多次再入射共振腔是由一對球面鏡所組成，架構簡單體積小而且光路校準容易的雷射架構。環形共振腔可消除雷射中的空間燒孔效應與綠光問題，並產生單縱模雷射。非平面與平面環形共振腔的特性，如多次再入射條件與共振腔穩定度皆已分析，依據多次再入射條件，我們已經成功建構出多次再入射非平面與平面環型雷射，其實驗腔長與模擬腔長誤差小於1.2%。
本論文以Yb3+:YAG作為雷射晶體，與Nd3+:YAG相較，Yb3+:YAG有許多優勢，例如，Yb3+離子掺雜濃度高，量子缺陷(幫浦光子與雷射光子的能量差異)低，上能階生命期長，輻射頻譜與吸收頻譜皆寬。然而Yb3+:YAG晶體屬於準三能階雷射，這使得溫度控制對雷射效率十分重要。
以Ti:sapphire雷射幫浦Yb3+:YAG所產生的連續波環型雷射，其雷射斜率效率對塊材之Yb3+:YAG可達50.3%，對Yb3+:YAG晶體光纖可達54.7%，實驗中我們觀察到了Yb3+:YAG晶體中熱負載對雷射的影響，並與Nd3+:YAG雷射作比較。加入飽和吸收體Cr4+:YAG後，可得到Q開關雷射輸出，由於環形共振腔的特殊架構，增益介質所產生的自發輻射雜訊對飽和吸收體的居量反轉影響較小，所以時序擾動大約只有11%，此時環形Q開關雷射的脈衝寬度大約是33 ns。
以雷射二極體幫浦Yb3+:YAG所產生的連續波環型雷射，其體積小，但雷射斜率效率僅達25%，這是因為當高能量雷射二極體以端面形式來幫浦環形共振腔時，遭遇到模態不匹配與晶體熱負載量大兩個挑戰；其中模態不匹配可以靠共振腔的設計來解決，而雷射加熱提拉生長法所產生的Yb3+:YAG晶體光纖，面積小可以改善散熱，我們已成功得到Yb3+:YAG晶體光纖雷射並與Yb3+:YAG晶體雷射作比較。就我們所知，這是文獻中第一次以Yb3+:YAG作出環型雷射，也是第一次做出Yb3+:YAG晶體光纖雷射。

The multi-pass ring cavity was constructed using only a pair of identical spherical mirrors, which is compact and can easily be aligned. The spatial hole burning effect and green problem can be eliminated in these ring cavities that can be applied to generate a single frequency laser. The characteristics of multi-pass non-planar and planar multi-pass ring cavities were analyzed, such as the reentrant conditions and cavity stability. The multi-pass ring lasers were successfully demonstrated by the reentrant condition simulations, the cavity length error between experimental result and simulation value were below 1.2%.
Yb3+:YAG was used as the gain medium in this dissertation, it has many advantages compared with that of Nd3+:YAG. Such as high doping concentration, low quantum defect, long upper state lifetime, broad emission bandwidth and its wide absorption band. However, the quasi-three-level nature of Yb3+:YAG makes temperature control crucial for laser performance.
A Ti:sapphire laser pumped Yb3+:YAG bulk crystal multi-pass continuous-wave ring laser was demonstrated with a slope efficiency of 50.3%, and a Yb3+:YAG crystal fiber ring laser was demonstrated with a slope efficiency of 54.7%. The thermal load in Yb3+:YAG was observed and compared with that of Nd3+:YAG. The passively Q-switched operation was obtained by a Cr4+:YAG saturable absorber. Due to the ring cavity configuration, the spontaneous noise from gain medium perturbs the population difference of the saturable absorber was reduced so that the timing jitter of the repetition period was restrained to around 11% while 33 ns pulses were obtained.
A compact diode-pumped continuous-wave ring cavity with 25.0% slope efficiency was presented. Two main challenges are noticed in the high power laser diode end pumped configuration, mode-matching difficulty and huge heat load. The mode-matching problem can be solved by an appropriate cavity design, the laser-heated pedestal growth (LHPG) method was used to growth Yb3+:YAG crystal fiber with small surface to improve the heat dissipation. The fiber crystal laser was successfully generated and compared with that of bulk crystal. To our knowledge, this is the first demonstration of a Yb3+:YAG ring laser, and also the first demonstration of Yb3+:YAG crystal fiber ring laser.

