We report novel results on top-down percussion drilling in different glasses with femtosecond laser GHz-bursts.Thanks to this particular regime of light–matter interaction,combining non-linear absorption and thermal ...We report novel results on top-down percussion drilling in different glasses with femtosecond laser GHz-bursts.Thanks to this particular regime of light–matter interaction,combining non-linear absorption and thermal cumulative effects,we obtained crack-free holes of aspect ratios exceeding 30 in sodalime and 70 in fused silica.The results are discussed in terms of inner wall morphology,aspect ratio and drilling speed.展开更多
BACKGROUND This case of gestational gingival tumor is huge and extremely rare in clinical practice.As the growth location of this gingival tumor is in the upper anterior tooth area,it seriously affects the pregnant wo...BACKGROUND This case of gestational gingival tumor is huge and extremely rare in clinical practice.As the growth location of this gingival tumor is in the upper anterior tooth area,it seriously affects the pregnant woman's speech and food,causing great pain to the patient.The use of Nd:YGA water mist laser to remove the gingival tumor resulted in minimal intraoperative bleeding,minimal adverse reactions,and good postoperative healing,which is worthy of clinical promotion and application.CASE SUMMARY The patient,a pregnant woman,reported a large lump in her mouth on the first day of postpartum treatment.Based on medical history and clinical examination,the diagnosis was diagnosed as gestational gingival tumor.Postoperative pathological biopsy also confirmed this diagnosis.The use of Nd:YAG water mist laser to remove the tumor resulted in minimal intraoperative bleeding,clear surgical field of view,short surgical time,and good postoperative healing.CONCLUSION In comparison to traditional surgery,Nd:YAG water mist laser surgery is minimally invasive,minimizes cell damage,reduces bleeding,ensures a clear field of vision,and virtually eliminates postoperative edema,carbonization,and the risk of cross infection.It has unique advantages in oral soft tissue surgery for pregnant patients.Therefore,the clinical application of Nd:YAG water mist laser for the treatment of gestational gingival tumors is an ideal choice.展开更多
The effects of femtosecond laser ablation on the surface characteristics and microstructure of a bulk TiCuPdZr glass alloy were investigated. The heat influence zone of femtosecond laser ablated with a laser energy of...The effects of femtosecond laser ablation on the surface characteristics and microstructure of a bulk TiCuPdZr glass alloy were investigated. The heat influence zone of femtosecond laser ablated with a laser energy of 100 μJ exhibits a ripple-like feather, while a porous structure appears on the surface of the specimen ablated by a 200 μJ femtosecond laser. The contents of Ti, Zr, and Pd on the ablated surface decrease and that of Cu increases with increasing laser energy. The crystallization process occurs on the glass alloy specimens during femtosecond laser ablation, and the crystallinity of a 100 μJ femtosecond laser-ablated specimen is greater than that of a 200 μJ femtosecond laser-ablated one.展开更多
The Yb3^+ -doped silicate, phosphate and borophosphate laser glasses were prepared by means of conventional melt quenching technology. The physical and spectral properties of the glasses were investigated. The result...The Yb3^+ -doped silicate, phosphate and borophosphate laser glasses were prepared by means of conventional melt quenching technology. The physical and spectral properties of the glasses were investigated. The results show that, due to the existence of OH^-, the fluorescence lifetime of phosphate glass is shorter than that of silicate glass, so silicate glass has better spectral properties than phosphate glass. Silicate glass has better mechanical and thermal properties than phosphate glass, but with the addition of B2O3, mechanical and thermal properties of phosphate glass are improved greatly without fluorescence quenching effect. This kind of borophosphate glass can be used in high average power solid state lasers.展开更多
