A four-stage cascaded variable optical attenuator(VOA)with a large attenuation range is presented.The VOA is based on a Mach–Zehnder interferometer(MZI)and fabricated in a silica-based planar lightwave circuit(PLC)pl...A four-stage cascaded variable optical attenuator(VOA)with a large attenuation range is presented.The VOA is based on a Mach–Zehnder interferometer(MZI)and fabricated in a silica-based planar lightwave circuit(PLC)platform.The thermo-optic effect is used to achieve intensity modulation.The measured maximum attenuation of the four-stage cascaded VOA is 88.38 d B.The chip is also tested in a quantum key distribution(QKD)system to generate signal and decoy states.The mean photon number after attenuation of the four-stage cascaded VOA is less than 0.1,which can meet the requirement of QKD.展开更多
【目的】构建pEGFP-N1-LC3真核表达载体,并将其转染进人胚肾细胞293T,通过Earle's盐平衡液(Balanced salt solution,EBSS)饥饿诱导观察细胞自噬现象。【方法】RT-PCR扩增LC3基因,并将其插入pEGFP-N1真核表达载体构建重组质粒。将重...【目的】构建pEGFP-N1-LC3真核表达载体,并将其转染进人胚肾细胞293T,通过Earle's盐平衡液(Balanced salt solution,EBSS)饥饿诱导观察细胞自噬现象。【方法】RT-PCR扩增LC3基因,并将其插入pEGFP-N1真核表达载体构建重组质粒。将重组质粒转染至人胚肾细胞293T,显微镜观察、Western blot检测GFP-LC3融合蛋白表达情况。对转染细胞进行Earle's盐平衡液饥饿诱导,通过Western blot验证自噬指标,激光共聚焦显微镜观察自噬泡形成。【结果】成功构建pEGFP-N1-LC3真核表达载体,并在293T细胞中成功表达目的蛋白,在进行Earle's盐平衡液饥饿诱导后观察到自噬泡的形成,Western blot检测到LC3-Ⅰ向LC3-Ⅱ的转化。【结论】本实验为研究自噬在癌细胞病理进程中的机制提供了实验素材。展开更多
Silica-based planar lightwave circuit(PLC)devices can reduce transmission loss and cost in a quantum key distribution(QKD)system,and have potential applications in integration and production.A PLC-based quantum decodi...Silica-based planar lightwave circuit(PLC)devices can reduce transmission loss and cost in a quantum key distribution(QKD)system,and have potential applications in integration and production.A PLC-based quantum decoding integrated chip for multi-protocols is designed and fabricated,which is composed of variable optical splitters(VOSs),asymmetric Mach-Zehnder interferometers(AMZIs),and variable directional couplers(VDCs).Balanced pulse-pairs of four outputs are obtained simultaneously with measured delay times of 405 ps and 402 ps,respectively.The chip has advantages in achieving high interference visibility and low quantum bit error rate(QBER).展开更多
Since the advent of three-dimensional photonic integrated circuits,the realization of efficient and compact optical interconnection between layers has become an important development direction.A vertical interlayer co...Since the advent of three-dimensional photonic integrated circuits,the realization of efficient and compact optical interconnection between layers has become an important development direction.A vertical interlayer coupler between two silicon layers is presented in this paper.The coupling principle of the directional coupler is analyzed,and the traditional method of using a pair of vertically overlapping inverse taper structures is improved.For the coupling of two rectangular waveguide layers,a pair of nonlinear tapers with offset along the transmission direction is demonstrated.For the coupling of two ridge waveguide layers,a nonlinear taper in each layer is used to achieve high coupling efficiency.The simulation results show that the coupling efficiency of the two structures can reach more than 90%in a wavelength range from 1500 nm to 1650 nm.Moreover,the crosstalk is reduced to less than-50 d B by using multimode waveguides at intersections.The vertical interlayer coupler with a nonlinear taper is expected to realize the miniaturization and dense integration of photonic integrated chips.展开更多
基金the National Key Research and Development Program of China(Grant No.2019YFB2203504)Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB43000000)the Natural Science Foundation of Anhui Province,China(Grant No.1908085QF274)。
文摘A four-stage cascaded variable optical attenuator(VOA)with a large attenuation range is presented.The VOA is based on a Mach–Zehnder interferometer(MZI)and fabricated in a silica-based planar lightwave circuit(PLC)platform.The thermo-optic effect is used to achieve intensity modulation.The measured maximum attenuation of the four-stage cascaded VOA is 88.38 d B.The chip is also tested in a quantum key distribution(QKD)system to generate signal and decoy states.The mean photon number after attenuation of the four-stage cascaded VOA is less than 0.1,which can meet the requirement of QKD.
基金Project supported by the National Key Research and Development Program of China(Grant No.2018YFA0306403)the National Nature Science Foundation of China(Grant No.61805232).
文摘Silica-based planar lightwave circuit(PLC)devices can reduce transmission loss and cost in a quantum key distribution(QKD)system,and have potential applications in integration and production.A PLC-based quantum decoding integrated chip for multi-protocols is designed and fabricated,which is composed of variable optical splitters(VOSs),asymmetric Mach-Zehnder interferometers(AMZIs),and variable directional couplers(VDCs).Balanced pulse-pairs of four outputs are obtained simultaneously with measured delay times of 405 ps and 402 ps,respectively.The chip has advantages in achieving high interference visibility and low quantum bit error rate(QBER).
基金supported by the National Key Research and Development Program of China(Grant No.2019YFB2203001)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB43000000)the National Natural Science Foundation of China(Grant No.61805232)。
文摘Since the advent of three-dimensional photonic integrated circuits,the realization of efficient and compact optical interconnection between layers has become an important development direction.A vertical interlayer coupler between two silicon layers is presented in this paper.The coupling principle of the directional coupler is analyzed,and the traditional method of using a pair of vertically overlapping inverse taper structures is improved.For the coupling of two rectangular waveguide layers,a pair of nonlinear tapers with offset along the transmission direction is demonstrated.For the coupling of two ridge waveguide layers,a nonlinear taper in each layer is used to achieve high coupling efficiency.The simulation results show that the coupling efficiency of the two structures can reach more than 90%in a wavelength range from 1500 nm to 1650 nm.Moreover,the crosstalk is reduced to less than-50 d B by using multimode waveguides at intersections.The vertical interlayer coupler with a nonlinear taper is expected to realize the miniaturization and dense integration of photonic integrated chips.