Table of Contents
中文摘要………………………..………………………………………… i
Abstract ………………………………………………………………….. ii
Table of Contents………………………………………………………… iii
List of Tables……………………………………………………………... v
List of Figures……………………………………………………………. vi

Chapter 1 Introduction…………….…….……………………………… 1

Chapter 2 Multi-pass ring cavity and gain medium…………………… 4
2.1 Non-planar and planar ring cavities ………………………….. 4
2.2 Yb3+:YAG………………..…………………………………… 14
2.3 Requirement of pump laser for mode matching………………. 18

Chapter 3 Optical coating………...……………………………………... 21
3.1 Crystal preparation.….…………..……………………………. 21
3.2 Electron beam evaporation…...…………………………..…… 24
3.2.1 Electron beam system …………………………………... 24
3.2.2 Wideband optical monitoring system …..………………. 27
3.2.3 Principle of wideband optical monitoring ……………… 30
3.2.4 TiO2 and SiO2 deposition……………………..…………. 34
3.3 Design and result on laser mirrors and Yb:YAG ……………... 38

Chapter 4 Continuous-wave Yb:YAG ring laser…..…………………... 42
4.1 Cooling system of Yb:YAG…...…..…………………………... 42
4.2 Yb3+:YAG absorption measurement…………………………... 44
4.3 Performance of continuous-wave Yb:YAG ring lasers……….. 46
4.3.1 Slope efficiency and threshold………………………….. 46
4.3.2 Polarization and path length difference…………………. 51
4.4 Fundamental characteristics measurements of ring cavity……. 53
4.4.1 Reentrant condition …………………………………….. 53
4.4.2 Cavity detuning tolerance ………………………………. 56
4.4.3 Polarization of the ring laser …………………………… 58

Chapter 5 Q-switched Yb:YAG ring laser……………………………… 60
5.1 Passively Q-switched multi-pass ring laser..….………………. 60
5.2 Timing jitter…………………………………………………… 63
5.3 Laser diode-pumped Yb:YAG ring lasers…………………….. 64
5.3.1 Laser diode measurement……………………………….. 64
5.3.2 Mode matching consideration in (3, 1) ring laser………. 68
5.3.3 Continuous-wave planar N=2 ring laser………………… 72
5.3.4 Passively Q-switched planar N=2 ring laser……………. 73
5.3.5 Yb:YAG crystal fiber laser……………………………… 75

Chapter 6 Conclusions and future work……………………………….. 78
6.1 Conclusions…………………………………………………… 78
6.2 Future work…………………………………………………… 80

References………………………………………………………………... 82
Biography………………………………………………………………… 89
Publication List…………………………………………………………... 90

List of Tables
Table 2.1 Beam paths in planar ring cavities with R=80 mm and d=10 mm.. 7
Table 2.2 The beam path for N is 3 of planar and non-planar ring cavity…...
8
Table 2.3 Advantages of planar and non-planar ring cavities……………….. 13
Table 2.4 Physical characteristics of YAG………………………………..… 16
Table 2.5 Optical characteristics of Yb3+:YAG and Nd3+:YAG…………….. 16
Table 3.1 SiC grit size (USA)………………………………………………. 22
Table 3.2 The grinding process of Yb:YAG………………………………… 22
Table 3.3 The polishing process of Yb:YAG………………………………..
22
Table 3.4 The cleaning process of Yb:YAG………………………………… 23
Table 3.5 Specification of JEBG-203UB6S (E-beam system)……………… 25
Table 3.6 The specification of optical monitoring system…………………..
29
Table 3.7 Characteristics of TiO2 and SiO2…………………………………. 34
Table 3.8 The specification of targets………………………………………. 34
Table 3.9 The evaporation parameters of TiO2 and SiO2……………………
35
Table 3.10 The AR design for Yb:YAG……………………………………… 40
Table 4.1 Specifications of TE-cooler……………………………………….
43
Table 4.2 Theoretical and experimental cavity lengths……………………... 55
Table 6.1 The nonlinear refractive indices in Kerr media…………………...
81





