A novel Nd, La：SrF_2 disordered crystal is prepared, and its continuous-wave wavelength tuning operation is performed for the first time. Employing a surface plasmon resonance（SPR） based gold nanobipyramids（G-NBPs...A novel Nd, La：SrF_2 disordered crystal is prepared, and its continuous-wave wavelength tuning operation is performed for the first time. Employing a surface plasmon resonance（SPR） based gold nanobipyramids（G-NBPs） saturable absorber,we obtain a compact diode-pumped passively Q-switched Nd, La：SrF_2 laser. The stable Q-switched pulse operates with the shortest pulse duration of 1.15 μs and the maximum repetition rate of 41 k Hz. The corresponding single pulse energy is 2.24 μJ. The results indicate that G-NBPs could be a promising saturable absorber applied to the diode-pumped solid state lasers（DPSSLs）.展开更多
This paper presents an efficient image feature representation method, namely angle structure descriptor(ASD), which is built based on the angle structures of images. According to the diversity in directions, angle str...This paper presents an efficient image feature representation method, namely angle structure descriptor(ASD), which is built based on the angle structures of images. According to the diversity in directions, angle structures are defined in local blocks. Combining color information in HSV color space, we use angle structures to detect images. The internal correlations between neighboring pixels in angle structures are explored to form a feature vector. With angle structures as bridges, ASD extracts image features by integrating multiple information as a whole, such as color, texture, shape and spatial layout information. In addition, the proposed algorithm is efficient for image retrieval without any clustering implementation or model training. Experimental results demonstrate that ASD outperforms the other related algorithms.展开更多
The excellent optical properties of MXene provide new opportunities for short-pulse lasers. A diode-pumped passively Q-switched laser at 1.3 μm wavelength with MXene Ti3C2Tx as saturable absorber was achieved for the...The excellent optical properties of MXene provide new opportunities for short-pulse lasers. A diode-pumped passively Q-switched laser at 1.3 μm wavelength with MXene Ti3C2Tx as saturable absorber was achieved for the first time. The stable passively Q-switched laser has 454 ns pulse width and 162 kHz repetition rate at 4.5 W incident pumped power. The experimental results show that the MXene Ti3C2Tx saturable absorber can be used as an optical modulator to generate short pulse lasers in a solid-state laser field.展开更多
We report the fabrication of a planar waveguide in the Nd：Bi_（12）SiO_（20） crystal by multi-energy C ions at room temperature. The waveguide is annealed at 200℃, 260℃, and 300℃ in succession each for 30 min in ...We report the fabrication of a planar waveguide in the Nd：Bi_（12）SiO_（20） crystal by multi-energy C ions at room temperature. The waveguide is annealed at 200℃, 260℃, and 300℃ in succession each for 30 min in an open oven. The effective refractive index profiles at transverse electric（TE） polarization are stable after the annealing treatments. Damage distribution for multi-energy C ion implanted in Nd：Bi_（12）SiO_（20） crystal is calculated by SRIM 2010. The Raman and fluorescence spectra of the Nd：Bi_（12）SiO_（20） crystal are collected by an excitation beam at 633 nm and 473 nm, respectively. The results indicate the stabilization of the optical waveguide in Nd：Bi_（12）SiO_（20） crystal.展开更多
In this paper, tin disulfide （SnS2）, a two-dimensional （2D） n-type direct bandgap layered metal dichalcogenide with a gap value of 2.24 eV, was employed as a saturable absorber. Its appearance and nonlinear satura...In this paper, tin disulfide （SnS2）, a two-dimensional （2D） n-type direct bandgap layered metal dichalcogenide with a gap value of 2.24 eV, was employed as a saturable absorber. Its appearance and nonlinear saturable ab- sorption characteristics were also investigated experimentally. SnSz-PVA （polyvinyl alcohol） film was successfully prepared and employed as a mode-locker for achieving a mode-locked Er-doped fiber laser with a pulse width of 623 fs at a pulse repetition rate of 29.33 MHz. The results prove that SnS2 nanosheets will have wide potential ultrafast photonic applications due to their suitable bandgap value and excellent nonlinear saturable absorption characteristics.展开更多
Bismuth nanosheets(Bi-NSs) were successfully prepared and employed as saturable absorbers to generate a diodepumped dual-wavelength Er^(3+):SrF_2 laser in the mid-infrared region. Q-switched pulses with a maximum outp...Bismuth nanosheets(Bi-NSs) were successfully prepared and employed as saturable absorbers to generate a diodepumped dual-wavelength Er^(3+):SrF_2 laser in the mid-infrared region. Q-switched pulses with a maximum output power of 0.226 W were obtained at an absorbed pump power of 1.97 W. A repetition rate of 56.20 kHz and a minimum pulse duration of 980 ns were achieved. To the best of our knowledge, we present the first application of Bi-NSs in a mid-infrared all-solid-state laser. The results prove that Bi-NSs may be applied as an optical modulator in mid-infrared photonic devices or as a mode-locker and Q-switcher.展开更多
