We report Q-switched and mode-locked erbium-doped all-fiber lasers using ternary ReS_(2(1-x))Se_(2x) as saturable absorbers(SAs). The modulation depth and saturable intensity of the film SA are 1.8% and 0.046 MW∕cm2....We report Q-switched and mode-locked erbium-doped all-fiber lasers using ternary ReS_(2(1-x))Se_(2x) as saturable absorbers(SAs). The modulation depth and saturable intensity of the film SA are 1.8% and 0.046 MW∕cm2.In Q-switched mechanism output, the pulse was centered at 1531.1 nm with maximum pulse energy and minimum pulse width of 28.29 nJ and 1.07 μs, respectively. In mode-locked operation, the pulse was centered at1561.15 nm with pulse width of 888 fs, repetition rate of 2.95 MHz, and maximum pulse energy of 0.275 nJ. To the best of our knowledge, this is the first report on the mode-locked Er^(3+)-doped fiber laser using ternary transition metal dichalcogenides. This work suggests prospective 2 D-material SAs can be widely used in versatile fields due to their attractive optoelectronic and tunable energy bandgap properties.展开更多
Accurate and clear bioimaging is crucial in the field of medical diagnosis.High-quality bioimaging requires to avoid the effects of ambient light as well as the absorption of biological tissues.Nearinfrared(NIR)narrow...Accurate and clear bioimaging is crucial in the field of medical diagnosis.High-quality bioimaging requires to avoid the effects of ambient light as well as the absorption of biological tissues.Nearinfrared(NIR)narrowband detectors located at wavelength from 650 to 900 nm can meet these requirements;thus,they are the potential solution.In this work,we construct a filter-free and self-power NIR narrowband photodetector based on the structure of n-CdSe/p-Sb_(2)(S_(1-x),Se_(x))_(3)heterojunction,and achieve a narrow spectral response at 735 nm with a full width at half-maximum of 35.3 nm in the detector.Further,the imaging characteristics of the NIR narrowband detector are explored,verifying the ability to narrowband detection and imaging.This filter-free and self-power NIR narrowband detector shows considerable promise in real-life applications.展开更多
Transition metal dichalcogenide(TMD)alloys and heterostructures are attracting increasing attention thanks to their unique electronic,optical,and interfacial properties.However,the growth fundamental of TMD alloys and...Transition metal dichalcogenide(TMD)alloys and heterostructures are attracting increasing attention thanks to their unique electronic,optical,and interfacial properties.However,the growth fundamental of TMD alloys and heterostructures during one-step growth is still beyond understanding.Here,thermogravimetric(TG/DTG)technology is introduced to predict the evolution of the precursor(MoO_(3)and WO_(3))concentration in the vapor during growth.We establish the correlation between precursor concentration and the corresponding growth behavior.TG/DTG predication suggests that tuning precursor temperature and powder ratio can alter their concentration in the vapor,well explaining the formation of Mo_(x)W_(1-x)Se_(2) alloy or MoSe_(2)-WSe_(2) heterostructure at different growth conditions.Based on the TG/DTG analysis,we further design and grow a complex MoSe_(2)-Mo_(x)W_(1-x)Se_(2)-WSe_(2) heterostructure and Mo_(x)W_(1-x)Se_(2) monolayer alloys,confirming the validity of TG/DTG prediction in TMD crystal synthesis.Thus,employing TG/DTG to predict the synthesis of two-dimensional materials is of importance to understand the TMD growth behavior and provide guidance to the desired TMD heterostructure formation for future photoelectric devices.展开更多
基金National Key R&D Program of China(2018YFB1107200)National Natural Science Foundation of China(NSFC)(61675158,21673058)+1 种基金Chinese Academy of Sciences Key Project(CAS Key Project)(QYZDBSSW-SYS031)Chinese Academy of Sciences(CAS)(XDB30000000)
文摘We report Q-switched and mode-locked erbium-doped all-fiber lasers using ternary ReS_(2(1-x))Se_(2x) as saturable absorbers(SAs). The modulation depth and saturable intensity of the film SA are 1.8% and 0.046 MW∕cm2.In Q-switched mechanism output, the pulse was centered at 1531.1 nm with maximum pulse energy and minimum pulse width of 28.29 nJ and 1.07 μs, respectively. In mode-locked operation, the pulse was centered at1561.15 nm with pulse width of 888 fs, repetition rate of 2.95 MHz, and maximum pulse energy of 0.275 nJ. To the best of our knowledge, this is the first report on the mode-locked Er^(3+)-doped fiber laser using ternary transition metal dichalcogenides. This work suggests prospective 2 D-material SAs can be widely used in versatile fields due to their attractive optoelectronic and tunable energy bandgap properties.
基金China Postdoctoral Science Foundation Project,Grant/Award Numbers:2020M680101,2021T140233Fundamental Research Funds for the Central Universities,Grant/Award Number:2021XXJS028+2 种基金National Natural Science Foundation of China,Grant/Award Numbers:61725401,61904058,62050039the Graduates'Innovation Fund of Huazhong University of Science and Technology,Grant/Award Number:2021yjsCXCY051the National Key R&D Program of China,Grant/Award Number:2016YFA0204000。
文摘Accurate and clear bioimaging is crucial in the field of medical diagnosis.High-quality bioimaging requires to avoid the effects of ambient light as well as the absorption of biological tissues.Nearinfrared(NIR)narrowband detectors located at wavelength from 650 to 900 nm can meet these requirements;thus,they are the potential solution.In this work,we construct a filter-free and self-power NIR narrowband photodetector based on the structure of n-CdSe/p-Sb_(2)(S_(1-x),Se_(x))_(3)heterojunction,and achieve a narrow spectral response at 735 nm with a full width at half-maximum of 35.3 nm in the detector.Further,the imaging characteristics of the NIR narrowband detector are explored,verifying the ability to narrowband detection and imaging.This filter-free and self-power NIR narrowband detector shows considerable promise in real-life applications.
基金The National Natural Science Foundation of Giina(Nos.51702368,61974166,and 11674401)the Natural Science Foundation of Hunan Province(Nos.2018JJ3684 and 2019JJ40358)+1 种基金Innovation-Driven Project of Central South University(No.2018CX045)the Mechanism Research Funds for the Central South University(No.1053320181264)are acknowledged for financial support.
文摘Transition metal dichalcogenide(TMD)alloys and heterostructures are attracting increasing attention thanks to their unique electronic,optical,and interfacial properties.However,the growth fundamental of TMD alloys and heterostructures during one-step growth is still beyond understanding.Here,thermogravimetric(TG/DTG)technology is introduced to predict the evolution of the precursor(MoO_(3)and WO_(3))concentration in the vapor during growth.We establish the correlation between precursor concentration and the corresponding growth behavior.TG/DTG predication suggests that tuning precursor temperature and powder ratio can alter their concentration in the vapor,well explaining the formation of Mo_(x)W_(1-x)Se_(2) alloy or MoSe_(2)-WSe_(2) heterostructure at different growth conditions.Based on the TG/DTG analysis,we further design and grow a complex MoSe_(2)-Mo_(x)W_(1-x)Se_(2)-WSe_(2) heterostructure and Mo_(x)W_(1-x)Se_(2) monolayer alloys,confirming the validity of TG/DTG prediction in TMD crystal synthesis.Thus,employing TG/DTG to predict the synthesis of two-dimensional materials is of importance to understand the TMD growth behavior and provide guidance to the desired TMD heterostructure formation for future photoelectric devices.
