A time-resolved high-power laser photometer, which measures the real-time variations of transmission, internal reflection, and scattering simultaneously with picosecond time resolution, was developed to investigate th...A time-resolved high-power laser photometer, which measures the real-time variations of transmission, internal reflection, and scattering simultaneously with picosecond time resolution, was developed to investigate the material response sequence during high-power nanosecond laser irradiation in thick fused silica. It was found that the transient transmission decreased sharply, accompanied by an increase in internal reflection at the rising edge of the laser pulse. The transient transmission recovered, while laser damage did not occur, but it did not recover if the scattering increased, indicating the occurrence of laser damage. The reason for the sharp decrease of transmission and the relationship between the transmission drop and laser damage were discussed.展开更多
Laser plasmas produced by short-pulse lasers (from femtoseconds to nanoseconds) irradiating on the solid surface are intense soft X-ray (SXR) sources in the range from 100 eV to 2 keV, which are of important applicati...Laser plasmas produced by short-pulse lasers (from femtoseconds to nanoseconds) irradiating on the solid surface are intense soft X-ray (SXR) sources in the range from 100 eV to 2 keV, which are of important applications in X-ray laser researches and structure anal-展开更多
An important trend in extreme ultraviolet and soft X-ray free-electron laser(FEL)development in recent years has been the use of seeding by an external laser,aimed to improve the coherence and stability of the generat...An important trend in extreme ultraviolet and soft X-ray free-electron laser(FEL)development in recent years has been the use of seeding by an external laser,aimed to improve the coherence and stability of the generated pulses.The highgain harmonic generation seeding technique was first implemented at FERMI and provided FEL radiation with high coherence as well as intensity and wavelength stability comparable to table-top ultrafast lasers.At FERMI,the seed laser has another very important function:it is the source of external laser pulses used in pump–probe experiments allowing one to achieve a record-low timing jitter.This paper describes the design,performance and operational modes of the FERMI seed laser in both single-and double-cascade schemes.In addition,the planned upgrade of the system to meet the challenges of the upgrade to echo-enabled harmonic generation mode is presented.展开更多
基金supported by the National Key Research and Development Project of China(No.2016YFE0104300)
文摘A time-resolved high-power laser photometer, which measures the real-time variations of transmission, internal reflection, and scattering simultaneously with picosecond time resolution, was developed to investigate the material response sequence during high-power nanosecond laser irradiation in thick fused silica. It was found that the transient transmission decreased sharply, accompanied by an increase in internal reflection at the rising edge of the laser pulse. The transient transmission recovered, while laser damage did not occur, but it did not recover if the scattering increased, indicating the occurrence of laser damage. The reason for the sharp decrease of transmission and the relationship between the transmission drop and laser damage were discussed.
基金Project supported partially by the National High Technology Program
文摘Laser plasmas produced by short-pulse lasers (from femtoseconds to nanoseconds) irradiating on the solid surface are intense soft X-ray (SXR) sources in the range from 100 eV to 2 keV, which are of important applications in X-ray laser researches and structure anal-
文摘An important trend in extreme ultraviolet and soft X-ray free-electron laser(FEL)development in recent years has been the use of seeding by an external laser,aimed to improve the coherence and stability of the generated pulses.The highgain harmonic generation seeding technique was first implemented at FERMI and provided FEL radiation with high coherence as well as intensity and wavelength stability comparable to table-top ultrafast lasers.At FERMI,the seed laser has another very important function:it is the source of external laser pulses used in pump–probe experiments allowing one to achieve a record-low timing jitter.This paper describes the design,performance and operational modes of the FERMI seed laser in both single-and double-cascade schemes.In addition,the planned upgrade of the system to meet the challenges of the upgrade to echo-enabled harmonic generation mode is presented.
