[1] O. Svelto, Principles of Lasers (Springer, 2010).

[2] A. E. Siegman, Lasers (University Science Books, 1990).

[3] F. Dausinger, F. Lichtner, and H. Lubatschowski, Femtosecond Technology for Technical and Medical Applications (Springer, 2004).

[4] W. M. Steen and J. Mazumder, Laser Material Processing (Springer, 2010).

[5] B. H. Chapman, E. J. R. Kelleher, K. M. Golant, S. V. Popov, and J. R. Taylor, “Amplification of picosecond pulses and gigahertz signals in bismuth-doped fiber amplifiers,” Opt. Lett. 36, 1446–1448 (2011).

[6] N. D. Psaila, R. R. Thomson, H. T. Bookey, A. K. Kar, N. Chiodo, R. Osellame, G. Cerullo, A. Jha, and S. Shen, “Er:Yb-doped oxyfluoride silicate glass waveguide amplifier fabricated using femtosecond laser inscription,” Appl. Phys. Lett. 90, 131102 (2007).

[7] U. Keller, K. J. Weingarten, F. X. Kartner, D. Kopf, B. Braun, I. D. Jung, R. Fluck, C. Honninger, N. Matuschek, and J. Aus der Au, “Semiconductor saturable absorber mirrors (SESAMs) for femtosecond to nanosecond pulse generation in solid-state lasers,” IEEE J. Quant. Electron. 2, 435–453 (1996).

[8] U. Keller, “Recent developments in compact ultrafast lasers,” Nature 424, 831–838 (2003).

[9] K. Tamura, H. A. Haus, and E. P. Ippen, “Self-starting additive pulse mode-locked erbium fibre ring laser,” Electron. Lett. 28, 2226–2228 (1992).

[10] S. Iijima, “Helical microtubules of graphitic carbon,” Nature 354, 56–58 (1991).

[11] P. Avouris, M. Freitag, and V. Perebeinos, “Carbon-nanotube photonics and optoelectronics,” Nat. Photonics 2, 341–350 (2008).

[12] K. Novoselov, A. Geim, S. Morozov, D. Jiang, Y. Zhang, S. V. Dubonos, I. V. Grigorieva, and A. A. Firsov, “Electric field effect in atomically thin carbon films,” Science 306, 666–669 (2004).

[13] F. Bonaccorso, Z. Sun, T. Hasan, and A. C. Ferrari, “Graphene photonics and optoelectronics,” Nat. Photonics 4, 611–622 (2010).

[14] S. Set, H. Yaguchi, Y. Tanaka, and M. Jablonski, “Ultrafast fiber pulsed lasers incorporating carbon nanotubes,” IEEE J. Sel. Top. Quantum Electron. 10, 137–146 (2004).

[15] T. Hasan, Z. Sun, F. Wang, F. Bonaccorso, P. H. Tan, A. G. Rozhin, and A. C. Ferrari, “Nanotube-polymer composites for ultrafast photonics,” Adv. Mater. 21, 3874–3899 (2009).

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

[17] Q. Bao, H. Zhang, Y. Wang, Z. Ni, Y. Yan, Z. X. Shen, K. P. Loh, and D. Y. Tang, “Atomic-layer graphene as a saturable absorber for ultrafast pulsed lasers,” Adv. Funct. Mater. 19, 3077–3083 (2009).

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

[19] M. Z. Hasan and C. L. Kane, “Colloquium: Topological insulators,” Rev. Mod. Phys. 82, 3045–3067 (2010).

[20] J. A. Wilson and A. Yoffe, “The transition metal dichalcogenides discussion and interpretation of the observed optical, electrical and structural properties,” Adv. Phys. 18, 193–335 (1969).

[21] R. Ganatra and Q. Zhang, “Few-layer MoS2: a promising layered semiconductor,” ACS Nano 8, 4074–4099 (2014).

