, 2677–2683 (2016).

    Article  ADS  Google Scholar 

  11. Troppenz, U. et al. 40 Gbit/s directly modulated lasers: physics and application. Proc. SPIE 7953, 79530F (2011).

    Article  Google Scholar 

  12. Liu, Z. et al. 50-GHz repetition gain switching using a cavity-enhanced DFB laser assisted by optical injection locking. IEEE J. Lightwave Technol. 38, 1844–1850 (2020).

    Article  ADS  Google Scholar 

  13. Chacinski, M. & Schatz, R. Impact of losses in the Bragg section on the dynamics of detuned loaded DBR lasers. IEEE J. Quantum Electron. 46, 1360–1367 (2010).

    Article  ADS  Google Scholar 

  14. Huang, H. et al. Analysis of the optical feedback dynamics in InAs/GaAs quantum dot lasers directly grown on silicon. J. Opt. Soc. Am. B 35, 2780–2787 (2018).

    Article  ADS  Google Scholar 

  15. Matsuda, M. et al. Low-noise characteristics on 1.3-μm-wavelength quantum-dot DFB lasers under external optical feedback. In 26th IEEE International Semiconductor Laser Conference (ISCL) TuD5 (IEEE, 2018).

  16. Petermann, K. Laser Diode Modulation and Noise (Kluwer Academic Publishers, 1988).

  17. Helms, J. & Petermann, K. A simple analytic expression for the stable operation range of laser diodes with optical feedback. IEEE J. Quantum Electron. 26, 833–836 (1990).

    Article  ADS  Google Scholar 

  18. Nilsson, O. & Buus, J. Linewidth and feedback sensitivity of semiconductor diode lasers. IEEE J. Quantum Electron. 26, 2039–2042 (1990).

    Article  ADS  Google Scholar 

  19. Watanabe, T., Yasaka, H., Sakaida, N. & Koga, M. Waveform shaping of chirp-controlled signal by semiconductor optical amplifier using Mach–Zehnder frequency discriminator. IEEE Photon. Technol. Lett. 10, 1422–1424 (1999).

    Article  ADS  Google Scholar 

  20. Matsui, Y. Directly modulated laser for PON applications. US patent 20,130,308,959 A1 (2013).

  21. Che, D. & Shieh, W. Squeezing out the last few bits from band-limited channels with entropy loading. Opt. Express 27, 9321–9329 (2019).

    Article  ADS  Google Scholar 

  22. Shindo, T. et al. Demonstration of 1.3-μm wavelength range super structure grating DBR laser with wide wavelength tuning range of over 30 nm by introducing carrier confinement layers. Proc. SPIE 11301, 113010S (2020).

    Google Scholar 

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Acknowledgements

We thank A. Verma, G. Carey, Y.-L. Ha, J. Wu and B. Young at II-VI Inc. for growth and device fabrication; T. Phan, M. Steib and R. Rhodes at II-VI Inc. for supporting experiments; S. Chandrasekhar, J. Cho, X. Chen and P. Winzer at Nokia Bell Labs for supporting the project; Z. Liu at University College London and R. Kaiser at Fraunhofer Heinrich-Hertz-Institut for fruitful discussions; E. Sokolov and N. Andre at VPIphotonics for support in large-signal simulations.

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Authors and Affiliations

  1. II-VI Incorporated, Fremont, CA, USA

    Yasuhiro Matsui, Ferdous Khan, Martin Kwakernaak & Tsurugi Sudo

  2. KTH Royal Institute of Technology, Applied Physics, Photonics, Stockholm, Sweden

    Richard Schatz

  3. Nokia Bell Labs, Holmdel, NJ, USA

    Di Che

Authors
  1. Yasuhiro Matsui
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  2. Richard Schatz
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  3. Di Che
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  4. Ferdous Khan
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  5. Martin Kwakernaak
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  6. Tsurugi Sudo
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Contributions

Y.M. proposed the idea and is the main lead of the project. R.S. developed the simulation program and discussed the physics. D.C. performed transmission experiments and F.K. processed the devices. M.K. and T.S. supervised the project.

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Correspondence to Yasuhiro Matsui.

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The authors declare no competing interests.

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Peer review information Nature Photonics thanks Ute Troppenz and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Information

Supplementary Figs. 1–3 and discussions.

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Matsui, Y., Schatz, R., Che, D. et al. Low-chirp isolator-free 65-GHz-bandwidth directly modulated lasers. Nat. Photonics 15, 59–63 (2021). https://doi.org/10.1038/s41566-020-00742-2

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