To address the challenge of achieving stable in-phase coherent optical field in high-power laser arrays,we propose a novel dual Talbot diffraction coupling method that combines the on-chip self-injection effect with a...To address the challenge of achieving stable in-phase coherent optical field in high-power laser arrays,we propose a novel dual Talbot diffraction coupling method that combines the on-chip self-injection effect with a mixed-resonant cavity diode laser array(MDLA).The designed MDLA incorporates two types of resonant cavities and an integrated external fractional Talbot cavity to compensate for in-phase mode phase delays.Numerical simulations demonstrate that the nearfield optical pattern can be self-imaged via self-organized phase-locking,while the far-field optical pattern of in-phase mode can be coherently enhanced and modulated to exhibit a single-lobe pattern successfully.Furthermore,this method could inherently provide strong optical coupling and overcome the limited scalability of the weakly-coupled laser arrays.Ultimately,by leveraging self-organized phase-locking and Talbot-induced mode discrimination,our approach offers a robust platform for realizing high-power coherent laser sources with scalable integration potential.展开更多
The room-temperature(RT)bonding mechanisms of Ga As/Si O_(2)/Si and Ga As/Si heterointerfaces fabricated by surface-activated bonding(SAB)are investigated using a focused ion beam(FIB)system,cross-sectional scanning t...The room-temperature(RT)bonding mechanisms of Ga As/Si O_(2)/Si and Ga As/Si heterointerfaces fabricated by surface-activated bonding(SAB)are investigated using a focused ion beam(FIB)system,cross-sectional scanning transmission electron microscopy(TEM),energy dispersive x-ray spectroscopy(EDX)and scanning acoustic microscopy(SAM).According to the element distribution detected by TEM and EDX,it is found that an intermixing process occurs among different atoms at the heterointerface during the RT bonding process following the surface-activation treatment.The diffusion of atoms at the interface is enhanced by the point defects introduced by the process of surface activation.We can confirm that through the point defects,a strong heterointerface can be created at RT.The measured bonding energies of Ga As/Si O_(2)/Si and Ga As/Si wafers are 0.7 J/m^(2)and 0.6 J/m^(2).The surface-activation process can not only remove surface oxides and generate dangling bonds,but also enhance the atomic diffusivity at the interface.展开更多
High-quality bonding of 4-inch GaAs and Si is achieved using plasma-activated bonding technology.The influence of Ar plasma activation on surface morphology is discussed.When the annealing temperature is 300℃,the bon...High-quality bonding of 4-inch GaAs and Si is achieved using plasma-activated bonding technology.The influence of Ar plasma activation on surface morphology is discussed.When the annealing temperature is 300℃,the bonding strength reaches a maximum of 6.2 MPa.In addition,a thermal stress model for GaAs/Si wafers is established based on finite element analysis to obtain the distribution of equivalent stress and deformation variables at different temperatures.The shape varia-tion of the wafer is directly proportional to the annealing temperature.At an annealing temperature of 400℃,the maximum protrusion of 4 inches GaAs/Si wafers is 3.6 mm.The interface of GaAs/Si wafers is observed to be dense and defect-free using a transmission electron microscope.The characterization of interface elements by X-ray energy dispersion spectroscopy indi-cates that the elements at the interface undergo mutual diffusion,which is beneficial for improving the bonding strength of the interface.There is an amorphous transition layer with a thickness of about 5 nm at the bonding interface.The preparation of Si-based GaAs heterojunctions can enrich the types of materials required for the development of integrated circuits,improve the performance of materials and devices,and promote the development of microelectronics technology.展开更多
In this work,the surface morphology and internal defect evolution process of GaAs substrates implanted with light ions of different fluence combinations are studied.The influence of H and He ions implantation on the a...In this work,the surface morphology and internal defect evolution process of GaAs substrates implanted with light ions of different fluence combinations are studied.The influence of H and He ions implantation on the atomic mechanism of the blister phenomenon observed after annealing is investigated.Raman spectroscopy is used to measure the surface stress change of different samples before and after implantation and annealing.Optical microscopy and atomic force microscopy are used to characterize the morphology changes of the GaAs surface under different annealing conditions.The evolution of bubbles and defects in GaAs crystals is revealed by transmission electron microscopy.Through this study,it is hoped that ion implantation fluence,surface exfoliation efficiency and exfoliation cost can be optimized.At the same time,it also lays a foundation for the heterointegration of GaAs film on Si.展开更多
We generate and measure the versatile vortex linear light bullet, which combines a high-order Bessel beam and an Airy pulse. This three-dimensional optical wave packet propagates without distortion in any medium, whil...We generate and measure the versatile vortex linear light bullet, which combines a high-order Bessel beam and an Airy pulse. This three-dimensional optical wave packet propagates without distortion in any medium, while carrying an orbital angular momentum. Its non-varying feature in linear propagation is verified by a three- dimensional measurement. Such a novel versatile linear light bullet can be useful in various applications such as micromachining.展开更多
Electrostatic discharge （ESD） induced parasitic effects have serious impacts on performance of radio frequency （RF） integrated circuits （IC）. This paper discusses a comprehensive noise analysis procedure for ESD...Electrostatic discharge （ESD） induced parasitic effects have serious impacts on performance of radio frequency （RF） integrated circuits （IC）. This paper discusses a comprehensive noise analysis procedure for ESD protection structures and their negative influences on RF ICs. Noise figures （NFs） of commonly used ESD protection structures and their impacts on a single-chip 5.5 GHz low-noise amplifier （LNA） circuit were depicted. A design example in 0.18 μm SiGe BiCMOS was presented. Measurement results confirm that significant noise degradation occurs in the LNA circuit due to ESD-induced noise effects. A practical design procedure for ESD-protected RF ICs is provided for real-world RF IC optimization.展开更多
基金funded by the Science and Technology Commission Foundation of the Central Military Commission(Grant No.2023-JCJQ-JJ-1008)。
文摘To address the challenge of achieving stable in-phase coherent optical field in high-power laser arrays,we propose a novel dual Talbot diffraction coupling method that combines the on-chip self-injection effect with a mixed-resonant cavity diode laser array(MDLA).The designed MDLA incorporates two types of resonant cavities and an integrated external fractional Talbot cavity to compensate for in-phase mode phase delays.Numerical simulations demonstrate that the nearfield optical pattern can be self-imaged via self-organized phase-locking,while the far-field optical pattern of in-phase mode can be coherently enhanced and modulated to exhibit a single-lobe pattern successfully.Furthermore,this method could inherently provide strong optical coupling and overcome the limited scalability of the weakly-coupled laser arrays.Ultimately,by leveraging self-organized phase-locking and Talbot-induced mode discrimination,our approach offers a robust platform for realizing high-power coherent laser sources with scalable integration potential.
