The radiation-sensitive field effect transistors(RADFET)radiation dosimeter is a type of radiation detector based on the total dose effects of the p-channel metal-oxide-semiconductor(PMOS)transistor.The RADFET chip wa...The radiation-sensitive field effect transistors(RADFET)radiation dosimeter is a type of radiation detector based on the total dose effects of the p-channel metal-oxide-semiconductor(PMOS)transistor.The RADFET chip was fabricated in United Microelectronics Center 8-inch process with a six-layer photomask.The chip including two identical PMOS transistors,occupies a size of 610μm×610μm.Each PMOS has a W/L ratio of 300μm/50μm,and a 400 nm thick gate oxide,which is formed by a dry-wet-dry oxygen process.The wet oxygen-formed gate oxide with more traps can capture more holes during irradiation,thus significantly changing the PMOS threshold voltage.Pre-irradiation measurement results from ten test chips show that the initial average voltage of the PMOS is 1.961 V with a dispersion of 5.7%.The irradiation experiment is conducted in a cobalt source facility with a dose rate of 50 rad(Si)/s.During irradiation,a constant current source circuit of 10μA was connected to monitoring the shift in threshold voltage under different total dose.When the total dose is 100 krad(Si),the shift in threshold voltage was approximately 1.37 V,which demonstrates that an excellent radiation function was achieved.展开更多
As Moore’s law approaching its end,electronics is hitting its power,bandwidth,and capacity limits.Photonics is able to overcome the performance limits of electronics but lacks practical photonic register and flexible...As Moore’s law approaching its end,electronics is hitting its power,bandwidth,and capacity limits.Photonics is able to overcome the performance limits of electronics but lacks practical photonic register and flexible control.Combining electronics and photonics provides the best of both worlds and is widely regarded as an important post-Moore’s direction.For stability and dynamic operations considerations,feedback tuning of photonic devices is required.For silicon photonics,the thermooptic effect is the most frequently used tuning mechanism due to the advantages of high efficiency and low loss.However,it brings new design requirements,creating new design challenges.Emerging applications,such as optical phased array,optical switches,and optical neural networks,employ a large number of photonic devices,making PCB tuning solutions no longer suitable.Electronic-photonic-converged solutions with compact footprints will play an important role in system scalability.In this paper,we present a unified model for thermo-optic feedback tuning that can be specialized to different applications,review its recent advances,and discuss its future trends.展开更多
We present a new substrate-free bimaterial cantilever array made of SiNx and Au for an uncooled microoptomechanical infrared imaging device. Each cantilever element has an optimized deformation magnification structure...We present a new substrate-free bimaterial cantilever array made of SiNx and Au for an uncooled microoptomechanical infrared imaging device. Each cantilever element has an optimized deformation magnification structure. A 160×160 array with a 120 μm×120μm pitch is fabricated and an optical readout is used to collectively measure deflections of all microcantilevers in the array. Thermal images of room-temperature objects with higher spatial resolution have been obtained and the noise-equivalent temperature difference of the fabricated focal plane arrays is given statistically and is measured to be about 270mK.展开更多
We demonstrate a type of 2 × 2 multimode interference 3 dB coupler based on silicon-on-insulator.The fabrication tolerance was investigated by the effective index method and the guide mode method.The devices with...We demonstrate a type of 2 × 2 multimode interference 3 dB coupler based on silicon-on-insulator.The fabrication tolerance was investigated by the effective index method and the guide mode method.The devices with different lengths were fabricated and near-field output images were obtained.Tolerances to width,length and etch depth are 2,200 and 2μm,respectively.The devices show a uniform power distribution.展开更多
This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended ...This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended at the end of data bits,which eliminates the overhead of interspersing the redundancy bits at the encoder and decoder.The reliability of memory is further enhanced by the layout architecture of redundancy bits and data bits.The proposed scheme has been implemented in Verilog and synthesized using the Synopsys tools.The results reveal that the proposed method has about 19% less area penalties and 13% less power consumption comparing with the current two-dimensional error codes,and its latency of encoder and decoder is 63% less than that of Hamming codes.展开更多