The details of the special three-dimensional micro-nano scale ripples with a period of hundreds of microns on the surfaces of a Zr-based and a La-based metallic glass irradiated separately by single laser pulse are in...The details of the special three-dimensional micro-nano scale ripples with a period of hundreds of microns on the surfaces of a Zr-based and a La-based metallic glass irradiated separately by single laser pulse are investigated.We use the small-amplitude capillary wave theory to unveil the ripple formation mechanism through considering each of the molten metallic glasses as an incompressible viscous fluid.A generalized model is presented to describe the special morphology,which fits the experimental result well.It is also revealed that the viscosity brings about the biggest effect on the monotone decreasing nature of the amplitude and the wavelength of the surface ripples.The greater the viscosity is,the shorter the amplitude and the wavelength are.展开更多
The laser bonding technology between the Zr41 Ti14 Cu12 Ni10 Be23 bulk metallic glass and zirconium metal was investigated under welding parameters of 1.3 kW and 7 m/min. The welded bead, microstructure, and micro-har...The laser bonding technology between the Zr41 Ti14 Cu12 Ni10 Be23 bulk metallic glass and zirconium metal was investigated under welding parameters of 1.3 kW and 7 m/min. The welded bead, microstructure, and micro-hardness of the welded joint were examined by Keyence, transmission electron microscopy, scanning electron microscopy, and Vickers hardness, respectively. The experimental results showed that the Zr41 Ti14 Cu12 Ni10 Be2 bulk metallic glass and zirconium metal were successfully bonded together. The Zr41 Ti14 Cu12 Ni10 Be2 in the base material zone maintained amorphous structure, and the welding fusion zone kept the hardness as high as as-received BMG. Therefore, the laser welding technology can be used to achieve successful bonding of bulk metallic glasses and crystallization metal.展开更多
In the current microwelding process using femtosecond(fs) laser between dissimilar materials,surface polishing and pressure assistance,so-called optical contact,are believed necessary.In this paper,direct welding of s...In the current microwelding process using femtosecond(fs) laser between dissimilar materials,surface polishing and pressure assistance,so-called optical contact,are believed necessary.In this paper,direct welding of soda lime glass and Kovar alloy using a fs laser is investigated to overcome the limit of optical contact.The processing of fs laser welding is comprehensively studied by varying the laser power,welding velocity and the number of welding.The shear joining strength is as high as 2 MPa.The cross-section of glass-Kovar alloy joints,the elemental diffusion and the fracture behavior of welded joints were studied.The results show that the fs laser irradiates the surface of Kovar alloy,micron/nanometer-sized metal particles are generated.These particles perform the role as an adhesive part in the welding process.It is believed that the Si atoms diffuses to Kovar alloy from the glass and partially replaces the Fe^(2+) ions on the surface of Kovar alloy,indicating that the mixing and interdiffusion of materials have occurred during the welding process.Finally,the welded sample was tested and has excellent water resistance and sealing property.Furthermore,to justify that this method can be applied to other stack ups,the glass-copper,the glass-Al6063 and sapphire-ceramic are also welded together.This work greatly simplifies the fs laser microwelding process and promotes its industrial applications,such as optoelectronic devices,medical devices and MEMS.展开更多
Background and Objective: Unwanted hair growth is a discomforting issue affecting both genders. People have tried various methods to get rid of this situation. This study aims to evaluate the efficacy and safety of a ...Background and Objective: Unwanted hair growth is a discomforting issue affecting both genders. People have tried various methods to get rid of this situation. This study aims to evaluate the efficacy and safety of a combined Alexandrite and Nd:YAG laser treatment for permanent hair removal, drawing insights from existing literature. Materials and Methods:This study included a total of 2127 patients (302 males, 1825 females) aged 18 - 65, with complete data, who underwent hair removal treatment between December 2018 and April 2021. These patients were treated using the Duetta laser system (Quanta system, Samarate, Italy), combining Alexandrite 755 nm and Nd:YAG 1064 nm wavelengths. The patients’ skin types were classified according to the Fitzpatrick classification scale. Target area/areas for laser hair removal was/were determined. Laser parameters, pulse counts, pain levels assessed through the Visual Pain Scale (VPS), and patient satisfaction were documented based on skin types. Findings: Across various skin types, Types I - II exhibited the highest treatment success rates (87%), with the axillary region achieving the highest rate (83%) and the face region achieving the lowest rate (75%). Pain scale analysis indicated that 98% of patients tolerated the procedure well. Patient satisfaction levels exceeded 90%. Evaluation of complication rates revealed minimal occurrences. Conclusion: The combined Alexandrite and Nd:YAG laser system demonstrates both efficacy and safety across diverse skin types, attributed to its notable success rates, minimal adverse effects, and high patient tolerance.展开更多
