本論文為少數模態摻鉻釔鋁石榴石晶體雙纖衣光纖研製與量測之研究，利用雷射加熱基座生長法(Laser heated pedestal growth, LHPG)將Cr4+:YAG晶棒加工製成Cr4+:YAG雙纖衣晶體光纖，藉由電子探測光顯微分析(Electron Probe X-ray Micro-Analysis, EPMA)、能量分散光譜儀(Energy Dispersive Spectroscopy, EDS)、穿透式電子顯微鏡（Transmission electron microscopy, TEM）分析僅數微米纖心之晶體光纖材料結構組成及特性，分析結果顯示LHPG法所生長的晶纖，纖心組成仍為單晶，在生長過程中並未受到外層纖衣材料擴散而破壞。同時測量相關光學量測，包含晶纖折射率、螢光特性以及傳輸特性量測等等。在增益特性的實驗量測，利用單向激發的架構，信號光波長1.4 μm、激發光波長1.06 μm與激發光總功率200 mW，得到1.43 dB之增益，插入損耗為4 dB。而利用雙向激發的架構，得到2.3 dB之增益，皆未得到淨增益(net gain)。與過去纖心直徑為多模態14 μm之Cr4+:YAG雙纖衣晶體光纖所需數瓦的激發功率相比，降低10倍的激發功率閾值(pumping threshold)，表示少數模態的晶纖可減少熱能產生並提高能量使用效率。未來在提升晶體光纖的光學特性上，勢必朝向少數模態甚至單模態(single mode)，不只降低傳輸損耗，更大幅提升元件效率。

Rapid development of fiber-optic communications network requirements increasing in recent years, The WDM technology and invention of anhydrous optical fiber open the possibility for optical fiber transmission bands broaden form 1.3 μm to 1.6 μm. Chromium doped yttrium aluminum garnet crystal fiber has characteristic of 300 nm broadband. Therefore, it’s strongly desirable to develop a broadband fiber amplifier, laser or other active components for extending the flexibility of system architecture design in optical fiber communication.

A few-mode chromium doped yttrium aluminum garnet double-clad crystalline fibers has been demonstrated by employing a modified version of LHPG technique, means using silica-YAG crystal co-drawing and multiple core-tuning process by precisely controlled inter-diffusion between YAG core and silica tube. In this thesis, electron probe x-ray micro-analysis, energy dispersive spectroscopy and transmission electron microscopy were utilized to confirm this fiber structure and composition. This fiber has gross gain about 2.3 dB with dual pumped by few hundred mini Watt. Significantly reduce the pump power threshold. Compared with the last large core size, few-mode (small core size) chromium doped yttrium aluminum garnet double-clad crystalline fibers has lower heat effect and higher power efficiency. To enhance the optical properties towards few modes or even single mode, not only reduce the transmission loss, but improve the device efficiency.


Key words: Laser heated pedestal growth, Cr4+:YAG, Double-clad Crystal Fiber, gain

中文摘要 i
英文摘要 ii
目錄 iii
圖目錄 v
表目錄 viii
第一章 緒論 1
1.1 研究背景 1
1.2 研究動機與目的 2
1.3 論文架構 3
第二章 Cr4+:YAG晶體特性分析 4
2.1釔鋁石榴石的特性 4
2.2Cr4+:YAG電荷補償[10]~[15] 8
2.3Cr4+:YAG能階模型及吸收射頻譜 11
2.4 Cr4+:YAG雙纖衣晶體光纖中之傳輸[18] 14
第三章 少數模態Cr4+:YAG雙纖衣晶體光纖製程 18
3.1晶體光纖之生長 18
3.2晶體光纖端面之研磨拋光 24
3.3 Cr4+:YAG雙纖衣晶體光纖散熱封裝 29
3-4 晶體光纖直徑變化分析 30
第四章 雙纖衣Cr4+:YAG晶體光纖之晶體分析 33
4.1電子探測光顯微分析 33
4.2掃描式電子顯微鏡 36
4.3穿透式電子顯微鏡分析 41
第五章 Cr4+:YAG雙纖衣晶體光纖特性量測 49
5.1折射率量測 49
5.2螢光量測 51
5.3遠場量測 53
5.4增益特性量測 54
第六章 結論 60
第七章 參考文獻 61