A microwave monolithic integrated circuit （MMIC） C-band low noise amplifier （LNA） using 1 μm-gate composite-channel Al0.3Ga0.7N/Al0.05Ga0.95N/GaN high electron mobility transistors （CC-HEMTs） has been designed,...A microwave monolithic integrated circuit （MMIC） C-band low noise amplifier （LNA） using 1 μm-gate composite-channel Al0.3Ga0.7N/Al0.05Ga0.95N/GaN high electron mobility transistors （CC-HEMTs） has been designed, fabricated and characterized. The material structure and special channel of CC-HEMT were given and analysed. The MMIC LNA with CC-HEMT showed a noise figure of 2.4 dB, an associated gain of 12.3 dB, an input return loss of -6 dB and an output return loss of -16 dB at 6GHz. The IIP3 of the LNA is 13 dBm at 6 GHz. The LNA with 1 μm ×100 μm device showed very high-dynamic range with decent gain and noise figure.展开更多
Scheduling algorithm always plays an important role in the spatial architecture for the contradiction between the finite network bandwidth and the abundant execution resources. This article provides a simple method to...Scheduling algorithm always plays an important role in the spatial architecture for the contradiction between the finite network bandwidth and the abundant execution resources. This article provides a simple method to solve the contention for network resource in one of the spatial architecture, i.e. the tera-op, reliable, intelligently adaptive processing system(TRIPS) processor. The method improves the performance of network by increasing the bypass bandwidth which can transmit the data in the internal of every execution unit, and converting the proportion of remote communication by the deep scheduling algorithm. The deeply optimized algorithm is realized to verify the validity of the method, and the performance increase 9% for floating point spec2000 benchmark is got.展开更多
Low energy consumption is one of the main challenges for wireless video transmission on battery limited devices. The energy invested at the lower layers of the protocol stack involved in data communication, such as li...Low energy consumption is one of the main challenges for wireless video transmission on battery limited devices. The energy invested at the lower layers of the protocol stack involved in data communication, such as link and physical layer, represent an important part of the total energy consumption. This communication energy highly depends on the channel conditions and on the transmission data rate. Traditionally, video coding is unaware of varying channel conditions. In this paper, we propose a cross-layer approach in which the rate control mechanism of the video codec becomes channel-aware and steers the instantaneous output rate according to the channel conditions to reduce the communication energy. Our results show that energy savings of up to30% can be obtained with a reduction of barely 0.1 dB on the average video quality. The impact of feedback delays is shown to be small. In addition, this adaptive mechanism has low complexity, which makes it suitable for real-time applications.展开更多
The influence of silicon slice flatness on bonding technology and the relation between a foreign particle and resulting bubble are quantitatively presented by the elastic theory. It is demonstrated experimentally by X...The influence of silicon slice flatness on bonding technology and the relation between a foreign particle and resulting bubble are quantitatively presented by the elastic theory. It is demonstrated experimentally by X-ray double crystal diffractometry and infrared imager.展开更多
A unified model of low temperature current gain of polysilicon emitter bipolar transistors based on effective recombination method is presented, incorporating band-gap narrowing, carrier freezing-out, tunneling of hol...A unified model of low temperature current gain of polysilicon emitter bipolar transistors based on effective recombination method is presented, incorporating band-gap narrowing, carrier freezing-out, tunneling of holes through polysilicon/silicon interface oxide layer and reduced mobility mechanism in polysilicon. The modeling results based on this model are in good agreement with experimental data.展开更多
The residual mechanical stress in SiO<sub>2</sub> films results in the degradation of mobilitiesin MOSFETs. Based on the edge force approximation in SiO<sub>2</sub> films, the stress field in M...The residual mechanical stress in SiO<sub>2</sub> films results in the degradation of mobilitiesin MOSFETs. Based on the edge force approximation in SiO<sub>2</sub> films, the stress field in MOS devicesis calculated. The results here are in agreement with those measured by the Raman spectrummethod.展开更多
The rapidly developing perovskite solar cells(PSCs) provide a new and promising choice of thin film solar cells due to their attractive attributes.Among the commercialized thin film solar cells,CuInGaSe(CIGS)cells dem...The rapidly developing perovskite solar cells(PSCs) provide a new and promising choice of thin film solar cells due to their attractive attributes.Among the commercialized thin film solar cells,CuInGaSe(CIGS)cells demonstrate higher efficiency than amorphous Si photovoltaic devices and lower toxicity than CdTe cells.Therefore,a wide variety of studies have been conducted on them.Here,we elucidate CIGS materials and perovskites as absorber in thin film solar cells in terms of structure and optoelectronic properties.Furthermore,a comparison of PSCs and commercialized CIGS cells is made from the point of view of fabrication process,stability,and toxicity.In addition,the integration of CIGS devices and PSCs is elaborated based on tandem architecture.Finally,prospects for the advancement of CIGS cells and PSCs are discussed.展开更多
Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is propose...Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is proposed in this paper. The new topology can correspond to a 90 plus percent of power converting. So,a novel topology of an state of art integrated circuit, which can be used as power management circuit, has been designed based on the above new topology. A simulator which is specifically suitable for the power controller has been founded in this work and it has been used for the simulation of the novel architecture and the proposed integrated circuit.展开更多
A programmable photonic solver for quadratic unconstrained binary optimization(QUBO)problems is demonstrated with a hybrid optoelectronic scheme,which consists of a photonic chip and an electronic driving board.The ph...A programmable photonic solver for quadratic unconstrained binary optimization(QUBO)problems is demonstrated with a hybrid optoelectronic scheme,which consists of a photonic chip and an electronic driving board.The photonic chip is employed to perform the optical vector-matrix multiplication(OVMM)to calculate the cost function of the QUBO problem,while the electronic processor runs the heuristic algorithm to search for the optimal solution.Due to the parallel and low-latency propagation of lightwaves,the calculation of the cost function can be accelerated.The photonic chip was fabricated on the silicon on insulator(SOI)substrate and integrated 16 high-speed electro-optic modulators,88 thermo-optic phase shifters,and 16 balanced photodetectors.The computing speed of the photonic chip is 1.66 TFLOP/s.As a proof of principle,two randomly generated 16-dimensional QUBO problems are solved with high successful probabilities.These results present the potential of fast-solving optimization problems with integrated photonic systems.展开更多
Programmable photonic integrated circuits(PICs)have emerged as a promising platform for analog signal processing.Programmable PICs,as versatile photonic integrated platforms,can realize a wide range of functionalities...Programmable photonic integrated circuits(PICs)have emerged as a promising platform for analog signal processing.Programmable PICs,as versatile photonic integrated platforms,can realize a wide range of functionalities through software control.However,a significant challenge lies in the efficient management of a large number of programmable units,which is essential for the realization of complex photonic applications.In this paper,we propose an innovative approach using Ising-model-based intelligent computing to enable dynamic reconfiguration of large-scale programmable PICs.In the theoretical framework,we model the Mach–Zehnder interferometer(MZI)fundamental units within programmable PICs as spin qubits with binary decision variables,forming the basis for the Ising model.The function of programmable PIC implementation can be reformulated as a path-planning problem,which is then addressed using the Ising model.The states of MZI units are accordingly determined as the Ising model evolves toward the lowest Ising energy.This method facilitates the simultaneous configuration of a vast number of MZI unit states,unlocking the full potential of programmable PICs for high-speed,large-scale analog signal processing.To demonstrate the efficacy of our approach,we present two distinct photonic systems:a 4×4 wavelength routing system for balanced transmission of four-channel NRZ/PAM-4 signals and an optical neural network that achieves a recognition accuracy of 96.2%.Additionally,our system demonstrates a reconfiguration speed of 30 ms and scalability to a 56×56 port network with 2000 MZI units.This work provides a groundbreaking theoretical framework and paves the way for scalable,high-speed analog signal processing in large-scale programmable PICs.展开更多
Heavy ion-induced single event upsets(SEUs)of static random access memory(SRAM), integrated with three-dimensional integrated circuit technology, are evaluated using a Monte Carlo simulation method based on the Geant4...Heavy ion-induced single event upsets(SEUs)of static random access memory(SRAM), integrated with three-dimensional integrated circuit technology, are evaluated using a Monte Carlo simulation method based on the Geant4 simulation toolkit. The SEU cross sections and multiple cell upset(MCU) susceptibility of 3D SRAM are explored using different types and energies of heavy ions.In the simulations, the sensitivities of different dies of 3D SRAM show noticeable discrepancies for low linear energy transfers(LETs). The average percentage of MCUs of 3D SRAM increases from 17.2 to 32.95%, followed by the energy of ^(209)Bi decreasing from 71.77 to 38.28 MeV/u. For a specific LET, the percentage of MCUs presents a notable difference between the face-to-face and back-toface structures. In the back-to-face structure, the percentage of MCUs increases with a deeper die, compared with the face-to-face structure. The simulation method and process are verified by comparing the SEU cross sections of planar SRAM with experimental data. The upset cross sections of the planar process and 3D integrated SRAM are analyzed. The results demonstrate that the 3D SRAM sensitivity is not greater than that of the planar SRAM. The 3D process technology has the potential to be applied to the aerospace and military fields.展开更多
