Skip navigation

DSpace

機構典藏 DSpace 系統致力於保存各式數位資料(如:文字、圖片、PDF)並使其易於取用。

點此認識 DSpace
DSpace logo
English
中文
  • 瀏覽論文
    • 校院系所
    • 出版年
    • 作者
    • 標題
    • 關鍵字
    • 指導教授
  • 搜尋 TDR
  • 授權 Q&A
    • 我的頁面
    • 接受 E-mail 通知
    • 編輯個人資料
  1. NTU Theses and Dissertations Repository
  2. 電機資訊學院
  3. 光電工程學研究所
請用此 Handle URI 來引用此文件: http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/99086
完整後設資料紀錄
DC 欄位值語言
dc.contributor.advisor黃升龍zh_TW
dc.contributor.advisorSheng-Lung Huangen
dc.contributor.authorNICQUE Guillaumezh_TW
dc.contributor.authorNICQUE Guillaumeen
dc.date.accessioned2025-08-21T16:19:50Z-
dc.date.available2025-08-22-
dc.date.copyright2025-08-21-
dc.date.issued2024-
dc.date.submitted2025-08-05-
dc.identifier.citation[1] K. F. Wall and A. Sanchez, “Titanium sapphire lasers,” Linc. Lab. J., vol. 3, pp. 447-462, 1990.
[2] Andreici Eftimie, E.-L., & Avram, N. M. “Absorption spectra, ligand field parameters and g factors of Cr3+ doped α-Al2O3 laser crystal: ab initio calculations.” Physica Scripta, 2019.
[3] https://www.jasco-global.com/solutions/estimation-of-refractive-index-of-monocrystalline-sapphire-by-polarization-measurement-using-microscopic-spectrophotometer/.
[4] Shirakov, A., Burshtein, Z., Shimony, Y. et al. “Radiative and non-radiative transitions of excited Ti3+ cations in sapphire.” Sci Rep 9, 18810, 2019.
[5] Sorokin, E. “Solid-State Materials for Few-Cycle Pulse Generation and Amplification.” Few-Cycle Laser Pulse Generation and Its Applications, pp. 3-73, 2004.
[6] P. F. Moulton, “Spectroscopic and laser characteristics of Ti:Al₂O₃,” J. Opt. Soc. Am. B, vol. 3, no. 1, pp. 125–133, 1986.
[7] S. C. Wang, “Development and Applications of Glass-clad Ti:Al2O3 Crystal Fiber,” Ph.D. Dissertation, National Taiwan University, Taiwan, 2016.
[8] J. H. Wang, “The study of Ti:sapphire crystal fiber based wavelength swept laser,” M.S. thesis, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 2018.
[9] https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=26
[10] https://spie.org/publications/spie-publication-resources/optipedia-free-optics-information/fg08_p32_fabry-perot_interferometer
[11] https://www.thorlabs.com/newgrouppage9.cfm?objectgroup_id=9021
[12] https://www.fiberoptics4sale.com/blogs/wave-optics/acousto-optic-modulators
[13] Cucinotta, A., Selleri, S., Vincetti, L., & Zoboli, M. “Numerical and experimental analysis of erbium-doped fiber linear cavity lasers.” Optics Communications, 156(4-6), 264–270, 1998.
[14] A. Sennaroglu, “Broadly tunable Cr4+-doped solid-state lasers in the near infrared and visible,” Optical Materials, vol. 11, no. 2–3, pp. 287–295, 1999.
[15] A. Cucinotta, S. Selleri, L. Vincetti, and M. Zoboli, “Design and characterization of erbium-doped fiber linear cavity lasers,” IEEE Photonics Technology Letters, vol. 10, no. 9, pp. 1265–1267, 1998.
[16] Hsiu-Yu Lu “Wavelength-Swept Ring Cavity Ti:sapphire Crystal Fiber Laser” M.S. thesis, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 2023.
[17] Yu-Chan Lin “Study of ultra-broadband Ti:sapphire crystal fiber based wavelength-swept laser” M.S. thesis, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 2022.
[18] https://www.gratinglab.com/Products/Product_Tables/Efficiency/Efficiency.as
[19] Chun-Yi Kuo “The study of high-speed ultra-broadband Ti:sapphire crystal fiber based wavelength swept laser” M.S. thesis, Graduate Institute of Photonics and Optoelectronics, National Taiwan University, 2020.
