We demonstrate a Kerr-lens mode-locked Yb:Lu YSiO_(5)(Yb:LYSO)laser with the pulse duration of 54 fs,corresponding to a spectral bandwidth of 25 nm centered at 1062 nm.To the best of our knowledge,this is the shortest...We demonstrate a Kerr-lens mode-locked Yb:Lu YSiO_(5)(Yb:LYSO)laser with the pulse duration of 54 fs,corresponding to a spectral bandwidth of 25 nm centered at 1062 nm.To the best of our knowledge,this is the shortest pulse duration obtained from Yb:LYSO laser.At the repetition rate of 378.3 MHz,an output power of 111.6 m W is obtained using an output coupler with 0.6%transmittance,which can maintain long-time stable mode-locking more than 13 h.展开更多
We demonstrate a diode-pumped passively cw mode-locked Nd：CaGdAlO4 laser operating at 1079nm with a semiconductor saturable absorber mirror for the first time to the best of our knowledge. The threshold pump power of...We demonstrate a diode-pumped passively cw mode-locked Nd：CaGdAlO4 laser operating at 1079nm with a semiconductor saturable absorber mirror for the first time to the best of our knowledge. The threshold pump power of the laser is 180mW. A maximum average output power of 93mW is obtained under the pump power of 1.94 W. The pulse duration of the mode-locked pulses is 3.1ps and the repetition rate is 157MHz.展开更多
We demonstrate a cw and actively Q-switched Er：LuAO laser resonantly dual-end-pumped by 1532nm fibre- coupled laser diodes. A maximum cw output power of 1.9W at 1650.3nm is obtained at a pump power of 25.5 W, corresp...We demonstrate a cw and actively Q-switched Er：LuAO laser resonantly dual-end-pumped by 1532nm fibre- coupled laser diodes. A maximum cw output power of 1.9W at 1650.3nm is obtained at a pump power of 25.5 W, corresponding to a slope efficiency of 43.3 %. In the Q-switched regime, the maximum pulse energy of 3.51 mJ is reached at a pulse repetition rate of 100 Hz, a pulse duration of 90.5ns and a pump power of 25.5 W. At the repetition rate of 400 Hz, the output energy is 2.12m J, corresponding to a pulse duration of 125.4 ns.展开更多
The 4-at.% Tm：Sc_2SiO_5 （Tm：SSO） crystal is successfully obtained by the Czochralski method. The optical properties and thermal conductivity of the crystal are investigated. The broad continuous wave（CW） laser o...The 4-at.% Tm：Sc_2SiO_5 （Tm：SSO） crystal is successfully obtained by the Czochralski method. The optical properties and thermal conductivity of the crystal are investigated. The broad continuous wave（CW） laser output of（100）-cut Tm：SSO with the dimensions of 3 mm×3 mm×3 mm under laser diode（LD）-pumping is realized. The full width at half maximum（FWHM） of the laser emitting reaches up to 21 nm. The laser threshold of Tm：SSO is measured to be 0.43 W. Efficient diode-pumped CW laser performance of Tm：SSO is demonstrated with a slope efficiency of 25.9% and maximum output power of 934 mW.展开更多
A diode-pumped actively Q-switched Raman laser is demonstrated, with YV04 employed as Raman active medium, based on a ceramic Nd：YAG laser operating at 1444nm. The first-stokes Raman generation at 1657nm is achieved....A diode-pumped actively Q-switched Raman laser is demonstrated, with YV04 employed as Raman active medium, based on a ceramic Nd：YAG laser operating at 1444nm. The first-stokes Raman generation at 1657nm is achieved. A maximum output power of as high as 612mW is obtained under a pump power of 20. 7 W and at a pulse repetition frequency rate of 20kHz, corresponding to an optical-to-optical conversion efficiency of 3%.展开更多
We demonstrate the temperature-dependent fluorescence properties of Pr：LiGdF4 crystal tor the first time, to the best of our knowledge, and its blue diode pumped cw red laser at 720 nm at room temperature. The fluore...We demonstrate the temperature-dependent fluorescence properties of Pr：LiGdF4 crystal tor the first time, to the best of our knowledge, and its blue diode pumped cw red laser at 720 nm at room temperature. The fluorescence lifetime and polarized emission cross sections in the visible range are measured and calculated in a temperature range from 77K to 300 K, and the variations of the fluorescence lifetime and spectra are discovered. The reasons for these changes are explained accordingly. The output wavelength of the 720nm laser is first reported on the laser performance by using a fiber-coupled laser diode at the wavelength of 442nm as the pump source, and the maximum cw output power is about 303roW.展开更多
Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized charact...Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized characteristics of mining slopes,this study introduces a new method that fuses model data from Unmanned aerial vehicles(UAV)tilt photogrammetry and 3D laser scanning through a data alignment algorithm based on control points.First,the mini batch K-Medoids algorithm is utilized to cluster the point cloud data from ground 3D laser scanning.Then,the elbow rule is applied to determine the optimal cluster number(K0),and the feature points are extracted.Next,the nearest neighbor point algorithm is employed to match the feature points obtained from UAV tilt photogrammetry,and the internal point coordinates are adjusted through the distanceweighted average to construct a 3D model.Finally,by integrating an engineering case study,the K0 value is determined to be 8,with a matching accuracy between the two model datasets ranging from 0.0669 to 1.0373 mm.Therefore,compared with the modeling method utilizing K-medoids clustering algorithm,the new modeling method significantly enhances the computational efficiency,the accuracy of selecting the optimal number of feature points in 3D laser scanning,and the precision of the 3D model derived from UAV tilt photogrammetry.This method provides a research foundation for constructing mine slope model.展开更多
A diode-pumped solid-state laser （DPSSL） with a high energetic stability and long service life is applied to ablate the steel samples instead of traditional Nd：YAG laser pumped by a xenon lamp, and several factors,...A diode-pumped solid-state laser （DPSSL） with a high energetic stability and long service life is applied to ablate the steel samples instead of traditional Nd：YAG laser pumped by a xenon lamp, and several factors, such as laser pulse energy, repetition rate and argon flow rate, that influence laser-induced breakdown spectroscopy （LIBS） analytical performance are investigated in detail. Under the optimal experiment conditions, the relative standard deviations for C, Si, Mn, Ni, Cr and Cu are 3.3%-8.9%, 0.9%-2.8%, 1.2%-4.1%, 1.7%-3.0%, 1.1%-3.4% and 2.5%-8.5%, respectively, with the corresponding relative errors of 1.1%-7.9%, 1.0%-6.3%, 0.4%-3.9%, 1.5%-6.3%, 1.2%-4.0% and 1.2%-6.4%. Compared with the results of the traditional spark discharge optical emission spectrometry technique, the analytical performance of LIBS is just a little inferior due to the less stable laser-induced plasma and smaller amount of ablated sample by the laser. However, the precision, detection limits and accuracy of LIBS obtained in our present work were sufficient to meet the requirements for process analysis. These technical performances of higher stability of output energy and longer service life for DPSSL, in comparison to the Q-switch laser pumped by xeon lamp, qualify it well for the real time online analysis for different industrial applications.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
This paper demonstrates the passively mode-locked Nd：GdVO4 laser operating on the ^4F3/2-^4I9/2 transition at 912 nm by using a semiconductor saturable-absorber mirror for passive mode locking, stable continuous wave...This paper demonstrates the passively mode-locked Nd：GdVO4 laser operating on the ^4F3/2-^4I9/2 transition at 912 nm by using a semiconductor saturable-absorber mirror for passive mode locking, stable continuous wave modelocked 912nm laser was achieved with a repetition rate of 176 MHz. At the incident pump power of 17.7W, 22.6mW average output power of stable mode-locked laser was obtained with a slope efficiency of 0.3%.展开更多
We report the specification of a compact and stable side diode-pumped Q-switched pulsed Nd：YAG laser. We ex- perimentally study and compare the performance of the pulsed Nd：YAG laser in the free-running and Q-switch...We report the specification of a compact and stable side diode-pumped Q-switched pulsed Nd：YAG laser. We ex- perimentally study and compare the performance of the pulsed Nd：YAG laser in the free-running and Q-switched modes at different pulse repetition rates from 1 Hz to 100 Hz. The laser output energy is stabilized by using a special configu- ration of the optical resonator. In this laser, an unsymmetrical concave-concave resonator is used and this structure helps the mode volume to be nearly fixed when the pulse repetition rate is increased. According to the experimental results in the Q-switched operation, the laser output energy is nearly constant around 70 mJ with an FWHM pulse width of 7 ns at 100 Hz. The optical-to-optical conversion efficiency in the Q-switched regime is 17.5%.展开更多
