本研究之目的在開發出具有高功率、短波長、體積小等優點，可應用在微機械加工、雷射雷達、水下探測、生化科技等方面的固態藍光雷射。藉由成本低、體積小且使用簡單的被動式Q開關技術，以有效提高雷射的峰值功率，並整合能以非線性頻率轉換產生藍光雷射且符合經濟效益的腔內倍頻技術，我們研發出峰值功率高達83 W，波長473 nm的小型全固態高功率藍光雷射。

對於Nd:YAG的4F3/2 R 4I9/2準三能階雷射輸出，受限於重複吸收損耗，使得光對光轉換效率較其4F3/2 R 4I11/2的四能階雷射為低，且重複吸收損耗會隨著增益介質溫度變化而改變，故對一個準三能階雷射系統的性能及穩定性影響甚鉅，因此，除了對KNbO3、BBO及LBO等三種非線性晶體在腔內倍頻產生高功率藍光雷射做有系統的研究外，並以數值分析的方式探討重複吸收損耗對準三能階被動Q開關雷射系統的影響。如今，實驗結果已達峰值功率83 W，脈衝寬度僅10.6 ns的脈衝式藍光雷射。就目前得到的文獻資料顯示，這是第一個同時整合被動式Q開關及腔內倍頻技術的小型全固態高功率脈衝式藍光雷射。

The purpose of this study is to develop a solid-state blue laser which has advantages of high power, short wavelength, and compact. It can be applied in micromaching, LIDAR, underwater ranging, biochemical techniques, and so forth. We increased the peak power of the laser effectively by a low-cost, small, and easy-use passive Q-switching technique. In addition, intracavity frequency-doubling is an economic way to achieve non-linear frequency conversion for blue generation. By integrating of these two techniques, we develop a compact all solid-state high-power blue laser with 83 W peak power at 473 nm.

Restricted to reabsorption loss, the optical to optical conversion efficiency of 4F3/2 → 4I9/2 quasi-three-level laser is lower than 4F3/2 → 4I11/2 four-level laser for Nd:YAG crystal. The reabsorption loss will change with the temperature variation of the gain medium, it enormously affects to the performance and stability of quasi-three-level lasers. Therefore, in addition to make systematic studies of the conversion efficiency of KNbO3, BBO, LBO as the intracavity SHG crystals for generation of high-power blue laser, we use the numerical analysis to investigate the influence of reabsorption loss to quasi-three-level passive Q-switching laser. At present, blue laser with peak power of 83 W and pulse width of 10.6 ns was generated as a result. To our knowledge, the compact all solid-state high-power pulsed blue laser is demonstrated for the first time by integrating of passive Q-switching and intracavity frequency-doubling simultaneously.

第一章 緒論 1
第二章 準三能階被動Q開關雷射 4
2.1 Nd:YAG與Nd:YVO4雷射晶體 4
2.2 準三能階與四能階雷射系統 10
2.3 Q開關雷射的工作原理 14
2.4 Q開關雷射的種類 16
第三章 腔內倍頻之被動式Q開關藍光雷射 21
3.1 腔內倍頻之工作原理 21
3.2 影響倍頻效率因素 25
3.3腔內倍頻之被動式Q開關藍光雷射 30
第四章 準三能階被動Q開關雷射之理論模擬 48
4.1 準三能階被動Q開關雷射之理論模型 48
4.2 程式模擬與討論 54
第五章 結論 59
參考文獻 61
中英對照表 63
附錄 66