In double-pulse laser-induced breakdown spectroscopy(DP-LIBS), the collinear femtosecond double-pulse laser configuration is experimentally investigated with different initial sample temperatures using a Ti:sapphire l...In double-pulse laser-induced breakdown spectroscopy(DP-LIBS), the collinear femtosecond double-pulse laser configuration is experimentally investigated with different initial sample temperatures using a Ti:sapphire laser. The glass sample is ablated to produce the plasma spectroscopy. During the experiment, the detected spectral lines include two Na(I) lines(589.0 nm and 589.6 nm) and one Ca(I) line at the wavelength of 585.7 nm. The emission lines are measured at room temperature(22 ℃) and three higher initial sample temperatures(T_s?=?100 ℃, 200 ℃, and 250 ℃). The inter-pulse delay time ranges from-250 ps to 250 ps.The inter-pulse delay time and the sample temperature strongly influence the spectral intensity,and the spectral intensity can be significantly enhanced by increasing the sample temperature and selecting the optimized inter-pulse time. For the same inter-pulse time of 0 ps(single-pulse LIBS), the enhancement ratio is approximately 2.5 at T_s?=?200 ℃ compared with that obtained at T_s?=?22 ℃. For the same inter-pulse time of 150 ps, the enhancement ratio can be up to 4 at T_s?=?200 ℃ compared with that obtained at T_s?=?22 ℃. The combined enhancement effects of the different initial sample temperatures and the double-pulse configuration in femtosecond LIBS are much stronger than that of the different initial sample temperatures or the double-pulse configuration only.展开更多
We report on the microstructure formation in Foturan glass, induced by 1 kHz, 120 femtosecond laser irradiation. It is found that the line-shaped filamentation, not void array tends to be formed in this glass. This is...We report on the microstructure formation in Foturan glass, induced by 1 kHz, 120 femtosecond laser irradiation. It is found that the line-shaped filamentation, not void array tends to be formed in this glass. This is different from our previous experimental results in fused silica and BK7 glasses. A possible mechanism Ag+ captures the free electrons generated by laser, is proposed to explain the observed phenomena.展开更多
A femtosecond laser with 800 nm, 250 kHz and 150 fs was used to irradiate Sm^3+-doped Li2O- Nb2O5-SiO2 glass. At the initial stage of the laser irradiation, a white emission was observed near the focal point of the l...A femtosecond laser with 800 nm, 250 kHz and 150 fs was used to irradiate Sm^3+-doped Li2O- Nb2O5-SiO2 glass. At the initial stage of the laser irradiation, a white emission was observed near the focal point of the laser beam inside the glass. After 20 second irradiation, a red and blue emission began to emerge. From the micro-Raman spectra, we found that the crystal spot has formed at the focal point of the femtosecond laser beam in the glass. The mechanism of the observed phenomena is discussed.展开更多
This paper studies the photosensitive effect of cerium oxide on the precipitation of Ag nanoparticles after femtosecond laser irradiating into silicate glass and successive annealing.Spectroscopy analysis and diffract...This paper studies the photosensitive effect of cerium oxide on the precipitation of Ag nanoparticles after femtosecond laser irradiating into silicate glass and successive annealing.Spectroscopy analysis and diffraction efficiency measurements show that the introduction of cerium oxide may increase the concentration of Ag atoms in the femtosecond laser-irradiated regions resulting from the photoreduction reaction Ce^3+ + Ag^+ → Ce^4+ + Ag^0 via multiphoton excitation.These results promote the aggregation of Ag nanopartieles during the annealing process. It is also found that different concentrations of cerium oxide may influence the Ag nanoparticle precipitation in the corresponding glass.展开更多