In this paper, we present a study of thermal, average power scaling, change in index of refraction and stress in photonic crystal fiber lasers with different pump schemes: forward pump scheme, backward pump scheme, fo...In this paper, we present a study of thermal, average power scaling, change in index of refraction and stress in photonic crystal fiber lasers with different pump schemes: forward pump scheme, backward pump scheme, forward pump scheme with reflection of 98%, backward pump scheme with reflection of 98% and bi-directional pump scheme. We show that management of thermal effects in fiber lasers will determine the efficiency and success of scaling-up efforts. In addition, we show that the most suitable scheme is the bi-directional.展开更多
An acoustic-optic Q-switched all-fiber laser With a high-repetition-rate, a short pulse width, a wide spectrum, and a high conversion efficiency is experimentally demonstrated. In the laser configuration, a （1＋1）x ...An acoustic-optic Q-switched all-fiber laser With a high-repetition-rate, a short pulse width, a wide spectrum, and a high conversion efficiency is experimentally demonstrated. In the laser configuration, a （1＋1）x 1 side-pumping coupler is introduced to perform backward pumping, and a 10/130%tm Yb fiber is adopted. The acoustic-optic component operates in the first direction, achieving a Q-switched pulse with a repetition rate adjustable in the range of 20 kHz-80 kHz. Under a repetition rate of 20 kHz and a pump power of 6.76 W, the fiber laser obtains a highly efficient and stable pulse output, with an average power of 4.3 W, a pulse width of 56 ns, a peak power of 3.83 kW, and a power density of 1.39x 101~ W/cm2. Particularly, the optic-optic conversion efficiency of the laser reaches as high as 64%. Another feature of the pulsed laser is that the high reflection mirror reflects the pump light as well, which brings the secondary absorption of the pump power into the gain fiber.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11774277 and 62105253)the Science and Technology Program of Xi’an(Grant No.202005YK01)+2 种基金the Natural Science Basic Research Program of Shaanxi,China(Grant No.2019JCW-03)the Natural Science Foundation of Shannxi Province,China(Grant Nos.2022JQ-709 and 2023-JC-YB-485)the Fundamental Research Funds for the Central Universities(Grant No.XJS222206)。
文摘We demonstrate a Kerr-lens mode-locked Yb:Lu YSiO_(5)(Yb:LYSO)laser with the pulse duration of 54 fs,corresponding to a spectral bandwidth of 25 nm centered at 1062 nm.To the best of our knowledge,this is the shortest pulse duration obtained from Yb:LYSO laser.At the repetition rate of 378.3 MHz,an output power of 111.6 m W is obtained using an output coupler with 0.6%transmittance,which can maintain long-time stable mode-locking more than 13 h.
基金Supported by the National Key Basic Research Program of China under Grant No 2013CB922402the International Joint Research Program of the National Natural Science Foundation of China under Grant No 61210017
文摘We demonstrate a diode-pumped passively cw mode-locked Nd：CaGdAlO4 laser operating at 1079nm with a semiconductor saturable absorber mirror for the first time to the best of our knowledge. The threshold pump power of the laser is 180mW. A maximum average output power of 93mW is obtained under the pump power of 1.94 W. The pulse duration of the mode-locked pulses is 3.1ps and the repetition rate is 157MHz.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61308009 and 61405047the China Postdoctoral Science Foundation Funded Project under Grant No 2013M540288+2 种基金the Fundamental Research Funds for the Central Universities under Grant Nos HIT.NSRIF.2014044 and HIT.NSRIF.2015042the Science Fund for Outstanding Youths of Heilongjiang Province under Grant No JQ201310the Heilongjiang Postdoctoral Science Foundation Funded Project under Grant No LBH-Z14085
文摘We demonstrate a cw and actively Q-switched Er：LuAO laser resonantly dual-end-pumped by 1532nm fibre- coupled laser diodes. A maximum cw output power of 1.9W at 1650.3nm is obtained at a pump power of 25.5 W, corresponding to a slope efficiency of 43.3 %. In the Q-switched regime, the maximum pulse energy of 3.51 mJ is reached at a pulse repetition rate of 100 Hz, a pulse duration of 90.5ns and a pump power of 25.5 W. At the repetition rate of 400 Hz, the output energy is 2.12m J, corresponding to a pulse duration of 125.4 ns.
