Laser conditioning is an effective method to improve the laser damage threshold of HfO2/SiO2 multilayer films prepared by electron beam evaporation. In this paper, some parameters that can affect the efficiency of las...Laser conditioning is an effective method to improve the laser damage threshold of HfO2/SiO2 multilayer films prepared by electron beam evaporation. In this paper, some parameters that can affect the efficiency of laser conditioning were discussed. The result is that the maximum conditioning fluence should be less than 90% of its unconditioned laser induced damage threshold (LIDT) to avoid damage to the film. The laser beam increment between pulses and laser conditioning steps has a great influence on the improvement of damage threshold of HfO2/SiO2 multilayer high reflective coatings. The coverage of the light intensity on the defect should be as wide as possible, and the irradiation of light intensity should be as high as possible. The main mechanisms of laser conditioning of HfO2/SiO2 multilayer high reflective coatings may be the removal of Hf, Si and O ions and the removal of the defects in the films.展开更多
A series of (SrNa)2-xEux(MoO4)3 red phosphors have been synthesized by using the sol-gel method. X-ray diffraction, used to characterize the crystallization process of the phosphor precursors, indicates that the (SrNa...A series of (SrNa)2-xEux(MoO4)3 red phosphors have been synthesized by using the sol-gel method. X-ray diffraction, used to characterize the crystallization process of the phosphor precursors, indicates that the (SrNa)2-xEux(MoO4)3 phosphors had an SrMoO4 structure. The properties of these resulting phosphors have also been characterized by using photoluminescence (PL) spectra. The PL results indicate that all of the (SrNa)2-xEux(MoO4)3 phosphors exhibit intense red emissions under 275, 395, and 465-nm excitation. The two strongest lines at 395 and 465 nm in the excitation spectra of these phosphors match well with the two popular emissions from near-UV and blue GaN-based light-emitting diodes. Some process parameters for Eu3+ concentration, (C6H8O7)·H2O concentration, and solution pH value were also investigated. For (SrNa)2-xEux(MoO4)3 phosphors, there are two maximum emission intensities appearing with x = 0.6 and x = 1.4, respectively. When the molar ratio of citric acid is equal to that of metal cations and the solution pH is almost 4, (SrNa)2-xEux(MoO4)3 shows the strongest emission intensity compared to those under other conditions.展开更多
文摘Laser conditioning is an effective method to improve the laser damage threshold of HfO2/SiO2 multilayer films prepared by electron beam evaporation. In this paper, some parameters that can affect the efficiency of laser conditioning were discussed. The result is that the maximum conditioning fluence should be less than 90% of its unconditioned laser induced damage threshold (LIDT) to avoid damage to the film. The laser beam increment between pulses and laser conditioning steps has a great influence on the improvement of damage threshold of HfO2/SiO2 multilayer high reflective coatings. The coverage of the light intensity on the defect should be as wide as possible, and the irradiation of light intensity should be as high as possible. The main mechanisms of laser conditioning of HfO2/SiO2 multilayer high reflective coatings may be the removal of Hf, Si and O ions and the removal of the defects in the films.
文摘A series of (SrNa)2-xEux(MoO4)3 red phosphors have been synthesized by using the sol-gel method. X-ray diffraction, used to characterize the crystallization process of the phosphor precursors, indicates that the (SrNa)2-xEux(MoO4)3 phosphors had an SrMoO4 structure. The properties of these resulting phosphors have also been characterized by using photoluminescence (PL) spectra. The PL results indicate that all of the (SrNa)2-xEux(MoO4)3 phosphors exhibit intense red emissions under 275, 395, and 465-nm excitation. The two strongest lines at 395 and 465 nm in the excitation spectra of these phosphors match well with the two popular emissions from near-UV and blue GaN-based light-emitting diodes. Some process parameters for Eu3+ concentration, (C6H8O7)·H2O concentration, and solution pH value were also investigated. For (SrNa)2-xEux(MoO4)3 phosphors, there are two maximum emission intensities appearing with x = 0.6 and x = 1.4, respectively. When the molar ratio of citric acid is equal to that of metal cations and the solution pH is almost 4, (SrNa)2-xEux(MoO4)3 shows the strongest emission intensity compared to those under other conditions.
