采用T2Cu和CuSi3焊丝在相同工艺参数下对厚度为1 mm的TC4钛合金及304不锈钢进行焊接,并借助光学显微镜(optical microscopy,OM)和扫描电镜(scanning electron microscopy,SEM)研究了两种焊丝下的TC4/304异种金属焊接熔池冶金行为.对比...采用T2Cu和CuSi3焊丝在相同工艺参数下对厚度为1 mm的TC4钛合金及304不锈钢进行焊接,并借助光学显微镜(optical microscopy,OM)和扫描电镜(scanning electron microscopy,SEM)研究了两种焊丝下的TC4/304异种金属焊接熔池冶金行为.对比分析了不同焊丝成分,尤其是Si元素的加入对TC4/304异种金属接头宏观成形、界面微观组织和力学性能的影响.结果表明,Si元素的加入使液态熔池流动性显著增强,消除了凹陷和孔洞等缺陷,解决了焊缝背部熔合不良问题,焊缝宏观成形显著改善.两种焊丝均有效阻隔了Ti,Fe原子,钛/铜界面未生成Ti-Fe化合物,但在焊缝中心以及铜/钢界面处生成了少量Ti-Fe相.CuSi3焊丝中充足的Si元素不仅使Ti5Si3相形核生长的更加充分,在熔池流动的作用下均匀分布于焊缝中,对接头起到弥散强化作用.与T2Cu焊丝相比,CuSi3焊丝所得接头的抗拉强度提升了81.4%,最高达到366.8 MPa.展开更多
We have proposed and demonstrated hybrid Al Ga In As/Si Fabry–Pérot(FP) lasers, with the FP cavity facet covered by the p-electrode metal for enhancing mode confinement. Continuous-wave lasing is obtained at roo...We have proposed and demonstrated hybrid Al Ga In As/Si Fabry–Pérot(FP) lasers, with the FP cavity facet covered by the p-electrode metal for enhancing mode confinement. Continuous-wave lasing is obtained at room temperature with a threshold current of 45 m A for the hybrid FP laser with a cavity length of 415 μm and a width of 7 μm. Near-field optical microscope images indicate an efficient output emission from the underneath evanescently-coupled silicon waveguide. Furthermore, single-mode lasing with a side-mode suppression-ratio of29 d B and a threshold current of 16 m A is realized for the 150 μm-long hybrid FP laser.展开更多
Polarization insensitive AlGaInAs InP semiconductor optical amplifier is realized at a wavelength of 1550nm.The active layer consists of three tensile strained wells with strain 0 40%.The amplifiers are fabricated ...Polarization insensitive AlGaInAs InP semiconductor optical amplifier is realized at a wavelength of 1550nm.The active layer consists of three tensile strained wells with strain 0 40%.The amplifiers are fabricated to ridge waveguide structure with 7° tilted cavity.The two facets are coated with two layers of anti reflection Ti 3O 5/Al 2O 3 films.Residual facet reflectivity is found to be less than 0 03%.The semiconductor optical amplifer exhibits 20dB of signal gain and 7 2dBm of saturation output power with an excellent polarization insensitivity (less than 0 8dB) at 200mA and 1540nm window.展开更多
Si P微系统是一种高度集成化的系统,其内部可能集成1个或多个DSP、NOR Flash和DDR存储器、AI加速芯片等,有些复杂的微系统还集成了FPGA芯片。由于内部集成了多个微组件,芯片之间相互连接,传统的测试单一微组件的方法并不适用于微系统的...Si P微系统是一种高度集成化的系统,其内部可能集成1个或多个DSP、NOR Flash和DDR存储器、AI加速芯片等,有些复杂的微系统还集成了FPGA芯片。由于内部集成了多个微组件,芯片之间相互连接,传统的测试单一微组件的方法并不适用于微系统的测试。提出了一套DSP微组件测试方法,该系统包括1块专门的测试板、可调试的电脑测试环境和JTAG通信。与单一的DSP裸芯测试相比,它可以快速稳定地实现DSP微组件的性能测试,满足大批量生产测试的需求。展开更多
基金supported by the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(No.QYZDJ-SSW-JSC002)the NSFC/RGC Joint Project(No.61431166003)the National Natural Science Foundation of China(No.61377105)
文摘We have proposed and demonstrated hybrid Al Ga In As/Si Fabry–Pérot(FP) lasers, with the FP cavity facet covered by the p-electrode metal for enhancing mode confinement. Continuous-wave lasing is obtained at room temperature with a threshold current of 45 m A for the hybrid FP laser with a cavity length of 415 μm and a width of 7 μm. Near-field optical microscope images indicate an efficient output emission from the underneath evanescently-coupled silicon waveguide. Furthermore, single-mode lasing with a side-mode suppression-ratio of29 d B and a threshold current of 16 m A is realized for the 150 μm-long hybrid FP laser.
文摘Polarization insensitive AlGaInAs InP semiconductor optical amplifier is realized at a wavelength of 1550nm.The active layer consists of three tensile strained wells with strain 0 40%.The amplifiers are fabricated to ridge waveguide structure with 7° tilted cavity.The two facets are coated with two layers of anti reflection Ti 3O 5/Al 2O 3 films.Residual facet reflectivity is found to be less than 0 03%.The semiconductor optical amplifer exhibits 20dB of signal gain and 7 2dBm of saturation output power with an excellent polarization insensitivity (less than 0 8dB) at 200mA and 1540nm window.
