[1] [1] ZINKEVICH M. Thermodynamics of rare earth sesquioxides［J］. Progress in Materials Science, 2007, 52(4): 597-647.

[2] [2] TANG M, VALDEZ J A, LU P, et al. A cubic-to-monoclinic structural transformation in the sesquioxide Dy2O3 induced by ion irradiation［J］. Journal of Nuclear Materials, 2004, 328(1): 71-76.

[3] [3] WANG L, PAN Y X, DING Y, et al. High-pressure induced phase transitions of Y2O3 and Y2O3∶Eu3+［J］. Applied Physics Letters, 2009, 94(6): 061921.

[4] [4] HUSSON E, PROUST C, GILLET P, et al. Phase transitions in yttrium oxide at high pressure studied by Raman spectroscopy［J］. Materials Research Bulletin, 1999, 34(12/13): 2085-2092.

[5] [5] PETERS R, PETERMANN K, HUBER G. Growth technology and laser properties of Yb-doped sesquioxides［M］//Crystal Growth Technology. Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, 2010: 267-282.

[6] [6] KOOPMANN P. Thulium- and holmium-doped sesquioxides for 2 μm Lasers ［M］. 1st ed. Aachen: Shaker, 2012

[7] [7] TOKURAKAWA M, SHIRAKAWA A, UEDA K, et al. Ultrashort pulse generation from diode pumped mode-locked Yb3+: sesquioxide single crystal lasers［J］. Optics Express, 2011, 19(4): 2904-2909.

[8] [8] ZELMON D E, NORTHRIDGE J M, HAYNES N D, et al. Temperature-dependent Sellmeier equations for rare-earth sesquioxides［J］. Applied Optics, 2013, 52(16): 3824-3828.

[9] [9] BEIL K, SARACENO C J, SCHRIBER C, et al. Yb-doped mixed sesquioxides for ultrashort pulse generation in the thin disk laser setup［J］. Applied Physics B, 2013, 113(1): 13-18.

[10] [10] MCMILLEN C D, SANJEEWA L D, MOORE C A, et al. Crystal growth and phase stability of Ln∶Lu2O3 (Ln=Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb) in a higher-temperature hydrothermal regime［J］. Journal of Crystal Growth, 2016, 452: 146-150.

[11] [11] MCMILLEN C, THOMPSON D, TRITT T, et al. Hydrothermal single-crystal growth of Lu2O3 and lanthanide-doped Lu2O3［J］. Crystal Growth & Design, 2011, 11(10): 4386-4391.

[12] [12] SPEZIA G. Contribuzioni sperimentali alla cristallogenesi del quarzo ［J］. Atti Accad Sci Torino, 1906, 41: 158-65.

[13] [13] MCMILLEN C D, KOLIS J W. Bulk single crystal growth from hydrothermal solutions［J］. Philosophical Magazine, 2012, 92(19/20/21): 2686-2711.

[14] [14] MC MILLEN C D, KOLIS J W. Hydrothermal single crystal growth of Sc2O3 and lanthanide-doped Sc2O3［J］. Journal of Crystal Growth, 2008, 310(7/8/9): 1939-1942.

[15] [15] MANN M, KOLIS J. Hydrothermal crystal growth of yttrium and rare earth stabilized hafnia［J］. Journal of Crystal Growth, 2010, 312(3): 461-465.

[16] [16] KOLAMBAGE M T K, MCMILLEN C D, MCGUIRE M A, et al. Hydrothermal synthesis of lanthanide rhenium oxides: structures and magnetism of Ln2Re2O7(OH) (Ln=Pr, Nd) and Ln4Re2O11 (Ln=Eu, Tb)［J］. Journal of Solid State Chemistry, 2019, 275: 149-158.

[17] [17] VEBER P, VELZQUEZ M, JUBERA V, et al. Flux growth of Yb3+-doped RE2O3 (RE=Y, Lu) single crystals at half their melting point temperature［J］. CrystEngComm, 2011, 13(16): 5220.

