Manipulation of operation states by polarization control in an erbium-doped fiber laser with a hybrid saturable absorber Kuei-Huei Lin 1 , Jung-Jui Kang 2 , Hsiao-Hua Wu 3 , Chao-Kuei Lee 2 , and Gong-Ru Lin 4 1 Department of Science, Taipei Municipal University of Education 1, Ai-Kuo West Rd., Taipei 100, Taiwan 2 Department of Photonics, National Sun Yat-Sen University 70, Lien-Hai Rd.,Kaohsiung 804, Taiwan 3 Department of Physics, Tunghai University 181, Sec. 3 Chung Kang Rd., Taichung 40704, Taiwan hhwu@thu.edu.tw 4 Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University, 1, Roosevelt Rd. Sec. 4, Taipei 10617, Taiwan grlin@ntu.edu.tw Abstract: We propose an operation switchable ring-cavity erbium-doped fiber laser (EDFL) via intra-cavity polarization control. By using a semiconductor saturable absorber mirror in the EDFL cavity, stable Q-switching, Q-switched mode-locking, continuous-wave mode-locking, pulse splitting, and harmonic mode-locking pulses can be manipulated simply by detuning a polarization controller while keeping the pump power at the same level. All EDFL operation states can be obtained under the polarization angles detuning within 180°. Continuous-wave mode-locking of EDFL with 800-fs pulsewidth repeated at 4 MHz has been obtained, for which the output pulse energy is 0.5 nJ and the peak power is 625 W. Interaction between solitons and the accompanied non-soliton component will lead to either pulse splitting or 5 th -order harmonic mode-locking at repetition rate of 20 MHz. 2009 Optical Society of America OCIS codes: (140.3510) Lasers, fiber; (140.3540) Lasers, Q-switched; (140.4050) Mode-locked lasers; (190.5970) Semiconductor nonlinear optics including MQW References and links 1. V. N. Filippov, A. N. Starodumov, and A. V. Kir’yanov, “All-fiber passively Q-switched low-threshold erbium laser,” Opt. Lett. 26, 343-345 (2001). 2. Y. Zhao and S. D. Jackson, “Passively Q-switched fiber laser that uses saturable Raman gain,” Opt. Lett. 31, 751-753 (2006). 3. T. Hakulinen and O. G. Okhotnikov, “8 ns fiber laser Q switched by the resonant saturable absorber mirror,” Opt. Lett. 32, 2677-2679 (2007). 4. B. C. Barnett, L. Rahman, M. N. Islam, Y. C. Chen, P. Bhattacharya, W. Riha, K. V. Reddy, A. T. Howe, K. A. Stair, H. Iwamura, S. R. Friberg, and T. Mukai, “High-power erbium-doped fiber laser mode locked by a semiconductor saturable absorber,” Opt. Lett. 20, 471-473 (1995). 5. O. Okhotnikov, A. Grudinin, and M. Pessa, “Ultra-fast fibre laser systems based on SESAM technology: new horizons and applications,” New J. Phys. 6, 177 (2004). 6. J.-H. Lin, W.-H. Yang, W.-F. Hsieh, and K. -H. Lin, “Low threshold and high power output of a diode-pumped nonlinear mirror mode-locked Nd:GdVO4 laser,” Opt. Express 13, 6323-6329 (2005). 7. J. W. Lou and M. Currie, “High-energy saturable absorber mode-locked fiber laser system,” Opt. Lett. 30, 406-408 (2005). 8. C. K. Nielsen and S. R. Keiding, “All-fiber mode-locked fiber laser,” Opt. Lett. 32, 1474-1476 (2007). 9. J. Chen, J. W. Sickler, E. P. Ippen, and F. X. Kärtner, “High repetition rate, low jitter, low intensity noise, fundamentally mode-locked 167 fs soliton Er-fiber laser,” Opt. Lett. 32, 1566-1568 (2007). #106038 - $15.00 USD Received 6 Jan 2009; revised 18 Feb 2009; accepted 21 Feb 2009; published 11 Mar 2009 (C) 2009 OSA 16 March 2009 / Vol. 17, No. 6 / OPTICS EXPRESS 4806