[22] R. G. Dickson and L. Pauling, “The crystal structure of molydenite,” J. Am. Chem. Soc. 45, 1466–1471 (1923).

[23] A. Splendiani, L. Sun, Y. Zhang, T. Li, J. Kim, C.-Y. Chim, G. Galli, and F. Wang, “Emerging photoluminescence in monolayer MoS2,” Nano Lett. 10, 1271–1275 (2010).

[24] B. Radisavljevic, A. Radenovic, J. Brivio, V. Giacometti, and A. Kis, “Single-layer MoS2 transistors,” Nat. Nanotechnol. 6, 147– 150 (2011).

[25] 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, and W. J. Blau, “Ultrafast saturable absorption of two-dimensional MoS2 nanosheets,” ACS Nano 7, 9260–9267 (2013).

[26] A. K. Geim and K. S. Novoselov, “The rise of graphene,” Nat. Mater. 6, 183–191 (2007).

[27] R. Frindt and A. Yoffe, “Physical properties of layer structures: optical properties and photoconductivity of thin crystals of molybdenum disulphide,” Proc. R. Soc. A 273, 69–83 (1963).

[28] R. F. Frindt, “Optical absorption of a few unit-cell layers of MoS2,” Phys. Rev. 140, A536–A539 (1965).

[29] R. F. Frindt, “Single crystals of MoS2 several molecular layers thick,” J. Appl. Phys. 37, 1928–1929 (1966).

[30] P. Joensen, R. F. Frindt, and S. R. Morrison, “Single-layer MoS2,” Mater. Res. Bull. 21, 457–461 (1986).

[31] F. Bonaccorso and Z. Sun, “Solution processing of graphene, topological insulators and other 2D crystals for ultrafast photonics,” Opt. Mater. Express 4, 63–78 (2014).

[32] F. Bonaccorso, A. Lombardo, T. Hasan, Z. Sun, L. Colombo, and A. C. Ferrari, “Production and processing of graphene and 2D crystals,” Mater. Today 15, 564–589 (2012).

[33] K. S. Novoselov, D. Jiang, F. Schedin, T. J. Booth, V. V. Khotkevich, S. V. Morozov, and A. K. Geim, “Two-dimensional atomic crystals,” Proc. Natl. Acad. Sci. U.S.A. 102, 10451–10453 (2005).

[34] K. F. Mak, C. Lee, J. Hone, J. Shan, and T. F. Heinz, “Atomically thin MoS2: a new direct-gap semiconductor,” Phys. Rev. Lett. 105, 136805 (2010).

[35] S. Helveg, J. V. Lauritsen, E. L?gsgaard, I. Stensgaard, J. K. N?rskov, B. S. Clausen, H. Tops?e, and F. Besenbacher, “Atomic-scale structure of single-layer MoS2 nanoclusters,” Phys. Rev. Lett. 84, 951–954 (2000).

[36] Y. Zhan, Z. Liu, S. Najmaei, P. M. Ajayan, and J. Lou, “Large-area vapor-phase growth and characterization of MoS2 atomic layers on a SiO2 substrate,” Small 8, 966–971 (2012).

[37] Y.-H. Lee, X.-Q. Zhang, W. Zhang, M.-T. Chang, C.-T. Lin, K.-D. Chang, Y.-C. Yu, J. T.-W. Wang, C.-S. Chang, L.-J. Li, and T.-W. Lin, “Synthesis of large-area MoS2 atomic layers with chemical vapor deposition,” Adv. Mater. 24, 2320–2325 (2012).

[38] K.-K. Liu, W. Zhang, Y.-H. Lee, Y.-C. Lin, M.-T. Chang, C.-Y. Su, C.-S. Chang, H. Li, Y. Shi, H. Zhang, C.-S. Lai, and L.-J. Li, “Growth of large-area and highly crystalline MoS2 thin layers on insulating substrates,” Nano Lett. 12, 1538–1544 (2012).