List of Figures
Fig. 2.1 Multi-pass ring laser set-up……………………………………….... 4
Fig. 2.2 Beam path in the 2-point planar ring cavity. O2 is the spherical center of M2………………………………………………………....
5
Fig. 2.3 Normalized cavity lengths (L/R) for N=2 and N=3 planar ring cavities……………………………………………………………....
6
Fig. 2.4 Normalized lengths of planar and non-planar ring cavities……....... 8
Fig. 2.5 Beam paths in the planar ring cavities when N is (a) even and (b) odd…………………………………………………………………..

10
Fig. 2.6 Stability analyses in (a) x-direction and (b) y-direction for the empty planar N=2-7 ring cavities with R=80 mm………….……....

11
Fig. 2.7 Stabilities with gain media of various effective thicknesses of planar N=2 ring cavities. Stability analyses in (a) x-direction and (b) y-direction with the gain medium at the center of the cavity. Stability analyses in (c) x-direction, and (d) y-direction with the gain medium on the side arm of the cavity…………………………



12
Fig. 2.8 Stability analyses in (a) x-direction and (b) y-direction for various effective thicknesses of gain medium placed on one side arm of the beam path in the planar N=3 ring cavity………….…………...……

13
Fig. 2.9 Energy level diagram of Yb3+:YAG……………….………….….…
14
Fig. 2.10 The absorption and emission spectra of Yb3+:YAG at 300K…..…… 17
Fig. 2.11 The dependence of cavity length and mode size on R of the cavity mirrors (I/C and O/C represent the input and output couplers. L100 and W100 are the cavity length and the mode diameter at the cavity center when R equals 100 mm and d0/R equals 0.1)…………….….


19
Fig. 2.12 (a) The relationship of round-trip length and cavity length in ring and linear cavities (R is 100 mm). The number associated with each rhombus mark is the M number of the (N, M) configuration. (b) The mode diameter in the ring and linear cavities…….…..…….


20
Fig. 3.1 Schematic of Electron beam system…………………….……..…… 25
Fig. 3.2 Schematic of an E-beam evaporation system…………….…..……..

27
Fig. 3.3 (a) Transmission spectrum of a 1000-nm-thick TiO2 layer with B270 substrate. (b) The time dependent differential transmittance for a monitor wavelength of 500 nm…………………………..……


29
Fig. 3.4 The dependence of transmittance and its variation on optical thickness………………………………………………………….....


30
Fig. 3.5 Ratio method of optical monitoring system. (a) The optical thickness is less than 0.25λ. (b) The optical thickness is larger than 0.25λ………………………………………………………………..


32
Fig. 3.6 Optical monitoring with different k of TiO2 films……….……….... 33
Fig. 3.7 (a) Index, and (b) absorption of TiO2 thin film…………….…….… 36
Fig. 3.8 (a) Index, and (b) absorption of SiO2 thin film………….……….… 36
Fig. 3.9 (a) index, and (b) absorption at 1000 nm of TiO2 thin film with different substrate temperatures……………………….…………....
37
Fig. 3.10 The design and result spectrum on input coupler………..………… 38
Fig. 3.11 The design and result spectrum on output coupler………..……….. 39
Fig. 3.12 The electric field distribution of the output coupler. The vertical bars are the interface between high (H) and low (L) indices media...
39
Fig. 3.13 The design and result spectrum on Yb:YAG…………..………….... 40
Fig. 3.14 The spectrum of AR coating before and after test………..……….... 41
Fig. 4.1 TE-cooler…………………………………………………..…….…. 42
Fig. 4.2 The principle of the TE-cooler with a single pair P-type and N-type semiconductor……………………………………….…….………..
43
Fig. 4.3 Absorption spectrum of the 20-at.% doped Yb3+:YAG….……......... 44
Fig. 4.4 Absorption (a) coefficient and (b) bandwidth of the 20-at.%-doped Yb3+:YAG as a function of temperature………………………….....

