[1] D.-S. Tsai, K.-K. Liu, D.-H. Lien, M.-L. Tsai, C.-F. Kang, C.-A. Lin, L.-J. Li, J.-H. He. Few-layer MoS₂ with high broadband photogain and fast optical switching for use in harsh environments. ACS Nano, 2013, 7: 3905-3911.

[2] K. Wang, J. Wang, J. Fan, M. Lotya, A. O’Neill, D. Fox, Y. Feng, X. Zhang, B. Jiang, Q. Zhao, H. Zhang, J. N. Coleman, L. Zhang, W. J. Blau. Ultrafast saturable absorption of two-dimensional MoS₂ nanosheets. ACS Nano, 2013, 7: 9260-9267.

[3] K. Wang, Y. Feng, C. Chang, J. Zhan, C. Wang, Q. Zhao, J. N. Coleman, L. Zhang, W. J. Blau, J. Wang. Broadband ultrafast nonlinear absorption and nonlinear refraction of layered molybdenum dichalcogenide semiconductors. Nanoscale, 2014, 6: 10530-10535.

[4] S. H. Kassani, R. Khazaeinezhad, H. Jeong, T. Nazari, D.-I. Yeom, K. Oh. All-fiber Er-doped Q-switched laser based on tungsten disulfide saturable absorber. Opt. Mater. Express, 2015, 5: 373-379.

[5] S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, J. Wang. Broadband few-layer MoS₂ saturable absorber. Adv. Mater., 2014, 26: 3538-3544.

[6] H. Zhang, S. B. Lu, J. Zheng, J. Du, S. C. Wen, D. Y. Tang, K. P. Loh. Molybdenum disulfide (MoS₂) as a broadband saturable absorber for ultra-fast photonics. Opt. Express, 2014, 22: 7249-7260.

[7] X. Fu, J. Qian, X. Qiao, P. Tan, Z. Peng. Nonlinear saturable absorption of vertically stood WS₂ nanoplates. Opt. Lett., 2014, 39: 6450-6453.

[8] D. Mao, Y. Wang, C. Ma, L. Han, B. Jiang, X. Gan, S. Hua, W. Zhang, T. Mei, J. Zhao. WS₂ mode-locked ultrafast fiber laser. Sci. Rep., 2015, 5: 7965.

[9] K. P. Loh, H. Zhang, W. Z. Chen, W. Ji. Templated deposition of MoS₂ nanotubules using single source precursor and studies of their optical limiting properties. J. Phys. Chem. B, 2006, 110: 1235-1239.

[10] E. Hendry, P. J. Hale, J. Moger, A. K. Savchenko, S. A. Mikhailov. Coherent nonlinear optical response of graphene. Phy. Rev. Lett., 2010, 105: 097401.

[11] G. Wang, S. Zhang, X. Zhang, L. Zhang, Y. Cheng, D. Fox, H. Zhang, J. N. Coleman, W. J. Blau, J. Wang. Tunable nonlinear refractive index of two-dimensional MoS₂, WS₂, and MoSe₂ nanosheet dispersions [Invited]. Photon. Res., 2015, 3: A51-A55.

[12] S. J. Varma, J. Kumar, Y. Li, K. Layne, J. Wu, C. Liang, Y. Nakanishi, A. Aliyan, W. Yang, P. M. Ajayan, J. Thomas. 2D TiS₂ layers: a superior nonlinear optical limiting material. Adv. Opt. Mater., 2017, 5: 1700713.

[13] S. Y. Set, H. Yaguchi, Y. Tanaka, M. Jablonski. Laser mode locking using a saturable absorber incorporating carbon nanotubes. J. Lightwave Technol., 2004, 22: 51-56.

[14] Y.-W. Song, S. Yamashita, C. S. Goh, S. Y. Set. Carbon nanotube mode lockers with enhanced nonlinearity via evanescent field interaction in D-shaped fibers. Opt. Lett., 2007, 32: 148-150.

