研究全硅基光学二极管,即在硅基芯片上实现非互易光学传输,是一项具有广泛应用前景并极具技术挑战的研究课题。采用硅基谐振结构微纳器件中非线性光学效应,完成光学非互易传输,是当前实现硅基光学二极管的重要方法。结合硅基波导中的非...研究全硅基光学二极管,即在硅基芯片上实现非互易光学传输,是一项具有广泛应用前景并极具技术挑战的研究课题。采用硅基谐振结构微纳器件中非线性光学效应,完成光学非互易传输,是当前实现硅基光学二极管的重要方法。结合硅基波导中的非线性光学效应的基本原理,以及谐振结构微纳器件的基本模型,分析了硅基谐振结构微纳器件构成的光学二极管中的非互易传输问题。仿真结果表明,依靠谐振结构中的非线性光学效应产生的器件非互易特性仅存在于特定频率,这种非互易性在谐振波长附近的一段频率区域较为明显,考虑3 d B以上的非互易传输比率区间,区间宽度累计可以达到10.6 GHz以上。分析了微环耦合系数对硅基光学二极管的非互易传输比率的影响,得出结论:精确控制波导的耦合系数,使得微环工作在接近临界耦合的状态,有助于提升器件的非互易传输比率。展开更多
An all-optical diode behavior that uses a nonlinear one-dimensional photonic crystal (NPC) with a defect Kerr medium is numerically simulated by the use of a nonlinear finite-difference time-domain (NFDTD) method.The ...An all-optical diode behavior that uses a nonlinear one-dimensional photonic crystal (NPC) with a defect Kerr medium is numerically simulated by the use of a nonlinear finite-difference time-domain (NFDTD) method.The numerical results show that for an incident pulse with appropriate intensity and temporal width,the transmittance can be several times greater in one direction of NPC than in the opposite direction at the pulse carrier frequency. This behaves like an all-optical diode and has promising applications in some areas such as optical isolation and all-optical processing.The ways to obtain low threshold of pulse field strength to realize an all-optical diode are also analyzed in detail.展开更多
Based on the commercially available avalanche photodiodes, the basic needs of gated-mode operation for single photon are discussed. Gated-mode technique based on the experimental data for detection of single photon is...Based on the commercially available avalanche photodiodes, the basic needs of gated-mode operation for single photon are discussed. Gated-mode technique based on the experimental data for detection of single photon is analyzed at communication wavelengths so that the basic operation parameters can decide properly for efficient detection of single photon. The bias voltage has related to the punch-through voltage in combining the cooling technique with synchronization to decrease the dark counts.展开更多
Optical diode behavior of asymmetric one-dimensional photonic crystal with Kerr defect is numerically investigated using nonlinear transfer matrix method. In the linear case, the intensity and the phase of transmitted...Optical diode behavior of asymmetric one-dimensional photonic crystal with Kerr defect is numerically investigated using nonlinear transfer matrix method. In the linear case, the intensity and the phase of transmitted field are the same for the forward and backward operations. In the nonlinear case, however, the transmitted intensities are much different for the two operations, which display diode characteristic. Physical origin of the anisotropic transmission lies in the different localizations in the defect layer of the two operations.展开更多
In this letter we present the results regarding the electrical and optical characterization of Geiger mode silicon avalanche photodiodes(GMAP) fabricated by silicon standard planar technology. Low dark count rates,neg...In this letter we present the results regarding the electrical and optical characterization of Geiger mode silicon avalanche photodiodes(GMAP) fabricated by silicon standard planar technology. Low dark count rates,negligible afterpulsing effects,good timing resolution and high quantum detection efficiency in all the visible range have been measured. The very good electro-optical performances of our photodiodes make them attractive for the fabrication of arrays with a large number of GMAP to be used both in the commercial and the scientific fields,as telecommunications and nuclear medical imaging.展开更多
White organic light-emitting diodes （WOLEDs） with a structure of indium-tin-oxide （ITO）/N,N＇-bis- （1-naphthyl）-N,N＇-diphenyl- （1, 1＇-biphenyl）-4,4＇-diamine （NPB）/1,2,3,4,5,6-hexakis（9,9-diethyl-9H-fluor...White organic light-emitting diodes （WOLEDs） with a structure of indium-tin-oxide （ITO）/N,N＇-bis- （1-naphthyl）-N,N＇-diphenyl- （1, 1＇-biphenyl）-4,4＇-diamine （NPB）/1,2,3,4,5,6-hexakis（9,9-diethyl-9H-fluoren-2- yl）benzene （HKEthFLYPh）/5,6,11,12-tetraphenylnaphtacene （rubrene）/tris（8-hydroxyquinoline） aluminum （Alq3）/Mg：Ag were fabricated by vacuum deposition method, in which a novel star-shaped hexafluorenyl- benzene HKEthFLYPh was used as an energy transfer layer, and an ultrathin layer of rubrene was inserted between HKEthFLYPh and Alq3 layers as a yellow light-emitting layer instead of using a time-consuming doping process. A fairly pure WOLED with Commissions Internationale De L＇Eclairage （CIE） coordinates of （0.32, 0.33） was obtained when the thickness of rubrene was 0.3 nm, and the spectrum was insensitive to the applied voltage. The device yielded a maximum luminance of 4816 cd/m2 at 18 V.展开更多
