Abstract

We describe the first observation of guided acoustic-wave Brillouin scattering (GAWBS) phase noise in a digital coherent optical fiber transmission. GAWBS noise, which is a forward lightwave generated by thermally excited vibration modes in a cylindrical fiber structure, occurs coherently not only in a signal at a single carrier frequency, but also in modulated wide-band optical signals. Since the signal-to-GAWBS-noise ratio is independent of signal power, it has caused problems in various fields including quantum optics. We point out that GAWBS noise exists even in a digital coherent transmission system such as quadrature amplitude modulation (QAM) and degrades the transmission performance since the phase noise is inevitably included within the bandwidth of the transmitted data. We propose two analogue and one digital method to compensate for the GAWBS noise and demonstrate improved performance in a QAM digital coherent transmission.

© 2018 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

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References

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  1. M. Nakazawa, K. Kikuchi, and T. Miyazaki, eds., High Spectral Density Optical Transmission Technologies (Springer, 2010).
  2. I. P. Kaminow, T. Li, and A. E. Willner, eds., Optical Fiber Telecommunications VIB -Systems and Networks- (Academic, 2013).
  3. S. Beppu, K. Kasai, M. Yoshida, and M. Nakazawa, “2048 QAM (66 Gbit/s) single-carrier coherent optical transmission over 150 km with a potential SE of 15.3 bit/s/Hz,” Opt. Express 23(4), 4960–4969 (2015).
    [Crossref] [PubMed]
  4. J. X. Cai, Y. Sun, H. Zhang, H. G. Batshon, M. V. Mazurczyk, O. V. Sinkin, D. G. Foursa, and A. Pilipetskii, “49.3 Tb/s Transmission Over 9100 km Using C plus L EDFA and 54 Tb/s Transmission Over 9150 km Using Hybrid-Raman EDFA,” J. Lightwave Technol. 33(13), 2724–2734 (2015).
    [Crossref]
  5. T. Mizuno and Y. Miyamoto, “High-capacity dense space division multiplexing transmission,” Opt. Fiber Technol. 35, 108–117 (2017).
    [Crossref]
  6. B. J. Puttnam, R. S. Luıs, E. Agrell, G. Rademacher, J. Sakaguchi, W. Klaus, G. M. Saridis, Y. Awaji, and N. Wada, “High Capacity Transmission Systems Using Homogeneous Multi-Core Fibers,” J. Lightwave Technol. 35(6), 1157–1167 (2017).
    [Crossref]
  7. E. Ip and J. M. Kahn, “Compensation of dispersion and nonlinear impairments using digital backpropagation,” J. Lightwave Technol. 26(20), 3416–3425 (2008).
    [Crossref]
  8. K. Toyoda, Y. Koizumi, T. Omiya, M. Yoshida, T. Hirooka, and M. Nakazawa, “Marked performance improvement of 256 QAM transmission using a digital back-propagation method,” Opt. Express 20(18), 19815–19821 (2012).
    [Crossref] [PubMed]
  9. A. Yariv, D. Fekete, and D. M. Pepper, “Compensation for channel dispersion by nonlinear optical phase conjugation,” Opt. Lett. 4(2), 52–54 (1979).
    [Crossref] [PubMed]
  10. T. Chikama and S. Watanabe, “Cancellation of four-wave mixing in multichannel fibre transmission by midway optical phase conjugation,” Electron. Lett. 30(14), 1156–1157 (1994).
    [Crossref]
  11. J. P. Gordon and L. F. Mollenauer, “Phase noise in photonic communications systems using linear amplifiers,” Opt. Lett. 15(23), 1351–1353 (1990).
    [Crossref] [PubMed]
  12. R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Resolved forward Brillouin scattering in optical fibers,” Phys. Rev. Lett. 54(9), 939–942 (1985).
    [Crossref] [PubMed]
  13. R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Guided acoustic-wave Brillouin scattering,” Phys. Rev. B Condens. Matter 31(8), 5244–5252 (1985).
    [Crossref] [PubMed]
  14. K. Bergman, H. A. Haus, E. P. Ippen, and M. Shirasaki, “Squeezing in a fiber interferometer with a gigahertz pump,” Opt. Lett. 19(4), 290–292 (1994).
    [Crossref] [PubMed]
  15. K. Bergman, H. A. Haus, and M. Shirasaki, “Analysis and measurement of GAWBS spectrum in a nonlinear fiber ring,” Appl. Phys. B 55(3), 242–249 (1992).
    [Crossref]
  16. D. Elser, U. L. Andersen, A. Korn, O. Glöckl, S. Lorenz, Ch. Marquardt, and G. Leuchs, “Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers,” Phys. Rev. Lett. 97(13), 133901 (2006).
    [Crossref] [PubMed]
  17. R. G. Smith, “Optical power handling capacity of low loss optical fibers as determined by stimulated Raman and brillouin scattering,” Appl. Opt. 11(11), 2489–2494 (1972).
    [Crossref] [PubMed]
  18. R. H. Stolen and E. P. Ippen, “Raman gain in glass optical waveguides,” Appl. Phys. Lett. 22(6), 276–278 (1973).
    [Crossref]
  19. E. P. Ippen and R. Stolen, “Stimulated Brillouin scattering in optical fibers,” Appl. Phys. Lett. 21(11), 539–541 (1972).
    [Crossref]
  20. D. Cotter, “Stimulated Brillouin scattering in monomode optical fibre,” J. Opt. Commun. 4(1), 10–19 (1983).
    [Crossref]
  21. D. A. Fishman and J. A. Nagel, “Degradations due to stimulated Brillouin scattering in multigigabit intensity-modulated fiber-optic systems,” J. Lightwave Technol. 11(11), 1721–1728 (1993).
    [Crossref]
  22. N. Yoshizawa and T. Imai, “Stimulated Brillouin scattering suppression by means of applying strain distribution to fiber with cabling,” J. Lightwave Technol. 11(10), 1518–1522 (1993).
    [Crossref]
  23. Y. Wang, K. Kasai, T. Omiya, and M. Nakazawa, “120 Gbit/s, polarization-multiplexed 10 Gsymbol/s, 64 QAM coherent transmission over 150 km using an optical voltage controlled oscillator,” Opt. Express 21(23), 28290–28296 (2013).
    [Crossref] [PubMed]
  24. K. Kasai, M. Yoshida, and M. Nakazawa, “552 Gbit/s, 46 Gbaud, 64 QAM coherent transmission over 160 km with simple LD-based injection-locked homodyne detection,” in European Conference on Optical Communication (ECOC, 2016), W.4.P1.SC5.51.