[39] Y.-H. Lee, L. Yu, H. Wang, W. Fang, X. Ling, Y. Shi, C.-T. Lin, J.-K. Huang, M.-T. Chang, C.-S. Chang, M. Dresselhaus, T. Palacios, L.-J. Li, and J. Kong, “Synthesis and transfer of single-layer transition metal disulfides on diverse surfaces,” Nano Lett. 13, 1852–1857 (2013).

[40] S. Najmaei, Z. Liu, W. Zhou, X. Zou, G. Shi, S. Lei, B. I. Yakobson, J.-C. Idrobo, P. M. Ajayan, and J. Lou, “Vapour phase growth and grain boundary structure of molybdenum disulphide atomic layers,” Nat. Mater. 12, 754–759 (2013).

[41] Y. Zhan, L. Wang, J. Y. Wang, H. W. Li, and Z. H. Yu, “Yb : YAG thin disk laser passively Q-switched by a hydro-thermal grown molybdenum disulfide saturable absorber,” Laser Phys. 25, 025901 (2015).

[42] S. Wang, H. Yu, H. Zhang, A. Wang, M. Zhao, Y. Chen, L. Mei, and J. Wang, “Broadband few-layer MoS2 saturable absorbers,” Adv. Mater. 26, 3538–3544 (2014).

[43] V. Fominski, V. Nevolin, R. Romanov, and I. Smurov, “Ionassisted deposition of MoSx films from laser-generated plume under pulsed electric field,” J. Appl. Phys. 89, 1449 (2001).

[44] G. Eda, H. Yamaguchi, D. Voiry, T. Fujita, M. Chen, and M. Chhowalla, “Photoluminescence from chemically exfoliated MoS2,” Nano Lett. 11, 5111–5116 (2011).

[45] J. Zheng, H. Zhang, S. Dong, Y. Liu, C. T. Nai, H. S. Shin, H. Y. Jeong, B. Liu, and K. P. Loh, “High yield exfoliation of twodimensional chalcogenides using sodium naphthalenide,” Nat. Commun. 5, 2995 (2014).

[46] J. N. Coleman, M. Lotya, A. O’Neill, S. D. Bergin, P. J. King, U. Khan, K. Young, A. Gaucher, S. De, R. J. Smith, I. V. Shvets, S. K. Arora, G. Stanton, H.-Y. Kim, K. Lee, G. T. Kim, G. S. Duesberg, T. Hallam, J. J. Boland, J. J. Wang, J. F. Donegan, J. C. Grunlan, G. Moriarty, A. Shmeliov, R. J. Nicholls, J. M. Perkins, E. M. Grieveson, K. Theuwissen, D. W. McComb, P. D. Nellist, and V. Nicolosi, “Two-dimensional nanosheets produced by liquid exfoliation of layered materials,” Science 331, 568–571 (2011).

[47] H. Liu, A.-P. Luo, F.-Z. Wang, R. Tang, M. Liu, Z.-C. Luo, W.-C. Xu, C.-J. Zhao, and H. Zhang, “Femtosecond pulse erbium-doped fiber laser by a few-layer MoS2 saturable absorber,” Opt. Lett. 39, 4591–4594 (2014).

[48] M. Liu, X.-W. Zheng, Y.-L. Qi, H. Liu, A.-P. Luo, Z.-C. Luo, W.-C. Xu, C.-J. Zhao, and H. Zhang, “Microfiber-based few-layer MoS2 saturable absorber for 25 GHz passively harmonic mode-locked fiber laser,” Opt. Express 22, 22841–22846 (2014).

[49] J. Du, Q. Wang, G. Jiang, C. Xu, C. Zhao, Y. Xiang, Y. Chen, S. Wen, and H. Zhang, “Ytterbium-doped fiber laser passively mode locked by few-layer molybdenum disulfide (MoS2) saturable absorber functioned with evanescent field interaction,” Sci. Rep. 4, 6346 (2014).