[20] Slepneva, Svetlana & Kelleher, Bryan & O’Shaughnessy, B. & Hegarty, Stephen & Vladimirov, A. & Huyet, Guillaume. (2013). “Dynamics of Fourier domain mode-locked lasers.” Optics Express 21, pp. 19240-19251, 2013
[21] C. Jirauschek, B. Biedermann, and R. Huber, “A theoretical description of Fourier domain mode locked lasers,” J. Opt. Soc. Am. B, vol. 27, no. 4, pp. 702–713, 2010.
[22] A. G. Vladimirov and D. Turaev, “Model for passive mode locking in semiconductor lasers,” Phys. Rev. A, vol. 72, no. 3, 2005.
[23] A. G. Vladimirov, D. Turaev, and G. Kozyreff, “Delay differential equations for mode-locked semiconductor lasers,” Opt. Lett., vol. 29, pp. 1221–1223, 2004.
[24] H. Haus, “Theory of mode locking with a fast saturable absorber,” IEEE J. Quantum Electron., vol. 11, pp. 736–746, 1975.
[25] G. H. C. New, “Theory of mode locking,” IEEE J. Quantum Electron., vol. 10, no. 2, pp. 115–124, 1974.
[26] B. Tromborg, H. Lassen, and H. Olesen, “Modeling of semiconductor laser dynamics,” IEEE J. Quantum Electron., vol. 30, pp. 939–949, 1994.
[27] U. Bandelow et al., “Impact of dispersion on passively mode-locked semiconductor lasers,” IEEE J. Quantum Electron., vol. 37, pp. 183–192, 2001.
[28] G. P. Agrawal, Nonlinear Fiber Optics, Academic Press, 2001.
[29] P. L. Kelley, I. P. Kaminow, and G. P. Agrawal, Applications of Nonlinear Fiber Optics, Academic Press, 2002.
[30] P. V. Mamyshev and S. V. Chernikov, “Pulse compression in a cascaded fiber system,” Opt. Lett., vol. 15, no. 19, pp. 1076–1078, 1990.
[31] F. M. Mitschke and L. F. Mollenauer, “Discovery of solitons,” Opt. Lett., vol. 11, pp. 659–661, 1986.
[32] J. P. Gordon, “Theory of soliton propagation,” Opt. Lett., vol. 11, pp. 662–664, 1986.
[33] R. H. Stolen et al., “Raman response function of silica fibers,” J. Opt. Soc. Am. B, vol. 6, pp. 1159–1166, 1989.
[34] K. J. Blow and D. Wood, “Theoretical description of self-phase modulation,” IEEE J. Quantum Electron., vol. 25, pp. 2665–2673, 1989.
[35] V. L. Ginzburg and L. D. Landau, “On the theory of superconductivity,” Zh. Eksp. Teor. Fiz., vol. 20, pp. 1064–1082, 1950.
[36] N. Akhmediev and A. Ankiewicz, Dissipative Solitons, Springer, 2005.
[37] P. W. Milonni and J. H. Eberly, Lasers, Wiley, 1988.
[38] CalcWorkshop, “Euler’s Method Table Example.” Available: https://calcworkshop.com/first-order-differential-equations/eulers-method-table/
[39] T. R. Taha and M. J. Ablowitz, “Analytical and numerical aspects of certain nonlinear evolution equations,” J. Comput. Phys., vol. 55, pp. 203–230, 1984.
[40] Q. Chang, E. Jia, and W. Sun, “Wave propagation analysis,” J. Comput. Phys., vol. 148, pp. 397–421, 1999.
[41] K. S. Yee, “Numerical solution of initial boundary value problems involving Maxwell’s equations,” IEEE Trans. Antennas Propag., vol. 14, pp. 302–307, 1966.
[42] P. M. Goorjian and Y. Silberberg, “FDTD simulations of ultrafast optical phenomena,” J. Opt. Soc. Am. B, vol. 14, pp. 3523–3531, 1997.