2017 (2)

2015 (2)

2013 (1)

2012 (1)

2008 (1)

2006 (1)

D. Elser, U. L. Andersen, A. Korn, O. Glöckl, S. Lorenz, Ch. Marquardt, and G. Leuchs, “Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers,” Phys. Rev. Lett. 97(13), 133901 (2006).
[Crossref] [PubMed]

1994 (2)

K. Bergman, H. A. Haus, E. P. Ippen, and M. Shirasaki, “Squeezing in a fiber interferometer with a gigahertz pump,” Opt. Lett. 19(4), 290–292 (1994).
[Crossref] [PubMed]

T. Chikama and S. Watanabe, “Cancellation of four-wave mixing in multichannel fibre transmission by midway optical phase conjugation,” Electron. Lett. 30(14), 1156–1157 (1994).
[Crossref]

1993 (2)

D. A. Fishman and J. A. Nagel, “Degradations due to stimulated Brillouin scattering in multigigabit intensity-modulated fiber-optic systems,” J. Lightwave Technol. 11(11), 1721–1728 (1993).
[Crossref]

N. Yoshizawa and T. Imai, “Stimulated Brillouin scattering suppression by means of applying strain distribution to fiber with cabling,” J. Lightwave Technol. 11(10), 1518–1522 (1993).
[Crossref]