45
Fig. 4.5 The Yb:YAG ring laser set-up. HWP and PBS stand for half-wave plate and polarization beam splitter, respectively……......................
46
Fig. 4.6 The (2, 1) ring laser performance as a function of temperature…..... 47
Fig. 4.7 The laser power as a function of pump wavelengths around (a) 941 nm and (b) 969 nm……………………………………..……...........
47
Fig. 4.8 (a) Absorption coefficient and absorption depth of the 20-at.%-doped Yb:YAG as a function of wavelength. (b) Laser slope efficiency and threshold as a function of the absorption depth/crystal length…………………………………………………


48
Fig. 4.9 Laser performance with various round-trip transmittances……….... 49
Fig. 4.10 The performance of the Ti:sapphire laser-pumped planar N=2 ring laser, with 50-mm length mount…………………………………….
50
Fig. 4.11 The performance of the Ti:sapphire laser-pumped (2, 1) ring laser, with 20-mm length mount…………………………………………..
50
Fig. 4.12 The polarization measurements of the non-planar (2, 1) and planar N=2 ring lasers……………………………………………………...
51
Fig. 4.13 The longitudinal mode beat frequencies of counter propagating beams in the Yb:YAG (2, 1) ring laser……………………………...
52
Fig. 4.14 Multi-pass ring laser setup. I/C and O/C denote the input and output couplers……………………………………………………....
53
Fig. 4.15 Laser output beam patterns for various cavity lengths for R=80 mm output couplers. A side view for the triangular beam path is shown in the upper-left corner……………………………………………...

54
Fig. 4.16 Cavity detuning characteristics of (a) Non-planar (2, 1), (b) non-planar (3, 1), and (c) planar N=3 ring cavity lasers…………....
56
Fig. 4.17 Polarization measurements for (a) non-planar (2, 1), (b) non-planar (3, 1), (c) planar N=2, and (d) planar N=3 ring cavities; ‘a’ and ‘b’ are the lengths of long and short axes of the polarization ellipse, respectively………………………………………………………….


58
Fig. 5.1 The simulation and experimental pulse width of the (2, 1) and (3, 1) ring lasers………………………………………………………..

61
Fig. 5.2 Mode diameter (with R=51.83 mm) and normalized round-trip length (with a side shift d0/R=0.06) in the multi-pass (N, 1) ring cavities………………………………………………………………

61
Fig. 5.3 (a) L-I curve, (b) peak power, and (c) repetition rate of Q-switched (2, 1) and (3, 1) ring lasers. (d) Oscilloscope trace of Q-switched (3, 1) ring laser pulse………………………………………………..

62
Fig. 5.4 Timing jitter of the multi-pass ring lasers…………………………..
. 63
Fig. 5.5 The laser diode performances of output power and emission wavelength…………………………………………………………..
64
Fig. 5.6 M2 measurement of the laser diode………………………………… 65
Fig. 5.7 The mode diameter measurement of the laser diode……………….. 66
Fig. 5.8 The minimum laser diode beam size in (a) x axis and (b) y axis after an F=15 mm optical element…………………………………..
66
Fig. 5.9 The measurement and simulation of laser diode beam diameter…... 67
Fig. 5.10 The cavity mode diameter simulation……………………………… 68
Fig. 5.11 (a) set-up and (b) laser output pattern of (3, 1) multi-pass ring laser. 69
Fig. 5.12 (a) Slope efficiency and (b) threshold in (3, 1) multi-pass ring laser with various round-trip transmittances……………………………..
69
Fig. 5.13 The L-I curve of (3, 1) multi-pass ring laser……………………….. 70
Fig. 5.14 The relationship of round-trip transmittance and output power of (3, 1) ring laser……………………………………………………...
70
Fig. 5.15 The L-I curve of diode-pumped planar N=2 ring laser…………….. 72
Fig. 5.16 The L-I curve of passively Q-switched planar N=2 ring laser……... 73
Fig. 5.17 The pulse width measurement of planar N=2 Q-switched ring laser. 73
Fig. 5.18 The self-Q-switched-like behavior measurement…………………... 74
Fig. 5.19 The L-I curve of diode-pumped Yb:YAG crystal fiber laser………. 76
Fig. 5.20 The L-I curve of Ti:sapphire laser pumped ring laser with Yb:YAG bulk and crystal fiber………………………………………………..
77
Fig. 6.1 The refractive index of Yb:YAG…………………………………… 81

