한국광학회지 (Korean Journal of Optics and Photonics)

  • 제32권3호
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  • Pages.120-125
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  • 2021
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  • 1225-6285(pISSN)
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  • 2287-321X(eISSN)
한국광학회 (Optical Society of Korea)
권호 표지
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선편광된 10 GHz 선폭의 1 kW급 20/400-㎛ 이터븀 첨가 광섬유 레이저

Linearly Polarized 1-kW 20/400-㎛ Yb-doped Fiber Laser with 10-GHz Linewidth

  • 정예지 ((주)한화 종합연구소 레이저개발2팀) ;
  • 정민완 ((주)한화 종합연구소 레이저개발2팀) ;
  • 이강인 ((주)한화 종합연구소 레이저개발2팀) ;
  • 김태우 ((주)한화 종합연구소 레이저개발2팀) ;
  • 김재인 ((주)한화 종합연구소 레이저개발2팀) ;
  • 이용수 ((주)한화 종합연구소 레이저개발2팀) ;
  • 조준용 ((주)한화 종합연구소 레이저개발2팀)
  • Jung, Yeji (Laser and Sensor Systems Team, Defense R&D Center, Hanwha Co.) ;
  • Jung, Minwan (Laser and Sensor Systems Team, Defense R&D Center, Hanwha Co.) ;
  • Lee, Kangin (Laser and Sensor Systems Team, Defense R&D Center, Hanwha Co.) ;
  • Kim, Taewoo (Laser and Sensor Systems Team, Defense R&D Center, Hanwha Co.) ;
  • Kim, Jae-Ihn (Laser and Sensor Systems Team, Defense R&D Center, Hanwha Co.) ;
  • Lee, Yongsoo (Laser and Sensor Systems Team, Defense R&D Center, Hanwha Co.) ;
  • Cho, Joonyong (Laser and Sensor Systems Team, Defense R&D Center, Hanwha Co.)
  • 투고 : 2020.12.09
  • 심사 : 2021.04.05
  • 발행 : 2021.06.25
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초록

본 연구에서는 다파장 빔결합을 위한 master oscillator power amplifier (MOPA) 구조의 선편광 고출력 이터븀 첨가 광섬유 레이저를 개발하였다. 유도 브릴루앙 산란(stimulated Brillouin scattering, SBS)을 억제하기 위하여 pseudo-random binary sequence (PRBS) 신호로 위상 변조 및 비트길이를 최적화한 선폭 약 10 GHz의 시드 레이저를 구현하였으며, 이를 이용하여 3단 증폭을 하였다. 주 증폭단에서는 모드 불안정성 현상(mode instability, MI)의 문턱값을 높이기 위하여 코어 및 클래딩의 직경이 각각 20 ㎛, 40 ㎛인 편광유지(polarization maintaining, PM) 이터븀 첨가 광섬유를 이용하고 지름이 약 9-12 cm인 나선형 홈에 적용하였다. 그 결과, 입사된 여기광 대비 기울기 효율이 83.7%인 1.004 kW의 레이저 출력을 얻었다. 또한, 빔품질(M2)과 편광소광율(polarization extinction ratio, PER)은 각각 1.12와 21.5 dB로 측정되었다. 더욱이, 역방향 스펙트럼의 레일리 신호와 SBS 신호의 첨두 세기 비율은 2.36 dB로 관측되어, SBS가 완화된 레이저 구현을 확인하였다. 또한 증폭 출력에 따라 기울기 효율 및 빔품질의 저하가 없어 모드불안정이 발생하지 않음을 확인하였다.

We have developed a linearly polarized high-power Yb-doped fiber laser in the master oscillator power amplifier (MOPA) scheme for efficient spectral beam combining. We modulated the phase of the seed laser by pseudo-random binary sequence (PRBS), with the bit length optimized to suppress stimulated Brillouin scattering (SBS), and subsequently amplified seed power in a 3-stage amplifier system. We have constructed by coiling the polarization-maintaining (PM) Yb-doped fiber, with core and cladding diameters of 20 ㎛ and 400 ㎛ respectively, to a diameter of 9-12 cm for suppression of the mode instability (MI). Finally, we obtained an output power of 1.004 kW with a slope efficiency of 83.7% in the main amplification stage. The beam quality factor M2 and the polarization extinction ratio (PER) were measured to be 1.12 and 21.5 dB respectively. Furthermore, the peak-intensity difference between the Rayleigh signal and SBS signal was observed to be 2.36 dB in the backward spectra, indicating that SBS is successfully suppressed. In addition, it can be expected that the MI does not occur because not only there is no decrease in slope efficiency, but also the beam quality for each amplified output is maintained.