1992 (1)

K. Bergman, H. A. Haus, and M. Shirasaki, “Analysis and measurement of GAWBS spectrum in a nonlinear fiber ring,” Appl. Phys. B 55(3), 242–249 (1992).
[Crossref]

1990 (1)

1985 (2)

R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Resolved forward Brillouin scattering in optical fibers,” Phys. Rev. Lett. 54(9), 939–942 (1985).
[Crossref] [PubMed]

R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Guided acoustic-wave Brillouin scattering,” Phys. Rev. B Condens. Matter 31(8), 5244–5252 (1985).
[Crossref] [PubMed]

1983 (1)

D. Cotter, “Stimulated Brillouin scattering in monomode optical fibre,” J. Opt. Commun. 4(1), 10–19 (1983).
[Crossref]

1979 (1)

1973 (1)

R. H. Stolen and E. P. Ippen, “Raman gain in glass optical waveguides,” Appl. Phys. Lett. 22(6), 276–278 (1973).
[Crossref]

1972 (2)

Agrell, E.

Andersen, U. L.

D. Elser, U. L. Andersen, A. Korn, O. Glöckl, S. Lorenz, Ch. Marquardt, and G. Leuchs, “Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers,” Phys. Rev. Lett. 97(13), 133901 (2006).
[Crossref] [PubMed]

Awaji, Y.

Batshon, H. G.

Bayer, P. W.

R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Resolved forward Brillouin scattering in optical fibers,” Phys. Rev. Lett. 54(9), 939–942 (1985).
[Crossref] [PubMed]

R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Guided acoustic-wave Brillouin scattering,” Phys. Rev. B Condens. Matter 31(8), 5244–5252 (1985).
[Crossref] [PubMed]

Beppu, S.

Bergman, K.

K. Bergman, H. A. Haus, E. P. Ippen, and M. Shirasaki, “Squeezing in a fiber interferometer with a gigahertz pump,” Opt. Lett. 19(4), 290–292 (1994).
[Crossref] [PubMed]

K. Bergman, H. A. Haus, and M. Shirasaki, “Analysis and measurement of GAWBS spectrum in a nonlinear fiber ring,” Appl. Phys. B 55(3), 242–249 (1992).
[Crossref]

Cai, J. X.

Chikama, T.

T. Chikama and S. Watanabe, “Cancellation of four-wave mixing in multichannel fibre transmission by midway optical phase conjugation,” Electron. Lett. 30(14), 1156–1157 (1994).
[Crossref]

Cotter, D.

D. Cotter, “Stimulated Brillouin scattering in monomode optical fibre,” J. Opt. Commun. 4(1), 10–19 (1983).
[Crossref]

Elser, D.

D. Elser, U. L. Andersen, A. Korn, O. Glöckl, S. Lorenz, Ch. Marquardt, and G. Leuchs, “Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers,” Phys. Rev. Lett. 97(13), 133901 (2006).
[Crossref] [PubMed]

Fekete, D.

Fishman, D. A.

D. A. Fishman and J. A. Nagel, “Degradations due to stimulated Brillouin scattering in multigigabit intensity-modulated fiber-optic systems,” J. Lightwave Technol. 11(11), 1721–1728 (1993).
[Crossref]

Foursa, D. G.

Glöckl, O.

D. Elser, U. L. Andersen, A. Korn, O. Glöckl, S. Lorenz, Ch. Marquardt, and G. Leuchs, “Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers,” Phys. Rev. Lett. 97(13), 133901 (2006).
[Crossref] [PubMed]

Gordon, J. P.

Haus, H. A.

K. Bergman, H. A. Haus, E. P. Ippen, and M. Shirasaki, “Squeezing in a fiber interferometer with a gigahertz pump,” Opt. Lett. 19(4), 290–292 (1994).
[Crossref] [PubMed]

K. Bergman, H. A. Haus, and M. Shirasaki, “Analysis and measurement of GAWBS spectrum in a nonlinear fiber ring,” Appl. Phys. B 55(3), 242–249 (1992).
[Crossref]

Hirooka, T.