In this paper,ZnZnFe_(2)O_(4) nanorods were prepared using Zn/Fe metal organic framework(MOF)as precursors,and ZnZnFe_(2)O_(4)/reduced graphene oxide(rGO)was prepared by hydrothermal method.The morphology and composit...In this paper,ZnZnFe_(2)O_(4) nanorods were prepared using Zn/Fe metal organic framework(MOF)as precursors,and ZnZnFe_(2)O_(4)/reduced graphene oxide(rGO)was prepared by hydrothermal method.The morphology and composition of the ZnZnFe_(2)O_(4)/rGO nanocomposite were characterized,and the results showed that the MOF-derived ZnZnFe_(2)O_(4) nanorods are uniformly modified on the surface of rGO.The ZnZnFe_(2)O_(4)/rGO nanocomposite exhibits better SO_(2) gas sensing performance than the single ZnZnFe_(2)O_(4) nanorods at room temperature.The sensing characteristics of single ZnZnFe_(2)O_(4) film sensor,single rGO film sensor and ZnZnFe_(2)O_(4)/rGO composite film sensor at SO_(2)gas concentration(1×10^(-6)-100×10^(-6))were tested.The response of ZnZnFe_(2)O_(4)/rGO composite sensor can reach 18.32%at room temperature.Compared with single ZnZnFe_(2)O_(4) and rGO film sensors,the ZnZnFe_(2)O_(4)/rGO composite sensor has better transient response,good sensitivity and selectivity.In this work,the improvement of the sensor performance is not only due to the p-n heterostructure between ZnZnFe_(2)O_(4) nanorods and rGO nanosheets,but also to the excellent electrical properties of rGO.It provides a new idea for the detection of SO_(2) at room temperature.展开更多
Blue-green electroluminescence has been observed in free-standing diamond films which were deposited by microwave plasma assisted CVD on silicon substrates.The electroluminescence device is driven by a 60 Hz power sup...Blue-green electroluminescence has been observed in free-standing diamond films which were deposited by microwave plasma assisted CVD on silicon substrates.The electroluminescence device is driven by a 60 Hz power supply.The threshold voltage was about 112 V peak-to-peak.The electroluminescence spectrum at room temperature,showed a blue-green band with the peak centered at 485nm suggesting band A type emission.Electroluminescence was also observed at 77K.展开更多
文摘The radiation-sensitive field effect transistors(RADFET)radiation dosimeter is a type of radiation detector based on the total dose effects of the p-channel metal-oxide-semiconductor(PMOS)transistor.The RADFET chip was fabricated in United Microelectronics Center 8-inch process with a six-layer photomask.The chip including two identical PMOS transistors,occupies a size of 610μm×610μm.Each PMOS has a W/L ratio of 300μm/50μm,and a 400 nm thick gate oxide,which is formed by a dry-wet-dry oxygen process.The wet oxygen-formed gate oxide with more traps can capture more holes during irradiation,thus significantly changing the PMOS threshold voltage.Pre-irradiation measurement results from ten test chips show that the initial average voltage of the PMOS is 1.961 V with a dispersion of 5.7%.The irradiation experiment is conducted in a cobalt source facility with a dose rate of 50 rad(Si)/s.During irradiation,a constant current source circuit of 10μA was connected to monitoring the shift in threshold voltage under different total dose.When the total dose is 100 krad(Si),the shift in threshold voltage was approximately 1.37 V,which demonstrates that an excellent radiation function was achieved.
基金This work was supported by the National Key Research and Development Program of China(No.2018YFA0704400).
文摘As Moore’s law approaching its end,electronics is hitting its power,bandwidth,and capacity limits.Photonics is able to overcome the performance limits of electronics but lacks practical photonic register and flexible control.Combining electronics and photonics provides the best of both worlds and is widely regarded as an important post-Moore’s direction.For stability and dynamic operations considerations,feedback tuning of photonic devices is required.For silicon photonics,the thermooptic effect is the most frequently used tuning mechanism due to the advantages of high efficiency and low loss.However,it brings new design requirements,creating new design challenges.Emerging applications,such as optical phased array,optical switches,and optical neural networks,employ a large number of photonic devices,making PCB tuning solutions no longer suitable.Electronic-photonic-converged solutions with compact footprints will play an important role in system scalability.In this paper,we present a unified model for thermo-optic feedback tuning that can be specialized to different applications,review its recent advances,and discuss its future trends.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10472111, 10732080 and 10627201, and the National Basic Research Programme of China under Grant No 2006CB300404.