[50] R. Gordon, D. Yang, E. Crozier, D. Jiang, and R. Frindt, “Structures of exfoliated single layers of WS2, MoS2, and MoSe2 in aqueous suspension,” Phys. Rev. B 65, 125407 (2002).

[51] M. A. Py and R. R. Haering, “Structural destabilization induced by lithium intercalation in MoS2 and related compounds,” Can. J. Phys. 61, 76–84 (1983).

[52] L. Mattheiss, “Band structures of transition-metal-dichalcogenide layer compounds,” Phys. Rev. B 8, 3719–3740 (1973).

[53] J. N. Israelachvili, Intermolecular and Surface Forces (Academic, 2011).

[54] T. J. Mason, Sonochemistry (Oxford, 1999).

[55] K.-G. Zhou, M. Zhao, M.-J. Chang, Q. Wang, X.-Z. Wu, Y. Song, and H.-L. Zhang, “Size-dependent nonlinear optical properties of atomically thin transition metal dichalcogenide nanosheets,” Small 11, 634 (2015).

[56] Y. Feldman, E. Wasserman, D. Srolovitz, and R. Tenne, “Highrate, gas-phase growth of MoS2 nested inorganic fullerenes and nanotubes,” Science 267, 222–225 (1995).

[57] C. Lee, H. Yan, L. E. Brus, T. F. Heinz, J. Hone, and S. Ryu, “Anomalous lattice vibrations of single- and few-layer MoS2,” ACS Nano 4, 2695–2700 (2010).

[58] Y. Zhao, X. Luo, H. Li, J. Zhang, P. T. Araujo, C. K. Gan, J. Wu, H. Zhang, S. Y. Quek, M. S. Dresselhaus, and Q. Xiong, “Interlayer breathing and shear modes in few-trilayer MoS2 and WSe2,” Nano Lett. 13, 1007–1015 (2013).

[59] A. Molina-Sánchez and L. Wirtz, “Phonons in single-layer and few-layer MoS2 and WS2,” Phys. Rev. B 84, 155413 (2011).

[60] B. Chakraborty, H. S. S. R. Matte, A. K. Sood, and C. N. R. Rao, “Layer-dependent resonant Raman scattering of a few layer MoS2,” J. Raman Spectrosc. 44, 92–96 (2013).

[61] W. Zhang, J.-K. Huang, C.-H. Chen, Y.-H. Chang, Y.-J. Cheng, and L.-J. Li, “High-gain phototransistors based on a CVD MoS2 monolayer,” Adv. Mater. 25, 3456–3461 (2013).

[62] X. Zhang, W. Han, J. Wu, S. Milana, Y. Lu, Q. Li, A. Ferrari, and P. Tan, “Raman spectroscopy of shear and layer breathing modes in multilayer MoS2,” Phys. Rev. B 87, 115413 (2013).

[63] V. Nicolosi, M. Chhowalla, M. G. Kanatzidis, M. S. Strano, and J. N. Coleman, “Liquid exfoliation of layered materials,” Science 340, 1226419 (2013).

[64] F. Torrisi, T. Hasan, W. Wu, Z. Sun, A. Lombardo, T. S. Kulmala, G.-W. Hsieh, S. Jung, F. Bonaccorso, P. J. Paul, D. Chu, and A. C. Ferrari, “Inkjet-printed graphene electronics,” ACS Nano 6, 2992–3006 (2012).

[65] F. Withers, H. Yang, L. Britnell, A. P. Rooney, E. Lewis, A. Felten, C. R. Woods, V. S. Romaguera, T. Georgiou, A. Eckmann, Y. J. Kim, S. G. Yeates, S. J. Haigh, A. K. Geim, K. S. Novoselov, and C. Casiraghi, “Heterostructures produced from nanosheet-based inks,” Nano Lett. 14, 3987–3992 (2014).

