The optical saturation characteristics in the germanium-on-silicon（Ge-on-Si） photodetector are studied for the first time, to the best of our knowledge. The relationship between the optical saturation characteristic...The optical saturation characteristics in the germanium-on-silicon（Ge-on-Si） photodetector are studied for the first time, to the best of our knowledge. The relationship between the optical saturation characteristics and the optical field distribution in the Ge layer is illustrated by the simulation. This theory is verified by comparative experiments with single-injection and dual-injection structures. The dual-injection photodetector with a more balanced and uniform optical field distribution has a 13% higher responsivity at low optical power and 74.4%higher saturation current at 1550 nm. At higher optical power, the bandwidth of the dual-injection photodetector is five times larger than that of the single-injection photodetector.展开更多
We have investigated the transient characteristics of discrete Raman Amplifiers and found that the response time caused by gain saturation is dependent upon the wavelength, which corresponds to the effective length of...We have investigated the transient characteristics of discrete Raman Amplifiers and found that the response time caused by gain saturation is dependent upon the wavelength, which corresponds to the effective length of the pump light.展开更多
At present,aircraft taxiing at ground airports needs to be provided with a thrust by the main engine.The taxiing process is inefficient,has high fuel consumption and serious pollution,and is prone to safety risks.In t...At present,aircraft taxiing at ground airports needs to be provided with a thrust by the main engine.The taxiing process is inefficient,has high fuel consumption and serious pollution,and is prone to safety risks.In this paper,a new configuration of aircraft autonomous traction taxiing system is proposed based on the principle of hydraulic secondary control,in which a hydraulic motor drive device is installed at the front wheels of the aircraft to drive the wheels to rotate forward or backward.Based on this,autonomous taxiing can be realized without relying on the main engines,thus greatly improving airport operation efficiency.Meanwhile,this paper analyzes the influencing factors of the autonomous traction taxiing process,and investigates the parameter matching design of the new configuration system.Besides,this paper develops the ground principle prototype,designs the aircraft longitudinal bonding force observer and the aircraft wheel disturbance moment observer,and proposes the speed control method of the aircraft front wheel autonomous traction taxiing by considering the ground bonding force saturation characteristics.Finally,the ground taxiing test is conducted,and the results show that the new configuration proposed in this paper presents a new solution for aircraft autonomous traction taxiing.展开更多
文摘The optical saturation characteristics in the germanium-on-silicon（Ge-on-Si） photodetector are studied for the first time, to the best of our knowledge. The relationship between the optical saturation characteristics and the optical field distribution in the Ge layer is illustrated by the simulation. This theory is verified by comparative experiments with single-injection and dual-injection structures. The dual-injection photodetector with a more balanced and uniform optical field distribution has a 13% higher responsivity at low optical power and 74.4%higher saturation current at 1550 nm. At higher optical power, the bandwidth of the dual-injection photodetector is five times larger than that of the single-injection photodetector.
文摘We have investigated the transient characteristics of discrete Raman Amplifiers and found that the response time caused by gain saturation is dependent upon the wavelength, which corresponds to the effective length of the pump light.
基金co-supported by the National Natural Science Foundation of China(Grant No.52205045)the National Key Research and Development Program of China(Grant No.2021YFB2011300)the Young Elite Scientists Sponsorship Program by CAST(Grant No.YESS20200063).
文摘At present,aircraft taxiing at ground airports needs to be provided with a thrust by the main engine.The taxiing process is inefficient,has high fuel consumption and serious pollution,and is prone to safety risks.In this paper,a new configuration of aircraft autonomous traction taxiing system is proposed based on the principle of hydraulic secondary control,in which a hydraulic motor drive device is installed at the front wheels of the aircraft to drive the wheels to rotate forward or backward.Based on this,autonomous taxiing can be realized without relying on the main engines,thus greatly improving airport operation efficiency.Meanwhile,this paper analyzes the influencing factors of the autonomous traction taxiing process,and investigates the parameter matching design of the new configuration system.Besides,this paper develops the ground principle prototype,designs the aircraft longitudinal bonding force observer and the aircraft wheel disturbance moment observer,and proposes the speed control method of the aircraft front wheel autonomous traction taxiing by considering the ground bonding force saturation characteristics.Finally,the ground taxiing test is conducted,and the results show that the new configuration proposed in this paper presents a new solution for aircraft autonomous traction taxiing.