[1] H. Osanai, T. Shioda, T. Moriyama, and S. Araki, "Effects of Dopants on Transmission Loss of Low OH Content Optical Fibers," Electron. Lett. 12, 549, 1976.
[2] C. C. Lai, H. J. Tsai, K. Y. Huang, K. Y. Hsu, Z. W. Lin, K. D. Ji, W. J. Zhuo, and S. L. Huang, “Cr4+:YAG double-clad crystal fiber laser,” Optics Letters, 33, 2919-2921, Dec. 2008.
[3] 黃光瑤，「摻鉻釔鋁石榴石晶體光纖之超頻寬自發輻射放大光源之研究」，碩士論文，國立中山大學, 2003。
[4] M. J. F. DIGONNET, C. J. GAETA, D. O’MEARA, AND H. J. SHAW, “Clad Nd:YAG fibers for laser applications,” Journal of Lightwave Technology, Vol. Lt-5, No. 5, May. 1987.
[5] R. S. Feigelson, W. L. Kway, and R. K. Route, “Single crystal fibers by the laser-heated pedestal growth method,” Opt. Eng., vol. 24, pp. 1102-1107, 1985.
[6] 余樹楨，”晶體之結構與性質”，渤海堂，2000 年。
[7] Eschenfleder. A. H. “Magnetic Bubble Technology.” Solid-State Sciences 14.
Springer-Verlag. New York. 1981
[8] Gemological Institute of America, GIA Gem Reference Guide 1995, ISBN 0-87311-019-6
[9] B. M. Tissue, W. Jia, L. Lu, and W. M. Yen, “Coloration of chromium-doped yttrium aluminum garnet single-crystal fibers using a divalent codopant,” J. A. P., vol. 70, pp. 3775-3777, 1991.
[10] S. Ishibashi and K. Naganuma, “Diode pumped Cr4+:YAG single crystal fiber laser,” in Advanced Solid-State Lases, OSA Technical Digest, Davos, Switzerland, p. 103, 2000.
[11] S. A. Markgraf, M. F. Pangborn, and R. Dieckmann, “Influence of different divalent co-dopants on the Cr4+ of Cr-doped Y3Al5O12 content,” Journal of Crystal Growth 180, 81, 1997.
[12] S. Kuck, K. Petermann, and G. Huber, “Spectroscopic investigation of the Cr4+-center in YAG,” OSA Proceedings on Advanced Solid-State Lasers, vol. 10, pp. 92-94, 1991.
[13] B. M. Tissue, W. Jia, L. Lu, and W. M. Yen, “Coloration of chromium-doped yttrium aluminum garnet single-crystal fibers using a divalent codopant,” J. Appl. Phys., vol. 70, pp. 3775-3777, 1991.
[14] S. Ishibashi, K. Naganuma, and I. Yokohama, “Cr,Ca:Y3Al5O12 laser crystal
grown by the laser-heated pedestal growth method,” J. Crys. Growth, vol. 183, pp. 614-621, 1998.
[15] K. Y. Huang, K. Y. Hsu, and S. L. Huang, “Analysis of ultra-broadband amplified spontaneous emissions generated by Cr4+:YAG single and glass-clad crystal fibers,” IEEE/OSA Journal of Lightwave Technology, 26, pp. 1632-1639, 2008.
[16] A. Sennaroglu, “Analysis and optimization of lifetime thermal loading in continuous-wave Cr4+-doped solid-state lasers,” J. Opt. Soc. Am., vol. 18, pp. 1578-1586, 2001.
[17] H. Eilers, W. Dennis, W. M. Yen, S. Kuck, K. Peterman, G. Huber, and W. Jia, “Performance of a Cr:YAG laser,” IEEE J. Quantum Electron. 29, 2508–2512, 1993.
[18] “Optical fiber communications,” by Gerd Keiser, fourth edition.
[19] C. A. Burrus and J. Stone, “Single-crystal fiber optical devices: A Nd:YAG fiber laser,” Appl. Phys. Lett., vol. 26, pp. 318-320, 1975.
[20] S. Ishibashi, K. Naganuma, and I. Yokohama, “Cr,Ca:Y3Al5O12 laser crystal grown by the laser-heated pedestal growth method,” J. Crys. Growth, vol. 183, pp. 614-621, 1998.
[21] Wittry, David B. (1958). "Electron Probe Microanalyzer", US Patent No 2916621, Washington, DC: U.S. Patent and Trademark Office.
[22] Jansen, W.; Slaughter, M. (1982). "Elemental mapping of minerals by electron microprobe". American Mineralogist 67 (5–6): 521–533.
[23] “Scanning Electron Microscopy and X-ray Microanalysis”, Third Edition, by Joseph Goldstein, Dale Newbury, David Joy, Charles Lyman, Patrick Echlin, Eric Lifshin, Linda Sawyer, and Joseph Michael, Kluwer Academic/Plenum Publishers, 2003 ISBN 0306472929
[24] Transmission electron microscopy [electronic resource] : a textbook for materials science, by David B. Williams, C. Barry Carter , Boston, MA : Springer US, 2009.
[25] M. A. Gulgun, W. Y. Ching, Y. N. Xu, and M. Ruhle, “Electron states of YAG probed by energy-loss near-edge spectrometry and ab initio calculations,” Phil. Mag. B, vol. 79, pp. 921-940, 1999.
[26] D. Gloge, “Weakly guiding fibers,” Appl. Opt., vol. 10, pp. 2252-2258, Oct. 1971.
[27] 黃光瑤，博士論文，” 摻鉻釔鋁石榴石晶體光纖之生長系統改良，2009年。