[18] [18] DRUON F, VELZQUEZ M, VEBER P, et al. Laser demonstration with highly doped Yb∶Gd2O3 and Yb∶Y2O3 crystals grown by an original flux method［J］. Optics Letters, 2013, 38(20): 4146-4149.

[19] [19] VEBER P, VELZQUEZ M, GADRET G, et al. Flux growth at 1230 ℃ of cubic Tb2O3 single crystals and characterization of their optical and magnetic properties［J］. CrystEngComm, 2015, 17(3): 492-497.

[21] [21] VEBER P, VELAZQUEZ M, DOUISSARD P A, et al. Flux growth and physical properties characterizations of Y1 866Eu0 134O3 and Lu156Gd041Eu003O3 single crystals［J］. Optical Materials Express, 2015, 6(1): 207.

[22] [22] FORNASIERO L, MIX E, PETERS V, et al. New oxide crystals for solid state lasers［J］. Crystal Research and Technology, 1999, 34(2): 255-260.

[23] [23] FORNASIERO L, MIX E, PETERS V, et al. Czochralski growth and laser parameters of RE3+-doped Y2O3 and Sc2O3［J］. Ceramics International, 2000, 26(6): 589-592.

[24] [24] KRNKEL C, UVAROVA A, HAURAT , et al. Czochralski growth of mixed cubic sesquioxide crystals in the ternary system Lu2O3-Sc2O3-Y2O3［J］. Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials, 2021, 77(4): 550-558.

[25] [25] SUZUKI A, KALUSNIAK S, et al. Spectroscopy and 2.1 μm laser operation of Czochralski-grown Tm3+∶YScO3 crystals［J］. Optics Express, 2022, 30(23): 42762.

[27] [27] LABELLE H E. EFG, the invention and application to sapphire growth［J］. Journal of Crystal Growth, 1980, 50(1): 8-17.

[28] [28] YIN Y R, WANG G J, JIA Z T, et al. Controllable and directional growth of Er∶Lu2O3 single crystals by the edge-defined film-fed technique［J］. CrystEngComm, 2020, 22(39): 6569-6573.

[29] [29] ZHANG M, YIN Y R, ZHANG L, et al. Self-Q-switched Er∶Lu2O3 laser at 2.74 μm［J］. Applied Optics, 2023, 62(6): 1462-1466.

[32] [32] SCHMID F, VIECHNICKI D. Growth of sapphire disks from the melt by a gradient furnace technique［J］. Journal of the American Ceramic Society, 1970, 53(9): 528-529.

[33] [33] PETERS V, BOLZ A, PETERMANN K, et al. Growth of high-melting sesquioxides by the heat exchanger method［J］. Journal of Crystal Growth, 2002, 237/238/239: 879-883.

[34] [34] PETERS V. Growth and spectroscopy of ytterbium-doped sesquioxides ［D］. Hamburg: University of Hamburg, 2001.

[35] [35] PETERS R, KRNKEL C, PETERMANN K, et al. Crystal growth by the heat exchanger method, spectroscopic characterization and laser operation of high-purity Yb: Lu2O3［J］. Journal of Crystal Growth, 2008, 310(7/8/9): 1934-1938.

[36] [36] KOOPMANN P, PETERS R, PETERMANN K, et al. Crystal growth, spectroscopy, and highly efficient laser operation of thulium-doped Lu2O3 around 2 μm［J］. Applied Physics B, 2011, 102(1): 19-24.

[37] [37] LOIKO P A, YUMASHEV K V, SCHDEL R, et al. Thermo-optic properties of Yb∶Lu2O3 single crystals［J］. Applied Physics B, 2015, 120(4): 601-607.

[38] [38] HU K W, ZHENG L L, ZHANG H. Control of interface shape during high melting sesquioxide crystal growth by HEM technique［J］. Journal of Crystal Growth, 2018, 483: 175-182.

[40] [40] PETROV V, PETERMANN K, GRIEBNER U, et al. Continuous-wave and mode-locked lasers based on cubic sesquioxide crystalline hosts[C]. Proceedings of the Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, F May 01, 2006.

