OSA's Digital Library

Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 15, Iss. 15 — Jul. 23, 2007
  • pp: 9731–9736
« Show journal navigation

Tunable self-seeded multiwavelength Brillouin-Erbium fiber laser with enhanced power efficiency

Zuxing Zhang, Li Zhan, and Yuxing Xia  »View Author Affiliations


Optics Express, Vol. 15, Issue 15, pp. 9731-9736 (2007)
http://dx.doi.org/10.1364/OE.15.009731


View Full Text Article

Acrobat PDF (162 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations

Abstract

We have demonstrated a tunable multiwavelength Brillouin-Erbium fiber laser (BEFL), which is internally self-excited without additional Brillouin pump. With the use of a birefringence loop mirror filter, the laser output wavelength can be tuned through modifying the filtering profile of the birefringence filter. As a result, the generation of more than 70-wavelength combs with uniform power distribution has been obtained in ~11-nm tuning range. And the wavelength of combs can be tuned in the bandwidth of the Sagnac loop filter. Also, utilizing the spare port of the 3-dB coupler as the output port, the laser output power efficiency has been enhanced by 13 dB.

© 2007 Optical Society of America

1. Introduction

Multiwavelength fiber lasers, as cost-effective and efficient light sources, have attracted considerable interest due to their applications in test and measurement, optical sensing, and high-capacity wavelength-division-multiplexing (WDM) optical communication systems [1

1. A. Bellemare, M. Karasek, M. Rochette, S. LaRochello, and M. Tetu, “Room temperature multifrequency erbium-doped fiber lasers anchored on the ITU frequency grid,” J. Lightwave Technol. 18, 825–831 (2000). [CrossRef]

]. Many different methods have been proposed to implement stable room-temperature multiwavelength emission of fiber lasers, such as providing frequency-shifted feedback in the cavity to prevent the single mode operation [2

2. K. J. Zhou, D. Y. Zhou, F. Z. Dong, and N. Q. Ngo, “Room-temperature multiwavelength erbium-doped fiber ring laser employing sinusoidal phase-modulation feedback,” Opt. Lett. 28, 893–895 (2003). [CrossRef] [PubMed]

], introducing four-wave mixing in nonlinear fiber to self-stabilize multiwavelength operation [3

3. X. M. Liu and C. Lu, “Self-stabilizing effect of four-wave mixing and its applications on multiwavelength erbium-doped fiber lasers,” IEEE Photon. Technol. Lett. 17, 2541–2543 (2005). [CrossRef]

], incorporating a semiconductor optical amplifier or a Raman amplifier to make use of their inhomogeneous gain characteristics [4

4. H. X. Chen, “Multiwavelength fiber ring lasing by use of a semiconductor optical amplifier,” Opt. Lett. 30, 619–621 (2005). [CrossRef] [PubMed]

, 5

5. Y. G. Han, J. H. Lee, S. H. Kim, and S. B. Lee, “Tunable multi-wavelength Raman fiber laser based on fiber Bragg grating cavity with PMF Lyot-Sagnac filter,” Electron. Lett. 40, 1475–1476, (2004). [CrossRef]

], and using the cascaded stimulated Brillouin scattering (SBS) to introduce nonlinear gain [6

6. G. J. Cowle and D. Y. Stepanov, “Hybrid Brillouin/erbium fiber laser,” Opt. Lett. 21, 1250–1252 (1996). [CrossRef] [PubMed]

13

13. M. P. Fok and C. Shu, “Spacing-adjustable multi-wavelength source from a stimulated Brillouin scattering assisted erbium-doped fiber laser,” Opt. Express 14, 2618–2624 (2006). [CrossRef] [PubMed]

]. Among these, the multiwavelength Brillouin-Erbium fiber laser (BEFL) seems the most attractive for generating multiwavelength because of its simple configuration and its intrinsic properties of rigid frequency spacing and extremely narrow linewidth.