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

[67] Z. Sun, T. Hasan, and A. C. Ferrari, “Ultrafast lasers mode-locked by nanotubes and graphene,” Physica E 44, 1082–1091 (2012).

[68] B. V. Cunning, C. L. Brown, and D. Kielpinski, “Low-loss flakegraphene saturable absorber mirror for laser mode-locking at sub-200-fs pulse duration,” Appl. Phys. Lett. 99, 261109 (2011).

[69] B. Xu, Y. Cheng, Y. Wang, Y. Huang, J. Peng, Z. Luo, H. Xu, Z. Cai, J. Weng, and R. Moncorgé, “Passively Q-switched Nd:YAlO3 nanosecond laser using MoS2 as saturable absorber,” Opt. Express 22, 28934–28940 (2014).

[70] R. J. Smith, P. J. King, M. Lotya, C. Wirtz, U. Khan, S. De, A. O’Neill, G. S. Duesberg, J. C. Grunlan, G. Moriarty, J. Chen, J. Wang, A. I. Minett, V. Nicolosi, and J. N. Coleman, “Large-scale exfoliation of inorganic layered compounds in aqueous surfactant solutions,” Adv. Mater. 23, 3944–3948 (2011).

[71] R. I. Woodward, E. J. R. Kelleher, T. H. Runcorn, S. V. Popov, F. Torrisi, R. C. T. Howe, and T. Hasan, “Q-switched fiber laser with MoS2 saturable absorber,” in CLEO: 2014, OSA Technical Digest (Optical Society of America, 2014), paper SM3H-6.

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

[73] M. Zhang, R. C. T. Howe, R. I. Woodward, E. J. R. Kelleher, F. Torrisi, G. Hu, S. V. Popov, J. R. Taylor, and T. Hasan, “Solution processed MoS2-PVA composite for sub-bandgap mode-locking of a wideband tunable ultrafast Er:fiber laser,” Nano Res., doi:10.1007/s12274-014-0637-2 (to be published)..

[74] Y. Huang, Z. Luo, Y. Li, M. Zhong, B. Xu, K. Che, H. Xu, Z. Cai, J. Peng, and J. Weng, “Widely-tunable, passively Q-switched erbium-doped fiber laser with few-layer MoS2 saturable absorber,” Opt. Express 22, 25258–25266 (2014).

[75] Z. Luo, Y. Huang, M. Zhong, Y. Li, J. Wu, B. Xu, H. Xu, Z. Cai, J. Peng, and J. Weng, “1-, 1.5-, and 2-um fiber lasers Q-switched by a broadband few-layer MoS2 saturable absorber,” J. Lightwave Technol. 32, 4679–4686 (2014).

[76] R. Khazaeinezhad, S. H. Kassani, T. Nazari, H. Jeong, J. Kim, K. Choi, J.-U. Lee, J. H. Kim, H. Cheong, D.-I. Yeom, and K. Oh, “Saturable optical absorption in MoS2 nano-sheet optically deposited on the optical fiber facet,” Opt. Commun. 335, 224–230 (2015).

[77] H. Xia, H. Li, C. Lan, C. Li, X. Zhang, S. Zhang, and Y. Liu, “Ultrafast erbium-doped fiber laser mode-locked by a CVD-grown molybdenum disulfide (MoS2) saturable absorber,” Opt. Express 22, 17341–17348 (2014).

[78] R. Khazaeizhad, S. H. Kassani, H. Jeong, D.-I. Yeom, and K. Oh, “Mode-locking of Er-doped fiber laser using a multilayer MoS2 thin film as a saturable absorber in both anomalous and normal dispersion regimes,” Opt. Express 22, 23732–23742 (2014).

[79] H. Li, H. Xia, C. Lan, C. Li, X. Zhang, J. Li, and Y. Liu, “Passively Q-switched erbium-doped fiber laser based on few-layer MoS2 saturable absorber,” IEEE Photon. Technol. Lett. 27, 69–72 (2015).

