1T-polytype tantalum disulfide(1T-TaS2),an emerging strongly correlated material,features a narrow bandgap of 0.2 eV,bridging the gap between zero-bandgap graphene and large-bandgap 2D nonlinear optical(NLO)materials.Combined with its intense light absorption,high carrier concentration,and high mobility,1T-TaS2 shows considerable potential for applications in broadband optoelectronic devices.However,its NLO character-istics and related applications have rarely been explored.Here,1T-TaS2 nanosheets are prepared by chemical vapor deposition.The ultrafast carrier dynamics in the 400-1100 nm range and broadband NLO performance in the 515-2500 nm range are systematically studied using femtosecond lasers.An obvious saturable absorption phenomenon is observed in the visible to IR range.The nonlinear absorption coefficient is measured to be-22.60±0.52 cmMW-1 under 1030 nm,which is larger than that of other typical 2D saturable absorber(SA)materials(graphene,black phosphorus,and MoS2)under similar experimental conditions.Based on these findings,using 1T-TaS2 as a new SA,passively Q-switched laser operations are successfully performed at 1.06,1.34,and 1.94 μm.The results highlight the promise of 1T-TaS2 for broadband optical modulators and provide a potential candidate material system for mid-IR nonlinear optical applications.

MENGXIA WANG;HAILONG QIU;TIANWEN YANG;ZHENGPING WANG;CHUANRUI ZHAO;YUANAN ZHAO;TING YU;YUYAO JIANG;MEILING CHEN;YAFEI LIAN;GE ZHANG;HONGJUN LIU;ZHANGGUI HU;JIANDA SHAO

Laboratory of Thin Film Optics,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;Tianjin Key Laboratory of Functional Crystal Materials,Institute of Functional Crystal,Tianjin University of Technology,Tianjin 300384,China;State Key Laboratory of Crystal Materials,Shandong University,Jinan 250100,China;Laboratory of High Power Fiber Laser Technology,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;College of Science,Shanghai University,Shanghai 200444,China;Hangzhou Institute for Advanced Study,University of Chinese Academy of Sciences,Hangzhou 310024,China

光子学研究（英文）

[1]MENGXIA WANG;HAILONG QIU;TIANWEN YANG;ZHENGPING WANG;CHUANRUI ZHAO;YUANAN ZHAO;TING YU;YUYAO JIANG;MEILING CHEN;YAFEI LIAN;GE ZHANG;HONGJUN LIU;ZHANGGUI HU;JIANDA SHAO-.Broadband 1T-polytype tantalum disulfide saturable absorber for solid-state bulk lasers)[J].光子学研究（英文）,2022(09):2122-2132

polytype,cmMW

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