In this Letter,we propose and experimentally demonstrate,to the best of our knowledge,a novel compact power-equalized multi-wavelength laser(MWL)source for optical I/O technology.This multi-wavelength distributed feed...In this Letter,we propose and experimentally demonstrate,to the best of our knowledge,a novel compact power-equalized multi-wavelength laser(MWL)source for optical I/O technology.This multi-wavelength distributed feedback(DFB)laser array is used to achieve simultaneous emission of multiple wavelengths with balanced output power and stable single-mode operation.The reconstruction equivalent chirp technique is used to design and fabricate theπ-phase shifted DFB laser array to achieve precise wavelength spacing.The power equalizers(PEs)are monolithically integrated in front of the laser unit to equalize the output power.The experimental results show that the wavelength spacing of the proposed eight-channel MWL is 100 G±4.38 G,and the maximum deviation of the intensity(MDOI)is 1.00 dB under a 25℃working environment.Compared with the traditional MWL structure,the wavelength spacing error is reduced from 0.32 to 0.035 nm,and the MODI is reduced from 3.8 to 1.0 dB.The output power exceeds 25 mW when the current injected into the semiconductor optical amplifier(SOA)is 150 mA.Besides,the relative intensity noise(RIN)of all wavelengths is below-138 dB/Hz,and clear 25 Gb/s non-return-to-zero(NRZ)eye diagrams are obtained for the eight wavelengths with the external lithium-niobate Mach-Zehnder modulator.The superior performance of the proposed MWL makes it a promising method for low-bit-error optical I/O links and high-density chip interconnection systems.展开更多
In general, there is a demand for real-time processing of mass quantity remote sensing images. However, the task is not only data-intensive but also computating-intensive. Distributed processing is a hot topic in remo...In general, there is a demand for real-time processing of mass quantity remote sensing images. However, the task is not only data-intensive but also computating-intensive. Distributed processing is a hot topic in remote sensing processing and image deblurring is also one of the most important needs. In order to satisfy the demand for quick proc- essing and deblurring of mass quantity satellite images, we developed a distributed, grid computation-based platform as well as a corresponding middleware for grid computation. Both a constrained power spectrum equalization algorithm and effective block processing measures, which can avoid boundary effect, were applied during the processing. The re- sult is satisfactory since computation efficiency and visual effect were greatly improved. It can be concluded that the technology of spatial information grids is effective for mass quantity remote sensing image processing.展开更多
Cooperative relaying has played an important role in rapid evolution of wireless communications.The cooperative performance strongly depends on the selected relays.In this paper,we concentrate on relay selection in am...Cooperative relaying has played an important role in rapid evolution of wireless communications.The cooperative performance strongly depends on the selected relays.In this paper,we concentrate on relay selection in amplify-and-forward(AF)cooperative communication system,and an optimal multi-relay selection scheme is put forward to minimize the average symbol error rate(SER)of the system.Firstly,for the minimum average SER,on the basis of the statistic channel information,we define a parameter named equivalent channel gain which describes the channel status of two phases in the cooperative process.Then,under the constraint of equal power allocation,an optimal relay selection scheme is proposed in ascending order of equivalent channel gain(ECG).The scheme implies that the suitable number of relay nodes should be selected under the different signal-to-noise ratio(SNR)ranges to minimize the average SER.Computer simulation results show that the average SER rate of the proposed scheme is lower than these of the other schemes.展开更多
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 Letter,we propose and experimentally demonstrate,to the best of our knowledge,a novel compact power-equalized multi-wavelength laser(MWL)source for optical I/O technology.This multi-wavelength distributed feedback(DFB)laser array is used to achieve simultaneous emission of multiple wavelengths with balanced output power and stable single-mode operation.The reconstruction equivalent chirp technique is used to design and fabricate theπ-phase shifted DFB laser array to achieve precise wavelength spacing.The power equalizers(PEs)are monolithically integrated in front of the laser unit to equalize the output power.The experimental results show that the wavelength spacing of the proposed eight-channel MWL is 100 G±4.38 G,and the maximum deviation of the intensity(MDOI)is 1.00 dB under a 25℃working environment.Compared with the traditional MWL structure,the wavelength spacing error is reduced from 0.32 to 0.035 nm,and the MODI is reduced from 3.8 to 1.0 dB.The output power exceeds 25 mW when the current injected into the semiconductor optical amplifier(SOA)is 150 mA.Besides,the relative intensity noise(RIN)of all wavelengths is below-138 dB/Hz,and clear 25 Gb/s non-return-to-zero(NRZ)eye diagrams are obtained for the eight wavelengths with the external lithium-niobate Mach-Zehnder modulator.The superior performance of the proposed MWL makes it a promising method for low-bit-error optical I/O links and high-density chip interconnection systems.
基金Project 2003AA135010 supported by the National High Technology Research and Development Program of China
文摘In general, there is a demand for real-time processing of mass quantity remote sensing images. However, the task is not only data-intensive but also computating-intensive. Distributed processing is a hot topic in remote sensing processing and image deblurring is also one of the most important needs. In order to satisfy the demand for quick proc- essing and deblurring of mass quantity satellite images, we developed a distributed, grid computation-based platform as well as a corresponding middleware for grid computation. Both a constrained power spectrum equalization algorithm and effective block processing measures, which can avoid boundary effect, were applied during the processing. The re- sult is satisfactory since computation efficiency and visual effect were greatly improved. It can be concluded that the technology of spatial information grids is effective for mass quantity remote sensing image processing.
基金National Natural Science Foundation of China(No.61072088,No.61101113and No.61201198)Beijing Natural Science Foundation of China(No.4132019,No.4132015and No.4132007)Doctorate Subject Foundation of the Ministry of Education(No.20111103120017)
文摘Cooperative relaying has played an important role in rapid evolution of wireless communications.The cooperative performance strongly depends on the selected relays.In this paper,we concentrate on relay selection in amplify-and-forward(AF)cooperative communication system,and an optimal multi-relay selection scheme is put forward to minimize the average symbol error rate(SER)of the system.Firstly,for the minimum average SER,on the basis of the statistic channel information,we define a parameter named equivalent channel gain which describes the channel status of two phases in the cooperative process.Then,under the constraint of equal power allocation,an optimal relay selection scheme is proposed in ascending order of equivalent channel gain(ECG).The scheme implies that the suitable number of relay nodes should be selected under the different signal-to-noise ratio(SNR)ranges to minimize the average SER.Computer simulation results show that the average SER rate of the proposed scheme is lower than these of the other schemes.
