Highly stable and repeatable femtosecond soliton pulse generation from saturable absorbers based on two-dimensional Cu_3−xP nanocrystals

Abstract

Heavily doped colloidal plasmonic nanocrystals have attracted great attention because of their lower and adjustable free carrier densities and tunable localized surface plasmonic resonance bands in the spectral range from near-infra to mid-infra wavelengths. With its plasmon-enhanced optical nonlinearity, this new family of plasmonic materials shows a huge potential for nonlinear optical applications, such as ultrafast switching, nonlinear sensing, and pulse laser generation. Cu_3−xP nanocrystals were previously shown to have a strong saturable absorption at the plasmonic resonance, which enabled high-energy Q-switched fiber lasers with 6.1 µs pulse duration. This work demonstrates that both high-quality mode-locked and Q-switched pulses at 1560 nm can be generated by evanescently incorporating two-dimensional (2D) Cu_3−xP nanocrystals onto a D-shaped optical fiber as an effective saturable absorber. The 3 dB bandwidth of the mode-locking optical spectrum is as broad as 7.3 nm, and the corresponding pulse duration can reach 423 fs. The repetition rate of the Q-switching pulses is higher than 80 kHz. Moreover, the largest pulse energy is more than 120 µJ. Note that laser characteristics are highly stable and repeatable based on the results of over 20 devices. This work may trigger further investigations on heavily doped plasmonic 2D nanocrystals as a next-generation, inexpensive, and solution-processed element for fascinating photonics and optoelectronics applications.

Graphical abstract

Keywords

plasmonic semiconductors / fiber laser / mode-locking / ultrafast generation

References

[1] Martinez A, Sun Z. Nanotube and graphene saturable absorbers for fibre lasers. Nature Photonics, 2013, 7(11): 842–845

[2] Haus H A. Mode-locking of lasers. IEEE Journal of Selected Topics in Quantum Electronics, 2000, 6(6): 1173–1185

[3] Keller U, Weingarten K J, Kartner F X, Kopf D, Braun B, Jung I D, Fluck R, Honninger C, Matuschek N, Der Au J A. Semiconductor saturable absorber mirrors (SESAM’s) for femtosecond to nanosecond pulse generation in solid-state lasers. IEEE Journal of Selected Topics in Quantum Electronics, 1996, 2(3): 435–453

[4] Autere A, Jussila H, Dai Y, Wang Y, Lipsanen H, Sun Z. Nonlinear optics with 2D layered materials. Advanced Materials, 2018, 30(24): 1705963

[5] Sun Z, Martinez A, Wang F. Optical modulators with 2D layered materials. Nature Photonics, 2016, 10(4): 227–238

[6] Bao Q, Zhang H, Wang Y, Ni Z, Yan Y, Shen Z X, Loh K P, Tang D Y. Atomic-layer graphene as a saturable absorber for ultrafast pulsed lasers. Advanced Functional Materials, 2009, 19(19): 3077–3083

[7] Shi H, Yan R, Bertolazzi S, Brivio J, Gao B, Kis A, Jena D, Xing H G, Huang L. Exciton dynamics in suspended monolayer and few-layer MoS₂ 2D crystals. ACS Nano, 2013, 7(2): 1072–1080

[8] Woodward R I, Kelleher E J. 2D saturable absorbers for fibre lasers. Applied Sciences, 2015, 5(4): 1440–1456

[9] Martinez A, Yamashita S. 10 GHz fundamental mode fiber laser using a graphene saturable absorber. Applied Physics Letters, 2012, 101(4): 041118

[10] Liu W, Pang L, Han H, Liu M, Lei M, Fang S, Teng H, Wei Z. Tungsten disulfide saturable absorbers for 67 fs mode-locked erbium-doped fiber lasers. Optics Express, 2017, 25(3): 2950–2959

[11] Jin X, Hu G, Zhang M, Hu Y, Albrow-Owen T, Howe R C T, Wu T C, Wu Q, Zheng Z, Hasan T. 102 fs pulse generation from a long-term stable, inkjet-printed black phosphorus-mode-locked fiber laser. Optics Express, 2018, 26(10): 12506–12513

[12] Jiang T, Yin K, Wang C, You J, Ouyang H, Miao R, Zhang C, Wei K, Li H, Chen H, Zhang R, Zheng X, Xu Z, Cheng X, Zhang H. Ultrafast fiber lasers mode-locked by two-dimensional materials: review and prospect. Photonics Research, 2020, 8(1): 78–90

