In this Letter,a miniaturized receiver optical sub-assembly(ROSA) based on a low-temperature co-fired ceramic(LTCC)substrate is proposed and demonstrated.By embedding the bias circuits of the chips into the multilayer...In this Letter,a miniaturized receiver optical sub-assembly(ROSA) based on a low-temperature co-fired ceramic(LTCC)substrate is proposed and demonstrated.By embedding the bias circuits of the chips into the multilayer substrate,the space utilization of the ROSA is effectively enhanced.To eliminate parasitic parameter effects caused by the LTCC fabrication processes,an equivalent circuit model of the photodetector(PD) package network is established.The effect of the compensation capacitor at the PD chip's N-electrode on optoelectronic response characteristics is systematically analyzed.For further high-frequency performance improvement,cavity optimization is implemented through substrate excavation at the compensation capacitor location.After the cavity optimization,the S_(21) response of the ROSA demonstrates a 3dB bandwidth covering L-X bands with the average gain exceeding 1.5 dB.The designed LTCC solution can provide an excellent extension idea for the integration of multiple array elements in the airborne electronic information equipment.展开更多
The level of automation in the manufacture of recreational aluminum boats is very low. Robotized welding is rarely utilized, although it is commonly considered as the most effective way to reduce costs and increase co...The level of automation in the manufacture of recreational aluminum boats is very low. Robotized welding is rarely utilized, although it is commonly considered as the most effective way to reduce costs and increase competitiveness. A reason for the under-exploitation of robotics can be found in the construction of aluminum boats;boat models and their detailed structures are almost without exception individual pieces. A new stiffener structure for an aluminum recreational boat hull is developed in this work. Construction of the stiffener as a module allows exploitation of the advantages of modularization. The number of different parts is reduced and the structure simplified improves the applicability of robotic welding and provides benefits accruing from mass production. The same module can be used in several boat models. The modularity also makes it possible to use the same advanced robot welding fixture for a variety of boat models.展开更多
Both the 4 × 20 GHz coarse wavelength division multiplexing and LAN-WDM receiver optical sub-assemblies（ROSAs） were developed. The ROSA package was hybrid integrated with a planar lightwave circuit arrayed wave...Both the 4 × 20 GHz coarse wavelength division multiplexing and LAN-WDM receiver optical sub-assemblies（ROSAs） were developed. The ROSA package was hybrid integrated with a planar lightwave circuit arrayed waveguide grating（AWG） with 2% refractive index difference and a four-channel top-illuminated positive-intrinsicnegative photodetector（PD） array. The output waveguides of the AWG were designed in a multimode structure to provide flat-top optical spectra, and their end facet was angle-polished to form a total internal reflection interface to realize vertical coupling with a PD array. The maximum responsivity of ROSA was about 0.4 A/W, and its 3 dB bandwidth of frequency response was up to 20 GHz for each transmission lane. The hybrid integrated ROSA would be a cost-effective and easy-assembling solution for 100 Gb E data center interconnections.展开更多
基金supported by the National Key Research and Development Program of China (No.2022YFB2803200)。
文摘In this Letter,a miniaturized receiver optical sub-assembly(ROSA) based on a low-temperature co-fired ceramic(LTCC)substrate is proposed and demonstrated.By embedding the bias circuits of the chips into the multilayer substrate,the space utilization of the ROSA is effectively enhanced.To eliminate parasitic parameter effects caused by the LTCC fabrication processes,an equivalent circuit model of the photodetector(PD) package network is established.The effect of the compensation capacitor at the PD chip's N-electrode on optoelectronic response characteristics is systematically analyzed.For further high-frequency performance improvement,cavity optimization is implemented through substrate excavation at the compensation capacitor location.After the cavity optimization,the S_(21) response of the ROSA demonstrates a 3dB bandwidth covering L-X bands with the average gain exceeding 1.5 dB.The designed LTCC solution can provide an excellent extension idea for the integration of multiple array elements in the airborne electronic information equipment.
文摘The level of automation in the manufacture of recreational aluminum boats is very low. Robotized welding is rarely utilized, although it is commonly considered as the most effective way to reduce costs and increase competitiveness. A reason for the under-exploitation of robotics can be found in the construction of aluminum boats;boat models and their detailed structures are almost without exception individual pieces. A new stiffener structure for an aluminum recreational boat hull is developed in this work. Construction of the stiffener as a module allows exploitation of the advantages of modularization. The number of different parts is reduced and the structure simplified improves the applicability of robotic welding and provides benefits accruing from mass production. The same module can be used in several boat models. The modularity also makes it possible to use the same advanced robot welding fixture for a variety of boat models.
基金supported by the National High Technology Research and Development Program of China(No.2015AA016902)the National Natural Science Foundation of China(Nos.61435013 and 61405188)K.C.Wong Education Foundation
文摘Both the 4 × 20 GHz coarse wavelength division multiplexing and LAN-WDM receiver optical sub-assemblies（ROSAs） were developed. The ROSA package was hybrid integrated with a planar lightwave circuit arrayed waveguide grating（AWG） with 2% refractive index difference and a four-channel top-illuminated positive-intrinsicnegative photodetector（PD） array. The output waveguides of the AWG were designed in a multimode structure to provide flat-top optical spectra, and their end facet was angle-polished to form a total internal reflection interface to realize vertical coupling with a PD array. The maximum responsivity of ROSA was about 0.4 A/W, and its 3 dB bandwidth of frequency response was up to 20 GHz for each transmission lane. The hybrid integrated ROSA would be a cost-effective and easy-assembling solution for 100 Gb E data center interconnections.