[41] [41] PETERMANN K, FORNASIERO L, MIX E, et al. High melting sesquioxides: crystal growth, spectroscopy, and laser experiments ［J］. Optical Materials, 2002, 19(1): 67-71.

[42] [42] ZHENG J Q, LIU C J, YU H H, et al. Single crystal preparation and luminescent properties of Lu2O3∶Eu scintillator by vertical bridgman method［J］. Crystal Research and Technology, 2022, 57(2): 2100120.

[43] [43] FUKABORI A, CHANI V, KAMADA K, et al. Growth of Y2O3, Sc2O3 and Lu2O3 crystals by the micro-pulling-down method and their optical and scintillation characteristics ［J］. Journal of Crystal Growth, 2011, 318(1): 823-830.

[44] [44] NOVOSELOV A, MUN J H, SIMURA R, et al. Micro-pulling-down: a viable approach to the crystal growth of refractory rare-earth sesquioxides［J］. Inorganic Materials, 2007, 43(7): 729-734.

[45] [45] MUN J H, NOVOSELOV A, YOSHIKAWA A, et al. Growth of Yb3+-doped Y2O3 single crystal rods by the micro-pulling-down method［J］. Materials Research Bulletin, 2005, 40(8): 1235-1243.

[46] [46] GUZIK M, PEJCHAL J, YOSHIKAWA A, et al. Structural investigations of Lu2O3 as single crystal and polycrystalline transparent ceramic［J］. Crystal Growth & Design, 2014, 14(7): 3327-3334.

[47] [47] KECK P H, GOLAY M J E. Crystallization of silicon from a floating liquid zone［J］. Physical Review, 1953, 89(6): 1297.

[48] [48] GASSON D B, COCKAYNE B. Oxide crystal growth using gas lasers［J］. Journal of Materials Science, 1970, 5(2): 100-104.

[51] [51] SHI J J, LIU B, WANG Q G, et al. Crystal growth, spectroscopic characteristics, and Judd-Ofelt analysis of Dy∶Lu2O3 for yellow laser［J］. Chinese Physics B, 2018, 27(7): 077802.

[52] [52] ZHUANG L C, FENG H, HUANG S M, et al. The luminescent properties comparison of RE2O3∶Eu(RE=Lu, Y, Sc) with high and low Eu doping concentrations［J］. Journal of Alloys and Compounds, 2019, 781: 302-307.

[53] [53] HOU W T, ZHAO H Y, LI N, et al. Growth and spectroscopic properties of Er∶Lu2O3 crystal grown by floating zone method［J］. Materials Research Express, 2019, 6(6): 066203.

[54] [54] LI S M, ZHANG L H, TAN X J, et al. Growth, structure, and spectroscopic properties of a Tm3+, Ho3+ co-doped Lu2O3 crystal for ~2.1 μm［J］. Optical Materials, 2019, 96: 109277.

[55] [55] LIU W Y, LU D Z, PAN S L, et al. Ligand engineering for broadening infrared luminescence of Kramers ytterbium ions in disordered sesquioxides［J］. Crystal Growth & Design, 2019, 19(7): 3704-3713.

[56] [56] UVAROVA A, KALUSNIAK S, GUGUSCHEV C, et al. OFZ-growth of Yb∶(Sc, Y)2O3 for 1 μm lasers［C］//2021 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). June 21-25, 2021, Munich, Germany. IEEE, 2021: 1.

[57] [57] CHEN G Z, LI S M, FANG Q N, et al. Growth and spectroscopy of Er∶LuYO3 single crystal［J］. Journal of Luminescence, 2021, 239: 118347.

[58] [58] WANG L, LIU X D, LI J S, et al. Effect of rare-earth (RE) ionic radius on the dielectric properties of Sr99%RE1%TiO3 (RE=La, Nd, Yb) single crystals［J］. CrystEngComm, 2023, 25(1): 95-107.

[59] [59] GRUBER J B, SARDAR D K, NASH K L, et al. Comparative study of the crystal-field splitting of trivalent neodymium energy levels in polycrystalline ceramic and nanocrystalline yttrium oxide［J］. Journal of Applied Physics, 2007, 102(2): 023103.