基金supported by the Shanghai Municipal Engineering Research Center for Sapphire Crystals,China(Grant No.14DZ2252500)the Fund of Key Laboratory of Optoelectronic Materials Chemistry and Physics,Chinese Academy of Sciences(Grant No.2008DP17301)+4 种基金the Fundamental Research Funds for the Central Universitiesthe National Natural Science Foundation of China and the China Academy of Engineering Physics Joint Fund(Grant No.U1530152)the National Natural Science Foundation of China(Grant Nos.61475177 and 61621001)the Shanghai Municipal Natural Science Foundation,China(Grant No.13ZR1446100)the MDE Key Laboratory of Advanced Micro-Structured Materials
文摘The 4-at.% Tm：Sc_2SiO_5 （Tm：SSO） crystal is successfully obtained by the Czochralski method. The optical properties and thermal conductivity of the crystal are investigated. The broad continuous wave（CW） laser output of（100）-cut Tm：SSO with the dimensions of 3 mm×3 mm×3 mm under laser diode（LD）-pumping is realized. The full width at half maximum（FWHM） of the laser emitting reaches up to 21 nm. The laser threshold of Tm：SSO is measured to be 0.43 W. Efficient diode-pumped CW laser performance of Tm：SSO is demonstrated with a slope efficiency of 25.9% and maximum output power of 934 mW.
基金Supported by the Foundation of the State Key Laboratory of Crystal Material of Shandong University under Grant No KF1101the Foundation of Shandong University under Grant No 1170072613176+2 种基金the National Natural Science Foundation of China under Grant Nos 11004122 and 11204160the Special Grade of China Postdoctoral Science Foundation under Grant No 201104627the Independent Innovation Foundation of Shandong University under Grant No 2011GN058
文摘A diode-pumped actively Q-switched Raman laser is demonstrated, with YV04 employed as Raman active medium, based on a ceramic Nd：YAG laser operating at 1444nm. The first-stokes Raman generation at 1657nm is achieved. A maximum output power of as high as 612mW is obtained under a pump power of 20. 7 W and at a pulse repetition frequency rate of 20kHz, corresponding to an optical-to-optical conversion efficiency of 3%.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51025210,51102156 and 51272131the Young and Middle-Aged Scientists Research Awards Fund of Shandong Province under Grant No BS2011CL024
文摘We demonstrate the temperature-dependent fluorescence properties of Pr：LiGdF4 crystal tor the first time, to the best of our knowledge, and its blue diode pumped cw red laser at 720 nm at room temperature. The fluorescence lifetime and polarized emission cross sections in the visible range are measured and calculated in a temperature range from 77K to 300 K, and the variations of the fluorescence lifetime and spectra are discovered. The reasons for these changes are explained accordingly. The output wavelength of the 720nm laser is first reported on the laser performance by using a fiber-coupled laser diode at the wavelength of 442nm as the pump source, and the maximum cw output power is about 303roW.
基金funded by National Natural Science Foundation of China(Grant Nos.42272333,42277147).
文摘Refined 3D modeling of mine slopes is pivotal for precise prediction of geological hazards.Aiming at the inadequacy of existing single modeling methods in comprehensively representing the overall and localized characteristics of mining slopes,this study introduces a new method that fuses model data from Unmanned aerial vehicles(UAV)tilt photogrammetry and 3D laser scanning through a data alignment algorithm based on control points.First,the mini batch K-Medoids algorithm is utilized to cluster the point cloud data from ground 3D laser scanning.Then,the elbow rule is applied to determine the optimal cluster number(K0),and the feature points are extracted.Next,the nearest neighbor point algorithm is employed to match the feature points obtained from UAV tilt photogrammetry,and the internal point coordinates are adjusted through the distanceweighted average to construct a 3D model.Finally,by integrating an engineering case study,the K0 value is determined to be 8,with a matching accuracy between the two model datasets ranging from 0.0669 to 1.0373 mm.Therefore,compared with the modeling method utilizing K-medoids clustering algorithm,the new modeling method significantly enhances the computational efficiency,the accuracy of selecting the optimal number of feature points in 3D laser scanning,and the precision of the 3D model derived from UAV tilt photogrammetry.This method provides a research foundation for constructing mine slope model.
