【正文】 Gonz225。參考文獻(xiàn)1. A. E. H. Oehler, S. C. Zeller, K. J. Weingarten, and U. Keller,“ Broad multiwavelength source with 50 GHz channel spacing for wavelength division multiplexing applications in the tele C band,” Opt. Lett. 33, 2158–2160 (2008).2. . Liu, X. Dong, P. Shum, S. Yuan, G. Kai, and X. Dong, “Stable roomtemperature multiwavelength lasing realization in ordinary erbiumdoped fiber loop lasers,” Opt. Express 14, 9293–9298 (2006).3. , D. Dagel, and S. T. Sanders, “Simple multiwavelength timedivision multiplexed light source for sensing applications,” Opt. Lett. 33, 738–740 (2008).4. Z. Chen, S. Ma, and N. K. Dutta, “Multiwavelength fiber ring laser based on a semiconductor and fiber gain medium,” Opt. Express 17, 1234–1239 (2009).5. ,F. Fresi, “Continuously spacingtunable multiwavelength semiconductoropticalamplifierbased fiber ring laser incorporating a superimposed chirped fiber Bragg grating,” Opt. Lett. 32, 1032–1034 (2007).6. C. S. Jun and B. Y. 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Shee, M. H. AlMansoori, A. Ismail, S. Hitam, and M. A. Mahdi, “Double Brillouin frequency shift through circulation of oddorder Stokes signal,” Appl. Opt. 49, 3956–3959 (2010).12. Y. G. Shee, M. H. AlMansoori, A. Ismail, S. Hitam, and M. A. Mahdi1, “Multiwavelength Brillouinerbium fiber laser with doubleBrillouinfrequency spacing,” Opt. Express 19, 1699–1706 (2011).13. M. A. Mirza and G. Stewart, “Theory and design of a simple tunable Sagnac loop filter for multiwavelength fiber lasers,” Appl. Opt. 47, 5242–5252 (2008).14. J. Wang, K. Zheng, J. Peng, L. Liu, J. Li, and S. Jian, “Theory and experiment of a fiber loop mirror filter of twostage polarizationmaintaining fibers and polarization controllers for multiwavelength fiber ring laser,” Opt. Express 17,10573–10583 (2009).15. M. A. Ummy, N. Madamopoulos, A. Joyo, M. Kouar, and R. Dorsinville, “Tunable multiwavelength SOA based linear cavity dualoutput port fiber laser using Lyot–Sagnac loop mirror,” Opt. Express 19, 3202–3211 (2011).16. A. Gonz225。峰值線寬越小，光纖激光器的抗環(huán)境干擾能力越弱。波長間隔可以通過改變基于Eq（5）的短PMF長度進(jìn)行調(diào)諧。偏振偏轉(zhuǎn)角度可以通過調(diào)整PC1和PC2進(jìn)行調(diào)諧，因此輸出激光的波長和波長間隔也可以調(diào)諧。PMF的長度為5m和2m。因此，雙環(huán)的透射率可以描述為： （5）很明顯，雙Sagnac環(huán)的透射率與長度或者基于Eq（5）兩段PMF的折射率差有關(guān)。設(shè)為通過PC和PMF的光學(xué)矢量，為通過PC和PMF的光學(xué)矢量。由于PMF的高雙折射影響，光束在兩個(gè)軸（快軸和慢軸）上出現(xiàn)相位差。2．實(shí)驗(yàn)裝置和操作原則提出的多波長光纖激光器的實(shí)驗(yàn)裝置示意圖如圖1（a）中所示。采用這種結(jié)構(gòu)，可以實(shí)現(xiàn)保持線寬不變的波長間隔可調(diào)諧，以及保持波長間隔不變的線寬調(diào)諧。美國光學(xué)學(xué)會 2012OCIS 編碼：, , , 1．