[1.1] D. Chen, C. L. Fincher, D. A. Hinkley, R. A. Chodzko, T. S. Rose, and R. A. Fields, “Semimonolithic Nd:YAG ring resonator for generating cw single-frequency output at 1.06 um,” Optics Letters 20, 1283 (1995).
[1.2] T. J. Kane and R. L. Byer, “Monolithic unidirectional single-mode Nd:YAG ring laser,” Optics Letters 10, 65 (1985).
[1.3] K. I. Martin, W. A. Clarkson, and D. C. Hanna, “3W of single-frequency doubling of a diode-bar-pumped Nd:YAG ring laser,” Optics Letters 21, 875 (1996).
[1.4] H. Z. Cheng, P. L. Huang, S. L. Huang, and F. J. Kao, “Reentrant 2-mirror ring resonator for generation of a single-frequency green laser,” Optics Letters 25, 542 (2000).
[1.5] S. L. Huang, Y. H. Chen, P. L. Huang, J. Y. Yi, and H. Z. Cheng, “Multi-reentrant nonplanar ring laser cavity,” IEEE Journal of Quantum Electronics 38, 1301 (2002).
[1.6] A. Sennaroglu, A. M. Kowalevicz, Jr., E. P. Ippen, and J. G. Fujimoto, “Compact femtosecond lasers based on novel multipass cavities,” IEEE Journal of Quantum Electronics 40, 519 (2004).
[1.7] J. Y. Yi and S. L. Huang, “Planar multipass ring laser cavity,” Japanese Journal of Applied Physics 44, 1272 (2005).
[1.8] P. L. Huang, C. R. Weng, H. Z. Cheng, and S. L. Huang, “A passively Q-switched laser constructed by a two-mirror reentrant ring cavity,” Japanese Journal of Applied Physics 40, L508 (2001).
[1.9] W. F. Krupke, “Ytterbium solid-state lasers-The first decade,” IEEE Journal on Selected Topics in Quantum Electronics 6, 1287 (2000).
[1.10] F. D. Patel, E. C. Honea, J. Speth, S. A. Payne, R. Hutcheson, and R. Equall, “Laser demonstration of Yb3Al5O12 (YbAG) and materials properties of highly doped Yb:YAG,” IEEE Journal of Quantum Electronics 37, 135 (2001).


