Normalized Mandel Parameter （Q） is introduced as a new measurement oi photon statistics. Dependences of Mandel parameter Q and corresponding normalized Mandel parameter （Q） on photon-counting time interval are exp...Normalized Mandel Parameter （Q） is introduced as a new measurement oi photon statistics. Dependences of Mandel parameter Q and corresponding normalized Mandel parameter （Q） on photon-counting time interval are experimentally investigated for pseudo-thermal light. We demonstrate that （Q） is more appropriate than Q, to measure the statistical deviation from Poisson distribution, because （Q） presents clearly both the intrinsic statistical properties and measuring effects. The advantages of （Q） in charactering nonclassical emissions are also discussed.展开更多
We provide a way to precisely control the geometry of a SiNx nanopore by adjusting the applied electric pulse. The pore is generated by applying the current pulse across a SiNx membrane, which is immersed in potassium...We provide a way to precisely control the geometry of a SiNx nanopore by adjusting the applied electric pulse. The pore is generated by applying the current pulse across a SiNx membrane, which is immersed in potassium chloride solution. We can generate single conical and cylindrical pores with different electric pulses. A theoretical model based on the Poisson and Nernst-Planck equations is employed to simulate the ion transport properties in the channel. In turn, we can analyze pore geometries by fitting the experimental current-voltage （I-V） curves. for the conical pores with a pore size of 0.5-2nm in diameter, the slope angles are around -2.5% to -10%. Moreover, the pore orifice can be enlarged slightly by additional repeating pulses. The conic pore lumen becomes close to a cylindrical channel, resulting in a symmetry I-V transport under positive and negative biases. A qualitative understanding of these effects will help us to prepare useful solid-nanopores as demanded.展开更多
Light amplification due to two-beam coupling is realized in doped polymethyl methacrylate （PMMA） glasses. A coupling gain as large as 14 cm^-1 is obtained. The dynamic behaviour of absorption and light-induced scatt...Light amplification due to two-beam coupling is realized in doped polymethyl methacrylate （PMMA） glasses. A coupling gain as large as 14 cm^-1 is obtained. The dynamic behaviour of absorption and light-induced scattering due to the process of photopolymerization are also studied. The results show that the amplification and its dynamic process enable possible applications of PMMA in optical devices.展开更多
The organic-inorganic hybrid perovskite CH_(3)NH_(3)PbI_(3) has been a good candidate for many optoelectronic applications such as light-emitting diodes due to its unique properties.Optimizing the optical properties o...The organic-inorganic hybrid perovskite CH_(3)NH_(3)PbI_(3) has been a good candidate for many optoelectronic applications such as light-emitting diodes due to its unique properties.Optimizing the optical properties of the CH_(3)NH_(3)PbI_(3) material to improve the device performance is a hot topic.Herein,a new strategy is proposed to enhance the light emission of CH_(3)NH_(3)PbI_(3) phosphor effectively.By adding the reactant CH_(3)NH_(3)I powder in an appropriate proportion and simply grinding,the emission intensity of CH_(3)NH_(3)PbI_(3) is greatly improved.The advantages of the proposed method are swiftness,simplicity and reproducibility,and no requirement for a complex organic ligand.The mechanism of this phenomenon is revealed by x-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy,photoluminescence,and temperature-dependent photoluminescence.This study offers a unique insight for optimizing the optical properties of halide perovskite materials.展开更多
基金Supported by the National Basic Research Programme of China under Grant No 2007CB307002, the Key International S＆T Cooperation Project under Grant No 2005DFA10170, the PCSIRT （No IRT0149）, the National Natural Science Foundations of China under Grant Nos 10334010 and 10604033, the 111 Project （No B07013）, and Tianjin Natural Science Foundation （No 07JCYBJC16600）.
文摘Normalized Mandel Parameter （Q） is introduced as a new measurement oi photon statistics. Dependences of Mandel parameter Q and corresponding normalized Mandel parameter （Q） on photon-counting time interval are experimentally investigated for pseudo-thermal light. We demonstrate that （Q） is more appropriate than Q, to measure the statistical deviation from Poisson distribution, because （Q） presents clearly both the intrinsic statistical properties and measuring effects. The advantages of （Q） in charactering nonclassical emissions are also discussed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61471336,51503207 and 61504146the Joint-Scholar of West Light Foundation of Chinese Academy of Sciences
文摘We provide a way to precisely control the geometry of a SiNx nanopore by adjusting the applied electric pulse. The pore is generated by applying the current pulse across a SiNx membrane, which is immersed in potassium chloride solution. We can generate single conical and cylindrical pores with different electric pulses. A theoretical model based on the Poisson and Nernst-Planck equations is employed to simulate the ion transport properties in the channel. In turn, we can analyze pore geometries by fitting the experimental current-voltage （I-V） curves. for the conical pores with a pore size of 0.5-2nm in diameter, the slope angles are around -2.5% to -10%. Moreover, the pore orifice can be enlarged slightly by additional repeating pulses. The conic pore lumen becomes close to a cylindrical channel, resulting in a symmetry I-V transport under positive and negative biases. A qualitative understanding of these effects will help us to prepare useful solid-nanopores as demanded.
基金Supported by the Ministry of Education of China under Grant Nos 105048 and 704012, the National Natural Science Foundation of China under Grant Nos 10604033 and 10334010, the Cultivation Fund of the Key Scientific and Technical Innovation Project, the Key International S＆T Cooperation Project （2005DFA10170）, the Programme for Changjiang Scholars and Innovative Research Team in University （PCSIRT）, the National Basic Research Programme of China under Grant No 2007CB307002）, the 111 Project the Ministry of Education of China under Grant No B07013, and the Scientific-Technical Cooperation Project of （DAD （VII-B-7）.
文摘Light amplification due to two-beam coupling is realized in doped polymethyl methacrylate （PMMA） glasses. A coupling gain as large as 14 cm^-1 is obtained. The dynamic behaviour of absorption and light-induced scattering due to the process of photopolymerization are also studied. The results show that the amplification and its dynamic process enable possible applications of PMMA in optical devices.
基金the National Natural Science Foundation of China(Grant Nos.11774187 and U1902218)the National Key R&D Program of China(Grant No.2018YFE0203400)+1 种基金the Natural Science Foundation of Tianjin City(Grant No.19JCYBJC17600)the 111 Project(Grant No.B07013)。
文摘The organic-inorganic hybrid perovskite CH_(3)NH_(3)PbI_(3) has been a good candidate for many optoelectronic applications such as light-emitting diodes due to its unique properties.Optimizing the optical properties of the CH_(3)NH_(3)PbI_(3) material to improve the device performance is a hot topic.Herein,a new strategy is proposed to enhance the light emission of CH_(3)NH_(3)PbI_(3) phosphor effectively.By adding the reactant CH_(3)NH_(3)I powder in an appropriate proportion and simply grinding,the emission intensity of CH_(3)NH_(3)PbI_(3) is greatly improved.The advantages of the proposed method are swiftness,simplicity and reproducibility,and no requirement for a complex organic ligand.The mechanism of this phenomenon is revealed by x-ray diffraction,scanning electron microscopy,energy dispersive spectroscopy,photoluminescence,and temperature-dependent photoluminescence.This study offers a unique insight for optimizing the optical properties of halide perovskite materials.
