We demonstrate an all-fiber, high-power, and high stability ultrafast laser source operating at 1563 nm. A highly stable, self-starting carbon nanotube（CNT） mode-locked femtosecond fiber laser is used as the seed so...We demonstrate an all-fiber, high-power, and high stability ultrafast laser source operating at 1563 nm. A highly stable, self-starting carbon nanotube（CNT） mode-locked femtosecond fiber laser is used as the seed source. The amplifier stage uses a fiber chirped pulse amplification configuration. The main power amplifier is based on a cladding-pumped Er–Yb co-doped fiber with 10 μm active single-mode core diameter. The laser source provides 3.4 W average output power at 75 MHz repetition rate. The pulses are compressed to 765 fs by a low-loss transmission grating pair. The robust, compact, and high-power 1560 nm fiber laser source can be used for eye surgery and solar cell micromachining.展开更多
Sub-picosecond chirped laser pulse-induced airflow and water condensation were investigated in a cloud chamber.The results indicate that the positively chirped sub-picosecond laser pulses generate a more uniform inten...Sub-picosecond chirped laser pulse-induced airflow and water condensation were investigated in a cloud chamber.The results indicate that the positively chirped sub-picosecond laser pulses generate a more uniform intensity distribution inside the plasma column, leading to a weaker airflow and an elliptic-shaped snow pile. The negatively chirped sub-picosecond laser pulses generate a spark-like intensity distribution inside the plasma column, which produces a wider range of airflow and a round snow pile. The amount of snow weight and the concentration of NO3-- are found to be dependent on the intensity distribution inside the plasma column. The visibly stronger plasma column generates much more snow and a higher concentration of NO3--. These experimental results provide a reference for sub-picosecond laser-induced water condensation in realistic atmospheric conditions.展开更多
We consider a scheme to generate a sub-picosecond electron bunch in the photocathode rf gun by im-proving the acceleration gradient in the gun, suitably tuning the bunch charge, the laser spot size and the acceleratio...We consider a scheme to generate a sub-picosecond electron bunch in the photocathode rf gun by im-proving the acceleration gradient in the gun, suitably tuning the bunch charge, the laser spot size and the acceleration phase, and reducing the growth of transverse emittance by laser shaping. A nondestructive technique is also reported to measure the electron bunch length, by measuring the high-frequency spectrum of wakefield radiation which is caused by the passage of a relativistic electron bunch through a channel surrounded by a dielectric.展开更多
The authors would like to apologize for some mistakes in the article and wish to make the corrections described below：1） Designate Youjian Song （宋有建） as the corresponding author of this article. His Email addre...The authors would like to apologize for some mistakes in the article and wish to make the corrections described below：1） Designate Youjian Song （宋有建） as the corresponding author of this article. His Email address is yjsong^tju.edu.cn.展开更多
基金supported by the National Basic Research Program of China(Nos.2011CB808101 and 2010CB327604)the National High Technology Research and Development Program of China(No.2013AA122602)+2 种基金the National Natural Science Foundation of China(Nos.61322502,and 61227010,61205131,and 11274239)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20120032120071)the Tianjin Research Program of Application Foundation and Advanced Technology(No.13JCQNJC01400)
文摘We demonstrate an all-fiber, high-power, and high stability ultrafast laser source operating at 1563 nm. A highly stable, self-starting carbon nanotube（CNT） mode-locked femtosecond fiber laser is used as the seed source. The amplifier stage uses a fiber chirped pulse amplification configuration. The main power amplifier is based on a cladding-pumped Er–Yb co-doped fiber with 10 μm active single-mode core diameter. The laser source provides 3.4 W average output power at 75 MHz repetition rate. The pulses are compressed to 765 fs by a low-loss transmission grating pair. The robust, compact, and high-power 1560 nm fiber laser source can be used for eye surgery and solar cell micromachining.
基金supported by the National Natural Science Foundation of China(Nos.11425418,61475167,11404354,and 61221064)the State Key Laboratory Program of the Chinese Ministry of Science and Technology
文摘Sub-picosecond chirped laser pulse-induced airflow and water condensation were investigated in a cloud chamber.The results indicate that the positively chirped sub-picosecond laser pulses generate a more uniform intensity distribution inside the plasma column, leading to a weaker airflow and an elliptic-shaped snow pile. The negatively chirped sub-picosecond laser pulses generate a spark-like intensity distribution inside the plasma column, which produces a wider range of airflow and a round snow pile. The amount of snow weight and the concentration of NO3-- are found to be dependent on the intensity distribution inside the plasma column. The visibly stronger plasma column generates much more snow and a higher concentration of NO3--. These experimental results provide a reference for sub-picosecond laser-induced water condensation in realistic atmospheric conditions.
基金Supported by National Natural Science Foundation of China(11205152)Science Foundation of Ministry of Education of China("985 project":173123200402002)
文摘We consider a scheme to generate a sub-picosecond electron bunch in the photocathode rf gun by im-proving the acceleration gradient in the gun, suitably tuning the bunch charge, the laser spot size and the acceleration phase, and reducing the growth of transverse emittance by laser shaping. A nondestructive technique is also reported to measure the electron bunch length, by measuring the high-frequency spectrum of wakefield radiation which is caused by the passage of a relativistic electron bunch through a channel surrounded by a dielectric.
文摘The authors would like to apologize for some mistakes in the article and wish to make the corrections described below：1） Designate Youjian Song （宋有建） as the corresponding author of this article. His Email address is yjsong^tju.edu.cn.
