Adhesive is used in the laser weld bonding Mg to A1 alloys process, in order to improve the property of laser welding joint. The effect of adhesive on the microstrnctures in laser weld bonding AZ31B Mg alloy to 6061Al...Adhesive is used in the laser weld bonding Mg to A1 alloys process, in order to improve the property of laser welding joint. The effect of adhesive on the microstrnctures in laser weld bonding AZ31B Mg alloy to 6061Al alloy are observed by scanning electron microscopy and transmission electron microscope. The results show that the decomposition of the adhesive makes influence on the crystal structure of the Mg fusion zone, which forms the C-Mn precipitates. The morphology of Mg-Al intermetallics is changed, when the adhesive decomposition gas bubble floats out of the fusion zone. Dislocations are formed at the bottom of Al fusion zone with the effect of adhesive decomposition and pulse laser power.展开更多
A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP...A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP ridge waveguide is designed and fabricated on an InP/AIGaInAs multiple quantum well epitaxial layer structure wafer by using i-line lithography. Then, a silicon waveguide platform including a laser mounting stage is designed and fabricated on a silicon-on-insulator substrate. The single mode laser is flip-chip bonded on the laser mounting stage. The lasing light is butt-coupling to the silicon waveguide. The laser power output from a silicon waveguide is 1.3roW, and the threshold is 37mA at room temperature and continuous wave operation.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
By using a two-dimensional Monte-Carlo classical ensemble method, we investigate the double ionization（DI） process of the CS_2 molecule with different bond lengths in an 800-nm intense laser field. The double ioniza...By using a two-dimensional Monte-Carlo classical ensemble method, we investigate the double ionization（DI） process of the CS_2 molecule with different bond lengths in an 800-nm intense laser field. The double ionization probability presents a ＂knee＂ structure with equilibrium internuclear distance R = 2.9245 a.u.（a.u. is short for atomic unit）. As the bond length of CS increases, the DI probability is enhanced and the ＂knee＂ structure becomes less obvious. In addition,the momentum distribution of double ionized electrons is also investigated, which shows the momentum mostly distributed in the first and third quadrants with equilibrium internuclear distance R = 2.9245 a.u. As the bond length of CS increases,the electron momentum becomes evenly distributed in the four quadrants. Furthermore, the energy distributions and the corresponding trajectories of the double-ionized electrons versus time are also demonstrated, which show that the bond length of CS in the CS_2 molecule plays a key role in the DI process.展开更多
Epi-up and epi-down bonding of high power 980nm lasers have been studied in terms of bonding process, thermal behavior, optical performances, thermal stress effects and long-term laser reliability. We demonstrated tha...Epi-up and epi-down bonding of high power 980nm lasers have been studied in terms of bonding process, thermal behavior, optical performances, thermal stress effects and long-term laser reliability. We demonstrated that epi-down bonding can offer lower thermal resistance and improved optical performances without significantly degrading the long-term laser reliability.展开更多
Thermal characteristics are numerically investigated for the hybrid AlGaInAs/InP on silicon microring lasers with different ring radii and widths. Low threshold current and low active region temperature rise are expec...Thermal characteristics are numerically investigated for the hybrid AlGaInAs/InP on silicon microring lasers with different ring radii and widths. Low threshold current and low active region temperature rise are expected for a microring laser with a narrow ring width. Based on the thermal analysis and the 3D simulation for mode characteristics, a hybrid AlGaInAs/InP on silicon microring lasers with an inner n-electrode laterally confined by the p-electrode metallic layer is fabricated using an adhesive bonding technique. A threshold current of 4 mA is achieved for a hybrid microring laser with a radius of 20 μm and a ring width of 3.5 μm at 12°C, and the corresponding threshold current density is as low as 1 kA∕cm^2. The influence of the location of silicon waveguide on output performance is studied experimentally for improving the output coupling efficiency. Furthermore,continuous-wave electrically injected lasing up to 55°C is realized for a hybrid microring laser with a radiusof 30 μm and a ring width of 3 μm.展开更多
This work presents a novel design of Ka-band(33 GHz)filtering packaging antenna(FPA)that features broadband and great filtering response,and is based on glass packaging material and through-glass via(TGV)technologies....This work presents a novel design of Ka-band(33 GHz)filtering packaging antenna(FPA)that features broadband and great filtering response,and is based on glass packaging material and through-glass via(TGV)technologies.Compared to traditional packaging materials(printed circuit board,low temperature co-fired ceramic,Si,etc.),TGVs are more suitable for miniaturization(millimeter-wave three-dimensional(3D)packaging devices)and have superior microwave performance.Glass substrate can realize 3D high-density interconnection through bonding technology,while the coefficient of thermal expansion(CTE)matches that of silicon.Furthermore,the stacking of glass substrate enables high-density interconnections and is compatible with micro-electro-mechanical system technology.The proposed antenna radiation patch is composed of a patch antenna and a bandpass filter(BPF)whose reflection coefficients are almost complementary.The BPF unit has three pairs ofλg/4 slots(defect microstrip structure,DMS)and twoλg/2 U-shaped slots(defect ground structure,DGS).The proposed antenna achieves large bandwidth and high radiation efficiency,which may be related to the stacking of glass substrate and TGV feed.In addition,the introduction of four radiation nulls can effectively improve the suppression level in the stopband.To demonstrate the performance of the proposed design,a 33-GHz broadband filtering antenna is optimized,debugged,and measured.The antenna could achieve|S11|<-10 dB in 29.4‒36.4 GHz,and yield an impedance matching bandwidth up to 21.2%,with the stopband suppression level at higher than 16.5 dB.The measurement results of the proposed antenna are a realized gain of~6.5 dBi and radiation efficiency of~89%.展开更多
基金Acknowledgements The authors gratefully acknowledge tile sponsorship from China Postdoctoral Science Foundation （2102M510803 ） and Doctoral Scientific Research Foundation of Liaoning Province （ No. 201 11024）.