Additive manufacturing technology has been developed in Xi＇ an Jiaotong University for almost 20 years. Up to now~ it is still attracting the attentions of the researchers or manufacturers all over the world. Some in...Additive manufacturing technology has been developed in Xi＇ an Jiaotong University for almost 20 years. Up to now~ it is still attracting the attentions of the researchers or manufacturers all over the world. Some in- novative processes and frontier application research are all being conducted here to catch up with the new develop- ment of this technology. In the paper, newly developed processes, such as ultraviolet-light emitting diode （UV- LED） stereolithography, ceramic stereolithography, and direct metal forming, were described. Some results of the frontier application researches, such as indirect fabrication of ceramic casting mould, wind-tunnel-testing models, photonic crystals and metamatcrials, were also briefly reviewed.展开更多
Plastic thermo-electrochemical ceils （thermocells） involving aqueous potassium ferricyanide/ferrocyanide electrolyte have been investigated as an alternative to conventional thermoelectrics for thermal energy harves...Plastic thermo-electrochemical ceils （thermocells） involving aqueous potassium ferricyanide/ferrocyanide electrolyte have been investigated as an alternative to conventional thermoelectrics for thermal energy harvesting. Plastic thermocells that consist of all pliable materials such as polyethylene terephthalate （PET）, fabrics, and wires are flexible enough to be wearable on the human body and to be wrapped around cylindrical shapes. The performance of the thermocells is enhanced by incorporating carbon nanotubes into activated carbon textiles, due to improved charge transfer at the interface. In cold weather conditions （a surrounding temperature of 5 ℃）, the thermocell generates a short-circuit current density of 0.39 A/m2 and maximum power density of 0.46 mW/m2 from body heat （temperature of 36℃）. For practical use, we have shown that the thermocell charges up a capacitor when worn on a T-shirt by a person. We also have demonstrated that the electrical energy generated from waste pipe heat using a serial array of the thermocells and voltage converters can power a typical commercial light emitting diode （LED）.展开更多
Organolead trihalide perovskite materials have been attracting increasing attention due to their promising role in solid solar cells. Several advantages make them potential candidates for optoelectronics:(1) solution-...Organolead trihalide perovskite materials have been attracting increasing attention due to their promising role in solid solar cells. Several advantages make them potential candidates for optoelectronics:(1) solution- or/and vapor-processed preparation at low temperature;(2) tunable optical bandgap, wide absorption spectrum but narrow photoluminescence peaks;(3) long car-rier life time, large diffusion length and high charge mobility;(4) various nanostructures via tuning capping agents and sol-vents. In this review, we summarize recent attempts toward efficient LEDs based on organolead trihalide perovskite materials. The strategies of materials science, device design and interface engineering are highlighted. Recent development and future perspectives are summarized for practical perovskite light technologies.展开更多