基金supported by the Development Fund of National Autonomous Demonstration Innovation Zone of Shandong Peninsula(Grant No.ZCQ17104)the National Key Research and Development Program of China(Grant No.2017YFB0305400)‘double hundred plan’ Yantai talent funding project
文摘A diode-pumped solid-state laser （DPSSL） with a high energetic stability and long service life is applied to ablate the steel samples instead of traditional Nd：YAG laser pumped by a xenon lamp, and several factors, such as laser pulse energy, repetition rate and argon flow rate, that influence laser-induced breakdown spectroscopy （LIBS） analytical performance are investigated in detail. Under the optimal experiment conditions, the relative standard deviations for C, Si, Mn, Ni, Cr and Cu are 3.3%-8.9%, 0.9%-2.8%, 1.2%-4.1%, 1.7%-3.0%, 1.1%-3.4% and 2.5%-8.5%, respectively, with the corresponding relative errors of 1.1%-7.9%, 1.0%-6.3%, 0.4%-3.9%, 1.5%-6.3%, 1.2%-4.0% and 1.2%-6.4%. Compared with the results of the traditional spark discharge optical emission spectrometry technique, the analytical performance of LIBS is just a little inferior due to the less stable laser-induced plasma and smaller amount of ablated sample by the laser. However, the precision, detection limits and accuracy of LIBS obtained in our present work were sufficient to meet the requirements for process analysis. These technical performances of higher stability of output energy and longer service life for DPSSL, in comparison to the Q-switch laser pumped by xeon lamp, qualify it well for the real time online analysis for different industrial applications.
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 60225005, 60308001, 60321003 and 60490280）.
文摘This paper demonstrates the passively mode-locked Nd：GdVO4 laser operating on the ^4F3/2-^4I9/2 transition at 912 nm by using a semiconductor saturable-absorber mirror for passive mode locking, stable continuous wave modelocked 912nm laser was achieved with a repetition rate of 176 MHz. At the incident pump power of 17.7W, 22.6mW average output power of stable mode-locked laser was obtained with a slope efficiency of 0.3%.
文摘We report the specification of a compact and stable side diode-pumped Q-switched pulsed Nd：YAG laser. We ex- perimentally study and compare the performance of the pulsed Nd：YAG laser in the free-running and Q-switched modes at different pulse repetition rates from 1 Hz to 100 Hz. The laser output energy is stabilized by using a special configu- ration of the optical resonator. In this laser, an unsymmetrical concave-concave resonator is used and this structure helps the mode volume to be nearly fixed when the pulse repetition rate is increased. According to the experimental results in the Q-switched operation, the laser output energy is nearly constant around 70 mJ with an FWHM pulse width of 7 ns at 100 Hz. The optical-to-optical conversion efficiency in the Q-switched regime is 17.5%.
文摘In this paper, we present a study of thermal, average power scaling, change in index of refraction and stress in photonic crystal fiber lasers with different pump schemes: forward pump scheme, backward pump scheme, forward pump scheme with reflection of 98%, backward pump scheme with reflection of 98% and bi-directional pump scheme. We show that management of thermal effects in fiber lasers will determine the efficiency and success of scaling-up efforts. In addition, we show that the most suitable scheme is the bi-directional.
基金supported by the National Natural Science Foundation of China(Grant No.61307057)the State Key Laboratory of Tribology,Tsinghua University,China(Grant No.SKLT12B08)China Postdoctoral Science Foundation(Grant Nos.2012M520258 and 2013T60109)
文摘An acoustic-optic Q-switched all-fiber laser With a high-repetition-rate, a short pulse width, a wide spectrum, and a high conversion efficiency is experimentally demonstrated. In the laser configuration, a （1＋1）x 1 side-pumping coupler is introduced to perform backward pumping, and a 10/130%tm Yb fiber is adopted. The acoustic-optic component operates in the first direction, achieving a Q-switched pulse with a repetition rate adjustable in the range of 20 kHz-80 kHz. Under a repetition rate of 20 kHz and a pump power of 6.76 W, the fiber laser obtains a highly efficient and stable pulse output, with an average power of 4.3 W, a pulse width of 56 ns, a peak power of 3.83 kW, and a power density of 1.39x 101~ W/cm2. Particularly, the optic-optic conversion efficiency of the laser reaches as high as 64%. Another feature of the pulsed laser is that the high reflection mirror reflects the pump light as well, which brings the secondary absorption of the pump power into the gain fiber.