Imai, T.

N. Yoshizawa and T. Imai, “Stimulated Brillouin scattering suppression by means of applying strain distribution to fiber with cabling,” J. Lightwave Technol. 11(10), 1518–1522 (1993).
[Crossref]

Ip, E.

Ippen, E. P.

K. Bergman, H. A. Haus, E. P. Ippen, and M. Shirasaki, “Squeezing in a fiber interferometer with a gigahertz pump,” Opt. Lett. 19(4), 290–292 (1994).
[Crossref] [PubMed]

R. H. Stolen and E. P. Ippen, “Raman gain in glass optical waveguides,” Appl. Phys. Lett. 22(6), 276–278 (1973).
[Crossref]

E. P. Ippen and R. Stolen, “Stimulated Brillouin scattering in optical fibers,” Appl. Phys. Lett. 21(11), 539–541 (1972).
[Crossref]

Kahn, J. M.

Kasai, K.

Klaus, W.

Koizumi, Y.

Korn, A.

D. Elser, U. L. Andersen, A. Korn, O. Glöckl, S. Lorenz, Ch. Marquardt, and G. Leuchs, “Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers,” Phys. Rev. Lett. 97(13), 133901 (2006).
[Crossref] [PubMed]

Leuchs, G.

D. Elser, U. L. Andersen, A. Korn, O. Glöckl, S. Lorenz, Ch. Marquardt, and G. Leuchs, “Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers,” Phys. Rev. Lett. 97(13), 133901 (2006).
[Crossref] [PubMed]

Levenson, M. D.

R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Guided acoustic-wave Brillouin scattering,” Phys. Rev. B Condens. Matter 31(8), 5244–5252 (1985).
[Crossref] [PubMed]

R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Resolved forward Brillouin scattering in optical fibers,” Phys. Rev. Lett. 54(9), 939–942 (1985).
[Crossref] [PubMed]

Lorenz, S.

D. Elser, U. L. Andersen, A. Korn, O. Glöckl, S. Lorenz, Ch. Marquardt, and G. Leuchs, “Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers,” Phys. Rev. Lett. 97(13), 133901 (2006).
[Crossref] [PubMed]

Luis, R. S.

Marquardt, Ch.

D. Elser, U. L. Andersen, A. Korn, O. Glöckl, S. Lorenz, Ch. Marquardt, and G. Leuchs, “Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers,” Phys. Rev. Lett. 97(13), 133901 (2006).
[Crossref] [PubMed]

Mazurczyk, M. V.

Miyamoto, Y.

T. Mizuno and Y. Miyamoto, “High-capacity dense space division multiplexing transmission,” Opt. Fiber Technol. 35, 108–117 (2017).
[Crossref]

Mizuno, T.

T. Mizuno and Y. Miyamoto, “High-capacity dense space division multiplexing transmission,” Opt. Fiber Technol. 35, 108–117 (2017).
[Crossref]

Mollenauer, L. F.

Nagel, J. A.

D. A. Fishman and J. A. Nagel, “Degradations due to stimulated Brillouin scattering in multigigabit intensity-modulated fiber-optic systems,” J. Lightwave Technol. 11(11), 1721–1728 (1993).
[Crossref]

Nakazawa, M.

Omiya, T.

Pepper, D. M.

Pilipetskii, A.

Puttnam, B. J.

Rademacher, G.

Sakaguchi, J.

Saridis, G. M.

Shelby, R. M.

R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Guided acoustic-wave Brillouin scattering,” Phys. Rev. B Condens. Matter 31(8), 5244–5252 (1985).
[Crossref] [PubMed]

R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Resolved forward Brillouin scattering in optical fibers,” Phys. Rev. Lett. 54(9), 939–942 (1985).
[Crossref] [PubMed]

Shirasaki, M.