[43] ZHNotes, “2D FDTD Simulation of Laser Propagation.” Available: https://zhnotes.wordpress.com/2013/08/10/two-dimensional-fdtd-simulation-of-laser-pulse-propagating-in-vacuum/
[44] H. A. Haus, “Mode-locking of lasers,” IEEE J. Sel. Top. Quantum Electron., vol. 6, no. 6, pp. 1173–1185, 1996.
[45] J. M. Soto-Crespo and N. Akhmediev, “Stability of pulselike solutions in Ginzburg-Landau equation,” Phys. Rev. E, vol. 48, no. 6, pp. 4710–4715, 1993.
[46] H. A. Haus, “Theory of mode locking with a fast saturable absorber,” J. Appl. Phys., vol. 46, no. 7, pp. 3049–3058, 1975.
[47] N. Akhmediev and A. Ankiewicz, “Dissipative Solitons in the Complex Ginzburg-Landau and Swift-Hohenberg Equations,” Lecture Notes in Physics, vol. 661, Springer, 2005.
[48] F. X. Kärtner, Ultrafast Optics, LibreTexts, Ch. 6.2.
[49] A. E. Siegman, Lasers, University Science Books, 1986.
[50] R. Huber, M. Wojtkowski, and J. G. Fujimoto, “Fourier domain mode locking: A new laser regime,” Opt. Express, vol. 14, no. 8, pp. 3225–3237, 2006.
[51] T. Klein et al., “Megahertz OCT for retinal imaging,” Opt. Express, vol. 19, no. 4, pp. 3044–3062, 2011.
[52] C. Jirauschek, B. Biedermann, and R. Huber, “Theory of Fourier domain mode locked lasers,” J. Opt. Soc. Am. B, vol. 27, no. 4, pp. 702–713, 2010.
[53] S. Slepneva et al., “Dynamics of Fourier domain mode-locked lasers,” Opt. Express, vol. 21, pp. 12966–12989, 2013.
[54] Corning, “SMF-28 Ultra Optical Fiber Product Info.” Available: https://www.corning.com/media/worldwide/coc/documents/Fiber/SMF-28-Ultra-Optical-Fiber-Product-Information.pdf
[55] K. Tamura et al., “Noise-like pulse generation in soliton lasers,” Opt. Lett., vol. 18, no. 13, pp. 1080–1082, 1993.
[56] J. Liu, J. Liu, and F. Gan, “Ti:sapphire lasers: Fundamentals and applications,” Optics & Laser Technology, vol. 31, no. 8, pp. 525–532, 1999.
[57] A. E. Siegman, Lasers, University Science Books, 1986.
[58] F. X. Kärtner (Ed.), Few-Cycle Laser Pulse Generation and Its Applications, Springer, 2004.
[59] R. Huber, D. C. Adler, and J. G. Fujimoto, “Buffered Fourier domain mode locking,” Opt. Lett., vol. 31, pp. 2975–2977, 2006.
[60] S. Karpf et al., “Time-encoded stimulated Raman scattering,” Nat. Commun., vol. 8, Article 215, 2017.
[61] Roditi International, “Ti:Sapphire Crystals.” Available: https://www.roditi.com/Laser/Ti_Sapphire.html
[62] K. Sato, M. Matsuoka, and T. Fukuda, “Excited-state absorption of Ti³⁺ in sapphire,” J. Appl. Phys., vol. 62, no. 2, pp. 467–470, 1987.
[63] D. Huang et al., “Optical coherence tomography,” Science, vol. 254, no. 5035, pp. 1178–1181, 1991.
[64] A. F. Fercher et al., “OCT—principles and applications,” Rep. Prog. Phys., vol. 66, no. 2, pp. 239–303, 2003.
[65] W. Drexler and J. G. Fujimoto, Optical Coherence Tomography: Technology and Applications, 2nd ed., Springer, 2015.
[66] S. H. Yun et al., “High-speed optical frequency-domain imaging,” Opt. Express, vol. 11, no. 22, pp. 2953–2963, 2003.
[67] M. Wojtkowski, “High-speed optical coherence tomography: basics and applications,” Appl. Opt., vol. 49, pp. D30–D61, 2010.
[68] W. Drexler and J. G. Fujimoto, “OCT: Technology and Applications,” 2nd ed., Springer, pp. 3–94, 865–911, 2015.
[69] J. M. Liu, Nonlinear Optics: Principles and Applications, Cambridge University Press, 2005.