We report a hybrid energy cell that can simultaneously or individually harvest wind, solar, and chemical energies to power some electronic devices. By utilizing the wind driven relative rotations between a polytetrafl...We report a hybrid energy cell that can simultaneously or individually harvest wind, solar, and chemical energies to power some electronic devices. By utilizing the wind driven relative rotations between a polytetrafluoroethylene film and an etched A1 film attached on two acrylic tubes, the fabricated triboelectric nanogenerator （TENG） can deliver an open-circuit voltage of about 90 V, a short-circuit current density of about 0.5 mA/m2, and a maximum power density of 16 mW/m2, which is capable of directly lighting up 20 blue light- emitting-diodes （LEDs）. By integrating a TENG, a solar cell, and an electrochemical cell, a hybrid energy cell has been fabricated to simultaneously scavenge three different types of energies. As compared with the individual energy units, the hybrid energy cell exhibited much better performance in charging a capacitor. Moreover, we also demonstrated that the hybrid energies generated can be stored in a Li-ion battery for powering a commercial wind speed sensor and a temperature sensor. This work represents significant progress toward practical applications of hybrid energy cells, providing potential solutions for simul- taneously scavenging wind, solar, and chemical energies.展开更多
文摘研究全硅基光学二极管,即在硅基芯片上实现非互易光学传输,是一项具有广泛应用前景并极具技术挑战的研究课题。采用硅基谐振结构微纳器件中非线性光学效应,完成光学非互易传输,是当前实现硅基光学二极管的重要方法。结合硅基波导中的非线性光学效应的基本原理,以及谐振结构微纳器件的基本模型,分析了硅基谐振结构微纳器件构成的光学二极管中的非互易传输问题。仿真结果表明,依靠谐振结构中的非线性光学效应产生的器件非互易特性仅存在于特定频率,这种非互易性在谐振波长附近的一段频率区域较为明显,考虑3 d B以上的非互易传输比率区间,区间宽度累计可以达到10.6 GHz以上。分析了微环耦合系数对硅基光学二极管的非互易传输比率的影响,得出结论:精确控制波导的耦合系数,使得微环工作在接近临界耦合的状态,有助于提升器件的非互易传输比率。
基金Supported by the National Natural Science Foundation of China(90201027 ,10374120)
文摘An all-optical diode behavior that uses a nonlinear one-dimensional photonic crystal (NPC) with a defect Kerr medium is numerically simulated by the use of a nonlinear finite-difference time-domain (NFDTD) method.The numerical results show that for an incident pulse with appropriate intensity and temporal width,the transmittance can be several times greater in one direction of NPC than in the opposite direction at the pulse carrier frequency. This behaves like an all-optical diode and has promising applications in some areas such as optical isolation and all-optical processing.The ways to obtain low threshold of pulse field strength to realize an all-optical diode are also analyzed in detail.
基金National"973"Project(G2001039302) Key S & T Project of Guangdong Province(2003A103405) Key S&T Project of Guangzhou City(1992-2-035-01)
文摘Based on the commercially available avalanche photodiodes, the basic needs of gated-mode operation for single photon are discussed. Gated-mode technique based on the experimental data for detection of single photon is analyzed at communication wavelengths so that the basic operation parameters can decide properly for efficient detection of single photon. The bias voltage has related to the punch-through voltage in combining the cooling technique with synchronization to decrease the dark counts.
文摘Optical diode behavior of asymmetric one-dimensional photonic crystal with Kerr defect is numerically investigated using nonlinear transfer matrix method. In the linear case, the intensity and the phase of transmitted field are the same for the forward and backward operations. In the nonlinear case, however, the transmitted intensities are much different for the two operations, which display diode characteristic. Physical origin of the anisotropic transmission lies in the different localizations in the defect layer of the two operations.
文摘In this letter we present the results regarding the electrical and optical characterization of Geiger mode silicon avalanche photodiodes(GMAP) fabricated by silicon standard planar technology. Low dark count rates,negligible afterpulsing effects,good timing resolution and high quantum detection efficiency in all the visible range have been measured. The very good electro-optical performances of our photodiodes make them attractive for the fabrication of arrays with a large number of GMAP to be used both in the commercial and the scientific fields,as telecommunications and nuclear medical imaging.
基金This work was supported by the National Natural Science Foundation of China （No.60425101 and No.20674049）, the Program for New Century Excellent Talents in University （No.NCET-06-0812）, and the Young Talent Project at University of Electronic Science and Technology of China （No.060206）.
