High-order harmonic generation(HHG)is currently utilized for developing compact table-top radiation sources to provide highly coherent extreme ultraviolet(XUV)and soft X-ray pulses;however,the low repetition rate of f...High-order harmonic generation(HHG)is currently utilized for developing compact table-top radiation sources to provide highly coherent extreme ultraviolet(XUV)and soft X-ray pulses;however,the low repetition rate of fundamental lasers,which is typically in the multi-kHz range,restricts the area of application for such HHG-based radiation sources.Here,we demonstrate a novel method for realizing a MHz-repetition-rate coherent XUV light source by utilizing intracavity HHG in a mode-locked oscillator with an Yb:YAG thin disk laser medium and a 100-m-long ring cavity.We have successfully implemented HHG by introducing two different rare gases into two separate foci and picking up each HH beam.Owing to the two different HH beams generated from one cavity,this XUV light source will open a new route to performing a time-resolved measurement with an XUV-pump and XUV-probe scheme at a MHzrepetition rate with a femtosecond resolution.展开更多
Efficient high harmonics generation(HHG) was demonstrated at 10 MHz repetition rate with an external femtosecond enhancement cavity, seeded by a ～70 fs post-compressed 10 MHz fiber chirped pulse amplifier(FCPA) laser...Efficient high harmonics generation(HHG) was demonstrated at 10 MHz repetition rate with an external femtosecond enhancement cavity, seeded by a ～70 fs post-compressed 10 MHz fiber chirped pulse amplifier(FCPA) laser. Operation lasting over 30 min with 0.1 m W outcoupled power at 149 nm was demonstrated. It was found that shorter pulse was beneficial for alleviating the nonlinear plasma effect and improving the efficiency of HHG. Low finesse cavity can relax the plasma nonlinearity clamped intra-cavity power and improve the cavity-locking stability. The pulse duration is expected to be below 100 fs for both 1040 nm and 149 nm outputs, making it ideal for applications such as time-resolved photoemission spectroscopy.展开更多
基金the support from the special postdoctoral researcher program of RIKENthe financial support from Grants-in-Aid for Scientific Research Nos.26247068,26220606,and 19H05628+2 种基金supported by the Photon Frontier Network Programthe Special Coordination Funds for Promoting Science and Technologythe Center of Innovation Science program of the Ministry of Education,Culture,Sports,Science and Technology.
文摘High-order harmonic generation(HHG)is currently utilized for developing compact table-top radiation sources to provide highly coherent extreme ultraviolet(XUV)and soft X-ray pulses;however,the low repetition rate of fundamental lasers,which is typically in the multi-kHz range,restricts the area of application for such HHG-based radiation sources.Here,we demonstrate a novel method for realizing a MHz-repetition-rate coherent XUV light source by utilizing intracavity HHG in a mode-locked oscillator with an Yb:YAG thin disk laser medium and a 100-m-long ring cavity.We have successfully implemented HHG by introducing two different rare gases into two separate foci and picking up each HH beam.Owing to the two different HH beams generated from one cavity,this XUV light source will open a new route to performing a time-resolved measurement with an XUV-pump and XUV-probe scheme at a MHzrepetition rate with a femtosecond resolution.
基金support of the Photon Frontier Network Program of the Ministry of Education,Culture,Sports,Science and Technology(MEXT),Japan
文摘Efficient high harmonics generation(HHG) was demonstrated at 10 MHz repetition rate with an external femtosecond enhancement cavity, seeded by a ～70 fs post-compressed 10 MHz fiber chirped pulse amplifier(FCPA) laser. Operation lasting over 30 min with 0.1 m W outcoupled power at 149 nm was demonstrated. It was found that shorter pulse was beneficial for alleviating the nonlinear plasma effect and improving the efficiency of HHG. Low finesse cavity can relax the plasma nonlinearity clamped intra-cavity power and improve the cavity-locking stability. The pulse duration is expected to be below 100 fs for both 1040 nm and 149 nm outputs, making it ideal for applications such as time-resolved photoemission spectroscopy.