A Co^2+:spinel passively Q-switched erbium-ytterbium-phosphate glass bonded laser pumped at 940 nm is reported.A pulse energy of 210 μJ, a peak power over 70 kW, and beam quality M-2 parameter of 1.2 are obtained u...A Co^2+:spinel passively Q-switched erbium-ytterbium-phosphate glass bonded laser pumped at 940 nm is reported.A pulse energy of 210 μJ, a peak power over 70 kW, and beam quality M-2 parameter of 1.2 are obtained under a pump power of 235 mW. An unbonded laser output experiment with the same dimension of the active material and the saturable absorber as the bonded laser output experiment is carried out. The reason why the output in the bonded laser is improved is determined.展开更多
In this paper, we study the effect of spherical aberrations on the light intensity and the temperature distribution in the focal region in a 250-kHz femtosecond laser irradiated Ag^+-doped borosilicate glass. When a ...In this paper, we study the effect of spherical aberrations on the light intensity and the temperature distribution in the focal region in a 250-kHz femtosecond laser irradiated Ag^+-doped borosilicate glass. When a focused beam goes through an interface between air and glass, spherical aberration will result in the separation of the focal point and then cause a clear change of the light intensity distribution along the incident direction. That phenomenon will further influence the longitudinal cross-section temperature distribution in glass. Here we use Ag nanoparticle formation as a marker for establishing temperature distribution and we find that the formation of nanoparticle shows a strong dependence on the temperature field and the detailed precipitation process is also discussed.展开更多
The preparation and characteristics of a new transparent glass ceramic were described. Crystal phase particles with nanometer size were successfully precipitated in glass matrix, which was confirmed to be one of indiu...The preparation and characteristics of a new transparent glass ceramic were described. Crystal phase particles with nanometer size were successfully precipitated in glass matrix, which was confirmed to be one of indium aluminum zinc oxide compounds (InxAlrZn2O). The presence of aluminum (A1) and indium (In) impurities in the zinc oxides (ZnO) crystal lattice leads to some changes of the carrier concentration in the material and then promote the sharply changes of transmission spectra in IR range wavelength. And subsequently, the IR cut-off edge blue shifted from 5.5 pm in base glass to 3 μm in transparent glass ceramic sample. Furthermore, passive Q switched 1.54 ktm Er glass laser pulses with pulse energy of 10 mJ and pulse width of 800 ns were successfully obtained by using the cobalt doped transparent glass ceramic as a saturable absorber.展开更多
文摘We report novel results on top-down percussion drilling in different glasses with femtosecond laser GHz-bursts.Thanks to this particular regime of light–matter interaction,combining non-linear absorption and thermal cumulative effects,we obtained crack-free holes of aspect ratios exceeding 30 in sodalime and 70 in fused silica.The results are discussed in terms of inner wall morphology,aspect ratio and drilling speed.
文摘BACKGROUND This case of gestational gingival tumor is huge and extremely rare in clinical practice.As the growth location of this gingival tumor is in the upper anterior tooth area,it seriously affects the pregnant woman's speech and food,causing great pain to the patient.The use of Nd:YGA water mist laser to remove the gingival tumor resulted in minimal intraoperative bleeding,minimal adverse reactions,and good postoperative healing,which is worthy of clinical promotion and application.CASE SUMMARY The patient,a pregnant woman,reported a large lump in her mouth on the first day of postpartum treatment.Based on medical history and clinical examination,the diagnosis was diagnosed as gestational gingival tumor.Postoperative pathological biopsy also confirmed this diagnosis.The use of Nd:YAG water mist laser to remove the tumor resulted in minimal intraoperative bleeding,clear surgical field of view,short surgical time,and good postoperative healing.CONCLUSION In comparison to traditional surgery,Nd:YAG water mist laser surgery is minimally invasive,minimizes cell damage,reduces bleeding,ensures a clear field of vision,and virtually eliminates postoperative edema,carbonization,and the risk of cross infection.It has unique advantages in oral soft tissue surgery for pregnant patients.Therefore,the clinical application of Nd:YAG water mist laser for the treatment of gestational gingival tumors is an ideal choice.