[1.11] A. Giesen, H. Hügel, A. Voss, K. Witting, U. Brauch, and H. Opower, “Scalable concept for diode-pumped high-power solid-state lasers,” Applied Physics B 58, 365 (1994).
[1.12] D. J. Ripin, J. R. Ochoa, R. L. Aggarwal, and T. Y. Fan, “165-W cryogenically cooled Yb:YAG laser,” Optics Letters 9, 2154 (2004).
[1.13] J. Dong, M. Bass, Y. Mao, P. Deng, and D. Gan, “Dependence of the Yb3+ emission cross section and lifetime on temperature and concentration in yttrium aluminum garnet,” Journal of the Optical Society of America. B 20, 1975 (2003).
[1.14] C. Hönninger, R. Paschotta, M. Graf, F. Morier-Genoud, G. Zhang, M. Moser, S. Biswal, J. Ness, A. Braun, G. A. Mourou, I. Johannsen, A. Giesen, W. Seeber, and U. Keller, “Ultrafast ytterbium-doped bulk lasers and laser amplifiers,” Applied Physics B 69, 3 (1999).
[1.15] F. Brunner, R. Paschotta, J. Aus der Au, G. J. Spühler, F. Morier-Genoud, R. Hövel, M. Moser, S. Erhard, M. Karszewski, A. Giesen, and U. Keller, “Widely tunable pulse durations from a passively mode-locked thin-disk Yb:YAG laser,” Optics Letters 26, 379 (2001).
[1.16] C. Hönninger, G. Zhang, U. Keller, and A. Giesen, “Femtosecond Yb:YAG laser using semiconductor saturable absorbers,” Optics Letters 20, 2402 (1995).
[1.17] J. Aus der Au, G. J. Spühler, T. Südmeyer, R. Paschotta, R. Hövel, M. Moser, S. Erhard, M. Karszewski, A. Giesen, and U. Keller, “16.2-W average power from a diode-pumped femtosecond Yb:YAG thin disk laser,” Optics Letters 25, 859 (2000).
[1.18] E. Innerhofer, T. Südmeyer, F. Brunner, R. Häring, A. Aschwanden, R. Paschotta, C. Hönninger, M. Kumkar, and U. Keller, “60-W average power in 810-fs pulses from a thin-disk Yb:YAG laser,” Optics Letters 28, 367 (2003).
[1.19] S. Uemura and K. Torizuka, “Center-wavelength-shifted passively mode-locked diode-pumped ytterbium (Yb): yttrium aluminum garnet (YAG) laser,” Japanese Journal of Applied Physics 44, L361 (2005).

[1.20] U. Brauch, A. Giesen, M. Karszewski, Chr. Stewen, and A. Voss, “Multiwatt diode-pumped Yb:YAG thin disk laser continuously tunable between 1018 and 1053 nm,” Optics Letters 20, 713 (1995).
[1.21] Z. Huang, Y. Huang, M. Huang, and Z. Luo, “Optimizing the doping concentration and the crystal thickness in Yb3+-doped microchip lasers,” Journal of the Optical Society of America B 20, 2061 (2003).