K. Bergman, H. A. Haus, E. P. Ippen, and M. Shirasaki, “Squeezing in a fiber interferometer with a gigahertz pump,” Opt. Lett. 19(4), 290–292 (1994).
[Crossref] [PubMed]

K. Bergman, H. A. Haus, and M. Shirasaki, “Analysis and measurement of GAWBS spectrum in a nonlinear fiber ring,” Appl. Phys. B 55(3), 242–249 (1992).
[Crossref]

Sinkin, O. V.

Smith, R. G.

Stolen, R.

E. P. Ippen and R. Stolen, “Stimulated Brillouin scattering in optical fibers,” Appl. Phys. Lett. 21(11), 539–541 (1972).
[Crossref]

Stolen, R. H.

R. H. Stolen and E. P. Ippen, “Raman gain in glass optical waveguides,” Appl. Phys. Lett. 22(6), 276–278 (1973).
[Crossref]

Sun, Y.

Toyoda, K.

Wada, N.

Wang, Y.

Watanabe, S.

T. Chikama and S. Watanabe, “Cancellation of four-wave mixing in multichannel fibre transmission by midway optical phase conjugation,” Electron. Lett. 30(14), 1156–1157 (1994).
[Crossref]

Yariv, A.

Yoshida, M.

Yoshizawa, N.

N. Yoshizawa and T. Imai, “Stimulated Brillouin scattering suppression by means of applying strain distribution to fiber with cabling,” J. Lightwave Technol. 11(10), 1518–1522 (1993).
[Crossref]

Zhang, H.

Appl. Opt. (1)

Appl. Phys. B (1)

K. Bergman, H. A. Haus, and M. Shirasaki, “Analysis and measurement of GAWBS spectrum in a nonlinear fiber ring,” Appl. Phys. B 55(3), 242–249 (1992).
[Crossref]

Appl. Phys. Lett. (2)

R. H. Stolen and E. P. Ippen, “Raman gain in glass optical waveguides,” Appl. Phys. Lett. 22(6), 276–278 (1973).
[Crossref]

E. P. Ippen and R. Stolen, “Stimulated Brillouin scattering in optical fibers,” Appl. Phys. Lett. 21(11), 539–541 (1972).
[Crossref]

Electron. Lett. (1)

T. Chikama and S. Watanabe, “Cancellation of four-wave mixing in multichannel fibre transmission by midway optical phase conjugation,” Electron. Lett. 30(14), 1156–1157 (1994).
[Crossref]

J. Lightwave Technol. (5)

J. Opt. Commun. (1)

D. Cotter, “Stimulated Brillouin scattering in monomode optical fibre,” J. Opt. Commun. 4(1), 10–19 (1983).
[Crossref]

Opt. Express (3)

Opt. Fiber Technol. (1)

T. Mizuno and Y. Miyamoto, “High-capacity dense space division multiplexing transmission,” Opt. Fiber Technol. 35, 108–117 (2017).
[Crossref]

Opt. Lett. (3)

Phys. Rev. B Condens. Matter (1)

R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Guided acoustic-wave Brillouin scattering,” Phys. Rev. B Condens. Matter 31(8), 5244–5252 (1985).
[Crossref] [PubMed]

Phys. Rev. Lett. (2)

R. M. Shelby, M. D. Levenson, and P. W. Bayer, “Resolved forward Brillouin scattering in optical fibers,” Phys. Rev. Lett. 54(9), 939–942 (1985).
[Crossref] [PubMed]

D. Elser, U. L. Andersen, A. Korn, O. Glöckl, S. Lorenz, Ch. Marquardt, and G. Leuchs, “Reduction of guided acoustic wave Brillouin scattering in photonic crystal fibers,” Phys. Rev. Lett. 97(13), 133901 (2006).
[Crossref] [PubMed]

Other (3)

K. Kasai, M. Yoshida, and M. Nakazawa, “552 Gbit/s, 46 Gbaud, 64 QAM coherent transmission over 160 km with simple LD-based injection-locked homodyne detection,” in European Conference on Optical Communication (ECOC, 2016), W.4.P1.SC5.51.