引言工作在波長1550nm附近的多波長光纖激光器已經(jīng)吸引了許多人的興趣，它可以應(yīng)用于密集波分復(fù)用（DWDM）系統(tǒng)，精細(xì)光譜學(xué)，光纖傳感和微波（RF）光電[14]等領(lǐng)域。使用瓊斯矩陣分析了單個(gè)和兩個(gè)Sagnac環(huán)梳狀濾波器的特性。例如，作為一種可調(diào)諧EDF激光器，帶有單個(gè)高雙折射光纖Sagnac環(huán)的多波長光纖激光器已經(jīng)提出[1315]。本文模擬分析了單個(gè)和兩個(gè)Sagnac環(huán)的梳狀濾波器的特征。多波長光纖激光器通過雙Sagnac環(huán)進(jìn)行調(diào)諧。Sagnac環(huán)的輸出特性可以用Jones矩陣分析。透射率為： （4）這個(gè)說明單Sagnac環(huán)的透射率與偏振偏轉(zhuǎn)角度和兩個(gè)軸的相位差有關(guān)。圖中我們能看到濾波周期在變而濾波帶寬不變。由于增益譜平坦度和偏振衰減的限制，濾波帶寬的部分光將被抑制。在實(shí)驗(yàn)中，我們觀察到輸出波長間隔可以通過調(diào)整兩個(gè)PC進(jìn)行調(diào)諧。根據(jù)模擬和實(shí)驗(yàn)的結(jié)果，波長間隔隨著短PMF長度增大而變小但帶寬保持不變。模擬結(jié)果表明雙Sagnac環(huán)比單Sagnac環(huán)具有更好的可調(diào)諧性和可控性。o, B. IbarraEscamilla, and E. A. Kuzin, “Switchable and tuneable multisavelength Erdoped fibre ring laser using Sagnac filters,” Laser Phys. 20, 720–725 (2010).外文原文一：Tunable multiwavelength fiber laser basedon a double Sagnac HiBi fiber loopTianshu Wang,* Xuefeng Miao, Xuefang Zhou, and Sheng QianCollege of Communication Engineering, Hangzhou Dianzi University, Hangzhou 310018, China*Corresponding author: tianshuwReceived 12 December 2011。o, B. Ibarra Escamilla, and E. A. Kuzin, “Switchable and tuneable multisavelength Erdoped fibre ring laser using Sagnac filters,” Laser Phys. 20, 720–725 (2010).譯文二：可調(diào)諧全光纖雙折射梳狀濾波器Raymond ，ChangSeok Kim,Jin ,巴爾的摩，約翰霍普金斯大學(xué)電氣與計(jì)算機(jī)工程部門，MD 21218，Email：jkang引言可調(diào)諧光梳狀濾波器已經(jīng)被證明可用于發(fā)展波分復(fù)用光學(xué)光纖通信系統(tǒng)中的多波長激光器。如方程式2所示，波長間隔取決于傳輸峰的相鄰距離。這里我們的工作是把一個(gè)兩段Lyot濾波器擴(kuò)展成一個(gè)三段Lyot濾波器和三、四段SagnacLyot濾波器。通常n元SagnacLyot梳狀濾波器有效長度的數(shù)量為。圖1b，2b和3b顯示了三種濾波器測量的傳輸光譜。濾波器響應(yīng)間隔非常平坦（）和一致。參考文獻(xiàn)1. N. Park, . Dawson, and ,“MultipleWavelength Operation of an ErbiumDoped Fiber Laser,” IEEE Photon. Tech. Lett.,1992, 4, 540–541。其中Lyot濾波器只需要少量光纖片段就能提供大量波長間隔數(shù)量。插入損耗主要是由于偏振控制器中光纖環(huán)半徑小，產(chǎn)生了明顯的彎曲損耗，并且保偏和非保偏光纖的接合也會產(chǎn)生損耗。實(shí)驗(yàn)中搭建了兩個(gè)獨(dú)立的濾波器：1）一個(gè)由=，=，=。在PM光纖片段的兩邊都使用光纖半波片，從而有效控制偏振態(tài)。旋轉(zhuǎn)每段光纖可以改變有效長度，比如快軸相對于慢軸為 +45176。這種濾波器可以很容易應(yīng)用于多波長光纖激光器結(jié)構(gòu)中。 published 28 March 2012A tunable multiwavelength fiber laser based on double Sagnac loops is proposed and demonstrated. Comb filter characteristics of single and double Sagnac loops are analyzed by Jones matrix. Simulated results show that thereare better tunability and controllability with double loops than with a singleloop, and this also has been confirmed by experimental results. By adjusting the polarization controller and the length of the polarization maintaining fiber the wavelength range, wavelength spacing, and laser linewidth can be tuned. Experimental results indicate that the linewidth of the multiwavelength fiber la