Ag/AgBr/GdVO_4 composite photocatalysts were designed and synthesized in this paper.The physical and chemical structures, as well as optical properties of the synthesized composite were investigated via XRD, XPS, TEM,...Ag/AgBr/GdVO_4 composite photocatalysts were designed and synthesized in this paper.The physical and chemical structures, as well as optical properties of the synthesized composite were investigated via XRD, XPS, TEM, and UV–vis. It is found that the composite showed a ternary heterojunction structure of Ag, Ag Br and GdVO_4. Meanwhile, it has a high intensity of light current, indicating its high separation efficiency of electron and hole.Photocatalytic oxidation of rhodamine B（RhB） under visible light irradiation was performed to investigate the activity of the Ag/Ag Br/GdVO_4 composite. Result indicates that it shows excellent photocatalytic activity. Under visible light irradiation for 12 min, about 80% of Rh B（30 μmol/L） was degraded. The degradation rate is estimated to be 0.253 min1, which is three times higher than that of pure AgBr. The high photoactivity can be ascribed to the synergetic effect of Ag Br, GdVO_4, and Ag nanoparticle in separation of electron–hole pairs.展开更多
Objective:The properties of Nd:GdVO4 laser crystals were studied in application of all-solid laser with LD pumped.Method:We adopted sand wich structural Nd:YVO4 laser crystals experimental devices separately.Results:...Objective:The properties of Nd:GdVO4 laser crystals were studied in application of all-solid laser with LD pumped.Method:We adopted sand wich structural Nd:YVO4 laser crystals experimental devices separately.Results:As to Nd:YVO4 crystal,1.2W continuous laser output at 1064nm was ac-quired with the optical-to-optical transition efficiency of 30%.And as to Nd:GdVO4,1.8W continuous laser out-put at 1064nm was acquired with the optical-to-optical efficiency of 47.2%.Conclusion:All-solid laser is of simple and compact structure,long lifetime,low cost and high efficiency that it will be extensively applied to laser bioengineering,laser environmental monitoring and so on.And comparing the properties of Nd:GdVO4 to that of Nd:YVO4,Nd:GdVO4 would be a more promising all-solid laser crystal.展开更多
Ho^3＋ ： GdVO4 is a new laser material suitable for high-power laser systems. In this paper we measure the absorption spectra of Ho^3＋ in the sample Ho^3＋： GdVO4. The intensity parameters are calculated by using t...Ho^3＋ ： GdVO4 is a new laser material suitable for high-power laser systems. In this paper we measure the absorption spectra of Ho^3＋ in the sample Ho^3＋： GdVO4. The intensity parameters are calculated by using the Judd-Ofelt theory. Some predicted spectroscopic parameters, such as the spontaneous radiative transition rate, branching ratio and integrated emission cross section are dealt with. And we also compare the optical parameters with those of other materials. From these results, it is found that there are many transitions which have large oscillator strengths and large integrated emission cross sections. Especially the transitions such as ^5 F4 → ^5 I 8, ^5 S2→^5 I8, ^5 F5 → ^5 I8 and ^5 I7 →^ 5 I8 are useful in solid-state lasers and other fields. Finally, we discuss the splitting of the energy levels of Ho^3＋ in the crystal GdVO4 based on the group theory.展开更多
The passively Q-switched and mode-locked（QML） characteristics in a diode-pumped Nd∶GdVO4 laser with Cr4+∶YAG saturable absorbers have been demonstrated. A maximum average output power of 710mW has been obtained in...The passively Q-switched and mode-locked（QML） characteristics in a diode-pumped Nd∶GdVO4 laser with Cr4+∶YAG saturable absorbers have been demonstrated. A maximum average output power of 710mW has been obtained in the QML laser. The maximum energy of a single Q-switched pulse is 52.5μJ, with the corresponding pulse width of 30ns and the peak power of 1.75kW, at the incident pump power of 7.75W. The repetition rates of the Q-switched envelope and the mode-locked laser pulse are 16.7kHz and 680MHz, respectively.展开更多
基金supported by the Natural Science Foundation of Zhejiang Province (No. LY14B030002)National Undergraduate Training Program for Innovation and Entrepreneurship (No. 201610345016)
文摘Ag/AgBr/GdVO_4 composite photocatalysts were designed and synthesized in this paper.The physical and chemical structures, as well as optical properties of the synthesized composite were investigated via XRD, XPS, TEM, and UV–vis. It is found that the composite showed a ternary heterojunction structure of Ag, Ag Br and GdVO_4. Meanwhile, it has a high intensity of light current, indicating its high separation efficiency of electron and hole.Photocatalytic oxidation of rhodamine B（RhB） under visible light irradiation was performed to investigate the activity of the Ag/Ag Br/GdVO_4 composite. Result indicates that it shows excellent photocatalytic activity. Under visible light irradiation for 12 min, about 80% of Rh B（30 μmol/L） was degraded. The degradation rate is estimated to be 0.253 min1, which is three times higher than that of pure AgBr. The high photoactivity can be ascribed to the synergetic effect of Ag Br, GdVO_4, and Ag nanoparticle in separation of electron–hole pairs.
文摘Objective:The properties of Nd:GdVO4 laser crystals were studied in application of all-solid laser with LD pumped.Method:We adopted sand wich structural Nd:YVO4 laser crystals experimental devices separately.Results:As to Nd:YVO4 crystal,1.2W continuous laser output at 1064nm was ac-quired with the optical-to-optical transition efficiency of 30%.And as to Nd:GdVO4,1.8W continuous laser out-put at 1064nm was acquired with the optical-to-optical efficiency of 47.2%.Conclusion:All-solid laser is of simple and compact structure,long lifetime,low cost and high efficiency that it will be extensively applied to laser bioengineering,laser environmental monitoring and so on.And comparing the properties of Nd:GdVO4 to that of Nd:YVO4,Nd:GdVO4 would be a more promising all-solid laser crystal.
基金Project supported by the National Natural Science Foundation of China (Grant No 10174008)
文摘Ho^3＋ ： GdVO4 is a new laser material suitable for high-power laser systems. In this paper we measure the absorption spectra of Ho^3＋ in the sample Ho^3＋： GdVO4. The intensity parameters are calculated by using the Judd-Ofelt theory. Some predicted spectroscopic parameters, such as the spontaneous radiative transition rate, branching ratio and integrated emission cross section are dealt with. And we also compare the optical parameters with those of other materials. From these results, it is found that there are many transitions which have large oscillator strengths and large integrated emission cross sections. Especially the transitions such as ^5 F4 → ^5 I 8, ^5 S2→^5 I8, ^5 F5 → ^5 I8 and ^5 I7 →^ 5 I8 are useful in solid-state lasers and other fields. Finally, we discuss the splitting of the energy levels of Ho^3＋ in the crystal GdVO4 based on the group theory.
文摘The passively Q-switched and mode-locked（QML） characteristics in a diode-pumped Nd∶GdVO4 laser with Cr4+∶YAG saturable absorbers have been demonstrated. A maximum average output power of 710mW has been obtained in the QML laser. The maximum energy of a single Q-switched pulse is 52.5μJ, with the corresponding pulse width of 30ns and the peak power of 1.75kW, at the incident pump power of 7.75W. The repetition rates of the Q-switched envelope and the mode-locked laser pulse are 16.7kHz and 680MHz, respectively.