Since Cowle and Stepanov firstly reported the BEFL [6

6. G. J. Cowle and D. Y. Stepanov, “Hybrid Brillouin/erbium fiber laser,” Opt. Lett. 21, 1250–1252 (1996). [CrossRef] [PubMed]

], different kinds of BEFLs have been developed including ring, linear and figure-of-eight cavity configurations [9

9. D. S. Lim, H. K. Lee, K. H. Kim, S. B. Kang, J. T. Ahn, D. I. Chang, and M. Y. Jeon, “Figure-of-eight Brillouin/erbium fibre lasers,” Electron. Lett. 34, 2406–2407 (1998). [CrossRef]

]. As for the tunability of multiwavelength BEFLs, a 12-wavelength comb with 14.5 nm tunable range was obtained by incorporating a Sagnac loop filter into the fiber ring [11

11. Y. J. Song, L. Zhan, S. Hu, Q. H. Ye, and Y. X. Xia, “Tunable multiwavelength Brillouin-erbium fiber laser with a polarization-maintaining fiber Sagnac loop filter,” IEEE Photon. Technol. Lett. 16, 2015–2017 (2004). [CrossRef]

]. A widely tunable multiwavelength BEFL with up to 60 nm tuning range was achieved utilizing a linear cavity through carefully optimizing the Brillouin pump power and the 980 nm pump power [12

12. M. H. Al-Mansoori, M. K. Abd-Rahman, F. R. M. Adikan, and M. A. Mahdi, “Widely tunable linear cavity multiwavelength Brillouin-Erbium fiber lasers,” Opt. Express 13, 3471–3476 (2005). [CrossRef] [PubMed]

]. Their vital inconvenience for practical application is the need of external Brillouin pump, and furthermore the wavelength of the Brillouin pump should been adjusted accordingly in the process of wavelength tuning.

In this paper, a tunable self-seeded multiwavelength BEFL has been demonstrated using a simple cavity configuration. The Brillouin pump is self-excited in the cavity instead of an external one. As a result, the generation of more than 70-wavelength combs with about 11-nm tuning range has been demonstrated through adjusting the reflection profile of the birefringence loop filter incorporated into the laser cavity. Meanwhile, the laser output power efficiency is enhanced by 13 dB through utilizing the spare port of the 3 dB coupler as the output port, and the laser configuration is further simplified.

2. Experimental setup and operation principle

Fig. 1. Schematic diagram of the tunable self-seeded multiwavelength BEFL. The section connected with broken lines is to measure the reflection spectrum of the Sagnac loop mirror.

The configuration of the tunable self-seeded multiwavelength BEFL is shown in Fig. 1. The laser consists of an Erbium-doped fiber amplifier (EDFA), an optical circulator (OC), a length of single mode fiber (SMF) and a birefringence loop mirror filter. The high-birefringence fiber Sagnac loop mirror is composed of a 3-dB coupler, a section of polarization maintaining fiber (PMF) and two polarization controllers (PCs), and its reflection profile can be modified through adjusting the PCs [14

14. X. Fang and R. O. Claus, “Polarization-independent all-fiber wavelength division multiplexer based on a Sagnac interferometer,” Opt. Lett. 20, 2146–2148 (1995). [CrossRef] [PubMed]

, 15

15. N. J. C. Libatique and R. K. Jain, “Broadly tunable wavelength-selectable WDM source using a fiber Sagnac loop filter,” IEEE Photon. Technol. Lett. 13, 1283–1285, (2001). [CrossRef]

]. The port 3 of the OC is connected to the port 1 via an EDFA. The EDFA provides the linear gain. The nonlinear Brillouin gain is generated in the 12.5-km long SMF. The laser output is directly from the spare port of the 3-dB coupler, and measured using an optical spectrum analyzer (OSA) with a spectral resolution of 0.065 nm. To simultaneously measure the reflection spectra of the Sagnac loop mirror in the process of wavelength tuning, a 1×2 optical switch is inserted in the point A in right of the SMF. Broadband light from the amplified spontaneous emission (ASE) source is injected from the port 1 of OC2, and then enter the Sagnac loop mirror through the port 2. The reflected part transits again the port 2 of OC2, finally detected with the OSA from the port 3 of OC2.