[80] A. R. Beal, J. C. Knights, and W. Y. Liang, “Transmission spectra of some transition metal dichalcogenides. II. Group VIA: trigonal prismatic coordination,” J. Phys. C 5, 3540–3551 (1972).

[81] R. A. Bromley, R. B. Murray, and A. D. Yoffe, “The band structures of some transition metal dichalcogenides: III. Group VIA : trigonal prism materials,” J. Phys. C 5, 759–778 (1972).

[82] H. Li, Q. Zhang, C. C. R. Yap, B. K. Tay, T. H. T. Edwin, A. Olivier, and D. Baillargeat, “From bulk to monolayer MoS2: evolution of Raman scattering,” Adv. Funct. Mater. 22, 1385–1390 (2012).

[83] T. Hasan, F. Torrisi, Z. Sun, D. Popa, V. Nicolosi, G. Privitera, F. Bonaccorso, and A. C. Ferrari, “Solution-phase exfoliation of graphite for ultrafast photonics,” Phys. Status Solidi B 247, 2953–2957 (2010).

[84] N. Kumar, S. Najmaei, Q. Cui, F. Ceballos, P. Ajayan, J. Lou, and H. Zhao, “Second harmonic microscopy of monolayer MoS2,” Phys. Rev. B 87, 161403 (2013).

[85] R. Wang, H.-C. Chien, J. Kumar, N. Kumar, H.-Y. Chiu, and H. Zhao, “Third-harmonic generation in ultrathin films of MoS2,” ACS Appl. Mater. Interfaces 6, 314–318 (2014).

[86] Y. Li, Y. Rao, K. F. Mak, Y. You, S. Wang, C. R. Dean, and T. F. Heinz, “Probing symmetry properties of few-layer MoS2 and h-BN by optical second-harmonic generation,” Nano Lett. 13, 3329–3333 (2013).

[87] R. Sundaram, M. Engel, A. Lombardo, R. Krupke, A. C. Ferrari, P. Avouris, and M. Steiner, “Electroluminescence in single layer MoS2,” Nano Lett. 13, 1416–1421 (2013).

[88] M. Sheik-Bahae, A. A. Said, T.-H. Wei, D. Hagan, and E. Van Stryland, “Sensitive measurement of optical nonlinearities using a single beam,” IEEE J. Quantum Electron. 26, 760–769 (1990).

[89] B. Taheri, H. Liu, B. Jassemnejad, D. Appling, R. C. Powell, and J. J. Song, “Intensity scan and two photon absorption and nonlinear refraction of C60 in toluene,” Appl. Phys. Lett. 68, 1317 (1996).

[90] R. F. Souza, M. A. R. C. Alencar, J. M. Hickmann, R. Kobayashi, and L. R. P. Kassab, “Femtosecond nonlinear optical properties of tellurite glasses,” Appl. Phys. Lett. 89, 171917 (2006).

[91] E. Garmire, “Resonant optical nonlinearities in semiconductors,” IEEE J. Sel. Top. Quantum Electron. 6, 1094–1110 (2000).

[92] T. R. Schibli, E. R. Thoen, F. X. K?rtner, and E. P. Ippen, “Suppression of Q-switched mode locking and break-up into multiple pulses by inverse saturable absorption,” Appl. Phys. B 70, S41–S49 (2000).

[93] R. Wang, B. A. Ruzicka, N. Kumar, M. Z. Bellus, H.-Y. Chiu, and H. Zhao, “Ultrafast and spatially resolved studies of charge carriers in atomically thin molybdenum disulfide,” Phys. Rev. B 86, 045406 (2012).

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

[95] Q. Ouyang, H. Yu, K. Zhang, and Y. Chen, “Saturable absorption and the changeover from saturable absorption to reverse saturable absorption of MoS2 nanoflake array films,” J. Mater. Chem. C 2, 6319–6325 (2014).