[15] Q. Bao, H. Zhang, Y. Wang, Z. Ni, Y. Yang, Z. X. Shen, K. P. Loh, D. Y. Tang. Atomic-layer graphene as a saturable absorber for ultrafast pulsed lasers. Adv. Funct. Mater., 2009, 19: 3077-3083.

[16] Z. Sun, T. Hasan, F. Torrisi, D. Popa, G. Privitera, F. Wang, F. Bonaccorso, D. M. Basko, A. C. Ferrari. Graphene mode-locked ultrafast laser. ACS Nano, 2010, 4: 803-810.

[17] Y.-W. Song, S.-Y. Jang, W.-S. Han, M.-K. Bae. Graphene mode-lockers for fiber lasers functioned with evanescent field interaction. Appl. Phys. Lett., 2010, 96: 051122.

[18] K. P. Loh, Q. Bao, G. Eda, M. Chhowalla. Graphene oxide as a chemically tunable platform for optical applications. Nat. Chem., 2010, 2: 1015-1024.

[19] S. Ko, J. Lee, J. Koo, B. S. Joo, M. Gu, J. H. Lee. Chemical wet etching of an optical fiber using a hydrogen fluoride-free solution for a saturable absorber based on the evanescent field interaction. J. Lightwave Technol., 2016, 34: 3776-3784.

[20] BernardF.ZhangH.GorzaS. P.EmplitP., “Towards mode-locked fiber laser using topological insulators,” in Nonlinear Photonics, OSA Technical Digest (online) (Optical Society of America, 2012), paper NTh1A.5.

[21] Y. Chen, C. Zhao, H. Huang, S. Chen, P. Tang, Z. Wang, S. Lu, H. Zhang, S. Wen, D. Tang. Self-assembled topological insulator: Bi₂Se₃ membrane as a passive Q-switcher in an erbium-doped fiber laser. J. Lightwave Technol., 2013, 31: 2857-2863.

[22] J. Lee, J. Koo, Y. M. Jhon, J. H. Lee. A femtosecond pulse erbium fiber laser incorporating a saturable absorber based on bulk-structured Bi₂Te₃ topological insulator. Opt. Express, 2014, 22: 6165-6173.

[23] H. Liu, X.-W. Zheng, M. Liu, N. Zhao, A.-P. Luo, Z.-C. Luo, W.-C. Xu, H. Zhang, C.-J. Zhao, S.-C. Wen. Femtosecond pulse generation from a topological insulator mode-locked fiber laser. Opt. Express, 2014, 22: 6868-6873.

[24] J. Sotor, G. Sobon, W. Macherzynski, P. Paletko, K. Grodecki, K. M. Abramski. Mode-locking in Er-doped fiber laser based on mechanically exfoliated Sb₂Te₃ saturable absorber. Opt. Mater. Express, 2014, 4: 1-6.

[25] Y. I. Jhon, J. Lee, Y. M. Jhon, J. H. Lee. Topological insulators for mode-locking of 2-μm fiber lasers. IEEE J. Sel. Top. Quantum Electron., 2018, 24: 1102208.

[26] K. Wu, X. Zhang, J. Wang, J. Chen. 463-MHz fundamental mode-locked fiber laser based on few-layer MoS₂ saturable absorber. Opt. Lett., 2015, 40: 1374-1377.

[27] R. I. Woodward, E. J. R. Kelleher, R. C. T. Howe, G. Hu, F. Torrisi, T. Hasan, S. V. Popov, J. R. Taylor. Tunable Q-switched fiber laser based on saturable edge-state absorption in few-layer molybdenum disulfide (MoS₂). Opt. Express, 2014, 22: 31113-31122.

[28] J. Koo, J. Park, J. Lee, Y. M. Jhon, J. H. Lee. Femtosecond harmonic mode-locking of a fiber laser at 3.27 GHz using a bulk-like, MoSe₂-based saturable absorber. Opt. Express, 2016, 24: 10575-10589.