[13] Li P, Chen Y, Yang T, Wang Z, Lin H, Xu Y, Li L, Mu H, Shivananju B N, Zhang Y, Zhang Q, Pan A, Li S, Tang D, Jia B, Zhang H, Bao Q. Two-dimensional CH₃NH₃PbI₃ perovskite nanosheets for ultrafast pulsed fiber lasers. ACS Applied Materials & Interfaces, 2017, 9(14): 12759–12765

[14] Ge Y, Zhu Z, Xu Y, Chen Y, Chen S, Liang Z, Song Y, Zou Y, Zeng H, Xu S, Zhang H, Fan D. Broadband nonlinear photoresponse of 2D TiS₂ for ultrashort pulse generation and all-optical thresholding devices. Advanced Optical Materials, 2018, 6(4): 1701166

[15] Guo B, Wang S H, Wu Z X, Wang Z X, Wang D H, Huang H, Zhang F, Ge Y Q, Zhang H. Sub-200 fs soliton mode-locked fiber laser based on bismuthene saturable absorber. Optics Express, 2018, 26(18): 22750–22760

[16] Kou L Z, Tan X, Ma Y D, Tahini H, Zhou L J, Sun Z Q, Du A J, Chen C F, Smith S C. Tetragonal bismuth bilayer: a stable and robust quantum spin hall insulator. 2D Materials, 2015, 4: 045010

[17] Comin A, Manna L. New materials for tunable plasmonic colloidal nanocrystals. Chemical Society Reviews, 2014, 43(11): 3957–3975

[18] Liu X, Swihart M T. Heavily-doped colloidal semiconductor and metal oxide nanocrystals: an emerging new class of plasmonic nanomaterials. Chemical Society Reviews, 2014, 43(11): 3908–3920

[19] Liu Z, Mu H, Xiao S, Wang R, Wang Z, Wang W, Wang Y, Zhu X, Lu K, Zhang H, Lee S T, Bao Q, Ma W. Pulsed lasers employing solution-processed plasmonic Cu_3−xP colloidal nanocrystals. Advanced Materials, 2016, 28(18): 3535–3542

[20] Scotognella F, Della Valle G, Srimath Kandada A R, Dorfs D, Zavelani-Rossi M, Conforti M, Miszta K, Comin A, Korobchevskaya K, Lanzani G, Manna L, Tassone F. Plasmon dynamics in colloidal Cu_2−xSe nanocrystals. Nano Letters, 2011, 11(11): 4711–4717

[21] Kriegel I, Jiang C, Rodríguez-Fernández J, Schaller R D, Talapin D V, da Como E, Feldmann J. Tuning the excitonic and plasmonic properties of copper chalcogenide nanocrystals. Journal of the American Chemical Society, 2012, 134(3): 1583–1590

[22] Luther J M, Jain P K, Ewers T, Alivisatos A P. Localized surface plasmon resonances arising from free carriers in doped quantum dots. Nature Materials, 2011, 10(5): 361–366

[23] Hamanaka Y, Hirose T, Yamada K, Kuzuya T. Plasmonic enhancement of third-order nonlinear optical susceptibilities in self-doped Cu_2−xS nanoparticles. Optical Materials Express, 2016, 6(12): 3838–3848

[24] Liu X, Guo Q, Qiu J. Emerging low-dimensional materials for nonlinear optics and ultrafast photonics. Advanced Materials, 2017, 29(14): 1605886

[25] Henkes A E, Schaak R E. Trioctylphosphine: a general phosphorus source for the low-temperature conversion of metals into metal phosphides. Chemistry of Materials, 2007, 19(17): 4234–4242

[26] Hsu S W, Ngo C, Tao A R. Tunable and directional plasmonic coupling within semiconductor nanodisk assemblies. Nano Letters, 2014, 14(5): 2372–2380

[27] Popa D, Sun Z, Hasan T, Torrisi F, Wang F, Ferrari A C. Graphene Q-switched, tunable fiber laser. Applied Physics Letters, 2011, 98(7): 073106

Acknowledgements

We acknowledge the support from the National Key Research & Development Program (No. 2016YFA0201902), Shenzhen Nanshan District Pilotage Team Program (No. LHTD20170006) and Australian Research Council (ARC, FT150100450, IH150100006, and CE170100039). B.S. acknowledges the funding support from China Postdoctoral Science Foundation Grant (No. 217M622758). This work was performed in part at the Melbourne Centre for Nanofabrication (MCN) in the Victorian Node of the Australian National Fabrication Facility (ANFF).

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