The operation principle of the tunable self-seeded BEFL is described as follows. The lasing oscillation is formed in the laser cavity built by the two-port connected OC and the Sagnac loop mirror. The wavelength that experiences the largest net gain acts as the strongest Brillouin pump in the SMF. Due to the bidirectional propagation, once more Rayleigh-backscattered radiation provides feedback, an interferometer consisting of two distributed Rayleigh mirrors is formed in SMF. Although the reflection coefficient of the distributed Rayleigh mirror is very small, the SBS amplification in SMF is great enough to compensate for these low reflections. The feedback caused by the Rayleigh interferometer demonstrates strong spectral selectivity, and can provide primary SBS amplification and lasing for some spectral components inside the SBS line. Thus, the cooperative SBS and Rayleigh processes lead to unusually narrow spectra of the Stokes wave [16

16. Y. J. Song, L. Zhan, J. H. Ji, Y. Su, Q. H. Ye, and Y. X. Xia, “Self-seeded multiwavelength Brillouin-erbium fiber laser,” Opt. Lett. 30, 486–488 (2005). [CrossRef] [PubMed]

, 18

18. A. Fotiadi and R. Kiyan, “Cooperative stimulated Brillouin and Rayleigh backscattering process in optical fiber,” Opt. Lett. 23, 1805–1807 (1998). [CrossRef]

]. Here, the Brillouin pump ωP passes the SMF in both directions. The Brillouin Stokes lines ωB=ωP±Δωω is the Stokes frequency shift) with narrowed linewidth are generated simultaneously. The total gain, which combines the linear gain from EDF and the nonlinear gain from SMF, exhibits an inhomogeneous broadening mechanism. Therefore, the multiwavelength comb can be generated when the Brillouin gain is high enough. The balance between the loss and the gain determines the self-excited Brillouin pump wavelength. It is usually at the peak of the gain. Though adjusting the PCs, we can change the reflection profile of the Sagnac loop mirror. Thus the tunable self-seeded multiwavelength BEFL can be obtained just by adjusting the PCs.

3. Results and discussions

In the experiment, the output power of the EDFA was set at 19 dBm, and a length of 17.2 cm PMF is incorporated into the Sagnac loop mirror. The stable Brillouin multiwavelength comb can be generated under the arbitrary polarization states of two PCs. It is observed that the wavelength of the combs can be tuned in the wavelength range of ~30 nm from ~1546 nm to ~1576 nm. This agrees with the bandwidth of Sagnac loop mirror, which is measured to be 30.1 nm. But in the whole tuning range, the wavelength number is not always unchanged. Figure 2 shows the tuning multiwavelength spectra from 1551.3 nm to 1568.2 nm in our experiment. The combs have the same spacing of 0.088 nm (i.e. 11 GHz). The numbers of the generated Brillouin wavelengths within 6-dB bandwidth are 74, 70, 72, and 70 in Figs. 2(a), 2(b), 2(c), and 2(d), respectively. The tunable range is ~11 nm. The tuning process is continuous and the lasing bandwidth almost keeps a constant. In this range, the generated lines are almost unchanged and the output power of combs is uniform distribution. In order to further understand the role of Sagnac loop mirror, its reflection spectra have been simultaneously measured in the process of wavelength tuning, as shown in Fig. 3. During the measurements, the polarization state of the PCs is fixed corresponding to the same conditions as Figs. 2(a), 2(b), 2(c), and 2(d) respectively, the only need to do is to switch the optical circuit to the side of broadband light source. The results show that the reflection spectra of the Sagnac loop mirror have been tuned ~11.3 nm, which is in agreement with the wavelength tuning range of the multiwavelength comb in Fig. 2.

Fig. 2. Tunable multiwavelength spectra with more than 70 Brillonin wavelengths.
Fig. 3. Reflection spectra of the Sagnac loop corresponding to multiwavelength combs in Fig. 2.

