In this paper, the spectral and luminescence properties of a series of KGd（WO4）2 powder samples codoped with different concentrations of Er^3＋ and Yb^3＋ were reported,and the best doping concentrations were found ...In this paper, the spectral and luminescence properties of a series of KGd（WO4）2 powder samples codoped with different concentrations of Er^3＋ and Yb^3＋ were reported,and the best doping concentrations were found to be lat% Er^3＋ and 10at% Yb^3＋ for attaining the strongest intensity. The Er^3＋/yb^3＋ codoped KGd（WO4）2 crystal with good optical quality was grown by the TSSG method and the growth conditions were presented. The unpolarized absorption and emission spectra of the crystal have been measured. The strong absorption peak is at 980 nm with a FWHM of 65 nm, and the emission peak is at 1536 nm when pumped by 976 rim. The fluorescence lifetime of manifold ^4I13/2 is estimated to be 4.5 ms at room temperature.Investigations of Er, Yb：KGW crystal have shown it to have necessary combination of properties to get an effective generation of - 1.54 μm eye-safe radiation with laser diode pumping.展开更多
The Nd^3＋ 3.2% （atom fraction）：KGd（WO4）2 crystal was grown by Kyropoulos method. The absorption spectrum and fluorescence spectrum of Nd^3 ＋ ： KGW crystal were measured. The absorption cross sections at 808 nm...The Nd^3＋ 3.2% （atom fraction）：KGd（WO4）2 crystal was grown by Kyropoulos method. The absorption spectrum and fluorescence spectrum of Nd^3 ＋ ： KGW crystal were measured. The absorption cross sections at 808 nm（0. 6799 × 10^-20 cm^2） were calculated, and the output wavelength of fluorescence is 1064 and 1351 nm. The diode-pumped laser was operated both in the free-running and passively Q-switched operating modes. The maximum laser output（1064 nm） is 326 mW with 62.7 % slope efficiency when input energy is 900 mW. The beam quality factor M^2 ≈ 1.1. The green light of 532 nm is obtained in frequency doubling operation. The laser is passively Q-switched by using Cr^4＋ ：LuAG as saturable absorber. The pulse width is 170 ns at repetitive frequency of 15 kHZ.展开更多
In recent years,from the laser experimental study of neodymium doped potassium g adolinium tungstate,i.e.KGd(WO 4) 2 (KGW),laser scientific workers had discove r ed that it has many advantages,as compared to YAG and o...In recent years,from the laser experimental study of neodymium doped potassium g adolinium tungstate,i.e.KGd(WO 4) 2 (KGW),laser scientific workers had discove r ed that it has many advantages,as compared to YAG and other tungstate crystals u n der indentical experimental conditions,such as low lasing threshold,high output energy o r power and high efficiency et al.Especially,as seen on the absorption spectra o f Nd:YAG and Nd:KGW reported by V.Kushawaha et al,a strong and broad absorption line around 808nm is much wider (～12nmFWHM) in Nd:KGW as compared to the Nd:YAG (～1.5nm FWHM),and this wavelength is just during the main peak area emitted by diode laser,so that Nd:KGW may be a excellent candidate for efficient diode pum ping at 808nm.Therefore the research and development of KGW crystals and laser d evices has been bestowed great attention in interational laser science area.For the laser rod with dimensions of 5mm×8mm and 6.3mm×75mm,the xenon flashlamp pumping KGW laser have achieved more laser output and higher efficie n ies than the YAG crystals under identical experimental conditions,by V.Kushawaha et al.In Unite State and K.A.Stankov et al.in Germang respectively.展开更多
We demonstrate a continuous-wave(CW)Nd:YVO_(4)-potassium gadolinium tungstate(KGW)intracavity Raman laser with a diode-to-Stokes optical efficiency of 34.2%.By optimizing the cavity arrangement and reducing the cavity...We demonstrate a continuous-wave(CW)Nd:YVO_(4)-potassium gadolinium tungstate(KGW)intracavity Raman laser with a diode-to-Stokes optical efficiency of 34.2%.By optimizing the cavity arrangement and reducing the cavity losses,8.47 W Stokes output at 1177 nm was obtained under an incident 878.6 nm diode pump power of 24.8 W.The influence of cavity losses on the power and efficiency of the CW Raman laser,as well as the potential for further optimization,was investigated based on the numerical model.The observation of thermally-induced output rollover was well explained by the calculation of the thermal lensing and cavity stability,indicating that the end-face curvature played an important role when the end-face of the crystal was highly reflective coated to make the cavity.A 10.9 W Stokes output under 40.9 W incident pump was also demonstrated with a cavity arrangement less sensitive to the end-face curvature,which is the highest output power of CW intracavity Raman lasers reported.展开更多
We report on a high-power diode-pumped Yb∶KG(WO_(4))_(2)(Yb:KGW) mode-locked laser with a semiconductor saturable absorber mirror(SESAM). For 32.7 W of incident pump power, we generate 261 fs pulses with the maximum ...We report on a high-power diode-pumped Yb∶KG(WO_(4))_(2)(Yb:KGW) mode-locked laser with a semiconductor saturable absorber mirror(SESAM). For 32.7 W of incident pump power, we generate 261 fs pulses with the maximum average output power of up to 13.0 W and spectrum centered around 1039 nm at 68.4 MHz, corresponding to 190 n J of single pulse energy and0.72 MW of peak power. The optical-to-optical conversion efficiency is 39.8%, and the slope efficiency is 64.4%. The Yb:KGW laser exhibits a power stability better than 0.543% of the root-mean-square in 2 h.展开更多
基金This project was supported by the Natural Science Foundation of Fujian Province (No. E0310031) ② Corresponding author. E-mail: tcy@fjirsm.ac.cn
文摘In this paper, the spectral and luminescence properties of a series of KGd（WO4）2 powder samples codoped with different concentrations of Er^3＋ and Yb^3＋ were reported,and the best doping concentrations were found to be lat% Er^3＋ and 10at% Yb^3＋ for attaining the strongest intensity. The Er^3＋/yb^3＋ codoped KGd（WO4）2 crystal with good optical quality was grown by the TSSG method and the growth conditions were presented. The unpolarized absorption and emission spectra of the crystal have been measured. The strong absorption peak is at 980 nm with a FWHM of 65 nm, and the emission peak is at 1536 nm when pumped by 976 rim. The fluorescence lifetime of manifold ^4I13/2 is estimated to be 4.5 ms at room temperature.Investigations of Er, Yb：KGW crystal have shown it to have necessary combination of properties to get an effective generation of - 1.54 μm eye-safe radiation with laser diode pumping.