[29] J. Lee, J. Koo, J. Lee, Y. M. Jhon, J. H. Lee. All-fiberized, femtosecond laser at 1912 nm using a bulk-like MoSe₂ saturable absorber. Opt. Mater. Express, 2017, 7: 2968-2979.

[30] D. Mao, X. She, B. Du, D. Yang, W. Zhang, K. Song, X. Cui, B. Jiang, T. Peng, J. Zhao. Erbium-doped fiber laser passively mode locked with few-layer WSe₂/MoSe₂ nanosheets. Sci. Rep., 2016, 6: 23583.

[31] D. Mao, B. Du, D. Yang, S. Zhang, Y. Wang, W. Zhang, X. She, H. Cheng, H. Zeng, J. Zhao. Nonlinear saturable absorption of liquid-exfoliated molybdenum/tungsten ditelluride nanosheets. Small, 2016, 12: 1489-1497.

[32] J. Koo, Y. I. Jhon, J. Park, J. Lee, Y. M. Jhon, J. H. Lee. Near-infrared saturable absorption of defective bulk-structured WTe₂ for femtosecond laser mode-locking. Adv. Funct. Mater., 2016, 26: 7454-7461.

[33] K. Niu, R. Sun, Q. Chen, B. Man, H. Zhang. Passively mode-locked Er-doped fiber laser based on SnS₂ nanosheets as a saturable absorber. Photon. Res., 2018, 6: 72-76.

[34] Y. Cui, F. Lu, X. Liu. Nonlinear saturable and polarization induced absorption of rhenium disulfide. Sci. Rep., 2017, 7: 40080.

[35] F. Lu. Passively harmonic mode-locked fiber laser based on ReS₂ saturable absorber. Mod. Phys. Lett. B, 2017, 31: 1750206.

[36] X. Su, H. Nie, Y. Wang, G. Li, B. Yan, B. Zhang, K. Yang, J. He. Few-layered ReS₂ as saturable absorber for 2.8  μm solid state laser. Opt. Lett., 2017, 42: 3502-3505.

[37] D. Mao, X. Cui, X. Gan, M. Li, W. Zhang, H. Lu, J. Zhao. Passively Q-switched and mode-locked fiber laser based on an ReS₂ saturable absorber. IEEE J. Sel. Top. Quantum Electron., 2018, 24: 1100406.

[38] X. Xu, M. Jiang, D. Li, R. Wang, Z. Ren, J. Bai. Passive Q-switching based on ReS₂ saturable absorber in Er-doped fiber laser at 1532  nm. Opt. Quantum Electron., 2018, 50: 39.

[39] L. Du, G. Jiang, L. Miao, B. Huang, J. Yi, C. Zhao, S. Wen. Few-layer rhenium diselenide: an ambient-stable nonlinear optical modulator. Opt. Mater. Express, 2018, 8: 926-935.

[40] Z. Li, N. Dong, Y. Zhang, J. Wang, H. Yu, F. Chen. Invited article: mode-locked waveguide lasers modulated by rhenium diselenide as a new saturable absorber. APL Photon., 2018, 3: 080802.

[41] C. Li, Y. Leng, J. Huo. Diode-pumped solid-state Q-switched laser with rhenium diselenide as saturable absorber. Appl. Sci., 2018, 8: 1753.

[42] C. Li, Y. Leng, J. Huo. ReSe₂ as a saturable absorber in a Tm-doped yttrium lithium fluoride (Tm:YLF) pulse laser. Chin. Opt. Lett., 2019, 17: 011402.

[43] J. Wang, Z. Jiang, H. Chen, J. Li, J. Yin, J. Wang, T. He, P. Yan, S. Ruan. High energy soliton pulse generation by a magnetron-sputtering-deposition-grown MoTe₂ saturable absorber. Photon. Res., 2018, 6: 535-541.