Fig. 4. Multiwavelength spectra with 18 Brillouin wavelengths. (a) Centered at 1546.3 nm, (b) centered at 1575.7 nm.
Fig. 5. Contrast between multiwavelength optical spectra (a) from the 10-dB coupler and (b) from the spare port of the 3-dB coupler.

To verify the operation stability of the tunable self-seeded multiwavelength BEFL, at the same polarization state of the PCs we repeatedly scanned the multiwavelength lasing spectra with 74 Brillouin lines in half-hour span with five-minute spacing. The results, shown in Fig. 5, indicate that the tunable self-seeded multiwavelength BEFL can operate stably on long time scale if no external perturbation is applied to the laser system.

Fig. 6. Repeatedly scanned multiwavelength spectra with 74 Brillouin lines in half-hour span with five-minute spacing.

4. Conclusion

We have demonstrated a tunable self-seeded multiwavelength BEFL. The laser output wavelengths can be tuned through modifying the filtering profile of the birefringence filter. The wavelength of multiwavelength combs can be tuned in the bandwidth of the Sagnac loop filter. Although the number of wavelengths is variable in the whole tunable range due to EDFA gain profile, the generation of more than 70-wavelength combs with uniform output power has been obtained in about 11-nm tunable range. Also, the output power efficiency has been enhanced by 13 dB utilizing the spare port of the 3-dB coupler as the output port.

Acknowledgments

The authors acknowledge the support from National Natural Science Foundation of China under the grants 60577048/10474064/60644006, the Science and Technology Committee of Shanghai Municipal under the contract 04DZ14001, and the Program for New Century Excellent Talents in University of China.

References and links

1.

A. Bellemare, M. Karasek, M. Rochette, S. LaRochello, and M. Tetu, “Room temperature multifrequency erbium-doped fiber lasers anchored on the ITU frequency grid,” J. Lightwave Technol. 18, 825–831 (2000). [CrossRef]

2.

K. J. Zhou, D. Y. Zhou, F. Z. Dong, and N. Q. Ngo, “Room-temperature multiwavelength erbium-doped fiber ring laser employing sinusoidal phase-modulation feedback,” Opt. Lett. 28, 893–895 (2003). [CrossRef] [PubMed]

3.

X. M. Liu and C. Lu, “Self-stabilizing effect of four-wave mixing and its applications on multiwavelength erbium-doped fiber lasers,” IEEE Photon. Technol. Lett. 17, 2541–2543 (2005). [CrossRef]

4.

H. X. Chen, “Multiwavelength fiber ring lasing by use of a semiconductor optical amplifier,” Opt. Lett. 30, 619–621 (2005). [CrossRef] [PubMed]

5.

Y. G. Han, J. H. Lee, S. H. Kim, and S. B. Lee, “Tunable multi-wavelength Raman fiber laser based on fiber Bragg grating cavity with PMF Lyot-Sagnac filter,” Electron. Lett. 40, 1475–1476, (2004). [CrossRef]

6.

G. J. Cowle and D. Y. Stepanov, “Hybrid Brillouin/erbium fiber laser,” Opt. Lett. 21, 1250–1252 (1996). [CrossRef] [PubMed]

7.

G. J. Cowle, D. Y. Stepanov, and Y. T. Chieng, “Brillouin/erbium fiber lasers,” J. Lightwave Technol. 15, 1198–1204 (1997). [CrossRef]

8.

D. S. Lim, H. K. Lee, K. H. Kim, S. B. Kang, J. T. Ahn, and M.Y. Jeon, “Generation of multiorder Stokes and anti-Stokes lines in a Brillouin erbium-fiber laser with a Sagnac loop mirror,” Opt. Lett. 23, 1671–1673 (1998). [CrossRef]

9.

D. S. Lim, H. K. Lee, K. H. Kim, S. B. Kang, J. T. Ahn, D. I. Chang, and M. Y. Jeon, “Figure-of-eight Brillouin/erbium fibre lasers,” Electron. Lett. 34, 2406–2407 (1998). [CrossRef]

10.