As a novel one-atom-thick carbon allotrope,graphdiyne(GDY)has attracted wide interest in two-dimensional materials owing to its unique feature with a planar layer comprising sp2-and sp-hybridized carbon atoms and a di...As a novel one-atom-thick carbon allotrope,graphdiyne(GDY)has attracted wide interest in two-dimensional materials owing to its unique feature with a planar layer comprising sp2-and sp-hybridized carbon atoms and a direct natural bandgap.A high-quality saturable absorber(SA)based on GDY was successfully fabricated,and the nonlinear saturable absorption properties were investigated.A compact diode-pumped solid-state passively Q-switched laser based on the as-prepared GDY-SA could be operated at 2µm.The Q-switched laser delivered a maximum average output power of 1.29 W at a central wavelength of 1908.41 nm with up to 54.8%slope efficiency.A repetition rate of 91.58 kHz and single pulse energy of 23.08µJ were obtained.This work is the first application of GDY as an SA to generate all-solid-state pulsed lasers.These results indicate that GDY is a promising SA for solid-state pulsed lasers and has further application potential for ultrafast photonic devices in the 2-µm region.展开更多
Workload consolidation is a common method to improve the resource utilization in clusters or data centers. In order to achieve efficient workload consolidation, the runtime characteristics of a program should be taken...Workload consolidation is a common method to improve the resource utilization in clusters or data centers. In order to achieve efficient workload consolidation, the runtime characteristics of a program should be taken into con-sideration in scheduling. In this paper, we propose a novel index system for efficiently describing the program runtime characteristics. With the help of this index system, programs can be classified by the following runtime characteristics: 1) dependence to multi-dimensional resources including CPU, disk I/O, memory and network I/O;and 2) impact and vulnerability to resource sharing embodied by resource usage and resource sensitivity. In order to verify the effectiveness of this novel index system in workload consolidation, a scheduling strategy, Sche-index, using the new index system for workload consolidation is proposed. Experiment results show that compared with traditional least-loaded scheduling strategy, Sche-index can improve both program performance and system resource utilization significantly.展开更多
A diode-pumped Tm:YLF passively Q-switched laser at 2μm was first demonstrated by using graphene oxide(GO)as a saturable absorber(SA).In this letter,continuous-wave(CW)laser and pulse laser performances were studied ...A diode-pumped Tm:YLF passively Q-switched laser at 2μm was first demonstrated by using graphene oxide(GO)as a saturable absorber(SA).In this letter,continuous-wave(CW)laser and pulse laser performances were studied meticulously and systematically.It reasonably showed the dependence of the pulse duration,pulse energy,and pulse repetition rate on the absorbed power.A maximum repetition rate of 38.33 kHz and a single pulse energy of 9.89μJ were obtained.展开更多
Using a novel silver nanorods absorber with a localized surface plasmon resonance absorption peak at 1.06μm,we obtain a diode-pumped passively Q-switched(PQS)Nd,Gd:CaF_(2) disordered crystal laser output.Its PQS puls...Using a novel silver nanorods absorber with a localized surface plasmon resonance absorption peak at 1.06μm,we obtain a diode-pumped passively Q-switched(PQS)Nd,Gd:CaF_(2) disordered crystal laser output.Its PQS pulse laser performances are studied comprehensively and systematically in this Letter.The single pulse energy and peak power can be attained to 2.15μJ and 2.06 W,respectively.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61475089,51432007,and 61422511)
文摘A novel Nd, La：SrF_2 disordered crystal is prepared, and its continuous-wave wavelength tuning operation is performed for the first time. Employing a surface plasmon resonance（SPR） based gold nanobipyramids（G-NBPs） saturable absorber,we obtain a compact diode-pumped passively Q-switched Nd, La：SrF_2 laser. The stable Q-switched pulse operates with the shortest pulse duration of 1.15 μs and the maximum repetition rate of 41 k Hz. The corresponding single pulse energy is 2.24 μJ. The results indicate that G-NBPs could be a promising saturable absorber applied to the diode-pumped solid state lasers（DPSSLs）.