[1] D. Hargis and A. Earman, "Diode-pumped microlasers promise portable projectors," Laser Focus World, May, 1998.
[2] D. Hargis and A. Earman, "Lasers replace conventional technology in display designs," Laser Focus World, July, 1998.
[3] R. G. Batchko, M. M. Fejer, R. L. Byer, D. Woll, R. Wallenstein, V. Y. Shur,and L. Erman, "Continuous-wave quasi-phase-matched generation of 60 mW at 465 nm by single-pass frequency-doubling of a laser-diode in backswitch-poled lithium-niobate," Optics Letters, Vol. 24, No. 18, pp. 1293-1295, 1999.
[4] Y. Furukawa, K. Kitamura, S. Takekawa, A. Alexandrovski, G. Foulon, R. K. Route, and M. M. Fejer, "Elimination of photorefraction and green-induced -infrared-absorption in MgO-doped near-stoichiometric LiNbO3," Advanced Solid-State Lasers, paper MF8-1, Davos, Switzerland, 2000.
[5] M. Bode, I. Freitag, A. Tunnermann, and H. Welling, "Frequency-tunable 500-mW continuous-wave all-solid-state single-frequency source in the blue spectral region," Optics Letters, Vol. 22, No. 16, pp. 1220-1222, 1997.
[6] M. Pierrou, F. Laurell, H. Karlsson, T. Kellner, C. Czeranowsky, and G. Huber, "Generation of 740 mW of blue-light by intracavity frequency-doubling with a first-order quasi-phase-matched KTiOPO4 crystal," Optics Letters, Vol. 24, No. 4, pp. 205-207, 1999.
[7] C. D. Nabors, "Q-switched operation of quasi-three-level lasers," IEEE Journal of Quantum Electronics, Vol. 30, No. 12, pp. 2896-2901, 1994.
[8] A. Sato, K. Asai, and T. Itabe, "Double-pass-pumped Tm:YAG laser with a simple cavity configuration," Applied Optics, Vol. 37, No. 27, pp. 6395-6400, 1998.
[9] T. Y. Fan, "Optimizing the efficiency and stored energy in quasi-three-level lasers," IEEE Journal of Quantum Electronics, Vol. 28, No. 12, pp. 2692-2697, 1992.
[10] R. J. Beach, "Optimization of quasi-three-level end-pumped Q-switched lasers," IEEE Journal of Quantum Electronics, Vol. 31, No. 9, pp. 1606-1613, 1995.
[11] 崔宗元，"被動式Q開關Nd:YAG/Cr4+:YAG雷射研究，"國立中山大學光電工程研究所碩士論文，1998.
[12] X. Zhang, S. Zhao, O. Wang, Q. Zhang, L. Sun, and S. Zhang, "Optimization of Cr4+-doped saturable-absorber Q-switched lasers," IEEE Journal of Quantum Electronics, Vol. 33, No. 12, pp. 2286-2294, 1997.
[13] S. L. Huang , T. Y. Tsui, C. H. Wang, and F. J. Kao, "Timing jitter reduction of a passively Q-switched laser, " Jpn. J. of Appl. Phys, Vol. 38, L239-241, 1999.
[14] P. L. Huang, H. Z. Cheng, S. L. Huang, "Timing-jitter reduction of passively Q-switched laser by a reentrant 2-mirror ring cavity," CLEO 2000 Technical Digest, pp. 451, 2000.
[15] P. A. Franken, A. E. Hill, C. W. Peter, and G. Weinreich, "Generation of optical harmonics," Phys. Rev. Lett., Vol. 7, pp. 118, 1961.
[16] R. L. Byer, "Diode laser-pumped solid-state lasers," Science, Vol. 239, No. 4841, pp. 742-747, 1988.
[17] W. P. Risk, "Modeling of longitudinally pumped solid-state lasers exhibiting reabsorption losses," J. Opt. Soc. Am. B, Vol. 5, No. 7, pp. 1412-1423, 1988.
[18] T. Y. Fan, and R. L. Byer, "Modeling and CW operation of a quasi-three-level 946 nm Nd:YAG laser," IEEE Journal of Quantum Electronics, Vol. 23, No. 5, pp. 605-612, 1987.
[19] C. F. Gerald, "Applied Numerical Analysis," 2nd ed. Wesley, ch. 8, 1992.
[20] M. E. Innocezi, H. T. Yura, C. L. Fincher, and R. A. Fields, "Thermal modeling of continuous-wave end-pumped solid-state lasers,"Appl. Phys. Lett., Vol. 36, No. 19, pp. 1831-1833, 1990.