[60] [60] GRUBER J B, SARDAR D K, NASH K L, et al. Spectral analysis of synthesized nanocrystalline aggregates of Er3+∶Y2O3［J］. Journal of Applied Physics, 2007, 101(11): 113116.

[63] [63] HERRICK C C, BEHRENS R G. Growth of large uraninite and thorianite single crystal from the melt using a cold-crucible technique［J］. Journal of Crystal Growth, 1981, 51(2): 183-189.

[64] [64] XU J Y, LEI X Y, JIANG X, et al. Industrial growth of yttria-stabilized cubic zirconia crystals by skull melting process［J］. Journal of Rare Earths, 2009, 27(6): 971-974.

[65] [65] BORIK M A, BREDIKHIN S I, KULEBYAKIN A V, et al. Melt growth, structure and properties of (ZrO2)1-x(Sc2O3)x solid solution crystals (x=0.035 0.11)［J］. Journal of Crystal Growth, 2016, 443: 54-61.

[66] [66] OSIKO V V, BORIK M A, LOMONOVA E E. Synthesis of refractory materials by skull melting technique［M］//DHANARAJ G, BYRAPPA K, PRASAD V, et al. Springer Handbook of Crystal Growth. Berlin, Heidelberg: Springer, 2010: 433-477.

[67] [67] ZHANG N, YIN Y Q, ZHANG J A, et al. Optimized growth of high length-to-diameter ratio Lu2O3 single crystal fibers by the LHPG method［J］. CrystEngComm, 2021, 23(7): 1657-1662.

[69] [69] ZHANG N, ZHOU H L, YIN Y R, et al. Exploring promising up-conversion luminescence single crystal fiber in sesquioxide family for high temperature optical thermometry application［J］. Journal of Alloys and Compounds, 2021, 889: 161348.

[70] [70] BERARD M F, WIRKUS C D, WILDER D R. Diffusion of oxygen in selected monocrystalline rare earth oxides[J]. Journal of the American Ceramic Society, 1968, 51(11): 643-647.

[71] [71] PETERS V. Spektroskopie und lasereigenschaften erbium-und praseodymdotierter hochschmelzender oxide［D］. Hamburg: University of Hamburg, 1998.

[72] [72] MLLER V. Characterisierung und optimierung von hochdotierten Yb∶YAG laserkristallen［D］. Hamburg: University of Hamburg, 2001.

[75] [75] BOLZ A. Energietransfer in ytterbium-dotierten sesquoxiden［D］. Hamburg: University of Hamburg, 2001.

[76] [76] KOELLING S. Untersuchungsbericht ILP 6-2000［D］. Hamburg: Technical University Hamburg, 2000.

[77] [77] HOSKINS R H, SOFFER B H. Stimulated emission from Y2O3∶Nd3+［J］. Applied Physics Letters, 1964, 4(1): 22-23.

[78] [78] IKESUE A, AUNG Y L. Synthesis and performance of advanced ceramic lasers[C]. Proceedings of the 2007 Conference on Lasers and Electro-Optics (CLEO), F 6-11 May 2007.

[79] [79] KRNKEL C. Rare-earth-doped sesquioxides for diode-pumped high-power lasers in the 1-, 2-, and 3-μm spectral range［J］. IEEE Journal of Selected Topics in Quantum Electronics, 2015, 21(1): 250-262.

[80] [80] FAN T Y. Optimizing the efficiency and stored energy in quasi-three-level lasers［J］. IEEE Journal of Quantum Electronics, 1992, 28(12): 2692-2697.

[81] [81] PETERS V, PETERMANN K, BOLZ A, et al. Ytterbium-doped sesquioxides as host materials for high-power laser applications［C］. Proceedings of the Laser 2001 - World of Photonics 15th International Conference on Lasers and Electrooptics in Europe, Munich, F 2001/06/18, 2001. Optica Publishing Group.

