臺灣博碩士論文加值系統

在寬頻的波長多工光纖通信系統中，由於波道佔用的波長範圍寬，與總光功率高，光纖的非線性效應將會造成光信號品質劣化與變形。本論文主要考慮由於非線性的拉曼效應對於寬頻的波長多工系統將之影響，與補償波道間拉曼串音的方法。我們使用增益頻譜傾斜的光放大器，增加短波長波道的功率，與減少長波長波道的功率，以補償拉曼串音造成的功率轉換。我們考慮26個波道，每個波道訊號率10Gb/s，傳輸距離6,000公里，信號格式為瞬時頻率調變歸零信號。系統使用光放大器做光纖損失補償，補償週期為50公里。補償光纖色散方面，考慮對稱式色散地圖，其色散補償週期為500公里，以色散補償光纖作為色散補償元件。我們分別考慮動態增益補償與固定增益補償兩種補償方式。當不使用放大器對拉曼串音作補償時，在短波長波道的品質因數Q值由於受拉曼串音的影響，明顯低於平均Q值，而在長波長波道的Q值明顯高於平均Q值。使用增益頻譜傾斜光放大器補償拉曼串音，各波道之Q值在短波長區域被提高，在長波長區域被降低。各波道的Q值分佈都接近平均Q值，也就是受拉曼串音影響的波道之Q值有明顯改善。數值結果顯示在放大器固定增益補償的效果要比動態增益補償稍好。在拉曼補償週期為500公里時，系統各波道可以得到最佳的品質因數，並且系統品質因數反而比沒有拉曼散射的情況要好。與無拉曼散射的情況相比，短波長波道的Q值經適當增益補償後，只有些微下降，但在長波長波道則有明顯增加，所以Q值的改善主要來自長波長波道。其原因是由於拉曼增益與光功率相關，使得長波長信號功率被短波長放大的比例比雜訊功率來的高，而提高在長波長波道的信號雜訊比。

中文摘要..................................................i
英文摘要................................................iii
致謝.....................................................iv
目錄......................................................v
圖目錄...................................................vi
第一章 序論...............................................1
第二章 理論背景...........................................3
2-1 光纖傳輸波動方程式.................................3
? 2-2 光纖的線性效應.....................................4
? 2-3 光纖的非線性效應...................................6
? 2-4 CRZ信號產生方法....................................9
第三章 傳輸系統架構......................................10
?3-1 系統傳輸參數.......................................10
?3-2 信號傳輸品質評估...................................11
第四章 光放大器補償拉曼串音..............................13
4-1 連續波模式的拉曼串音..............................13
4-2 動態增益補償與固定增益補償........................14
第五章 數值模擬與分析....................................15
5-1 考慮預先瞬時頻率(chirping)的信號傳輸..............16
5-2 改變各波道放大器增益值補償拉曼散射之傳輸品質......17
第六章 討論..............................................20
參考文獻.................................................22

[1] P. C. Becker, N. A. Olsson, and J. R. Simpson, Erbium-doped fiber amplifiers: Fundamentals and Technology, ( Academic, Boston, Mass.), 1999.
[2] G. P. Agrawal, Nonlinear Fiber Optics, 2nd ed. ( Academic, Boston, Mass.), 1995.
[3] A. R. Chraplyvy, ” Limitations on lightwave communications imposed by optical-fiber nonlinearities,”IEEE.J. Lightwave Technol, vol.8. p. 1548, 1990.
[4] A. Chraplyvy, ” Systems impact of fiber nonlinearities, ” Short Course Notes of OFC’ 94, Feb. 21, 1994.
[5] V. J. Mazurczyk, G. Shaulov, and E. A. Golovchenko,” Accumulation of gain tilt in WDM amplified systems due to Raman crosstalk,” IEEE Photon. Technol. Lett., vol. 12, p1531, 2000.
[6] W. Ding, Z. Chen, D. Wu, and A. Xu,” Asymmetry of Raman crosstalk in wavelength division multiplexing transmission systems,” Electron. Lett., vol. 38, p. 1265, 2002.
[7] R. A. Fisher, B. R. Suydam, and D. Yevick, ” Optical phase conjugation for time-domain undoing of dispersive self-phase-modulation effects, ” Opt. Lett., vol. 8, p. 611, 1983.
[8] S. Chi and S. Wen, ” Recovery of soliton self-frequency shift by optical phase conjugation, ” Opt. Lett., vol. 19, p. 1705, 1994.
[9] S. Watanabe and T. Chikama, “Cancellation of four-wave mixing in multichannel fiber transmission by midway optical phase conjugation,” Electron. Lett., vol. 30, p. 1156, 1994.
[10] A. Royset, S. Y. Set, I. A. Goncharenko, and R.I Laming, ” Linear and nonlinear dispersion compensation of short pulse using midspan Spectral inversion,”IEEE Photon. Tech. Lett., vol. 8. p. 449, 1996
[11] P. Nouchi, P. Sansonetti, S. Landais, S. Borne, G. Borre’, C. Brechm Y Boniort, B. Perrin, J. J. Girard, and J. Auge’, ” Low loss dispersion-shifted single-mode fiber with high nonlinear effective area, ”OFC’95., San Diego, CA, 1995, Paper ThH2.
[12] S. Wen,” Bi-end dispersion compensation for ultra-long optical communication systems,” IEEE J. Lightwave Technol., vol. 17, p. 792, 1999.
[13] Senfar Wen and Tsung-Kun Lin," Ultralong Lightwave systems with incomplete dispersion compensations," IEEE J. Lightwave Technol., revised.
[14] N. Henmi T. Saito M. Yamaguchi and S. Fujita” 10-Gb /s 100-km normal fiber transmission experiment employing a modifield prechirp technique” OFC’91 San Diego CA, 1991 Paper TuO2  p. 54.
[15] N. Henmi T. Saito and T. Ishida” Prechirp technique as a linear dispersion compensation for ultrahigh-speed long-span intensity modulation direct detection optical communication system” IEEE J. Lightwave Technol. vol. 12 p. 1706 1994.
[16] S. T. Cundiff, B. C. Collings, L. Boivin, M. C. Nuss, K. Bergman, W. H. Knox, and S. G. Evangelides, Jr., “Propagation of highly chirped pulses in fiber-optic communications systems,” J. Lightwave Technol., vol. 17, p. 811, 1999.
[17] A. Hodzic, B. Konrad, and K. Petermann,” Prechirp in NRZ-based 40-Gb/s single-channel and WDM transmission systems,” IEEE Photon. Technol. Lett., vol. 14, p. 152, 2002.
[18] A. N. Pilipetskii, V. J. Mazurczyk, and C. J. Chen,” The effect of dispersion compensation on system performance when nonlinearities are important,” IEEE Photon. Technol. Lett., vol. 11, p 284, 1999.
[19] C. J. Anderson and J. A. Lyle," Technique for evaluating system performance using Q factor in numerical simulations exhibiting intersymbol interference," Electron. Lett., vol. 30, p. 71, 1994.
[20] H. S. Seo,K. Oh,W.Shin,U. C. Peak,”Compensation of Raman-Induced Crosstalk Using a Lumped Germanosilicate Fiber Raman Amplifier in the 1.571-1.591-μm Region” IEEE Photon. Technol. Lett., vol. 13, p28, 2001.