文摘We present a new substrate-free bimaterial cantilever array made of SiNx and Au for an uncooled microoptomechanical infrared imaging device. Each cantilever element has an optimized deformation magnification structure. A 160×160 array with a 120 μm×120μm pitch is fabricated and an optical readout is used to collectively measure deflections of all microcantilevers in the array. Thermal images of room-temperature objects with higher spatial resolution have been obtained and the noise-equivalent temperature difference of the fabricated focal plane arrays is given statistically and is measured to be about 270mK.
基金Supported by the National Natural Science Foundation of China under Grant Nos.69896260 and 69990540。
文摘We demonstrate a type of 2 × 2 multimode interference 3 dB coupler based on silicon-on-insulator.The fabrication tolerance was investigated by the effective index method and the guide mode method.The devices with different lengths were fabricated and near-field output images were obtained.Tolerances to width,length and etch depth are 2,200 and 2μm,respectively.The devices show a uniform power distribution.
基金Sponsored by the Opening Project of National Key Laboratory of Science and Technology on Reliability PhysicsApplication Technology of Electrical Component(Grant No.ZHD200903)
文摘This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost overhead.The redundancy bits of improved Hamming codes will be appended at the end of data bits,which eliminates the overhead of interspersing the redundancy bits at the encoder and decoder.The reliability of memory is further enhanced by the layout architecture of redundancy bits and data bits.The proposed scheme has been implemented in Verilog and synthesized using the Synopsys tools.The results reveal that the proposed method has about 19% less area penalties and 13% less power consumption comparing with the current two-dimensional error codes,and its latency of encoder and decoder is 63% less than that of Hamming codes.
基金Project supported by the National Natural Science Foundation of China （Grant No 60476035）.
文摘A microwave monolithic integrated circuit （MMIC） C-band low noise amplifier （LNA） using 1 μm-gate composite-channel Al0.3Ga0.7N/Al0.05Ga0.95N/GaN high electron mobility transistors （CC-HEMTs） has been designed, fabricated and characterized. The material structure and special channel of CC-HEMT were given and analysed. The MMIC LNA with CC-HEMT showed a noise figure of 2.4 dB, an associated gain of 12.3 dB, an input return loss of -6 dB and an output return loss of -16 dB at 6GHz. The IIP3 of the LNA is 13 dBm at 6 GHz. The LNA with 1 μm ×100 μm device showed very high-dynamic range with decent gain and noise figure.
基金Acknowledgments This work is supported by the open research fund of Key Laboratory of MEMS of Ministry of Education, Southeast University, Natural Science Foundation of China （No.60876078）.
文摘Scheduling algorithm always plays an important role in the spatial architecture for the contradiction between the finite network bandwidth and the abundant execution resources. This article provides a simple method to solve the contention for network resource in one of the spatial architecture, i.e. the tera-op, reliable, intelligently adaptive processing system(TRIPS) processor. The method improves the performance of network by increasing the bypass bandwidth which can transmit the data in the internal of every execution unit, and converting the proportion of remote communication by the deep scheduling algorithm. The deeply optimized algorithm is realized to verify the validity of the method, and the performance increase 9% for floating point spec2000 benchmark is got.
基金Project (No. IST-2004-004042) supported by European Project BETSY (BEing on Time Saves energY)
文摘Low energy consumption is one of the main challenges for wireless video transmission on battery limited devices. The energy invested at the lower layers of the protocol stack involved in data communication, such as link and physical layer, represent an important part of the total energy consumption. This communication energy highly depends on the channel conditions and on the transmission data rate. Traditionally, video coding is unaware of varying channel conditions. In this paper, we propose a cross-layer approach in which the rate control mechanism of the video codec becomes channel-aware and steers the instantaneous output rate according to the channel conditions to reduce the communication energy. Our results show that energy savings of up to30% can be obtained with a reduction of barely 0.1 dB on the average video quality. The impact of feedback delays is shown to be small. In addition, this adaptive mechanism has low complexity, which makes it suitable for real-time applications.
文摘The influence of silicon slice flatness on bonding technology and the relation between a foreign particle and resulting bubble are quantitatively presented by the elastic theory. It is demonstrated experimentally by X-ray double crystal diffractometry and infrared imager.
基金Supported by National Natural Science Foundation of China
文摘A unified model of low temperature current gain of polysilicon emitter bipolar transistors based on effective recombination method is presented, incorporating band-gap narrowing, carrier freezing-out, tunneling of holes through polysilicon/silicon interface oxide layer and reduced mobility mechanism in polysilicon. The modeling results based on this model are in good agreement with experimental data.
文摘The residual mechanical stress in SiO<sub>2</sub> films results in the degradation of mobilitiesin MOSFETs. Based on the edge force approximation in SiO<sub>2</sub> films, the stress field in MOS devicesis calculated. The results here are in agreement with those measured by the Raman spectrummethod.
基金supported by the NSF NNCI grant ECCS-2025227 at the Texas Nanofabrication Facility。
文摘The rapidly developing perovskite solar cells(PSCs) provide a new and promising choice of thin film solar cells due to their attractive attributes.Among the commercialized thin film solar cells,CuInGaSe(CIGS)cells demonstrate higher efficiency than amorphous Si photovoltaic devices and lower toxicity than CdTe cells.Therefore,a wide variety of studies have been conducted on them.Here,we elucidate CIGS materials and perovskites as absorber in thin film solar cells in terms of structure and optoelectronic properties.Furthermore,a comparison of PSCs and commercialized CIGS cells is made from the point of view of fabrication process,stability,and toxicity.In addition,the integration of CIGS devices and PSCs is elaborated based on tandem architecture.Finally,prospects for the advancement of CIGS cells and PSCs are discussed.
基金supported by Program for New Century Excellent Talents in University(NCET)(2008)Funding Project for Academic Human Resources Development in Institutions of Higher Learning Under the Jurisdiction of Beijing Municipality+1 种基金 (PHR(IHLB)) and Beijing Novel Research Star(2005B01)Ministry of Beijing Science and Technology
文摘Recently, resonant AC/DC converter has been accepted by the industry. However, the efficiency will be decreased at light load. So, a novel topology with critical controlling mode combined with resonant ones is proposed in this paper. The new topology can correspond to a 90 plus percent of power converting. So,a novel topology of an state of art integrated circuit, which can be used as power management circuit, has been designed based on the above new topology. A simulator which is specifically suitable for the power controller has been founded in this work and it has been used for the simulation of the novel architecture and the proposed integrated circuit.
基金the National Key Research and Development Program of China(2023YFB2806703)the National Natural Science Foundation of China(Grant No.U22A6004,92365210)is greatly acknowledgedsupported by Beijing National Research Center For Information Science And Technology,Frontier Science Center for Quantum Information,Beijing Academy of Quantum Information Sciences,Tsinghua University Initiative Scientific Research Program.
文摘A programmable photonic solver for quadratic unconstrained binary optimization(QUBO)problems is demonstrated with a hybrid optoelectronic scheme,which consists of a photonic chip and an electronic driving board.The photonic chip is employed to perform the optical vector-matrix multiplication(OVMM)to calculate the cost function of the QUBO problem,while the electronic processor runs the heuristic algorithm to search for the optimal solution.Due to the parallel and low-latency propagation of lightwaves,the calculation of the cost function can be accelerated.The photonic chip was fabricated on the silicon on insulator(SOI)substrate and integrated 16 high-speed electro-optic modulators,88 thermo-optic phase shifters,and 16 balanced photodetectors.The computing speed of the photonic chip is 1.66 TFLOP/s.As a proof of principle,two randomly generated 16-dimensional QUBO problems are solved with high successful probabilities.These results present the potential of fast-solving optimization problems with integrated photonic systems.
基金Youth Innovation Promotion Association of the Chinese Academy of Sciences(2022111)International Partnership Program of Chinese Academy of Sciences(100GJHZ2022028GC)+1 种基金Natural Science Foundation of Beijing Municipality(Z210005)National Natural Science Foundation of China(62135014,62235011)。
文摘Programmable photonic integrated circuits(PICs)have emerged as a promising platform for analog signal processing.Programmable PICs,as versatile photonic integrated platforms,can realize a wide range of functionalities through software control.However,a significant challenge lies in the efficient management of a large number of programmable units,which is essential for the realization of complex photonic applications.In this paper,we propose an innovative approach using Ising-model-based intelligent computing to enable dynamic reconfiguration of large-scale programmable PICs.In the theoretical framework,we model the Mach–Zehnder interferometer(MZI)fundamental units within programmable PICs as spin qubits with binary decision variables,forming the basis for the Ising model.The function of programmable PIC implementation can be reformulated as a path-planning problem,which is then addressed using the Ising model.The states of MZI units are accordingly determined as the Ising model evolves toward the lowest Ising energy.This method facilitates the simultaneous configuration of a vast number of MZI unit states,unlocking the full potential of programmable PICs for high-speed,large-scale analog signal processing.To demonstrate the efficacy of our approach,we present two distinct photonic systems:a 4×4 wavelength routing system for balanced transmission of four-channel NRZ/PAM-4 signals and an optical neural network that achieves a recognition accuracy of 96.2%.Additionally,our system demonstrates a reconfiguration speed of 30 ms and scalability to a 56×56 port network with 2000 MZI units.This work provides a groundbreaking theoretical framework and paves the way for scalable,high-speed analog signal processing in large-scale programmable PICs.
基金supported by the Fundamental Research Funds for the Central Universities(No.HIT.KISTP.201404)Harbin science and innovation research special fund(No.2015RAXXJ003)Special fund for development of Shenzhen strategic emerging industries(No.JCYJ20150625142543456)
文摘Heavy ion-induced single event upsets(SEUs)of static random access memory(SRAM), integrated with three-dimensional integrated circuit technology, are evaluated using a Monte Carlo simulation method based on the Geant4 simulation toolkit. The SEU cross sections and multiple cell upset(MCU) susceptibility of 3D SRAM are explored using different types and energies of heavy ions.In the simulations, the sensitivities of different dies of 3D SRAM show noticeable discrepancies for low linear energy transfers(LETs). The average percentage of MCUs of 3D SRAM increases from 17.2 to 32.95%, followed by the energy of ^(209)Bi decreasing from 71.77 to 38.28 MeV/u. For a specific LET, the percentage of MCUs presents a notable difference between the face-to-face and back-toface structures. In the back-to-face structure, the percentage of MCUs increases with a deeper die, compared with the face-to-face structure. The simulation method and process are verified by comparing the SEU cross sections of planar SRAM with experimental data. The upset cross sections of the planar process and 3D integrated SRAM are analyzed. The results demonstrate that the 3D SRAM sensitivity is not greater than that of the planar SRAM. The 3D process technology has the potential to be applied to the aerospace and military fields.
文摘In this paper,ZnZnFe_(2)O_(4) nanorods were prepared using Zn/Fe metal organic framework(MOF)as precursors,and ZnZnFe_(2)O_(4)/reduced graphene oxide(rGO)was prepared by hydrothermal method.The morphology and composition of the ZnZnFe_(2)O_(4)/rGO nanocomposite were characterized,and the results showed that the MOF-derived ZnZnFe_(2)O_(4) nanorods are uniformly modified on the surface of rGO.The ZnZnFe_(2)O_(4)/rGO nanocomposite exhibits better SO_(2) gas sensing performance than the single ZnZnFe_(2)O_(4) nanorods at room temperature.The sensing characteristics of single ZnZnFe_(2)O_(4) film sensor,single rGO film sensor and ZnZnFe_(2)O_(4)/rGO composite film sensor at SO_(2)gas concentration(1×10^(-6)-100×10^(-6))were tested.The response of ZnZnFe_(2)O_(4)/rGO composite sensor can reach 18.32%at room temperature.Compared with single ZnZnFe_(2)O_(4) and rGO film sensors,the ZnZnFe_(2)O_(4)/rGO composite sensor has better transient response,good sensitivity and selectivity.In this work,the improvement of the sensor performance is not only due to the p-n heterostructure between ZnZnFe_(2)O_(4) nanorods and rGO nanosheets,but also to the excellent electrical properties of rGO.It provides a new idea for the detection of SO_(2) at room temperature.
基金the National Natural Science Foundation of China,and the Natural Science Foundation of He'nan province.
文摘Blue-green electroluminescence has been observed in free-standing diamond films which were deposited by microwave plasma assisted CVD on silicon substrates.The electroluminescence device is driven by a 60 Hz power supply.The threshold voltage was about 112 V peak-to-peak.The electroluminescence spectrum at room temperature,showed a blue-green band with the peak centered at 485nm suggesting band A type emission.Electroluminescence was also observed at 77K.