文摘White organic light-emitting diodes （WOLEDs） with a structure of indium-tin-oxide （ITO）/N,N＇-bis- （1-naphthyl）-N,N＇-diphenyl- （1, 1＇-biphenyl）-4,4＇-diamine （NPB）/1,2,3,4,5,6-hexakis（9,9-diethyl-9H-fluoren-2- yl）benzene （HKEthFLYPh）/5,6,11,12-tetraphenylnaphtacene （rubrene）/tris（8-hydroxyquinoline） aluminum （Alq3）/Mg：Ag were fabricated by vacuum deposition method, in which a novel star-shaped hexafluorenyl- benzene HKEthFLYPh was used as an energy transfer layer, and an ultrathin layer of rubrene was inserted between HKEthFLYPh and Alq3 layers as a yellow light-emitting layer instead of using a time-consuming doping process. A fairly pure WOLED with Commissions Internationale De L＇Eclairage （CIE） coordinates of （0.32, 0.33） was obtained when the thickness of rubrene was 0.3 nm, and the spectrum was insensitive to the applied voltage. The device yielded a maximum luminance of 4816 cd/m2 at 18 V.
文摘Additive manufacturing technology has been developed in Xi＇ an Jiaotong University for almost 20 years. Up to now~ it is still attracting the attentions of the researchers or manufacturers all over the world. Some in- novative processes and frontier application research are all being conducted here to catch up with the new develop- ment of this technology. In the paper, newly developed processes, such as ultraviolet-light emitting diode （UV- LED） stereolithography, ceramic stereolithography, and direct metal forming, were described. Some results of the frontier application researches, such as indirect fabrication of ceramic casting mould, wind-tunnel-testing models, photonic crystals and metamatcrials, were also briefly reviewed.
文摘Plastic thermo-electrochemical ceils （thermocells） involving aqueous potassium ferricyanide/ferrocyanide electrolyte have been investigated as an alternative to conventional thermoelectrics for thermal energy harvesting. Plastic thermocells that consist of all pliable materials such as polyethylene terephthalate （PET）, fabrics, and wires are flexible enough to be wearable on the human body and to be wrapped around cylindrical shapes. The performance of the thermocells is enhanced by incorporating carbon nanotubes into activated carbon textiles, due to improved charge transfer at the interface. In cold weather conditions （a surrounding temperature of 5 ℃）, the thermocell generates a short-circuit current density of 0.39 A/m2 and maximum power density of 0.46 mW/m2 from body heat （temperature of 36℃）. For practical use, we have shown that the thermocell charges up a capacitor when worn on a T-shirt by a person. We also have demonstrated that the electrical energy generated from waste pipe heat using a serial array of the thermocells and voltage converters can power a typical commercial light emitting diode （LED）.
基金supported by the National Basic Research Program of China (2011CB933300)the National Natural Science Foundation of China (91333107, 51573004)the fund from Shenzhen City (CXZZ20120618162051603)
文摘Organolead trihalide perovskite materials have been attracting increasing attention due to their promising role in solid solar cells. Several advantages make them potential candidates for optoelectronics:(1) solution- or/and vapor-processed preparation at low temperature;(2) tunable optical bandgap, wide absorption spectrum but narrow photoluminescence peaks;(3) long car-rier life time, large diffusion length and high charge mobility;(4) various nanostructures via tuning capping agents and sol-vents. In this review, we summarize recent attempts toward efficient LEDs based on organolead trihalide perovskite materials. The strategies of materials science, device design and interface engineering are highlighted. Recent development and future perspectives are summarized for practical perovskite light technologies.
文摘We report a hybrid energy cell that can simultaneously or individually harvest wind, solar, and chemical energies to power some electronic devices. By utilizing the wind driven relative rotations between a polytetrafluoroethylene film and an etched A1 film attached on two acrylic tubes, the fabricated triboelectric nanogenerator （TENG） can deliver an open-circuit voltage of about 90 V, a short-circuit current density of about 0.5 mA/m2, and a maximum power density of 16 mW/m2, which is capable of directly lighting up 20 blue light- emitting-diodes （LEDs）. By integrating a TENG, a solar cell, and an electrochemical cell, a hybrid energy cell has been fabricated to simultaneously scavenge three different types of energies. As compared with the individual energy units, the hybrid energy cell exhibited much better performance in charging a capacitor. Moreover, we also demonstrated that the hybrid energies generated can be stored in a Li-ion battery for powering a commercial wind speed sensor and a temperature sensor. This work represents significant progress toward practical applications of hybrid energy cells, providing potential solutions for simul- taneously scavenging wind, solar, and chemical energies.
