本論文中，我們以頻譜塑形技術設計一台中心波長為1064奈米的摻鐿光纖啁啾脈衝放大器。種子光源為一台全正色散被動鎖模光纖雷射，初階放大器與主要放大器分別採用10微米與30微米纖核直徑的非極化保持摻鐿光纖。雷射脈衝重複率約為15 MHz，頻譜寬度約為9 奈米，輸出功率可達28 瓦。實驗結果顯示，此脈衝經過光纖放大器後無法壓縮回次皮秒脈衝。經由非線性薛丁格方程式數值模擬結果得知，頻譜寬度及頻譜形貌皆會影響脈衝壓縮品質，其中頻譜形貌影響甚劇。因此，我們在種子雷射腔外使用帶通濾波器進行頻譜塑形，使種子光源頻譜形狀更貼近高斯形貌。經由這種簡易的頻譜塑形後可獲得更短而品質更好的脈衝，其最高輸出脈衝能量可達約2微焦耳。在最佳非線性效應條件下，經由脈衝壓縮後，本雷射系統輸出脈衝之最高尖峰功率可達60千瓦，半高全寬約350飛秒，主要脈衝包含40%的脈衝能量。

In this thesis, we studied experimentally and theoretically spectrally shaped chirped pulse amplification (CPA) of a high-power ytterbium-doped fiber laser amplifier with a central wavelength at 1064 nm. The seed source is an all-normal dispersion (ANDi) passively mode-locked fiber laser. For the amplified stages, we employ the 10 m-core and 30 m-core non-polarization maintaining Yb-doped fiber to be used in the pre-amplifier and main amplified stages respectively. The seed laser generated pulses with a repetition rate of ~15 MHz, spectral bandwidth ~ 9 nm and an output power of 28 W. According to the numerical simulation results of the nonlinear Schrodinger equation (NLSE), both spectral bandwidth and spectral profile of the seed laser would affect the outcome of pulse compression. Especially, the spectral profile of the seed pulse plays a dominant role. Thus, a spectral filter was employed such that the spectrum of the seed laser output was Gaussian-like. The maximum output of the pulse energy can be as high as 2.0 J. The peak power of the best compressed pulse was ~ 60 kW and the pulse duration was as short as 350 fs (FWHM). Approximately 40% of the pulse energy is in the main pulse.

1. A. Ancona, S. Döring, C. Jauregui, F. Röser, J. Limpert, S. Nolte, and A. Tünnermann, "Femtosecond and picosecond laser drilling of metals at high repetition rates and average powers," Optics letters 34(21), 3304-3306 (2009)
2. B.N. Chichkov, C. Momma, S. Nolte, F. von Alvensleben, and A. Tünnermann, "Femtosecond, picosecond and nanosecond laser ablation of solids," Applied Physics A 63(2), 109-115 (1996)
3. G.P. Agrawal, Nonlinear fiber optics. Academic press. (2007)
4. R.L. Farrow, D.A. Kliner, G.R. Hadley, and A.V. Smith, "Peak-power limits on fiber amplifiers imposed by self-focusing," Optics letters 31(23), 3423-3425 (2006)
5. D.N. Schimpf, T. Eidam, E. Seise, S. Hädrich, J. Limpert, and A. Tünnermann, "Circular versus linear polarization in laser-amplifiers with Kerr-nonlinearity," Optics Express 17(21), 18774-18781 (2009)
6. M. Pessot, P. Maine, and G. Mourou, "1000 times expansion/compression of optical pulses for chirped pulse amplification," Optics Communications 62(6), 419-421 (1987)
7. P. Maine, D. Strickland, P. Bado, M. Pessot, and G. Mourou, "Generation of ultrahigh peak power pulses by chirped pulse amplification," Quantum Electronics, IEEE Journal of 24(2), 398-403 (1988)
8. C.J. Koester and E. Snitzer, "Amplification in a Fiber Laser," Applied Optics 3(10), 1182-1186 (1964)
9. Y. Jeong, J.K. Sahu, D.N. Payne, and J. Nilsson. Ytterbium-doped large-core fiber laser with 1 kW continuous-wave output power. in Advanced Solid-State Photonics. of Conference. Santa Fe, New Mexico: Optical Society of America. (2004)