基金supported by the Natural Science Foundation of Hebei Province,China (No. E2008000072)the Hebei Science and Technology Research and Development Guiding Plan (No. 07215136)Hebei Education Department Research Plan (No. Z2008305)
文摘The effects of femtosecond laser ablation on the surface characteristics and microstructure of a bulk TiCuPdZr glass alloy were investigated. The heat influence zone of femtosecond laser ablated with a laser energy of 100 μJ exhibits a ripple-like feather, while a porous structure appears on the surface of the specimen ablated by a 200 μJ femtosecond laser. The contents of Ti, Zr, and Pd on the ablated surface decrease and that of Cu increases with increasing laser energy. The crystallization process occurs on the glass alloy specimens during femtosecond laser ablation, and the crystallinity of a 100 μJ femtosecond laser-ablated specimen is greater than that of a 200 μJ femtosecond laser-ablated one.
文摘The Yb3^+ -doped silicate, phosphate and borophosphate laser glasses were prepared by means of conventional melt quenching technology. The physical and spectral properties of the glasses were investigated. The results show that, due to the existence of OH^-, the fluorescence lifetime of phosphate glass is shorter than that of silicate glass, so silicate glass has better spectral properties than phosphate glass. Silicate glass has better mechanical and thermal properties than phosphate glass, but with the addition of B2O3, mechanical and thermal properties of phosphate glass are improved greatly without fluorescence quenching effect. This kind of borophosphate glass can be used in high average power solid state lasers.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10572002,10732010,and 11332002)
文摘The details of the special three-dimensional micro-nano scale ripples with a period of hundreds of microns on the surfaces of a Zr-based and a La-based metallic glass irradiated separately by single laser pulse are investigated.We use the small-amplitude capillary wave theory to unveil the ripple formation mechanism through considering each of the molten metallic glasses as an incompressible viscous fluid.A generalized model is presented to describe the special morphology,which fits the experimental result well.It is also revealed that the viscosity brings about the biggest effect on the monotone decreasing nature of the amplitude and the wavelength of the surface ripples.The greater the viscosity is,the shorter the amplitude and the wavelength are.
基金Funded by the National Natural Science Foundation of China(Nos.51222508 and 51175211)the Science&Technology Research Projects of Hubei Provincial Committee of Education(No.Q20133004)
文摘The laser bonding technology between the Zr41 Ti14 Cu12 Ni10 Be23 bulk metallic glass and zirconium metal was investigated under welding parameters of 1.3 kW and 7 m/min. The welded bead, microstructure, and micro-hardness of the welded joint were examined by Keyence, transmission electron microscopy, scanning electron microscopy, and Vickers hardness, respectively. The experimental results showed that the Zr41 Ti14 Cu12 Ni10 Be2 bulk metallic glass and zirconium metal were successfully bonded together. The Zr41 Ti14 Cu12 Ni10 Be2 in the base material zone maintained amorphous structure, and the welding fusion zone kept the hardness as high as as-received BMG. Therefore, the laser welding technology can be used to achieve successful bonding of bulk metallic glasses and crystallization metal.