Chapter 2
[2.1] D. C. Brown, “Ultrahigh-average-power diode-pumped Nd:YAG and Yb:YAG lasers,” IEEE Journal of Quantum Electronics 33, 861 (1997).
[2.2] T. Dascalu, T. Taira, and N. Pavel, “100-W quasi-continuous-wave diode radially pumped microchip composite Yb:YAG laser,” Optics Letters 27, 1791 (2002).
[2.3] T. Dascalu, N. Pavel, and T. Taira, “90 W continuous-wave diode edge-pumped microchip composite Yb:Y3Al5O12 laser,” Applied Physics Letters 83, 4086 (2003).
[2.4] Q. Liu, M. Gong, F. Lu, W. Gong, and C. Li, “520-W continuous-wave diode corner-pumped composite Yb:YAG slab laser,” Optics Letters 30, 726 (2005).
[2.5] AGiesen, H. Hügel, A. Voss, K. Witting, U. Brauch, and H. Opower, “Scalable concept for diode-pumped high-power solid-state lasers,” Applied Physics B 58, 365 (1994).
[2.6] T. Kasamatsu, H. Sekita, and Y. Kuwano, “Temperature dependence and optimization of 970-nm diode-pumped Yb:YAG and Yb:LuAG lasers,” Applied Optics 38, 5149 (1999)
[2.7] T. Taira, W. M. Tulloch and R. L. Byer, “Modeling of quasi-three-level lasers and operation of cw Yb:YAG lasers,” Applied Optics 36, 1867 (1997).
[2.8] T. Y. Fan, “Optimizing the efficiency and stored energy in quasi-three-level lasers,” IEEE Journal of Quantum Electronics 28, 2692 (1992).
[2.9] W. P. Risk, “Modeling of longitudinally pumped solid-state lasers exhibiting reabsorption losses,” Journal of the Optical Society of America B 5, 1412 (1988).
Chapter 3
[3.1] N. Kaiser, “Review of the fundamentals of thin-film growth,” Applied Optics 41, 3053 (2002).
[3.2] H.A. Macleod, “Monitoring of Optical Coatings”, Applied Optics 20, 82 (1981).
[3.3] F. J. Van Milligen et al., “Development of an automated scanning monochromator for monitoring thin films,” Applied Optics 24, 1799 (1985).
[3.4] P. Bousquet and E. Pelletier, “Optical thin film monitoring-recent advances and limitations,” Thin Solid Films 77, 165 (1981).
[3.5] C.J. van der Laan, “Optical Monitoring of Nonquarterwave Stacks,” Applied Optics 25, 753 (1986).
[3.6] B. Vidal, A. Fornier, and E. Pelletier, “Optical monitoring of nonquarterwave multilayer filters,” Applied Optics 17, 1038 (1978).
[3.7] B. Vidal, A. Fornier, and E. Pelletier, “Wideband optical monitoring of nonquarter wave multilayer filters,” Applied Optics 18, 3851 (1979).
[3.8] X. Q. Hu, Y. M. Chen, and J. F. Tang, “Apparatus for wideband monitoring of optical coatings and its uses,” Applied Optics 28, 2886 (1989).
[3.9] H. A. Macleod and E. Pelletier, “Error compensation mechanisms in some thin film monitoring systems,” Optica Acta 24, 907 (1977).
[3.10] B. Vidal and E. Pelletier, “Nonquarter wave multilayer filters: optical monitoring with a minicomputer allowing correction of thickness errors,” Applied Optics 18, 3857 (1979).
[3.11] 李正中，“薄膜光學與鍍膜技術”，第三版，藝軒出版社，(2002).
[3.12] D. E. Aspnes, “Optical properties of thin films,” Thin Solid Films 89, 249 (1982).
[3.13] D. Mergel, D. Buschendorf, S. Eggert, R. Grammes, and B. Samset, “Density and refractive index of TiO2 films prepared by reactive evaporation,” Thin Solid Films 371, 218 (2000).
[3.14] W. Heitmann, “Properties if evaporated SiO2, SiOxNy, and TiO2, films,” Applied Optics 10, 2685 (1971).

[3.15]
M. G. Krishna, S. kanakaraju, and S. Mohan, “Structure and composition related properties of titania thin films,” Vacuum 46, 33 (1995).
[3.16] H. W. Lehmann and K. Frick, “Optimizing deposition parameters of electron beam evaporated TiO2 films,” Applied Optics 27, 4920 (1988).
[3.17] H. Selhofer, E. Ritter, and R. Linsbod, “Properties of titanium dioxide films prepared by reactive electron-beam evaporation from various starting materials,” Applied Optics 41, 756 (2002).
[3.18] F. Waibel, E. Ritter, and R. Linsbod, “Properties of TiOx films prepared by electron beam evaporation of titanium and titanium suboxides,” Applied Optics 42, 4590 (2003).
[3.19] J. M. Bennett, E. Pelletier, G. Albrand, J. P. Borgogno, B. Lazarides, C. K. Carniglia, R. A. Schmell, T. H. Allen, T. Tuttle-Hart, K. H. Guenther, and A. Saxer, “Comparison of the properties of titanium dioxide films prepared by various techniques,” Applied Optics 28, 3303 (1989).

Chapter 4
[4.1] C. W. Wang, Y. L. Weng, P. L. Huang, H. Z. Cheng, and S. L. Huang, “Passively Q-switched quasi-three-level laser and its intracavity frequency doubling,” Applied Optics 41, 1075 (2002).
[4.2] A. Yariv, Optical Electronics in Modern Communications. (Oxford University Press, New York, 1997), 5th ed., Chap. 2.2.

Chapter 5
[5.1] Y. Kalisky, C. Labbe, K. Waichman, L. Kravchik, U. Rachum, P. Deng, J. Xu, J. Dong, and W. Chen, “Passively Q-switched diode-pumped Yb:YAG laser using Cr4+-doped garnets,” Optical Materials 19, 403 (2002).
[5.2] J. Dong, P. Deng, Y. Liu, Y. Zhang, J. Xu, W. Chen, and X. Xie, “Passively Q-switched Yb:YAG laser with Cr4+:YAG as the saturable absorber,” Applied Optics 40, 4303 (2001).