[82] [82] PETERS R. Ytterbium-dotierte sesquioxide als hocheffiziente lasermaterialien［D］. Hamburg: University of Hamburg, 2009.

[83] [83] PETERS R, KRNKEL C, FREDRICH-THORNTON S T, et al. Thermal analysis and efficient high power continuous-wave and mode-locked thin disk laser operation of Yb-doped sesquioxides［J］. Applied Physics B, 2011, 102(3): 509-514.

[84] [84] WEICHELT B, WENTSCH K S, VOSS A, et al. A 670 W Yb∶Lu2O3 thin-disk laser［J］. Laser Physics Letters, 2012, 9(2): 110-115.

[85] [85] TOKURAKAWA M, SHIRAKAWA A, UEDA K I, et al. Continuous wave and mode-locked Yb3+∶Y2O3 ceramic thin disk laser［J］. Optics Express, 2012, 20(10): 10847.

[86] [86] DAVID S P, JAMBUNATHAN V, YUE F X, et al. Efficient diode pumped Yb∶Y2O3 cryogenic laser［J］. Applied Physics B, 2019, 125(7): 1-5.

[87] [87] LIU Z Y, TOCI G, PIRRI A, et al. Fabrication and laser operation of Yb∶Lu2O3 transparent ceramics from co-precipitated nano-powders［J］. Journal of the American Ceramic Society, 2019, 102(12): 7491-7499.

[88] [88] ESSER S, RHRER C, XU X D, et al. Ceramic Yb∶Lu2O3 thin-disk laser oscillator delivering an average power exceeding 1 kW in continuous-wave operation［J］. Optics Letters, 2021, 46(24): 6063.

[89] [89] FU Y, GUO R Q, YU H H, et al. Efficient passively Q switched lasers with a large-energy stored Yb∶LuScO3 crystal［J］. Optics Letters, 2023, 48(2): 295-298.

[90] [90] KITAJIMA S, SHIRAKAWA A, YAGI H, et al. Sub-100 fs pulse generation from a Kerr-lens mode-locked Yb∶Lu2O3 ceramic thin-disk laser［J］. Optics Letters, 2018, 43(21): 5451-5454.

[91] [91] GREBORIO A, GUANDALINI A, AUS DER AU J. Sub-100 fs pulses with 12.5-W from Yb∶CALGO based oscillators［C］//SPIE Proceedings, Solid State Lasers XXI: Technology and Devices. San Francisco, California, USA. SPIE, 2012.

[92] [92] MODSCHING N, DRS J, FISCHER J, et al. Sub-100-fs Kerr lens mode-locked Yb∶Lu2O3 thin-disk laser oscillator operating at 21 W average power［J］. Optics Express, 2019, 27(11): 16111.

[93] [93] LIU X Q, JING W, HAO Q Q, et al. Characterisation of passively Q-switched Yb∶Lu2O3 ceramic laser based on graphdiyne absorber［J］. Infrared Physics & Technology, 2021, 115: 103739.

[94] [94] VAN DALFSEN K, ARAVAZHI S, GRIVAS C, et al. Thulium-doped channel waveguide laser with 1.6 W of output power and exceeding 80% slope efficiency［C］//2013 Conference on Lasers & Electro-Optics Europe & International Quantum Electronics Conference CLEO EUROPE/IQEC. May 12-16, 2013, Munich, Germany. IEEE, 2014: 1.

[95] [95] KOOPMANN P. Thulium- and holmium-doped sesquioxides for 2 μm lasers［D］. Hamburg: University of Hamburg, 2012.

[96] [96] KOOPMANN P, LAMRINI S, SCHOLLE K, et al. Efficient diode-pumped laser operation of Tm∶Lu2O3 around 2 μm［J］. Optics Letters, 2011, 36(6): 948-950.

[97] [97] ANTIPOV O, NOVIKOV A, LARIN S, et al. Highly efficient 2 μm CW and Q-switched Tm3+∶Lu2O3 ceramics lasers in-band pumped by a Raman-shifted erbium fiber laser at 1 670 nm［J］. Optics Letters, 2016, 41(10): 2298-2301.