基金supported by the National Natural Science Foundation of China (No.61170145, 61373081, 61402268, 61401260, 61572298)the Technology and Development Project of Shandong (No.2013GGX10125)+1 种基金the Natural Science Foundation of Shandong China (No.BS2014DX006, ZR2014FM012)the Taishan Scholar Project of Shandong, China
文摘This paper presents an efficient image feature representation method, namely angle structure descriptor(ASD), which is built based on the angle structures of images. According to the diversity in directions, angle structures are defined in local blocks. Combining color information in HSV color space, we use angle structures to detect images. The internal correlations between neighboring pixels in angle structures are explored to form a feature vector. With angle structures as bridges, ASD extracts image features by integrating multiple information as a whole, such as color, texture, shape and spatial layout information. In addition, the proposed algorithm is efficient for image retrieval without any clustering implementation or model training. Experimental results demonstrate that ASD outperforms the other related algorithms.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61475089 and 61435010)the Science and Technology Planning Project of Guangdong Province,China(Grant No.2016B050501005)the Science and Technology Innovation Commission of Shenzhen,China(Grant No.KQTD2015032416270385)
文摘The excellent optical properties of MXene provide new opportunities for short-pulse lasers. A diode-pumped passively Q-switched laser at 1.3 μm wavelength with MXene Ti3C2Tx as saturable absorber was achieved for the first time. The stable passively Q-switched laser has 454 ns pulse width and 162 kHz repetition rate at 4.5 W incident pumped power. The experimental results show that the MXene Ti3C2Tx saturable absorber can be used as an optical modulator to generate short pulse lasers in a solid-state laser field.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11404194 and 11274188)the Promotive Research Fund for Excellent Young and Middle-aged Scientisits of Shandong Province,China(Grant No.BS2015SF003)+3 种基金the China Postdoctoral Science Foundation(Grant Nos.2015M582053 and 2016T90609)the Qingdao Municipal Postdoctoral Application Research Project,China(Grant No.2015131)the State Key Laboratory of Nuclear Physics and Technology at Peking University,Chinathe State Key Laboratory of Crystal Materials and Key Laboratory of Particle Physics and Particle Irradiation(MOE)at Shandong University,China
文摘We report the fabrication of a planar waveguide in the Nd：Bi_（12）SiO_（20） crystal by multi-energy C ions at room temperature. The waveguide is annealed at 200℃, 260℃, and 300℃ in succession each for 30 min in an open oven. The effective refractive index profiles at transverse electric（TE） polarization are stable after the annealing treatments. Damage distribution for multi-energy C ion implanted in Nd：Bi_（12）SiO_（20） crystal is calculated by SRIM 2010. The Raman and fluorescence spectra of the Nd：Bi_（12）SiO_（20） crystal are collected by an excitation beam at 633 nm and 473 nm, respectively. The results indicate the stabilization of the optical waveguide in Nd：Bi_（12）SiO_（20） crystal.
基金National Natural Science Foundation of China(NSFC)(11474187,61205174,61475089)China Postdoctoral Science Foundation(2016M602177)Natural Science Foundation of Shandong Province,China(ZR2014FM028,ZR2016FP01)
文摘In this paper, tin disulfide （SnS2）, a two-dimensional （2D） n-type direct bandgap layered metal dichalcogenide with a gap value of 2.24 eV, was employed as a saturable absorber. Its appearance and nonlinear saturable ab- sorption characteristics were also investigated experimentally. SnSz-PVA （polyvinyl alcohol） film was successfully prepared and employed as a mode-locker for achieving a mode-locked Er-doped fiber laser with a pulse width of 623 fs at a pulse repetition rate of 29.33 MHz. The results prove that SnS2 nanosheets will have wide potential ultrafast photonic applications due to their suitable bandgap value and excellent nonlinear saturable absorption characteristics.