키워드

참고문헌

  1. D. J. Richardson, J. Nilsson, and W. A. Clarkson, "High power fiber lasers: current status and future perspectives," J. Opt. Soc. Am. B 27, B63-B92 (2010). https://doi.org/10.1364/JOSAB.27.000B63
  2. C. Jauregui, J. Limpert, and A. Tunnermann, "High-power fibre lasers," Nat. Photonics 7, 861-867 (2013). https://doi.org/10.1038/nphoton.2013.273
  3. M. N. Zervas and C. A. Codemard, "High power fiber lasers: a review," IEEE J. Sel. Top. Quantum Electron. 20, 219-241 (2014). https://doi.org/10.1109/JSTQE.2014.2321279
  4. Q. Fang, J. H. Li, W. Shi, Y. G. Qin, Y. Xu, X. J. Meng, R. A. Norwood, and N. Peyghambarian, "5 kW near-diffractionlimited and 8 kW high-brightness monolithic continuous wave fiber lasers directly pumped by laser diodes," IEEE Photonics J. 9, 1506107 (2017).
  5. S. Ikoma, H. K. Nguyen, M. Kashiwagi, K. Uchiyama, K. Shima, and D. Tanaka, "3 kW single stage all-fiber Yb-doped single-mode fiber laser for highly reflective and highly thermal conductive materials processing," Proc. SPIE 10083, 100830Y (2017).
  6. F. Moller, R. G. Kramer, C. Matzdorf, S. Nolte, M. Strecker, F. Stutzki, M. Plotner, V. Bock, T. Schreiber, and A. Tunnermann, "Comparison between bidirectional pumped Yb-doped all-fiber single-mode amplifier and oscillator setup up to a power level of 5 kW," in Advanced Solid State Lasers (Optical Society of America, 2018), paper AM2A.3.
  7. J. Lee, K. H. Lee, H. Jeong, M. Park, J. H. Seung, and J. H. Lee, "2.05 kW all-fiber high-beam-quality fiber amplifier with stimulated Brillouin scattering suppression incorporating a narrow-linewidth fiber-bragg-grating-stabilized laser diode seed source," Appl. Opt. 58, 6251-6256 (2019). https://doi.org/10.1364/AO.58.006251
  8. B. Shiner, "The impact of fiber laser technology on the world wide material processing market," in CLEO: Applications and Technology (Optical Society of America, 2013), paper AF2J.1.
  9. T. Y. Fan, "Laser beam combining for high-power, high-radiance sources," IEEE J. Sel. Top. Quantum Electron. 11, 567-577 (2005). https://doi.org/10.1109/JSTQE.2005.850241
  10. S. J. Augst, J. K. Ranka, T. Y. Fan, and A. Sanchez, "Beam combining of ytterbium fiber amplifiers," J. Opt. Soc. Am. B 24, 1707-1715 (2007). https://doi.org/10.1364/JOSAB.24.001707
  11. C. C. Cook and T. Y. Fan, "Spectral beam combining of Yb-doped fiber lasers in an external cavity," Advanced Solid State Lasers (Optical Society of America, 1999), paper PD5.
  12. V. Khitrov, K. Farley, R. Leveille, J. Galipeau, I. Majid, S. Christensen, B. Samson, and K. Tankala, "kW level narrow linewidth Yb fiber amplifiers for beam combining," Proc. SPIE 7686, 76860A (2010).
  13. C. Wirth, O. Schmidt, I. Tsybin, T. Schreiber, R. Eberhardt, J. Limpert, A. Tunnermann, K. Ludewigt, M. Gowin, E. ten Have, and M. Jung, "High average power spectral beam combining of four fiber amplifiers to 8.2 kW," Opt. Lett. 36, 3118-3120 (2011). https://doi.org/10.1364/OL.36.003118
  14. E. Honea, R. S. Afzal, M. Savage-Leuchs, J. Henrie, K. Brar, N. Kurz, D. Jander, N. Gitkind, D. Hu, C. Robin, A. M. Jones, R. Kasinadhuni, and R. Humphreys, "Advances in fiber laser spectral beam combining for power scaling," Proc. SPIE 9730, 97300Y (2016).
  15. Y. Kwon, K. Park, D. Lee, H. Chang, S. Lee, L. A. Vazquez-Zuniga, Y. S. Lee, D. H. Kim, H. T. Kim, and Y. Jeong, "Current status and prospects of high-power fiber laser technology," Korean J. Opt. Photon. 27, 1-17 (2016). https://doi.org/10.3807/KJOP.2016.27.1.001
  16. T. J. Wagner, "Fiber laser beam combining and power scaling progress: air force research laboratory laser division," Proc. SPIE 8237, 823718 (2012).