[96] P. Y. Yu and M. Cardona, Fundamentals of Semiconductors: Physics and Materials Properties (Springer, 2010).

[97] S. Kasap, Principles of Electronic Materials and Devices (McGraw-Hill, 2005).

[98] C. B. Roxlo, M. Daage, A. F. Rupper, and R. R. Chianelli, “Optical absorption and catalytic activity of molybdenum sulfide edge surfaces,” J. Catal. 100, 176–184 (1986).

[99] C. B. Roxlo, M. Daage, D. P. Leta, K. S. Liang, S. Rice, A. F. Ruppert, and R. R. Chianelli, “Catalytic defects at molybdenum disulfide “edge” planes,” Solid State Ionics 22, 97–104 (1986).

[100] C. B. Roxlo, “Bulk and surface optical absorption in molybdenum disulfide,” J. Vac. Sci. Technol. A 5, 555–557 (1987).

[101] X. Yin, Z. Ye, D. A. Chenet, Y. Ye, K. O’Brien, J. C. Hone, and X. Zhang, “Edge nonlinear optics on a MoS2 atomic monolayer,” Science Mag. 344(6183), 488–490 (2014).

[102] M. I. Demchuk, N. V. Kuleshov, and V. P. Mikhailov, “Saturable absorbers based on impurity and defect centers in crystals,” IEEE J. Quantum Electron. 30, 2120–2126 (1994).

[103] Z. Zhang, L. Qian, D. Fan, and X. Deng, “Gallium arsenide: a new material to accomplish passively mode-locked Nd:YAG laser,” Appl. Phys. Lett. 60, 419 (1992).

[104] M. E. Fermann and I. Hartl, “Ultrafast fibre lasers,” Nat. Photonics 7, 868–874 (2013).

[105] A. K. M. Newaz, D. Prasai, J. I. Ziegler, D. Caudel, S. Robinson, R. F. Haglund, Jr., and K. I. Bolotin, “Electrical control of optical properties of monolayer MoS2,” Solid State Commun. 155, 49–52 (2013).

[106] Z. Yin, H. Li, L. Jiang, Y. Shi, Y. Sun, G. Lu, Q. Zhang, X. Chen, and H. Zhang, “Single-layer MoS2 phototransistors,” ACS Nano 6, 74–80 (2012).

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

[108] M. Bernardi, M. Palummo, and J. C. Grossman, “Extraordinary sunlight absorption and one nanometer thick photovoltaics using two-dimensional monolayer materials,” Nano Lett. 13, 3664–3670 (2013).

[109] M.-L. Tsai, S.-H. Su, J.-K. Chang, D.-S. Tsai, C.-H. Chen, C.-I. Wu, L.-J. Li, L.-J. Chen, and J.-H. He, “Monolayer MoS2 heterojunction solar cells,” ACS Nano 8, 8317–8322 (2014).

[110] L. M. Malard, T. V. Alencar, A. P. M. Barboza, K. F. Mak, and A. M. de Paula, “Observation of intense second harmonic generation from MoS2 atomic crystals,” Phys. Rev. B 87, 201401(R) (2013).

[111] K. F. Mak, K. He, J. Shan, and T. F. Heinz, “Control of valley polarization in monolayer MoS2 by optical helicity,” Nat. Nanotechnol. 7, 494–498 (2012).

[112] H. Zeng, J. Dai, W. Yao, D. Xiao, and X. Cui, “Valley polarization in MoS2 monolayers by optical pumping,” Nat. Nanotechnol. 7, 490–493 (2012).

[113] T. Cao, G. Wang, W. Han, H. Ye, C. Zhu, J. Shi, Q. Niu, P. Tan, E. Wang, B. Liu, and J. Feng, “Valley-selective circular dichroism of monolayer molybdenum disulphide,” Nat. Commun. 3, 887 (2012).