基金Project(GKZY2119502) supported by the Special Funds for Local Scientific and Technological Development guided by the Central Government,ChinaProject(JGY2021001) supported by the Innovation Project of Guangxi Graduate Education,China。
文摘In the current microwelding process using femtosecond(fs) laser between dissimilar materials,surface polishing and pressure assistance,so-called optical contact,are believed necessary.In this paper,direct welding of soda lime glass and Kovar alloy using a fs laser is investigated to overcome the limit of optical contact.The processing of fs laser welding is comprehensively studied by varying the laser power,welding velocity and the number of welding.The shear joining strength is as high as 2 MPa.The cross-section of glass-Kovar alloy joints,the elemental diffusion and the fracture behavior of welded joints were studied.The results show that the fs laser irradiates the surface of Kovar alloy,micron/nanometer-sized metal particles are generated.These particles perform the role as an adhesive part in the welding process.It is believed that the Si atoms diffuses to Kovar alloy from the glass and partially replaces the Fe^(2+) ions on the surface of Kovar alloy,indicating that the mixing and interdiffusion of materials have occurred during the welding process.Finally,the welded sample was tested and has excellent water resistance and sealing property.Furthermore,to justify that this method can be applied to other stack ups,the glass-copper,the glass-Al6063 and sapphire-ceramic are also welded together.This work greatly simplifies the fs laser microwelding process and promotes its industrial applications,such as optoelectronic devices,medical devices and MEMS.
文摘Background and Objective: Unwanted hair growth is a discomforting issue affecting both genders. People have tried various methods to get rid of this situation. This study aims to evaluate the efficacy and safety of a combined Alexandrite and Nd:YAG laser treatment for permanent hair removal, drawing insights from existing literature. Materials and Methods:This study included a total of 2127 patients (302 males, 1825 females) aged 18 - 65, with complete data, who underwent hair removal treatment between December 2018 and April 2021. These patients were treated using the Duetta laser system (Quanta system, Samarate, Italy), combining Alexandrite 755 nm and Nd:YAG 1064 nm wavelengths. The patients’ skin types were classified according to the Fitzpatrick classification scale. Target area/areas for laser hair removal was/were determined. Laser parameters, pulse counts, pain levels assessed through the Visual Pain Scale (VPS), and patient satisfaction were documented based on skin types. Findings: Across various skin types, Types I - II exhibited the highest treatment success rates (87%), with the axillary region achieving the highest rate (83%) and the face region achieving the lowest rate (75%). Pain scale analysis indicated that 98% of patients tolerated the procedure well. Patient satisfaction levels exceeded 90%. Evaluation of complication rates revealed minimal occurrences. Conclusion: The combined Alexandrite and Nd:YAG laser system demonstrates both efficacy and safety across diverse skin types, attributed to its notable success rates, minimal adverse effects, and high patient tolerance.
基金support by National Natural Science Foundation of China (Grant Nos. 11674128, 11504129, and 11674124)Jilin Province Scientific and Technological Development Program, China (Grant No. 20170101063JC)Fundamental Research Project of Chinese State Key Laboratory of Laser Interaction with Matter (Grant No. SKLLIM1605)
文摘In double-pulse laser-induced breakdown spectroscopy(DP-LIBS), the collinear femtosecond double-pulse laser configuration is experimentally investigated with different initial sample temperatures using a Ti:sapphire laser. The glass sample is ablated to produce the plasma spectroscopy. During the experiment, the detected spectral lines include two Na(I) lines(589.0 nm and 589.6 nm) and one Ca(I) line at the wavelength of 585.7 nm. The emission lines are measured at room temperature(22 ℃) and three higher initial sample temperatures(T_s?=?100 ℃, 200 ℃, and 250 ℃). The inter-pulse delay time ranges from-250 ps to 250 ps.The inter-pulse delay time and the sample temperature strongly influence the spectral intensity,and the spectral intensity can be significantly enhanced by increasing the sample temperature and selecting the optimized inter-pulse time. For the same inter-pulse time of 0 ps(single-pulse LIBS), the enhancement ratio is approximately 2.5 at T_s?=?200 ℃ compared with that obtained at T_s?=?22 ℃. For the same inter-pulse time of 150 ps, the enhancement ratio can be up to 4 at T_s?=?200 ℃ compared with that obtained at T_s?=?22 ℃. The combined enhancement effects of the different initial sample temperatures and the double-pulse configuration in femtosecond LIBS are much stronger than that of the different initial sample temperatures or the double-pulse configuration only.