[70] A. Taflove and S. C. Hagness, Computational Electrodynamics: The FDTD Method, 3rd ed., Artech House, 2005.
[71] J. Crank and P. Nicolson, “Numerical evaluation of heat-conduction solutions,” Proc. Camb. Philos. Soc., vol. 43, no. 1, pp. 50–67, 1947.
[72] A. R. Mitchell and D. F. Griffiths, The Finite Difference Method in Partial Differential Equations, Wiley, 1980.
[73] A. Taflove and S. C. Hagness, Computational Electrodynamics: The FDTD Method, 3rd ed., Artech House, 2005.
[74] W. Wieser et al., “Multi-megahertz OCT: 3D imaging at 20 million A-scans,” Biomed. Opt. Express, vol. 5, no. 9, pp. 2963–2977, 2014.
[75] X. Liu et al., “Swept-wavelength tunable lasers for OCT,” J. Biomed. Opt., vol. 9, no. 2, pp. 234–242, 2004.
-
dc.identifier.urihttp://tdr.lib.ntu.edu.tw/jspui/handle/123456789/99086-
dc.description.abstract傅立葉域鎖模雷射(FDML)是高速光學同調斷層掃描(OCT)的重要進展,可在不犧牲光譜解析度的前提下實現超高速成像。我們建立一套基於摻鈦藍寶石晶體光纖之 FDML 雷射的時域模擬,評估其作為下一代 OCT 寬頻波長掃描光源之可行性。結合摻鈦藍寶石具備的寬增益頻寬與極快恢復時間,以及晶體光纖優異的散熱管理,本研究構建完整數值模型,納入增益動態與非線性傳播。
本研究之核心為模組化腔體模型: (1) 摻鈦藍寶石增益介質以含飽和增益與頻譜濾波之Ginzburg–Landau Equation描述;(2) 被動腔體光纖,以相似方程納入色散與自相位調變;(3) 掃頻濾波器元件,於共動座標系中以動態高斯帶通濾波器實作。此架構可物理地解析增益整形、頻譜濾波與非線性傳播之交互作用。
我們先對腔內元件(繞射光柵、法布里–佩羅濾波器、聲光調變器, AOM)進行特性建模,並模擬連續波(CW)與掃頻運作。傳播以分步傅立葉法(SSFM)求解,並由放大自發輻射(ASE)啟動以呈現自啟動行為,同時連結小信號增益係數與實際泵浦功率。
另引入共動掃頻濾波器與失諧策略 Δf:同時調變掃頻角頻率ω₀與濾波器中心頻率,以改善既有 FDML 模型之穩定性限制。我們重現典型 FDML 行為:漸進式自啟動、脈衝與掃頻同步,以及無失諧時可達廣頻光譜展演;引入失諧後,則觀察到頻寬縮減、振盪包絡與相位調變等現象。結果顯示,FDML摻鈦藍寶石雷射的動態輸出並非持續單一波長掃描,而是時域局部化脈衝,每個脈衝具狹窄瞬時線寬,並與掃頻濾波器同步;時間平均後呈現寬頻輸出,然任一時刻僅釋出狹窄頻段,為 FDML 之典型特徵。
綜上,本研究建立泵浦功率、增益閾值、失諧量與光譜輸出之定量關聯,並提供經驗證之模擬框架,可支援以摻鈦藍寶石增益介質開發超寬頻 FDML 雷射之設計與最佳化。
zh_TW
dc.description.abstractFourier Domain Mode-Locked (FDML) lasers represent a key advancement for high-speed Optical Coherence Tomography (OCT), enabling ultrafast imaging without sacrificing spectral resolution. In this work, we develop a time-domain simulation of an FDML laser based on a Ti:sapphire crystal fiber, aiming to explore its potential as a broadband, wavelength-swept light source for next-generation OCT systems. Leveraging the broad gain bandwidth and ultrafast recovery time of Ti:sapphire, as well as the thermal management advantages of a crystal fiber geometry, we construct a complete numerical model that incorporates both gain dynamics and nonlinear field propagation.