M. Nakazawa, K. Kikuchi, and T. Miyazaki, eds., High Spectral Density Optical Transmission Technologies (Springer, 2010).

I. P. Kaminow, T. Li, and A. E. Willner, eds., Optical Fiber Telecommunications VIB -Systems and Networks- (Academic, 2013).

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Figures (18)

Fig. 1
Fig. 1 Observation of GAWBS noise in a heterodyne coherent optical fiber system. The light source is an ECLD with a linewidth of 4 kHz. The fiber is a standard single-mode fiber (SSMF) with a length of 160 km. The IF beat signal between the signal beam and the local oscillator (LO) beam was set at 1 GHz. EDFA: erbium-doped fiber amplifier, PD: photo detector, RF: radio frequency.
Fig. 2
Fig. 2 Changes in the heterodyne-detected intermediate frequency (IF) frequency spectrum before and after propagation (radio bandwidth (RBW): 100 kHz). (a) Under a back-to-back condition and (b) after 160 km propagation. (c) Radio frequency (RF) spectrum of the propagated light beam obtained with direct detection.
Fig. 3
Fig. 3 Two important GAWBS modes: (a) R01and (b) TR21.
Fig. 4
Fig. 4 Comparison of noise spectra in different fibers (radio bandwidth (RBW): 100 kHz). (a) Comparison of SMF (red) and DSF (blue) and (b) of SMF (red) and SMF + DCF (blue). SMF: single-mode fiber, DSF: dispersion-shifted fiber, and DCF: dispersion compensation fiber. It is clearly seen that the noise frequencies are independent of fiber type.
Fig. 5
Fig. 5 GAWBS noise evolution for fiber lengths in the 5 km to 150 km range (radio bandwidth (RBW): 100 kHz). DSF: dispersion-shifted fiber.
Fig. 6
Fig. 6 GAWBS noise characteristics. (a) Power increase in GAWBS noise spectra as a function of fiber length. Three frequencies of 139.3 MHz (TR2m), 321.2 MHz (R0m), and 464.2 MHz (R0m) are chosen as parameters. (b) Power distribution of GAWBS noise spectra.
Fig. 7
Fig. 7 Reverse phase modulation (RPM) method for GAWBS noise compensation. No QAM modulation was applied to detect pure GAWBS noise. The optical voltage-controlled oscillator (OVCO) was adopted for phase locking between the transmission signal and the local oscillator (LO) ECLD. A grating filter with a 5 GHz bandwidth was used as a narrow band optical filter in the receiver. EDFA: erbium-doped fiber amplifier, PC: polarization controller, SSMF: standard single-mode fiber, PD: photo detector, A/D: analog-to-digital converter, DBM: double balanced mixer, LN: lithium niobate, RF: radio frequency, VCO: voltage controlled oscillator.
Fig. 8
Fig. 8 GAWBS noise compensation with the reverse phase modulation (RPM) method: (a) before compensation and (b) after compensation (radio bandwidth (RBW): 100 kHz).
Fig. 9
Fig. 9 Evaluation of degree of GAWBS noise compensation by using the error vector magnitude (EVM) of a carrier constellation. (a) Constellation under a back-to-back condition, (b) after transmission without phase compensation, and (c) with compensation.
Fig. 10
Fig. 10 Generation of GAWBS noise in a QAM coherent transmission (radio bandwidth (RBW): 100 kHz). The symbol rate of the QAM transmission started from 30 Mbaud, which is narrower than the typical frequency separation of the GAWBS modes of 50 MHz. (a) to (d) correspond to data speeds of 30 Mbaud, 60 Mbaud, 100 Mbaud, and 3 Gbaud, respectively. The absolute center frequency of the IF spectrum is 3 GHz.
Fig. 11