[44] J. Wang, H. Chen, Z. Jiang, J. Yin, J. Wang, M. Zhang, T. He, J. Li, P. Yan, S. Ruan. Mode-locked thulium-doped fiber laser with chemical vapor deposited molybdenum ditelluride. Opt. Lett., 2018, 43: 1998-2001.

[45] J. Wang, Z. Jiang, H. Chen, J. Li, J. Yin, J. Wang, T. He, P. Yan, S. Ruan. Magnetron-sputtering deposited WTe₂ for an ultrafast thulium-doped fiber laser. Opt. Lett., 2017, 42: 5010-5013.

[46] Y. Chen, G. Jiang, S. Chen, Z. Guo, X. Yu, C. Zhao, H. Zhang, Q. Bao, S. Wen, D. Tang, D. Fan. Mechanically exfoliated black phosphorus as a new saturable absorber for both Q-switching and mode-locking laser operation. Opt. Express, 2015, 23: 12823-12833.

[47] K. Park, J. Lee, Y. T. Lee, W.-K. Choi, J. H. Lee, Y.-W. Song. Black phosphorus saturable absorber for ultrafast mode-locked pulse laser via evanescent field interaction. Ann. Phys., 2015, 527: 770-776.

[48] S. B. Lu, L. L. Miao, Z. N. Guo, X. Qi, C. J. Zhao, H. Zhang, S. C. Wen, D. Y. Tang, D. Y. Fan. Broadband nonlinear optical response in multi-layer black phosphorus: an emerging infrared and mid-infrared optical material. Opt. Express, 2015, 23: 11183-11194.

[49] X.-D. Wang, Z.-C. Luo, H. Liu, M. Liu, A.-P. Luo, W.-C. Xu. Microfiber-based gold nanorods as saturable absorber for femtosecond pulse generation in a fiber laser. Appl. Phys. Lett., 2014, 105: 161107.

[50] D. Fan, C. Mou, X. Bai, S. Wang, N. Chen, X. Zeng. Passively Q-switched erbium-doped fiber laser using evanescent field interaction with gold-nanosphere based saturable absorber. Opt. Express, 2014, 22: 18537-18542.

[51] J. Lee, B.-K. Yu, Y. I. Jhon, J. Koo, S. J. Kim, Y. M. Jhon, J. H. Lee. Filled skutterudites for broadband saturable absorbers. Adv. Opt. Mater., 2017, 5: 1700096.

[52] J. Lee, Y. Kim, K. Lee, J. H. Lee. Femtosecond mode-locking of a fiber laser using a CoSb₃-skutterudite-based saturable absorber [Invited]. Photon. Res., 2018, 6: C36-C43.

[53] Y. I. Jhon, J. Koo, B. Anasori, M. Seo, J. H. Lee, Y. Gogotsi, Y. M. Jhon. Metallic MXene saturable absorber for femtosecond mode-locked lasers. Adv. Mater., 2017, 29: 1702496.

[54] X. Jiang, S. Liu, W. Liang, S. Luo, Z. He, Y. Ge, H. Wang, R. Cao, F. Zhang, Q. Wen, J. Li, Q. Bao, D. Fan, H. Zhang. Broadband nonlinear photonics in few-layer MXene Ti₃C₂T_x (T=F, O, or OH). Laser Photon. Rev., 2018, 12: 1700229.

[55] Y. I. Jhon, J. Lee, M. Seo, J. H. Lee, Y. M. Jhon. van der Waals layered tin selenide as highly nonlinear ultrafast saturable absorber. Adv. Opt. Mater., 2019, 7: 1801745.

[56] Q. H. Wang, K. Kalantar-Zadeh, A. Kis, J. N. Coleman, M. S. Strano. Electronics and optoelectronics of two-dimensional transition metal dichalcogenides. Nat. Nanotechnol., 2012, 7: 699-712.

[57] S. Zhang, N. Dong, N. McEvoy, M. O’Brien, S. Winters, N. C. Berner, C. Yim, Y. Li, X. Zhang, Z. Chen, L. Zhang, G. S. Duesberg, J. Wang. Direct observation of degenerate two-photon absorption and its saturation in WS₂ and MoS₂ monolayer and few-layer films. ACS Nano, 2015, 9: 7142-7150.