[5.3] C. W. Wang, Y. L. Weng, P. L. Huang, H. Z. Cheng, and S. L. Huang, “Passively Q-switched quasi-three level laser and its intracavity frequency doubling,” Applied Optics 41, 1075 (2001).
[5.4] G. Xiao, J. H. Lim, S. Yang, E. Van Stryland, M. Bass, and L. Weichman, “ Z-scan measurement of the ground and excited state absorption cross section of Cr4+ in yttrium aluminum garnets,” IEEE Journal of Quantum Electronics 35, 1086 (1999).
[5.5] S. L. Huang, T. Y. Tsui, C. H. Wang, and F. J. Kao, “Timing jitter reduction of a passively Q-switched laser,” Japanese Journal of Applied Physics 38, L239 (1999).
[5.6] P. L. Huang, C. R. Weng, H. Z. Cheng, and S. L. Huang, “A passively Q-switched laser constructed by a two-mirror reentrant ring cavity,” Japanese Journal of Applied Physics 40, L508 (2001).
[5.7] M. M. Fejer, J. L. Nightingale, G. A. Magel, and R. L. Byer, “Laser-heated miniature pedestal growth apparatus for single-crystal optical fibers,” Review of Scientific Instruments 55, 1791 (1984).
[5.8] C. Y. Lo, P. L. Huang, T. S. Chou, L. M. Lee, T. Y. Chang, S. L. Huang, L. Lin, H. Y. Lin, and F. C. Ho, “Efficient Nd:Y3Al5O12 crystal fiber laser,” Japanese Journal of Applied Physics 41, L1228 (2002).
[5.9] C. Y. Lo, “Growth, characterization, and applications of doped-YAG single-crystal fibers,” Ph.D. Dissertation, National Sun Yat-sen University, Taiwan (2004).

Chapter 6
[6.1] U. Keller, “Recent developments in compact ultrafast lasers,” Nature 424, 831 (2003).
[6.2] U. Keller, “Ultrafast all-solid-state laser technology,” Applied Physics B 58, 347 (1994).
[6.3] D. E. Zelmon, D. L. Small, and R. Page, “Refractive-index measurement of undoped yttrium aluminum garnet from 0.4 to 6.0 um,” Applied Optics 37, 4933 (1998).
[6.4] S. Naumov, E. Sorokin, and I. T. Sorokina, “Directly diode-pumped kerr-lens mode-locked Cr4+:YAG laser,” Optics Letters 29, 1276 (2004).
[6.5] V. Petrov, U. Griebner, D. Ehrt, and W. Seeber, “Femtosecond self mode locking of Yb:fluoride phosphate glass laser,” Optics Letters 22, 408 (1997).
[6.6] H. Liu, J. Ness, and G. Mourou, “Diode-pumped lerr-lens mode-locked Yb:KY(WO4)2 laser,” Optics Letters 26, 1723 (2001).
[6.7] A. A. Lagatsky, A. R. Sarmani, C. T. A. Brown, W. Sibbett, V. E. Kisel, A. G. Selivanov, I. A. Denisov, A. E. Troshin, K. V. Yumashev, N. V. Kuleshov, V. N. Matrosov, T. A. Matrosova, and M. I. Kupchenko, “Yb3+-doped YVO4 crystal for efficient kerr-lens mode-locking in solid-state lasers,” Optics Letters 30, 3234 (2005).
[6.8] S. Uemura and K. Torizuka, “Kerr-lens mode-locked diode-pumped Yb:YAG laser,” Conference on lasers and electro-optics, paper CTuP36, San Francisco, California, USA (2004).
[6.9] A. Major, J. S. Aitchison, P. W. E.Smith, F. Druon, P. Georges, B. Viana, and G. P. Aka, “Z-scan measurements of the nonlinear refractive indices of novel Yb-doped laser crystal host,” Applied Physics B 80, 199 (2005).