文摘The Nd^3＋ 3.2% （atom fraction）：KGd（WO4）2 crystal was grown by Kyropoulos method. The absorption spectrum and fluorescence spectrum of Nd^3 ＋ ： KGW crystal were measured. The absorption cross sections at 808 nm（0. 6799 × 10^-20 cm^2） were calculated, and the output wavelength of fluorescence is 1064 and 1351 nm. The diode-pumped laser was operated both in the free-running and passively Q-switched operating modes. The maximum laser output（1064 nm） is 326 mW with 62.7 % slope efficiency when input energy is 900 mW. The beam quality factor M^2 ≈ 1.1. The green light of 532 nm is obtained in frequency doubling operation. The laser is passively Q-switched by using Cr^4＋ ：LuAG as saturable absorber. The pulse width is 170 ns at repetitive frequency of 15 kHZ.
文摘In recent years,from the laser experimental study of neodymium doped potassium g adolinium tungstate,i.e.KGd(WO 4) 2 (KGW),laser scientific workers had discove r ed that it has many advantages,as compared to YAG and other tungstate crystals u n der indentical experimental conditions,such as low lasing threshold,high output energy o r power and high efficiency et al.Especially,as seen on the absorption spectra o f Nd:YAG and Nd:KGW reported by V.Kushawaha et al,a strong and broad absorption line around 808nm is much wider (～12nmFWHM) in Nd:KGW as compared to the Nd:YAG (～1.5nm FWHM),and this wavelength is just during the main peak area emitted by diode laser,so that Nd:KGW may be a excellent candidate for efficient diode pum ping at 808nm.Therefore the research and development of KGW crystals and laser d evices has been bestowed great attention in interational laser science area.For the laser rod with dimensions of 5mm×8mm and 6.3mm×75mm,the xenon flashlamp pumping KGW laser have achieved more laser output and higher efficie n ies than the YAG crystals under identical experimental conditions,by V.Kushawaha et al.In Unite State and K.A.Stankov et al.in Germang respectively.
基金This work was supported by the National Natural Science Foundation of China(Nos.61975146,62105240,62075159,and 62275190)the Shandong Province Key R&D Program(Nos.2020CXGC010104 and 2021CXGC010202)the Seed Foundation of Tianjin University(No.2023XPD-0020).
文摘We demonstrate a continuous-wave(CW)Nd:YVO_(4)-potassium gadolinium tungstate(KGW)intracavity Raman laser with a diode-to-Stokes optical efficiency of 34.2%.By optimizing the cavity arrangement and reducing the cavity losses,8.47 W Stokes output at 1177 nm was obtained under an incident 878.6 nm diode pump power of 24.8 W.The influence of cavity losses on the power and efficiency of the CW Raman laser,as well as the potential for further optimization,was investigated based on the numerical model.The observation of thermally-induced output rollover was well explained by the calculation of the thermal lensing and cavity stability,indicating that the end-face curvature played an important role when the end-face of the crystal was highly reflective coated to make the cavity.A 10.9 W Stokes output under 40.9 W incident pump was also demonstrated with a cavity arrangement less sensitive to the end-face curvature,which is the highest output power of CW intracavity Raman lasers reported.
文摘基于对LD端面泵浦Yb∶KGW激光晶体工作特点的分析,建立了符合条件的激光晶体热模型.考虑晶体侧面的热对流,运用MATLAB和FORTRAN软件,通过有限差分法求解各向异性介质热传导方程,得到了该晶体的温度场分布、端面热形变分布和不同泵浦功率下的热焦距.结果表明:在泵浦功率为14 W时,泵浦面最高温度达272.8℃、最大形变为0.48μm,光斑附近的热焦距为4.8 cm.
基金This work was supported by the National Natural Science Foundation of China(No.11774410)Strategic Priority Research Program of CAS(No.XDB16030200)。
文摘We report on a high-power diode-pumped Yb∶KG(WO_(4))_(2)(Yb:KGW) mode-locked laser with a semiconductor saturable absorber mirror(SESAM). For 32.7 W of incident pump power, we generate 261 fs pulses with the maximum average output power of up to 13.0 W and spectrum centered around 1039 nm at 68.4 MHz, corresponding to 190 n J of single pulse energy and0.72 MW of peak power. The optical-to-optical conversion efficiency is 39.8%, and the slope efficiency is 64.4%. The Yb:KGW laser exhibits a power stability better than 0.543% of the root-mean-square in 2 h.