[58] R. I. Woodward, R. T. Murray, C. F. Phelan, R. E. P. de Oliveira, T. H. Runcorn, E. J. R. Kelleher, S. Li, E. C. de Oliveira, G. J. M. Fechine, G. Eda, C. J. S. de Matos. Characterization of the second- and third-order nonlinear optical susceptibilities of monolayer MoS₂ using multiphoton microscopy. 2D Mater., 2017, 4: 011006.

[59] N. Kumar, S. Najmaei, Q. Cui, F. Ceballos, P. M. Ajayan, J. Lou, H. Zhao. Second harmonic microscopy of monolayer MoS₂. Phys. Rev. B, 2013, 87: 161403.

[60] R. Wang, H.-C. Chien, J. Kumar, N. Kumar, H.-Y. Chiu, H. Zhao. Third-harmonic generation in ultrathin films of MoS₂. ACS Appl. Mater. Interfaces, 2014, 6: 314-318.

[61] S. Yang, C. Wang, H. Sahin, H. Chen, Y. Li, S.-S. Li, A. Suslu, F. M. Peeters, Q. Liu, J. Li, S. Tongay. Tuning the optical, magnetic, and electrical properties of ReSe₂ by nanoscale strain engineering. Nano Lett., 2015, 15: 1660-1666.

[62] H. Zhao, J. Wu, H. Zhong, Q. Guo, X. Wang, F. Xia, L. Yang, P. Tan, H. Wang. Interlayer interactions in anisotropic atomically thin rhenium diselenide. Nano Res., 2015, 8: 3651-3661.

[63] H. Yang, H. Jussila, A. Autere, H.-P. Komsa, G. Ye, X. Chen, T. Hasan, Z. Sun. Optical waveplates based on birefringence of anisotropic two-dimensional layered materials. ACS Photon., 2017, 4: 3023-3030.

[64] C. M. Corbet, S. S. Sonde, E. Tutuc, S. K. Banerjee. Improved contact resistance in ReSe₂ thin film field-effect transistors. Appl. Phys. Lett., 2016, 108: 162104.

[65] F. Qi, X. Wang, B. Zheng, Y. Chen, B. Yu, J. Zhou, J. He, P. Li, W. Zhang, Y. Li. Self-assembled chrysanthemum-like microspheres constructed by few-layer ReSe₂ nanosheets as a highly efficient and stable electrocatalyst for hydrogen evolution reaction. Electrochim. Acta, 2017, 224: 593-599.

[66] P. Hu, M. Jia, Y. Zuo, L. He. A silica/PVA adhesive hybrid material with high transparency, thermostability and mechanical strength. RSC Adv., 2017, 7: 2450-2459.

[67] X. Zhang, Y. Zhou, J. Zhang. In-situ reduced graphene oxide-polyvinyl alcohol composite coatings as protective layers on magnesium substrates. Prog. Nat. Sci., 2017, 27: 326-328.

[68] D. Wolverson, S. Crampin, A. S. Kazemi, A. Ilie, S. J. Bending. Raman spectra of monolayer, few-layer, and bulk ReSe₂: an anisotropic layered semiconductor. ACS Nano, 2014, 8: 11154-11164.

[69] S. Jiang, Z. Zhang, N. Zhang, Y. Huan, Y. Gong, M. Sun, J. Shi, C. Xie, P. Yang, Q. Fang, H. Li, L. Tong, D. Xie, L. Gu, P. Liu, Y. Zhang. Application of chemical vapor-deposited monolayer ReSe₂ in the electrocatalytic hydrogen evolution reaction. Nano Res., 2018, 11: 1787-1797.

[70] S. Yang, S. Tongay, Y. Li, Q. Yue, J.-B. Xia, S.-S. Li, J. Li, S.-H. Wei. Layer-dependent electrical and optoelectronic responses of ReSe₂ nanosheet transistors. Nanoscale, 2014, 6: 7226-7231.