文摘Adhesive is used in the laser weld bonding Mg to A1 alloys process, in order to improve the property of laser welding joint. The effect of adhesive on the microstrnctures in laser weld bonding AZ31B Mg alloy to 6061Al alloy are observed by scanning electron microscopy and transmission electron microscope. The results show that the decomposition of the adhesive makes influence on the crystal structure of the Mg fusion zone, which forms the C-Mn precipitates. The morphology of Mg-Al intermetallics is changed, when the adhesive decomposition gas bubble floats out of the fusion zone. Dislocations are formed at the bottom of Al fusion zone with the effect of adhesive decomposition and pulse laser power.
基金Supported by the National Basic Research Program of China under Grant No 2012CB933501the National Natural Science Foundation of China under Grant Nos 61307033,61274070,61137003 and 61321063
文摘A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP ridge waveguide is designed and fabricated on an InP/AIGaInAs multiple quantum well epitaxial layer structure wafer by using i-line lithography. Then, a silicon waveguide platform including a laser mounting stage is designed and fabricated on a silicon-on-insulator substrate. The single mode laser is flip-chip bonded on the laser mounting stage. The lasing light is butt-coupling to the silicon waveguide. The laser power output from a silicon waveguide is 1.3roW, and the threshold is 37mA at room temperature and continuous wave operation.
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Project supported by the National Natural Science Foundation of China(Grant Nos.11574117 and11604131)
文摘By using a two-dimensional Monte-Carlo classical ensemble method, we investigate the double ionization（DI） process of the CS_2 molecule with different bond lengths in an 800-nm intense laser field. The double ionization probability presents a ＂knee＂ structure with equilibrium internuclear distance R = 2.9245 a.u.（a.u. is short for atomic unit）. As the bond length of CS increases, the DI probability is enhanced and the ＂knee＂ structure becomes less obvious. In addition,the momentum distribution of double ionized electrons is also investigated, which shows the momentum mostly distributed in the first and third quadrants with equilibrium internuclear distance R = 2.9245 a.u. As the bond length of CS increases,the electron momentum becomes evenly distributed in the four quadrants. Furthermore, the energy distributions and the corresponding trajectories of the double-ionized electrons versus time are also demonstrated, which show that the bond length of CS in the CS_2 molecule plays a key role in the DI process.
文摘Epi-up and epi-down bonding of high power 980nm lasers have been studied in terms of bonding process, thermal behavior, optical performances, thermal stress effects and long-term laser reliability. We demonstrated that epi-down bonding can offer lower thermal resistance and improved optical performances without significantly degrading the long-term laser reliability.
基金supported by the High Technology Project of China under grant 2012AA012202NSFC/RGC joint project under grant 61431166003
文摘Thermal characteristics are numerically investigated for the hybrid AlGaInAs/InP on silicon microring lasers with different ring radii and widths. Low threshold current and low active region temperature rise are expected for a microring laser with a narrow ring width. Based on the thermal analysis and the 3D simulation for mode characteristics, a hybrid AlGaInAs/InP on silicon microring lasers with an inner n-electrode laterally confined by the p-electrode metallic layer is fabricated using an adhesive bonding technique. A threshold current of 4 mA is achieved for a hybrid microring laser with a radius of 20 μm and a ring width of 3.5 μm at 12°C, and the corresponding threshold current density is as low as 1 kA∕cm^2. The influence of the location of silicon waveguide on output performance is studied experimentally for improving the output coupling efficiency. Furthermore,continuous-wave electrically injected lasing up to 55°C is realized for a hybrid microring laser with a radiusof 30 μm and a ring width of 3 μm.
基金supported by the Fundamental Research Funds for the Central Universities,China(No.ZYGX2019Z003)。
文摘This work presents a novel design of Ka-band(33 GHz)filtering packaging antenna(FPA)that features broadband and great filtering response,and is based on glass packaging material and through-glass via(TGV)technologies.Compared to traditional packaging materials(printed circuit board,low temperature co-fired ceramic,Si,etc.),TGVs are more suitable for miniaturization(millimeter-wave three-dimensional(3D)packaging devices)and have superior microwave performance.Glass substrate can realize 3D high-density interconnection through bonding technology,while the coefficient of thermal expansion(CTE)matches that of silicon.Furthermore,the stacking of glass substrate enables high-density interconnections and is compatible with micro-electro-mechanical system technology.The proposed antenna radiation patch is composed of a patch antenna and a bandpass filter(BPF)whose reflection coefficients are almost complementary.The BPF unit has three pairs ofλg/4 slots(defect microstrip structure,DMS)and twoλg/2 U-shaped slots(defect ground structure,DGS).The proposed antenna achieves large bandwidth and high radiation efficiency,which may be related to the stacking of glass substrate and TGV feed.In addition,the introduction of four radiation nulls can effectively improve the suppression level in the stopband.To demonstrate the performance of the proposed design,a 33-GHz broadband filtering antenna is optimized,debugged,and measured.The antenna could achieve|S11|<-10 dB in 29.4‒36.4 GHz,and yield an impedance matching bandwidth up to 21.2%,with the stopband suppression level at higher than 16.5 dB.The measurement results of the proposed antenna are a realized gain of~6.5 dBi and radiation efficiency of~89%.