Fig. 11 Experimental setup for 3 Gbaud 64 QAM digital coherent transmission with the reverse phase modulation (RPM) method. The tone signal can be used for both optical voltage controlled oscillator (OVCO) and for detecting the GAWBS phase fluctuation. A grating filter with a 5 GHz bandwidth was used as a narrow band optical filter in the receiver. EDFA: erbium-doped fiber amplifier, PC: polarization controller, OFS: optical frequency shifter, SSMF: standard single-mode fiber, PD: photo detector, B-PD: balanced photo detector, A/D: analog-to-digital converter, DSP: digital signal processor, DBM: double balanced mixer, LN: lithium niobate, RF: radio frequency, VCO: voltage controlled oscillator.
Fig. 12
Fig. 12 Experimental results with the reverse phase modulation (RPM) method. (a) Before GAWBS compensation and (b) after compensation. The error vector magnitude (EVM) was reduced from 2.2% to 1.9%.
Fig. 13
Fig. 13 GAWBS noise compensation using the injection locking (IL) method. A grating filter with a 5 GHz bandwidth was used as a narrow band optical filter in the receiver. EDFA: erbium-doped fiber amplifier, PC: polarization controller, OFS: optical frequency shifter, SSMF: standard single-mode fiber, B-PD: balanced photo detector, A/D: analog-to-digital converter, DSP: digital signal processor, DFB LD: distributed feedback laser diode, LO: local oscillator.
Fig. 14
Fig. 14 Changes in the error vector magnitude (EVM) with the injection locking (IL) method. The constellation is for a 3 Gbaud 64 QAM transmission over 160 km. The EVM without delay tuning was 2.3% and appropriate delay tuning improved the value to 2.0%.
Fig. 15
Fig. 15 Experimental setup for the observation and compensation of GAWBS noise using a digital signal processor. To show the principle of the digital compensation (DC) method, no QAM modulation was applied. Heterodyne detection was used for GAWBS noise detection (IF = 1 GHz). The tone signal was shifted by 10 GHz from the carrier frequency. A grating filter with a 5 GHz bandwidth was used as a narrow band optical filter in the receiver. EDFA: erbium-doped fiber amplifier, PC: polarization controller, OFS: optical frequency shifter, SSMF: standard single-mode fiber, PD: photo detector, A/D: analog-to-digital converter, DSP: digital signal processor, LN: lithium niobate, LO: local oscillator, OVCO: optical voltage controlled oscillator, RF: radio frequency.
Fig. 16
Fig. 16 Experimental results for the compensation of GAWBS noise with the digital compensation (DC) method. (a) and (b) are S1 and S2 after fast Fourier transformation (FFT), respectively, and (c) is the data after GAWBS noise compensation.
Fig. 17
Fig. 17 Experimental setup for GAWBS noise compensation in a 3 Gbaud 64 QAM transmission over 160 km. Homodyne detection was used for the data transmission and heterodyne detection was used for the GAWBS noise detection. A grating filter with a 5 GHz bandwidth was used as a narrow band optical filter in the receiver. EDFA: erbium-doped fiber amplifier, PC: polarization controller, OFS: optical frequency shifter, SSMF: standard single-mode fiber, PD: photo detector, B-PD: balanced photo detector, A/D: analog-to-digital converter, DSP: digital signal processor, DBM: double balanced mixer, LN: lithium niobate, LO: local oscillator, OVCO: optical voltage controlled oscillator, RF: radio frequency.
Fig. 18
Fig. 18 Change in the constellation with the digital compensation (DC) method: (a) before GAWBS compensation and (b) after GAWBS compensation. The error vector magnitude (EVM) in (a) was 2.2%, which was reduced to 1.9% in (b).

Tables (1)

Tables Icon

Table 1 Comparison of experimentally detected noise frequencies in a 125 μm fiber and their theoretical values from ref [12]. (a) R0m mode and (b) TR2m mode.

Equations (3)

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S 1 = e i ω IF1 t e i ϕ G (t)
S 2 = e i ω IF2 t e i ϕ G (t)
S 1 / S 2 = e i( ω IF1 ω IF2 )t

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