10. J. Yoonchan, J. Nilsson, J.K. Sahu, D.N. Payne, R. Horley, L.M.B. Hickey, and P.W. Turner, "Power Scaling of Single-Frequency Ytterbium-Doped Fiber Master-Oscillator Power-Amplifier Sources up to 500 W," Selected Topics in Quantum Electronics, IEEE Journal of 13(3), 546-551 (2007)
11. W. Liu, D.N. Schimpf, T. Eidam, J. Limpert, A. Tünnermann, F.X. Kärtner, and G. Chang, "Pre-chirp managed nonlinear amplification in fibers delivering 100 W, 60 fs pulses," Optics Letters 40(2), 151-154 (2015)
12. R. Paschotta. Fiber Amplifiers: More ASE for Larger Core with Higher NA? 2007 [cited Access; Available from: http://www.rp-photonics.com/spotlight_2007_08_06.html. (2007)
13. N.P. Barnes and B.M. Walsh, "Amplified spontaneous emission-application to Nd:YAG lasers," Quantum Electronics, IEEE Journal of 35(1), 101-109 (1999)
14. J. Limpert, F. Stutzki, F. Jansen, H.-J. Otto, T. Eidam, C. Jauregui, and A. Tunnermann, "Yb-doped large-pitch fibres: effective single-mode operation based on higher-order mode delocalisation," Light Sci Appl 1, e8 (2012)
15. H.-W. Chen, T. Sosnowski, C.-H. Liu, L.-J. Chen, J.R. Birge, A. Galvanauskas, F.X. Kärtner, and G. Chang, "Chirally-coupled-core Yb-fiber laser delivering 80-fs pulses with diffraction-limited beam quality warranted by a high-dispersion mirror based compressor," Optics Express 18(24), 24699-24705 (2010)
16. T.T. Alkeskjold, M. Laurila, L. Scolari, and J. Broeng, "Single-mode ytterbium-doped large-mode-area photonic bandgap rod fiber amplifier," Optics Express 19(8), 7398-7409 (2011)
17. P. Russell, "Photonic Crystal Fibers," Science 299(5605), 358-362 (2003)
18. R.H. Stolen, J. Botineau, and A. Ashkin, "Intensity discrimination of optical pulses with birefringent fibers," Optics Letters 7(10), 512-514 (1982)
19. X.D. Cao and D.D. Meyerhofer, "Nonlinear birefringence of optical fibers," Optics Communications 109(1–2), 151-154 (1994)
20. K. Lu and N.K. Dutta, "Spectroscopic properties of Yb-doped silica glass," Journal of Applied Physics 91(2), 576-581 (2002)
21. R. Paschotta, J. Nilsson, A.C. Tropper, and D.C. Hanna, "Ytterbium-doped fibre amplifiers," IEEE Journal of quantum electronics 33(7), 1049-1056 (1997)
22. C.V. Raman and K.S. Krishnan, "A new type of secondary radiation," Nature 121(3048), 501-502 (1928)
23. R.H. Stolen, E.P. Ippen, and A.R. Tynes, "Raman Oscillation in Glass Optical Waveguide," Applied Physics Letters 20(2), 62-64 (1972)
24. M.D. Perry, T. Ditmire, and B. Stuart, "Self-phase modulation in chirped-pulse amplification," Optics letters 19(24), 2149-2151 (1994)
25. S. Teich, "Fundamental of Photonics, 2nd edition ed.," (1991)
26. S.-D. Yang, "Ultrafast Optics Lecture notes," (2009)
27. F.Ö. Ilday, J.R. Buckley, W.G. Clark, and F.W. Wise, "Self-Similar Evolution of Parabolic Pulses in a Laser," Physical Review Letters 92(21), 213902 (2004)
28. A. Chong, J. Buckley, W. Renninger, and F. Wise, "All-normal-dispersion femtosecond fiber laser," Optics Express 14(21), 10095-10100 (2006)
29. N. Kuse, Y. Nomura, A. Ozawa, M. Kuwata-Gonokami, S. Watanabe, and Y. Kobayashi, "Self-compensation of third-order dispersion for ultrashort pulse generation demonstrated in an Yb fiber oscillator," Optics Letters 35(23), 3868-3870 (2010)