[98] [98] ANTIPOV O L, GETMANOVSKIY Y A, BALABANOV S S, et al. 1940 nm, 1966 nm and 2066 nm multi-wavelength CW and passively-Q-switched operation of L-shaped Tm3+∶Lu2O3 ceramic laser in-band fiber-laser pumped at 1670 nm［J］. Laser Physics Letters, 2021, 18(5): 055001.

[99] [99] LI X X, DING M M, WANG J, et al. High power single frequency Tm∶Y2O3 ceramic laser at 2015 nm［J］. IEEE Photonics Journal, 2021, 13(3): 1-7.

[100] [100] LIU Z Y, TOCI G, PIRRI A, et al. Fabrication and characterizations of Tm∶Lu2O3 transparent ceramics for 2 μm laser applications［J］. Optical Materials, 2022, 131: 112705.

[101] [101] SUZUKI A, TOKURAKAWA M, KRANKEL C. High quality-factor Kerr-lens mode-locked Tm∶Sc2O3 laser beyond the gain bandwidth limitation［C］//2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC). June 23-27, 2019, Munich, Germany. IEEE, 2019: 1.

[102] [102] TOKURAKAWA M, FUJITA E, KRNKEL C. Sub-120 fs kerr-lens mode-locked Tm∶Sc2O3 laser In-band pumped by an Er;Yb fiber MOPA［C］//Conference on Lasers and Electro-Optics. San Jose, California. Washington, D.C.: OSA, 2018.

[103] [103] SUZUKI A, KRNKEL C, TOKURAKAWA M. Combined gain media 60 fs Kerr-lens mode-locked laser based on Tm∶Lu2O3 and Tm∶Sc2O3［C］//Conference on Lasers and Electro-Optics. San Jose, California. Washington, D.C.: Optica Publishing Group, 2021.

[104] [104] ZHANG N, LIU S, WANG Z, et al. Tm∶Y2O3 ceramic laser mode-locked with SESAM[C]. Proceedings of the Optica Advanced Photonics Congress. Barcelona: Optica Publishing Group, 2022/12/1.

[105] [105] YU X X, CHU H W, ZHA F Y, et al. Watt-level diode-pumped Tm∶YVO4 laser at 2.3 μm［J］. Optics Letters, 2022, 47(21): 5501-5504.

[106] [106] ZHA F Y, YU X X, CHU H W, et al. Compact diode-pumped continuous wave and passively Q switched Tm∶YAG laser at 2.33 μm［J］. Optics Letters, 2022, 47(23): 6265-6268.

[107] [107] JAMBUNATHAN V, MATEOS X, PUJOL M C, et al. Optimization of dopant concentration in Ho∶KLu(WO4)2 laser achieving 70% slope efficiency［J］. Laser Physics, 2013, 23(12): 125801.

[108] [108] BUDNI P A, POMERANZ L A, LEMONS M L, et al. Efficient mid-infrared laser using 1.9-μm-pumped Ho∶YAG and ZnGeP2 optical parametric oscillators［J］. Josa B, 2000, 17(5): 723-728.

[109] [109] FAN T Y, HUBER G, BYER R L, et al. Continuous-wave operation at 2.1 μm of a diode-laser-pumped, Tm-sensitized Ho:Y3Al5O12 laser at 300 K［J］. Optics Letters, 1987, 12(9): 678-680.

[110] [110] DONG J S, WANG W D, XUE Y Y, et al. Crystal growth and spectroscopic analysis of Ho∶Lu2O3 crystal for mid-infrared emission［J］. Journal of Luminescence, 2022, 251: 119192.

[111] [111] GHEORGHE C, LUPEI A, LUPEI V, et al. Spectroscopic properties of Ho3+ doped Sc2O3 transparent ceramic for laser materials［J］. Journal of Applied Physics, 2009, 105(12): 123110.

[112] [112] KOOPMANN P, LAMRINI S, SCHOLLE K, et al. Multi-watt laser operation and laser parameters of Ho-doped Lu2O3 at 212 μm［J］. Optical Materials Express, 2011, 1(8): 1447.