基金National Natural Science Foundation of China(NSFC)(61475089,61435010,61635012)Development Projects of Shandong Province Science and Technology(2017GGX30102)+2 种基金National Key Research and Development Program of China(2016YFB0701002)Science and Technology Planning Project of Guangdong Province(2016B050501005)Science and Technology Innovation Commission of Shenzhen(KQTD2015032416270385)
文摘Bismuth nanosheets(Bi-NSs) were successfully prepared and employed as saturable absorbers to generate a diodepumped dual-wavelength Er^(3+):SrF_2 laser in the mid-infrared region. Q-switched pulses with a maximum output power of 0.226 W were obtained at an absorbed pump power of 1.97 W. A repetition rate of 56.20 kHz and a minimum pulse duration of 980 ns were achieved. To the best of our knowledge, we present the first application of Bi-NSs in a mid-infrared all-solid-state laser. The results prove that Bi-NSs may be applied as an optical modulator in mid-infrared photonic devices or as a mode-locker and Q-switcher.
基金financially supported by the National Natural Science Foundation of China (11974220, 61635012,61875138, 61961136001, and U1801254)the State Key Research Development Program of China (2019YFB2203503)
文摘As a novel one-atom-thick carbon allotrope,graphdiyne(GDY)has attracted wide interest in two-dimensional materials owing to its unique feature with a planar layer comprising sp2-and sp-hybridized carbon atoms and a direct natural bandgap.A high-quality saturable absorber(SA)based on GDY was successfully fabricated,and the nonlinear saturable absorption properties were investigated.A compact diode-pumped solid-state passively Q-switched laser based on the as-prepared GDY-SA could be operated at 2µm.The Q-switched laser delivered a maximum average output power of 1.29 W at a central wavelength of 1908.41 nm with up to 54.8%slope efficiency.A repetition rate of 91.58 kHz and single pulse energy of 23.08µJ were obtained.This work is the first application of GDY as an SA to generate all-solid-state pulsed lasers.These results indicate that GDY is a promising SA for solid-state pulsed lasers and has further application potential for ultrafast photonic devices in the 2-µm region.
基金National Key Research and Development Program of China (2016YFB1000503)the National Natural Science Foundation of China (Grant Nos. 61133004, 61361126011, 61502019, 61732002, 61373081, 61772322)+1 种基金China Postdoctoral Science Foundation (2017M622263)Natural Science Foundation of Shandong Province (ZR2015PF006).
文摘Workload consolidation is a common method to improve the resource utilization in clusters or data centers. In order to achieve efficient workload consolidation, the runtime characteristics of a program should be taken into con-sideration in scheduling. In this paper, we propose a novel index system for efficiently describing the program runtime characteristics. With the help of this index system, programs can be classified by the following runtime characteristics: 1) dependence to multi-dimensional resources including CPU, disk I/O, memory and network I/O;and 2) impact and vulnerability to resource sharing embodied by resource usage and resource sensitivity. In order to verify the effectiveness of this novel index system in workload consolidation, a scheduling strategy, Sche-index, using the new index system for workload consolidation is proposed. Experiment results show that compared with traditional least-loaded scheduling strategy, Sche-index can improve both program performance and system resource utilization significantly.
基金supported by the National Natural Science Foundation of China(No.61475089)Development Projects of Shandong Province Science and Technology(No.2017GGX30102)
文摘A diode-pumped Tm:YLF passively Q-switched laser at 2μm was first demonstrated by using graphene oxide(GO)as a saturable absorber(SA).In this letter,continuous-wave(CW)laser and pulse laser performances were studied meticulously and systematically.It reasonably showed the dependence of the pulse duration,pulse energy,and pulse repetition rate on the absorbed power.A maximum repetition rate of 38.33 kHz and a single pulse energy of 9.89μJ were obtained.
基金supported by the National Natural Science Foundation of China under Grant Nos.61475089,61422511,61635012,and 51432007
文摘Using a novel silver nanorods absorber with a localized surface plasmon resonance absorption peak at 1.06μm,we obtain a diode-pumped passively Q-switched(PQS)Nd,Gd:CaF_(2) disordered crystal laser output.Its PQS pulse laser performances are studied comprehensively and systematically in this Letter.The single pulse energy and peak power can be attained to 2.15μJ and 2.06 W,respectively.