30. S. Zhou, L. Kuznetsova, A. Chong, and F. Wise, "Compensation of nonlinear phase shifts with third-order dispersion in short-pulse fiber amplifiers," Optics Express 13(13), 4869-4877 (2005)
31. A. Ghatak and K. Thyagarajan, An introduction to fiber optics. Cambridge university press. (1998)
32. Malitson, "Refractive Index of Fused silica (fused quartz)," (1965)
33. "Corning product catalog of SMF-28 optical fiber," (2002)
34. E. Treacy, "Optical pulse compression with diffraction gratings," Quantum Electronics, IEEE Journal of 5(9), 454-458 (1969)
35. Newport product catalog of Plane Ruled Reflection Grating, 12.5mm, 1000nm, 36.8°, 1200 Gr/mm. 2015 [cited Access; Available from: http://search.newport.com/?q=*&x2=sku&q2=05RG1200-1000-2. (2015)
36. RP photonics of Nonlinear Index 2015 [cited Access; Available from: http://www.rp-photonics.com/nonlinear_index.html?s=ak. (2015)
37. S.H. Saeid. Computer simulation and performance evaluation of single mode fiber optics. in Proceedings of the World Congress on Engineering. of Conference. (2012)
38. Thorlabs product catalog of 1000 - 1250 nm Bandpass Filters. 2015 [cited Access; Available from: https://www.thorlabs.de/newgrouppage9.cfm?objectgroup_id=1000&pn=FL051064-3. (2015)
39. Wikipedia, "Full width at half maximum," (2014)
40. G. Chamberlain, Optical fiber characterization. US Government Printing Office. (1983)
41. K.-T. Chan and W.-H. Cao, "Enhanced compression of fundamental solitons in dispersion decreasing fibers due to the combined effects of negative third-order dispersion and Raman self-scattering," Optics Communications 184(5–6), 463-474 (2000)
42. A. Braun, S. Kane, and T. Norris, "Compensation of self-phase modulation in chirped-pulse amplification laser systems," Optics Letters 22(9), 615-617 (1997)
43. S. Wang, B. Liu, C. Gu, Y. Song, C. Qian, M. Hu, L. Chai, and C. Wang, "Self-similar evolution in a short fiber amplifier through nonlinear pulse preshaping," Optics Letters 38(3), 296-298 (2013)
44. Y. Deng, C.-Y. Chien, B.G. Fidric, and J.D. Kafka, "Generation of sub-50 fs pulses from a high-power Yb-doped fiber amplifier," Optics Letters 34(22), 3469-3471 (2009)
45. G. Chang, A. Galvanauskas, H.G. Winful, and T.B. Norris, "Dependence of parabolic pulse amplification on stimulated Raman scattering and gain bandwidth," Optics Letters 29(22), 2647-2649 (2004)
46. W. Liu, D.N. Schimpf, T. Eidam, J. Limpert, A. Tünnermann, F.X. Kärtner, and G. Chang, "Pre-chirp managed nonlinear amplification in fibers delivering 100 W, 60 fs pulses," (2014)
47. Y. Liu, W. Li, J. Zhao, D. Bai, D. Luo, and H. Zeng, "High-power pre-chirp managed amplification of femtosecond pulses at high repetition rates," Laser Physics Letters 12(7), 075101 (2015)
48. J. Zhao, W. Li, C. Wang, Y. Liu, and H. Zeng, "Pre-chirping management of a self-similar Yb-fiber amplifier towards 80 W average power with sub-40 fs pulse generation," Optics Express 22(26), 32214-32219 (2014)
49. Lightsmyth Product Catalog of Gratings for Pulse Compression and High Power Beam Combining. 2015 [cited Access; Available from: http://www.lightsmyth.com/product/gratings-for-pulse-compression-and-high-power-beam-combining/. (2015)