[113] [113] KOOPMANN P, LAMRINI S, SCHOLLE K, et al. Holmium-doped Lu2O3, Y2O3, and Sc2O3 for lasers above 21 μm［J］. Optics Express, 2013, 21(3): 3926.

[114] [114] WANG F, TANG J W, LI E H, et al. Ho3+∶Y2O3 ceramic laser generated over 113 W of output power at 2117 nm［J］. Optics Letters, 2019, 44(24): 5933-5936.

[115] [115] LOIKO P, BASYROVA L, MAKSIMOV R, et al. Comparative study of Ho∶Y2O3 and Ho∶Y3Al5O12 transparent ceramics produced from laser-ablated nanoparticles［J］. Journal of Luminescence, 2021, 240: 118460.

[116] [116] HUANG D D, YANG Q H, WANG Y G, et al. Spectral and laser properties of Yb and Ho co-doped (YLa)2O3 transparent ceramic［J］. Chinese Physics B, 2013, 22(3): 037801.

[117] [117] LI T, BEIL K, KRNKEL C, et al. Laser performance of highly doped Er∶Lu2O3 at 2.8 μm［C］//Lasers, Sources, and Related Photonic Devices. San Diego, California. Washington, D.C.: OSA, 2012.

[119] [119] POLLNAN M, JACKSON S D. Erbium 3 μm fiber lasers［J］. IEEE Journal of Selected Topics in Quantum Electronics, 2001, 7(1): 30-40.

[120] [120] LI T, BEIL K, KRNKEL C, et al. Efficient high-power continuous wave Er∶Lu2O3 laser at 285 μm［J］. Optics Letters, 2012, 37(13): 2568.

[121] [121] UEHARA H, TOKITA S, KAWANAKA J, et al. Optimization of laser emission at 28 μm by Er∶Lu2O3 ceramics［J］. Optics Express, 2018, 26(3): 3497.

[122] [122] YAO W C, UEHARA H, TOKITA S, et al. LD-pumped 2.8 μm Er∶Lu2O3 ceramic laser with 6.7 W output power and >30% slope efficiency［J］. Applied Physics Express, 2021, 14(1): 012001.

[123] [123] ZONG M Y, HOU W T, ZHAO Y H, et al. 2.7 μm laser properties research of Er∶Y2O3 crystal［J］. Infrared Physics & Technology, 2022, 127: 104460.

[124] [124] DING M M, LI X X, WANG F, et al. Power scaling of diode-pumped Er∶Y2O3 ceramic laser at 2.7 μm［J］. Applied Physics Express, 2022, 15(6): 062004.

[125] [125] DING M M, WANG J, WANG F, et al. High-power Er∶Y2O3 ceramic laser with an optical vortex beam output at 2.7 μm［J］. Frontiers in Physics, 2023, 11: 1119263.

[126] [126] DING M M, LI X X, WANG F, et al. Single longitudinal mode and widely tunable Er∶Y2O3 ceramic laser at 2.7 μm［J］. IEEE Photonics Journal, 2022, 15(1): 1-4.

[127] [127] WANG L, HUANG H T, SHEN D Y, et al. High power and short pulse width operation of passively Q-switched Er∶Lu2O3 ceramic laser at 2.7 μm［J］. Applied Sciences, 2018, 8(5): 801.

[128] [128] UEHARA H, TOKITA S, KAWANAKA J, et al. A passively Q-switched compact Er∶Lu2O3 ceramics laser at 2.8 μm with a graphene saturable absorber［J］. Applied Physics Express, 2019, 12(2): 022002.

[129] [129] VEJKAR R, ULC J, JELNKOV H. Er∶Y2O3 high-repetition rate picosecond 2.7 μm laser［J］. Laser Physics Letters, 2019, 16(7): 075802.

[130] [130] SU C Y, LIU Y Z, FENG T L, et al. Optical modulation of the MXene Ti3C2Tx saturable absorber for Er∶Lu2O3 laser［J］. Optical Materials, 2021, 115: 110949.