M. H. Al-Mansoori, B. Bouzid, B. M. Ali, M. K. Abdullah, and M. A. Mahdi “Multi-wavelength Brillouin-Erbium fibre laser in a linear cavity,” Opt. Commun. 242, 209–214 (2004). [CrossRef]

11.

Y. J. Song, L. Zhan, S. Hu, Q. H. Ye, and Y. X. Xia, “Tunable multiwavelength Brillouin-erbium fiber laser with a polarization-maintaining fiber Sagnac loop filter,” IEEE Photon. Technol. Lett. 16, 2015–2017 (2004). [CrossRef]

12.

M. H. Al-Mansoori, M. K. Abd-Rahman, F. R. M. Adikan, and M. A. Mahdi, “Widely tunable linear cavity multiwavelength Brillouin-Erbium fiber lasers,” Opt. Express 13, 3471–3476 (2005). [CrossRef] [PubMed]

13.

M. P. Fok and C. Shu, “Spacing-adjustable multi-wavelength source from a stimulated Brillouin scattering assisted erbium-doped fiber laser,” Opt. Express 14, 2618–2624 (2006). [CrossRef] [PubMed]

14.

X. Fang and R. O. Claus, “Polarization-independent all-fiber wavelength division multiplexer based on a Sagnac interferometer,” Opt. Lett. 20, 2146–2148 (1995). [CrossRef] [PubMed]

15.

N. J. C. Libatique and R. K. Jain, “Broadly tunable wavelength-selectable WDM source using a fiber Sagnac loop filter,” IEEE Photon. Technol. Lett. 13, 1283–1285, (2001). [CrossRef]

16.

Y. J. Song, L. Zhan, J. H. Ji, Y. Su, Q. H. Ye, and Y. X. Xia, “Self-seeded multiwavelength Brillouin-erbium fiber laser,” Opt. Lett. 30, 486–488 (2005). [CrossRef] [PubMed]

17.

L. Zhan, J. H. Ji, J. Xia, S. Y. Luo, and Y. X. Xia, “160-line multiwavelength generation of linear-cavity self- seeded Brillouin-Erbium fiber laser”, Opt. Express 14, 10233–10238 (2006). [CrossRef] [PubMed]

18.

A. Fotiadi and R. Kiyan, “Cooperative stimulated Brillouin and Rayleigh backscattering process in optical fiber,” Opt. Lett. 23, 1805–1807 (1998). [CrossRef]

OCIS Codes
(060.2320) Fiber optics and optical communications : Fiber optics amplifiers and oscillators
(140.3500) Lasers and laser optics : Lasers, erbium
(290.5900) Scattering : Scattering, stimulated Brillouin

ToC Category:
Fiber Optics and Optical Communications

History
Original Manuscript: March 8, 2007
Revised Manuscript: May 4, 2007
Manuscript Accepted: May 11, 2007
Published: July 19, 2007

Citation
Zuxing Zhang, Li Zhan, and Yuxing Xia, "Tunable self-seeded multiwavelength Brillouin-Erbium fiber laser with enhanced power efficiency," Opt. Express 15, 9731-9736 (2007)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-15-15-9731