A central innovation of this study is the modular architecture of the simulation, in which the FDML cavity is modeled through three distinct components: (1) a Ti:sapphire gain medium, governed by a Ginzburg–Landau equation with saturable gain and spectral bandwidth filtering; (2) a passive cavity fiber, described by a similar equation incorporating dispersion and self-phase modulation; and (3) a lumped sweeping filter element, implemented in a co-moving frame via a dynamically tuned Gaussian bandpass filter. This framework enables physically interpretable modeling of the interplay between gain shaping, spectral filtering, and nonlinear propagation.
We first characterize the gain medium and cavity elements—including diffraction gratings, Fabry–Perot filters, and acousto-optic modulators—and simulate both continuous-wave and wavelength-swept laser regimes. The propagation is solved using a Split-Step Fourier Method with noise self-starting from amplified spontaneous emission (ASE) and realistic values for gain saturation and dispersion.
Another key contribution of this work is the implementation of a co-moving sweeping filter and a new detuning strategy: by modulating both the sweeping frequency ω₀ and the filter’s spectral center with a detuning factor Δf, we resolve stability limitations encountered in earlier FDML models. Linking our small-signal gain coefficient to realistic pump power, our simulation reproduces typical FDML behavior: including gradual self-starting, pulse synchronization to the sweep, and broadband spectral evolution up to 74 THz in the non-detuned case. Upon introducing detuning, we observe a reduction in bandwidth, oscillatory signal envelopes, and phase modulation, in agreement with theoretical expectations and prior experimental observations. Based on our simulation results, the dynamic spectral output of the FDML Ti:sapphire laser does not correspond to a continuously swept single-wavelength output. Instead, the laser exhibits time-localized pulses, each containing a narrow instantaneous linewidth (~0.5-0.8 GHz), synchronized with the sweeping filter. This confirms a pulsation-like behavior in both time and frequency domains, consistent with experimentally observed FDML laser dynamics. The output spectrum appears broadband when averaged over time, but at any given moment, only a narrow portion of the spectrum is emitted, a hallmark of FDML operation.
These results establish a quantitative link between pump power, gain threshold, detuning, and spectral output, and provide a validated simulation framework for the design of ultra-broadband FDML lasers using Ti:sapphire gain media.
en
dc.description.provenanceSubmitted by admin ntu (admin@lib.ntu.edu.tw) on 2025-08-21T16:19:50Z
No. of bitstreams: 0
en
dc.description.provenanceMade available in DSpace on 2025-08-21T16:19:50Z (GMT). No. of bitstreams: 0en
dc.description.tableofcontents中文摘要 ii
ABSTRACT iv
TABLE OF CONTENT vi
LIST OF FIGURES ix
LIST OF TABLES xv
Chapter 1 Introduction and Research Motivation 1
1.1 Introduction to Optical Coherence Tomography 1
1.2 Introduction to Fourier Domain Mode Locked (FDML) Laser 3
Chapter 2 Characterization of Glass-Clad Ti:sapphire Crystal Fiber and Laser 6
2.1 Basic Characteristics of Ti:sapphire Crystals 7
2.2 Optical Properties of Ti:sapphire Crystals 10
2.2.1 Crystal Emission and Absorption 10
2.2.2 Crystal Fluorescence Lifetime 13
2.2.3 Crystal Fiber Propagation Losses 16
2.3 Optical Components of a Ti:sapphire Crystal Fiber Laser 18
2.3.1 Diffraction Gratings 19
2.3.2 Fabry–Pérot Filter 20