  17. J. D. Hansryd, F. Dross, M. Westlund, P. A. Andrekson, and S. N. Knudsen, "Increase of the SBS threshold in a short highly nonlinear fiber by applying a temperature distribution," J. Light. Tech. 19, 1691-1697 (2001). https://doi.org/10.1109/50.964069
  18. J. M. C. Boggio, J. D. Marconi, and H. L. Fragnito, "Experimental and numerical investigation of the SBS-threshold increase in an optical fiber by applying strain distributions," J. Light. Technol. 23, 3808-3814 (2005). https://doi.org/10.1109/JLT.2005.856226
  19. Y. Liu, Z. Lv, Y. Dong, and Q. Li, "Research on stimulated Brillouin scattering suppression based on multifrequency phase modulation," Chin. Opt. Lett. 7, 29-31 (2009). https://doi.org/10.3788/COL20090701.0029
  20. S. Jeong, K. Kim, S. Lee, S. Hwang, H. Yang, B. Moon, Y. M. Jhon, M. K. Park, and J. H. Lee, "Characteristics of stimulated Brillouin scattering suppression in high-power fiber lasers using temperature gradients," Korean J. Opt. Photon. 30, 167-173 (2019). https://doi.org/10.3807/KJOP.2019.30.4.167
  21. V. Balaswamy, R. Prakash, V. Choudhury, S. Aparanji, B. S. Vikram, and V. R. Supradeepa, "Experimental analysis of stimulated Brillouin enhancement in high power, line-broadened, narrow-linewidth fiber amplifiers due to spectral overlap between the Brillouin gain spectrum and the signal back-scatter from the fiber termination," Proc. SPIE 10902, 109021G (2019).
  22. B. Ward, C. Robin, and I. Dajani, "Origin of thermal modal instabilities in large mode area fiber amplifiers," Opt. Express 20, 11407-11422 (2012). https://doi.org/10.1364/OE.20.011407
  23. R. Tao, P. Ma, X. Wang, P. Zhou, and Z. Liu, "Study of wavelength dependence of mode instability based on a semi-analytical model," IEEE J. Quantum Electron. 51, 1600106 (2015).
  24. M. N. Zervas, "Transverse mode instability analysis in fiber amplifiers," Proc. SPIE 10083, 100830M (2017).
  25. R. Su, R. Tao, X. Wang, H. Zhang, P. Ma, P. Zhou, and X. Xu, "2.43 kW narrow linewidth linearly polarized all-fiber amplifier based on mode instability suppression," Laser Phys. Lett. 14, 085102 (2017). https://doi.org/10.1088/1612-202X/aa760b
  26. I. Dajani, C. Zeringue, and T. Shay, "Investigation of nonlinear effects in multitone-driven narrow linewidth high-power amplifiers," IEEE J. Sel. Top. Quantum Electron. 15, 406-414 (2009). https://doi.org/10.1109/JSTQE.2008.2011497
  27. I. Dajani, C. Zeringue, C. Lu, C. Vergien, L. Henry, and C. Robin, "Stimulated Brillouin scattering suppression through laser gain competition: scalability to high power," Opt. Lett. 35, 3114-3116 (2010). https://doi.org/10.1364/OL.35.003114
  28. A. Flores, C. Robin, A. Lanari, and I. Dajani, "Pseudo-random binary sequence phase modulation for narrow linewidth, kilowatt, monolithic fiber amplifiers," Opt. Express 22, 17735-17744 (2014). https://doi.org/10.1364/OE.22.017735
  29. E. C. Honea, M. P. Savage-Leuchs, S. M. Courtney, K. S. Brar, J. D. Henrie, and C. D. Dilley, "Fiber amplifier system for suppression on modal instabilities and method," US Patent US9214781B2 (2015).
  30. S. Jeong, K. Kim, T. Kim, S. Lee, H. Yang, J. Lee, K. H. Lee, J. H. Lee, and M. Jo, "All-fiber 1.5-kW-class single-mode Ybdoped polarization-maintaining fiber laser with 10 GHz line-width," Korean J. Opt. Photon. 31, 223-230 (2020). https://doi.org/10.3807/KJOP.2020.31.5.223
  31. M. Liu, Y. Yang, H. Shen, J. Zhang, X. Zou, H. Wang, L. Yuan, Y. You, G. Bai, B. He, and J. Zhou, "1.27 kW, 2.2 GHz pseudorandom binary sequence phase modulated fiber amplifier with Brillouin gain-spectrum overlap," Sci. Rep. 10, 629 (2020). https://doi.org/10.1038/s41598-019-57408-5
  32. N. Platonov, R. Yagodkin, J. De La Cruz, A. Yusim, and V. Gapontsev, "Up to 2.5-kW on non-PM fiber and 2.0-kW linear polarized on PM fiber narrow linewidth CW diffraction-limited fiber amplifiers in all-fiber format," Proc. SPIE 10512, 105120E (2018).