[71] H.-X. Zhong, S. Gao, J.-J. Shi, L. Yang. Quasiparticle band gaps, excitonic effects, and anisotropic optical properties of the monolayer distorted 1T diamond-chain structures ReS₂ and ReSe₂. Phys. Rev. B, 2015, 92: 115438.

[72] R. I. Woodward, E. J. R. Kelleher. 2D saturable absorber for fibre lasers. Appl. Sci., 2015, 5: 1440-1456.

[73] M. Sheik-Bahae, A. A. Said, E. W. Van Stryland. High-sensitivity, single-beam n₂ measurements. Opt. Lett., 1989, 14: 955-957.

[74] Y. Ge, Z. Zhu, Y. Xu, Y. Chen, S. Chen, Z. Liang, Y. Song, Y. Zou, H. Zeng, S. Xu, H. Zhang, D. Fan. Broadband nonlinear photoresponse of 2D TiS₂ for ultrashort pulse generation and all-optical thresholding devices. Adv. Opt. Mater., 2018, 6: 1701166.

[75] X. Jiang, L. Zhang, S. Liu, Y. Zhang, Z. He, W. Li, F. Zhang, Y. Shi, W. Lü, Y. Li, Q. Wen, J. Li, J. Feng, S. Ruan, Y.-J. Zeng, X. Zhu, Y. Lu, H. Zhang. Ultrathin metal-organic framework: an emerging broadband nonlinear optical material for ultrafast photonics. Adv. Opt. Mater., 2018, 6: 1800561.

[76] M. Zhang, R. C. T. Howe, R. I. Woodward, E. J. R. Kelleher, F. Torrisi, G. Hu, S. V. Popov, J. R. Taylor, T. Hasan. Solution processed MoS₂-PVA composite for sub-bandgap mode-locking of a wideband tunable ultrafast Er:fiber laser. Nano Res., 2015, 8: 1522-1534.

[77] M. Zhang, G. Hu, G. Hu, R. C. T. Howe, L. Chen, Z. Zheng, T. Hasan. Yb- and Er-doped fiber laser Q-switched with an optically uniform, broadband WS₂ saturable absorber. Sci. Rep., 2015, 5: 17482.

[78] X. Zheng, Y. Zhang, R. Chen, X. Cheng, Z. Xu, T. Jiang. Z-scan measurement of the nonlinear refractive index of monolayer WS₂. Opt. Express, 2015, 23: 15616-15623.

[79] S. Bikorimana, P. Lama, A. Walser, R. Dorsinville, S. Anghel, A. Mitioglu, A. Micu, L. Kulyuk. Nonlinear optical responses in two-dimensional transition metal dichalcogenide multilayer: WS₂, WSe₂, MoS₂ and Mo_0.5W_0.5S₂. Opt. Express, 2016, 24: 20685-20695.

[80] C. Hönninger, R. Paschotta, F. Morier-Genoud, M. Moser, U. Keller. Q-switching stability limits of continuous-wave passive mode locking. J. Opt. Soc. Am. B, 1999, 16: 46-56.

[81] J. Jeon, J. Lee, J. H. Lee. Numerical study on the minimum modulation depth of a saturable absorber for stable fiber laser mode locking. J. Opt. Soc. Am. B, 2015, 32: 31-37.

[82] K. Wu, B. Chen, X. Zhang, S. Zhang, C. Guo, C. Li, P. Xiao, J. Wang, L. Zhou, W. Zou, J. Chen. High-performance mode-locked and Q-switched fiber lasers based on novel 2D materials of topological insulators, transition metal dichalcogenides and black phosphorus: review and perspective (invited). Opt. Commun., 2018, 406: 214-229.

[83] S. M. J. Kelly. Characteristic sideband instability of periodically amplified average soliton. Electron. Lett., 1992, 28: 806-807.