基金Project supported by National Basic Research Program of China (Grant No. 2006CB806000)Cheng Ya’ 100 Talents Program of the Chinese Academy of Sciences+1 种基金Shanghai Pujiang ProgramNational Outstanding Youth Foundation
文摘We report on the microstructure formation in Foturan glass, induced by 1 kHz, 120 femtosecond laser irradiation. It is found that the line-shaped filamentation, not void array tends to be formed in this glass. This is different from our previous experimental results in fused silica and BK7 glasses. A possible mechanism Ag+ captures the free electrons generated by laser, is proposed to explain the observed phenomena.
基金Funded by the National Natural Science Foundation of China (Grant No.50672087 and No.60778039)National Basic Research Program of China (2006CB806000)+1 种基金National High Technology Program of China (2006AA03Z304)supported by Program for Changjiang Scholars and Innovative Research Team in University
文摘A femtosecond laser with 800 nm, 250 kHz and 150 fs was used to irradiate Sm^3+-doped Li2O- Nb2O5-SiO2 glass. At the initial stage of the laser irradiation, a white emission was observed near the focal point of the laser beam inside the glass. After 20 second irradiation, a red and blue emission began to emerge. From the micro-Raman spectra, we found that the crystal spot has formed at the focal point of the femtosecond laser beam in the glass. The mechanism of the observed phenomena is discussed.
基金Project supported by the National Basic Research Program of China (Grant No 2006CB806000b)the Shanghai Leading Academic Discipline Project (Grant No S30105)
文摘This paper studies the photosensitive effect of cerium oxide on the precipitation of Ag nanoparticles after femtosecond laser irradiating into silicate glass and successive annealing.Spectroscopy analysis and diffraction efficiency measurements show that the introduction of cerium oxide may increase the concentration of Ag atoms in the femtosecond laser-irradiated regions resulting from the photoreduction reaction Ce^3+ + Ag^+ → Ce^4+ + Ag^0 via multiphoton excitation.These results promote the aggregation of Ag nanopartieles during the annealing process. It is also found that different concentrations of cerium oxide may influence the Ag nanoparticle precipitation in the corresponding glass.
文摘A Co^2+:spinel passively Q-switched erbium-ytterbium-phosphate glass bonded laser pumped at 940 nm is reported.A pulse energy of 210 μJ, a peak power over 70 kW, and beam quality M-2 parameter of 1.2 are obtained under a pump power of 235 mW. An unbonded laser output experiment with the same dimension of the active material and the saturable absorber as the bonded laser output experiment is carried out. The reason why the output in the bonded laser is improved is determined.
基金supported by the National Natural Science Foundation of China (Grant No.60908007)the Shanghai Leading Academic Discipline Project,China (Grant No.S30105)
文摘In this paper, we study the effect of spherical aberrations on the light intensity and the temperature distribution in the focal region in a 250-kHz femtosecond laser irradiated Ag^+-doped borosilicate glass. When a focused beam goes through an interface between air and glass, spherical aberration will result in the separation of the focal point and then cause a clear change of the light intensity distribution along the incident direction. That phenomenon will further influence the longitudinal cross-section temperature distribution in glass. Here we use Ag nanoparticle formation as a marker for establishing temperature distribution and we find that the formation of nanoparticle shows a strong dependence on the temperature field and the detailed precipitation process is also discussed.
基金the National Natrural Science Foundation of China(Nos. 50902137 and 60937003)
文摘The preparation and characteristics of a new transparent glass ceramic were described. Crystal phase particles with nanometer size were successfully precipitated in glass matrix, which was confirmed to be one of indium aluminum zinc oxide compounds (InxAlrZn2O). The presence of aluminum (A1) and indium (In) impurities in the zinc oxides (ZnO) crystal lattice leads to some changes of the carrier concentration in the material and then promote the sharply changes of transmission spectra in IR range wavelength. And subsequently, the IR cut-off edge blue shifted from 5.5 pm in base glass to 3 μm in transparent glass ceramic sample. Furthermore, passive Q switched 1.54 ktm Er glass laser pulses with pulse energy of 10 mJ and pulse width of 800 ns were successfully obtained by using the cobalt doped transparent glass ceramic as a saturable absorber.