[114] H. J. Conley, B. Wang, J. I. Ziegler, R. F. Haglund, S. T. Pantelides, and K. I. Bolotin, “Bandgap engineering of strained monolayer and bilayer MoS2,” Nano Lett. 13, 3626 (2013).

[115] K. Roy, M. Padmanabhan, S. Goswami, T. P. Sai, G. Ramalingam, S. Raghavan, and A. Ghosh, “Graphene-MoS2 hybrid structures for multifunctional photoresponsive memory devices,” Nat. Nanotechnol. 8, 826–830 (2013).

[116] W. Zhang, C.-P. Chuu, J.-K. Huang, C.-H. Chen, M.-L. Tsai, Y.-H. Chang, C.-T. Liang, Y.-Z. Chen, Y.-L. Chueh, J.-H. He, M.-Y. Chou, and L.-J. Li, “Ultrahigh-gain photodetectors based on atomically thin graphene-MoS2 heterostructures,” Sci. Rep. 4, 3826 (2014).

[117] G. Eda and S. A. Maier, “Two-dimensional crystals: managing light for optoelectronics,” ACS Nano 7, 5660–5665 (2013).

[118] N. Huo, J. Kang, Z. Wei, S.-S. Li, J. Li, and S.-H. Wei, “Novel and enhanced optoelectronic performances of multilayer MoS2WS2 heterostructure transistors,” Adv. Funct. Mater. 24, 7025–7031 (2014).

[119] H. Wang, F. Liu, W. Fu, Z. Fang, W. Zhou, and Z. Liu, “Twodimensional heterostructures: fabrication, characterization, and application,” Nanoscale 6, 12250–12272 (2014).

[120] Y. Y. Wang, F. Couny, P. S. Light, B. J. Mangan, and F. Benabid, “Compact and portable multiline UV and visible Raman lasers in hydrogen-filled HC-PCF,” Opt. Lett. 35, 1127–1129 (2010).

[121] D. J. Richardson, J. Nilsson, and W. A. Clarkson, “High power fiber lasers: current status and future perspectives,” J. Opt. Soc. Am. B 27, B63–B92 (2010).

[122] B. Orta?, M. Baumgartl, J. Limpert, and A. Tünnermann, “Approaching microjoule-level pulse energy with mode-locked femtosecond fiber lasers,” Opt. Lett. 34, 1585–1587 (2009).

[123] W. Renninger, A. Chong, and F. Wise, “Giant-chirp oscillators for short-pulse fiber amplifiers,” Opt. Lett. 33, 3025–3027 (2008).

[124] R. I. Woodward, E. J. R. Kelleher, T. H. Runcorn, S. Loranger, D. Popa, V. J. Wittwer, A. C. Ferrari, S. V. Popov, R. Kashyap, and J. R. Taylor, “Fiber grating compression of giant-chirped nanosecond pulses from an ultra-long nanotube mode-locked fiber laser,” Opt. Lett. 40, 387–390 (2015).

[125] A. Giesen and J. Speiser, “Fifteen years of work on thin-disk lasers: results and scaling laws,” IEEE J. Sel. Top. Quantum Electron. 13, 598–609 (2007).

[126] K. Wu, X. Zhang, J. Wang, X. Li, and J. Chen, “WS2 as a saturable absorber for ultrafast photonic applications of mode-locked and Q-switched lasers,” arXiv:1411.5777 (2014).

[127] S. H. Kassani, R. Khazaeizhad, H. Jeong, D.-I. Yeom, and K. Oh, “All-fiber Er-doped Q-switched laser based on tungsten disulfide saturable absorber,” Opt. Mater. Express 5, 373–379 (2015).

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

[129] P. Yan, A. Liu, Y. Chen, H. Chen, S. Ruan, S. Chen, I. L. Li, H. Yang, J. Hu, and G. Cao, “Microfiber-based WS2-film saturable absorber for ultra-fast photonics,” Opt. Mater. Express 5, 479–489 (2015).