基金the National Natural Science Foundation of China(Grant Nos.61505003 and 61674140)the Beijing Education Commission Project(Grant No.SQKM201610005008)Beijing Postdoctoral Research Foundation(Grant No.2020-Z2-043)。
文摘The room-temperature(RT)bonding mechanisms of Ga As/Si O_(2)/Si and Ga As/Si heterointerfaces fabricated by surface-activated bonding(SAB)are investigated using a focused ion beam(FIB)system,cross-sectional scanning transmission electron microscopy(TEM),energy dispersive x-ray spectroscopy(EDX)and scanning acoustic microscopy(SAM).According to the element distribution detected by TEM and EDX,it is found that an intermixing process occurs among different atoms at the heterointerface during the RT bonding process following the surface-activation treatment.The diffusion of atoms at the interface is enhanced by the point defects introduced by the process of surface activation.We can confirm that through the point defects,a strong heterointerface can be created at RT.The measured bonding energies of Ga As/Si O_(2)/Si and Ga As/Si wafers are 0.7 J/m^(2)and 0.6 J/m^(2).The surface-activation process can not only remove surface oxides and generate dangling bonds,but also enhance the atomic diffusivity at the interface.
基金This work was financially supported by the National Nature Science Foundation of China(Grant No.61673222)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.23KJB430036)Wuxi University Research Start-up Fund for Introduced Talents(Grant No.2022r036).
文摘High-quality bonding of 4-inch GaAs and Si is achieved using plasma-activated bonding technology.The influence of Ar plasma activation on surface morphology is discussed.When the annealing temperature is 300℃,the bonding strength reaches a maximum of 6.2 MPa.In addition,a thermal stress model for GaAs/Si wafers is established based on finite element analysis to obtain the distribution of equivalent stress and deformation variables at different temperatures.The shape varia-tion of the wafer is directly proportional to the annealing temperature.At an annealing temperature of 400℃,the maximum protrusion of 4 inches GaAs/Si wafers is 3.6 mm.The interface of GaAs/Si wafers is observed to be dense and defect-free using a transmission electron microscope.The characterization of interface elements by X-ray energy dispersion spectroscopy indi-cates that the elements at the interface undergo mutual diffusion,which is beneficial for improving the bonding strength of the interface.There is an amorphous transition layer with a thickness of about 5 nm at the bonding interface.The preparation of Si-based GaAs heterojunctions can enrich the types of materials required for the development of integrated circuits,improve the performance of materials and devices,and promote the development of microelectronics technology.
基金financially supported by the National Nature Science Foundation of China(Grant No.61673222)Wuxi University Research Start-up Fund for Introduced Talents(Grant No.2022r036)。
文摘In this work,the surface morphology and internal defect evolution process of GaAs substrates implanted with light ions of different fluence combinations are studied.The influence of H and He ions implantation on the atomic mechanism of the blister phenomenon observed after annealing is investigated.Raman spectroscopy is used to measure the surface stress change of different samples before and after implantation and annealing.Optical microscopy and atomic force microscopy are used to characterize the morphology changes of the GaAs surface under different annealing conditions.The evolution of bubbles and defects in GaAs crystals is revealed by transmission electron microscopy.Through this study,it is hoped that ion implantation fluence,surface exfoliation efficiency and exfoliation cost can be optimized.At the same time,it also lays a foundation for the heterointegration of GaAs film on Si.
文摘We generate and measure the versatile vortex linear light bullet, which combines a high-order Bessel beam and an Airy pulse. This three-dimensional optical wave packet propagates without distortion in any medium, while carrying an orbital angular momentum. Its non-varying feature in linear propagation is verified by a three- dimensional measurement. Such a novel versatile linear light bullet can be useful in various applications such as micromachining.
文摘Electrostatic discharge （ESD） induced parasitic effects have serious impacts on performance of radio frequency （RF） integrated circuits （IC）. This paper discusses a comprehensive noise analysis procedure for ESD protection structures and their negative influences on RF ICs. Noise figures （NFs） of commonly used ESD protection structures and their impacts on a single-chip 5.5 GHz low-noise amplifier （LNA） circuit were depicted. A design example in 0.18 μm SiGe BiCMOS was presented. Measurement results confirm that significant noise degradation occurs in the LNA circuit due to ESD-induced noise effects. A practical design procedure for ESD-protected RF ICs is provided for real-world RF IC optimization.