Sort:  Author  |  Year  |  Journal  |  Reset  

References

  1. A. Bellemare, M. Karasek, M. Rochette, S. LaRochello, and M. Tetu, "Room temperature multifrequency erbium-doped fiber lasers anchored on the ITU frequency grid," J. Lightwave Technol. 18, 825-831 (2000). [CrossRef]
  2. K. J. Zhou, D. Y. Zhou, F. Z. Dong, and N. Q. Ngo, "Room-temperature multiwavelength erbium-doped fiber ring laser employing sinusoidal phase-modulation feedback," Opt. Lett. 28, 893-895 (2003). [CrossRef] [PubMed]
  3. X. M. Liu and C. Lu, "Self-stabilizing effect of four-wave mixing and its applications on multiwavelength erbium-doped fiber lasers," IEEE Photon. Technol. Lett. 17, 2541-2543 (2005). [CrossRef]
  4. H. X. Chen, "Multiwavelength fiber ring lasing by use of a semiconductor optical amplifier," Opt. Lett. 30, 619-621 (2005). [CrossRef] [PubMed]
  5. Y. G. Han, J. H. Lee, S. H. Kim, and S. B. Lee, "Tunable multi-wavelength Raman fiber laser based on fiber Bragg grating cavity with PMF Lyot-Sagnac filter," Electron. Lett. 40, 1475-1476, (2004). [CrossRef]
  6. G. J. Cowle and D. Y. Stepanov, "Hybrid Brillouin/erbium fiber laser," Opt. Lett. 21, 1250-1252 (1996). [CrossRef] [PubMed]
  7. G. J. Cowle, D. Y. Stepanov, and Y. T. Chieng, "Brillouin/erbium fiber lasers," J. Lightwave Technol. 15, 1198-1204 (1997). [CrossRef]
  8. D. S. Lim, H. K. Lee, K. H. Kim, S. B. Kang, J. T. Ahn, and M.Y. Jeon, "Generation of multiorder Stokes and anti-Stokes lines in a Brillouin erbium-fiber laser with a Sagnac loop mirror," Opt. Lett. 23, 1671-1673 (1998). [CrossRef]
  9. D. S. Lim, H. K. Lee, K. H. Kim, S. B. Kang, J. T. Ahn, D. I. Chang, and M. Y. Jeon, "Figure-of-eight Brillouin/erbium fibre lasers," Electron. Lett. 34, 2406-2407 (1998). [CrossRef]
  10. M. H. Al-Mansoori, B. Bouzid, B. M. Ali, M. K. Abdullah, M. A. Mahdi "Multi-wavelength Brillouin-Erbium fibre laser in a linear cavity," Opt. Commun. 242, 209-214 (2004). [CrossRef]
  11. Y. J. Song, L. Zhan, S. Hu, Q. H. Ye and Y. X. Xia, "Tunable multiwavelength Brillouin-erbium fiber laser with a polarization-maintaining fiber Sagnac loop filter," IEEE Photon. Technol. Lett. 16,2015-2017 (2004). [CrossRef]
  12. M. H. Al-Mansoori, M. K. Abd-Rahman, F. R. M. Adikan, M. A. Mahdi, "Widely tunable linear cavity multiwavelength Brillouin-Erbium fiber lasers," Opt. Express 13, 3471-3476 (2005). [CrossRef] [PubMed]
  13. M. P. Fok and C. Shu, "Spacing-adjustable multi-wavelength source from a stimulated Brillouin scattering assisted erbium-doped fiber laser," Opt. Express 14, 2618-2624 (2006). [CrossRef] [PubMed]
  14. X. Fang and R. O. Claus, "Polarization-independent all-fiber wavelength division multiplexer based on a Sagnac interferometer," Opt. Lett. 20, 2146-2148 (1995). [CrossRef] [PubMed]
  15. N. J. C. Libatique and R. K. Jain, "Broadly tunable wavelength-selectable WDM source using a fiber Sagnac loop filter," IEEE Photon. Technol. Lett. 13, 1283-1285, (2001). [CrossRef]
  16. Y. J. Song, L. Zhan, J. H. Ji, Y. Su, Q. H. Ye, and Y. X. Xia, "Self-seeded multiwavelength Brillouin-erbium fiber laser," Opt. Lett. 30, 486-488 (2005). [CrossRef] [PubMed]
  17. L. Zhan, J. H. Ji, J. Xia, S. Y. Luo, and Y. X. Xia, "160-line multiwavelength generation of linear-cavity self- seeded Brillouin-Erbium fiber laser", Opt. Express 14, 10233-10238 (2006). [CrossRef] [PubMed]
  18. A. Fotiadi and R. Kiyan, "Cooperative stimulated Brillouin and Rayleigh backscattering process in optical fiber," Opt. Lett. 23, 1805-1807 (1998). [CrossRef]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.


« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited