Monolithic integration of four 1.55-μm-range InGaAsP/InP distributed feedback （DFB） lasers using varied ridge width with a 4 x 1-multimode-interference （MMI） optical combiner and a semiconductor optical amplifier...Monolithic integration of four 1.55-μm-range InGaAsP/InP distributed feedback （DFB） lasers using varied ridge width with a 4 x 1-multimode-interference （MMI） optical combiner and a semiconductor optical amplifier （SOA） is demon- strated. The average output power and the threshold current are 1.8 mW and 35 mA, respectively, when the injection current of the SOA is 100 mA, with a side mode suppression ratio （SMSR） exceeding 40 dB. The four channels have a 1-nm average channel spacing and can operate separately or simultaneously.展开更多
This work focuses on the multicell multi-user distributed massive MIMO(DM-MIMO)systems,of which each user is equipped with single antenna and the base stations(BSs)consists of distributed antenna units. We first inves...This work focuses on the multicell multi-user distributed massive MIMO(DM-MIMO)systems,of which each user is equipped with single antenna and the base stations(BSs)consists of distributed antenna units. We first investigate the arbitrary BS antenna topology scenario. The derivation indicates that in this case the achievable uplink rate of an arbitrary user in central cell depends on both the number of BS's antennas and the users' access distance to each distributed antenna unit(DAU). As a result,the performance analysis based on the derivations is difficult. To overcome this issue and achieve clearer insight,we then consider a circularly distributed BS antenna array and obtain the asymptotic uplink rate of an arbitrary user by considering the asymptotic case where the number of antennas of BSs tends to infinity. It is achieved that the asymptotic uplink rate only depends on the distance from users' position to the center of reference cell. The presented numerical results show clearly that the distributed massive MIMO systems outperform the centralized ones. Moreover,it is also achieved that the interference from the adjacent cells imposes great impact on system performance. Besides this,in numerical analysis the averageasymptotic uplink rate of a user is presented,which is free of the users' position and only depends on the radius of circular antenna arrays. It is achieved the maximum average uplink rate would be achieved when the radius of circularly distributed antenna array goes to its optimization location.展开更多
In this paper,we proposed and experimentally demonstrated an 8-channel O-band distributed feedback(DFB)laser array with highly uniform 400 GHz spacing and high output power for optical input/output(I/O)technology.The ...In this paper,we proposed and experimentally demonstrated an 8-channel O-band distributed feedback(DFB)laser array with highly uniform 400 GHz spacing and high output power for optical input/output(I/O)technology.The grating phase is precisely controlled,and an equivalentπphase shift is implemented in the laser cavity via the reconstruction equivalent chirp(REC)technology.Anti-reflection(AR)and high-reflection(HR)films are coated on the front and rear facets,respectively,to enhance output power.The equivalentπphase shift is strategically placed near the HR film facet to improve the yield of the single longitudinal mode.Operating with a 400 GHz wavelength spacing,the proposed DFB laser array meets the continuous wave-wavelength division multiplexing multi-source agreement(CW-WDM MSA)specifications.The proposed DFB laser array is flip-chip bonded to a thin-film circuit with an aluminum nitride(AlN)submount to reduce the thermal resistance and enhance the output power.Compared to the p-side-up structure,the flip-chip bonding design significantly reduces junction temperature by 28%and increases maximum output power by approximately 20%.This design effectively lowers the thermal resistance of the chip and enhances its heat dissipation properties.At a bias current of 110 mA,the laser demonstrates wavelength deviations below 1.579 GHz and side-mode suppression ratios above 50 dB.The far-field divergence is measured at 25.8°×30.1°,and the Lorentzian linewidth is 3.28 MHz.Increasing the bias current to250 mA results in a laser output power exceeding 80 mW.Furthermore,the relative intensity noise(RIN)for all 8 channels is below-135.3 d B/Hz.The proposed flip-chip bonded 8-channel high-power DFB laser array demonstrates uniform wavelength spacing,high output power,and stable single longitudinal mode performance,making it a promising candidate for multiple wavelength laser sources in optical I/O technology.展开更多
Distributed pressure sensor array is a promising approach for the estimation of flight parameters for small unmanned aerial vehicles.Current flexible pressure sensor arrays are conventionally subjected to limited sens...Distributed pressure sensor array is a promising approach for the estimation of flight parameters for small unmanned aerial vehicles.Current flexible pressure sensor arrays are conventionally subjected to limited sensor resolution,poor bending flexibility,and inadequate packaging protection,resulting in insufficient precision for flight parameter estimation.Here we present a high-resolution differential pressure sensor array using a calorimetric measurement method and a multilayer polyimide bonding technique.The proposed differential pressure sensor array reaches a detection limit of 36.5 mPa over a range of 500 Pa and shows high repeatability when attached to varying curved surfaces.In addition,a superhydrophobic packaging is integrated into the sensor fabrication process,endowing it with waterproof capability.Utilizing a multilayer perceptron neural network,we demonstrated the function of the sensor array in estimating airspeeds and angle of attacks,achieving average solving errors of 0.15 m/s and 0.37°,respectively.展开更多
We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD ...We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD system. The system monitors changes in key rates and controls it is own operation automatically. The system achieves its optimal performance within three seconds of operation, which includes a sifted key rate of 5.5 kbps and a quantum bit error rate of less than 2% after an abrupt temperature variation along the 25 km quantum channel. The system also operates well over a 24 h period while completing more than 60 active optical path length compensations.展开更多
基金Project supported by the National High Technology Research and Pevelopment Program of China (Grant Nos. 2011AA010303 and 2012AA012203)the National Basic Research Program of China (Grant No. 2011CB301702)the National Natural Science Foundation of China (Grant Nos. 61021003 and 61090392)
文摘Monolithic integration of four 1.55-μm-range InGaAsP/InP distributed feedback （DFB） lasers using varied ridge width with a 4 x 1-multimode-interference （MMI） optical combiner and a semiconductor optical amplifier （SOA） is demon- strated. The average output power and the threshold current are 1.8 mW and 35 mA, respectively, when the injection current of the SOA is 100 mA, with a side mode suppression ratio （SMSR） exceeding 40 dB. The four channels have a 1-nm average channel spacing and can operate separately or simultaneously.
基金supported by the Natural Science Foundation of China under Grant 61261015 and 61561043the 973 project 2013CB329104,the Natural Science Foundation of China under Grant 61372124,61363059,and 61302100+1 种基金the projects BK2011027,the Natural Science Foundation of Gansu Province for Distinguished Young Scholars(1308RJDA007)by the Foundation Research Funds for the University of Gansu Province:‘Massive MIMO channels modeling and estimation over millimeter wave band for 5G’
文摘This work focuses on the multicell multi-user distributed massive MIMO(DM-MIMO)systems,of which each user is equipped with single antenna and the base stations(BSs)consists of distributed antenna units. We first investigate the arbitrary BS antenna topology scenario. The derivation indicates that in this case the achievable uplink rate of an arbitrary user in central cell depends on both the number of BS's antennas and the users' access distance to each distributed antenna unit(DAU). As a result,the performance analysis based on the derivations is difficult. To overcome this issue and achieve clearer insight,we then consider a circularly distributed BS antenna array and obtain the asymptotic uplink rate of an arbitrary user by considering the asymptotic case where the number of antennas of BSs tends to infinity. It is achieved that the asymptotic uplink rate only depends on the distance from users' position to the center of reference cell. The presented numerical results show clearly that the distributed massive MIMO systems outperform the centralized ones. Moreover,it is also achieved that the interference from the adjacent cells imposes great impact on system performance. Besides this,in numerical analysis the averageasymptotic uplink rate of a user is presented,which is free of the users' position and only depends on the radius of circular antenna arrays. It is achieved the maximum average uplink rate would be achieved when the radius of circularly distributed antenna array goes to its optimization location.
基金supported by the National Natural Science Foundation of China(No.62404098)the Natural Science Foundation of Jiangsu Province of China(No.BK20241196)the National Key Research and Development Program of China(Nos.2023YFB2806400,2021YFB2801902,and 2018YFB2201801)。
文摘In this paper,we proposed and experimentally demonstrated an 8-channel O-band distributed feedback(DFB)laser array with highly uniform 400 GHz spacing and high output power for optical input/output(I/O)technology.The grating phase is precisely controlled,and an equivalentπphase shift is implemented in the laser cavity via the reconstruction equivalent chirp(REC)technology.Anti-reflection(AR)and high-reflection(HR)films are coated on the front and rear facets,respectively,to enhance output power.The equivalentπphase shift is strategically placed near the HR film facet to improve the yield of the single longitudinal mode.Operating with a 400 GHz wavelength spacing,the proposed DFB laser array meets the continuous wave-wavelength division multiplexing multi-source agreement(CW-WDM MSA)specifications.The proposed DFB laser array is flip-chip bonded to a thin-film circuit with an aluminum nitride(AlN)submount to reduce the thermal resistance and enhance the output power.Compared to the p-side-up structure,the flip-chip bonding design significantly reduces junction temperature by 28%and increases maximum output power by approximately 20%.This design effectively lowers the thermal resistance of the chip and enhances its heat dissipation properties.At a bias current of 110 mA,the laser demonstrates wavelength deviations below 1.579 GHz and side-mode suppression ratios above 50 dB.The far-field divergence is measured at 25.8°×30.1°,and the Lorentzian linewidth is 3.28 MHz.Increasing the bias current to250 mA results in a laser output power exceeding 80 mW.Furthermore,the relative intensity noise(RIN)for all 8 channels is below-135.3 d B/Hz.The proposed flip-chip bonded 8-channel high-power DFB laser array demonstrates uniform wavelength spacing,high output power,and stable single longitudinal mode performance,making it a promising candidate for multiple wavelength laser sources in optical I/O technology.
基金supported financially by National Natural Science Foundation of China(Nos.T2121003,U23A20638.)the National Key Research and Development Program of China(2023YFB3208000,2023YFB3208001).
文摘Distributed pressure sensor array is a promising approach for the estimation of flight parameters for small unmanned aerial vehicles.Current flexible pressure sensor arrays are conventionally subjected to limited sensor resolution,poor bending flexibility,and inadequate packaging protection,resulting in insufficient precision for flight parameter estimation.Here we present a high-resolution differential pressure sensor array using a calorimetric measurement method and a multilayer polyimide bonding technique.The proposed differential pressure sensor array reaches a detection limit of 36.5 mPa over a range of 500 Pa and shows high repeatability when attached to varying curved surfaces.In addition,a superhydrophobic packaging is integrated into the sensor fabrication process,endowing it with waterproof capability.Utilizing a multilayer perceptron neural network,we demonstrated the function of the sensor array in estimating airspeeds and angle of attacks,achieving average solving errors of 0.15 m/s and 0.37°,respectively.
基金was supported by the ICT R&D programs of Ministry of Science, ICT and Future Planning/Institute for Information & Communications Technology Promotion (Grant No. B0101-16-1355)the Korea Institute of Science and Technology research program (Grant No. 2E27231)Korea Institute of Science and Technology-Electronics And Telecommunications Research Institute research program (Grant No. 2V05340)
文摘We develop a quantum key distribution (QKD) system with fast active optical path length compensation. A rapid and reliable active optical path length compensation scheme is proposed and applied to a plug-and-play QKD system. The system monitors changes in key rates and controls it is own operation automatically. The system achieves its optimal performance within three seconds of operation, which includes a sifted key rate of 5.5 kbps and a quantum bit error rate of less than 2% after an abrupt temperature variation along the 25 km quantum channel. The system also operates well over a 24 h period while completing more than 60 active optical path length compensations.