2.3.3 Acousto-Optic Modulators 23
Chapter 3 Modeling of Ti:sapphire Crystal Fiber and Laser 26
3.1 Modeling of Ti:sapphire Crystal 26
3.1.1 Energy Levels and Rate Equations 27
3.1.2 Distributive Model for Ti:sapphire Crystal Fiber 30
3.2 Continuous-wave Ti:sapphire Laser Model using the Distributive Model 34
3.3 Ti:sapphire Swept Laser Model using the Distributive Model 45
3.3.1 Theoretical Models of Linear and Ring Cavity Swept laser 46
3.3.2 Result Analysis of the Theoretical Swept Laser Simulation and Experimental Data Comparison 52
Chapter 4 Theoretical Models for Electromagnetic Field Propagation inside a Laser Cavity and Non-linear Medium 61
4.1 Different Derivations of the Maxwell Equations to Simulate Field Propagation 63
4.1.1 The Delay Differential Equation 63
4.1.2 The Nonlinear Schrödinger Equation 68
4.1.3 The Ginzburg-Landeau Equation 71
4.2 Signal Amplification Models : Gain bandwidth and saturation 72
4.3 Numerical methods to Solve the Propagation Equations 76
4.3.1 Euler’s Method 76
4.3.2 Finite Difference Time Domain Method 78
4.3.3 Split-Step Fourier Method 80
4.4 Mode-Locked Simulation based on the Delay Differential Equation using the Euler Method 83
4.5 Mode-Locked Simulation based on the Nonlinear Schrödinger Equation using Split-Step Fourier Method 87
Chapter 5 Ti:sapphire Crystal Fiber FDML Laser Simulation 100
5.1 Implementation of the Sweeping Filter 101
5.2 Complete FDML Laser Simulation Model 104
5.2.1 Initial Parameters, Time and Frequency Grids 107
5.2.2 ASE Implementation and Noise Self-Start Simulation 110
5.2.3 Sweeping Filter and Propagation Equation Interplay 112
5.3 Results Analysis and Discussion 119
5.3.1 Analysis of the Intensity Evolution in Time and Frequency Domain 119
5.3.2 Quantitative Comparison with Existing Models and Experiments 130
5.4 Detuning between the Sweeping Filter Speed and Round-Trip Time 137
5.4.1 Implementation of the Detuning 137
5.4.2 Analysis of the Detuning Effect on the Signal 139
Chapter 6 Conclusion and Future Work 143
6.1 Conclusion 143
6.2 Future Work 145
REFERENCES 148
-
dc.language.isoen-
dc.subjectFDML 雷射zh_TW
dc.subject摻鈦藍寶石晶體光纖zh_TW
dc.subject光學同調斷層掃描zh_TW
dc.subjectGinzburg–Landau equationzh_TW
dc.subject寬頻雷射模擬zh_TW
dc.subject掃頻濾波器動態zh_TW
dc.subjectOCTen
dc.subjectFDML laseren
dc.subjectsweeping filter dynamicsen
dc.subjectbroadband laser simulationen
dc.subjectGinzburg–Landau equationen
dc.subjectTi:sapphire crystal fiberen
dc.title用於光學同調斷層掃描的摻鈦藍寶石晶體光纖之FDML雷射動態建模zh_TW
dc.titleModeling FDML Dynamics in Ti:sapphire Crystal Fiber Laser for OCTen
dc.typeThesis-
dc.date.schoolyear113-2-
dc.description.degree碩士-
dc.contributor.oralexamcommittee李穎玟;李翔傑zh_TW
dc.contributor.oralexamcommitteeYing-Wen Lee;Hsiang-Chieh Leeen
dc.subject.keywordFDML 雷射,摻鈦藍寶石晶體光纖,光學同調斷層掃描,Ginzburg–Landau equation,寬頻雷射模擬,掃頻濾波器動態,zh_TW
dc.subject.keywordFDML laser,Ti:sapphire crystal fiber,OCT,Ginzburg–Landau equation,broadband laser simulation,sweeping filter dynamics,en
dc.relation.page154-
dc.identifier.doi10.6342/NTU202503061-
dc.rights.note同意授權(限校園內公開)-
dc.date.accepted2025-08-07-
dc.contributor.author-college電機資訊學院-
dc.contributor.author-dept光電工程學研究所-
dc.date.embargo-lift2025-08-22-
顯示於系所單位:光電工程學研究所

文件中的檔案:
檔案 大小格式 
ntu-113-2.pdf
授權僅限NTU校內IP使用(校園外請利用VPN校外連線服務)
5.1 MBAdobe PDF
顯示文件簡單紀錄


系統中的文件,除了特別指名其著作權條款之外,均受到著作權保護,並且保留所有的權利。

社群連結
聯絡資訊
10617臺北市大安區羅斯福路四段1號
No.1 Sec.4, Roosevelt Rd., Taipei, Taiwan, R.O.C. 106
Tel: (02)33662353
Email: ntuetds@ntu.edu.tw
意見箱
相關連結
館藏目錄
國內圖書館整合查詢 MetaCat
臺大學術典藏 NTU Scholars
臺大圖書館數位典藏館
本站聲明
© NTU Library All Rights Reserved